Recent evidence shows a novel role for eye vergence in orienting attention in adult subjects. Here we investigated whether such modulation in eye vergence by attention is present in children and whether it is altered in children with ADHD compared to control subjects. We therefore measured the angle of eye vergence in children previously diagnosed with ADHD while performing a cue task and compared the results to those from age-matched controls. We observed a strong modulation in the angle of vergence in the control group and a weak modulation in the ADHD group. In addition, in the control group the modulation in eye vergence was different between the informative cue and uninformative cue condition. This difference was less noticeable in the ADHD group. Our study supports the observation of deficient binocular vision in ADHD children. We argue that the observed disruption in vergence modulation in ADHD children is manifest of altered cognitive processing of sensory information. Our work may provide new insights into attention disorders, like ADHD. Attention deficit hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders affecting an estimated 3 to 7% of school-aged children worldwide. It is characterized by a low degree of attention, a high degree of hyperactivity and impulsivity, and the inability to inhibit inappropriate actions.Several studies show that subjects with attention disorders like ADHD show atypical oculomotor behavior. In particular, compared to controls ADHD patients show an increased variability of saccadic responses ,2. IncreVergence refers to the simultaneous movement of both eyes in opposite directions to obtain single binocular vision . PreciseRecently we found a relationship between eye vergence and orienting visuospatial attention in human adults . We obseHere we tested whether attention-related eye vergence also occurs in children. As poor binocular coordination in children is linked to ADHD  we also Twenty-nine children diagnosed with ADHD, aged between 7 and 14 years , and a similar number (thirty-five) of sex/age matched healthy children participated in the experiment. Children with ADHD were classified as type Combined (N = 10), as Inattentive (N = 4) or as Hyperactive (N = 15). Twenty participants of the ADHD group were taking stimulant medication (Methylphenidate). The ADHD diagnosed children were all recruited through the Child and Adolescent Health Mental Center from Consorci Sanitari del Mareme, a public health consortium in Maresme (a nearly 400.000 inhabitant’s area in the North of Barcelona). Cases were diagnosed using the American Psychiatric Association's Diagnostic and Statistical Manual-IV-Text Revision criteria including a psychiatric and psychologist interview to assess the presence of symptoms of in-attention, hyperactivity and impulsivity during the last 6 months. Also the beginning of the symptoms before 7 years of age and the persistence of clinical dysfunction in at least two settings (school and home) were used as criteria . ReasonsThe children were given detailed instructions for the experiments. Before participating in the study written informed consent from the parents on behalf of the children enrolled in our study was obtained in accordance with the Helsinki Declaration. The study was approved by the Ethics Committee of the University of Barcelona and of Consorci Sanitari del Maresme.We used EventIDE  for presenting the visual stimuli. The display resolution was 1024 x 768 pixels. The participants’ position of gaze was monitored using a binocular remote eye-tracking system at a sample rate of 120 Hz .Participants sat in a dimly lit room of the hospital or schools, in front of the PC monitor at a distance of 40–60 cm. To have similar conditions lights were switched off and curtains closed. The eye tracker was positioned in such a way that ambient lighting did not affect the recordings. The eye tracking equipment was calibrated  for each participant at the beginning of the experiment. Gaze fixations of at least 1000 ms within a region of 2°-3° around each calibration point were considered accurate. As subject needed only to fixate centrally during the task, mapping gaze position was secondary. Before starting the task, all participants practiced with some cue and no-cue trials  to become familiar with the task. In both groups (ADHD and control) a similar number of practice trials were offered. When they confirmed that they understood the task we ran the experiment.To assess orienting visual attention we used a paradigm in which participants were required to discriminate the emotion (happy/sad) of a cartoon face placed in the periphery. During the task children had to maintain fixation at a central cross. On half of the trials participants were informed of the location of the face stimulus by a central cue stimulus (informative cue condition). On the other half they were unaware of the target location (uninformative cue condition).The experiment  consisteAfter 1000 ms, an informative cue stimulus or an uninformative cue stimulus appeared on top of the fixation cross. In both tasks the informative cue was an arrowhead with a size of 0.32° or 0.35° for 2 and 4 faces, respectively. The uninformative cue stimulus was a central cross with a size of 1.4°x1.4°. The informative cue was always valid. After an additional period of 1000 ms, one of the peripheral faces changed into a happy or sad face  into angular units through algorithms designed to calculate 3-D components  of both eye gaze vectors. Sx,y,z are the three coordinates which represent the intersection point of the lines describing the line of sight of each eye. When these lines do not intersect this represents the midpoint of the smallest distance between them. The transformation was performed using a distance of the screen to the observer (DSD) of 50 cm and 5.5 cm for the inter-pupil distance (IPD). The angle of vergence is the angle at which the intersection of both eye gaze vectors made the least error. Sx,y,z are calculated as follow:We calculated the angle of vergence by transforming the eye recordings  cue and 1002 (47%) no-cue trials in the control group and 723 (46%) cue and 829 (53%) no-cue trials in the ADHD group. From the eye position data, saccades were detected by using a vector velocity threshold of approximately 200 degrees per second. For statistical analysis t-tests and a multi-comparison ANOVA test were used.28 = 1.40, p = 0.17; uninformative cue condition: t-test28 = 1.88, p = 0.07) to the detection performance of the control group . No significant difference in detection performance  and reaction time  was observed between the 2 and 4 faces condition. Neither differences between informative cue and uninformative cue conditions in detection performance were observed . The behavioral reaction times of the informative cue trials and uninformative cue trials  were different . No differences in reaction times were observed between the control and ADHD group .Average detection performance of the ADHD group  was similar  in the ADHD group.To determine whether there is a difference between the control group and ADHD group in eye vergence, we calculated the average size of the angle of vergence across both conditions (cue and no-cue) within the first 100ms after cue stimulus presentation as an indication of initial vergence angle and compared the values to the ones obtained from the final 100ms window of analysis, i.e. 900-1000ms after target presentation  = 31.5, p<10−7). In particular the mean angle of vergence in the uninformative cue condition of the control group was smaller than the mean angle of vergence in the uninformative cue condition of the ADHD group  = 68.0, p<10−11;  = 19.3; p<10−5). In the ADHD group no difference in the mean angle of vergence between the informative cue and uninformative cue condition was observed  = 0.50; p = 0.47). We did not find a difference in vergence modulation between 2 face and 4 face tasks  vergence angles at the start of the trial, which suggests no asymmetry in the direction of fixation disparity between Control and ADHD subjects.Children tend to have crossed disparity when fixation words , which mPreviously we demonstrated in adults that the angle of eye vergence changes during orienting visual attention . In thisCompared to our first study in adults  the diffWe believe that eye vergence during gaze fixation is involved in orienting visuospatial attention . This idThe role of the proposed attention related vergence is unknown but we propose  that theDespite the difference in attention related vergence, in this study we did not find significant differences in behavior between the control and ADHD groups, although the ADHD group performed slightly worse on the task. Also, ADHD subjects responded faster in the informative cue condition than in the uninformative cue condition showing the behavioral improvement by attention. This seems at odds with the disruption of modulation of attention related eye vergence. This discrepancy can be accounted for by more variation in the ADHD subjects leading to a lack of significant difference between the different conditions. Large response variation is typically observed in ADHD patients and may lead to inconsistent findings in covert attention paradigms . AlternaConvergence insufficiency (CI) is a common binocular disorder characterized by the inability to obtain a single visual field while working at a near distance –38. The Top down attention originates in the frontal cortex ,44 and rOcular dominance columns in the visual cortex are formed during early ontogenetic stages and can be modified after birth during the sensitive period. Recent evidence shows that ocular dominance maps may serve as a scaffold for the formation of disparity maps . DispariOur observations show that attention related vergence differs between controls and children with ADHD. This finding points to the possibility that evaluation of vergence during an attention task may be useful for the development of an observer independent tool for the diagnosis of ADHD. Furthermore, for people with binocular deficits, vision therapy increases the eyes' convergence ability with eye-focusing exercises. Typically, these exercises include simple ‘pencil pushups’, computer vision therapy, or glasses with built-in prisms. It will be interesting to examine whether attention related vergence can be improved by vision therapy that employs purposed designed visual tests.This is the first study assessing attention related vergence in children with ADHD. The study used a limited number of subjects and children were recruited differently; ADHD patients from a hospital and controls from a public school. Although the ADHD group was sex/age matched with peers, recruiting children differently may have introduced a discrepancy in educational and social level between both groups resulting in a difference in attention-related vergence. Moreover, children were tested in different rooms that may have different lighting condition and may affect the quality of the eye recording data, although lightning conditions were kept similar as possible. If our results were attributed to differences in lightning conditions, we would have seen global differences in the recordings and not in a specific stimulus locked window. Moreover the calibrations qualities were similar in both conditions indicating that differences in noise level in eye position data cannot explain the observed difference in eye vergence . The outOur study supports the observation of deficient binocular vision in ADHD patients. We argue that the observed disruption in vergence eye modulation in children with ADHD is manifest of a deficient cognitive processing of sensory information. Our work may provide new insights into the neurobiology of ADHD, and may be the start of developing new and complementary tools for probing ADHD. Further studies are needed to resolve a possible role of eye vergence in visual cognition.


