bluuebunny/crossref_metadata_2025 huggingface dataset:
Census timing alters stage duration distributions in matrix population models
Authors: Okuyama Toshinori
Published: July 2019

Matrix population models are widely used to study the dynamics of stage‐structured populations. A census in these models is an event monitoring the number of individuals in each stage and occurs at discrete time intervals. The two most common methods used in building matrix population models are the prebreeding census and postbreeding census. Models using the prebreeding and postbreeding censuses assume that breeding occurs immediately before or immediately after the censuses, respectively. In some models such as age‐structured models, the results are identical regardless of the method used, rendering the choice of method a matter of preference. However, in stage‐structured models, where the duration of the first stage of life varies among newborns, a choice between the prebreeding and postbreeding censuses may result in different conclusions. This is attributed to the different first‐stage duration distributions assumed by the two methods. This study investigated the difference emerging in the structures of these models and its consequence on conclusions of eigenvalue and elasticity analyses using two‐stage models. Considerations required in choosing a modeling method are also discussed.
Traits of litter‐dwelling forest arthropod predators and detritivores covary spatially with traits of their resources
Authors: Brousseau Pierre‐Marc , Gravel Dominique , Handa I. Tanya
Published: July 2019

The functional trait approach proposes that relating traits of organisms within a community to variation in abiotic and biotic characteristics of their environment will provide insight on the mechanisms of community assembly. As traits at a given trophic level might act as filters for the selection of traits at another trophic level, we hypothesized that traits of consumers and of their resources covary in space. We evaluated complementary predictions about top‐down (negative) and bottom‐up (positive) trait covariation in a detrital food web. Additionally, we tested whether positive trait covariation was better explained by the Resource Concentration Hypothesis (i.e., most commonly represented trait values attract abundant consumers) or the Resource Specialization Hypothesis (i.e., resource diversity increases niche availability for the consumers). Macroarthopods were collected with pitfall traps over two summers in three forested sites of southern Quebec in 110 plots that varied in tree species composition. Six feeding traits of consumers (detritivores and predators) and six palatability traits of their resources (leaf litter and prey) were matched to assess spatial covariation. Trait matches included consumer biting force/resource toughness, detritivore mandibular gape/leaf thickness, predator/prey body size ratio, etc. Our results demonstrate for the first time a covariation between feeding traits of detritivores and palatability traits of leaf litter (31–34%), and between feeding traits of litter‐dwelling predators and palatability traits of potential prey (38–44%). The observed positive covariation supports both the Resource Concentration Hypothesis and Resource Specialization Hypothesis. Spatial covariation of consumer and resource traits provides a new tool to partially predict the structure of the detrital food web. Nonetheless, top‐down regulation remains difficult to confirm. Further research on top‐down processes will be undoubtedly necessary to refine our capacity to interpret the effect of biotic interactions on co‐distribution.
Formal [2+2+1] Synthesis of Tetrasubstituted Furans from Aldehydes, Acetylenedicarboxylates, and Acyl Compounds
Authors: Tateishi Keiichiro , Matsumoto Yuri , Saito Akio
Published: July 2019

A combination of 4‐picoline and Ph3P (or nBu3P) efficiently promotes a formal [2+2+1] synthesis of tetrasubstituted furans from aldehydes, acetylenedicarboxylates and acyl compounds under the metal‐free and mild conditions. The present method can be applied not only to acyl chlorides but also trifluoroacetic anhydride as the acyl compounds. These furan products were formed in moderate to excellent yields via O‐acylation of the α,β‐enone intermediates followed by intramolecular Wittig reaction. From the results of control experiments, it was found that 4‐picoline would serve as a promoter in the formation of both α,β‐enones and O‐acyl intermediates as well as a base for capturing of the generated acid.
Green synthesis of conductive polyaniline by Trametes versicolor laccase using a DNA template
Authors: Giacobbe Simona , Pezzella Cinzia , Della Ventura Bartolomeo , Giacobelli Valerio Guido , Rossi Manuela , Fontanarosa Carolina , Amoresano Angela , Sannia Giovanni , Velotta Raffaele , Piscitelli Alessandra
Published: July 2019

The green synthesis of highly conductive polyaniline by using two biological macromolecules, i.e laccase as biocatalyst, and DNA as template/dopant, was achieved in this work. Trametes versicolor laccase B (TvB) was found effective in oxidizing both aniline and its less toxic/mutagenic dimer N‐phenyl‐p‐phenylenediamine (DANI) to conductive polyaniline. Reaction conditions for synthesis of conductive polyanilines were set‐up, and structural and electrochemical properties of the two polymers were extensively investigated. When the less toxic aniline dimer was used as substrate, the polymerization reaction was faster and gave less‐branched polymer. DNA was proven to work as hard template for both enzymatically synthesized polymers, conferring them a semi‐ordered morphology. Moreover, DNA also acts as dopant leading to polymers with extraordinary conductive properties (∼6 S/cm). It can be envisaged that polymer properties are magnified by the concomitant action of DNA as template and dopant. Herein, the developed combination of laccase and DNA represents a breakthrough in the green synthesis of conductive materials.
Theoretical models for gas adsorption‐induced coal deformation under coal seam field conditions
Authors: Liu Huihui , Lin Baiquan , Yang Wei
Published: July 2019

