bluuebunny/crossref_metadata_2025 huggingface dataset:
Does Sexual Selection Influence Ornamentation of Hemipenes in Old World Snakes?
Authors: Andonov Kostadin , Natchev Nikolay , Kornilev Yurii V. , Tzankov Nikolay
Published: June 2017

In the present study, we investigated and documented the morphology of the male copulatory organs (hemipenes) in fifteen wide‐ranging snake species. The species represent four families (Boidae, Colubridae, Lamprophiidae, and Viperidae) and ten genera. We applied the same preparation techniques for all species, successfully everting and expanding the organs completely. The detailed description of the general morphology of the male copulatory organs was based on 31 specimens. Our data were compared with published observations and we point out some incorrectly described details in previous investigations. We provide the first description of the hemipenial morphology for three ophidian species (Elaphe sauromates, Telescopus fallax, and Malpolon insignitus). In addition to the morphological characteristics of the hemipenes presented in the research, we propose the adoption of a standardized index describing the hemipenial proportions. The immense variation in hemipenial morphology presupposes its dynamic evolution, but we suggest that many of the significant structures observed here may have escaped previous researchers due to differing methodologies. Some of the highly ornamented morphologies that we describe are consistent with a locking mechanism during copulation. However, other morphologies may relate to the variety of mating behaviors observed. As a result, we propose that sexual selection is the major driver affecting the hemipenial ornamentation in snakes. Anat Rec, 300:1680–1694, 2017. © 2017 Wiley Periodicals, Inc.
Increased CCL25 and T Helper Cells Expressing CCR9 in the Salivary Glands of Patients With Primary Sjögren's Syndrome: Potential New Axis in Lymphoid Neogenesis
Authors: Blokland Sofie L. M. , Hillen Maarten R. , Kruize Aike A. , Meller Stephan , Homey Bernhard , Smithson Glennda M. , Radstake Timothy R. D. J. , van Roon Joel A. G.
Published: June 2017

Objective

Follicular helper T (Tfh) cells play a critical role in germinal center formation and B cell activation, both of which are hallmarks of primary Sjögren's syndrome (SS). CCR9‐expressing T helper cells have “Tfh‐like” characteristics and their numbers are increased at mucosa‐associated sites in several inflammatory conditions. Because the characteristics of these cells are unique and evaluation has been limited, this study was undertaken to investigate the local and systemic CCL25/CCR9 axis in patients with primary SS.

Methods

Levels of CCL25 protein and messenger RNA (mRNA) and CCR9+ T helper cells were evaluated in the labial salivary glands (LSGs) of patients with primary SS and patients with sicca syndrome without a diagnosis of primary SS (non‐SS sicca controls). CCL25 levels were assessed for correlation with parameters of inflammation and clinical features. Circulating CCR9+ and CXCR5+ T helper cells were compared on the basis of phenotypic and functional properties.

Results

CCL25 protein and mRNA levels were elevated in the LSGs of patients with primary SS as compared to non‐SS sicca controls. Increased levels of CCL25 were associated with B cell hyperactivity, autoimmunity, and levels of interleukin‐21 (IL‐21) and soluble IL‐7 receptor α‐chain (IL‐7Rα). Furthermore, the frequency of CCR9‐expressing cells in the LSGs was increased and levels of circulating CCR9+ T helper cells expressing programmed death 1 and inducible T cell costimulator were elevated in patients with primary SS. CCR9+ T helper cells displayed higher expression of IL‐7Rα and secreted higher levels of interferon‐γ, IL‐17, IL‐4, and IL‐21 as compared to CXCR5+ T helper cells, ex vivo and upon triggering with antigen or IL‐7. Both CCR9+ and CXCR5+ T helper cells induced IgG production by B cells more potently than that induced in the cultures with CCR9−CXCR5− T helper cells.

Conclusion

Enhanced expression of CCL25 in LSGs of patients with primary SS can facilitate attraction of CCR9+ T helper cells, and these cells secrete high levels of proinflammatory cytokines when triggered with antigen or IL‐7. The observed associations with B cell hyperactivity, autoimmunity, and markers of lymphoid neogenesis indicate that the CCL25/CCR9 axis plays a significant role in the immunopathology of primary SS, suggesting that this axis could represent a novel therapeutic target for the disease.
Chloroplasten liefern Abwehrproteine an den Zellkern
Authors: Krupinska Karin
Published: June 2017

Aktuelle Forschungen haben am Beispiel der Infektion von Tabakpflanzen mit dem Tabakmosaikvirus (TMV) gezeigt, dass auch Proteine aus den Chloroplasten an der Abwehr von Pathogenen beteiligt sind [1]. Als Stromuli bezeichnete Fortsätze spielen als Transportwege für das Protein aus den Chloroplasten in den Zellkern möglicherweise eine entscheidende Rolle.
A flexible e‐learning resource promoting the critical reading of scientific papers for science undergraduates
Authors: Letchford Julie , Corradi Hazel , Day Trevor
Published: June 2017

