Arabidopsis thaliana indicate α-amylase, in addition to the core starch biosynthetic enzymes, is also involved in the modification of glucans for the synthesis of insoluble starch granules. The simulations suggest involvement of β-amylase, in the absence of α-amylase in mutants, slows the rate of attaining a crystalline-competent CLD for crystallization of glucans to form insoluble starch. This suggests a minor role of β-amylase in shaping normal starch synthesis. The model simulation predicts that debranching of glucans is an efficient mechanism for the attainment of crystalline-competent CLD; however, attaining this is still possible, albeit slower, through combinations of α- and β-amylase in the absence of isoamylase-type debranching enzyme. In Arabidopsis defective in one of the isoamylase-type debranching enzymes, the impact of α-amylase in starch synthesis is reduced, while β-amylase becomes significantly involved, slowing the rate of synthesis in this mutant. Modeling of transient starch CLD brings to light previously unrecognized but significant effects of α- and β-amylase on the rate of transient starch synthesis.Transient starch in leaves is synthesized by various biosynthetic enzymes in the chloroplasts during the light period. This paper presents the first mathematical model for the (bio)synthesis of the chain-length distribution (CLD) of transient starch to aid the understanding of this synthesis. The model expresses the rate of change of the CLD in terms of the actions of the enzymes involved. Using this to simulate the experimental CLD with different enzyme combinations is a new means to test for enzymes that are significant to the rate of change of the CLD during synthesis. Comparison between the simulated CLD from different enzyme combinations and the experimental CLD in the leaves of the model plant  It is composed of two main fractions: amylose, mostly linear with few long-chain branches, represents between 20 to 30% of the polysaccharide dry mass; amylopectin is the main component and is highly branched, with around 5% α-(1→6) branch points Starch in the photosynthetic tissues of plants such as leaves serves as one of the principal sinks for carbon fixed during the day and is degraded during the subsequent night to provide a continued supply of sugars to sustain respiration and growth. Starch is solely made up of glucose residues linked by α-(1→4) linked glucose residues from the non-reducing end. There are two groups of SSs in plants: granule-bound SSI (GBSSI) and the soluble SSs. The soluble SSs are principally involved in elongation of amylopectin branches while GBSSI is mainly involved in amylose biosynthesis. Starch branching enzymes (SBEs) are responsible for generating new amylopectin branches via α-(1→6) branch points, by cleaving an α-(1→4) linkage on a donor chain and transferring the donor segment to a new α-(1→6) position, forming a new branch. There are minimum chain length requirements (constraints) on the number of glucose units on both the donor and the residual segments for branching to proceed  linkages, releasing linear or branched glucans Arabidopsis, both AtISA1 and AtISA2 genes are required to produce the heteromeric multsubunit complex, named Iso1, which contribute to the major isoamylase activity et al. et al. X<8–12, depending on the species (e.g. α-(1→6) linkages, and only accounts for a minor role in transient starch synthesis Arabidopsis ISA2 and PUL-type DBE double mutant Atisa2/Atpu1, starch content is further reduced compared to that in just the absence of Iso1 in mutants defective in AtISA1 or AtISA2, which suggests some partial redundancy between the two DBE types Transient starch biosynthesis in leaves requires the concerted actions of various types and isoforms of starch biosynthetic enzymes eed e.g. ; these mies e.g. . The rolα- and β-amylolysis α-amylase (AMY) (EC 3.2.1.1) is an endoamylase hydrolyzing α-(1→4) linkages to release soluble glucans, either linear or branched. While AMY is known to be the main enzyme involved in the degradation of storage starch granules during cereal seed germination, its role may differ in transient starch degradation in leaves Arabidopsis with only one chloroplasticly localized AMY3 (AtAMY3) et al. et al. While the above enzymes are the key actors essential for starch synthesis, hypotheses have emerged that other types of enzymes could contribute to transient starch synthesis under specific circumstances. For example, in the absence of all DBEs, glucans are susceptible to β-amylase (BAM), hydrolyzes every second α-(1→4) linkage from the non-reducing end to release maltose. BAM stops hydrolysis 2–4 glucose residues ahead of a branch point on the glucan branches generated by the branch points, or on those that carry other branch points. It is the major enzyme for transient starch granule breakdown in leaves. Lack of BAM leads to a starch-excess phenotype in the leaves of potato and Arabidopsis which is caused by a slow rate of degradation of starch over the dark period β-phosphate from ATP to a glucosyl residue in the C-6 and C-3 position, respectively Arabidopsis chloroplasts and has been described as being involved in starch metabolism in Chlamydomonas reinhardtiiArabidopsis DPE mutant accumulates starch at a normal rate Arabidopsis remains unclear. Finally, it was shown in Chlamydomonas and rice that starch phosphorylase (SP) (E.C 2.4.1.1) is involved in storage starch synthesis An exoamylase, Nde(X) of glucan chains with DP of X (the subscript “de” is used because these glucan chains are obtained from isoamylase-type debranching enzyme digestion of the starch). The quantity X = 1,2,3, … is a discrete variable. To avoid proliferation of subscripts, we use the notation Nde(X) on the understanding that X only takes integer values There are several features in the CLD, for example as shown in Arabidopsis starch CLD also exhibits several features (The starch chain-length distribution (CLD) is the relative number distribution features .Arabidopsis) by considering the actions of the biosynthetic enzymes involved. This new modeling would appear to provide an innovative and powerful option for identifying and testing candidate enzymes that have not previously been considered to be involved in starch biosynthesis. Comparison between experimental data for Arabidopsis and the model simulation suggests that, in addition to the core starch biosynthetic enzymes, α-amylase is also involved in the synthesis of insoluble starch granules. In the absence of Iso1, β-amylase becomes significantly involved. Furthermore, modeling of transient starch CLD reveals an unexpected role of α- and β-amylase in transient starch synthesis in Arabidopsis.This paper presents the first mathematical model to describe transient starch CLD /∂t, in terms of the actions of the enzymes that are assumed to be involved in the modification of glucans which then crystallize and deposit to form insoluble starch granules. Whether or not an enzyme is considered to be involved for the purpose of this model is defined by whether or not the corresponding mutant possesses an altered starch CLD. The following discusses the evidence for the enzymes considered in the model and the reasons why others are not. The properties of enzymes described in the following are based on their general properties and not species specific. This allows a general mathematical model of starch CLD to be developed and is then used to compare with experimental data for Arabidopsis. The results, which will be specific to Arabidopsis, will be seen to provide further understanding of starch biosynthesis in Arabidopsis and perhaps more generally.The model expresses the rate of change of the glucan CLD at time ∂Nde(X)/∂t during the synthetic phase. Mutations in all of the three enzyme types show changes in the starch CLD (e.g. (1) SS, SBE and the DBEs, the core enzymes, undoubtedly contribute to CLD e.g. . Storageα-amylase contributes to ∂Nde(X)/∂t during the synthetic phase. Arabidopsis AtAMY3 knock-out mutant has been generated α-amylase contributing to ∂Nde(X)/∂t. The exact contribution of AMY to ∂Nde(X)/∂t, however, is a complex one. Just to give a few examples, AMY is modulated by the presence and clustering of α-(1→6) branch points and higher structures . As there are a vast number of structural possibilities for the substrates, it is currently impossible to determine the exact substrate specificity of AMY over the entire course of starch biosynthesis. At the very least, the time evolution of α-(1→6) linkage positions would need to be considered during starch synthesis, which would give information on the position of the branches, to partly capture the contribution of AMY to ∂Nde(X)/∂t. However, this information is not currently available. With such uncertainty, it is best to consider, in this first approach, only the most probable mechanism of AMY towards starch biosynthesis. As stated, glucans that are yet to crystallize represent the newly formed layer of material on starch molecules and as such are most susceptible to enzymatic actions. It has been shown that these materials comprise mainly short A-chains (DP 6–11) α-(1→6) linkage that carries the branch exerts effects on the enzyme. Refinement of this assumption may be necessary for the long B-chains and beyond where there are higher structural features which can influence the contribution of AMY. For example, clusters of branch points hinder AMY, so AMY would preferentially hydrolyze α-(1→4) linkages away from the clusters.(2) There is no indication whether Arabidopsis β-amylase mutants have been generated by Fulton et al. α-(1→6) branch points and phosphate residues on glucan branches block BAM α-(1→6) linkage and phosphate residues positions. Therefore, the exact contribution of BAM to ∂Nde(X)/∂t cannot be established. As with α-amylase, we assume that when a branch is hydrolyzed by BAM, only the α-(1→6) linkage that carries the branch has an effect on β-amylolysis.(3) α-(1→4) or α-(1→6) linkages. Therefore we can conclude that GWD and PWD do not contribute to ∂Nde(X)/∂t directly. An indirect effect is possible if BAM is involved in the synthesis of transient starch. In which case, its exoamylasic activity can be blocked by the phosphate residues which come from phosphorylation by GWD and PWD. This could, however, be considered as marginal, as typically only one in 2000 glucose residues is phosphorylated (e.g. Arabidopsis leaf starch at the end of the synthetic phase) ∂Nde(X)/∂t. In addition, a mutation in the GWD encoding gene that leads to amylopectin with no phosphorylation in Arabidopsis gives no significant difference in the amylopectin CLD (4) There is no indication that GWD and PWD participate directly in the synthesis or hydrolysis of et al. Arabidopsis DPE mutant. Therefore, we conclude that DPE does not contribute to ∂Nde(X)/∂t. This contrasts with Chlamydomonas reinhardtii, where DPE mutant exhibits an increase in X = 3–5 (5) Critchley Chlamydomonas, mutation in one of the three SP affects the starch CLD by causing a reduction in X = 6–13. Whether SP has the same effect in Arabidopsis is unknown. In theory, the contribution of SP to ∂Nde(X)/∂t is either the same or opposite of SS, depending on whether SP polymerizes or depolymerizes glucan chains, respectively. Therefore, we assumed that it either adds or counters the rate of glucan elongation, respectively. This simply means the predicted rate of glucan elongation would be a combined rate of SS and SP. The overall rate, however, would have to be a positive contribution to propagation, or otherwise starch synthesis would not be possible.