bluuebunny/crossref_metadata_2025 huggingface dataset:
Flood regime typology for floodplain ecosystem management as applied to the unregulated Cosumnes River of California, United States
Authors: Whipple Alison A. , Viers Joshua H. , Dahlke Helen E.
Published: December 2016

Floods, with their inherent spatiotemporal variability, drive floodplain physical and ecological processes. This research identifies a flood regime typology and approach for flood regime characterization, using unsupervised cluster analysis of flood events defined by ecologically meaningful metrics, including magnitude, timing, duration, and rate of change as applied to the unregulated lowland alluvial Cosumnes River of California, United States. Flood events, isolated from the 107‐year daily flow record, account for approximately two‐thirds of the annual flow volume. Our analysis suggests six flood types best capture the range of flood event variability. Two types are distinguished primarily by high peak flows, another by later season timing and long duration, two by small magnitudes separated by timing, and the last by later peak flow within the flood event. The flood regime was also evaluated through inter‐ and intra‐annual frequency of the identified flood types, their relationship to water year conditions, and their long‐term trends. This revealed, for example, year‐to‐year variability in flood types, associations between wet years and high peak magnitude types and between dry years and the low magnitude, late season flood type, and increasing and decreasing contribution to total annual flow in the highest two peak magnitude classes, respectively. This research focuses needed attention on floodplains, flood hydrology, ecological implications, and the utility of extending flow regime classification typically used for environmental flow targets. The approach is broadly applicable and extensible to other systems, where findings can be used to understand physical processes, assess change, and improve management strategies.
Dissimilarity in the riparian arthropod communities along surface water permanence gradients in aridland streams
Authors: Moody Eric K. , Sabo John L.
Published: December 2016

The riparian areas around streams and rivers are often thought of as distinct habitats with unique species. Research on riparian zones has traditionally focused on those bordering perennial waterways; thus, we know much less about riparian species supported by intermittent and ephemeral streams. As nonperennial streams make up the vast majority of stream channels in many landscapes, we aimed to investigate how surface water permanence affects riparian communities. We focus on riparian ground‐dwelling arthropods, a group that often depends on resources derived from surface and/or ground water. We sampled riparian ground‐dwelling arthropods along surface water permanence gradients in 3 replicated stream channels in southeastern Arizona to assess patterns in diversity and community similarity. We found that alpha diversity did not differ between reach types, but high species turnover led to significant community dissimilarity among perennial, intermittent, and ephemeral riparian zones. Further, intermittent and ephemeral riparian zones harbored more unique species not found at other reach types than did perennial reaches. These patterns were strongest during the dry season, when intermittent and ephemeral reaches are most likely to lack surface water. Our results suggest not only that the riparian zones of nonperennial streams host equivalent arthropod diversity to their perennial counterparts but also that these communities have little overlap with those at perennial reaches. As a result, intermittent and ephemeral stream channels should receive greater consideration than they currently do in efforts to conserve regional biodiversity.
Pinus contorta invasions increase wildfire fuel loads and may create a positive feedback with fire
Authors: Taylor Kimberley T. , Maxwell Bruce D. , McWethy David B. , Pauchard Aníbal , Nuñez Martín A. , Whitlock Cathy
Published: December 2016

Invasive plant species that have the potential to alter fire regimes have significant impacts on native ecosystems. Concern that pine invasions in the Southern Hemisphere will increase fire activity and severity and subsequently promote further pine invasion prompted us to examine the potential for feedbacks between Pinus contorta invasions and fire in Patagonia and New Zealand. We determined how fuel loads and fire effects were altered by P. contorta invasion. We also examined post‐fire plant communities across invasion gradients at a subset of sites to assess how invasion alters the post‐fire vegetation trajectory. We found that fuel loads and soil heating during simulated fire increase with increasing P. contorta invasion age or density at all sites. However, P. contorta density did not always increase post‐fire. In the largest fire, P. contorta density only increased significantly post‐fire where the pre‐fire P. contorta density was above an invasion threshold. Below this threshold, P. contorta did not dominate after fire and plant communities responded to fire in a similar manner as uninvaded communities. The positive feedback observed at high densities is caused by the accumulation of fuel that in turn results in greater soil heating during fires and high P. contorta density post‐fire. Therefore, a positive feedback may form between P. contorta invasions and fire, but only above an invasion density threshold. These results suggest that management of pine invasions before they reach the invasion density threshold is important for reducing fire risk and preventing a transition to an alternate ecosystem state dominated by pines and novel understory plant communities.
The basis function approach for modeling autocorrelation in ecological data
Authors: Hefley Trevor J. , Broms Kristin M. , Brost Brian M. , Buderman Frances E. , Kay Shannon L. , Scharf Henry R. , Tipton John R. , Williams Perry J. , Hooten Mevin B.
Published: December 2016