An important aim of undergraduate science education is to develop student skills in reading and evaluating research papers. We have designed, developed, and implemented an on‐line interactive resource entitled “Evaluating Scientific Research literature” (ESRL) aimed at students from the first 2 years of the undergraduate program. In this article, we describe the resource, then use student data collected from questionnaire surveys to evaluate the resource within 2 years of its launch. Our results add to those reported previously and indicate that ESRL can enable students to start evaluating research articles when used during their undergraduate program. We conclude maximal learning is likely to occur when the resource can be embedded in the curriculum such that students have a clearly articulated context for the resource's activities, can see their relevance in relation to assessed assignments and can be encouraged to think deeply about the activities in conversation with one another and/or with staff. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(6):483–490, 2017.
CHEMOTION: A gesture based chemistry virtual laboratory with leap motion
Authors: Al‐Khalifa Hend S.
Published: June 2017

Chemistry laboratories are expensive to setup and operate as well as it entails safety issues. However, as technologies develop and new technologies are being produced every day, an advance solution for physical Chemistry laboratories limitation is the use of virtual laboratories. In this paper, we present the design and implementation of a virtual chemistry laboratory system that utilizes gesture computing technology to create an interactive and entertaining laboratory application for pupils. The system is software that works on PCs with the help of Leap motion controller, off‐the‐shelf gesture recognition hardware, to simulate a chemistry laboratory. The system provides number of experiments to perform along with tutorials and quizzes. A preliminary usability evaluation of the system shows the high level of interest from the pupils in using such a system and the positive feedback.
Glycodendrimers as Chondroitin Sulfate Mimetics: Synthesis and Binding to Growth Factor Midkine
Authors: Domínguez‐Rodríguez Pedro , Reina José J. , Gil‐Caballero Sergio , Nieto Pedro M. , de Paz José L. , Rojo Javier
Published: June 2017

Chondroitin sulfate (CS) is a member of the glycosaminoglycan (GAG) family, a class of polysaccharides implicated in relevant biological functions. The structural complexity of these carbohydrates demands the development of simple glycomimetics as useful tools to study the biological processes in which GAGs are involved. In this work we described the synthesis of the disaccharide unit of the CS‐E (GlcA‐GalNAc(4,6‐di‐OSO3)), in a multivalent presentation. Using a fluorescence polarization competition assay we have demonstrated that a hexavalent dendrimer of this disaccharide interact with midkine, in the low micromolar range. This result highlights the potency of these disaccharide‐displaying multivalent systems as interesting mimetics of longer and synthetically more complex GAG oligosaccharides.
Synthesis and Antigenic Evaluation of Oligosaccharide Mimics of Vi Antigen from Salmonella typhi
Authors: Zhang Gao‐Lan , Yang Lin , Zhu Jingjing , Wei Mengman , Yan Wanjun , Xiong De‐Cai , Ye Xin‐Shan
Published: June 2017

Salmonella typhi is responsible for typhoid fever, which is a serious health threat in developing countries. As a virulent factor of Salmonella typhi, the purified Vi polysaccharide (Vi PS) has become an effective vaccine to combat typhoid fever. The chemical synthesis can provide homogeneous and well‐defined molecules for the development of Vi‐based vaccines. However, the synthesis of Vi oligosaccharides in high yields and with exclusive α‐stereoselectivities remains very challenging. In this paper, a series of Vi pseudooligosaccharides, including pseudo tetra‐, hexa‐, and octa‐saccharides were efficiently synthesized. These oligosaccharide analogues were conjugated by carbon chain tether through olefin cross metathesis or by the 1,2,3‐triazole moiety through copper (I)‐catalyzed alkyne–azide cycloaddition reaction (CuAAC). The binding affinities of these oligosaccharide mimics to anti‐Vi antibodies were investigated. These results will be beneficial to the further development of Vi‐based oligosaccharide vaccines.
Multiagent induction chemotherapy followed by chemoradiation is associated with improved survival in locally advanced pancreatic cancer
Authors: Torgeson Anna , Lloyd Shane , Boothe Dustin , Tao Randa , Whisenant Jonathan , Garrido‐Laguna Ignacio , Cannon George M.
Published: June 2017

BACKGROUND

The role of chemoradiotherapy (CRT) in locally advanced pancreatic cancer (LAPC) is uncertain after multiple randomized clinical trials have yielded mixed results. The authors used the National Cancer Data Base (NCDB) to determine whether CRT yields a survival benefit compared with chemotherapy alone (CT).

METHODS

Patients with nonmetastatic LAPC diagnosed during 2004 through 2014 were identified in the NCDB. Patients who received CT were compared with those who received CRT using chi‐square analysis. Univariate and multivariate Cox regression analyses were used to compare demographic, clinical, and treatment characteristics that were predictive of survival. Propensity score matching and shared frailty analysis were done. Subgroup analyses were undertaken to examine patients who underwent pancreatectomy and cohorts of patients who received different CT or CRT regimens.

RESULTS

In total, 8689 patients with LAPC were identified. CRT was associated with improved survival (median survival [MS], 13.5 months) compared with CT (MS, 10.6 months) on multivariate analysis (hazard ratio [HR], 0.80; P < .001). Induction chemotherapy before CRT (HR, 0.67; P < .001) and multiagent chemotherapy (HR, 0.72; P < .001) were also identified as independent predictors of survival compared with concurrent CRT and single‐agent CT, respectively. Patients in the CRT group who received multiagent induction chemotherapy had superior MS and pancreatectomy rates (MS, 17.5 months; HR, 0.70; P < .001; pancreatectomy rate, 10%) compared with those who received multiagent CT alone (MS, 12.4 months; pancreatectomy rate, 3.3%). Patients who underwent pancreatectomy experienced improved survival (MS, 22 vs 10.6 months; HR, 0.39; P < .001).