Microorganisms in unamended, warm (63°C) and geochemically altered anoxic fluids taken from 292 meters sub-basement (msb) near the Juan de Fuca Ridge produced 267.3 mJ of heat over the course of 97 h during a step-wise isothermal scan from 35.5 to 85.0°C. Most of this heat signal likely stems from the germination of thermophilic endospores (6.66 × 104 cells ml-1FLUID) and their subsequent metabolic activity at temperatures greater than 50°C. The average cellular energy consumption (5.68 pW cell-1) reveals the high metabolic potential of a dormant community transported by fluids circulating through the ocean crust. By contrast, samples taken from 293 msb from cooler (3.8°C), relatively unaltered oxic fluids, produced 12.8 mJ of heat over the course of 14 h as temperature ramped from 34.8 to 43.0°C. Corresponding cell-specific energy turnover rates (0.18 pW cell-1) were converted to oxygen uptake rates of 24.5 nmol O2 ml-1FLUID d-1, validating previous model predictions of microbial activity in this environment. Given that the investigated fluids are characteristic of expansive areas of the upper oceanic crust, the measured metabolic heat rates can be used to constrain boundaries of habitability and microbial activity in the oceanic crust.Although fluids within the upper oceanic basaltic crust harbor a substantial fraction of the total prokaryotic cells on Earth, the energy needs of this microbial population are unknown. In this study, a nanocalorimeter (sensitivity down to 1.2 nW ml Low to moderate temperature (<100°C) fluids circulating within the uppermost basaltic ocean crust are known for their contribution to global biogeochemical cycling , and forThe physiological state of microbial communities in low-energy systems is manifestly different than those observed in laboratory cultures, which are characterized by rapid growth, high metabolic rates, and high cell densities . NaturalAn alternative approach to determining the metabolic rate of microorganisms in low-energy settings is to measure the energy dissipated by all biological activities using direct calorimetry . This apCalorimetry is based on the assumption that heat is the direct product of all metabolic functions . Calorimin situ physicochemical conditions. Warm (>60°C) anoxic fluids are common in all ocean basins , which may be more informative ecologically to constrain the global rates of microbial activity in deep basaltic ocean crust.In this study, we measured the change in enthalpy as a function of temperature by direct nanocalorimetry in order to quantify and interpret microbial energy requirements in natural subseafloor igneous crustal fluids from two aquifers that differ with respect to their n basins ; howevern basins  and presn basins . TherefoJason II deployed from the R/V Atlantis (cruise AT 26-18). NP crustal fluids were sampled in April of 2012 from a CORK observatory at Hole U1383C  using the ROV Jason II (WHOI) deployed from the R/V Maria S. Merian (cruise MSM 20-5). Both boreholes (U1362A and U1383C) are instrumented with multilevel CORK observatories . The CORK observatory at borehole U1362A (JFR) is situated at 2661 m below sea level, penetrating 236 m of sediment and the upper 292 m of basement. The CORK observatory at borehole U1383C (NP) is located at 4425 m below sea level and penetrates the upper 293 m of basement through 38 m of sediment. Samples from the deepest horizons were collected at the seafloor into sampling bags of Tedlar polyvinyl fluoride (PVF) film  as previously described  observatories installed within boreholes drilled several hundred meters into the ocean crust, preventing circulation between the open hole and ocean bottom water and allowing access to deep crustal fluids. Samples from the eastern flank of the JFR were obtained in August 2014 from a CORK observatory at borehole U1362A  using the ROV vatories , which aescribed  and retuTable 1. Additional original data, including analytical methods, are published elsewhere  and characterized by a steep chemical gradient; the dominant oxidant changes from oxygen to sulfate, which is accompanied by a decrease in organic matter concentration and an increase in the reduced species hydrogen sulfide and methane . Crustallsewhere .Metabolic heat production rates in crustal fluids were measured using a thermal activity monitor model TAM III equipped with a nanocalorimeter . The TAM III coupled to the nanocalorimeter offers the maximum sensitivity of most commercial isothermal calorimeters . These m-1) was used. Thermal equilibrium is not always achieved when differential scanning calorimetry data are collected using far higher scanning rates . These temperature ranges extend beyond the upper and lower limits of observed microbial activity. To ensure that the samples were in thermal equilibrium with the calorimeter and that the collected data corresponded to that at the true transition temperatures, a very slow scan rate , crimped and sealed with butyl rubber stoppers. To prevent contamination of the JFR flank anoxic fluids with oxygen, the ampules were prepared in an anaerobic chamber . The reference ampule consisted of 2 ml filter-sterilized (0.2 μm) crustal fluids and 2 ml of headspace. Sample and reference ampules were prepared at the same time  and pre-incubated in the calorimeter at the operating temperature for 24 h prior to each experiment. This minimized potential changes in heat flow associated with, for example, differences in temperature between sample and nanocalorimeter and stresses related to sample preparation.Two independent nanocalorimeters were used simultaneously to run parallel blank experiments, which consisted of 0.2 μm filter-sterilized crustal fluids in both the sample and reference ampules. An initial baseline correction was done by subtracting the blanks from the sample heat-flow profiles. After identification of upper and lower temperatures of measurable metabolic heat rates, a second baseline correction was drawn manually between these temperatures using the TAM III Lab Assistant Software  to obtain final data on microbial activity.Endosporulation allows certain bacteria to persist as dormant cells in adverse conditions, such as prolonged exposure to the low (4°C) storage temperatures . In ordep-phenylenediamine anti-fade mounting medium and visualized using a Nikon Eclipse Ti-E inverted microscope  equipped with a drift correction unit (Nikon Perfect Focus System) for maintaining focus at the coverslip-filter interface during imaging. Fluorescence imaging of SYBR Green I was done in the FITC (Nikon filter set B-2E/C). At least 1000 cells stained with SYBR Green I were counted per sample using the scientific image analysis and visualization program DAIME  of organic matter oxidation with the dominant available terminal electron acceptor (SO42- for JFR and O2 for NP) were calculated as a function of temperature for the reactionsEnthalpies . Proline (C5H9NO2) was used as a proxy for organic matter since its nominal carbon oxidation state  as watts of heat flow. The watt unit is defined as the energy consumption rate of one joule per second. Standard deviation of initial and final isothermal measurements provided an estimate of baseline reproducibility of 2.7 nW ml-1 and 1.2 nW ml-1 in fluids from the JFR flank and NP, respectively. These data were used to determine the detection limit of microbial metabolic heat production rates on crustal fluids and to delimit the minimum temperature (Tmin) and maximum temperature (Tmax) of activity, which were established as 36–85°C in JFR flank fluids and at 34–43°C in NP fluids. The resulting values of ΔHr for Reaction (1) were -12.7 to -13.7 kJ (mol SO42-)-1 from 36 to 85°C, those for Reaction (2) were -444 to -447 kJ (mol O2)-1 from 34 to 43°C, while those for Reaction (3) were -371 to -373 kJ (mol O2)-1 from 34 to 43°C.Metabolic heat production rates were measured in crustal fluids by two-step isothermal nanocalorimetry . Maximum heat production rates of 1.27 μW were determined at a temperature optimum (Topt) of 73.5°C in JFR flank fluids, while 0.57 μW were measured at Topt 38°C in NP fluids. Both of these values are ∼15°C above their respective in situ temperatures.During the transition between initial and final isothermal measurements, metabolic heat production rates increased through a maximum, followed by a continuous decrease . Taking into consideration the potential contribution of germinating cells to the measured metabolic heat rates, the cell-specific energy turnover rate in JFR fluids was estimated at 5.68 pW cell-1 (Table 2). No germinating cells were detected in NP fluids and the cell-specific energy turnover rate was estimated at 0.18 pW cell-1 (Table 2).The energy turnover per cell was calculated by dividing the total heat produced during the course of the nanocalorimetry experiment by the number of cells in each fluid sample. Integration of the heat flow temperature plots showed that 267.3 mJ were produced by microbial metabolism in JFR fluids and 12.8 mJ were produced in NP fluids, over 97 and 14 h, respectively. Cellular enumeration within crustal fluids from the JFR flank and NP revealed concentrations of 8.67 × 10Figure 2 is the sum of the enthalpies of all of the reactions catalyzed by microorganisms. These heat signals can be combined with computed enthalpies of reactions that are thought to be catalyzed by microorganisms in situ to infer rates of metabolic activity. The amount of heat detected in fluids taken from the subseafloor at the JFR flank and at NP differ considerably , indicating different underlying processes.The rate of heat production measured in the nanocalorimeter is equivalent to the heat produced by the sum of all of the reactions occurring in the sample chamber. Essentially, the signal shown in Figure 2A are at least partially due to the enthalpy of this process. However, using the range of ΔHr values calculated for Reaction (1) and assuming that the total amount of heat measured in the JFR flank sample, 267.3 mJ, was due to sulfate-reduction, the corresponding rates would be 2.4–2.6 × 103 nmol-1 ml-1FLUID d-1, far greater than the gross rates of sulfate reduction previously measured in JFR fluids, ∼0.01 nmol ml-1FLUID d-1 (4 cells ml-1FLUID). In fact, thermophilic spore-forming bacteria, including close relatives to members of the sulfate-reducing Firmicutes phylum and Candidatus Desulforudis lineage, have been reported from these fluids  show oxygen respiration rates of 24.5 nmol O2 ml-1FLUID