Analyzing ecological data often requires modeling the autocorrelation created by spatial and temporal processes. Many seemingly disparate statistical methods used to account for autocorrelation can be expressed as regression models that include basis functions. Basis functions also enable ecologists to modify a wide range of existing ecological models in order to account for autocorrelation, which can improve inference and predictive accuracy. Furthermore, understanding the properties of basis functions is essential for evaluating the fit of spatial or time‐series models, detecting a hidden form of collinearity, and analyzing large data sets. We present important concepts and properties related to basis functions and illustrate several tools and techniques ecologists can use when modeling autocorrelation in ecological data.
Reactivity of a Methoxido–Ruthenium Complex Bearing a Pincer‐Type Bis(carbene) Ligand toward Thiocyanate, Carbon Disulfide, and Isothiocyanate
Authors: Arikawa Yasuhiro , Nakamura Takuo , Higashi Takefumi , Horiuchi Shinnosuke , Sakuda Eri , Umakoshi Keisuke
Published: December 2016

Thiocyanate linkage isomers and two insertion complexes were prepared from a methoxido–ruthenium complex bearing a 2,6‐bis(3‐tert‐butylimidazol‐2‐ylidene)pyridine (CNC) and a bipyridine ligand. In the mixture of the linkage isomers obtained from the substitution reaction, a linear N‐bound and a bent S‐bound isomer were crystallographically determined, and the equilibrium between them at elevated temperature was revealed. On the other hand, in reactions with carbon disulfide (CS2) and phenyl isothiocyanate (PhNCS), the S=C bond was inserted into the Ru–OMe bond, and the resulting ligands are bound to the ruthenium center by the sulfur atom.
AuIII‐Catalyzed Formation of α‐Halomethyl Ketones from Terminal Alkynes
Authors: Xing Yalan , Zhang Ming , Ciccarelli Sarah , Lee John , Catano Bryant
Published: December 2016

A AuIII‐catalyzed synthesis of α‐halomethyl ketones from terminal alkynes was developed. This approach features excellent functional group compatibility and good yields for both aromatic and aliphatic terminal alkynes. The resulting α‐halomethyl ketones were used to prepare heterocyclic indolizine structures. The plausible mechanism of the one‐pot reaction is proposed.
Dopant‐Free Hole‐Transport Material with a Tetraphenylethene Core for Efficient Perovskite Solar Cells
Authors: Zhu Hongwei , Zhang Fei , Liu Xicheng , Sun Mengna , Han Jianlei , You Jing , Wang Shirong , Xiao Yin , Li Xianggao
Published: December 2016

A hole‐transport material (HTM), 1,1,2,2‐tetrakis[4‐(3,6‐di‐tert‐butyl‐9H‐carbazol‐9‐yl)phenyl]ethene (TTBCPE), was prepared straightforwardly and employed in the fabrication of perovskite solar cells (PSCs). The investigated HTM with tetraphenylethene as the core and tert‐butylcarbazole as terminal units was synthesized in two steps from commercially available and cheap raw materials. The devices based on TTBCPE without the use of any dopants and additives exhibited a power conversion efficiency (PCE) of 12.65 %, which is comparable to 14.46 % obtained by using devices based on 2,2′,7,7′‐tetrakis(N,N′‐di‐p‐methoxyphenylamino)‐9,9′‐spirobifluorene (p‐doped spiro‐OMeTAD). Importantly, the device based on TTBCPE showed a higher stability than devices based on doped spiro‐OMeTAD if stored under ambient conditions. In this regard, this easily synthesized and dopant‐free system paves a new way to develop low‐cost HTMs.
Probabilistic development of shear strength model for reinforced concrete squat walls
Authors: Ning Chao‐Lie , Li Bing
Published: December 2016