CONCLUSIONS

In this NCDB analysis, maximizing systemic chemotherapy before CRT improved survival compared with CT alone in patients with LAPC. Continued analysis of CRT in properly selected patients after maximized systemic therapy is needed. Cancer 2017;123:3816‐24. © 2017 American Cancer Society.
Sustainable Separations of C4‐Hydrocarbons by Using Microporous Materials
Authors: Gehre Mascha , Guo Zhiyong , Rothenberg Gadi , Tanase Stefania
Published: June 2017

Petrochemical refineries must separate hydrocarbon mixtures on a large scale for the production of fuels and chemicals. Typically, these hydrocarbons are separated by distillation, which is extremely energy intensive. This high energy cost can be mitigated by developing materials that can enable efficient adsorptive separation. In this critical review, the principles of adsorptive separation are outlined, and then the case for C4 separations by using zeolites and metal–organic frameworks (MOFs) is examined. By analyzing both experimental and theoretical studies, the challenges and opportunities in C4 separation are outlined, with a focus on the separation mechanisms and structure–selectivity correlations. Zeolites are commonly used as adsorbents and, in some cases, can separate C4 mixtures well. The pore sizes of eight‐membered‐ring zeolites, for example, are in the order of the kinetic diameters of C4 isomers. Although zeolites have the advantage of a rigid and highly stable structure, this is often difficult to functionalize. MOFs are attractive candidates for hydrocarbon separation because their pores can be tailored to optimize the adsorbate–adsorbent interactions. MOF‐5 and ZIF‐7 show promising results in separating all C4 isomers, but breakthrough experiments under industrial conditions are needed to confirm these results. Moreover, the flexibility of the MOF structures could hamper their application under industrial conditions. Adsorptive separation is a promising viable alternative and it is likely to play an increasingly important role in tomorrow's refineries.
How can distinct egg polymorphism be maintained in the rufescent prinia (Prinia rufescens)–plaintive cuckoo (Cacomantis merulinus) interaction—a modeling approach
Authors: Liang Wei , Yang Canchao , Takasu Fugo
Published: June 2017

In avian brood parasitism, both the host and the parasite are expected to develop various conflicting adaptations; hosts develop a defense against parasitism, such as an ability to recognize and reject parasitic eggs that look unlike their own, while parasites evolve egg mimicry to counter this host defense. Hosts may further evolve to generate various egg phenotypes that are not mimicked by parasites. Difference in egg phenotype critically affects the successful reproduction of hosts and parasites. Recent studies have shown that clear polymorphism in egg phenotype is observed in several host–parasite interactions, which suggests that egg polymorphism may be a more universal phenomenon than previously thought. We examined the mechanism for maintaining egg polymorphism in the rufescent prinia (Prinia rufescens) that is parasitized by the plaintive cuckoo (Cacomantis merulinus) from a theoretical viewpoint based on a mathematical model. The prinia has four distinct egg phenotypes: immaculate white, immaculate blue, white with spots, and blue with spots. Only two egg phenotypes, white with spots and blue with spots, are found in the cuckoo population. We show that the observed prinia and cuckoo phenotypes cannot be at an equilibrium and that egg polymorphism can be maintained either at stationary equilibrium or with dynamic, frequency oscillations, depending on the mutation rates of the background color and spottiness. Long‐term monitoring of the prinia–cuckoo interaction over a wide geographic range is needed to test the results of the model analyses.
The role of macroinvertebrates for conservation of freshwater systems
Authors: Nieto Carolina , Ovando Ximena M.C. , Loyola Rafael , Izquierdo Andrea , Romero Fátima , Molineri Carlos , Rodríguez José , Rueda Martín Paola , Fernández Hugo , Manzo Verónica , Miranda María José
Published: June 2017

Freshwater ecosystems are the most threatened ecosystems worldwide. Argentinian‐protected areas have been established mainly to protect vertebrates and plants in terrestrial ecosystems. In order to create a comprehensive biodiverse conservation plan, it is crucial to integrate both aquatic and terrestrial systems and to include macroinvertebrates. Here, we address this topic by proposing priority areas of conservation including invertebrates, aquatic ecosystems, and their connectivity and land uses. Location: Northwest of Argentina. We modeled the ecological niches of different taxa of macroinvertebrates such as Coleoptera, Ephemeroptera, Hemiptera, Megaloptera, Lepidoptera, Odonata, Plecoptera, Trichoptera, Acari, and Mollusca. Based on these models, we analyzed the contribution of currently established protected areas in the conservation of the aquatic biodiversity and we propose a spatial prioritization taking into account possible conflict regarding different land uses. Our analysis units were the real watersheds, to which were added longitudinal connectivity up and down the rivers. A total of 132 species were modeled in the priority area analyses. The analysis 1 showed that only an insignificant percentage of the macroinvertebrates distribution is within the protected areas in the North West of Argentina. The analyses 2 and 3 recovered similar values of protection for the macroinvertebrate species. The upper part of Bermejo, Salí‐Dulce, San Francisco, and the Upper part of Juramento basins were identified as priority areas of conservation. The aquatic ecosystems need special protection and 10% or even as much as 17% of land conservation is insufficient for species of macroinvertebrates. In turn the protected areas need to combine the aquatic and terrestrial systems and need to include macroinvertebrates as a key group to sustain the biodiversity. In many cases, the land uses are in conflict with the conservation of biodiversity; however, it is possible to apply the connectivity of the watersheds and create multiple‐use modules.
Characterization of measurement errors using structure‐from‐motion and photogrammetry to measure marine habitat structural complexity
Authors: Bryson Mitch , Ferrari Renata , Figueira Will , Pizarro Oscar , Madin Josh , Williams Stefan , Byrne Maria
Published: June 2017

