Objectives: This research investigates the association of malnutrition with social and economic factors in general and environmental factors in specific such as sanitation facilities and drinking water sources for Pakistan. Methods: Authors used the latest data of 1010 Under-Three children from Pakistan Demographic and Health Survey (PDHS) 2017–2018. Cumulative Index of Anthropometric Failure (CIAF) was developed to measure the malnutrition status among children based on z-scores of WHZ, WAZ, and HAZ, respectively. The study has applied the discrete-choice logistic methodology to find the relationship of malnutrition with socio-economic characteristics. The interaction terms of drinking water source and sanitation facility have been measured to see the impact of environmental factors on child malnutrition. Results: The study results depict that the likelihood of malnutrition increases when the child had diarrhea recently and the child belongs to the deprived region such as KPK, Sind, and Baluchistan. However, the chances of child malnutrition drop with (1) an escalation of mothers’ education, (2) a rise in wealth status of the household, and (3) the improved water source and sanitation facility in the household. The only water-improved sanitation category of the interaction term is significant in the model which depicts that households having both improved water and improved sanitation facilities had very fewer chances of malnutrition among their children. Conclusion: Authors conclude that malnutrition in younger children is associated with improved water as well as sanitation facilities, maternal education, and household wealth in Pakistan. Malnutrition is a multi-dimensional problem that is caused by multiple socio-economic and environmental determinants. The prevalence of malnutrition is highest in low- and middle-income countries . In the Malnutrition impacts the development of children in many ways which varies based on socio-economic background and type of malnutrition . For ExaSome studies on child malnutrition found that water, sanitation, and hygiene (WASH) is a prominent determinant in South Asia ,11,12, iThis research is essential on two accounts. First, there is a dearth of evidence on determinants of malnutrition in Under-Three children focusing in specific on socioeconomic and environmental factors utilizing the latest 2018 PDHS data set. Second, this study measures the interaction of sanitation and water facility on child malnutrition. Therefore, the research hypothesis is that malnutrition in Under-Three children is associated with many proximate factors, especially environmental indicators. Literature is available on water sources and sanitation facilities in Pakistan while no study used interaction terms to analyze the combined effects of sanitation and water facility in the case of Pakistan, which is the gap this study has covered. Above all the results of the study may be used in identifying the public policy solutions for combating child malnutrition and morbidity.Most of the researches on the assessment of child malnutrition pursue the utility-maximizing model by postulating the production function of households ,23. ThisiN is taken as the standard measurement of anthropometry for a child. C shows consumption, W represents the vector of specific children and maternal factors; H represents the vector of specific household and environmental factors; Z represents the vector of health factors, while the error term of children-specific is ε.The reduced specified form of the nutrition production function for the study is:CIAFi = f .For this study, PDHS 2017 to 2018 data set was used for the analysis with a sample of 1010 children aged less than three years. This data provided wide information on nutrition and demographic characteristics, women, and children nutritional and healthcare information, women empowerment, domestic violence, etc. The study used anthropometric measurements of eligible Under-Three children. The statistical analysis was conducted using anthropometric measurements. Furthermore, data on household characteristics, child and mother specific factors, child disease factors, and environmental and socioeconomic characteristics were used in this study.The study used information on the children’s height, weight, and age from the PDHS 2017–2018 to construct indices. As per WHO (2009) standards for growth , three iIn this study, to measure child malnutrition, the CIAF was developed. The CIAF classification divides the children into seven (7) different categories: (1) No Failure, (2) Only stunted, (3) Only wasted, (4) Only under-weight, (5) Both (stunted and underweight), (6) Both (wasting and underweight), and last is (7) . The total measure of child malnutrition prevalence is calculated by combinations of all except group A. The binary variable “1” is used if a child is malnourished otherwise use “0” if a child is not malnourished.The explanatory variables of this study are defined and reported in The study developed a hypothesis that malnutrition in younger children depends on many proximate indicators . Logistic regression was used to measure the relationship between proximate variables  and the outcome variable . The study develops the CIAF index to measure child nutrition status.The explanation of the binary logistic model is:In binary form CIAFin and Yin are equal. The response is either success or failure more easily either child malnourished or not which is coded 0 or 1 value. However, here in this study Y is child malnutrition status and study assessing its association with multiple explanatory variables . The model specification and reduced form of multivariate logistic regression which estimates the probability scores and odds ratios of the outcome variable (CIAF) conditioned on explanatory variables is:In the above equation, Yi denotes the outcome variable (CIAF), Xi represents the explanatory variables, coefficients are β’s, which explains the degree of association with the dependent variable CIAF, while the error term is ε.p < 1%, p < 5%, and <10%. The empirical testing has been performed on Stata version 15.Three levels of significance were used in the logistic regression to show the significant relationship of the independent variable with the outcome variable: This research examined the impact of sanitation and water quality on child malnutrition. PDHS data were analyzed for each variable. The percentage of CIAF occurrence in a child was given according to different characteristics in The data analysis indicated that undernutrition prevalence was (26.45%) among children who had an un-improved source of water in their houses. Similarly, malnutrition was (36.27%) among children who had un-improved sanitation facilities in their houses.In The results of interaction terms for water and sanitation depict that only improved water and improved sanitation categories are significantly contributing to malnutrition reduction in children. It shows that households who have both improved water and sanitation had less likelihood to encounter the prevalence of malnutrition among their children .2, had  lower odds of malnutrition among their children. These results are compatible with some studies conducted across the world [The empirical estimations illustrated that mothers with primary and high education had lesser chances of malnutrition among their children. Some of the previous studies also support the results that mothers’ education is a significant determinant of malnutrition ,25,26,27he world ,29,30. Ahe world .Diarrhea, one of the major child malnutrition and infant mortality, becomes more dangerous if the child belongs to a deprived family . The stuThe results for the regions showed that children belonging to Sindh, KPK, and Baluchistan provinces had higher chances of becoming malnourished. Variation in nutrition existed on a regional basis. One study shows that in Pakistan, higher malnutrition exists among females in Baluchistan and Sindh compared to KPK and Punjab . AnotherImportantly, the study showed that when the household had improved water along with improved sanitation facilities, the chances of malnutrition among children decreased. Empirical evidence from the African and Asian regions shows that hygienic water for drinking and improved and quality sanitation facilities significantly reduce the degree of morbidity, mortality, and malnutrition among younger children . A studyFew of the regional studies in Pakistan highlight that improved water and sanitation are significant predictors of malnutrition ,49,50 anThis study has examined only the socio-economic and environmental determinants of malnutrition among under-three children in Pakistan. However, child malnutrition can also be influenced by several other significant factors which need to be explored in future studies. Cultural and structural variables can also play important role in determining malnutrition among under-three children in Pakistan.This study suggests that malnutrition in younger children is associated with multiple socioeconomic and environmental determinants in Pakistan. The results of this research show that significant reasons for under-three malnutrition in Pakistan are regional disparities, diarrhea, maternal education, wealth index, unimproved water source, and unimproved sanitation facility in the households. Therefore, the study urges a redirection of resources from megaprojects towards community development projects such as investment in improving water and sanitation facilities, as well as education and employment for women.