Coal deformation caused by gas adsorption is a well‐known phenomenon and has played an important role in many engineering fields. For example, the bulk coal deformation induced by gas is a primary factor in coal and gas outbursts, and the changes in coalbed permeability are primarily determined by the evolution of the coal fracture volumetric strain during gas recovery. However, the current models of coal deformation induced by gas do not fully consider the coal seam field conditions or the deformation factors. To better fit coal seam field conditions and provide a basis for engineering applications, in this work, based on coal's physical structure, coal seam field conditions, the energy balance approach, poroelasticity, mathematical differentiation, and previous scholars' research results, the volumetric strain models of bulk coal, coal fracture, and coal matrix under coal seam field conditions are established. In addition, based on the analysis of the effect of gas pressure on coal deformation, the difference in gas pressure effects on the bulk coal deformation between experimental conditions and coal seam field conditions revealed that when the bulk coal deformation is tested in a laboratory, the gas pressure exerts a compressive effect on the bulk coal. However, under coal seam field conditions, the gas pressure has a swelling effect on the bulk coal. Additionally, gas pressure exerts an compression on the coal matrix and a swelling on the coal fracture under coal seam field conditions. At the end of the paper, the established models were analyzed and discussed from multiple perspectives. It was shown that the coal deformation models established in this paper are all accurate and reliable.
Identification of groundwater mean transit times of precipitation and riverbank infiltration by two‐component lumped parameter models
Authors: Le Duy Nguyen , Dung Nguyen Viet , Heidbüchel Ingo , Meyer Hanno , Weiler Markus , Merz Bruno , Apel Heiko
Published: July 2019

Groundwater transit time is an essential hydrologic metric for groundwater resources management. However, especially in tropical environments, studies on the transit time distribution (TTD) of groundwater infiltration and its corresponding mean transit time (mTT) have been extremely limited due to data sparsity. In this study, we primarily use stable isotopes to examine the TTDs and their mTTs of both vertical and horizontal infiltration at a riverbank infiltration area in the Vietnamese Mekong Delta (VMD), representative of the tropical climate in Asian monsoon regions.

Precipitation, river water, groundwater, and local ponding surface water were sampled for 3 to 9 years and analysed for stable isotopes (δ18O and δ2H), providing a unique data set of stable isotope records for a tropical region. We quantified the contribution that the two sources contributed to the local shallow groundwater by a novel concept of two‐component lumped parameter models (LPMs) that are solved using δ18O records.

The study illustrates that two‐component LPMs, in conjunction with hydrological and isotopic measurements, are able to identify subsurface flow conditions and water mixing at riverbank infiltration systems. However, the predictive skill and the reliability of the models decrease for locations farther from the river, where recharge by precipitation dominates, and a low‐permeable aquitard layer above the highly permeable aquifer is present. This specific setting impairs the identifiability of model parameters. For river infiltration, short mTTs (<40 weeks) were determined for sites closer to the river (<200 m), whereas for the precipitation infiltration, the mTTs were longer (>80 weeks) and independent of the distance to the river.

The results not only enhance the understanding of the groundwater recharge dynamics in the VMD but also suggest that the highly complex mechanisms of surface–groundwater interaction can be conceptualized by exploiting two‐component LPMs in general. The model concept could thus be a powerful tool for better understanding both the hydrological functioning of mixing processes and the movement of different water components in riverbank infiltration systems.
Assessing the performance of a physically based hydrological model using a proxy‐catchment approach in an agricultural environment
Authors: Escobar‐Ruiz Veronica , Smith Hugh G. , Blake William H. , Macdonald Neil
Published: July 2019

Physically based models are useful frameworks for testing intervention strategies designed to reduce elevated sediment loads in agricultural catchments. Evaluating the success of these strategies depends on model accuracy, generally established by a calibration and evaluation process. In this contribution, the physically based SHETRAN model was assessed in two similar U.K. agricultural catchments. The model was calibrated on the Blackwater catchment (18 km2) and evaluated in the adjacent Kit Brook catchment (22 km2) using 4 years of 15 min discharge and suspended sediment flux data. Model sensitivity to changes in single and multiple combinations of parameters and sensitivity to changes in digital elevation model resolution were assessed. Model flow performance was reasonably accurate with a Nash–Sutcliffe efficiency coefficient of 0.78 in Blackwater and 0.60 in Kit Brook. In terms of event prediction, the mean of the absolute percentage of difference (μAbsdiff) between measured and simulated flow volume (Qv), peak discharge (Qp), sediment yield (Sy), and peak sediment flux (Sp) showed larger values in Kit Brook (48% [Qv], 66% [Qp], 298% [Sy], and 438% [Sp]) compared with the Blackwater catchment (30% [Qv], 41% [Qp], 106% [Sy], and 86% [Sp]). Results indicate that SHETRAN can produce reasonable flow prediction but performs less well in estimation of sediment flux, despite reasonably similar hydrosedimentary behaviour between catchments. The sensitivity index showed flow volume sensitive to saturated hydraulic conductivity and peak discharge to the Strickler coefficient; sediment yield was sensitive to the overland flow erodibility coefficient and peak sediment flux to raindrop/leaf soil erodibility coefficient. The multiparameter sensitivity analysis showed that different combinations of parameters produced similar model responses. Model sensitivity to grid resolution presented similar flow volumes for different digital elevation model resolutions, whereas event peak and duration (for both flow and sediment flux) were highly sensitive to changes in grid size.
Blood circRNAs as biomarkers for the diagnosis of community‐acquired pneumonia
Authors: Zhao Tian , Zheng YaLi , Hao DengZai , Jin Xuesong , Luo QiongZhen , Guo YaTao , Li DaiXi , Xi Wen , Xu Yu , Chen YuSheng , Gao ZhanCheng , Zhang Yan
Published: July 2019