Habitat structural complexity is one of the most important factors in determining the makeup of biological communities. Recent advances in structure‐from‐motion and photogrammetry have resulted in a proliferation of 3D digital representations of habitats from which structural complexity can be measured. Little attention has been paid to quantifying the measurement errors associated with these techniques, including the variability of results under different surveying and environmental conditions. Such errors have the potential to confound studies that compare habitat complexity over space and time. This study evaluated the accuracy, precision, and bias in measurements of marine habitat structural complexity derived from structure‐from‐motion and photogrammetric measurements using repeated surveys of artificial reefs (with known structure) as well as natural coral reefs. We quantified measurement errors as a function of survey image coverage, actual surface rugosity, and the morphological community composition of the habitat‐forming organisms (reef corals). Our results indicated that measurements could be biased by up to 7.5% of the total observed ranges of structural complexity based on the environmental conditions present during any particular survey. Positive relationships were found between measurement errors and actual complexity, and the strength of these relationships was increased when coral morphology and abundance were also used as predictors. The numerous advantages of structure‐from‐motion and photogrammetry techniques for quantifying and investigating marine habitats will mean that they are likely to replace traditional measurement techniques (e.g., chain‐and‐tape). To this end, our results have important implications for data collection and the interpretation of measurements when examining changes in habitat complexity using structure‐from‐motion and photogrammetry.
Discrepancies in occupancy and abundance approaches to identifying and protecting habitat for an at‐risk species
Authors: Dibner Reilly R. , Doak Daniel F. , Murphy Melanie
Published: June 2017

Predicting how environmental factors affect the distribution of species is a fundamental goal of conservation biology. Conservation biologists rely on species distribution and abundance models to identify key habitat characteristics for species. Occupancy modeling is frequently promoted as a practical alternative to use of abundance in identifying habitat quality. While occupancy and abundance are potentially governed by different limiting factors operating at different scales, few studies have directly compared predictive models for these approaches in the same system. We evaluated how much occupancy and abundance are driven by the same environmental factors for a species of conservation concern, the greater short‐horned lizard (Phrynosoma hernandesi). Occupancy was most strongly dictated by precipitation, temperature, and density of ant mounds. While these factors were also in the best‐supported predictive models for lizard abundance, the magnitude of the effects varied, with the sign of the effect changing for temperature and precipitation. These discrepancies show that while occupancy modeling can be an efficient approach for conservation planning, predictors of occupancy probability should not automatically be equated with predictors of population abundance. Understanding the differences in factors that control occupancy versus abundance can help us to identify habitat requirements and mitigate the loss of threatened species.
High salmon density and low discharge create periodic hypoxia in coastal rivers
Authors: Sergeant Christopher J. , Bellmore J. Ryan , McConnell Casey , Moore Jonathan W.
Published: June 2017

Dissolved oxygen (DO) is essential to the survival of almost all aquatic organisms. Here, we examine the possibility that abundant Pacific salmon (Oncorhynchus spp.) and low streamflow combine to create hypoxic events in coastal rivers. Using high‐frequency DO time series from two similar watersheds in southeastern Alaska, we summarize DO regimes and the frequency of hypoxia in relationship to salmon density and stream discharge. We also employ a simulation model that links salmon oxygen respiration to DO dynamics and predicts combinations of salmon abundance, discharge, and water temperature that may result in hypoxia. In the Indian River, where DO was monitored hourly during the ice‐free season from 2010 to 2015, DO levels decreased when salmon were present. In 2013, a year with extremely high spawning salmon densities, DO dropped to 1.7 mg/L and 16% saturation, well below lethal limits. In Sawmill Creek, where DO was monitored every six minutes across an upstream–downstream gradient during the 2015 spawning season, DO remained fully saturated upstream of spawning reaches, but declined markedly downstream to 2.9 mg/L and 26% saturation during spawning. Modeled DO dynamics in the Indian River closely tracked field observations. Model sensitivity analysis illustrates that low summertime river discharge is a precursor to salmon‐induced oxygen depletion in our study systems. Our results provide compelling evidence that dense salmon populations and low discharge can trigger hypoxia, even in rivers with relatively cold thermal regimes. Although climate change modeling for southeastern Alaska predicts an increase in annual precipitation, snowfall in the winter and rainfall in the summer are likely to decrease, which would in turn decrease summertime discharge in rain‐ and snow‐fed streams and potentially increase the frequency of hypoxia. Our model template can be adapted by resource managers and watershed stakeholders to create real‐time predictive models of DO trends for individual streams. While preserving thermally suitable stream habitat for cold‐water taxa facing climate change has become a land management priority, managers should also consider that some protected watersheds may still be at risk of increasingly frequent hypoxia due to human impacts such as water diversion and artificially abundant salmon populations caused by hatchery straying.
Sequential Nucleophilic C(sp3)‐Benzylation/C(sp2)–H Arylation for the Synthesis of Spiro[oxindole‐3,5′‐pyrrolo[2,1‐a]isoquinolines]
Authors: Zhang Tinglei , Cui Baodong , Han Wenyong , Wan Nanwei , Bai Mei , Chen Yongzheng
Published: June 2017