In actual application scenarios of the real-time video confidential communication, encrypted videos must meet three performance indicators: security, real-time, and format compatibility. To satisfy these requirements, an improved bitstream-oriented encryption (BOE) method based chaotic encryption for H.264/AVC video is proposed. Meanwhile, an ARM-embedded remote real-time video confidential communication system is built for experimental verification in this paper. Firstly, a 4-D self-synchronous chaotic stream cipher algorithm with cosine anti-controllers (4-D SCSCA-CAC) is designed to enhance the security. The algorithm solves the security loopholes of existing self-synchronous chaotic stream cipher algorithms applied to the actual video confidential communication, which can effectively resist the combinational effect of the chosen-ciphertext attack and the divide-and-conquer attack. Secondly, syntax elements of the H.264 bitstream are analyzed in real-time. Motion vector difference (MVD) coefficients and direct-current (DC) components in Residual syntax element are extracted through the Exponential-Golomb decoding operation and entropy decoding operation based on the context-based adaptive variable length coding (CAVLC) mode, respectively. Thirdly, the DC components and MVD coefficients are encrypted by the 4-D SCSCA-CAC, and the encrypted syntax elements are re-encoded to replace the syntax elements of the original H.264 bitstream, keeping the format compatibility. Besides, hardware codecs and multi-core multi-threading technology are employed to improve the real-time performance of the hardware system. Finally, experimental results show that the proposed scheme, with the advantage of high efficiency and flexibility, can fulfill the requirement of security, real-time, and format compatibility simultaneously. Real-time video communication is widely used in military, business, entertainment, and personal social activities, such as video conferencing, live video, and video surveillance ,2,3,4. HTo realize the end-to-end encryption for the communication video, security, real-time, and format compatibility are important technical indicators that must be met simultaneously for the real-time video confidential communication system ,13,14,15n-D  self-synchronous chaotic stream cipher algorithms (n-D SCSCA) [n-D SCSCA  still have security loopholes. Lin et al. [n-D SCSCA  that employ the lower eight-bits of the multiplication result of multiple chaotic variables as the chaotic pseudo-random sequence. n-D SCSCA  increase the computational complexity of the chaotic pseudo-random sequence expression, so that cryptanalysts cannot obtain enough nonlinear equations through DCA-TSNCIC to solve the original secret keys of the encryption algorithm. However, they cannot further resist the divide-and-conquer attack traversing multiple non-zero component initial conditions (DCA-TMNCIC) that is more powerful than the DCA-TSNCIC [To meet the above three indicators simultaneously, in recent years, people perform in-depth studies in encryption algorithms ,21,22,23D SCSCA) ,20,21 apn et al.  that empA-TSNCIC .In the existing video encryption scheme for H.264/AVC, they can be classified into full encryption (FE)  and seleAccording to the different relationships between encryption algorithms and video codecs, SE methods can be further subdivided into compression-integrated encryption (CIE) and bitstream-oriented encryption (BOE). The feature of CIE is that it has a coupling structure embedding the encryption algorithm into the video codec, where the video information is encrypted during encoding. The feature of BOE is that it has an independent architecture separating the encryption algorithm and the video codec, where the video information is encrypted after being encoded. Chen et al.  and ZhanTo address the above issues, for H.264/AVC video, an improved BOE is proposed and verified in an actual network environment upon the ARM-embedded hardware platform. The main contributions and novelties of this work can be summarized as follows:(1) A 4-D SCSCA-CAC is proposed, which can effectively resist the cryptanalysis method combining a chosen-ciphertext attack with a divide-and-conquer attack. In addition, the chaotic bit sequences generated by 4-D SCSCA-CAC for encrypting video information have passed the NIST and TESTU01 test.(2) An improved BOE method based on chaotic stream ciphers is proposed, which separates apart the hardware codec and 4-D SCSCA-CAC to form an independent architecture. The proposed scheme can achieve the format compatibility of encrypted videos and balance the technical contradiction between security and real-time performance.(3) An ARM-based hardware system for real-time video confidential communication is designed and implemented, whose experimental results give a practical and objective evaluation for the critical issues about security, real-time, and format compatibility, verifying feasibility and effectiveness for the BOE method.The rest of the paper is organized as follows: n-D SCSCA  [In order to solve the above security problem of 3, 7, 8) ,20,21, on-D SCSCA , and combining with the cryptanalysis process of chosen-ciphertext attack and divide-and-conquer attack, the security loopholes of n-D SCSCA  are analyzed in this subsection.According to the structure characteristics of n-D SCSCA  and corresponding cryptanalysis methods are shown in The algorithm structure of n-D SCSCA  can be summarized as:From The general form of decryption expression can be summarized as follows:n-D SCSCA  are mod and sine function. When the ciphertext is set as Note that in Equation , settingn-D SCSCA .Compared Equation  with Equc.In SCSCA, initial conditions of arbitrary chaotic variables at the decryption end can achieve asymptotic synchronization with the decryption end, hence the cryptanalyst can arbitrarily select the initial conditions conducive to cryptanalysis. In the case of chosen-ciphertext attack, Equation  can be sn-D SCSCA , the secret keys can be cracked through the divide-and-conquer attack methods with different strengths, respectively. When n selection methods of initial conditions is as follow:Next, according to the different computational complexity of the chaotic pseudo-random sequence A-TSNCIC . With DCWhen A-TMNCIC  which haA-TMNCIC . With DCn-D SCSCA , due to Remarkably, in Equation  can be fThe principle of the divide-and-conquer attack is to decipher the information of secret key or secret key expression block by block. In Equation , f(aij) From the above method, a sufficient number of nonlinear equations about secret keys can be obtained, the correct information of the original secret keys can be deciphered by solving the nonlinear equations.n-D SCSCA  can be summarized as follows:According to the above analysis, the main problems of n-D SCSCA  are sine or mod function. In this case, when the cryptanalyst set ciphertext information as (1) To achieve self-synchronization, the ciphertext need to be fed back into the anti-controllers of the chaotic system, and the anti-controller types of n-D SCSCA  all use the lower eight-bits of a single chaotic variable or the multiplication result of multiple chaotic variables as the chaotic pseudo-random sequence. With the chosen-ciphertext attack, when all initial conditions are set as a same non-zero constant, a constant common factor can be extracted from the decryption expression. Consequently, by setting the appropriate value of the constant, the cryptanalyst can use the divide-and-conquer attack to obtain the complete information of the secret key expression. After acquiring a sufficient number of nonlinear equations about secret keys, the original secret keys can be successfully deciphered through solving the nonlinear equations.(2) In actual channel communications, initial conditions of arbitrary chaotic variables at the receiver can achieve asymptotic synchronization with the sender. Therefore, the initial conditions of the chaotic variables belong to the weak secret keys, and the cryptanalyst can arbitrarily select the initial conditions conducive to cryptanalysis. Besides, To deal with the loopholes of SCSCA analyzed in A.Design An Asymptotically Stable Nominal SystemAn uncontrolled 4-D discrete-time linear nominal system is expressed as:According to the design principle of discrete-time chaotic system , all eigFirst, the MATLAB rand function is used to generate a 4-D full rank matrix with uncorrelated random values in the range of . Next, a orthonormal matrix Q is obtained by orthonormalizing the 4-D matrix using the orth function. Finally, since all eigenvalues of orthonormal matrix are located on the unit circle on the complex plane, when matrix Q is multiplied by a coefficient less than 1, a matrix A with all eigenvalues located inside the unit circle on the complex plane can be obtained, given by:From Equation , one getB.The 4-D Controlled System Based Anti-control PrincipleAccording to the principle of anti-control of dynamical systems , selectil system , the 4-DThe corresponding Lyapunov exponents of the system  obtainedheorem 1 , the conC.4-D SCSCA-CACNote that, since application environment of the chaotic system is ARM-embedded platform in this paper, the following calculation operations are based on binary representation. The chaotic pseudo-random sequence Then, the ciphertext To realize self-synchronization, the ciphertext culation ,20,21, tThe main features of 4-D SCSCA-CAC are summarized as follows:(1) Unlike the anti-controllers shown in Equation , consequEquation  degrades(2) Note that an additive term is introduced in the modulo operation and the round-down operation in Equation ; resultiFrom the chosen-ciphertext attack method, it can be known that when the security analysis of 4-D SCSCA-CAC is performed, the cryptanalyst can arbitrarily select the ciphertext that is beneficial to the decryption