Circular RNAs (circRNAs) have been reported as effective diagnostic and therapeutic biomarkers in many diseases, but the potential of using this easy‐to‐monitor and highly stable materials for diagnosing Community‐acquired pneumonia (CAP) remains unexplored. Here, aiming to identify potential CAP‐related circRNAs in peripheral blood and seeking to deepen the understanding of how circRNA‐miRNA‐mRNA regulatory networks may contribute to CAP, we applied microarrays profiling analysis and identified 8296 differentially expressed (DE) circRNAs between patients with CAP (n = 6) and healthy controls (n = 6). Subsequently, we validated the accumulation trends for the top 100 DE circRNAs based on qPCR in an independent validation cohort (30 patients vs 30 controls), and ultimately identified a panel of four circRNAs that perform extremely well as sensitive and specific biomarkers for diagnosing CAP: hsa_circ_0018429 (area under the curve [AUC] = 0.8216), hsa_circ_0026579 (AUC = 0.7733), hsa_circ_0125357 (AUC = 0.7730), and hsa_circ_0099188 (AUC = 0.6978); combined as a panel (AUC = 0.8776). In addition, hsa_circ_0026579 exhibited good performance in differentiating viral from bacterial or mixed infection, with an AUC of 0.863. We also identified 10 miRNAs that most likely to interact with these four circRNAs, and then predicted 205 mRNA target genes. The KEGG pathway enrichment analysis suggested highly plausible functional implications related to inflammation and to virus‐infection‐related signaling pathways (such as HTLV‐1 infection and hepatitis B infection). Thus, we generated a genetic network of potential CAP‐related regulatory interactions that should inform future hypothesis‐driven research into the causes and potential treatment of this widespread and frequently fatal disease.
Cancer stem cells: A review from origin to therapeutic implications
Authors: Atashzar Mohammad Reza , Baharlou Rasoul , Karami Jafar , Abdollahi Hamid , Rezaei Ramazan , Pourramezan Fatemeh , Zoljalali Moghaddam Seyed Hamid
Published: July 2019

Cancer stem cells (CSCs), also known as tumor‐initiating cells (TICs), are elucidated as cells that can perpetuate themselves via autorestoration. These cells are highly resistant to current therapeutic approaches and are the main reason for cancer recurrence. Radiotherapy has made a lot of contributions to cancer treatment. However, despite continuous achievements, therapy resistance and tumor recurrence are still prevalent in most patients. This resistance might be partly related to the existence of CSCs. In the present study, recent advances in the investigation of different biological properties of CSCs, such as their origin, markers, characteristics, and targeting have been reviewed. We have also focused our discussion on radioresistance and adaptive responses of CSCs and their related extrinsic and intrinsic influential factors. In summary, we suggest CSCs as the prime therapeutic target for cancer treatment.
tiRNAs: A novel class of small noncoding RNAs that helps cells respond to stressors and plays roles in cancer progression
Authors: Tao En‐Wei , Cheng Wing Yin , Li Wei‐Lin , Yu Jun , Gao Qin‐Yan
Published: July 2019

tRNA‐derived stress‐induced RNAs (tiRNAs), important components of tRNA‐derived fragments, are gaining popularity for their functions as small noncoding RNAs involved in cancer progression. Under cellular stress, tiRNAs are generated when mature tRNA is specifically cleaved by angiogenin and suggested to act as transducers or effectors involved in cellular stress responses. tiRNAs facilitate cells to respond to stresses mainly via reprogramming translation, inhibiting apoptosis, degrading mRNA, and generating stress granules. This review introduces the cellular biogenesis, molecular mechanisms, and biological roles of tiRNAs in stress response and disease regulation. A better understanding of their roles in regulating cancer may provide novel biomarkers or therapeutic targets for diagnosis and treatment.
Lipid phosphatase SHIP‐1 regulates chondrocyte hypertrophy and skeletal development
Authors: So Eui‐Young , Sun Changqi , Wu Keith Q. , Driesman Adam , Leggett Susan , Isaac Mauricio , Spangler Travis , Dubielecka‐Szczerba Patrycja M. , Reginato Anthony M. , Liang Olin D.
Published: July 2019

SH2‐containing inositol‐5′‐phosphatase‐1 (SHIP‐1) controls the phosphatidylinositol‐3′‐kinase (PI3K) initiated signaling pathway by limiting cell membrane recruitment and activation of Akt. Despite the fact that many of the growth factors important to cartilage development and functions are able to activate the PI3K signal transduction pathway, little is known about the role of PI3K signaling in chondrocyte biology and its contribution to mammalian skeletogenesis. Here, we report that the lipid phosphatase SHIP‐1 regulates chondrocyte hypertrophy and skeletal development through its expression in osteochondroprogenitor cells. Global SHIP‐1 knockout led to accelerated chondrocyte hypertrophy and premature formation of the secondary ossification center in the bones of postnatal mice. Drastically higher vascularization and greater number of c‐kit + progenitors associated with sinusoids in the bone marrow also indicated more advanced chondrocyte hypertrophic differentiation in SHIP‐1 knockout mice than in wild‐type mice. In corroboration with the in vivo phenotype, SHIP‐1 deficient PDGFRα + Sca‐1 + osteochondroprogenitor cells exhibited rapid differentiation into hypertrophic chondrocytes under chondrogenic culture conditions in vitro. Furthermore, SHIP‐1 deficiency inhibited hypoxia‐induced cellular activation of Akt and extracellular‐signal‐regulated kinase (Erk) and suppressed hypoxia‐induced cell proliferation. These results suggest that SHIP‐1 is required for hypoxia‐induced growth signaling under physiological hypoxia in the bone marrow. In conclusion, the lipid phosphatase SHIP‐1 regulates skeletal development by modulating chondrogenesis and the hypoxia response of the osteochondroprogenitors during endochondral bone formation.
Synthesis of Pyrimidine and Pyran Derivatives with the Related Systems and the Study of Their Behavior in the Liquid Solutions
Authors: El‐Sayed Refat , Katouah Hanadi A.
Published: July 2019