An efficient strategy for the synthesis of spirocyclic indolizidine derivatives that have a 3,3′‐disubstituted oxindole framework has been described. By using sequential nucleophilic C(sp3)‐benzylation and palladium‐catalyzed C(sp2)–H arylation reactions of 3‐pyrrolyloxindoles and 2‐(bromomethyl)aryl bromides, a series of spiro[oxindole‐3,5′‐pyrrolo[2,1‐a]isoquinolines] were smoothly obtained in up to 92 % yield. A synthetic application of this method was also demonstrated by the transformation of 3u into functionalized compound 4. Moreover, the catalytic cycle of this cascade reaction was proposed on the basis of results of control experiments.
Review of emerging metabolomic tools and resources: 2015–2016
Authors: Misra Biswapriya B. , Fahrmann Johannes F. , Grapov Dmitry
Published: June 2017

Data processing and analysis are major bottlenecks in high‐throughput metabolomic experiments. Recent advancements in data acquisition platforms are driving trends toward increasing data size (e.g., petabyte scale) and complexity (multiple omic platforms). Improvements in data analysis software and in silico methods are similarly required to effectively utilize these advancements and link the acquired data with biological interpretations. Herein, we provide an overview of recently developed and freely available metabolomic tools, algorithms, databases, and data analysis frameworks. This overview of popular tools for MS and NMR‐based metabolomics is organized into the following sections: data processing, annotation, analysis, and visualization. The following overview of newly developed tools helps to better inform researchers to support the emergence of metabolomics as an integral tool for the study of biochemistry, systems biology, environmental analysis, health, and personalized medicine.
Influence of heat pre‐treated inoculum and pH control on the hydrogen production by microbial consortium
Authors: Braz Romão Betânia , Moreira Silva Felipe Thalles , Coutinho de Barcelos Costa Henrique , Santos Moreira Felipe , de Souza Ferreira Juliana , Regina Xavier Batista Fabiana , Luiz Cardoso Vicelma
Published: June 2017

The production of hydrogen by biological route can be affected by various parameters. This work evaluated the influence of pH control during the fermentation process and the application of different inoculum heat pre‐treatment in the production of biohydrogen using cheese whey permeate as a substrate. The tested pH values were 5.5 and 6.5, and the thermal pre‐treatment was 50° C for 15 days and 93°C for 15 min. Results indicated that when the fermentation was controlled at pH 5.5 responses productivity and yield were, 129.33 (mmol H2/day L) and 4.04 (mol H2/mol substrate consumed), respectively. These results were higher compared with those obtained in the fermentation without pH control and pH controlled at 6.5. Regarding to the most efficient treatment was the thermal shock of 93°C for 15 min, maintaining the fermentation temperature at 30°C. Under this condition, the synthesis of hydrogen was faster and the maximum production was achieved in 25 h of process (128.82 mmol H2/day L), while the maximum production of the assay using non‐treated inoculum was attained in 43 h (109.14 mmol H2/day L). © 2017 American Institute of Chemical Engineers Environ Prog, 37: 505–512, 2018
Comparison of forecasting performances: Does normalization and variance stabilization method beat GARCH(1,1)‐type models? Empirical evidence from the stock markets
Authors: Gulay Emrah , Emec Hamdi
Published: June 2017

In this paper, we present a comparison between the forecasting performances of the normalization and variance stabilization method (NoVaS) and the GARCH(1,1), EGARCH(1,1) and GJR‐GARCH(1,1) models. Hence the aim of this study is to compare the out‐of‐sample forecasting performances of the models used throughout the study and to show that the NoVaS method is better than GARCH(1,1)‐type models in the context of out‐of sample forecasting performance. We study the out‐of‐sample forecasting performances of GARCH(1,1)‐type models and NoVaS method based on generalized error distribution, unlike normal and Student's t‐distribution. Also, what makes the study different is the use of the return series, calculated logarithmically and arithmetically in terms of forecasting performance. For comparing the out‐of‐sample forecasting performances, we focused on different datasets, such as S&P 500, logarithmic and arithmetic BİST 100 return series. The key result of our analysis is that the NoVaS method performs better out‐of‐sample forecasting performance than GARCH(1,1)‐type models. The result can offer useful guidance in model building for out‐of‐sample forecasting purposes, aimed at improving forecasting accuracy.
Evaluation of Drip Fertigation Uniformity Affected by Injector Type, Pressure Difference and Lateral Layout
Authors: Fan Junliang , Wu Lifeng , Zhang Fucang , Yan Shicheng , Xiang Youzhen
Published: June 2017