In order to reconcile the larger scatter and avoid the biased estimate from deterministic predictions for the shear strength of reinforced concrete (RC) squat structural walls, a probabilistic shear strength model is developed in this paper based on the strut‐and‐tie model and the generalized likelihood uncertainty estimation (GLUE) method. The strut‐and‐tie model is used to derive an appropriate function form for the probabilistic shear strength model, where four unknown model parameters (e.g. k1, k2, k3 and k4) are defined carefully to guarantee them having a clear physical‐based meaning so that the corresponding prior distribution ranges can be specified reasonably. Then, the GLUE method is adopted to estimate the posterior cumulative distribution of k1, k2, k3 and k4 with an available experimental database. Furthermore, to demonstrate the stability of the estimated posterior cumulative distribution, the sensitivity of three major aspects in GLUE method is investigated. Finally, based on the estimated cumulative distribution of k1, k2, k3 and k4, the developed probabilistic shear strength model is simplified as a mean prediction model and a standard deviation prediction model for facilitate using in engineering practice. Therefore, with the developed probabilistic shear strength model, not only can the squat structural walls be designed in confidence, but the accuracy of those deterministic predictions can be evaluated in a probabilistic manner. Copyright © 2016 John Wiley & Sons, Ltd.
The mechanisms of nickel toxicity in aquatic environments: An adverse outcome pathway analysis
Authors: Brix Kevin V. , Schlekat Christian E. , Garman Emily R.
Published: December 2016

Current ecological risk assessment and water quality regulations for nickel (Ni) use mechanistically based, predictive tools such as biotic ligand models (BLMs). However, despite many detailed studies, the precise mechanism(s) of Ni toxicity to aquatic organisms remains elusive. This uncertainty in the mechanism(s) of action for Ni has led to concern over the use of tools like the BLM in some regulatory settings. To address this knowledge gap, the authors used an adverse outcome pathway (AOP) analysis, the first AOP for a metal, to identify multiple potential mechanisms of Ni toxicity and their interactions with freshwater aquatic organisms. The analysis considered potential mechanisms of action based on data from a wide range of organisms in aquatic and terrestrial environments on the premise that molecular initiating events for an essential metal would potentially be conserved across taxa. Through this analysis the authors identified 5 potential molecular initiating events by which Ni may exert toxicity on aquatic organisms: disruption of Ca2+ homeostasis, disruption of Mg2+ homeostasis, disruption of Fe2+/3+ homeostasis, reactive oxygen species–induced oxidative damage, and an allergic-type response of respiratory epithelia. At the organ level of biological organization, these 5 potential molecular initiating events collapse into 3 potential pathways: reduced Ca2+ availability to support formation of exoskeleton, shell, and bone for growth; impaired respiration; and cytotoxicity and tumor formation. At the level of the whole organism, the organ-level responses contribute to potential reductions in growth and reproduction and/or alterations in energy metabolism, with several potential feedback loops between each of the pathways. Overall, the present AOP analysis provides a robust framework for future directed studies on the mechanisms of Ni toxicity and for developing AOPs for other metals. Environ Toxicol Chem 2017;36:1128–1137. © 2016 SETAC
Value‐added probiotic development by high‐solid fermentation of sweet potato with Saccharomyces boulardii
Authors: Campbell Carmen , Nanjundaswamy Ananda K. , Njiti Victor , Xia Qun , Chukwuma Franklin
Published: December 2016

Controlled fermentation of Sweet potato (Ipomoea batatas) var. Beauregard by yeast, Saccharomyces boulardii (MAY 796) to enhance the nutritional value of sweet potato was investigated. An average 8.00 × 1010 Colony Forming Units (CFU)/g of viable cells were obtained over 5‐day high‐solid fermentation. Yeast cell viability did not change significantly over time at 4°C whereas the number of viable yeast cells reduced significantly at room temperature (25°C), which was approximately 40% in 12 months. Overall, the controlled fermentation of sweet potato by MAY 796 enhanced protein, crude fiber, neutral detergent fiber, acid detergent fiber, amino acid, and fatty acid levels. Development of value‐added sweet potato has a great potential in animal feed and human nutrition. S. boulardii‐ fermented sweet potato has great potential as probiotic‐enriched animal feed and/or functional food for human nutrition.
Strength varying laws of rock soaked with supercritical CO2drilling fluid and the prediction of safe mud weight window
Authors: Sun Baojiang , Zhang Hongkun
Published: December 2016