d-1. Furthermore, other metabolic processes, i.e., nitrification, which describes the oxidation of NH4+ to ultimately NO3-, could also influence oxygen dynamics in NP fluids , the increase in oxygen respiration due to nitrification would yield rates of 29.3 nmol O2 ml-1FLUID d-1. Altogether, these rates validate previous model predictions of microbial activity  and compiled cell-specific respiratory rates for anaerobic and aerobic microbes in other deep subsurface environments, ∼3 × 10-3to-8 pW cell-1 and ∼1 × 10-1to-8 pW cell-1, respectively (It should be noted that when activities of natural populations of bacteria are estimated in terms of sulfate reduction or oxygen consumption, only the energy turnover of respiration is calculated, but there are also energetic costs—and thus heat signals—associated with other cellular processes such as anabolism. In the case of microorganisms in energy-limited environments, anabolic activity is mostly associated with the energy demand for the repair of accumulated damage to key macromolecules, i.e., DNA and housekeeping proteins , the eneectively , could pectively . MeasureAR designed and performed experiments, analyzed data, and wrote the paper. AR performed and analyzed calorimetry data. DL contributed to the analysis of calorimetry data, performed thermodynamic calculations, and contributed to the preparation of the manuscript. SJ, H-TL, and MR were instrumental in the acquisition of fluid samples. AR and JA conceived the study, and JA and KN supported the study. All authors discussed the results and implications and commented on the manuscript at all stages.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Obsessive compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD) are two of the most common neuropsychiatric diseases in paediatric populations. The high comorbidity of ADHD and OCD with each other, especially of ADHD in paediatric OCD, is well described. OCD and ADHD often follow a chronic course with persistent rates of at least 40–50 %. Family studies showed high heritability in ADHD and OCD, and some genetic findings showed similar variants for both disorders of the same pathogenetic mechanisms, whereas other genetic findings may differentiate between ADHD and OCD. Neuropsychological and neuroimaging studies suggest that partly similar executive functions are affected in both disorders. The deficits in the corresponding brain networks may be responsible for the perseverative, compulsive symptoms in OCD but also for the disinhibited and impulsive symptoms characterizing ADHD. This article reviews the current literature of neuroimaging, neurochemical circuitry, neuropsychological and genetic findings considering similarities as well as differences between OCD and ADHD. Obsessive compulsive disorders (OCD) are typically characterized by the presence of recurrent, intrusive, and disturbing thoughts (obsessions) which often elicit anxiety or emotional stress followed by repetitive stereotypic behaviour or thoughts (compulsions) in order to neutralize the negative affects  is characterized by a persistent pattern of inattention and/or hyperactivity and impulsivity  with a following contrast made by the authors of the present review. Some of the results showed shared aetiological factors and mechanisms for both disorders, whereas other findings differentiated between ADHD and OCD. The aim of this overview is to help to understand the aetiology of psychiatric disorders, in particular concerning ADHD and OCD.A major aim in recent years has been to shed light on the relationship between clinical symptoms of ADHD and OCD and the underlying brain structure, function, and connectivity. Extensive neuroimaging literature exists on the comparison of either disorders with matched healthy controls, and a variety of methods have been used to assess brain structure, metabolism, and the spatial and temporal organization of brain networks. The timing of information processing is commonly studied with brain imaging methods that exhibit a high temporal resolution in millisecond time range, such as electroencephalography (EEG) or alternatively by magnetoencephalography. Details about brain structure and the spatial activation pattern are best assessed by  magnetic resonance imaging or positron emission tomography (PET). Here, we summarize the most consistent abnormalities found in brain structure and functional activation patterns revealed by structural magnetic resonance imaging, functional magnetic resonance imaging (fMRI), and event-related potentials (ERP) studies for both ADHD and OCD. We focused on similarities and differences of affected brain regions reported across these patient groups and specifically point to meta-analytic studies and their findings. Concluding this section, we summarize the results of the only study that directly compared functional neuroimaging data of paediatric patients with ADHD to patients with OCD   circuit function in ADHD and OCD patients  negativity after 200–300 ms and a later (350–600 ms) fronto-central P3 (or P300) positivity. These ERPs have usually been studied with STOP and Go/Nogo tasks  and OCD (g = 0.77), reflecting the diminished speed of the inhibitory process. In a recent study comparing adults with ADHD and OCD, Abramovitch et al. , norepinephrine transporter (NET), and serotonin transporter (SERT) knockout mice. These observations by Gallagher et al.  and monoamine-oxidase-A (MAO-A) demonstrates polymorphisms in both these genes in males as shown by a meta-analysis by Taylor , female OCD patients had a significantly reduced concentration of glutamate–glutamine in subareas of the ACC. In addition, male and female OCD patients had higher concentrations of myoinositol-containing compounds in their right rostral and dorsal ACC  approached efficacy in OCD patients  studies of OCD have been published so far  or polymorphism has been found to be affected in ADHD  between responders and non-responders to citalopram with quetiapine. However, OCD patients with the Met/Met genotype (48 %) of the COMT polymorphisms showed a treatment response to 10-week citalopram in drug-free/drug-naive OCD patients  Met allele reduces COMT enzyme activity and is associated with impulsiveness and substance abuse in ADHD, Soeiro-De-Souza et al.  DAT1 polymorphism had additive effects on 11C-altropane DAT binding  polymorphisms are associated with activity–impulsivity-related traits in dogs  and the disorder  are essential in modulating behaviour. The high risk of D2, D4, and D5 receptor polymorphisms in ADHD has been reviewed by Wu et al. . DisruptIn conclusion, it seems that dopamine-related genes are much more associated with ADHD than with OCD /deletion  polymorphism. In comparison with the S-allele, the L-allele has been reported to exert an increased transcriptional activity and an increased basal re-uptake of 5-HT in vitro   with OCD was confirmed by a meta-analysis , the rate-limiting enzyme in 5-HT synthesis in the brain, that was studied for the first time for its association in early-onset OCD , although some genes seem to be unique to one disorder .In conclusion, it seems that the serotonin-related genes have some common gene associated with OCD and ADHD (e.g. NET), this gene and related genes have been studied. Yet, only the dopamine beta hydroxylase (DBH), the enzyme that synthesizes norepinephrine from dopamine, was found to be associated with ADHD after a meta-analysis  in ADHD is the norepinephrine transporter (SLC1A1) gene on 9p24 is one of the few candidate genes for OCD that was investigated due to its localization within a linkage peak by Hanna et al. (SLC1A1/EAAC1 (excitatory amino-acid transporter 1) mRNAs, P2, ex2skip, and ex11skip  nor were any associated with OCD. These authors, however, found that rs4740788 was associated with OCD in all families and in families with affected males. A three-SNP haplotype (rs4740788–rs10491734–rs10491733) was associated with OCD in the total sample  at 9p24 , cadherin 13 H-cadherin (CDH13), and catenin (cadherin-associated protein) alpha-2 (CTNNA2) but also others  and serotonin (OCD). Fronto-striatal- and orbito-frontal circuitries reflect significant differences from a morphological and neurochemical point of view. The ACC and MPFC have recently received major interest especially in OCD. The molecular genetic findings correspond well to the neurochemical and imaging perspective. Linkage studies show for ADHD, regions of significant linkage on chromosome 16q, containing the


Landraces are an important source of genetic diversity in common wheat, but archival collections of Afghan wheat landraces remain poorly characterised. The recent development of array based marker systems, particularly single nucleotide polymorphism (SNP) markers, provide an excellent tool for examining the genetic diversity of local populations. Here we used SNP analysis to demonstrate the importance of Afghan wheat landraces and found tremendous genetic diversity and province-specific characteristics unique to this geographic region.A total of 446 Afghan wheat landraces were analysed using genotype by sequencing (GBS) arrays containing ~10 K unique markers. Pair-wise genetic distance analyses revealed significant genetic distances between landraces, particularly among those collected from distanced provinces. From these analyses, we were able to divide the landraces into 14 major classes, with the greatest degree of diversity evident among landraces isolated from Badakhshan province. Population-based analyses revealed an additional 15 sub-populations within our germplasm, and significant correlations were evident in both the provincial and botanical varieties. Genetic distance analysis was used to identify differences among provinces, with the strongest correlations seen between landraces from Herat and Ghor province, followed closely by those between Badakhshan and Takhar provinces. This result closely resembles existing agro-climatic zones within Afghanistan, as well as the wheat varieties commonly cultivated within these regions. Molecular variance analysis showed a higher proportion of intra-province variation among landraces compared with variation among all landraces as a whole.The SNP analyses presented here highlight the importance and genetic diversity of Afghan wheat landraces. Furthermore, these data strongly refute a previous analysis that suggested low genetic diverse within this germplasm. Ongoing analyses include phenotypic characterisation of