The effects of three injector types (differential pressure tank, Venturi injector and water‐driven piston proportional pump), three pressure differences (0.10, 0.15 and 0.20 MPa) and two lateral layouts (longitudinal and transversal) on drip fertigation uniformity were comprehensively evaluated through field experiments. No statistically significant differences in water uniformity were found between injector types or pressure differences, while the influence of lateral layouts on water uniformity was significant (α = 0.05). All affecting factors showed an extremely significant influence on fertilizer uniformity (α = 0.01). Water uniformity was better than fertilizer uniformity, both of which generally decreased with increasing pressure differences. The differential pressure tank produced a lower water and fertilizer uniformity than the Venturi injector and proportional pump. The longitudinal lateral layout produced lower fertigation uniformity than the transversal lateral layout. To ensure both high water and fertilizer uniformity in fertigation systems, a Venturi injector and a proportional pump with relatively constant fertilizer concentration are recommended. When a differential pressure tank is used, the differential pressure should be minimized to mitigate the decrease in fertilizer concentration. The differential pressure tank can give high fertigation uniformity (≥ 90%) comparable to the Venturi injector and proportional pump if the transversal lateral layout is further applied. The research provides scientific guidance for the design and operational management of drip fertigation systems in greenhouse vegetables or field crops. Copyright © 2017 John Wiley & Sons, Ltd.
Black and White Parents’ Willingness to Seek Help for Children's Internalizing and Externalizing Symptoms
Authors: Thurston Idia B. , Hardin Robin , Decker Kristina , Arnold Trisha , Howell Kathryn H. , Phares Vicky
Published: June 2017

Objective

Understanding social and environmental factors that contribute to parental help‐seeking intentions is an important step in addressing service underutilization for children in need of treatment. This study examined factors that contribute to parents’ intentions to seek formal and informal help for child psychopathology (anxiety and attention‐deficit/hyperactivity disorder [ADHD]).

Method

A total of 251 parents (N = 128 mothers, N = 123 fathers; 49% Black, 51% White) read 3 vignettes describing children with anxiety, ADHD, and no diagnosis. Measures of problem recognition, perceived barriers, and formal (pediatricians, psychologists, teachers) and informal (religious leaders, family/friends, self‐help) help seeking were completed. Four separate hierarchical logistic regression models were used to examine parental help‐seeking likelihood from formal and informal sources for internalizing and externalizing symptoms. Predictors were socioeconomic status, parent race, age, and sex, parent problem recognition (via study vignettes), and perceived barriers to mental health service utilization.

Result

Mothers were more likely than fathers to seek help from pediatricians, psychologists, teachers, and religious leaders for child anxiety and pediatricians, religious leaders, and self‐help resources for child ADHD. Black parents were more likely to seek help from religious leaders and White parents were more likely to use self‐help resources. Problem recognition was associated with greater intentions to seek help from almost all formal and informal sources (except from friends/family).

Conclusion

Understanding factors that contribute to parental help seeking for child psychopathology is critical for increasing service utilization and reducing the negative effects of mental health problems. This study highlights the importance of decreasing help‐seeking barriers and increasing problem recognition to improve health equity.
What did the “Unossified zone” of the non‐mammalian therapsid braincase house?
Authors: Laaß Michael , Schillinger Burkhard , Kaestner Anders
Published: June 2017

Most nonmammalian synapsids possess a mid‐dorsal depression in the brain cavity known as the “unossified zone.” It remains obscure which structures this zone contained, and, as candidates, the vermis of the cerebellum, the superior sagittal sinus, a junction of several blood vessels, the pineal gland or other midbrain structures were considered. Neutron tomography of a skull of Diictodon feliceps (Therapsida, Anomodontia) revealed some clear impressions of canals in this region of the brain cavity. Furthermore, the prootic sinus probably ran on the internal surface of the pila antotica and had a similar course in anomodonts as it has been proposed for cynodonts and Mesozoic mammals. Comparisons with the vascular systems of nonmammalian synapsids and mammals suggest that the unossified zone is best interpreted as a terminal chamber of the anterior segment of the medial head vein, which housed the junction of the superior sagittal sinus and the transverse sinuses. Consequently, the system of cranial vessels in Diictodon reveals a partial division of the medial head vein system into an anterior and a posterior segment at an early stage of synapsid evolution, which is consistent with the well‐known common pattern of early ontogenetic development in amniotes. J. Morphol., 2017. © 2017 Wiley Periodicals, Inc.
Reduction of acrylamide content in bread crust by starch coating
Authors: Liu Jie , Liu Xiaojie , Man Yong , Liu Yawei
Published: June 2017

BACKGROUND

A technique of starch coating to reduce acrylamide content in bread crust was proposed. Bread was prepared in accordance with a conventional procedure and corn or potato starch coating was brushed on the surface of the fermented dough prior to baking.

RESULTS

Corn starch coating caused a decrease in acrylamide of 66.7% and 77.1% for the outer and inner crust, respectively. The decrease caused by the potato starch coating was 68.4% and 77.4%, respectively. Starch coating reduced asparagine content significantly (43.4–82.9%; P < 0.01)in both the outer and inner crust. A lower temperature (difference of 10–20 °C) in combination with a higher moisture content (maximum difference of 8%) of bread crust were a result of starch coating, which effectively shortened the time span (4–8 min) over which acrylamide could form and accumulate.

CONCLUSION

The present study demonstrates that starch coating could be a simple, effective and practical application for reducing acrylamide levels in bread crust without changing the texture and crust color of bread. © 2017 Society of Chemical Industry
Technical Note: Comparison of megavoltage, dual‐energy, and single‐energy CT‐based μ‐maps for a four‐channel breast coil in PET/MRI
Authors: Patrick John C. , Terry Thompson R. , So Aaron , Butler John , Faul David , Stodilka Robert Z. , Yartsev Slav , Prato Frank S. , Gaede Stewart
Published: June 2017

Purpose

The purpose of this study was to describe and evaluate methods for calculating a megavoltage computed tomography (MVCT)‐derived MR hardware attenuation map (μ‐map) and dual‐energy CT (DECT) for 511 keV photons.