(6) In ∂Nde(X)/∂t with respect to the contributions of SS, SBE, DBE, AMY and BAM. Note that DBE(i) refers to both the ISA- and PUL-type DBE. They are not differentiated in this model since both facilitate the hydrolysis of α-(1→6) linkages. To rigorously define the enzymatic activities of the enzymes involved we would need to consider factors such as pH change, temperature, availability of light, substrate specifies and substrate and products concentrations. One way would be to study the enzyme kinetics for the different factors and set out rate equations to describe enzymatic activities in terms of the appropriate factors. However, this would give an undesirably large number of parameters and would cause the model to always be able to be forced to agree with experiment, and would thus be irrefutable, which is scientifically disfunctional ∂Nde(X)/∂t in the enzyme set (i) range (Features A′–B′ in Arabidopsis leaf starch is given by Eqn 1. The right-hand side includes the contributions from SS(i), SBE(i), DBE(i), AMY(i) and BAM(i). The evolution equation governing ∂Nde(X)/∂t in the enzyme set (i) range (Features A′–B′ in Arabidopsis leaf starch is given by Eqn 1. The right-hand side includes the contributions from SS(i), SBE(i), DBE(i), AMY(i) and BAM(i).Considering the above, the synthesis of the transient starch CLD in leaves is modeled by formulating aSS(i), with units of s–1. aSBE(i) is that for branching by SBE(i) in enzyme set (i), with units of s–1; aDBE(i), aAMY(i) and aBAM(i) are those for debranching, α- and β-amylolysis, respectively, all with the same units as aSBE(i). H(y) is a step function: H(y)  = 0 for y<0,  = 1 for y≥0, and appears because of the various constraints for SBE(i), AMY(i) and BAM(i) (see Introduction and above). The Kronecker delta Xδ,3 is 1 for X = 3, and zero otherwise , and expresses that when branches are hydrolyzed by AMY, they are assumed to reduce to X = 3 only. H(X–3) for BAM indicates the shortest branches produced are X = 3 from X = 5, hence H(X–5) for the other BAM term in Eqn 1. The reason for X = 3 is because it is the shortest branch length with a significant amount in the CLD (The enzymatic rate coefficient for glucan elongation by the addition of ADP-glucose by SS(i) and possibly SP(i) is  the CLD .Eqn 1 can be conveniently presented in matrix form as given in Eqn 2.Nde(t) is a column vector whose entries comprise Nde. Ω is the rate coefficient matrix, whose elements comprise the rate coefficients on the right hand side of Eqn 1 divided by aSS(i). The elements of Ω are dimensionless ratios of the enzymatic rate coefficients, denoted by β(i)  =  aSBE(i)/aSS(i), γ(i)  =  aDBE(i)/aSS(i), ε(i)  =  aAMY(i)/aSS(i) and δ(i)  =  aBAM(i)/aSS(i); these, plus X0(i) and Xmin(i), are the six model parameters for the enzyme set (i) component of the CLD.Arabidopsis leaf starch, the CLD is in a steady state X is independent of time . Wu et al. ∂Nde(t)/∂t  =  ΩNde  = 0. Nde(t), the solution of Eqn 2, a homogenous first order differential equation, is given by Eqn 3, as described elsewhere (e.g. There is evidence that during the synthesis of ere e.g. .(3)i is the ith eigenvalue of Ω and ui is the corresponding eigenvector. Eigenvalues and eigenvectors are defined by the relation Ωu  =  λu, where u is a non-zero vector. ic is given by Eqn 4, which is a system of linear equations. Nde(t = 0) is a column vector whose entries comprise Nde, which give the CLD at the beginning of the period in question. The eigenvalues and eigenvectors of Nde(t) for the enzyme set (i) component are controlled by the six model parameters (see above).where λNde(t) evolves in time to the eigenvector corresponding to the zero eigenvalue. This zero-eigenvalue condition means only a defined range of the enzymatic rate ratios (i.e. β(i), γ(i), ε(i) and δ(i)) are allowed To attain a steady-state CLD, there must be at least one zero eigenvalue while the rest of the eigenvalues are negative. This condition ensures that Nde(t) is as follows. Eqn 3 shows that the time evolution of Nde(t) is described by the eigenvalues and the corresponding eigenvectors. When the zero-eigenvalue condition is satisfied, Nde(t) evolves to the eigenvector corresponding to the zero eigenvalue over time. When this happens, Nde(t) is then at a steady state. The time for this to happen depends on the values of the rest of the eigenvalues. If there are eigenvectors that correspond to less negative (close to zero) eigenvalues, they decay relatively slowly, which means a steady-state Nde(t) will require a relatively longer time to reach. Conversely, eigenvectors that correspond to more negative eigenvalues decay rapidly.A way of interpreting the time-evolution of Arabidopsis leaf starch CLD within the enzyme set (i) range (Features A′–B′) from the wild-type (WT CLD) and the ISA-type DBE mutant defective in the AtISA1 gene (Atisa1-1 CLD) were non-linear least squares fitted to the solution of Eqn 1, Nde (β(i), γ(i), ε(i), δ(i), X0(i) and Xmin(i). 1, Nde . Data weArabidopsis leaf starch CLD shows a number of distinct features. ∂Nde(t)/∂t: for example, for storage starch in cereal endosperms, an enzyme set would be made up of one each of the various isoforms of SS, SBE and DBEs (both the ISA- and PUL-type DBE) or of these enzymes having different activity arising from their complexation state, post-translational modification, or other temporally or physically distinguished regulatory effects Arabidopsis leaf starch CLD are as follows, with the labels chosen to be consistent with that used previously X = 3–5), which are not seen in storage starch and must be due to additional enzymatic activity. Features A and B are ascribed to enzyme set (i). Feature A is due to one of the SBE(i) chain length requirements, X0(i), and covers a range of X of between X0(i) and Xmin(i). Feature B is the global maximum which is due to the other chain length requirement, Xmin(i), and lies between Xmin(i) and X0(i) + Xmin(i). Feature B′, not consistently observed in storage starches, is a small bump which may perhaps involves synthesis by an additional enzyme set. Feature C corresponds to the range of Arabidopsis leaf starch CLD beyond the “discontinuity” consistently observed at X = 17–18 Arabidopsis leaf starch CLD is more prominent than in, for example, maize and rice endosperms , were only given up to a range in Feature C (X≈30). It may be that the higher X range were not shown because of the limitations of HPAEC  when capillary electrophoresis was used instead.The features of rms e.g. , while bArabidopsis leaf starch CLD model considers the actions of SS(i), SBE(i), DBE(i), AMY(i) and BAM(i) in enzyme set(i). When both AMY and BAM are involved in addition to the core enzymes, it is designated as AMY+/BAM+; AMY–/BAM– means neither are involved. A combination of AMY and BAM  were tested by fitting to the Arabidopsis CLD data (The CLD data . Fitted X≤5), in WT CLD  for the first case , but a significant increase in δ(i) with AMY+/BAM+ compared to that for AMY+/BAM– for the wild type Arabidopsis .There is no significant difference in Features B and B′ between the wild-type and ISA-type DBE mutant bidopsis . All fitarch CLD , the addAtisa1-1 CLD with the different combinations of the amylases (Nde(t) . The eigenvalues are either real or complex numbers with non-zero imaginary component; the imaginary components always appear in pairs with opposite sign, so the actual value of Nde(t) is real but with some transient oscillations. It is proposed that the time evolution of the CLD before a steady state is reached is described by Eqn 3. Data for this may be observed if the CLD of the glucan at the periphery of starch granules are isolated and characterized.AMY and BAM have effects on the relative rate of steady-state CLD attainment. amylases . The ful–/BAM+ generated relatively small negative eigenvalues compared to AMY+/BAM– and AMY+/BAM+ , γ(i), ε(i) and δ(i)) that satisfy the zero-eigenvalue condition which is required to attain a steady-state CLD. In each case, the extreme case was considered: one or more of the enzymatic rate ratios is set to zero while allowing others to vary until the zero-eigenvalue condition was satisfied. β(i)  = 0 was not tested because SBEs are indispensible for amylopectin synthesis. There are eight combinations of zero and non-zero values of γ(i), ε(i) and δ(i) which are shown in We tested the range of the enzymatic rate ratios (i.e. γ(i), ε(i) and δ(i) are all zero, the zero-eigenvalue condition can be satisfied. This indicates, given SS and SBE, a steady-state CLD can be attained with any of the combinations of DBE, AMY and BAM. The combination SS, SBE and DBE has been shown in our previous paper to satisfy the zero-eigenvalue condition for storage starch α-and β-amylase (AMY and BAM), that had not been previously thought to be involved in the starch biosynthesis pathway.This paper presents the first mathematical model for the synthesis of transient starch in leaves. The model considers the synergic actions of SS, SBE, DBE, the enzyme set considered to be responsible for the steady-state attainment of glucan CLD for crystallization of the amylopectin structure for insoluble starch granule formation. This work also described an innovative approach where the model also included enzymes, Arabidopsis, we discovered that the core enzymes  are necessary but not sufficient to produce the CLD seen in the wild-type Arabidopsis. Indeed, WT CLD showed an extra Feature A′ which suggested the presence of additional enzymatic activity. By including different enzymes into our mathematical model, we discovered that Feature A′ could only be predicted by a form of the model which includes the involvement of AMY. This supports our assumption that AMY mainly acts on short A-chains (DP 6–11) in the newly formed layer of material on starch molecules and not on glucans deposited in the semi-crystalline structure of starch. It is reasonable to assume that this structure is less accessible to further enzymatic modification.By comparing the simulated CLD obtained with our mathematical model to the CLD produced in normal transient starch synthesis in the wild-type +/BAM– to the WT CLD, the model implies that AMY is