algorithm and obtain the corresponding plaintext. When the ciphertext is set as Equation , which yFrom Equation , one canIn the decryption process, decryption end can achieve asymptotic synchronization with the encryption end under any given initial conditions, so the cryptanalyst can choose any initial conditions that are conducive to deciphering the encryption algorithm. In summary, when the ciphertext Firstly, by substituting Equation , the firThen, by substituting Equation , the secWith DCA-TMNCIC for 4-D SCSCA-CAC, the set of fifteen selection methods of initial conditions is as follow:Note that, in the case of choosing the ciphertext, the ciphertexts and corresponding plaintexts are both known. Therefore, by substituting the fifteen initial conditions in Equation  into equEquation  as folloThen, by setting the initial conditions as a same non-zero constant Equation , one getk increases, From Equation , the secposed in ,35 failsIn summary, the improved 4-D SCSCA-CAC proposed in this paper is safe against the combinational effect of the chosen-ciphertext attack and the divide-and-conquer attack.Transmission frame rate is an important indicator to represent the real-time performance of video communication systems, and 25 f/s is a basic requirement in actual application scenarios. Thus, promoting real-time performance is a primary goal in system design. In this paper, an optimized design is proposed that can be conducted from three aspects: (1) improve the BOE method for further reducing the computational load; (2) utilize the hardware codec accelerator on the chip to speed the system; and (3) adopt the multi-core and multi-threading technology to improve system efficiency in parallel work.The overall design scheme of the real-time video communication system based on the ARM platform and the BOE method is shown in The BOE and BOD are specific implementations for selective encryption and decryption, respectively. There are three main parts in the BOE and BOD modules in this paper, including H.264 entropy decoding, chaos encryption-decryption, and H.264 entropy encoding. In the chaos encryption-decryption part, the proposed 4-D SCSCA-CAC is used to encrypt and decrypt the H.264 bitstream. According to Equation , the 4-DOn the sender, as shown in On the receiver, the received In Multi-core multi-threading technology is another essential factor for improving real-time performance. The whole system can be divided into multiple threads. Each thread is executed by their according CPU in a parallel and pipeline manner. Better than the single thread operation, multi-core multi-threading technology is capable of solving the blocking and delay problems effectively and is beneficial to the execution efficiency.Established by the Moving Picture Experts Group (MPEG) consortium and the Video Coding Expert Group (VCEG), H.264/AVC is one of the most popular standards for video encoding. With the characteristics of low bit rate and high compression rate, H.264/AVC is widely used in video applications. H.264/AVC-based standard specifies three profiles, including baseline profile, main profile, and extended profile, in which each profile supports a specific type of application. The baseline profile is mainly used for high real-time video wireless communication application scenarios, while the main profile and extended profile are used for applications with relatively low real-time requirements such as video broadcasting or video storage. Therefore, to satisfy the real-time performance of the video confidential communication system, one considers the baseline profile in this paper. In this profile, only inter prediction and intra prediction are supported, and the H.264 bitstream is encoded by the CALVC and Exponential-Golomb coding methods.The H.264 bitstream is highly compressed bit sequences, and each bit data is closely related to the video encoding and decoding process. If arbitrary bit data is encrypted, the format compatibility of the encoded video may be destroyed. To achieve a format compatible and secure encryption scheme, firstly, one needs to understand the hierarchical structure of the H.264 bitstream and perform the encryption analysis for the syntax elements in H.264 bitstream. Finally, the syntax elements that can keep the video format compatibility after encryption will be selected as the encryption objects.The hierarchical structure principle of the H.264 bitstream is shown in In the H.264 bitstream, the syntax element is the basic unit of data, and each syntax element consisting of several bits represents a specific physical meaning. Different syntax elements are carried on the different types of the macroblock. For I-macroblock, there are Macroblock Type (Mb_type), Macroblock Prediction mode (Mb_pred), Coded Block Pattern (CBP), Quantization Parameter (QP), and Residual syntax elements. For P-macroblock, there are Mb_type, MVD, CBP, QP, and Residual syntax elements. The syntax element ‘Residual’, and other syntax elements, can be extracted by CAVLC entropy decoding and the Exponential-Golomb decoding method from the macroblock, respectively. Next, the above syntax elements will be analyzed one by one to determine whether they can be used for encryption.• Mb_type specifies the type of the current macroblock. If the Mb_type is encrypted, the encrypted macroblock cannot be recognized by the codec, so the Mb_type syntax element cannot be encrypted.• Mb_pred represents the prediction mode used to reconstruct the current block. Because the prediction modes applicable to macroblocks in different locations are different, if the encrypted value of Mb_pred is not within the applicable prediction mode for the current macroblock, it will also lead to decoding failure, so the Mb_pred syntax element cannot be encrypted.• CBP refers to the coding scheme of the residual data of the current macroblock, each bit of which represents the number of the luma component or chroma component in the current macroblock. It is related to whether there is luma or chroma component data in the bitstream. Therefore, the CBP syntax element cannot be encrypted.• QP is used to scale the prediction residual transform coefficients. Since the value of QP is limited in size, encrypting QP will cause greater data expansion. Therefore, the QP syntax element is not regarded as the encryption object in this paper.• Residual carries the main data of the macroblock, which includes the DC component and the Alternating Current (AC) component. Among them, the DC component has most of the information of the video image. If the DC component is encrypted, the image information can be encrypted to the maximum extent. Thus, DC component in Residual syntax element is the main encryption object.• MVD only exists in the P-macroblock, and it represents the motion direction of each sub-block in the current macroblock. Encrypting MVD will affect the reconstruction effect of the inter prediction image, so it can be encrypted.The BOE module is made up of entropy decoding, chaotic encryption, and entropy encoding. The design flow of the module is as follows:Step1: Parse the syntax elements from original H.264 bitstreamq in a I-macroblock is determined by Coded Block Pattern Chroma (CBPC) and Coded Block Pattern Luma (CBPL). The values of CBPC and CBPL and the corresponding value of q have the following four situations: ① When The macroblock z is determined by the division mode of the P-macroblock. When the division mode is ① For P-macroblock, DC components Step2: Encrypt the syntax elementsThe syntax elements are encrypted by 4-D SCSCA-CAC. When the current frame is an I-frame, the DC component in the I-macroblock is the only encrypted object. According to Equation , the encp(k)=se=se=sWhen the current frame is a P-frame, there are two types of macroblocks to be considered. In the I-macroblock, only the encrypted DC components need to be decrypted. In the P-macroblock, both the encrypted DC components and MVD coefficients need to be decrypted. The decryption expression is as follows:Step3: Re-encode the syntax elements as the original H.264 bitstreamAfter decryption, Algorithm 2: BOD operating proceduresThe execution flow of the BOD module is shown in Algorithm 2. Note that both the CAVLC entropy and the Exponential-Golomb coding operation in Algorithm 1 and Algorithm 2 are transplanted from JM86 and X264 software codec models.Multi-core multi-threading technology is an effective way to optimize system architecture and improve the efficiency of multitasking. The processing time for one frame on the sender includes video capturing i  with low computational complexity are both performed by CPU1, while Thread_i  with high computational complexity are executed by CPU2, CPU3, and CPU4, respectively. Moreover, threads exchange data through shared memories. Thread_i  share Buffer_1, Thread_i  share Buffer_2, Thread_i  share Buffer_3, and Thread_i  share Buffer_4. The buffer capacity is configured according to one frame size in YUV, RGB, or H.264 format.In Read–write conflict prevention is the most crucial working mechanism for shared buffers. It prohibits more than one thread to perform a reading or writing operation in the same buffer simultaneously. Otherwise, unpredictable errors will happen. The mutex lock mechanism can achieve the read–write conflict protection, whose working principle is illustrated by switches In summary, the BOE and BOD modules have the advantages of high efficiency and good real-time performance. Besides, the hardware codec solves the time-consuming problem of encoding operation, and the multi-core multi-threading technology further optimizes the system. As a result, the operation period of all threads are constrained to less than 40 ms. Experiment results prove that the frame rate of the embedded hardware system is more than 25 f/s.According to the chaotic encryption and decryption algorithms given in