these landraces to identify functional traits associated with individual genotypes. Taken together, these analyses can be used to help improve wheat cultivation in Afghanistan, while providing insights into the evolution and selective pressures underlying these distinct landraces.The online version of this article (doi:10.1186/s12870-014-0320-5) contains supplementary material, which is available to authorized users. Triticum aestivum) is the third most important cereal crop worldwide in terms of production and the most important in terms of calorie consumption, with overall production increasing year after year [Wheat , chickpeas (Cicer arietinum), peas (Pisum sativum), and rye . However, frequent armed conflicts and other factors have led this country to lose all known germplasm collections developed to date. Fortunately, one long-running scientific expedition led by Dr. Hitoshi Kihara and others between 1950 and 1970 established an extensive Afghan wheat landraces collection, which is now housed in Japan. While other Afghan wheat collections do exist, the collection of landraces found in the Kihara Institute for Biological Research, Japan is thought to be unique in terms of the number of sites visited, the diversity of their environmental conditions, and the overall number of landraces collected [Afghanistan is the third largest centre of origin for domesticated crops worldwide , having ollected . MoreoveThe recent development of molecular markers and high throughput systems has revealed a wealth of genotypic information for a wide variety of crops and plants ,6. AmongAlthough the importance of landraces in terms of both conservation and utilisation remain controversial , much ofcompactum (Alef.) Velican to var. speltoides (Alef.) Velican  . The majHigh-throughput SNP arrays were used to evaluate 446 KAWLR samples and 45 controls originating from landraces of neighbouring countries, along with improved Afghan varieties, and one durum wheat genotype. Phylogenetic analysis revealed the complex nature of the diversity present in these landraces, which could be divided into 14 major clades Figure . Among tClade VII contained the Iranian landraces NBRP47 and NBRP105, along with most of the Herat and Kandahar landraces, and an additional 11 landraces from Ghor. Geographically speaking, Ghor province is located in the centre of Afghanistan and is surrounded by the provinces of Herat, Wardak, Badghis, Kandahar, and Bamyan; this central location likely accounts for the overlap among these regions. Clades III, IV, and XI included a mixture of Afghan landraces belonging to different provinces, along with control NBRP48, which clustered in clade IV.The remaining controls were grouped mainly into three clades: V, XII and XIV, of which clade V was comprised exclusively of controls. The rest of the hexaploid wheat controls, accounting for 30 genotypes, clustered within clades XII and XIV alongside 23 Afghan landraces , consisting of 10 from Badakhshan, five from Kabul, two from Takhar, one from Kunduz, one from Ghor, one from Herat, and three from unknown sources. The significant divergence between the Afghan landraces and controls highlights the novelty of this collection and its potential value for the development of new wheat varieties.Triticum durum Desf.), a distinction most likely the result of misclassification or human error.As expected, the durum wheat genotype was clustered as an out-group in this analysis, although four Afghan landraces also clustered independently of other landraces in the highly differentiated clade XIII. Table milturum (Alef.) Velican from Badakhshan province was grouped exclusively with landraces collected from high elevations. Other examples include var. ferrugineum (Alef.) Velican and var. erythrospermum (Alef.) Velican, the major varieties found in our collection, which were often grouped together. Overall these results highlight the considerable diversity present in our germplasm, along with the ability of STRUCTURE analysis to better connect genomic diversity with its corresponding phenotypic outcomes, such as geographic distribution and botanical varieties.To further clarify our diversity analysis and to better estimate population subdivisions, a population structure analysis was performed using only KAWLR samples. Samples were analysed using STRUCTURE software , revealiThe Badakhshan samples contained the greatest degree of diversity in our study, which can be used to adapt existing wheat strains to particular agro-climatic zones. Afghanistan is divided into eight agro-climatic zones , each ofOutside of botanical varieties, population structures were also affected strongly by the collection year. For instance, genotypes collected before 1979 were classified either primarily or completely within sub-populations 2–5, 8–11, and 14, whereas samples collected in 1979 or later grouped primarily in sub-populations 1, 6, 7, 12, 13, and 15. Moreover, landraces collected before 1979 were distributed across a higher number of sub-populations, with an average major sub-population contribution of 77.6%, compared with 84.7% for landraces collected after 1979. This analysis indicates a shift towards lower overall genetic diversity over time, with less deviation from a landrace’s major sub-population. This observation is consistent with our original assumptions, in that increasing wheat cultivation during this time period led to a reduction in overall genetic variation due to the greater availability and deployment of improved varieties, along with substantial changes in living conditions. Similar trends have continued in the years since this collection was completed, highlighting the need for alternative approaches to wheat cultivation in this region .Next, landrace population structures were re-estimated using only 385 landraces collected from Badakhshan, Ghor, Herat, Takhar, Kabul, Badghis, Kandahar, Bamyan, and Samangan provinces, resulting in 10 distinct sub-populations. The strongest divisions were seen among landraces isolated from Badakhshan and Takhar provinces, as these two regions grouped independently of the remaining regions when divided into two groups  was performed under different conditions Table . The resThis is the first study demonstrating the untapped genetic potential of Dr. Kihara’s Afghan wheat landrace collection. This study was performed using the maximum number of markers available, revealing a substantial degree of genetic diversity among samples. This work also disproved a previous study that evaluated this germplasm and suggested a low degree of overall diversity . Our useThe main source of material used in this study was from the KAWLR collection, which represents a series of Afghan wheat landraces collected from 1950–70 via a variety of scientific expeditions. This collection has been preserved and maintained under the auspices of the National Bio-Resources Project, Japan. A portion of this collection representing 446 unique accessions was selected for use in this study  1.0 V arrays . SNP markers with a minor allele frequency >10% and markers with >80% good data were selected for further analysis. As the populations represented by this collection are presumed to be homozygous in nature, they were maintained in a controlled pollination environment. Replicates taken from the same landrace that exhibited similar botanical variety phenotypes were considered the same. Genotyping was performed using only a single plant from each landrace. Sequence alignments and SNP extractions were performed using Triticarte software; only SNPs with a call rate >90% were considered. Chromosomal mapping of SNP markers was performed in another recombinant inbred line population (unpublished data) using a Statistical Machine Leaning methodology (Triticarte) .t test. Principal coordinate analysis (PCA) was conducted on the basis of genetic similarity using the EIGEN procedure in GeneAlEx 6.4 [Genetic diversity analysis was performed using DARwin software  and the AlEx 6.4  to obserAlEx 6.4 . This alAlEx 6.4 .A Bayesian-clustering program utilising a Markov Chain Monte Carlo (MCMC) approach, STRUCTURE version 2.3.4 , was use


The World Health Organisation recommends that each country adopts its own cut-off value of low birth weight (LBW) for clinical use. The aims of this study were to establish a clinical cut-off point for LBW and to determine its incidence, predictors and complications in a sub-urban area’s hospital of Cameroon.We conducted a study in two phases: a 6-year retrospective phase during which we collected demographic and clinical information from the records of the maternity of the Buea Regional Hospital (BRH) and a 3-month prospective phase during which data were collected from consenting pregnant women using a structured questionnaire, and newborns were examined and followed after birth.th centile of birth weights was 2600 g. In the 200 pregnant women enrolled during the prospective phase, using this cut-off yielded an incidence of LBW of 19.0 %. Independent predictors of LBW were preterm delivery, hypertensive disorders in pregnancy, HIV infection, maternal age >36 years, maternal height <150 cm and pre-delivery BMI < 25 kg/m2. Neonates with LBW were more likely to have neonatal asphyxia, foetal distress, respiratory distress and neonatal death.A total of 4941 records were reviewed during the retrospective phase and the 10Our results suggest that newborns under 2600 g have LBW in sub-urban Cameroon. They represent one out of every five babies, and they deserve close care. Preventive measures targeting the predictors described here are warranted to reduce the incidence and complications. Similar studies in urban areas are required in order to generalize the results. LBW is estation .th centile used to define LBW is usually set at 2500 g [The 10South Central Asia bears the highest burden of LBW infants – with about 27 % of all birth. The UNICEF/WHO estimates report an incidence of LBW of 11 % in Cameroon . This hiIn Cameroon, studies to define a cut-off value that can be used for clinical care have not yet been carried out to the best of our knowledge. In this study we sought to determine the clinical cut-off value for LBW in a sub-urban area’s hospital. We also assessed the incidence, predictors and complications of LBW.We carried out a descriptive and analytic study with two phases at the Buea Regional Hospital (BRH): a retrospective register analysis used to determine the cut-off of LBW in our population, and a