This study aims to synthesis of condensed and non‐condensed heterocyclic rings with long fatty chains as surface active biological compounds. 2‐Cyano‐3‐(dimethylamino)‐N‐octadecylacrylamide (5) was used to synthesize pyrimidine, pyran, and other condensed products by interacting with appropriate chemical reagents. These compounds were transferred to nonionic surface‐active agents by condensation with propylene oxide. The surface and biological properties showed that these compounds have a high solubility that helps them in easy absorption and adsorption with other compounds. In addition, they have a high ability to decrease the surface tension of the liquids, good wetting, and emulsification power, which can be used at different temperatures without losing their surface or biological properties and enable them for use in industrial and pharmaceutical purposes easily.
Phenotypic and functional changes in gamma delta T lymphocytes from HTLV-1 carriers
Authors: Cavalcanti De Albuquerque Raquel , Granato Alessandra , Silva Castro Isabela , Carvalho Torres Rafael , Santos Souza Flávia , Lima Marco Antonio , Celestino Bezerra Leite Ana Claudia , de Melo Espíndola Otávio , Echevarria-Lima Juliana
Published: July 2019

Human T-cell lymphotropic virus type-1 (HTLV-1) is the etiologic agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), which is a chronic inflammatory disease that leads to gradual loss of motor movement as a result of the death of spinal cord cells through immune mediated mechanisms. The risk to develop HAM/TSP disease positively correlates with the magnitude of HTLV-1 proviral load. Gamma-delta T lymphocytes have been recognized as important players in a variety of infectious diseases. Therefore, we have investigated interactions between HTLV-1 infection and γδ T lymphocytes during HAM/TSP. Similar frequencies of total γδ T lymphocytes and their Vγ9δ2+ and Vγ9δ2neg subpopulations were observed in HAM/TSP patients. However, T lymphocytes obtained from HTLV-1 carriers displayed significantly higher rates of spontaneous proliferation and NKp30 expression when compared to cells from uninfected donors. In addition, an important decrease in the frequency of granzyme B+ γδ T lymphocytes (approximately 50%) was observed in HAM/TSP patients. Higher proportion of IFN-γ+ γδ T lymphocytes was found in HTLV-1-infected patients, which positively correlated with the HTLV-1 proviral load in peripheral blood mononuclear cells. Collectively, our data indicates that HTLV-1 infection leads to phenotypic and functional changes in the population of γδ T lymphocyte population, suggesting that HTLV-1 infection modulates functions associated to these cells, which might be involved in controlling the infection or in the development of HTLV-1-associated diseases.
Service mix, market competition, and cost efficiency: A longitudinal study of U.S. hospitals
Authors: Ding Xin (David) , Peng Xiaosong (David) , Heim Gregory R. , Jordan Victoria S.
Published: July 2019

We examine the longitudinal impact of service mix on cost efficiency in U.S. acute care general hospitals. We propose two different dimensions of service mix, with the first dimension capturing internal emphasis on specific service lines (i.e., specialization) and the second dimension reflecting the deviation of a hospital from the average level of specialization for hospitals in the same service area (i.e., differentiation). We hypothesize that as the level of a hospital's specialization increases, hospital cost efficiency should improve at a decreasing rate. We also hypothesize that differentiation helps improve cost efficiency in competitive markets. Lastly, we examine whether acute care general hospitals can use service mix as an operational lever to improve cost efficiency when specialty hospitals are present in the same local markets. We find strong empirical support for the hypothesized relationships.
Shift in the timing of microvascular free tissue transfer failures in head and neck reconstruction
Authors: Sweeny Larissa , Topf Michael , Wax Mark K. , Rosenthal Eben L. , Greene Benjamin J. , Heffelfinger Ryan , Krein Howard , Luginbuhl Adam , Petrisor Daniel , Troob Scott H. , Hughley Brian , Hong Steve , Zhan Tingting , Curry Joseph
Published: July 2019

Objective

Analyze the cause and significance of a shift in the timing of free flap failures in head and neck reconstruction.

Study Design

Retrospective multi‐institutional review of prospectively collected databases at tertiary care centers.

Methods

Included consecutive patients undergoing free flap reconstructions of head and neck defects between 2007 and 2017. Selected variables: demographics, defect location, donor site, free flap failure cause, social and radiation therapy history.