Equations  and 25)25), as wThe real-time video confidential communication system is tested in the real network environment under the The experimental result of the original videos displaying at the sender is shown in The comparison of experiment results of the video confidential communication system based on ARM-embedded platform is shown in p-value. Sequences are said to pass a test if the calculated p-value > 0.01.NIST test is a strict and standardized test suite for testing the statistical characteristics of pseudo-random sequences generated by chaotic systems, and the total length of tested sequecnces are required to be at least p-value of each test for 4-D SCSCA-CAC. In this experiment, the 100 groups of bit sequence with length as Compared with the NIST test, the TESTU01 test is a more rigorous statistical characteristic test. TESTU01 has seven test suites, including SmallCrush, Crush, BigCrush, Alphabit, Rabbit, PseudoDIEHARD, and FIPS-140-2 suite. Among them, the amount of test sequences of BigCrush suite is as high as 10TB, which makes the dynamic behavior of chaotic system easier to be exposed. Even though some chaotic systems can pass NIST test, they cannot further pass the TESTU01 test. Therefore, if the chaotic sequences generated by the chaotic system can successfully pass the TESTU01 test, it shows that the chaotic sequence has better statistical performance and randomness.m, and then recovers the regular trajectories such as attractors in the embedded dimension space. The structure of some chaotic maps with complicated trajectory will become simple and evident in the reconstructed phase space. Therefore, the attacker can easily predict the behavior of the chaotic variable according to the trajectory in the reconstructed phase space. Next, the phase space reconstruction attack is used to test the state variable The phase space reconstruction attack is to analyze the time series of a state variable at different times, continuously produced by the chaotic system. It reconstructs the time series of the state variable by determining the appropriate delay time m is calculated as 4, and these two parameters are used to reconstruct the phase space. The estimating results of the delay time m are shown in By using the auto-correlation method and False Nearest Neighbor (FNN) method, the delay time When the chaotic system has a key parameter with a very small mismatch error, and the original video signal is not able to decrypt, the key parameters are very sensitive to the mismatch error. The smaller the number of the mismatch error, the better the security of the system.The sensitivity test results of key parameters mismatch for 4-D SCSCA-CAC is shown in PSNR can be used as a performance index to evaluate the perceptual security of encrypted video. When the PSNR value is lower than 20 dB, it means that original video information cannot be discriminated from the encrypted video by human eyes. PSNR is calculated based on the Mean Square Error (MSE) between the original image and the encrypted image. The mathematical expression of MSE is as follows:The mathematical expression of PSNR is obtained as:H and W denote the height and width of the video, respectively. k represents the pixel depth.Among them, Different from PSNR that measures image quality based on pixel error, SSIM measures image similarity from three aspects: brightness, contrast, and structure. The SSIM value is in the range of In order to test the encryption effect of the video confidential communication system, one intercepted three frames of original images and their corresponding encrypted images in the actual video communication process, as shown in According to For ensuring security, format compliance, and real-time transmission of encrypted videos, the SE method has become a research hotspot in the field of video encryption. In SE methods, with high computational efficiency, BOE is a more desirable encryption method compared with the CIE scheme. Some reports have studied and improved the BOE scheme, but these schemes lack the corresponding hardware implementation to prove the feasibility, effectiveness, and superiority of the BOE method. Moreover, some studies adopted AES block cipher as the encrypted algorithm in their BOE scheme with high computational load, increasing the time consumption in encrypting. To deal with these problems, in this paper, one proposed:(1) An improved algorithm 4-D SCSCA-CAC.(2) An improved BOE scheme utilizing the hardware codec to improve the real-time performance of video transmission.(3) An ARM-based hardware implementation of the BOE scheme.4-D SCSCA-CAC can resist the cryptanalysis combining of the chosen-ciphertext attack and the divide-and-conquer attack, and the chaotic bit sequences generated by 4-D SCSCA-CAC for encrypting video information have passed the NIST and TESTU01 test, ensuring the security of the video confidential communication system. In addition, due to the chaotic stream cipher having less computational overhead, without the consuming time for package construction to encrypt the fixed-length syntax elements, 4-D SCSCA-CAC is more appropriate for application in actual video communication than AES algorithm. Besides, one found that the hardware codec can be used for the BOE scheme in actual applications. The proposed scheme utilizes the hardware acceleration to improve the video transmission frame rate to 27 f/s. In contrast with hardware implementation based on the CIE method, the experimental results have proved that the BOE scheme is more suitable for real-time video secure communication application scenarios, and reflected the advantages of high efficiency and flexibility in the BOE scheme.


Cutibacterium acnes are increasingly recognized as causative agents of implant-associated infections (IAIs) in orthopaedic surgeries. SGAB IAIs are difficult to diagnose because of their non-specific clinical and laboratory findings as well as the fastidious growth conditions required by these bacteria. A high degree of clinical suspicion and awareness of the various available diagnostic methods is therefore important. This review gives an overview of the current knowledge regarding SGAB IAI, providing details about clinical features and available diagnostic methodologies. In recent years, new methods for the diagnosis of IAI were developed, but there is limited knowledge about their usefulness in SGAB IAI. Further studies are required to determine the ideal diagnostic methodology to identify these infections so that they are not overlooked and mistakenly classified as aseptic failure.Slow-growing Gram-positive anaerobic bacteria (SGAB) such as Aerobic bacteria, primarilystaphylococcal species, are the most identified organisms inculture-positive IAI. Slow-growing Gram-positive anaerobic bacteria (SGAB) are increasingly being recognized as potential agents in IAI, although their role is not well established, and their diagnosis is challenging . The purpose of this narrative review is to introduce and highlight all SGAB, including the rarer ones; to evaluate current diagnostic SGAB-IAI information from a clinical perspective, helping to guide the diagnostic process; and to identify areas for future research.two consecutive ultrasound-guided hip joint aspirations.A 68-year-old man presented with complaints of persistent pain from aprimary total hip arthroplasty (THA), which had been performed due toidiopathic osteoarthrosis 3 years prior. The immediate post-operativeperiod had been uneventful, but during the following 2 years heexperienced increasing hip pain. Due to a medical evaluation of generalmalaise and chronic elevated serum erythrocyte sedimentation rate (ESR), an In view of the patient's symptoms, imaging, and laboratory findings,prosthetic joint infection (PJI) was suspected based on modified Musculoskeletal Infection Society (MSIS) criteria , and revision of the THA was planned as per the CORIHA protocol . By the time the patient was admitted for revision surgery, he had developed a sinus tract from the THA to the skin, which in all classifications is a definite sign of infection. During the one-stage revision, five tissue biopsies were obtained as recommended by Kamme and Lindberg (1981). No growth was seen in any of the cultures after 14 d of standardized incubation.Cutibacterium acnes (C. acnes) was isolated from the sonicated fluid after 6 d of anaerobic incubation, with no growth presented in the aerobic cultures. The patient was treated as per local hospital guidelines for management of PJI. The patient had no pain or other sign of PJI recurrence at latest follow-up and had an eventless, contralateral, THA in the follow-up period due to idiopathic osteoarthrosis. The patient has given full written consent for the use of his case.Sonication of the implant was performed as part of an unrelated researchproject. Finally, 2SGAB comprise Gram-positive bacteria of the two phyla Firmicutes andActinobacteria that are usually slow-growing and require long cultivationtimes (Cutibacterium species (previously Propionibacterium):these Gram-positive, aerotolerant, anaerobic coryneform bacteria are part ofthe normal skin microbiota. The most common species associated with IAI areC. acnes  followed by C. avidum .C. acnes: although reported as a causative agent of IAI since the 1970s, it has gained more interest in recent years as a biofilm-producingpathogen . It is themost common anaerobic bacterium isolated in IAI and is most commonly seen inlate onset, chronic PJI . It has a predilection for the upper limb and the spine and isconsidered to be the most common organism causing shoulder PJI , but it is also found in PJIof hip, knee, and metacarpophalangeal joints, as well as spinal IAI . It is also the most common bacterium grown inunexpected positive cultures in revision shoulder arthroplasty and removedclavicle plates . C. acnes is a normal skin commensal. In