responsible for the presence of Feature A′. However, further characterization using Arabidopsis ISA-type DBE mutant CLD suggested that both AMY and BAM were involved with BAM contributing to the elevated Feature A′ and A in the ISA-DBE mutants.From the fit by AMYArabidopsis, AMY is involved in starch synthesis but BAM is not. Indeed, according to our model, AMY is the enzyme responsible for the presence of Feature A′, the very short chains in the CLD. The presence or absence of BAM in our model did not influence this Feature. This suggests that AMY would act along with the ISA-type DBE to ensure the trimming of the pre-amylopectin to finalize starch crystallization.Our model suggests that, in the wild-type Arabidopsis transitory starch metabolism et al. α-amylase in Arabidopsis, is redox catalyst activated by light. Hypotheses emerged around a potential role AMY in a stress-response mechanism. However, having the unique chloroplastic AMY active during daylight could also imply a role in the synthetic phase.Concerted actions of different classes of hydrolysase have been described in α-amylolysis can be seen as a complementary pathway. Indeed, AMY has the potential to hydrolyze α-(1→4) linkages further away from the non-reducing ends of glucan branches, thereby yielding shorter glucan stubs. These shorter glucan stubs may become susceptible to DBEs  linkage from the non-reducing ends. When BAM act on the highly branched polysaccharide produced in the ISA-type DBE mutant, it produces glucan stubs varying in lengths, which may not be the optimal substrate for debranching and may delay crystallization  that β-amylolysis is a less efficient mechanism for transient starch synthesis. However, the additional involvement of AMY (i.e. AMY+/BAM+) restored the rate of steady-state attainment to that of the wild-type Arabidopsis (AMY+/BAM–). Interestingly, Arabidopsis AMY knock-out mutant showed no significant change in the rate of starch accumulation in the leaves compared to the wild-type plant –/BAM–.The simulations suggest that the rate of steady-state CLD attainment would be the slowest with AMY–/BAM+ is also predicted to yield the slowest rate of steady-state CLD attainment. However, the model predicts that when the involvement of BAM is removed (AMY+/BAM–), the rate of steady-state CLD attainment is comparable to that in the wild-type Arabidopsis. This not only suggests that BAM is detrimental to the rate of steady-state CLD attainment, but it could act preferentially on the highly branched polysaccharide produced in the ISA-type DBE mutant, reducing the efficiency of complementing enzymes, for example, the PUL-type DBE.In the ISA-type DBE mutant, AMYThere is a wide spread in the eigenvalues in the ISA-type DBE mutant with the different combinations of AMY and BAM. This suggests that when the ISA-type DBE is involved, the rate of starch synthesis is insensitive to the involvement of the different combinations of AMY and BAM. This implies the ISA-type DBE is the main regulator of the rate of steady-state CLD attainment required for the formation of insoluble starch. In our model, AMY seems to have a significant but limited effect and BAM would only be detrimental to the rate of steady-state CLD attainment.Arabidopsis transient starch synthesis from the eigenvalues. (1) A way of interpreting the zero-eigenvalue condition of the model is that steady-state CLD attainment in the wild-type Arabidopsis requires the simultaneous involvement of both the synthetic enzymes (i.e. SS and SBE) and the degradation enzymes  to support starch synthesis. The degradation enzymes can be regarded as responsible for CLD  editing in order for the CLD to attain a steady state. (2) In the wild-type Arabidopsis, ISA-type DBEs are the preferred enzymes to carry out the structural editing. This is inferred from the finding that when the DBE is involved, the rate of stead-state attainment is insensitive to the other structural editing enzymes, AMY and BAM. It appears that hydrolysis of α-(1→6) linkages by DBEs is an effective structural editing mechanism for supporting crystallization for starch synthesis. This is consistent with the fact that a large number of DBE mutants result in reduced or abolished starch synthesis and cause the accumulation of water-soluble glucan (phytoglycogen). Mutations in other types of structural editing enzymes do not exhibit such striking phenotypes. For example, there was no report of phytoglycogen in the AMY +/BAM+ are less negative compared to those in the wild-type plant (see above). This indicates the relatively rate of steady-state CLD attainment in the ISA-type DBE mutant is slow compared to the wild-type plant. This is the first indication of the possibility that crystallization of glucans is slower in DBE mutants, as proposed by Myers et al. et al. There are several inferences we can make about the roles of AMY and BAM in Arabidopsis mutant lacking all DBEs  and AMY (a quintuple mutant), starch granule synthesis is still observed Model simulations showed in the case of a complete absence of all DBEs, the involvement of either AMY or BAM or both is able to satisfy the zero-eigenvalue condition for the attainment of a steady-state CLD. This explains why in the Atisa1-1 CLD and simulated CLD with AMY+/BAM+ Click here for additional data file.Figure S2The full list of eigenvalues as mentioned in .(DOCX)Click here for additional data file.


The study examines the effects of maltodextrins saccharified to various degrees on some rheological properties of potato starch dispersions. Pasting characteristics, flow curves, and mechanical spectra were determined for native potato starch and for its blends with potato maltodextrins having dextrose equivalents (DE) of 10.5, 18.4, and 26.5. The results showed that medium-saccharified maltodextrin (DE = 18.4) gave the strongest effect, manifesting itself as a considerable reduction in the viscosity at pasting, a decrease in apparent viscosity during flow, and a decrease in the storage and loss moduli. Addition of high-(DE = 26.5) or low-(DE = 10.5) saccharified maltodextrins had a markedly smaller effect on the rheological properties of starch. The differences in the effects produced by the maltodextrins are closely connected to the degree of polymerisation of the maltooligosaccharides in the systems. Starch, one of the most common polysaccharides, has a number of specific properties that make it highly useful in the food industry and other sectors of the economy. It belongs to the cheapest thickening agents, texturizers, filling agents, and stabilizers. Heating starch granules in water environment causes them to paste. When they release amylose in the process, starch loses its specific granular structure –3. The cIn the temperate climatic zone countries, such as Poland, potatoes are an important source of starch. Potato starch differs from cereal starches mainly in the size and structure of granules , 11, amyKnowledge of the rheological properties of starch pastes and gels is of vital importance to the food industry and other sectors utilizing starches as a raw material , 22. SinPotato starch was obtained from PZZ Piła, Poland, and potato maltodextrins were provided by CLPZ Luboń, Poland. The maltodextrins were saccharified to different degrees: low , medium , and high . The dextrose equivalent (DE) was determined by Lane-Eynon's method according to the relevant Polish Standard (PN-EN ISO 5377:2001). The mean degree of polymerization (DP) was calculated on the basis of dextrose equivalent values: DP = 111/DE.Rheological studies were conducted at constant concentration of starch (5 g d.w./100 g). The starch-maltodextrin systems were produced by dissolving an appropriate amount of maltodextrins  in distilled water and then adding starch.The pasting characteristics of both native starch and starch-maltodextrin blends were determined in a Brabender viscograph, type 801201 (Germany) with a measuring cup of 250 cmg at a rotation speed of 75 rpm. The systems studied were heated and then cooled at a rate of 1.5°C/min using the following procedure: raising temperature from 25 to 96°C, maintaining constant temperature of 96°C during 20 minutes, reducing temperature from 96 to 50°C, and maintaining constant temperature of 50°C during 10 minutes. The viscograms obtained were used to read pasting temperature, peak viscosity, temperature at peak viscosity, viscosity at 96°C, viscosity after 20 minutes at 96°C, viscosity at 50°C, and viscosity after 10 minutes at 50°C.−1. The experimental curves were described employing Herschel-Bulkley equation:τ is the shear stress (Pa), −1), τ0 is the yield stress (Pa), K is the consistency coefficient (Pa · sn), and n is the flow behavior index.Samples for rheometric investigations were prepared by heating the suspension of starch or starch with each maltodextrin at temperature of 95°C for 30 minutes while stirring it continuously at a rate of 250 rpm. Next the hot paste was placed in the measuring element of the rheometer, relaxed, and thermostated during 15 minutes at the temperature of measurement. Flow curves at 50°C were obtained by using a rotational rheometer Rheolab MC1  with a coaxial cylinders system  for the shear rate range of 1–300 sMechanical spectra at 25°C were determined by using a Rheostress RS rheometer  with a cone-plate system . The measurements were made in the linear viscoelasticity range at a constant strain of 0.03 in the frequency range of 0.1–10 Hz.α = 0.05.Statistical assessment was done by performing a one-way analysis of variance and calculating the least significant difference (LSD) at −1) (−1) . The flo−1) . The con−1) . The gre−1) . In cont−1) . When th−1) . During G′) were higher than those of the loss modulus (G′′). However, the storage modulus did not display a plateau that is characteristic for strong gels and depended on frequency over whole study range, with the values of tg δ = G′′/G′ amounting to about 0.48. The various maltodextrins added to the starch differently affected its viscoelastic properties. Low-saccharified maltodextrin in the amount of 1 g/100 g caused an apparent decrease in both moduli, as compared to the gel of native starch  had the greatest effect on starch pasting characteristics, flow behavior, and viscoelastic properties. The contribution of the maltodextrins to the formation of starch pastes and gels was closely associated with their degree of polymerization. High-(DP = 4.2) and medium-(DP = 6.0) saccharified maltodextrins hindered the formation of the structure of starch pastes and gels. Low-saccharified maltodextrin  added to the starch affected its rheological properties to a much smaller extent than medium-saccharified maltodextrin. This could be attributed to the fact that maltooligosaccharides of DP exceeding 6, which are able by themselves to form amylose helices, participated in the formation of the structure of starch pastes and gels.