Results

Overall free flap failure rate was 4.6% (n = 133). Distribution of donor tissue by flap failure: radial forearm (32%, n = 43), osteocutaneous radial forearm (6%, n = 8), anterior lateral thigh (23%, n = 31), fibula (23%, n = 30), rectus abdominis (4%, n = 5), latissimus (11%, n = 14), scapula (1.5%, n = 2). Forty percent of flap failures occurred in the initial 72 hours following reconstruction (n = 53). The mean postoperative day for flap failure attributed to venous congestion was 4.7 days (95% confidence interval [CI], 2.6–6.7) versus 6.8 days (CI 5.3–8.3) for arterial insufficiency and 16.6 days (CI 11.7–21.5) for infection (P < .001). The majority of flap failures were attributed to compromise of the arterial or venous system (84%, n = 112). Factors found to affect the timing of free flap failure included surgical indication (P = .032), defect location (P = .006), cause of the flap failure (P < .001), and use of an osteocutaneous flap (P = .002).

Conclusion

This study is the largest to date on late free flap failures with findings suggesting a paradigm shift in the timing of flap failures. Surgical indication, defect site, cause of flap failure, and use of osteocutaneous free flap were found to impact timing of free flap failures.

Level of Evidence

4 Laryngoscope, 130:347–353, 2020
Hierarchical and Spiral Polymer Structures: Direct Electrospinning on Porous Anodic Aluminum Oxide Templates
Authors: Liu Ying‐Hsuan , Chiu Yu‐Jing , Chen Jiun‐Tai
Published: July 2019

Electrospun fibers with hierarchical structures have attracted a great deal of attention because they have distinct properties, such as large specific surface areas and high surface area‐to‐volume ratios, and can be applied to various fields. Here, a simple and versatile method is demonstrated to prepare electrospun fibers with hierarchical structures by directly electrospinning poly(methyl methacrylate) (PMMA) solutions on porous anodic aluminum oxide (AAO) templates. Hierarchical PMMA structures with micro‐ and nanometer scales can be generated. The two length scales of the hierarchical structures can be independently controlled; the first length scale is controlled by the electrospinning conditions, and the second length scale is controlled by the pore sizes of the AAO templates. By adding water in the polymer solutions, the evaporation of the solvents and the whipping instability of the solution jets can be manipulated. Consequently, spiral and hierarchical structures can be obtained. This study opens a promising avenue in fabricating electrospun polymer fibers with hierarchical structures, which should have great potential in a variety of applications, such as filtration, diagnosis, and tissue regeneration.
Evaluation of GALNT16 polymorphisms to breast cancer risk in Chinese population
Authors: Wu Huangfu , He Guisheng , Song Tao , Zhang Yazhen , Chen Xiuxiu , Chen Huamin , Xiong Wei , Sun Chuanwei , Zhao Chaoyang , Chen Yunjing
Published: July 2019

Background

Polypeptide N‐acetylgalactosaminyltransferase 16 (GALNT16) is an N‐acetylgalactosaminyltransferase gene that alters protein O‐glycosylation, which plays a role in tumor development. This study aims to explore the association of eight GALNT16 polymorphisms with susceptibility to breast cancer (BC).

Methods

This case–control study included 563 BC patients and 552 age‐matched healthy controls from the Chinese Han population. The genotypes of GALNT16 polymorphisms were detected using the Agena MassARRAY. The relationship between GALNT16 polymorphisms and BC risk was evaluated using a chi‐squared test with an odds ratio (OR) and 95% confidence intervals (CI) under five genetic models.

Results

We observed that rs2105269 and rs72625676 were associated with higher BC risk in younger patients with age ≤51 (rs2105269, codominant: p = .006; recessive: p = .005 additive: p = .018; and allele: p = .012; rs72625676, codominant: p = .038; recessive: p = .037). For rs1275678 polymorphism, there was a significantly decreased risk of BC among elder patients (codominant: p = .017; dominant: p = .019; additive: p = .030; and allele: p = .029). Further analysis by clinical characteristics showed rs2105269 was associated with tumor size and lymph node metastasis.

Conclusion

Our study suggests that GALNT16 polymorphisms are associated with BC susceptibility in Chinese population.
Screening for Pediatric Malnutrition at Hospital Admission: Which Screening Tool Is Best?
Authors: Carter Laura E. , Shoyele Grace , Southon Sarah , Farmer Anna , Persad Rabin , Mazurak Vera C. , BrunetWood M. Kim
Published: July 2019

Background

Identifying children at malnutrition risk on admission to hospital is considered best practice; however, nutrition screening in pediatric populations is not common. The aim of this study was to determine which screening tool is able to identify children with malnutrition on admission to hospital.

Methods

A nurse administered 2 pediatric nutrition screening tools, Screening Tool for Risk on Nutritional Status and Growth (STRONGkids) and Pediatric Nutrition Screening Tool (PNST) to patients admitted to medicine and surgery units (n = 165). The Subjective Global Nutritional Assessment (SGNA) was then completed by a dietitian, blinded to the results of the screens. Sensitivity, specificity, and κ were calculated for both screening tools against the SGNA. A receiver operating characteristic (ROC) curve assessed alternate cutoffs for each tool. Length of hospital stay (LOS) was used to assess prospective validity.

Results

Using the recommended cutoffs, the sensitivity of STRONGkids was 89%, specificity 35%, and κ 0.483. The sensitivity of PNST was 58%, specificity 88%, and κ 0.601. Using adjusted cutoffs, PNST's sensitivity improved to 87%, specificity 71%, and κ 0.681, and STRONGkids specificity improved to 61%, sensitivity 80%, and κ 0.5. Children identified at nutrition risk had significantly longer LOS (P< 0.05).