prospective phase used to assess the incidence, predictors and complications of LBW.The BRH is situated in the Buea Health District (BHD) which is part of the Fako Division, South-West Region, Cameroon. The BRH acts as the reference hospital in the health district and also performs more deliveries than all the other health facilities in the district. The hospital has all standard units of general medicine. One gynaecologist-obstetrician and one paediatrician run the maternity and the paediatric units respectively. The institution lacks a neonatal intensive care unit; also, the maternity is situated 114 m apart from the operating rooms (where oxygen is kept). This distance represents a pitfall whenever a newborn requires oxygen.st January 2007 to the 31st December 2012 were reviewed. Only the records that clearly stated a gestational age less than 28 completed weeks, reported multiple gestation or had incomplete information were excluded  and low (none and primary).Obstetric history  history for the current pregnancy, and history of anaemia, fever, malaria and urinary tract infections during the current pregnancy.Past medical history .Toxicological history .Participants’ hospital records were used to extract information on the followingCamry bathroom scale-, height -to the nearest cm using a locally made stadiometer calibrated to the Butterfly brand measuring tape- were measured, and a standard physical examination was performed. Throughout the labour, the foetus was monitored for the presence of acute foetal distress .Participants’ weight -to the nearest kg using a Holtex + digital baby scale. The newborns were monitored for the presence of respiratory distress which was identified by the presence of any one of the following: respiratory grunting, nasal flaring, intercostal recessions, sub-xyphoid recession, thoraco-abdominal asynchrony, and respiratory rate < 40 or > 60 breaths per minute. All stillbirths and any in-hospital neonatal death was noted.After delivery, the neonates were assessed for viability , and their APGAR scores at the first, fifth and tenth minutes were determined. The baby’s weight was measured to the nearest gram using a The mother was then approached and informed of the entire study and her consent requested. Only those who agreed to participate in the study were included after they signed the inform consent form. Minors and their guardians signed assent and guardian consent forms respectively. The newborns and their mothers were observed until the day of discharge. This was usually a period of 3 days for normal deliveries and could extend to 10 days for complicated deliveries including caesarean sections and instrumental deliveries. Two hundred participants were enrolled during this prospective phase.Data were cross-checked for errors before entry into a password-protected personal computer. The data were stored securely in a private location and kept confidential. Participants were referred to only by identification numbers. Identifiable information (consent forms) was kept separate from the data collection forms and it was only possible to link both through a coding sheet which was available solely to the principal investigator.Epi Info version 3.5.4 and Microsoft Excel 2007. Means (standard deviations) were used to summarise continuous variables, and proportions and frequencies for categorical variables. Frequencies were compared using Fisher’s exact tests. The McNemar test was used to compare the incidence of LBW using the traditional cut-off (2500 g) to that yielded by our newly identified cut-off, and the agreement between the two was also computed. Predictors for LBW were determined using bivariate and multiple logistic regression models. The multivariate model included all variables which p-values in the bivariate analyses were less than or equal to 0.25 [Data were analysed using Ethical approval was obtained from the Institutional Review Board of the Faculty of Health Sciences, University of Buea. The study also received administrative clearance from the South-West Regional Delegation of Public Health and from the Director of the BRH.The mean age of the mothers was 26.4 ± 5.5 and 26.4 ± 5.8 years respectively for the retrospective and prospective phases of the study. Most were married, half were unemployed, almost all of them had received at least a primary level of education and 6.6 % of the women reported spending less than a USD (United States dollar) a day Table . None ofRegarding the obstetrical characteristics in the prospective phase Table , 34.5 % th centile of birth weight was 2600 g  (Table p = 0.03), maternal HIV infection (p = 0.02) and hypertensive disorders in pregnancy (p < 0.01) (Table 2 (p < 0.01)  Table ; obstetr Table ; Malaria or anaemia in pregnancy, gravidity ≥ 5, being a teenager, single marital status, alcohol consumption before or during pregnancy, a history of a previous LBW, being unemployed, maternal height < 150 cm, spending < 1USD a day and a low level of education were not associated with LBW Tables , 3 and 4p = 0.02), hypertensive disorders in pregnancy , maternal age > 36 years  and pre-delivery BMI < 25 kg/m2 .In multivariate analysis the following factors were independently associated with LBW: preterm delivery , maternal height < 150 cm , maternal HIV infection  and 10th minute (p = 0.03), foetal distress during labour (p = 0.01) and respiratory distress after birth (p < 0.01). They were also four times more likely to die within the early neonatal period (p < 0.01). We also observed that neonates who fell within the category >2500 g and ≤2600 g had significantly higher prevalence of complications compared with those > 2600 g (Table Neonates with LBW had a significantly higher risk of developing the following complications Table : neonatath centile of birth weight that defines the cut-off point for low birth weight (LBW) was 2600 g. In this sub-urban newborn population the clinical cut-off for LBW was therefore higher than the 2500 g traditionally used elsewhere. We are not aware of any study that has attempted to set the cut-off of LBW in Cameroon or elsewhere in sub-Saharan Africa. In developed countries, cut-off used in studies span from 2750 g in USA in the early 1990s [We found in our study that the 10Using 2500 g as the cut-off, the incidence of LBW was 13.5 %. A recent study in the same area yielded a similar result (13.7 %) . This in2 were independent predictors of LBW. The role of preterm delivery as a predictor of LBW is obvious because preterm babies have not thrived enough to reach their target term weight. These findings reinforce the relevance of appropriate prevention and care of pregnancy-associated comorbidities like HIV infection and hypertensive disorders to prevent LBW. They also emphasize the risk associated with advanced maternal age. Siza et al. in Tanzania also identified hypertensive disorders in pregnancy and HIV infection as factors associated with LBW [In multivariate analysis we found that preterm delivery, maternal height < 150 cm, maternal HIV infection, hypertensive disorders in pregnancy, maternal age > 36 years, and pre-delivery BMI < 25 kg/mwith LBW . The vicwith LBW  explains2 – a combination of maternal, fetal and amniotic fluid weights - highly suggest a pre-pregnancy undernutrition. Indeed, Lawoyin et al. previously reported that mothers who had LBW neonates had significantly lower BMI at the onset of pregnancy and gained significantly less weight in the third trimester and last four weeks of a term pregnancy [2 were more likely to have LBW neonates. In Tanzania pregnant women who had malnutrition (BMI <18 kg/m2) had the highest proportions of LBW neonates, followed by pregnant women who were undernourished (BMI from 18-22 kg/m2) [Women usually gain weight during pregnancy, and a pre-delivery BMI < 25 kg/mregnancy . This pron BMI <1 kg/m2 haThe association between maternal socio-economic status indicators such as low level of education or low incomes is controversial in developing countries. Some studies have reported an association with LBW , whereaset al. in Kenya had as leading complications of LBW: respiratory distress, apnoeic spells and sepsis [et al. in Douala reported LBW as the most common diagnosis associated with neonatal death [LBW neonates in our study were more prone to foetal distress, low APGAR scores at delivery and respiratory distress than those with normal birth weight. Simiyu d sepsis . We alsod sepsis . Kouam ad sepsis  while Keal death .We acknowledge the following potential limitations: our study was carried out in only one health facility, and we did not include a substantial number of women who put to birth at home; thus results might not reflect the situation in the whole Health District nor in all sub-urban areas in Cameroon. Also, the retrospective phase was subjected to a potential risk that some of the records were not correctly filled. Furthermore, some of the risk factors like the mother’s income, history of fever in pregnancy and the level of alcohol consumption were subjective as they were based on the mother’s recall. Some other risk factors like recreational drug use, cigarette smoking during pregnancy may have been overlooked as some women may deliberately deny in order to appear socially virtuous. Nevertheless, this is the first report to the best of our knowledge that sets a cut-off for LBW for local use, on a sample of almost 5000 newborns. Despite the small sample size in the prospective phase, we used robust statistics to identify strong predictors of LBW, that are worth preventing.Overall, our results suggest that the definition of LBW in sub-urban areas in Cameroon may need to be raised so as to allow all babies < 2600 g to benefit from close care. However, this finding needs to be confirmed by other studies. One out of every five babies are born with a LBW. These neonates are more likely to suffer from neonatal asphyxia, foetal distress, respiratory distress and death. If the predictors identified in this study were systematically screened during antenatal care and delivery and managed appropriately, this would reduce the morbidity and mortality due to LBW and contribute to the achievement of the Millennium Development Goal 4. Similar studies in urban areas are required in order to generalize the results to the whole country and sub-Saharan Africa, especially because confirming our data wouldl increase the proportion of newborn who deserve special care, with consequences on health expenditures.