Methods

Phantom measurements were acquired on a whole‐body hybrid PET/MRI system, using a four‐channel receive‐only MR radiofrequency (RF) breast coil. Two acquisitions were performed: with the phantoms positioned in the four‐channel RF breast coil, and without the breast coil. PET attenuation from the breast coil was corrected using three different CT‐derived hardware μ‐maps: (a) Single‐energy CT (SECT), (b) DECT, and (c) MVCT. Each attenuation‐corrected (AC) PET volume was evaluated and compared with the acquisition performed without the breast coil.

Results

The breast coil attenuated PET photons by 10% overall. Threshold values were applied to the SECT μ‐map to reduce the effects of metal artifacts, but overcorrection occurred in more highly attenuated regions. The DECT‐derived virtual monochromatic image reduced beam‐hardening artifacts, but other metal artifacts remained. Despite the remaining metal artifacts in the DECT image, it led to an improvement in the more attenuated regions. The MVCT images appear to be free from metal artifacts leading to an artifact‐free μ‐map and a further improvement AC‐PET images.

Conclusions

Our MVCT‐based approach for creating μ‐maps for MR RF coils greatly reduces artifacts produced by metal in a SECT approach. This eliminates the need for other artifact reduction methods, including the application of a threshold of narrow beam attenuation coefficients, or disassembling hardware to remove high‐Z components before imaging with a kilovoltage source.
Efficient solution algorithms for multiaxial probabilistic elasto‐plastic constitutive simulations of soils
Authors: Sadrinezhad Arezoo , Sett Kallol , Hariharan S. I.
Published: June 2017

A Fokker‐Planck‐Kolmogorov (FPK) equation approach has recently been developed to probabilistically solve any elastic‐plastic constitutive equation with uncertain material parameters by transforming the nonlinear, stochastic constitutive rate equation into a linear, deterministic partial differential equation (PDE) and thereby simplifying the numerical solution process. For an uniaxial problem, conventional numerical techniques, such as the finite difference or finite element methods, may be used to solve the resulting univariate FPK PDE. However, for a multiaxial problem, an efficient algorithm is necessary for tractability of the numerical solution of the multivariate FPK PDE. In this paper, computationally efficient algorithms, based on a Fourier spectral approach, are presented for solving FPK PDEs in (stress) space and (pseudo) time, having space‐independent but time‐dependent coefficients and both space‐ and time‐dependent coefficients, that commonly arise in probabilistic elasto‐plasticity. The algorithms are illustrated by probabilistically simulating 2 common laboratory constitutive experiments in geotechnical engineering, namely, the unconfined compression test and the unconsolidated undrained triaxial compression test.
Pregabalin and heart failure: A population‐based study
Authors: Ho Joanne M.‐W. , Macdonald Erin M. , Luo Jin , Gomes Tara , Antoniou Tony , Mamdani Muhammad M. , Juurlink David N.
Published: June 2017

Purpose

The anticonvulsant pregabalin is increasingly prescribed for pain, seizures, and psychiatric disorders. Although evidence suggests pregabalin can cause edema and heart failure, its cardiac safety profile in clinical practice is unknown. We sought to examine the risk of heart failure among older patients receiving pregabalin compared to those receiving gabapentin.

Methods

We conducted a population‐based cohort study of Ontarians aged 66 and older with a history of seizure who received pregabalin or gabapentin between April 2013 and March 2014. We used propensity scores to match patients commencing pregabalin to those commencing gabapentin. The primary outcome was an emergency department visit or hospitalization for heart failure within 90 days.

Results

We studied 9855 patients who initiated pregabalin and an equal number treated with gabapentin. In the primary analysis, we found no difference in the risk of heart failure with pregabalin compared to gabapentin (1.2% versus 1.3%, hazard ratio of 0.77; 95% CI 0.58‐1.03). Secondary analyses stratified for baseline history of heart failure yielded similar findings.

Conclusion

In a large cohort of older patients with a seizure disorder, pregabalin was not associated with an increased risk of heart failure relative to gabapentin.
Comprehensive study on the relationships between the processing, the microstructure, and mechanical properties of injection molded polypropylenes
Authors: Barbosa Carlos N. , Simoes Ricardo , Franzen Markus , Baranowski Thomas , Viana Julio C.
Published: June 2017

The relationship between the morphologies of different injection molded polypropylenes and their tensile properties measured at high strain rate were investigated. A threefold systematic analysis is proposed by establishing the following relationships: (i) processing‐morphology; (ii) processing‐mechanical properties; and (iii) morphology‐mechanical properties. Experimental techniques were used to assess the structural heterogeneity of the moldings, namely: polarized light microscopy (skin thickness), wide‐angle X‐ray scattering (crystallinity, molecular orientation, and polymorphism of the skin layer), and differential scanning calorimetry (bulk crystallinity). High velocity tensile tests (1 m/s) were recorded by a high speed camera that runs 20k frames per second. The influence of multiple processing variables on the morphology and properties was studied adopting a structured statistical approach by means of two statistical tools: analysis of variance and response surface methodology. The most important molding variables and their interactions were identified. Straightforward relationships between the morphology and the tensile properties were established by fitting the experimental data to polynomial equations, using a least‐square minimization procedure. The melt temperature was identified as the most significant variable for the development of the morphologies and the mechanical response of the moldings. The skin thickness, its crystallinity and molecular orientation (flow direction) influence, to a certain degree, the tensile properties of the materials. POLYM. ENG. SCI., 58:E215–E225, 2018. © 2017 Society of Plastics Engineers
High‐Yield Synthesis of Au@Ag Right Bipyramids and Self‐Assembly into Four‐Leaf‐Clover‐like Structures
Authors: Ji Fei , Zhong Qixuan , Chen Jianmei , Chen Lei , Hu Huicheng , Liu Qipeng , Yang Peipei , Yu Jiaqi , Jiang Lin , Xu Yong , Gross Elad , Zhang Qiao
Published: June 2017