Ex vivo Vein graft ENgineering via Transfection IV (PREVENT IV) cohort was 25%, suggesting that early graft failure is a significant problem  harvested for autotransplantation. Interventions for proposed –12. Addiproposed , 13–15.Marking of the SV graft using a surgical skin marker in an “off-label” fashion represents another such preparation technique and is the most commonly employed method of preventing graft torsion . This main vitro live–dead assay. The study found that marking caused pronounced cell death and inhibited tenocyte migration, representing a total failure of explant vigor -O-(4-benzoylbenzoyl)adenosine-5′-triphosphate (BzATP), was added to an organ bath containing suspended unprepared human SV rings left as untreated control or pretreated with a topical FCF. The FCF-treated rings demonstrated reduced BzATP-induced, P2X7-governed contractile responses, suggesting that P2X7 receptors were inhibited (7 receptor activation leads to increases in intracellular calcium concentrations (7 activation, as detected by a FluoroPlex apparatus (Evidence of FCF-governed P2Xnhibited . P2X7 retrations . Furtherpparatus .via the CytoTox-Glo assay, in contrast to the effects observed with topical gentian violet and isopropyl alcohol (We have also examined the topical effect of FCF on vascular conduit. Human SV samples were obtained from CABG patients prior to preparation or preservation, and baseline physiologic responses were determined in an organ bath . The dec alcohol .In addition to its effects on acute physiologic responses and cellular viability of vascular tissue, we have also reported the influence of FCF treatment on intimal hyperplasia . UnmanipThe “off-label” use of surgical skin markers have been shown to impair physiologic responses in human SV graft and to be cytotoxic. Surgeons should consider minimizing or eliminating the off-label use of surgical skin markers for vein marking. FCF is a plausible alternative dye for graft marking in that it preserves endothelial and smooth muscle function and inhibits neointimal growth in human SV. Moreover, FCF is also the only dye that is currently approved by the FDA for use in marking human SV.EW contributed to research and writing of the manuscript. JC-F contributed to research and critical revision of the manuscript. CB oversaw all respects of the research and composition of the manuscript. All authors gave final approval.JC-F and CB have a proprietary interest in VasoPrep Surgical, Inc. EW has no conflicts of interest to disclose.


Dictyostelium discoideum amoebas require cellulose synthase for formation of multicellular fructifications with cellulose-rich stalk and spore cells. Amoebas of its distant relative Polysphondylium pallidum , can additionally encyst individually in response to stress. Ppal has two cellulose synthase genes, DcsA and DcsB, which we deleted individually and in combination. Dcsa- mutants formed fruiting bodies with normal stalks, but their spore and cyst walls lacked cellulose, which obliterated stress-resistance of spores and rendered cysts entirely non-viable. A dcsa-/dcsb- mutant made no walled spores, stalk cells or cysts, although simple fruiting structures were formed with a droplet of amoeboid cells resting on an sheathed column of decaying cells. DcsB is expressed in prestalk and stalk cells, while DcsA is additionally expressed in spores and cysts. We conclude that cellulose is essential for encystation and that cellulose synthase may be a suitable target for drugs to prevent encystation and render amoeba pathogens susceptible to conventional antibiotics.Amoebas and other freely moving protists differentiate into walled cysts when exposed to stress. As cysts, amoeba pathogens are resistant to biocides, preventing treatment and eradication. Lack of gene modification procedures has left the mechanisms of encystation largely unexplored. Genetically tractable  Dictyostelium discoideum and Acanthamoeba castellani, the structural component is cellulose , a single cellulose synthase gene is essential for the construction of multicellular fruiting bodies, by synthesizing a cellulose stalk tube and the cellulose-rich walls of individual stalk cells and spores , can alternatively encyst as single cells. Ppal also constructs architecturally more complex fruiting structures than D.discoideum with multiple regular whorls of side branches.In the social amoeba d spores . Many DiPpal cyst wall  genome contains a single cellulose synthase gene, DcsA, and we first investigated whether DcsA is conserved throughout the dictyostelid phylogeny. The genomes of species representing the four major groups of Dictyostelia and the solitary amoebozoan Acanthamoeba castellani (Acas)  and Ppal, which represent the two major clades of group 2. The dictyostelid cellulose synthase genes were more similar to bacterial and oomycete cellulose synthases than to the Acas cellulose synthase.The i (Acas)  as well Ppal is the only encysting dictyostelid that is amenable to gene knockout procedures. To identify the respective roles of DcsA and DcsB in Ppal, we generated null mutants in either gene by transformation with a floxed neomycin cassette (DcsA or DcsB coding regions. Clones carrying gene knock-out (KOs) and random integration (RI) events were identified by two PCR reactions and Southern blot analysis .The group 2 species cassette  flanked Ppal dcsa- KO cells, formed fruiting bodies with normal stalks . This construct, 1.6p::DcsA, restored cellulose deposition in spore walls  than dcsa- spores (1.4 ± 0.2) and wild-type spores (1.8 ± 0.13), suggesting that DcsB still contributes somewhat to spore wall integrity and shape maintenance. The cells at the periphery of the dcsa-/dcsb- “spore” mass appeared to be lysed and showed weak staining throughout, which is probably caused by interaction of Calcofluor White with intracellular polysaccharides.We next disrupted the ll walls A. This s sorogen B e, f. T sorogen B g-i, wh sorogen B h, thaten  were fused to the LacZ reporter gene in plasmid pDd17 gal and transformed into Ppal wild-type cells. Developing structures were stained with X-gal to visualize activity of the cognate LacZ gene product, β-galactosidase. The DcsA 3.0 kb promoter activated LacZ expression in most cells in aggregates  decrease in the number of colonies formed by wild-type, random integrant and dcsb- cysts (80-90% of plated cells). However, both the dcsa- and dcsa-/dcsb- cyst equivalents formed hardly any colonies in the absence of detergent treatment and none in its presence. Apparently, the dcsa- and dcsa-/dcsb- spore equivalents are viable, but not detergent resistant in the absence of cellulose, while the dcsa- and dcsa-/dcsb- cyst equivalents are entirely non-viable.We next assessed how loss of reatment . The dcsD. discoideum, such as the slime sheath that surrounds the migrating slug, the walls of spore, stalk and basal disc cells and the supportive tube that surrounds the stalk cells. A single enzyme, DcsA, produces cellulose for all these features and its deletion prevents the formation of viable spores and of a stalk to lift the sorus from the substratum . It is plausible that the group 2 Polysphondylids with their habitually long thin stalks  and incubated at 106 cells/cm2 on PB agar (1.5% agar in PB).DcsAandDcsBsingle and double knock-out mutants: To obtain a DcsA knock-out plasmid, KO fragments DcsA I and II (Supplementary figure S1) were amplified from Ppal PN500 genomic DNA using primer pairs DcsAI5′/DcsAI3′ and DcsAII5′/DcsAII3′ , respectively, introducing XbaI/BglII sites on fragment I and HindIII/XhoI sites on fragment II. The fragments were sequentially inserted into the XbaI/BamHI and HindIII/XhoI digested plasmid pLox-NeoIII  were similarly amplified with primer pairs DcsBI5′/DcsBI3′ and DcsBII5′/DcsBII3′ and inserted in pLox-NeoIII, yielding plasmid pDcsB_KO. The XbaI/XhoI inserts from the pDcsA_KO and pDcsB_KO plasmids were excised and 5 μg of either insert was transformed into 2.5 x 106Ppal cells together with 2 nanomoles of its flanking primers , followed by selection of transformants on autoclaved K.aerogenes at 300 μg/ml G418  was amplified by PCR using primer DcsAPro1_5′ and DcsA3′, which include XbaI and HindIII restriction sites, respectively . After XbaI/HindIII digestion, the fragment was ligated into similarly digested plasmid pExp5  as the 5′primer, and inserted in pExp5, yielding 3.0p::DcsA.id pExp5 , yieldinDcsAandDcsBpromoter-LacZ constructs: The 1.6 and 3 kb DcsA promoter fragments and a 2.7 kb DcsB promoter fragment  were amplified from Ppal genomic DNA using primer pairs DcsaPro1_5’/DcsApro3′, DcsaPro2_5′/DcsApro3′ and DcsB Pro5′/DcsBpro3′ , respectively. The 5′ and 3′ primers contain XbaI and BamHI restriction sites, respectively, which were used to insert the constructs into the BglII/XbaI digested vector pDdGal17  or are available on request.pDdGal17 . This geeviously . All plaCyst and spore germination assay: To obtain spores, Ppal wild-type cells and mutants were harvested from growth plates and incubated at 22 °C on PB agar for 4 days until mature fruiting bodies had fully formed. For cysts, cells were resuspended in encystation medium (PB with 400 mM sorbitol) and incubated for 4 days in the dark until wild-type cells had formed mature cysts. Spores and cysts, harvested from fruiting bodies and encystation medium, respectively, were resuspended in 80 mM sucrose in PB (K.aerogenes on 1/5th SM agar plates at 500 cells per 15 cm plate. Colony numbers were counted after 3 days of culture at 22 °C.se in PB  and coun


Although most theoretical models of household decision making assume perfect information, empirical studies suggest that information asymmetries can have large impacts on resource allocation. I demonstrate the importance of these asymmetries in transnational households, where physical distance between family members can make information barriers especially acute. I implement an experiment among migrants in Washington, DC, and their families in El Salvador that examines how information asymmetries can have strategic and inadvertent impacts on remittance decisions. Migrants make an incentivized decision over how much of a cash windfall to remit, and recipients decide how they will spend a remittance. Migrants strategically send home less when their choice is not revealed to recipients. Recipients make spending choices closer to migrants' preferences when the migrants' preferences are shared, regardless of whether or not the spending choices are revealed to the migrants, suggesting that recipients' choices are inadvertently affected by imperfect information. For example, Although the implications of asymmetric information have been well documented in the study of economic institutions such as labor, credit, and insurance markets, theoretical models of intra-household resource allocation have largely assumed perfect information .1 Despitstrategic behavior, meaning that migrants and recipients recognize that the asymmetry exists and use it for their benefit. The specific asymmetries considered here are the limited abilities of remittance recipients to observe migrant income and of migrants to observe recipient spending. The second type are those that can have inadvertent impacts, defined as asymmetries that unintentionally affect decisions. These asymmetries are represented here as communication barriers that result in recipients having an incomplete understanding of migrant preferences for how the remittances they send should be spent. Communication barriers should be interpreted broadly as any obstacle—social, financial, or logistical—to understanding these preferences.I address two types of information asymmetries that may affect decisions about the sending and spending of remittances. The first are asymmetries that can lead to The context of transnational households is significant because migrants and their family members are making financial decisions in a situation where information asymmetries are especially acute due to the distance separating family members. A number of studies have documented the existence of these asymmetries in households with migrants. The importance of understanding how information asymmetries affect decisions in transnational households is heightened by the fact that migrants and their family members are financially linked through the sending of remittances. In 2010, aggregate remittances to the developing world were US$332 billion, and in El Salvador remittances received were 16% of GDP . AdditioA growing experimental literature related to remittances and information has focused on the strategic efforts of migrants to control remittance spending. Specifically, several field experiments have examined the effects of offering migrants varying degrees of control over remittances. The idea behind these experiments is that offering control to migrants will mitigate a moral hazard problem in how recipients spend remittances. Studies have found mixed results. both sides of the migrant–recipient relationship. The