Although there is some evidence supporting the existence of an association between prenatal maternal or postnatal child’s urine phthalate metabolite concentrations and poor attentional performances, the interaction between urine phthalate metabolite levels and genetic variation for neuropsychological deficit of attention-deficit hyperactivity disorder (ADHD) has not been examined. The aim of this study was to determine whether phthalate metabolites in urine are associated with poor neuropsychological performance in children with ADHD, and whether such association is affected by genotype-phthalate interaction. A cross-sectional examination of urine phthalate metabolite concentrations and the continuous performance test (CPT) were performed in 179 Korean children with ADHD recruited from department of psychiatry of university hospital. Correlations between urine phthalate metabolite concentrations and the CPT scores were investigated, and the interaction of phthalate metabolite levels with the selected polymorphisms at major candidate genes for ADHD, namely dopamine receptor D4 (DRD4), dopamine transporter, α-2A-adrenergic receptor, and norepinephrine transporter genes. For the subjects with the DRD4 4/4 genotype, there were significant associations of the urine phthalate metabolite concentrations with the number of omission errors, the number of commission errors, and the response time variability scores on the CPT. However, for the subjects without the DRD4 4/4 genotype, no significant associations were found. The results of this study suggest a possible association between phthalate metabolite concentrations and poor attentional performances of ADHD as well as a genetic influence on this association. Further prospective and epigenetic studies are needed to investigate causality and pathophysiological mechanisms. They are divided into two distinct groups, with different applications, toxicological properties, and classification, based on the number of carbon atoms in their alcohol backbone. High molecular weight (HMW) phthalates, or high phthalates, include those with 7–13 carbons in their backbone, which gives them more permanency and durability. Low molecular weight phthalates (LMW), or low phthalates, are those with only 3–7 carbon molecules in their backbones [n-butyl phthalate (DBP), diisobutyl phthalate (DIBP), and benzylbutyl phthalate (BBP)) are classified as category 1B reproductive agents (Regulation (EC) No. 1272/2008) [Phthalates are a group of synthetic plasticizers and solvents that are used in a wide variety of commercial products, including food packaging, polyvinyl chloride tubing, medical equipment, toys, and cosmetics. Due to their high-production volume, common use, and widespread environmental contamination, these compounds reach humans through ingestion, inhalation, and dermal exposure daily . Phthalaackbones . Europeaackbones . In the ecanol C1, either 72/2008) . Phthala72/2008) ,6.LMW phthalates are endocrine disruptors that show estrogen-like activity. There is a growing body of evidence showing that exposure to environmental endocrine disruptors such as phthalates may adversely impact child development  . ExperimIn particular, recent evidence supports the existence of an association between urine phthalate metabolite levels, attention-deficit/hyperactivity disorder (ADHD), and executive functioning. ADHD is a disorder primarily characterized by inattention, impulsivity, and hyperactivity, with a worldwide prevalence of 5.3% . PreviouADHD is a multi-factorial polygenic disorder, and evidence points to dysregulation of the dopaminergic and noradrenergic system being involved in the pathophysiology of ADHD . Its leaThe genetic heritability of ADHD is reported to be approximately 75%, and environmental factors are estimated to account for 25% of the development of ADHD . Recent In this study, to elucidate the contribution of phthalates to the pathophysiological mechanisms leading to ADHD, we investigated urine phthalate metabolite levels with regard to their relationships with attentional performances in a sample of children with ADHD. The interaction of urine phthalate metabolite levels with the selected polymorphisms at two major candidate genes for ADHD, namely DRD4 andDAT1 was also examined in relation to neuropsychological measures.We recruited 179 children with ADHD from department of psychiatry of university hospital in South Korea. The recruited children were between 6 and 15 years old and had been diagnosed with ADHD according to Diagnostic and Statistical Manual of Mental Disorders, 4th Revision (DSM-IV) criteria as ascertained by a child psychiatrist. Exclusion criteria included the following: (1) a history of pervasive developmental disorder, mental retardation, bipolar disorder, psychotic disorder, obsessive compulsive disorder, or Tourette’s syndrome; (2) a history of organic brain disease, seizure disorder, or other neurological disorder; (3) an intelligence quotient (IQ) below 70; (4) the presence of learning disabilities or language disorders; (5) the presence of major depressive disorder, anxiety disorder, or tic disorder requiring drug therapy; and (6) any previous course of methylphenidate treatment lasting more than 1 year or occurring within the last 4 weeks. Children with ADHD, prescribed methylphenidate, were excluded due to potential confounding neuropsychological effects. To diagnose ADHD and any comorbid disorders, we used the Korean Kiddie-Schedule for Affective Disorders and Schizophrenia—Present and Lifetime Version (K-SADS-PL) . The KorThe children with ADHD were administered the Continuous Performance Test (CPT). The CPT is the neuropsychological test most widely used to measure inattention and impulsivity among children with ADHD. The Korean version of the CPT was standardized, and its validity and reliability are well established . Three vv/v) at a flow rate of 0.25 mL/min, and the eluates were monitored at target masses of 221, 293, and 291 and internal standard masses of 225, 297, and 295 [The spot urine samples were collected in 50 mL sterile specimen containers at the outpatient clinics in the morning and were refrigerated at −20 °C immediately. Refrigerated specimens were transported to the laboratory within 2 h. We measured the metabolites of DEHP and DBP among several phthalate compounds, because they were most widely used phthalates in personal-care products  and have been most widely linked to adverse health effects ,19. The  and 295 . We usedGenomic DNA was extracted from blood lymphocytes using a Genomic DNA Extraction Kit . DAT1 was localized on chromosome 5p15.3. The 40-base pair VNTR polymorphism located in the 3′-UTR of DAT1 was genotyped, as previously described . T7-5 Loi.e., omission errors, commission errors, or response time variability)  as an outcome. All regression models included a set of covariates based on established predictors of children’s cognitive and behavioral functioning: age , gender , years of parental education , yearly family income , subtype of ADHD , and IQ (continuous). The categorical variable  was incorporated in the linear regression analyses using dummy variable coding. All variables were concurrently entered into the model. Next, we conducted multivariate modeling to examine the relationships among the urine phthalate metabolite concentrations, DRD4 or DAT1 genotypes, and neuropsychological variables while including age, gender, years of parents’ education, yearly income, subtype of ADHD, and IQ as covariates. A genotype-by-phthalate metabolite concentration interaction term was also included in the model. In these models, the genotype variable dichotomized subjects into two groups. Thus, the subjects were dichotomized into those with the DRD4 4/4 or the DAT1 10/10 genotype and those with another genotype. This differentiation was selected because previous studies have reported an association between the 4-repeat allele homozygote of DRD4 with clinical and neuropsychological phenotypes of ADHD [Correlations between the MEHP, MEOP, and MBP concentrations were examined using Pearson correlation analyses. We conducted linear regression analyses to elucidate the associations between the urine phthalate metabolite concentrations and the neuropsychological variables. Nine set of regression analyses were performed using the (ln) concentrations of MEHP, MEOP, or MBP  as a principal predictor and each of the individual CPT measures  participated in the study between September 2010 and June 2012. p > 0.05). Among the genotypes of DRD4, the 4/4 genotype was observed in 96 (53.6%) out of 179 samples, the 2/4 genotype in 56 (31.3%), the 4/5 genotype in 14 (7.8%), and the 2/2 genotype in five (2.8%) each. The 2/5 and 3/4 genotypes were observed in three (1.7%) each and the 5/5 and 5/7 genotypes in one (0.6%). Among the genotypes of DAT1, the 10/10 genotype was observed in 148 (82.7%) out of 179 samples and the 9/10 genotype and the 7/10 genotype were observed in 10 (5.6%) each. The 10/11 genotype was observed in seven (3.9%), the 7/7 genotype in two (1.1%), and the 6/9 and the 6/10 genotype in one (0.6%).The distributions of the genotypes were all in agreement with the expected values of the Hardy characteristic equilibrium  concentrations of creatinine-corrected MEHP, MEOP, and MBP were 45.60 μg/g (geometric SD (GSD) = 2.41; range: 2.95–892.65), 43.82 μg/g , and 68.03 μg/g , respectively. Urine MEHP, MEOP, and MBP concentrations were highly correlated with each other .B = 15.52, 95% CI = 5.36–25.69 for a 1-unit increase in natural log-transformed urine MEOP concentration) and response time scores were positively and significantly associated with the MBP concentrations   .p = 0.012) and commission errors . We also found a trend of an interaction of the MEOP concentrations with the DRD4 genotype in relation to omission errors  and response time variability  and a trend of an interaction of the MBP concentrations with the DRD4 genotype in relation to omission errors   . The intB = 19.66, 95% CI = 7.38–31.95) and the response time variability scores  and of the MEOP concentrations with the number of omission errors , the number of commission errors , and the response time variability scores .Next, we conducted linear regression analyses using the CPT variables as the outcome and the urine phthalate metabolite concentrations as the predictor within each genotype; thus, separate models were created for subjects with the DRD4 4/4 and other genotypes. For the subjects with the DRD4 4/4 genotype, there were positive and significant associations of the MEHP concentrations with the number of omission errors  in the subjects with the DRD4 4/4 genotype. However, for the subjects without the DRD4 4/4 genotype, no significant associations were found  were higher than those in children and adolescents aged 6 to 19 years in the previous community study of Korea   and thosConsistent with previous studies , we founIt is intriguing that the associations between the urine DEHP metabolite concentrations and the CPT results were observed only in subjects with the 4/4 genotype of DRD4. We could speculate that, for genetically susceptible subjects, neural substrates associated with attentional systems may be more susceptible to DEHP. The 7-repeat allele of the exon III VNTR polymorphism of the DRD4 gene—a risk allele of ADHD in European or Caucasian subjects—is known to result in a blunted response toward dopamine . Asians,Although the mechanism underlying a possible association between phthalates and neurodevelopment has not been established, it is possible that the toxicity of phthalates is attributable to degeneration of dopaminergic neurons, leading to the hyperkinetics observed in rats in cases of 6-hydroxydopamine procedures . Indeed,This study had several limitations. First, because our data were cross-sectional and correlational, no inferences about causality are possible at this time. Therefore, further research using prospective designs is needed to investigate causality. Second, there was no control group. To determine whether the influence of DRD4 genotype-phthalate metabolite levels interaction on attentional performance is specific to ADHD patients or not, we should have obtained phthalate metabolite levels and neuropsychological and genetic data from healthy controls. Third, because we excluded the children with ADHD who have been on methylphenidate treatment, the most severely affected children may be excluded from evaluation which could affect the study results. Finally, the sample size of the present study was relatively small for genotypic analysis, thus the results should be carefully interpreted.In conclusion, the results of this study suggest the possibility of an association between phthalate metabolites and the severity of attentional deficits in children with ADHD and raise the issue of a genetic influence on this association. Further epigenetic studies are required to investigate the contribution of phthalates to the epigenetic pathophysiological mechanisms leading to cognitive changes.


Reading is a multifaceted skillset that has the potential to profoundly impact a child’s academic performance and achievement. Mastery of reading skills is often an area of difficulty for children during their academic journey, particularly for children with Attention Deficit/Hyperactivity Disorder (ADHD), Specific Learning Disorder with Impairment in Reading (SLD-R), or children with a comorbid diagnosis of both ADHD and SLD-R. ADHD is characterized by executive functioning and impulse control deficits, as well as inattention and impulsivity. Among the academic struggles experienced by children with ADHD are challenges with word reading, decoding, or reading comprehension. Similarly, children with SLD-R frequently encounter difficulties in the development of appropriate reading skills. SLD-R incorporates dysfunctions in basic visual and auditory processes that result in difficulties with decoding and spelling words. There have been limited empirical studies investigating the efficacy of interventions to improve the reading ability of children with both ADHD and SLD-R. Research studies that have focused on reading interventions for children from this population have predominantly included the use of medication treatments with stimulants  and non-stimulants . This review paper will present and integrate findings from empirical studies on successful medication treatments for children with comorbid ADHD and SLD-R. Furthermore, this paper will extend findings from empirically successful medication treatments to provide directions for future research. Developing reading competency is a critical learning milestone for children. Reading is a multifaceted skillset that has potential to profoundly impact a child’s academic achievement. It is a complex process consisting of two primary components: word recognition (decoding words and sight word reading) and comprehension . Thus, attaining a level of success as a reader requires proficiency in a range of foundational and interrelated skills whereby the reader uses knowledge of syntax, semantics, pragmatics, and phonology . Given tSpecific learning disorder (SLD) collapses the previously used terms of “learning disorders” (LD) and “academic skills disorders”, and includes impairments in the domains of reading, written expression, and mathematics . SLDs arADHD is a neurodevelopmental disorder that is characterized by executive functioning (EF) and impulse control deficits, as well as inattention and impulsivity . ChildreIn It is estimated that ADHD affects between 8–20% of school aged children , while tReading is an effortful, complex task that requires sustained attention. Given the challenges associated with ADHD, particularly those related to EF, it is unsurprising that reading may be an area of difficulty for these children . For exaChildren with ADHD may also present with deficits in reading comprehension . HoweverAttention-Deficit/Hyperactivity Disorder, reading disabilities, treatment, and medication. The search of peer-reviewed articles was limited to years 1995–2016 to ensure that included papers were recent, given the advances in medication efficacy and treatment-based research in the past 20 years, and were included if they assessed the efficacy of medication treatments for children with comorbid ADHD/SLD-R. Studies that examined treatments for ADHD or SLD-R independently were not included. For comparison, a brief review of papers published prior to 1995 is included for comparison. Given the limited literature in the area of medication treatment for children with ADHD and SLD-R, only 6 relevant empirical papers have been included as the main focus of the review.The following section provides a detailed review on what is known about treatments for children with comorbid ADHD and SLD-R (ADHD/SLD-R). Empirical studies and articles for this literature review were obtained through searches using the PsycINFO database, as well as Google Scholar to ensure inclusion of all relevant papers. The key search terms included Much of the existing literature addressing treatments for children with ADHD have focused on remediating the core deficits associated with the disorder  rather than working to improve academic difficulties . HoweverHistorically, research in the 1980s and early 1990s yielded results questioning the efficacy medication treatments for children with reading disorders. Uncertainty existed over whether stimulant medication could also be used to aid academic performance rather than simply addressing behavioral challenges . A meta-Although stimulant medication is commonly used to treat the symptoms of ADHD , for improving reading skills in children with ADHD/SLD-R has also been examined. Atomoxetine has been found to effectively treat behavioral ADHD symptoms. Specifically, atomoxetine has been found to effectively reduce ADHD symptoms in children with ADHD only and ADHD/dyslexia . ImproveAtomoxetine has also been found to improve visuospatial working memory and, to a lesser degree, inhibition in children with ADHD/RD . It is tDespite conflicting findings, results from recent studies involving stimulant and non-stimulant medication treatment options for children with ADHD/SLD-R optimistically suggest both forms of medication may contribute to improved reading outcomes. Although these medications do not directly target enhancement of reading skills, they play a role in supporting EF skills, such as working memory, processing speed, and attentional focus. These EF abilities play a key role in reading; thus, directly supporting these abilities at a neural level may allow children with ADHD/SLD-R to develop the building blocks needed to further their learning of reading-related skills.Review of the literature on medication treatments to improve reading related challenges in children with ADHD/SLD-R has shown that stimulant and non-stimulant medications may be effective in treating ADHD symptoms . In partAnother area sorely lacking research focus involves non-medicinal options for children with ADHD/SLD-R, with a need to build reading strategies or programs to improve literary skills in this population. Specifically, there is a need to consider the behavioral implications of ADHD in the creation of reading support programs for those with ADHD/SLD-R. For instance, inclusion of behavioral improvement strategies that focus on strengthening EF abilities in literacy programs may further benefit children with ADHD/SLD-R. Expansion of future research towards non-medicinal treatments may lead to effective alternative or concurrent treatment for children who do not respond to medication or for families who are looking for alternative options.Reading is a multifaceted process that combines mastery of word recognition and comprehension; proficient use of these skills is often a challenge for children with ADHD, SLD-R, and ADHD/SLD-R . The impAll authors listed, have made substantial, direct and intellectual contribution to the work, and approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewers GKA and BS and handling Editor declared their shared affiliation; the handling Editor and Chief Editor both state that the process nevertheless met the standards of a fair and objective review.