Drilling with supercritical CO2(SC‐CO2) is an important new technology in petroleum engineering. The technology has many unique advantages for increasing the penetration rate and reducing formation damage, but it is a disadvantage for the wellbore stability. Therefore, an experimental technique has been developed to determine the safe mud weight window for drilling with SC‐CO2. More specifically, a special experimental apparatus has been designed to mimic thein situtemperature and pressure conditions during drilling operations. Different experiments were conducted using core samples soaked in SC‐CO2and water‐based and oil‐based drilling fluids, respectively. Once the experimental measurements regressed, an empirical correlation, including time, temperature and pressure factors, was obtained to describe the compressive strength of the SC‐CO2‐soaked core samples. Further modifications were then made to the formulations used to calculate the densities of the drilling fluids at the corresponding burst and collapse pressure, respectively. In addition, the effects of dynamic cohesion, internal friction angle, and tensile strength on the wellbore stability were determined. Compared to the conventional water‐based and oil‐based drilling fluids, the SC‐CO2drilling fluid performs better with respect to wellbore stability and has a wider safe mud weight window. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd.
Cortico‐limbic connectivity in MAOA‐L carriers is vulnerable to acute tryptophan depletion
Authors: Eisner Patrick , Klasen Martin , Wolf Dhana , Zerres Klaus , Eggermann Thomas , Eisert Albrecht , Zvyagintsev Mikhail , Sarkheil Pegah , Mathiak Krystyna A. , Zepf Florian , Mathiak Klaus
Published: December 2016

Introduction

A gene–environment interaction between expression genotypes of the monoamine oxidase A (MAOA) and adverse childhood experience increases the risk of antisocial behavior. However, the neural underpinnings of this interaction remain uninvestigated. A cortico‐limbic circuit involving the prefrontal cortex (PFC) and the amygdala is central to the suppression of aggressive impulses and is modulated by serotonin (5‐HT). MAOA genotypes may modulate the vulnerability of this circuit and increase the risk for emotion regulation deficits after specific life events. Acute tryptophan depletion (ATD) challenges 5‐HT regulation and may identify vulnerable neuronal circuits, contributing to the gene–environment interaction.

Methods

Functional magnetic resonance imaging measured the resting‐state state activity in 64 healthy males in a double‐blind, placebo‐controlled study. Cortical maps of amygdala correlation identified the impact of ATD and its interaction with low‐ (MAOA‐L) and high‐expression variants (MAOA‐H) of MAOA on cortico‐limbic connectivity.

Results

Across all Regions of Interest (ROIs) exhibiting an ATD effect on cortico‐limbic connectivity, MAOA‐L carriers were more susceptible to ATD than MAOA‐H carriers. In particular, the MAOA‐L group exhibited a larger reduction of amygdala connectivity with the right prefrontal cortex and a larger increase of amygdala connectivity with the insula and dorsal PCC.

Conclusion

MAOA‐L carriers were more susceptable to a central 5‐HT challenge in cortico‐limbic networks. Such vulnerability of the cortical serotonergic system may contribute to the emergence of antisocial behavior after systemic challenges, observed as gene–environment interaction. Hum Brain Mapp 38:1622–1635, 2017. © 2016 Wiley Periodicals, Inc.
The hippocampus influences assimilation and accommodation of schemata that are not hippocampus‐dependent
Authors: Armelin Anna , Heinemann Uwe , de Hoz Livia
Published: December 2016

Learning is facilitated when information can be incorporated into an already learned set of rules or ‘mental schema’. The location of a new restaurant, for example, is learned more easily if the neighbourhood's general layout is already known. This type of information is processed by the hippocampus and stored as a schema in the cortex, but it is not known whether the hippocampus can also map new stimuli to cortical schemata that are hippocampus‐independent, such as odour classification. Using a hippocampus‐independent odour‐rule task we found that animals without a functional hippocampus learnt which odours did not fit the rule faster than sham animals, which persistently applied the rule to all odours. Conversely, when non‐fitting odours were linked to a new rule sham animals were faster to link these odours to the new rule. The hippocampus, thus, regulates the association of stimuli with existing schemata even when the schemata are hippocampus‐independent. © 2016 Wiley Periodicals, Inc.
The sorting receptor SorCS3 is a stronger regulator of glutamate receptor functions compared to GABAergic mechanisms in the hippocampus
Authors: Christiansen Gitte B. , Andersen Katrine H. , Riis Sarah , Nykjaer Anders , Bolcho Ulrik , Jensen Morten S. , Holm Mai Marie
Published: December 2016