patients undergoing primary shoulder surgery, it was found that Cutibacterium species were cultured from unprepared epidermal skin surfaces and freshly incised dermal edges in 72 % and 34 %, respectively . Studies have also reported the presence of Cutibacterium species in deep tissue cultures in patients undergoing primary shoulder arthroplasty despite thorough skin preparation and preoperative intravenous antibiotic prophylaxis .C. avidum: it is the second most common Cutibacterium species associated with IAI . It is mostly seen in PJI of the hip, especially when the anterior approach is used, but infections involving fixation plates of the femur, humerus, and prosthetic shoulder joints have also been reported .C. granulosum: the first case of PJI due to this bacterium was described in 2013 in a patient after THA .Finegoldia magna (previously Peptostreptococcus magnus):this Gram-positive anaerobic coccus is part of the commensal flora, found onhealthy human skin and as a part of the gut microbiota . Although less frequent than Cutibacterium species, PJIs of hip, shoulder, knee, and foot, as well as osteosynthesis-related IAI due to F. magna, have been reported .Staphylococcus saccharolyticus (previously Peptococcus saccharolyticus): this anaerobic coagulase-negative staphylococcus has been isolated from a limited number of cases of shoulder and hip PJI and spinal IAI .Parvimonas micra (previously Micromonas micros or Peptostreptococcus micros): a few cases of IAI due to this Gram-positive anaerobic coccus have been reported to date .Miscellaneous SGAB: in addition to the above, IAI due to rare SGAB like Slackia exigua, Robinsoniella peoriensis and Facklamia hominis have also been reported in case reports . With recent focus on Cutibacterium acnes and its role in IAI, many studies havebeen done on that species. But there is limited information on rarer SGAB,even though their role in IAI is not of any less importance.33.1Regarding the definition of PJI, different classifications have beenproposed by the Musculoskeletal Infection Society (MSIS), theInfectious Diseases Society of America (IDSA), and theEuropean Bone and Joint Infection Society (EBJIS) . Although there are differences, several criteria are present throughout all the guidelines, such as the presence of a sinus tract, histopathologic evidence of inflammation, and positive cultures from tissue biopsies or aspirations. In addition, evaluation of inflammatory cells and biomarkers, both in serum and synovial fluid, are also taken into consideration . Whether these criteria are stringently applicable for SGAB PJI remains uncertain, amongst others due to these organisms' specific growth requirements and in vivo reduced inflammatory response. Moreover, there are no established or widely accepted diagnostic criteria for non-PJI IAIs, making their diagnosis difficult and limiting the available data on non-PJI IAI, irrespective of the causative organism. As such, no clear classification has been established in regard to SGAB IAI.3.2Differentiation between SGAB IAI and aseptic failure based only on clinicalsymptoms is often extremely difficult, and a high degree of clinicalsuspicion is warranted, with pain being the most predominant feature.Persistent or increasing pain from an area with an orthopaedic implant andjoint stiffness in specific relation to PJI are the most common clinicalsymptoms reported in SGAB IAI. However, such symptoms are also frequentlypresent in cases of aseptic failure . Theclassical clinical features of IAI include fever, local signs of inflammation such as redness or warmth, pain and swelling, and a sinus tract. Fever and local signs of inflammation are not just non-specific but also observed less frequently in SGAB IAI than pain and joint stiffness . The frequency of a sinus tract in SGAB IAI has been reported anywhere from less than 1 % up to 20 % .C. acnes in revision shoulder surgery and found that they had no clinical relevance in at least 25 % of UPC cases .Several groups have analysed the clinical significance of unexpectedpositive cultures (UPCs) of 3.3Medical imaging is applied as routine first-line investigation in patientswith orthopaedic implants. But plain radiographs are neither sensitive norspecific for the diagnosis of IAI, irrespective of the causative organism asit is difficult to differentiate between infection and aseptic looseningbased on a single X-ray .C. acnes IAI as well as in IAI due to less frequent SGAB . However, it is difficult, if not impossible, to differentiate between aseptic and septic loosening  in these cases. Signs of osteitis, with osteolysis and/or periosteal bone formation, or abscess formation are some of the reported X-rays and ultrasonographic findings, respectively, of C. avidum-associated IAI . Nuclear medicine imaging has not been found useful in the diagnosis of SGAB in chronic shoulder PJI .Only a few studies have distinctly described X-ray findings in SGAB IAI,with signs of loosening being the most frequent finding seen in 23 %–73 % of 3.4In general, SGAB do not elicit a strong inflammatory response. Consequently,conventional inflammatory markers may not be elevated , and as such the value of existing serum and synovial biomarkers inSGAB IAI is questionable.C. acnes IAI , ESR/CRP cannot clearly differentiate between aseptic failure and SGAB IAI . They are not always elevated in C. acnes IAI , and when elevated, their levels are still lower compared to IAI caused by highly virulent microorganisms . Normal ESR and CRP have also been reported in IAI caused by infrequent SGAB . It should be noted that comparison between different studies is difficult, as different cut-off values were used for CRP  and that this also occurs in IAI due to more virulentorganisms . While ESR and CRPperform better compared to WBC count in the diagnosis of Synovial fluid and serum levels of interleukin-6 (IL-6) have been identifiedwith a high sensitivity and specificity in the diagnosis of PJI of hip andknee in general, but little is known about their usefulness in SGAB IAI . Serum IL-6 haspotentially a poor sensitivity and specificity and cannot currently berecommended as a preoperative diagnostic test in SGAB IAI .C. acnes shoulder PJI, studies have shown that synovial C. acnes IAI, but Weigelt et al. (2020) found that the ADLF test failed to identify the only culture-positive C. acnes shoulder PJI in their study . Overall, it is difficult to assess the ADLF test's potential in SGAB IAI of hip and knee, as few or no SGAB were included in any of the studies that showed high sensitivity and specificity of the ADLF in hip and knee PJI . Focus of future studies should be on evaluating the ELISA test in SGAB IAI.Synovial alpha defensins .The simple and inexpensive leukocyte esterase strip test  has an overall concordance of 86 %–93 % withculture results in hip and knee PJI in general . But its use in SGAB IAI might be limited, as the test could only correctly identify 3 of 15 Other biomarkers like serum D-dimer and synovial CRP are also included asminor criteria in an updated PJI definition .However, studies on D-dimer have shown conflicting results in IAI in general, similarly contradictiveresults have been seen in the role of synovial CRP , and their use in SGAB IAI has not been evaluated.Serum procalcitonin has also previously been evaluated and not found to beof value in the diagnosis of PJI in general .3.5Aspiration of synovial fluid is often performed in suspected cases of PJI.When no lavage has been performed and clear fluid is aspirated, synovialfluid cytology gives valuable information about the level of localinflammation . Elevated synovial WBC count is regarded as a diagnostic criterion in all major definitions of PJI . But different studies have mentioned different cut-offs. The latest EBJIS definition suggests synovial fluid WBC count of C. avidum PJI, the median synovial WBC count was reported to be high with a median differential count of 95 % PMNs .However, synovial fluid WBC count is not always increased in SGAB IAI, andwhen elevated, their numbers are similar to that seen in more virulentmicroorganisms . In 3.6C. acnes and C. avidum, with C. avidum causing a more robust immune response. Renz et al. (2018a) reported that inflammation was seen in peri-implant tissue in 100 % of IAI caused by C. avidum, but when cases of C. acnes were included in the evaluation, the overall positivity dropped to 67 % . Histopathological examinations of intraoperative peri-implant tissue samples are frequently negative for the presence of neutrophils, with a positivity of only about 17 %–50 % in C. acnes-associated PJI .Histopathological examination revealing the presence of neutrophils is animportant criterion in the overall diagnosis of PJI. In the 2021 EBJISdefinition of PJI, the presence of C. acnes-specific antibodies on tissue samples taken from patients undergoing primary shoulder surgery or arthroscopy for the first time and detected C. acnes intracellularly within stromal cells and macrophages . While the results of their study point towards C. acnes being a commensal in the shoulder, immunohistochemistry can also be potentially used to diagnose SGAB IAI with histopathology.Interestingly, Hudek et al. (2021) used immunohistochemistry with 3.7Microbiology remains the most important clinical entity in IAI as this,besides confirming the diagnosis , also provides apotential antibiogram to help guide the clinician in the adjuvant antibiotictreatment following surgery. The methods can be culture dependent orculture independent. However, especially concerning SGAB IAI there, are manyaspects to take into consideration for the clinician, as SGAB by naturedemands sophisticated processing not always undertaken in an everydayclinical setting, unless the clinician is acutely aware of the potentialpresence of SGAB as the causative organism.3.7.1Culture-dependent methods are