N-heteroaromatics are known to be poor partners in cross-metathesis reactions, probably due to catalyst deactivation caused by the presence of a nitrogen atom. However, some examples of ring-closing and cross-metathesis involving alkenes that incorporate N-heteroaromatics can be found in the literature. In addition, recent mechanistic studies have focused on the rationalization of nitrogen-induced catalysts deactivation. The purpose of this mini-review is to give a brief overview of successful metathesis reactions involving olefins containing N-heteroaromatics in order to delineate some guidelines for the use of these challenging substrates in metathesis reactions.Alkenes containing  In this review, we would like to give an overview of successful metatheses involving alkenes that possess N-heteroaromatics in order to delineate some guidelines. Some mechanistic insights dealing with catalyst deactivation caused by amino derivatives will be first presented and discussed. RCM and CM involving alkenes possessing N-heteroaromatics will be then successively examined [A large array of functional groups including alcohols, halides, esters, amides, carbamates and sulfonamides are compatible with the metathesis conditions –20. Howech works –26. Lewich works –29. As ach works –35. In ach works –37. Invoexamined .1 and 2 derived from GI and GII had a half-life of 40 min and 5 h 40 min, respectively at 55 °C and the main byproduct CH3PCy3+Cl− was identified using 1H, 13C and 31P NMR data as well as HRMS data. The deactivation of the catalysts was hypothesized to go through ligand dissociation from 1 and 2 followed by a nucleophilic attack of the free phosphine on the methylidene intermediates 3 and 4 to give CH3PCy3+Cl− and inactive ruthenium complexes. Similar observations were made in the absence or in the presence of ethylene in the reaction medium , pyrrolidine (b), morpholine (c) and DBU (d) were examined by 1H NMR. As already highlighted by Moore et al., in the presence of n-butylamine, GII was transformed into 8 and the latter slowly decomposed  to give ruthenium species and amine 10 as the major identified organic compound. This amine would come from the attack of the non-bulky n-butylamine on the hindered benzylidene. With more sterically hindered amines b–d, the ruthenium complexes 11b–d, resulting from phosphine displacement, proved to be stable even after 24 h at 60 °C  induced a fast decomposition of the methylidene 2 (b) and morpholine (c) are less detrimental to the catalyst , comparable results with those obtained with GII were obtained. In the presence of a non-bulky primary amine such as n-butylamine, the bis-aminobenzylidene 17 was formed and complete decomposition was noticed after 12 h at rt yielding ruthenium complex 18 and amine 10. In the presence of secondary amines b and c and sp2 amine d, ruthenium complexes 19b–d possessing one amine were formed and proved to be thermally stable. When the G-HII catalyst was treated with pyridine (e), the stable bis-pyridyl adduct 20e was formed in equilibrium with G-HII and no significant decomposition of the catalyst was observed -(+)-muscopyridine, Fürstner and Leitner have constructed the 13-membered ring macrocycle using a RCM applied to diene 34 [34 was first treated with HCl to form the corresponding hydrochloride salt which was then reacted with the ruthenium catalyst 36 under diluted conditions to deliver 35. After reduction of the double bond, the targeted (R)-(+)-muscopyridine was isolated  [Another example of RCM involving alkenes that possess 2-chloropyridines was reported to produce dihydroisoquinoline ine (56) . The add59 was prepared by a RCM of diene 58 that incorporates a quinoline moiety [Tricyclic compound e moiety . In thisN-heteroaromatics have been prepared using a RCM reaction. Shirbate et al. used a RCM to synthesize normuscopyridine and analogues [60 was treated with GI, the expected macrocycle 61 was obtained (51%) together with the dimeric cyclophane 62 (20%). The authors explained that the sulfone moieties facilitated the RCM by steering the alkenyl chains into a favorable conformation, but it also may be hypothesized that the steric hindrance caused by the sulfone groups might reduce the ability of the nitrogen atom in deactivating the ruthenium catalyst. A desulfonylation followed by a hydrogenation of the double bond afforded normuscopyridine  (68 (5 equiv) was detrimental to the reaction as 69 was isolated in a poor yield of 23%. This observation might be explained by the deactivation of the GI catalyst caused by the quinoline (The cross-metathesis between  (168 h) , entry 1 (168 h) , entry 2 (168 h) , entry 3uinoline , entry 470 as one of the two partners  and a large excess of cis-1,4-diacetoxy-2-butene  delivering the corresponding alkene 74 in 85% yield . It should be noted that in this case, the CM proceeded smoothly delivering the desired olefin in 78% yield despite the presence of the pyridine. Worthy of note, the amount of crotonaldehyde added in the reaction was not given in the article  and CM involving allyl sulfides that contain functional groups commonly found in DNA-intercalators and N-heteroaromatics were investigated. When a quinoline was present on the allylic sulfide, allylic alcohol was found to be the unique suitable partner among the tested olefins. In addition, 20 equiv of allylic alcohol were required and the CM product was obtained in a moderate 53% yield. Cross-metathesis of 81 with amide 83 or alkene 85 gave no conversion  using a catalytic amount of the G-HII catalyst to give 92 with a very good yield of 88% -lyconadin A . Alkene d of 88% .N-heteroaromatics could be performed by the introduction of a suitable electron-withdrawing group on the N-heteroaryl ring [93, bearing a pyridine without any substituent at C2 or C6, was treated with methyl acrylate in the presence of G-HII catalyst no reaction took place and the starting material was fully recovered. By contrast, the presence of a chlorine substituent at C2 on the pyridyl ring restored the reactivity of the olefin in the CM as the expected product was isolated in 84% yield (It should be noted that, in this case, the pyridyl ring is substituted by a methoxy group and a bromide and these substituents might be non-innocent in the success of the CM. The presence of 2 substituents at C2 and C6 may cause steric hindrance and the bromine atom at C3 may decrease the basicity of the nitrogen atom through inductive effect. Indeed, in a recent study published by our group, it was demonstrated that successful CM involving alkenes that contain ryl ring . When ol4% yield . We hypo98f in a moderate 52% yield (Various substituents on the pyridyl ring such as halides, trifluoromethyl or triflate groups were found to be suitable basicity modulators and the alkenes containing the corresponding disubstituted pyridines were efficiently coupled to methyl acrylate by utilizing a CM reaction. In addition, steric hindrance next to the nitrogen atom could also play a role by decreasing the nucleophilicity of the nitrogen as attested by the formation of alkene 2% yield .N-heteroaromatic moieties such as pyridines, pyrimidines, imidazoles and pyrazoles (This strategy was applied to the formation of a broad variety of disubstituted olefins containing yrazoles .N-heteroaromatics in RCM and CM. In RCM, GI and GII are usually preferred and diluted conditions are recommended to avoid dimerization. The most studied strategy allowing the use of olefins bearing N-heteroaromatics is the formation of the N-heteroaromatic salt prior to metathesis. The salt can be either isolated before metathesis or formed in situ using acidic additives. Alternatively, introduction of bulky and/or electron-withdrawing substituents on the N-heteroaromatic ring allows the metathesis to proceed by preventing nitrogen-induced catalyst deactivation. However, no general study dealing with the influence of the N-heteroaromatic substituents on the outcome of the RCM has been led so far. In CM, G-HII may be considered as the most potent catalyst even if some examples involving GII catalyst are described in the literature. Two strategies can be adopted to use olefins possessing N-heteroaromatics as one of the partner. When the second partner is non-expensive, it can be introduced in large excess thus avoiding the N-heteroaromatic induced catalyst deactivation. As an alternative, bulky and/or electron-withdrawing substituents can be introduced on the N-heteroaromatic to reduce the basicity of the nitrogen atom and thus the deactivation. This strategy appears as the most promising especially as a simple chlorine substituent is sufficient to allow the metathesis to proceed (From the selected examples discussed above, we tried to delineate some trends regarding to the use of alkenes possessing  proceed .N-Heteroaromatics are known to have a deleterious impact on metathesis by inducing ruthenium catalysts deactivation. Based on NMR and kinetic mechanistic studies, Lewis and/or Brønsted basicity of amines appeared to be responsible for the degradation of the catalyst. The most common solution proposed to circumvent the problem is the protonation of the nitrogen atom of N-heteroaromatics prior to the metathesis that can then be carried out using the corresponding salts. By close examination of the successful metatheses involving alkenes that possess non-protonated N-heteroaromatics, the presence of electron-withdrawing and/or bulky substituents on the heteroarene was noticed to be beneficial. These substituents can allow a fine tuning of the basicity and/or nucleophilicity of the nitrogen thus preventing the catalyst deactivation. By unravelling catalyst deactivation pathways, mechanistic investigations could help to extend the scope of the metathesis reactions to alkenes containing N-heteroaromatics, thus overcoming one major barrier to the widespread use of metathesis, particularly for industrial purposes.