observational studies documenting information asymmetries in migrant households have also largely focused on migrant monitoring of recipient behavior , and those whose decisions were not revealed to their families at home . Although the choice was described to the migrant as a remittance decision, it should be noted that the migrant experiment is essentially a version of the classic dictator game where one player allocates a sum of money between him or herself and a recipient.The experiments in this paper explicitly test for both strategic and inadvertent responses to information asymmetries. They were designed to mimic real-life decisions about remittances made by migrants and their family members, and by randomly assigning treatments, I am able to causally identify the impacts of the informational conditions being tested. The first experiment was conducted among Salvadoran migrants recruited in the Washington, DC, area.The migrants' family members in El Salvador (referred to throughout the paper as “recipients”) then participated in a second experiment. They made a decision about how to spend a possible $300 lottery prize. This prize was referred to as a remittance and recipients were told that they were eligible for this remittance because their migrant family member was participating in the study. To test for strategic reactions to the observability of their spending choices, as in the migrant experiment half of the recipients were told that their choice would not be revealed to the migrant, and the other half were told that their choice would be revealed. In a second cross-randomized treatment addressing the inadvertent effects of communication barriers, half of the recipients were informed of the migrant's preferences for how the money should be spent, and the others were not. These preferences were collected from migrants during the migrant survey, following the conclusion of the migrant experiment described above. In order to avoid the migrant experiment influencing the results of the recipient experiment, the information revelations about choices made in the migrant experiment and the awarding of all prizes were conducted after the conclusion of both experiments.I find that migrants remit $20 more on average out of the possible $600 lottery prize (an increase of 5% over the control group mean of $440 sent) when their decisions are revealed. I additionally report suggestive evidence that this effect is concentrated among migrants whose baseline characteristics indicate that they may be likely to react strategically to the opportunity to hide income from their family members. These characteristics include time spent in the United States, relationship between the recipient and the migrant, whether the migrant has a child 22 or under in El Salvador, frequency of communication between the migrant and the recipient, and remittances sent by the migrant to the recipient. There is no corresponding evidence of strategic behavior in the recipient experiment. Therefore, despite the focus on migrant monitoring of recipient behavior in the existing literature, I find that migrants, but not recipients, react strategically to whether or not their choices will be monitored. In the second recipient treatment reducing communication costs by revealing migrant preferences to recipients does have an impact, resulting in a 10% reduction in the difference between migrant preferences and recipient choices. The effect is present even when recipient choices are not revealed to migrants. This result demonstrates that information barriers can have inadvertent impacts on remittance decisions.3 People in developing countries often transfer resources within extended families, and therefore decisions about resource allocation are likely to involve people beyond just the husband and wife. These results show that information asymmetries can have important impacts in extended families.In addition to its principal contributions to the literature on information issues in migrant families, this study also builds on the existing household literature more generally. For example, most papers focus on only a single choice in the resource allocation process, and the present experiment considers how information asymmetries can affect a sequence of two different decisions made by families about economic resources. Additionally, this study documents that information asymmetries can be important outside of the husband–wife pair, which has been the context of most previous experimental work in this area.Because the design of the migrant experiment is essentially a modified dictator game it is also important to understand how this study differs from the extensive existing literature on dictator games. Dictator games are generally used as a test for altruistic behavior and are played anonymously, with neither the dictator nor the recipient knowing the identity of the other. Results generally show that dictators deviate from pure self-interest and allocate around 20% of the available funds to the recipient . Studies4The migrant experiment can be thought of as a dictator game with known recipients that studies the impact of revealing dictator choices similar to studies such as The paper proceeds as follows: Section 2 describes a simple conceptual framework. Section 3 explains the experimental design. Section 4 describes the data and the empirical strategy. Section 5 presents the results, and Section 6 concludes.5 The idea is that migrants are compelled to send more in remittances than they would choose to if simply motivated by altruism because they want to avoid incurring these costs. One example of such a cost is social sanctions against the migrant: many migrants come from areas with strong social norms regarding remittances and particularly for migrants who wish to return home one day, a damaged reputation could be quite costly. Empirical support for social norms and recipient pressure driving remittances includes 6In this section I describe a simple economic framework that motivates the experimental design. The migrant's decision about how much to send home in remittances is driven by two factors: altruism towards the recipient and additional costs that vary with the remittance amount. These costs are broadly construed and meant to encompass most other motivations for sending remittances previously considered in the literature.7 but in many cases they must rely only on what the migrant has told them. Therefore, migrants for whom these costs are important can strategically take advantage of situations where recipients cannot observe their true income to underreport their earnings and send less home.The expected remittance payment depends on the recipient's perception of the migrant's incomes. For example, if migrants are earning more, social norms may dictate that larger amounts should be sent home. Similarly, recipients will perceive migrants to be more altruistic the larger the proportion of their overall income that is remitted. The extent to which recipients have knowledge of migrants' true incomes will vary. In some circumstances recipients may have independent information about how much the migrant has earned,The decision made by recipients about how to spend the remittances that they receive is considered in a parallel manner to the migrant sending decision. Recipients choose the extent to which they follow the migrants' preferences for how remittances should be spent. Their choice is motivated by altruism (in this case simply the extent to which recipients want to follow migrant preferences) and other costs related to the recipient's decision. For example, failure to comply with migrant preferences could lead to a reduction in remittance funds in the future. As with the migrant decision, recipients can therefore strategically take advantage of circumstances when their spending is unobservable by spending less money according to migrant preferences.communication costs, but the concept is broader than the cost of a telephone call. With distance, specificity about preferences may become difficult, migrants may feel uncomfortable expressing what they want, and recipients may sometimes have to make decisions without time to directly consult with migrants. Family members may also incorrectly assume that they know what the migrant would prefer. If the recipient does not know the migrant's preferences, the preferences will not be followed regardless of the recipient's intentions.The recipient decision may additionally be complicated by barriers to communication that result in confusion over what the migrant's preferences actually are. I will refer to these barriers as Given that information asymmetries in transnational families are difficult to measure and may be correlated with a number of unobserved characteristics, I implement a randomized experiment to test for their strategic and inadvertent impacts. This experiment is conducted within the context of survey work for a separate field experiment on remittances and education among Salvadoran migrants in Washington, DC, and their families in El Salvador . The det8Migrants were recruited in the Washington, DC, metro area at the two area locations of the Salvadoran consulate and were interviewed while they were waiting for consular services. The migrant survey was conducted between late September 2011 and late February 2012. Surveyors in the consulate approached migrants and invited them to participate. Because the focus of the companion experiment was remittances and education, participants were required to name a high school or college-aged relative or acquaintance in El Salvador. Those who qualified and agreed to participate were administered a baseline survey. The migrant experiment described in this paper was conducted at the end of the survey. Following the experiment, the migrants responded to an additional question to be used in the recipient experiment.During the survey migrants identified a high school or college-aged student in El Salvador. Interviews were subsequently conducted with the student or a household member. If the student was 18 years of age or older, the student was to be interviewed; and if under 18, a guardian was identified to be interviewed. If the indicated person was not available, an alternative adult in the household was interviewed. The El Salvador survey was conducted by phone in the days following the migrant survey in the United States; the median number of days between surveys was eight. The El Salvador surveys concluded in mid-March 2012, two weeks after fieldwork ended in the United States. The experiment in the El Salvador survey was also at the end of the survey. The randomization in this study was performed at the participant level. Surveys were pre-assigned treatment status, and randomization for all treatments was stratified within groups of 16 surveys and by the treatment offered in the companion experiment. The recipient treatments were additionally stratified by the migrant treatment.9 More than half the migrants who participated in this study report earning less than $400 a week. Consequently, $600 represents a significant increase in monthly income. The question text can be found in The migrant experiment consisted of an incentivized remittance-sending decision. Migrants were told that they were being given the chance to win a $600 lottery and would have to decide how much of the prize to keep for themselves and how much to remit to their family member in El Salvador. Migrants could split the $600 as they wished but were restricted to using $100 intervals for simplicity. The prize was awarded through a lottery and two prizes were given out. If asked, surveyors told migrants the number of prizes and the date of the drawing.Migrants were randomly allocated into two groups: those who were told that their choice would be revealed to their family member, and those who were told that their choice would not be revealed. For those in the choice revealed treatment group, all recipients were to be informed about the migrant's choice, regardless of whether or not they won the lottery. Recipients in the choice not revealed group were told nothing about the migrant experiment unless the migrant won the lottery and had elected to send the recipient some or all of the $600. The family member referred to in the question was the person to be surveyed in El Salvador. A description of the treatments is presented in This experiment exogenously varies the probability that recipients will observe migrant income and measures the extent to which migrants strategically take advantage of asymmetric information. The framework described in Section 2 predicts that migrants whose choice is not revealed to the recipient should send less than those whose choice is revealed.10 As the goal of the experiments was to emulate real life remittance decisions it was necessary to use money amounts that were close in magnitude to the sums participants would be considering when making these real life decisions. Given the average