relatively cheap and readily available in anyclinical microbiology laboratory. The success of culture-dependent methodsdepends on several factors, e.g. the nature of the organism to beisolated, the quality, type and number of specimens collected, andconditions and duration of incubation . Samples for microbiological diagnosis of IAI can be obtained preoperatively or intraoperative, as aspirations or biopsies, but also following implant subjected to sonication . In case of culture-negative PJI, culture-independent methods, such as next-generation sequencing (NGS), might be a useful addition to identify the causative SGAB .C. avidum IAI with one study showing the growth of this bacterium in preoperative aspiration fluid in 14 out of 15 cases . It has been found that C. acnes IAI culture of synovial/peri-implant fluid was not diagnostically accurate and showed low sensitivity compared to sonication fluid and peri-implant tissue . As in our case, culture-negative aspirations based on standard culture methods, with clear indications of infections based on synovial biomarkers, could indicate the presence of SGAB as the causative organism.Aspiration appears most useful in C. acnes, while S. aureus and coagulase-negative staphylococci (CoNS) would need just 3 and 4 samples, respectively . But with the increase in number of samples comes a theoretic increase in false positive cultures due to contamination. The specific aspects in relation to SGAB IAI need furtherevaluation.Culture of tissue samples is not just one of the oldest but also one of themost important methods in the diagnosis of IAI . The method ofcollection and the number of samples collected can affect the cultureresults. To optimize the chance of culturing bacteria, antibiotic pause 2 weeks preoperatively and prophylactic antibiotics withheld until the samples are collected are often applied, although the value in SGAB IAI has not been investigated . Multiple samples, also more than normal, may be required in SGAB due to a combination of low bacterial burden and uneven distribution of bacteria in the peri-implant tissues, as well as the risk of contamination in the processing of the samples . The current IDSA guidelines recommend at least three and optimally five or six samples with two positive cultures for a definitive diagnosis . However, a larger number of samples may be required for SGAB which have a lower rate of positive culture . Kheir et al. (2018) calculated that to get two positive cultures the average number of samples required would be 10 for C. acnes IAI . Conversely, the use of sonication fluid specimens was found to be inferior to the use of peri-implant tissue specimens in the detection of C. acnes in spinal implant infections .Since the introduction of sonication of removed implants in the 1990s by Tunney et al. (1998)and further improvements by Trampuz et al. (2007), microbial detection in sonication fluid culture has become widely adopted. Sonication is now incorporated in the IDSA and EBJIS guidelines for diagnosis of PJI . Like other IAI-associated bacteria, SGAB have been shown to form biofilms on medical devices and sonication helps to dislodge these biofilms, making it easier to culture the bacteria . Moreover, in patients with prior antibiotic therapy, sonication fluid specimens have shown to give more sensitive culture results than tissue specimens . For IAI caused by anaerobes, the culture of sonication fluid appears more sensitive than periprosthetic tissue samples . Yet, several studies could not find any advantage of sonication fluid over tissue specimens in C. acnes can take anywhere from 6 to 14 d or longer to grow . Incubation for 14 d seems to be the current standard for SGAB IAI , though other studies have used 21 d  and even 28 d . The need for prolonged incubation times must be considered against the increased risk of detection of contaminants with longer incubation periods. The number of bacterial colonies  that is cultivated is an important criterion to distinguish a true infection from possible contamination, and this topic is not evaluated for SGAB IAI. In sonication fluid different diagnostic CFU cut-offs , and these could possibly affect the culture results too. Culture media used for the growth of anaerobic bacteria vary among studies. Anaerobic sheep blood agar  and Columbia blood agar  were the most commonly used solid media, while thioglycolate broth  was the most commonly used liquid media. In addition, automated culture systems, like BACTEC or BacT/Alert, which are routinely used for blood culture and usually have the advantage of shorter time to positivity compared to conventional methods, were also used in some studies . However, no consensus on the choice of media for SGAB exists, which makes evaluation of SGAB IAI a difficult task, as these IAIs can be potentially in an everyday clinical setting. The duration of cultivation is another important factor to consider, when it comes to detection of SGAB. Prolonged incubation of SGAB is usually required compared to other organisms. Previous studies have shown that while most bacteria causing orthopaedic infections were isolated within 1 to 5 d, 3.7.2Culture-independent methods may have an important role in diagnosis of IAI,when other diagnostic tests are inconclusive, e.g. in the case of fastidious, slow-growing, or viable but non-culturable bacteria, and inpatients with prior antibiotic therapy . Commonly used culture-independent methods include polymerase chain reaction (PCR)-based methods such as species-specific PCR, multiplex PCR, and 16S ribosomal RNA (rRNA) PCR and next-generationsequencing. The clinical downside to culture-independent methods is the lackof an antibiogram in the individual case.C. acnes PCR assay, which amplifies a region of the C. acnes 16S rRNA gene. The application of this C. acnes PCR assay to sonication fluid was compared with the results from sonication fluid culture. The PCR assay was able to detect only six of the nine C. acnes-positive cultures . The use of multiplex PCR assays that allow the simultaneous detection of multiple species of choice have yielded conflicting results. Morgenstern et al. (2018) used multiplex PCR and found that synovial fluid multiplex PCR was superior to culture for the detection of hip and knee PJI due to low virulent organisms (not SGAB) and gave earlier results (5 h versus up to 14 d) . However, other studies found that multiplex PCR of sonication fluid detected fewer pathogens compared to periprosthetic tissue culture and sonication fluid culture and missed several low virulent organisms, including SGAB (Cutibacterium spp. and Finegoldia magna) . Bemer et al. (2014) found that the sensitivity of 16S rRNA gene PCR assay was low for C. acnes, with only 11 % of C. acnes and 72 % of CoNS infections being detected by PCR, compared with 92 % and 100 % of S. aureus and streptococci, respectively . The role of PCR based methods in SGAB IAI needs further evaluation. Amplicon next-generation sequencing (aNGS) or metagenomic next-generation sequencing (mNGS) have not been used, clinically, in the past for the diagnosis of IAI but is increasingly used in research on IAI. Its applicability is currently limited due to high costs and the need for extensive bioinformatics analyses but may have a future genuine clinical value in SGAB IAI. It involves DNA or RNA extraction, PCR amplification of target region (aNGS), enrichment of bacterial DNA or RNA (mNGS), library preparation, sequencing, and bioinformatics analysis . The analysis can be targeted in aNGS, which involves the amplification of specific genomic regions of believed value or untargeted in mNGS . The details and protocols of the individual steps can vary between individual laboratories, as these are currently at an experimental level. Next-generation sequencing analysis can be performed on any sample that yields sufficient nucleic acid . Wang et al. (2020a) found in a study of 24 culture-negative PJIs that mNGS was able to detect rare pathogens and fastidious bacteria like Mycoplasma hominis, F. magna, and P. micra, which were clinically believed to be the causative organisms . Wang et al. (2020b) found that the sensitivity of mNGS was significantly higher than the sensitivity of standard culture method, but not different to PCR assays . Weaver et al. (2019) found in joint fluid from seven PJI cases that mNGS was able to detect more species including C. acnes and also was superior for the detection of polymicrobial infections compared to standard culture . Namdari et al. (2019) found poor correlation between mNGS and culture in the detection of shoulder PJI .The usefulness of PCR assays in IAI is debated. Sampedro et al. (2010) developed aspecies-specific 4Cutibacterium spp. SGAB other than Cutibacterium species present with similar diagnostic challenges because of their similar clinical, imaging, laboratory, and microbiological findings, but only a limited number of studies focus on these SGAB in particular.Most studies mentioned in this review investigated the diagnostic challengesand frequencies of PJI due to Another limitation of the review is the underrepresentation of non-PJI IAI,since only a few studies focus on non-PJI IAI. This could be due to a lack ofdefinitive diagnostic criteria for non-PJI IAI. But SGAB have been reportedfrom IAI other than PJI, and their role in these infections should beinvestigated in more detail in future studies.5The presented case and review are in our opinion a clear example of thedifficulties that SGAB IAIs present to orthopaedic surgeons, infectiousdisease specialists, and clinical microbiologists in performing best-practice of care for patients. Currently, a high degree of clinicalsuspicion based on up-to-date knowledge of SGAB is the only factor that canguide the clinician. Future research into diagnosing SGAB IAI, as specifiedabove, is unquestionably warranted.