Bimetallic core–shell nanostructures are of great interest because of their unique properties. Although bimetallic core–shell nanostructures with plenty of shapes are prepared, synthesis of core–shell nanostructures with asymmetric core and shells is still elusive. This work reports a facile seed‐mediated synthesis of Au@Ag right bipyramids with high yield (>95%) and broadly tunable edge length (from ≈130 to ≈230 nm) as well as tunable localized surface plasmon resonance properties. For the first time, a four‐leaf‐clover‐like tetramer of bipyramids is obtained through self‐assembly of the synthesized Au@Ag right bipyramids. The as‐assembled structure performs well in surface‐enhanced Raman spectroscopy with an analytical enhancement factor up to 1.4 × 107 because of the existence of both sharp tips and “hot‐spots.” The present work not only develops a new kind of nanomaterials, but also shows promising applications in optics and sensing.
Spontaneous delamination via compressive buckling facilitates large‐scale β‐Ga2O3 thin film transfer from reusable GaAs substrates
Authors: Kaya Ahmet , Dryden Daniel M. , Woodall Jerry M. , Islam M. Saif
Published: June 2017

The fabrication and transfer via spontaneous delamination of large‐area, high‐quality β‐Ga2O3 nanoscale thin films with centimeter‐scale dimensions is demonstrated via thermal oxidation of reusable GaAs substrates. The films are characterized by using X‐ray diffraction, energy dispersive spectroscopy, Raman spectroscopy, and scanning electron microscopy. The film demonstrates good mechanical flexibility facilitating reliable transfer. The β‐Ga2O3 film's optical band gap and Schottky barrier height with gold are 4.8 and 1.03 eV, respectively. Electrical and optical properties of the transferable β‐Ga2O3 thin films exhibit a potential for application in solar‐blind photodetectors. The scale of the β‐Ga2O3 films transferred herein exceeds what the research community has reported to‐date by more than four orders of magnitude. The macroscopic dimensions of the transferred films may offer a remedy for the low thermal conductance of β‐Ga2O3 via transfer onto substrates with high thermal conductivity.
Geometry‐induced quantum effects in periodic nanostructures
Authors: Tavkhelidze A. , Jangidze L. , Mebonia M. , Piotrowski K. , Więckowski J. , Taliashvili Z. , Skhiladze G. , Nadaraia L.
Published: June 2017

Recently, geometry‐induced quantum effects in periodic nanostructures were introduced and observed. Nanograting has been shown to dramatically improve thermoelectric and electron emission properties, and originate a geometry induced doping or G‐doping. Here, we concentrate on experimental investigation of G‐doping. We fabricate nanograting (NG) layers and measure their electron transport properties. The grating was fabricated on the surface of a silicon on insulator (SOI) wafer device layer using laser interference lithography followed by reactive ion etching. Next, large square islands were shaped in the device layer. The characteristics of NG and plain islands were compared to investigate G‐doping. Resistivity temperature dependences were recorded in the range of 4–300 K. For all 21 samples, the NG layers show a 2–3 order of magnitude reduction in resistivity with respect to the plain layer. Hall coefficient and thermopower measurements demonstrate that the NG layers are n‐type. Obtained G‐doping level corresponded to an “effective impurity” concentration of 1018 cm−3. The dependence of the resistivity and Hall coefficient on temperature and magnetic field were recorded in the ranges of 2–300 K and 0–3 T, respectively.
Synthesis and characterization of a cellulose‐based molecularly imprinted polymer in aqueous solution: The study of Furosemide slow release
Authors: Fareghi Amir Reza , Moghadam Peyman Najafi , Khalafy Jabbar
Published: June 2017

In the present study, a green and biodegradable molecularly imprinted polymer (MIP) based on cellulose is introduced for Furosemide drug for the first time. Firstly sodium carboxymethyl cellulose (CMC) was synthesized from microcrystalline cellulose. Then the prepared CMC underwent cross‐linking in the drug pre‐assembly solution using 2‐hydroxyethyl methacrylate as the comonomer and ammonium peroxydisulfate as the CMC activating agent. The pre‐assembly solution of the drug was also prepared using Furosemide as the template molecule and acrylamide as the functional monomer in aqueous medium. The obtained results from binding and selectivity studies indicated the successful preparation of the CMC‐based MIP (CMC‐MIP) in aqueous solution. Besides, structural, thermal, and morphological characterization of the prepared system was investigated. In the final step, the in vitro release study of Furosemide from the synthesized polymers was carried out in pH = 7.41 phosphate buffered saline solution at 37°C. According to the results, the CMC‐MIP had a larger drug loading capacity and a higher amount of drug release at its equilibrium state compared to the corresponding non‐imprinted polymer (CMC‐NIP). Moreover, the drug release profiles showed that the drug release rate of the CMC‐MIP is more controlled than that of the CMC‐NIP, especially at the early stages of release.