size of remittance payments in this population and budgetary restrictions, the lottery method was the only feasible method of conducting the study. This method has been used in many prior studies such as 1112Because the prize was awarded through a lottery, participants were not guaranteed any winnings and the expected value of the prize for each participant was quite low.13 This knowledge of the migrants' preferences will allow for a direct examination of how closely recipients adhere to these preferences.The recipient experiment consisted of an incentivized remittance spending decision. The respondents in the El Salvador phone survey were told that because their family member in the United States participated in the study, they now had the chance to win a lottery for a remittance worth $300. They had to decide what to spend the remittance on and were asked to split the $300 among four spending categories: restaurant meals, education, daily expenses, and health expenses. Recipient choices were limited to four categories for simplicity in the context of a phone survey. Immediately following the migrant experiment, during the US survey (which occurred prior to the recipient interview), all migrants were told about the lottery for recipients and asked what their preferences were for how the recipients would spend the money.14 Prizes were awarded in kind and respondents were held to the choices that they made. In practice this meant that project staff coordinated the delivery of the selected prize with each lottery winner on a case by case basis. Some choice was permitted within the categories the recipients had chosen but they could not request prizes outside of those categories. The median monthly remittance reported by participating migrants is $220, so a $300 remittance is a reasonable amount for many recipients. The question text can be found in Those recipients who won the lottery received exactly the allocations that they requested. Four prizes were awarded. If asked, surveyors told the recipients the number of prizes and the date of the drawing.The recipient monitoring treatment is parallel to the migrant monitoring treatment. Recipients were randomly allocated into two groups: those who were told that their choice would be revealed to the migrant, and those who were told that their choice would not be revealed to the migrant. Recipients knew that all migrants in the choice revealed treatment would be informed of their decision whether or not they won the lottery. Migrants in the choice not revealed group were told nothing. This treatment randomly varied the probability that recipient spending would be observed and measures the extent to which recipients strategically take advantage of this asymmetric information. Following the conceptual framework, the results of the experiment should show that recipients make choices closer to migrant preferences when those choices are revealed to the migrant.As described above, during the US survey, migrants were told about the lottery for recipients and asked what their preferences were for how the recipients would spend the money. This information is utilized as part of this treatment. Recipients were randomly allocated into two groups: those for whom the migrant's preferences were revealed and those for whom the migrant's preferences were not revealed. Making these preferences clear is a proxy for improving communication, so the experiment exogenously improves communication about migrant preferences for expenditures. Revealing migrant preferences to the recipient should decrease the difference between the recipients' choices and the migrants' preferences when communication problems exist.not revealed to the migrant.This treatment was designed as a test of whether or not communication costs can lead to inadvertent deviation from migrant preferences by the recipient. In order to make this argument convincing it is necessary to consider its interaction with the monitoring treatment. Specifically, if recipients are both uninformed and strategic, one would expect to only see effects for those recipients who are both told the migrants' preferences and told that their choices will be revealed. Conversely, a pure inadvertent effect can only be identified if there is an effect of the communication treatment for those recipients whose choices were The migrants are half female with an average age of 38. The mean number of years in the United States is 11, so the migrants are largely established in the United States. 32% of migrants report having a son or daughter aged 22 or under in El Salvador, and 69% report communicating with the recipient household at least weekly. The sample is also low income; half of the migrants earn $400 a week or less. Because of the structure of the project, the interviewed recipients are either the student identified by the migrant (45%) or the student's guardian if the student is under 18 (40%). The remaining 15% of interviews were done with a different adult in the household if the student or guardian could not be reached. The recipient sample is heavily female (68%) because identified student guardians tend to be female.15 To address the external validity of the sample, in Because migrants were screened into the study on the basis of having a young adult relative in El Salvador, it is possible that the respondents are not representative of the larger migrant community. This concern is heightened by the fact that many migrants were not eligible to participate because they did not know a student of the appropriate age. During recruitment, among the migrants approached 24% participated. Of those that did not participate, a considerable majority, 77%, did not know an eligible student in El Salvador.A related concern is that even if the migrants themselves are similar to the broader population of migrants in the area, the student age requirement results in migrants naming El Salvador households with which they are not typically in a remittance relationship. The evidence from the baseline survey refutes this. 85% of migrants have remitted to the recipient household in the past year and 78% of recipients are members of the migrant's home household in El Salvador. 64% send more to the recipient household than other households, indicating that the recipient household is the primary remittance recipient in the majority of cases. I also examine the relationship of the migrant to the recipient. A tabulation of these relationships is presented in The results of the migrant experiment can be analyzed by estimating the following regression using ordinary least squares:iRemit is the dependent variable indicating the amount that the migrant chose to send to the recipient. iChoiceRevealed is the treatment indicator for the monitoring treatment, and it is equal to one when the migrant's choice is revealed to the recipient. The coefficient α is the average difference between how much migrants choose to send when their decisions are not revealed and when they are revealed. iγ are the stratification cell fixed effects. There are 111 survey group stratification cells in all regressions. I also include specifications with controls. The control variables include migrant age, gender, education, household size, years in the United States, remittances to recipient household, and other migrant background characteristics. iε is the error term, which I adjust for heteroskedasticity.where 16The recipient experiment was designed to understand the impacts of information asymmetries on the extent to which recipients follow migrant preferences for the expenditures of remittances. Because the migrant survey collected the migrant's preferences for the recipient's choices for all participants, it is possible to directly examine this parameter by comparing migrant preferences with recipient choices. I implement this by calculating the absolute value of the difference between the recipient's choice and the migrant's preference in each category. I also create a summary measure across the four categories by summing the difference variables and dividing by 2 to scale the total to 300. I refer to this as the total difference, and it is the primary dependent variable of interest. It is a measure of the number of dollars out of the $300 on which migrant and recipient choices match. For example, a total difference of 100 would mean the recipient's choices matched the migrant's preferences on $200 of the $300, but that they allocated the remaining $100 to different categories.An alternative estimation strategy would be to examine average recipient allocations to each spending category. However, in order to detect treatment effects using this strategy, migrant and recipient preferences would have to be different in the sample on average, for example if migrants overall preferred education while recipients preferred daily expenses. If migrants and recipients instead have approximately the same preferences on average, these averages can conceal substantial within-pair disagreement. Examination of only changes in average recipient allocations may then mask substantial changes in recipient behavior that will be evident when analyzing within-pair differences. Consequently, I focus on the pair-level differences, but discuss the impacts on average recipient allocations in The recipient experiment can be analyzed by estimating the following regression:iDifference is the difference between migrant preferences and recipient choices in each of the four spending categories or the total difference. iChoiceRevealed is the treatment indicator for the recipient monitoring treatment and is equal to one when the recipient's choice is revealed to the migrant. iPreferenceRevealed is the treatment indicator for the communication treatment and is equal to one when the migrant's preferences are revealed to the recipient before the recipient decides how to allocate the remittance funds. iChoiceRevealed * iPreferenceRevealed is the interaction between the two treatments. If, as predicted, revealing the recipients' choices to the migrants and communicating the migrants' preferences to the recipients causes the recipients to make choices more similar to the migrants' preferences, even when the other treatment has not been applied, then the difference variable will be smaller in the choice revealed and preference revealed treatment groups, and β1 and β2 should be negative. If recipients react to being monitored more when the migrants' preferences are revealed (in other words they are both strategic and uninformed), then the interaction term will be important and β3 should be negative. iθ are the stratification cell fixed effects (survey group and migrant treatment). I also present a specification with control variables and use the same variables as in the migrant experiment as well as recipient gender, age, education, household size, and the number of days between the migrant and recipient surveys. iμ is the error term, which I adjust for heteroskedasticity.where 17I first analyze the results of the migrant experiment in which migrants decide how much of a potential $600 lottery prize to send to the recipient and how much to keep. These results are formalized in The fact that almost all migrants in the not revealed treatment chose to send something and that most chose to send the entire potential prize suggests that the altruistic component of remittances is high. However, the differences between the two treatment groups are evidence that information asymmetries and strategic behavior also play a role. Given that the framework discussed in Section 2 suggests that this strategic behavior will occur when migrants react to costs incurred when sending less than expected, it is instructive to examine whether or not the impact of the information treatment varies in remittance relationships where these costs may be more or less important.18 To allow comparability with the binary proxies , I create binary measures of the continuous variables (years in the United States and remittances) by splitting the sample at the sample median.19 These are certainly not perfect measures, and the analysis is limited by the fact that these characteristics were not randomly assigned and that it was not possible to stratify the information treatment on these characteristics.20I utilize five variables from the baseline survey as proxies for situations where these costs may be more important: years in the United States, migrant has a child 22 or under in El Salvador, migrant and recipient are closely related, migrant communicates with recipient household weekly, and remittances sent to recipient household. The general motivation for choosing these proxies is that they are indicative of relationships where remittance norms may be higher, migrants may be more likely to have entrusted the recipient with the care of family or investments, and migrants may be more concerned about recipient perceptions of their behavior. A detailed description of the rationale for choosing these variables is provided