Based on practical experience, a systematic approach to conversion of ileal J-pouches into continent ileostomies is developed by defining three types of conversion surgery, each with two subtypes. Type 1 refers to conversion without pouch reconstruction, type 2 to partial pouch reconstruction, and type 3 to complete pouch reconstruction. The subdivisions (a and b) take into account whether the afferent loop of the former pelvic pouch (a) or a higher ileal/jejunal segment of the small intestine (b) is used in conversion and/or reconstruction. The six resulting surgical variants are shown in schematic illustrations with accompanying descriptions of technical details to provide the specialized surgeon with comprehensive technical guidance. The preferred method of proctocolectomy is ileoanal pouch surgery [ileal pouch–anal anastomosis (IPAA)]. It has replaced its precursor, continent ileostomy (CI), because unlike CI, it preserves the normal defecation route . The comType 1: simple conversion (without pouch reconstruction)Type 2: partial pouch reconstruction requiredType 3: complete reconstruction of a new CI requiredOn the basis of the first criterium (necessity and extent of pouch reconstruction), three main types of conversion are defined:a: Use of the afferent loopb: Transposition of oral ileum or jejunumAccording to secondary criteria , two subtypes are defined:Type 1a: nipple valve out of afferent loopThis is the classic standard conversion. It can always be used in cases where the existing J-pouch is worth preserving and its capacity is sufficient.Type 1b: nipple valve out of transposed higher ileum or jejunumThis is the classic standard design of the nipple valve. As the simplest technique, it is suitable in cases where the afferent loop is morphologically intact Fig. .Type 1b:In cases where the lumen of the afferent loop is too narrow (precluding intussusception) or too wide , and/or in case of scarring or inflammatory or fibrodesmoid changes, it is advisable to move to a higher segment of the small intestine and transpose it. In this case, the afferent loop can remain in continuity if there is no clinically relevant obstruction of the passage prior to surgery Fig. .Fig. 1CoType 2a: nipple valve plus pouch augmentation out of the afferent loopThere are two situations in which the J-pouch should be reconstructed or augmented. First, in cases of significant adhesions in the small pelvis, one of the two limbs of the J-pouch may be so injured during mobilization that it must be resected. These are usually patients in whom the indication for conversion results from the sequelae of septic complications following IPAA surgery. On the other hand, there are cases in which, after injury-free mobilization, the pouch capacity proves insufficient. These are often conversion candidates who were plagued by excessive evacuation frequency after IPAA surgery that could not be influenced by any measure.Type 2b: nipple valve plus pouch augmentation out of a transposed higher ileal or jejunal segmentThis is the standard reconstruction/augmentation in cases where the afferent loop is suitable for nipple valve construction Fig. .Type 2b:The indication for or field of application of this variant corresponds to the conditions described for type 1b Fig. .Fig. 3CoType 3a: new CI out of neoterminal ileumIn rare cases , the J-pouch is non-salvageable. If no contraindications for the construction of a second pouch are present, complete new construction of the CI can be performed.Type 3b: new CI out of transposed higher ileum or jejunumThis is the standard new construction of CI in cases where the afferent loop is morphologically suitable Fig. .Type 3b:This is a reserve method for reconstruction of the CI. It can be used in cases with afferent loop conditions, as described in 1b. This variant is particularly suitable in Crohn's disease (CD), since the jejunum is often spared from recurrences of inflammation in this underlying disease for the rest of the patient's life  Fig. 6)6).Fig. 5We focus on the various modifications of an interesting surgical procedure and the rationale behind it, not on the clinical results. We successfully performed a total of 26 surgeries using all six surgical variants between 1988 and 2015. Publication of the clinical results is underway. The emphasis herein is thus on the technical details. We assume that the corresponding schematic illustrations are largely self-explanatory for the specialized surgeon. Nevertheless, surgical implementation of salvage operations is always challenging and sometimes difficult [In selected cases, CI is worth considering and offers the advantage of complete control over fecal evacuation, with a much better quality of life (QoL) compared to conventional ileostomy , 6. ConsFrom a technical point of view, first and foremost, the pouch should be dissected from the pelvis as atraumatically as possible. Minor damage can be repaired while preserving the pouch . HoweverThese approaches, categorized into three primary types, each with two secondary subtypes, take into account all situations occurring in clinical practice. Moreover, it has been shown that categorizing the approaches is very helpful from a didactic perspective. Critics may argue that this is a sophistical over-differentiation, and that the complexity of the described variants could lead to increased complications.The systematic derivation of technical variants of conversion surgery expands the surgical armamentarium of the specialized surgeon to all underlying conditions encountered in practice. Thus, it is at least theoretically possible to save more patients with failed IPAA from the fate of a conventional ileostomy. Practical feasibility requires further evaluation in larger controlled studies.


Physical activity (PA), associated with all-cause mortality, morbidity, and healthcare costs, improves vitamin D absorption, immune response, and stress when completed outdoors. Rural communities, which experience PA inequities, rely on trails to meet PA guidelines. However, current trail audit methods could be more efficient and accurate, which geospatial video may support. Therefore, the study purpose was (1) to identify and adopt validated instruments for trail audit evaluations using geospatial video and a composite score and (2) to determine if geospatial video and a composite score motivate (influence the decision to use) specific trail selection among current trail users. Phase 1 used a mixed-method exploratory sequential core design using qualitative data, then quantitative data for the development of the Spatial-temporal Trail Audit Tool (STAT). Geospatial videos of two Northeast Ohio trails were collected using a bicycle-mounted spatial video camera and video analysis software. The creation of STAT was integrated from Neighborhood Environment Walkability Scale (NEWS), Walk Score, and Path Environment Audit Tool (PEAT) audit tools based on four constructs: trail accessibility, conditions, amenities, and safety. Scoring was determined by three independent reviewers. Phase 2 included a mixed-method convergent core design to test the applicability of STAT for trail participant motivation. STAT has 20 items in 4 content areas computing a composite score and was found to increase trail quality and motivation for use. STAT can evaluate trails for PA using geospatial video and a composite score which may spur PA through increased motivation to select and use trails. Physical activity (PA) is associated with a reduction in all-cause mortality, morbidity, and associated healthcare costs ,2. PhysiA large number of adults do not meet PA recommendations due to inequities in access to safe environments for PA . Some ofThe socio-ecological model (SEM) includes domains that impact PA, including individual, social/intrapersonal, community/environment , and policy, needed to address complex challenges in rural communities. This better enables the promotion of PA across all the socio-ecological domains as having accessible, highly rated trails is shown to increase PA in rural populations ,11,13. SIn addition to increased access and use, engaging in trail PA provides the additional benefits of being outdoors. These benefits include vitamin D absorption and additional immune response and stress reduction ,17. The Trail quality is currently assessed through audit tools designed to measure trail use facilitators and barriers. Facilitators include groomed trail conditions, adequate lighting, mixed views , and trailside amenities  ,19. BarrGeospatial video may assist with trail quality measures and trail use collection methods as it captures both quality and use of PA access points, such as parks and trails, by combining Global Positioning Systems (GPS) with video. Mills et al. (2010)  developeTrail quality and use data can be collected more efficiently by attaching the camera to a bicycle, rather than walking the trails, and archived to allow multiple researchers or practitioners to audit locations over multiple time periods . This reCurrent trail audit methods could be more efficient, accurate, and especially helpful in rural areas as having accessible, highly rated trails is shown to increase PA in rural populations. Using geospatial video with a redesigned audit tool may result in better audits and lead to improved PA interventions. Therefore, the purpose of this was (1) to identify and adopt validated instruments for trail audit evaluations using geospatial video and a composite score and (2) to determine if geospatial video and a composite score motivate (influence the decision to use) specific trail selection among physically active adults.To create and validate the final quantitative trail quality and use instrument, STAT, this study was designed as a 2-phase mixed-methods study. Please see Phase 1, mixed-methods exploratory sequential core design, consisted of 3 steps. The first step was to collect qualitative data in the form of a geospatial trail video. The second step was to use previously validated quantitative built environment trail audit tools to create STAT. The third step integrated the qualitative and quantitative data to revise STAT. The rationale for this approach was for the development of STAT , and theAs seen in To create STAT, content analysis of validated trail audit tools was conducted by adopting previous applications of geospatial video ,28. ThreNEWS, developed in 2002 by Dr. Sallis, measures residents’ perception of neighborhood design features , related to PA, within their local area . NEWS adWalk Score, developed in 2007 by Herstas, company Chief Executive Officer , is a prFinally, PEAT was developed in 2006 by Troped, Cromley, Fragala, Melly, Hasbrouck, Gortmaker, and Brownson to assess the physical characteristics of community trails and paths, including their design, amenities, and aesthetics . PEAT haBeginning with validated question content from the original NEWS survey and thereafter incorporating elements of Walk Score and PEAT, researcher M.N. and authors N.C. and C.S. compiled a list of content relevant to physical trail conditions from which the language of these selected questions was later modified to address these concerns specifically. After an initial list was outlined, N.C., M.N. and C.S. then reviewed the spatial video and added additional question content evoked from the viewing. Each reviewer’s questions were again compiled and organized into categories, which were based upon the existing built environment tool categories and question themes that occurred naturally.STAT composite scores were calculated from 0 to 100 to produce a general trail composite score by adding together the 4 content areas of access, conditions, amenities, and safety. Within the content areas, there were 20 items that used a 0 to 5, 6-point Likert Scale in which 0 equals “not at all” and 5, “yes, very much”. An additional composite score was produced for the low- and high-intensity PA subsets, ranging from 0 to 25, by adding together scores from items using a 0 to 5, 6-point Likert Scale as well.Following the initial audit tool adoption and construction, STAT was reviewed by two experts in built environment research and one in research design and survey methods, respectively, to provide face validity and identify potential content gaps. Following this input, the researchers integrated the qualitative and quantitative data by reviewing the trail geospatial video, using STAT to conduct an audit of the trails using the video, and revised STAT based on the experts’ feedback and trail audit.Institutional Review Board approval was obtained for human subjects research from the first author’s university (protocol code 16-597). Phase 2, convergent core design, consisted of steps 4 and 5 in the study. Step 4 simultaneously collected