Conclusion

This study showed neither tool was appropriate for clinical use based on published cutoffs. By adjusting the cutoffs using ROC curve analysis, both tools improved overall agreement with the SGNA without significantly impacting the prospective validity. PNST with adjusted cutoffs is the most appropriate for clinical use in this population.
Fabrication of open‐porous PCL/PLA tissue engineering scaffolds and the relationship of foaming process, morphology, and mechanical behavior
Authors: Wang Lixia , Wang Dongfang , Zhou Yiping , Zhang Yantao , Li Qian , Shen Changyu
Published: July 2019

Tissue engineering scaffolds should provide a suitable porous structure and proper mechanical strength, which is beneficial for the delivery of growth factor and regulation of cells. In this study, the open‐porous polycaprolactone (PCL)/poly (lactic acid) (PLA) tissue engineering scaffolds with suitable porous scale were fabricated using different ratios of PCL/PLA blends. At the same time, the relationship of foaming process, morphology, and mechanical behavior in the optimized batch microcellular foaming process were studied based on the single‐factor experiment method. The porous structures and mechanical strength of the scaffolds were optimized by adjusting foaming parameters, including the temperature, pressure, and CO2 dissolution time. The results indicated that the foaming parameters influence the cell morphology, further determine the mechanical behavior of PCL/PLA blends. When the PCL content is high, with the increase of temperature and time, the cell diameter and the elastic modulus increased, and the tensile strength and elastic modulus increased with the increase of the average cell size, and decreased as the increase of the cell density. While when the PLA content was high, the cell diameter showed the same trend, and the tensile strength and elastic modulus were higher, and the elongation at break was lower, and tensile strength and elastic modulus decreased with the increase of the average cell size and increased with the increase of cell density. This work successfully fabricated optimized porous PCL/PLA scaffolds with excellent suitable mechanical properties, pore sizes, and high interconnectivity, indicating the effectiveness of modulating the batch foaming process parameters.
Epoxy matrix composites reinforced with purified carbon nanotubes for thermal management applications
Authors: Chen Junjie , Gao Xuhui , Song Wenya
Published: July 2019

The role of carbon nanotube purification treatment as a means to improve the thermal properties of polymer matrix composites was investigated. Particular emphasis was placed on clarifying the processing‐property relationship in polymer composites for thermal management applications. The results indicated that purification treatment is critical to the thermal properties of derived polymer composites. Purification treatment can yield a twofold increase in composite thermal conductivity because of improved effectiveness in interfacial interaction and increased chemical purity of the filler. However, there is a trade‐off between the benefits and disadvantages associated with purification treatment, particularly when thermal and electrical properties are both concerned. Purification treatment gives rise to a sharp decrease in composite electrical conductivity by at least two orders of magnitude because of the lack of an effective percolating network. The effect of purification treatment on composite electrical properties is more significant than on its thermal properties.
Continuous‐time causal mediation analysis
Authors: Albert Jeffrey M. , Li Youjun , Sun Jiayang , Woyczynski Wojbor A. , Nelson Suchitra
Published: July 2019

While causal mediation analysis has seen considerable recent development for a single measured mediator (M) and final outcome (Y), less attention has been given to repeatedly measured M and Y. Previous methods have typically involved discrete‐time models that limit inference to the particular measurement times used and do not recognize the continuous nature of the mediation process over time. To overcome such limitations, we present a new continuous‐time approach to causal mediation analysis that uses a differential equations model in a potential outcomes framework to describe the causal relationships among model variables over time. A connection between the differential equation models and standard repeated measures models is made to provide convenient model formulation and fitting. A continuous‐time extension of the sequential ignorability assumption allows for identifiable natural direct and indirect effects as functions of time, with estimation based on a two‐step approach to model fitting in conjunction with a continuous‐time mediation formula. Novel features include a measure of an overall mediation effect based on the “area between the curves,” and an approach for predicting the effects of new interventions. Simulation studies show good properties of estimators and the new methodology is applied to data from a cohort study to investigate sugary drink consumption as a mediator of the effect of socioeconomic status on dental caries in children.
Validating effectiveness of safety requirements' compliance evaluation in process assessments
Authors: Varkoi Timo , Mäkinen Timo , Cameron Frank , Nevalainen Risto
Published: July 2019

Safety is the primary concern when developing systems containing software in the nuclear power domain. Process assessments are used to ensure quality of the development processes for safety‐critical systems. Regulators of the nuclear power industry have increased requirements concerning the systems development processes. Now, process assessments are integrated in the qualification of the systems and are expected to provide information not only based on the assessment model but also about the domain‐specific requirements. Therefore, a specific activity, compliance evaluation, was inserted into the assessment process to provide detailed information that supports analysis of the compliance to the domain standards. Compliance evaluation utilizes assessment findings to create evidence of the relevant domain‐specific requirements. The main purpose of this study is to validate effectiveness of compliance evaluation by analyzing assessment findings and their relation to the requirements of a safety‐critical domain. The analysis is based on representing the data in compliance evaluation reports as binary relations. The results of this analysis indicate that process assessment findings are also relevant when evaluating compliance to other sets of requirements. The results can significantly support the trustworthiness of the process assessment method and ensure effective use of process assessments.
Human-Computer Interaction in Physical Retail Environments and the Impact on Customer Experience: Systematic Literature Review and Research Agenda
Authors: Obermeier Gabriele , Auinger Andreas
Published: July 2019