in 21 It should also be noted that while these results are supportive of the notion that migrants send more than they would if they were solely motivated by altruism, I cannot specifically differentiate between the possible strategic motivations, such as the migrant's desire to appear fair or pressure from recipients to send larger amounts home.To examine how the impact of the monitoring treatment may have varied with each of these proxies, I re-estimate regression The results in Additionally, the effect size is similar to the size of the correlations with the demographic variables in The migrant experiment found that migrants react strategically to variations in the ability of recipients to monitor their income. Previous literature has suggested that migrant monitoring of recipients should also be important . To look22 Daily expenses are the next most popular category, followed closely by health and finally restaurant meals. Migrants allocate less to education than recipients and more to the other categories, but no clear evidence indicates that migrants strongly prefer different expenditure categories than recipients.Mean amounts allocated to different spending categories by recipients and migrants are presented in 23I utilize the data collected from both the migrant and the recipient to analyze how the treatments affect the pair-level differences between their choices.The results presented in Differences are evident for the communication treatment. For all spending categories, the coefficient on the main effect of the variable indicating that the migrant preference was revealed to the recipient is negative. This means that the differences between recipient choices and migrant preferences are smaller when the migrants' preferences are revealed than when they are not, even when the recipient choices were not revealed to the migrant. Of all the spending categories, only the difference for education (column 3) is statistically significant, but importantly, so is the total difference (columns 5 and 6), implying that migrant and recipient choices are getting closer together overall. Across specifications the results indicate that there is a $14 reduction in the total difference when the migrant's preferences are revealed and the recipient's allocation will not be shared with the migrant. This represents a 10% reduction relative to the mean in the group where neither the recipient's choice nor the migrant's preference was revealed. The effect is driven by the difference in education spending, largely because education spending is by far the most preferred category.The first result from the recipient experiment is that the monitoring treatment has no impact on the difference between migrant preferences and recipient choices. This implies that recipients do not react strategically to variation in whether or not their choices will be observed. The framework presented in Section 2 proposes an explanation for why recipients may not take advantage of the opportunity to hide their spending choices from migrants. The costs that would induce recipients to react to being monitored may simply be low across the population. In practice, this would result in a situation where recipients are not compelled to spend remittances according to migrant preferences beyond what they choose to do altruistically.Although low costs associated with remittance spending decisions are a convincing explanation for the lack of effect of the monitoring treatment, it is important to consider other possible explanations. The first alternative explanation is that migrant monitoring of recipients is essentially perfect and that recipients know that their choices will be discovered if they win. However, only 24% of migrants correctly report student GPA and 43% correctly report how students travel to school ; therefo24The second result from the recipient experiment is that revealing migrant preferences decreases the difference between migrant preferences and recipient choices even when the recipient choice will be not be revealed to the migrant. This suggests that migrant preferences do matter to recipients and that some deviation from those preferences may be inadvertent. A potential criticism of this result is that recipients are simply reacting to being given a suggested allocation for the choice they are making and may have reacted in the same way even if the preferences were attributed to someone besides the migrant. I address this concern by examining heterogeneity in the effects of the communication treatment by proxies for the quality of information in the relationship. Specifically, in Although the experimental methodology used in this paper allows for the causal identification of the effects of information asymmetries, it is important to consider how the experimental context could distort participant behavior relative to real life. The first potential issue is experimenter-demand effects, the idea that because participant decisions in the experiment are measured by the experimenter participants may act in a more pro-social manner than they would if their choices were truly anonymous. This question has been widely explored through a series of lab experiments that vary whether or not participant choices are observable to the experimenter. Experimenter-demand effects can also play a role in the recipient communication treatment. Recipients may, for example, feel obliged to follow migrant preferences because the surveyor will observe their choice. Again, there is no way to rule this out, but given that there is no impact of the migrant monitoring treatment, in order for experimenter-demand effects to explain a large portion of the observed effect of the communication treatment, recipients would have to respond much more strongly to scrutiny by the surveyors than to observation by the migrants themselves.The second issue is that the prize money in the experiment is a onetime windfall as opposed to regular earned income. Studies that have examined earned versus unearned windfall income have found that people are more generous with unearned winnings (for example 25The final issue is that of the fungibility of choices made during the experiment. Both migrants and recipients could potentially undo their choices during the experiment through their actions afterward. For example, migrants could choose to not send a remittance that they would have sent otherwise. Although some of this behavior may be occurring, it is not necessarily important for the interpretation of the treatment. If the results show differences between the two treatments then that is evidence that people are reacting to variations in information.both sides of the remittance relationship—migrants' sending of remittances as well as recipients' spending of those remittances. Despite the previous emphasis on migrant monitoring, the results of the two monitoring treatments presented in this paper are that, in this context, only migrants strategically react to variations in the probability that their actions will be monitored.This paper analyzes a set of experiments designed to test for the effects of information asymmetries in transnational households. Economic studies of information asymmetries in households with migrants have until now focused on migrant monitoring of recipient behavior and the impacts of offering migrants greater control over how remittances are spent. This is the first study that explicitly looks at the effect of information asymmetries on 26 Because migrants control the flow of remittances they send to their family members, documenting this recipient influence is important precisely because it goes against the prior that those who control the money are necessarily in the best bargaining position. Policymakers who seek to design tools to facilitate the sending of remittances and enhance their impacts should consider the role of the recipient in determining remittance amounts.This is an important finding, not only because it shows that information asymmetries have an important impact on the remittance sending decision, but also because this suggests that recipients have important influence in the migrant–recipient relationship.The analysis in this paper indicates that because migrants are responding to the opportunity to hide income, some of them are already sending home more than they would choose to altruistically. This implies that programs that seek to further increase remittances may face difficulties within this group. Policymakers should also consider the welfare implications of such a policy. The pressure that migrants face to send remittances is related to a growing literature on sharing pressures in family networks in developing countries. Recent work by Overall, the findings that information asymmetries can affect both the sending and spending of remittances suggest that interventions or technological innovations that improve communication in transnational households could have important effects on financial decisions made by both migrants and recipients. In particular, the results of the communication experiment imply that for migrants who wish to change the spending behavior of their family members, policies that improve communication about spending preferences may be an inexpensive way to achieve a higher level of compliance with their preferences.This discussion assumes that alleviating inadvertent information asymmetries in transnational households increases welfare. However, if, for example, migrant preferences are based on old or misinformation, encouraging the recipient to follow such preferences may actually have negative impacts on the recipient household. This, combined with the strategic behavior of migrants in the migrant experiment, suggests that the welfare effects of alleviating information asymmetries are complex. While this paper documents the importance of these information issues, further research should more carefully investigate their welfare implications in both transnational and coresident households.Supplement


Trunk flexibility may be associated with arterial stiffness in young, middle-aged, and older healthy men after adjusting for blood pressure. This study assessed the effects of 4 weeks of regular static stretching on arterial stiffness in middle-aged men. Sixteen healthy men (43 ± 3 years) were assigned to control or intervention groups (n = 8 each). The control group did not alter their physical activity levels throughout the study period. The intervention group participated in five supervised stretching sessions per week for 4 weeks. Each session comprised 30 min of mild stretching that moved the major muscle groups through the full range of motion and stretches were held three times for 20 s at the end range. Flexibility was assessed by sit-and-reach test. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV) and cardio-ankle vascular index (CAVI). Four weeks of stretching increased sit-and-reach , and reduced baPWV  and CAVI  in the intervention group. However, the change in sit-and-reach did not significantly correlate with the changes in arterial stiffness. These findings suggest that short-term regular stretching induces a significant reduction in arterial stiffness in middle-aged men. Pulse wave velocity (PWV) is frequently used as an index of arterial stiffness, and large elastic artery stiffness is progressively greater with advancing age even in healthy people , aortic PWV, and cardio-ankle vascular index (CAVI), and poor trunk flexibility is related to greater arterial stiffening  , and none of them participated in regular exercise program for at least 2 years. The participants did not take any medications. The men were matched for age and physical characteristics, especially in PWV as nearly equal as possible and assigned to either a control or an intervention group (n = 8 each). Thus, the participants were not provided with the option to self-select their group allocation. The purpose, procedures, and risks of the study were explained to all of them and they provided written informed consent before participating in the study, which was reviewed and approved by the Human Ethics Committee at the Prefectural University of Kumamoto (24-002) and proceeded in accordance with the guidelines of the Declaration of Helsinki.We determined the appropriate sample size for each group before starting the study by power calculations using SPSS Sample Power  and assumed that the maximal reduction in arterial stiffness after intervention would be 4–7 % according to the previous results  at the same time of day and at the same number of hours after the last meal to avoid potential diurnal variations. The participants were required to abstain from caffeine and fast for ≥4 h before each test and then were assessed at least 24 h after the most recent stretching session to avoid any acute effects.Body composition was determined by bioelectrical impedance using a TBF-410 instrument  as described in our previous study  were assessed using an automated VS-1500AE/AN device  as described  as described at least twice after stretching  with a precision of 0.1 kg . Measurements were made in duplicate, and the highest value in the stronger hand was taken  translated into Japanese  repeated-measures analysis of variance (ANOVA). When the F value was significant, the Bonferroni method was applied for post hoc multiple comparisons. Relationships between flexibility and arterial stiffness were assessed using Pearson’s correlation. Results were regarded as statistically significant at P < 0.05.Results are presented as mean ± standard error of the mean (SEM). Bartlett’s test and Levene’s test were firstly performed to confirm the normal distribution of the data. Parameters before the experiment and physical activity levels between the two groups were compared using an independent Student’s