qualitative (focus group) and quantitative (online survey) data about the applicability and usability of STAT. Step 5 integrated and compared the qualitative and quantitative data to revise STAT. The rationale for this approach is that this allowed the researchers to compare, corroborate, and examine facets of STAT through triangulation and convergence of the data, which developed a more complete picture and tested the applicability and usability of STAT ,25.A convenience sample of participants, including close to equal representation of males and females, was then recruited using email from self-identified physically active participants at the first author’s university to join the focus group. Already physically active adults were recruited because they were familiar with the access, conditions, amenities, and safety of PA locations that tend to increase their selection of specific locations for PA. Therefore, using already active people provides clear insights into how STAT will work, which researchers and practitioners can use to improve the trails and increase the probability that those not meeting physical activity guidelines will be encouraged to use the trails. A semi-structured focus group was chosen to elicit participants’ thoughts and perceptions of STAT through intra- and inter-personal conversations for more open dialog supplementing the STAT survey in step 4 . MembersParticipants were given a copy of the STAT items and constructs, asked to review and then share which items and constructs were important for selecting a trail for exercise, items they would change or add to help them select a trail, and what was most important in selecting a trail for exercise. Next, participants were asked to watch a trail video played for them at the focus group. After watching the video, participants were asked if the video, specific categories of items, or a combination would help them determine whether or not they would select a trail for exercise and if having any of this information would motivate them to do so. Finally, participants were asked about their trail use and PA. The focus group discussion was transcribed, and focus group participants were asked to record notes on the copy of the STAT items, which included a copy of the focus group questions to assist in validating responses.After all focus groups were completed, researcher M.N., and authors N.C. and C.S. transcribed and de-identified files. The transcripts were entered into QSR International’s NVivo 11 qualitative data analysis software and analyzed using Saldaña’s (2016)  evaluatiThe survey included STAT items and participants were asked to rate each item for importance of selecting a trail for exercise using a Likert scale with 0 being not at all to 5 being very much. Participants were also asked which items they would change or add to help them select a trail, and what item was most important to them when selecting a trail for exercise. Next, participants were asked to watch a trail video linked to the survey. After watching the video participants were asked if the video, specific categories of items, or a combination would help them determine whether they would select a trail for exercise and if having STAT information would motivate them to do so, again, using a Likert scale with 0 being not at all to 5 being very much. Finally, participants were asked about their trail use PA, using the valid and reliable International Physical Activity Questionnaire (IPAQ) ,38, and The final STAT was created from the integration of the qualitative and quantitative data collected in step 4. This integration was completed by analyzing patterns between focus group and survey data to compare findings from the qualitative and quantitative data . Data weAfter reviewing NEWS, Walk Score, and PEAT audit tools, the researchers pulled content areas from these tools that served as a valid, theoretical basis including four constructs: (1) trail accessibility, (2) trail conditions, (3) trail amenities, and (4) trail safety. Constructs from the three validated instruments that could not be captured using the video were excluded from survey construction. These include (1) types of neighborhood residences; (2) stores, facilities, and other neighborhood amenities; and (3) neighborhood satisfaction. Constructs adopted and modified include (4) safety from traffic, and (5) safety from crime; the latter serving as a basis for STAT’s trail safety content. Please see These validated instruments’ constructs were adopted based on what the researchers could capture using the video from which STAT was created and comprised of 20-items measuring trail quality. Trail audit tools also cannot archive or share collected data. Therefore, in conjunction with the adopted audit tool (STAT), a video-based composite score was calculated using geospatial techniques. The researchers determined that a geospatially enhanced instrument, combining items from three validated built environment audit tools, was most appropriate based on the ability to measure the items using geospatial techniques to archive and therefore share the collected data.A composite score was calculated by adding together items from 6-point Likert scales. The scales included a not applicable inclusion (0), allowing for greater generalizability without devaluation of the composite score since (1) as the lowest option assigns value to a score that should have no value. An additional composite score was produced for the low- and high-intensity PA subsets, ranging from 0 to 25.During step 3, STAT was tested using the geospatial video collected in step 1. While researcher M.N. and authors N.C. and C.S. had different scores from each other (low interrater reliability), every score was within two points of each other, and consensus of the scores between the researcher and authors was determined and are reported in n = 30) were an average age of 44, mostly White, 53% male, $70,000 average income, and averaged about 70 min per trail session 4.2 days a week. Participants also indicated that the type of exercise they planned to do informed which trail they would select. Please see Participants from the focus group ”. The motivation was increased if “…the trail has elevation change, is at least somewhat technical”. Lastly, participants shared that they would use the video, amenity scoring, and condition items to help them determine a trail was appropriate for and supported the activity they were planning to do if they had access to the trail.Participants shared that exercise type determined their trail selection. Therefore, they would only be motivated to use a new trail if it was appropriate for and supported the activity they were planning to do. A participant shared that this included “n = 56) were slightly older than focus group participants with an average age of 46, similar to focus group participants in that they were mostly White and 55% male, with a higher average income of $74,000, and averaged more time, about 100 min per trail session, but less (2.3) days a week. Similar to the focus group participants, survey participants also indicated that the type of exercise they planned to do informed which trail they would select. Please see Participants from message boards  to identify and adopt validated instruments for trail audit evaluations using geospatial video and a composite score and (2) to determine if geospatial video and a composite score motivate (influence the decision to use) specific trail selection among physically active adults. Current methods of measuring the use of trails for PA includes counting users, as well as noting types of PA at trail heads or using infrared cameras, which are often ineffective and inaccurate. Therefore, using a bicycle-mounted camera to collect trail quality and use simultaneously is an effective, time-saving approach to data collection, enabling access to locations not reachable by car and providing a faster alternative to walking. An analysis of male versus female results was not completed since equal representation was ensured, and it was outside the scope of this research purpose. Outcomes of STAT can be used by a variety of stakeholders to increase trail quality and subsequent trail use.Geospatial methods and trail audits (such as STAT) have numerous uses. First, trail user motivation to select and use a trail based on video and the composite score would be strengthened. This may be helpful for researchers, practitioners, employee health coordinators, health insurance companies, and clinicians interested in health promotion efforts focusing on access to locations for exercise. Outdoor spaces may offer a more sustainable solution than costs and commute time associated with a traditional gym membership. Furthermore, safety and accessibility measures included in STAT should be considered alongside familiarity, distance to the location, physical ability, and socioeconomic access when referring patients to locations for PA . Thus, sAnother potential use for STAT is to monitor trail maintenance for park district paths at all levels  and community use over time. Neighborhoods could be evaluated for walking, cycling, and running for recreation and active transit, including shared or dedicated bike/pedestrian paths and safe routes to schools, parks, libraries, and other community locations. Grant writers applying to awards to enhance these locations  are often required to include path or trail audit results in their applications. STAT provides both these audit results and examples such as frame images and video links, enhancing grant applications.Additionally, community safety concerns could be addressed by matching city crime data with STAT’s trail safety perceptions. By testing trail safety perception with actual city crime data, community concerns can be addressed as needed through communication or police department surveillance as needed. Moreover, trail condition and amenity outcomes can be mapped and distributed to stakeholders and community members to increase the passage of park levies and other trail improvement and upkeep.Rural communities may find STAT particularly helpful as they manage more geographical space with fewer resources, including staff. These communities also tend to have poorer health outcomes, including PA , making The use of trails is associated with meeting PA recommendations in rural populations and at the same time, aside from one intervention, Heartland Moves (HM) , study sAlthough each of the three built environment audit tools  have been well-documented, tested, and validated, our adopted version of these tools, STAT, should undergo further validation among both diverse samples of trail users and practitioners, grant writers, and researchers. Additionally, while the development of STAT was both inspired by and constructed in conjunction with the use of geospatial video, the use of STAT is not limited to this technology. Geospatial video is, in general, a helpful dissemination tool and communication aid to share trail conditions and results with community stakeholders. While Plano Clark’s (2018)  exploratWhile Plano Clark’s (2018)  exploratThough geospatial video is instrumental for STAT, it likewise poses noteworthy temporal limitations. Captured geospatial data are physically limited to what was captured during the collection outing, characterized by the day and time of data collection. Since trail condition is variable depending upon the time of day, the time of year, and weather condition, temporality could alter the physical condition and, subsequent evaluation of the trail. As such, trail evaluations utilizing spatial video to administer STAT should collect multiple videos across a variety of times  and continue routinely to establish archival data. Finally, a central platform for geospatial video storage, retrieval, and dissemination would be helpful due to large file sizes.STAT increases efficiency and accuracy of assessing trail quality and use for PA using multiple levels of the SEM compared to current methods of counting users, noting types of PA at trail heads, and infrared cameras. Furthermore, since STAT uses geospatial video, a bicycle-mounted camera, it simultaneously collects trail quality, special temporal relationships and provides access to locations not reachable by car. Additionally, trail users indicated motivation to select and use trails based on STAT’s video and composite score. Therefore, a variety of stakeholders and communities may find STAT useful for increasing trail quality and use. Rural communities may especially benefit from STAT to promote PA across a variety of industries and environments. STAT results could be disseminated to address inequities through potential supports such as grants, levies, and other applications for funds.