Shopping in the traditional retail environment is increasingly being influenced by technologies enabling human-computer interaction. Scientists, as well as retailers, are interested in examining the effects of interactive in-store technologies on customer behavior. An abundance of researchers have examined customer acceptance of interactive technologies, but little is known about its effects on the customer’s experience and its consequences, such as satisfaction, loyalty, and purchase intention. Following the guidelines for a systematic literature review, this article gives an overview of empirical studies conducted on interactive technologies in traditional brick-and-mortar retail stores. Based on that review, this paper provides a research agenda for future work on interactive in-store technologies and their impact on customer experience and suggests possible research methods for empirical studies in the field of human-computer interaction.
Probing the holographic Fermi arc with scalar field: numerical and analytical study
Authors: Chakrabarti Sayan , Maity Debaprasad , Wahlang Wadbor
Published: July 2019

Abstract

Fermi arcs are disconnected contour of Fermi surface, which can be observed in pseudo-gap phase of high temperature superconductors. Aiming to understand this pseudo-gap phenomena, we study a holographic Fermionic system coupled with a massive scalar field in an AdS black hole background. Depending on the boundary condition on the scalar field mode, we discuss two possible scenarios. When the scalar condenses below a critical temperature T

c
, Fermi surface undergoes a transition from normal phase to pseudo-gap phase. Hence T

c
can be the reminiscent of well known cross over temperature T

*
in cuprate superconductor, below which pseudo-gap appears at constant doping. In the second scenario, the bulk scalar develops a non-normalizable profile at arbitrary temperature for non-zero source at the boundary. Therefore, we can tune the Fermi spectrum by tuning a dual source at the boundary. The dual source for this case can be the reminiscent of hole doping in the real cuprate superconductor. For both the cases we have studied Fermi spectrum and observed anisotropic gap in the spectral function depending on the model parameter and studied the properties of Fermi arcs across different phases.
$$ \mathcal{N} = 2 $$ gauge theories on unoriented/open four-manifolds and their AGT counterparts
Authors: Bawane Aditya , Benvenuti Sergio , Bonelli Giulio , Muteeb Nouman , Tanzini Alessandro
Published: July 2019

Abstract

We compute the exact path integral of

$$ \mathcal{N} = 2 $$

N

=
2

supersymmetric gauge theories with general gauge group on ℝℙ4 and a ℤ2-quotient of the hemi-S
4. By specializing to SU(2) superconformal quivers, we show that these, together with hemi-S
4 partition functions, compute Liouville correlators on unoriented/open Riemann surfaces. We perform explicit checks for Riemann surfaces obtained as ℤ2 quotients of the sphere and the torus. We also discuss the coupled 3d−4d systems associated to Liouville amplitudes with boundary punctures.
Increased ethanol tolerance associated with the pntAB locus of Oenococcus oeni and Lactobacillus buchneri
Authors: Liu Siqing , Skory Chris , Liang Xiaojin , Mills David , Qureshi Nasib
Published: July 2019

Lactobacillus buchneri and Oenococcus oeni are two unique ethanol-tolerant Gram-positive bacteria species. Genome comparison analyses revealed that L. buchneri and O. oeni possess a pntAB locus that was absent in almost all other lactic acid bacteria (LAB) genomes. Our hypothesis is that the pntAB locus contributes to the ethanol tolerance trait of these two distinct ethanol-tolerant organisms. The pntAB locus, consisting of the pntA and pntB genes, codes for NADP(H) transhydrogenase subunits. This membrane-bound transhydrogenase catalyzes the reduction of NADP+ and is known as an important enzyme in maintaining cellular redox balance. In this study, the transhydrogenase operon from L. buchneri NRRL B-30929 and O. oeni PSU-1 were cloned and analyzed. The LbpntB shared 71.0% identity with the O. oeni (OopntB). The entire pntAB locus was expressed in Lactococcus lactis ssp . lactis IL1403 resulting in an increased tolerance to ethanol (6%), butanol (1.8%) and isopropanol (1.8%) when compared to the control strain. However, the recombinant E. coli cells carrying the entire pntAB locus did not show any improved ethanol tolerance. Independent expression of OopntB and LbpntB in recombinant E. coli BL21(DE3)pLysS host demonstrated higher tolerance to ethanol when compared with a control E. coli BL21(DE3)pLysS strain carrying pET28b vector. Ethanol tolerance comparison of E. coli strains carrying LbpntB and OopntB showed that LbpntB conferred higher ethanol tolerance (4.5%) and resulted in greater biomass, while the OopntB conferred lower ethanol tolerance (4.0%) resulted lower biomass. Therefore, the pntB gene from L. buchneri is a better choice in generating higher ethanol tolerance. This is the first study to uncover the role of pntAB locus on ethanol tolerance.
Outcome of children with systemic rheumatic diseases admitted to pediatric intensive care unit
Authors: Al-Mayouf Sulaiman M , Fallatah Rehab , Al-Twajery Mohammed , Alayed Tareq , Alsonbul Abdullah
Published: July 2019

Objective

To report the outcome of children with rheumatic diseases admitted to pediatric intensive care unit (PICU) in a tertiary hospital.

Methods

Database from PICU and pediatric rheumatology section used to retrieve all candidate patients admitted to PICU from June 2000 to December 2017. Medical records of all enrolled patients reviewed for diagnosis, organ involvement, reason of PICU admission, the length of stay, and outcome.