Conflicts of interest arising from ties between pharmaceutical industry and physicians are common and may bias research. The extent to which these ties exist among editorial board members of medical journals is not known. This study aims to determine the prevalence and financial magnitude of potential conflicts of interest among editorial board members of five leading spine journals. The editorial boards of: The Spine Journal; Spine; European Spine Journal; Journal of Neurosurgery: Spine; and Journal of Spinal Disorders & Techniques were extracted on January 2013 from the journals’ websites. Disclosure statements were retrieved from the 2013 disclosure index of the North American Spine Society; the program of the 20th International Meeting on Advanced Spine Techniques; the program of the 48th Annual Meeting of the Scoliosis Research Society; the program of the AOSpine global spine congress; the presentations of the 2013 Annual Eurospine meeting; and the disclosure index of the American Academy of Orthopaedic Surgeons. Names of the editorial board members were compared with the individuals who completed a disclosure for one of these indexes. Disclosures were extracted when full names matched. Two hundred and ten (29%) of the 716 identified editorial board members reported a potential conflict of interest and 154 (22%) reported nothing to disclose. The remaining 352 (49%) editorial board members had no disclosure statement listed for one of the indexes. Eighty-nine (42%) of the 210 editorial board members with a potential conflict of interest reported a financial relationship of more than $10,000 during the prior year. This finding confirms that potential conflicts of interest exist in editorial boards which might influence the peer review process and can result in bias. Academia and medical journals in particular should be aware of this and strive to improve transparency of the review process. We emphasize recommendations that contribute to achieving this goal. The spinal surgery community has recently witnessed serious controversies and discussion concerning possible bias in scientific reports on the effects of a commercially available bone morphogenetic protein. This has compromised the standing of this community, and it was the direct reason for performing this study –4. FinanBoth editorial board members and reviewers are involved in editing the content of manuscripts and the decision to accept or reject the manuscript (often after revision following editor/reviewer suggestions) for publication. This process of editing of- and deciding on manuscripts can be influenced by numerous factors including the perspective of an editorial board member, degree of knowledge or experience with the topic under study and conflicts of interest –21. ConcAlthough several publications have demonstrated the occurrence of bias in the peer review process as a result of conflicts of interest, it is not clear to what extent this exists in editorial boards , 14, 22.The Spine Journal; Spine; European Spine Journal; Journal of Neurosurgery: Spine; and Journal of Spinal Disorders & Techniques .–34.th InThese meetings and indexes were chosen because of the large number of participants, exclusive focus on spinal topics, and availability of disclosure statements. Disclosure statements were not available for: Canadian Spine Society; British Association of Spinal Surgeons; American Spinal Injury Association; Nordic Spinal Deformities Society; British Scoliosis Society; Brussels International Spine Symposium; and International Congress on Early Onset Scoliosis.Disclosing for these meetings and indexes was mandatory for participants for reasons including (but not limited to): speaking engagements –33; abstDisclosures considered to constitute a potential conflict of interest according to the respective societies included (but were not limited to) ownership, payments and reimbursements for: personal or professional services; stock or shareholder ownership; consulting (paid or unpaid); trips; travel; fellowship support; royalties; patents; gifts; grants and research support. Disclosures such as payments and reimbursements for governing boards of journals or societies and for medical publications were excluded, as these might be related to the function of editorial board member.The editorial offices of the five journals were contacted and asked to provide the disclosures of their editorial board members; only one office responded and stated that the disclosures were considered confidential. The Spine Journal lists disclosures of the executive editorial board on their website (9 editors) .To determine whether editorial board members had a potential conflict of interest, we compared the full names of all editorial board members with the names of all individuals who completed a disclosure statement for the NASS, IMAST, SRS, AOSpine, or Eurospine and extracted the disclosures when full names matched –31, 33. The disclosures were categorized in: (1) potential conflict of interest (as specified in the previous paragraph), (2) nothing to disclose/no conflict reported , and (3) no disclosure statement listed for one of the meetings or indexes. The disclosure index of the NASS from 2013 contained the amount of financial relationship per disclosure . Using tThe disclosure statements were searched for financial relationships with the six leading orthopedic/spinal medical device companies: Biomet, Smith and Nephew, Stryker, Zimmer, Medtronic, Johnson & Johnson, the latter including subsidiaries DePuy and Synthes .A total of 716 editorial board members could be identified on the websites of the five spine journals representing 595 unique individuals  & Fig 1.Two hundred and ten (29%) of the 716 editorial board members reported a potential conflict of interest and 154 (22%) reported nothing to disclose/no conflict reported, during the meetings in 2013 . The remThe prevalence of reported potential conflicts of interest ranged from 20% for editorial board members of the European Spine Journal to 69% for editorial board members of the Journal of Neurosurgery: Spine. However, the percentage of retrieved disclosure statements of editorial board members varied largely; ranging from 39% for the European Spine Journal to 71% for the Journal of Spinal Disorders & Techniques. More than half of the traced editorial board members of every individual journal—except for Spine—reported a potential conflict of interest.Eighty-nine (42%) of the 210 editorial board members with a potential conflict of interest reported a financial relationship of more than $10.000 . The amoThe majority, 159 of the 210 (76%) editorial board members that reported a potential conflict of interest had a financial relationship with one of the six leading medical device companies .The potential conflicts of interest per region varied and was 64% (167 out of 259) for North American, 48% (38 out of 79) for European, 19% (4 out of 21) for Asian, 100% (1 out of 1) for Australian, and 0% (0 out of 4) for South American editorial board members with a disclosure listed for one of the meetings or indexes. The three editorial board members from Africa had no disclosures listed. However, the Asian (6.8%), Australian (2.0%), South American (1.7%), and African (0.04%) continents were quite underrepresented .Financial and nonfinancial relationships between industry and editorial board members generate a dilemma: although ties between pharmaceutical or medical device industry and the scientific journals are considered essential for sharing state-of-the-art scientific knowledge and moving the field of medicine forwards, these ties may at the same time create conflicts of interest, compromise the objectivity of the review process, and result in bias , 14, 22.This study has limitations, and the results should be interpreted with care. Our aim was to investigate whether we could find potential conflicts of interest but the methods we used cannot be considered comprehensive. Firstly, disclosure requirements varied among meetings and indexes and participants might have deemed their conflicts of interest irrelevant to disclose . For exaThe question arises whether this existence of potential conflicts of interest among editorial board members is confined to the field of spine surgery. The journals with the highest impact factors in the field of cardiology and general medicine were screened for online availability of editorial board disclosures. Plos Medicine, the Annals of Internal Medicine and the Journal of the American College of Cardiology are among the highest ranked journals within their field and have online disclosures listed of their executive editorial boards. Disclosures of other editorial board members  are not listed on the websites of these journals. Four out of 10 editors in Plos Medicine reported a potential conflict of interest 40%), 3 out of 7 editors in Annals of Internal Medicine reported a potential conflict of interest (43%), and 15 out of 17 editors in the Journal of the American College of Cardiology (88%) reported a potential conflict of interest %, 3 out . FurtherIn this study we have focused on the conflict of interest based on financial relationships of editorial board members. We have not studied other potential conflicts, such as between competing researchers within a field. It is possible and even likely that reviewer/editor and author are competing in the same research field where first publications, citations and grant funding is very competitive. This might bias the editor or reviewer in the peer review process, leading to delayed publication or rejected manuscripts.Conflict of interest of editorial board members has gained substantial attention over the past 10 years. Haivas et al. (2004) surveyed the senior editors of 30 general medicine journals and demonstrated that 19 (63%) felt it was important to declare the financial conflicts of interest of their editors; 13 43%) felt that this was important for all of their editorial board members and 11 (37%) for other editorial advisers % felt th–48. HoweWe found that a substantial percentage (29%) of editorial board members in spine journals have a potential conflict of interest, which is, as said, probably an underestimation since we were only able to trace about half of all editorial board members. This finding confirms that potential conflicts of interest exist within editorial boards which might subsequently influence the peer review process and may result in bias, potentially leading to altered conclusions or outright rejection of submitted manuscripts. Academia and medical journals in particular should be aware of this potential bias and strive to improve transparency of the review process. We therefore emphasize the following recommendations as proposed by the COPE, WAME, ICMJE, CSE, and AMA , 50, 51.These committees recommend that: (1) medical journals should have explicit conflict of interest policies for their editorial board and reviewers, which should be available online, and (2) medical journals should publicly report current and past relationships of editors and reviewers that could lead to conflicts of interest, including the type of relationship , dollar amounts, to give readers the opportunity to appreciate the results bearing in mind the disclosures of the editors and reviewers involved in the review process –46, 49. Importantly, one should be aware that disclosure is not a panacea: it may result in a situation that puts more weight on the biased information . When anJournals should have explicit conflict of interest policies for editorial board members and reviewers, which should be available onlinePotential conflicts of interest of individuals involved in the editorial and review process should be reportedA regularly updated database including disclosures of editors and reviewers should be publishedJournals should aim to minimize bias in the review process. This can be facilitated by: (1) the introduction of “Evidence and Methods” deputy editors with no relationships to device or pharmaceutical companies, reviewing the methodological rigor and proper reporting of error and potential bias, (2) preclusion of conflicted peer reviewers and editors where possible