Results

Twenty-five patients (17 female, 8 male) with total of 41 admissions identified. The median PICU stay was 13.5 days (range, 3–24). The most frequent diagnoses were systemic lupus erythematosus (SLE) (48%), followed by systemic vasculitis (16%). Most admissions were from the medical ward (68.3%), while 24.4% from the emergency room. The main reason of PICU admission was a disease flare or related complications (48.8%), followed by infection (34.2%). Fifty one percent of the admissions were due to respiratory dysfunction, 46% required non-invasive respiratory support while 38% was in need for mechanical ventilation. During PICU stay, anti-microbial agents used 90.3%, immunosuppressive treatment adjustment 75.6%, anti-hypertensive 24.4% and vasopressors 12.2%. Twelve patients (48%) fully recovered and 40% partially recovered while three patients died during their PICU stay. The causes of death were macrophage activation syndrome complicated by sepsis in two patients and advanced pulmonary hypertension in one patient.

Conclusion

Our data showed that children with rheumatic diseases, particularly SLE, are mostly admitted to PICU with serious disease exacerbation or severe infection. To improve the outcome, early diagnosis of critical condition and proper intervention are fundamental in reducing mortality.
Teaching More Civil Law at the National University of Singapore: A Necessity for Singapore as a Legal Hub for Asia
Authors: BELL Gary F
Published: July 2019

Singapore aims to be a legal service hub for its region and, therefore, aims to provide legal services to the civil law countries of Southeast and East Asia. One would therefore think that the teaching of at least the rudiments of the civil law (the law of obligations – contracts, delictual liability (tort), quasi-contracts – and property) would be a high priority. However, for all its talk of being ‘Asia's Global Law School’, the NUS Law School does not train its students to handle work from, or in, most of this region. The students are simply not required to learn the very foundations of the civil law tradition. The requirement that they take a course entitled ‘Legal Systems of Asia’ does not ensure that they know the very basics of the civil law. The fact that they must take a course on the law of a civil law country does not ensure that they learn about the civil law. This article suggests how the NUS Law School can make sure that it prepares its students, or at least some of its students, for regional work that includes civil law work.
Weakly nonlinear mode interactions in spherical Rayleigh–Bénard convection
Authors: Mannix P. M. , Mestel A. J.
Published: July 2019

In an annular spherical domain with separation $d$, the onset of convective motion occurs at a critical Rayleigh number $Ra=Ra_{c}$. Solving the axisymmetric linear stability problem shows that degenerate points $(d=d_{c},Ra_{c})$ exist where two modes simultaneously become unstable. Considering the weakly nonlinear evolution of these two modes, it is found that spatial resonances play a crucial role in determining the preferred convection pattern for neighbouring modes $(\ell ,\ell \pm 1)$ and non-neighbouring even modes $(\ell ,\ell \pm 2)$. Deriving coupled amplitude equations relevant to all degeneracies, we outline the possible solutions and the influence of changes in $d,Ra$ and Prandtl number $Pr$. Using direct numerical simulation (DNS) to verify all results, time periodic solutions are also outlined for small $Pr$. The $2:1$ periodic signature observed to be general for oscillations in a spherical annulus is explained using the structure of the equations. The relevance of all solutions presented is determined by computing their stability with respect to non-axisymmetric perturbations at large $Pr$.
Summer surface melt thins Petermann Gletscher Ice Shelf by enhancing channelized basal melt
Authors: WASHAM PETER , NICHOLLS KEITH W. , MÜNCHOW ANDREAS , PADMAN LAURIE
Published: July 2019

Increasing ocean and air temperatures have contributed to the removal of floating ice shelves from several Greenland outlet glaciers; however, the specific contribution of these external forcings remains poorly understood. Here we use atmospheric, oceanographic and glaciological time series data from the ice shelf of Petermann Gletscher, NW Greenland to quantify the forcing of the ocean and atmosphere on the ice shelf at a site ~16 km from the grounding line within a large sub-ice-shelf channel. Basal melt rates here indicate a strong seasonality, rising from a winter mean of 2 m a−1 to a maximum of 80 m a−1 during the summer melt season. This increase in basal melt rates confirms the direct link between summer atmospheric warming around Greenland and enhanced ocean-forced melting of its remaining ice shelves. We attribute this enhanced melting to increased discharge of subglacial runoff into the ocean at the grounding line, which strengthens under-ice currents and drives a greater ocean heat flux toward the ice base.
A novel prognostic biomarker for recurrent aphthous stomatitis: calprotectin
Authors: Kayabasi S , Kuzucu I
Published: July 2019

Objective

This study aims to investigate whether there is a correlation between serum calprotectin concentration and oral ulcer activity in patients with active recurrent aphthous stomatitis.

Method

This prospective, cross-sectional, historical cohort study included 52 patients (26 with active lesions and 26 with inactive lesions) with recurrent aphthous stomatitis and 27 healthy volunteers. The relationship between the groups was statistically evaluated in terms of serum calprotectin level and other inflammatory parameters.

Results

The median calprotectin value of the active lesion group (80.5 ng/ml) was significantly higher than that of the control group (55.4 ng/ml,p= 0.002). Furthermore, the median calprotectin value of the active lesion group was significantly higher than that of the inactive lesion group (72.5 ng/ml,p= 0.017).

Conclusion

In patients with recurrent aphthous stomatitis and active ulcer lesions, the serum calprotectin value can be used as a reliable and robust prognostic marker for inflammation.