Correct function of glutamate receptors in the postsynaptic density is crucial to synaptic function and plasticity. SorCS3 (sortilin‐related receptor CNS expressed 3) is a sorting receptor which previously has been shown to interact with the key postsynaptic proteins; PSD‐95 and PICK1. In this study, we employed electrophysiological analyses of acute brain slices combined with immunohistochemistry to define the role of SorCS3 in hippocampal synapses in CA1 and the dentate gyrus. We analyzed a juvenile (P17‐21) and a young adult (P55‐65) group of animals from a Sorcs3 knockout mouse model. We show that the basal synaptic transmission is severely affected in SorCS3‐deficient neurons in CA1, while only slightly reduced in the dentate gyrus. Specifically, input/output curves of CA1 synapses revealed a 20% reduction of fEPSP (field excitatory postsynaptic potential) slopes at the highest stimulation intensity in knockouts of the juvenile group, which developed to a 33% decrease in young adult animals. These impairments may be a result of changes in the postsynaptic AMPA receptors. Interestingly, repetitive afferent stimulation demonstrated that SorCS3‐deficient slices respond with an enhanced synaptic facilitation and reduced synaptic depression. These changes also developed with age. A molecular mechanism underlying this relative increase during repetitive stimulations is compatible with enhanced mobility of postsynaptic AMPA receptors resulting in faster exchange of desensitized receptors in the postsynaptic density. The altered response during repetitive stimulation was characteristic for CA1 but not the dentate gyrus. Immunohistochemical analyses of parvalbumin positive neurons combined with paired‐pulse tests of network inhibition and patch‐clamp recordings only showed minute inhibitory changes in SorCS3‐deficient slices. Our results suggest that SorCS3 serves an important role in the postsynaptic protein network, which is more pronounced in CA1 compared to the dentate gyrus. These data support a role for SorCS3 in controlling proper positioning and mobility of glutamate receptors in the postsynaptic density. © 2016 Wiley Periodicals, Inc.
White matter hyperintensities are associated with disproportionate progressive hippocampal atrophy
Authors: Fiford Cassidy M. , Manning Emily N. , Bartlett Jonathan W. , Cash David M. , Malone Ian B. , Ridgway Gerard R. , Lehmann Manja , Leung Kelvin K. , Sudre Carole H. , Ourselin Sebastien , Biessels Geert Jan , Carmichael Owen T. , Fox Nick C. , Cardoso M. Jorge , Barnes Josephine ,   for the Alzheimer's Disease Neuroimaging Initiative
Published: December 2016

This study investigates relationships between white matter hyperintensity (WMH) volume, cerebrospinal fluid (CSF) Alzheimer's disease (AD) pathology markers, and brain and hippocampal volume loss. Subjects included 198 controls, 345 mild cognitive impairment (MCI), and 154 AD subjects with serial volumetric 1.5‐T MRI. CSF Aβ42 and total tau were measured (n = 353). Brain and hippocampal loss were quantified from serial MRI using the boundary shift integral (BSI). Multiple linear regression models assessed the relationships between WMHs and hippocampal and brain atrophy rates. Models were refitted adjusting for (a) concurrent brain/hippocampal atrophy rates and (b) CSF Aβ42 and tau in subjects with CSF data. WMH burden was positively associated with hippocampal atrophy rate in controls (P = 0.002) and MCI subjects (P = 0.03), and with brain atrophy rate in controls (P = 0.03). The associations with hippocampal atrophy rate remained following adjustment for concurrent brain atrophy rate in controls and MCIs, and for CSF biomarkers in controls (P = 0.007). These novel results suggest that vascular damage alongside AD pathology is associated with disproportionately greater hippocampal atrophy in nondemented older adults. © 2016 The Authors Hippocampus Published by Wiley Periodicals, Inc.
Identifying separate impacts of climate and land use/cover change on hydrological processes in upper stream of Heihe River, Northwest China
Authors: Yang Linshan , Feng Qi , Yin Zhenliang , Wen Xiaohu , Si Jianhua , Li Changbin , Deo Ravinesh C.
Published: December 2016

Climate change and land use/cover change (LUCC) are two factors that produce major impacts on hydrological processes. Understanding and quantifying their respective influence is of great importance for water resources management and socioeconomic activities as well as policy and planning for sustainable development. In this study, the Soil and Water Assessment Tool (SWAT) was calibrated and validated in upper stream of the Heihe River in Northwest China. The reliability of the SWAT model was corroborated in terms of the Nash–Sutcliffe efficiency (NSE), the correlation coefficient (R), and the relative bias error (BIAS). The findings proposed a new method employing statistical separation procedures using a physically based modeling system for identifying the individual impacts of climate change and LUCC on hydrology processes, in particular on the aspects of runoff and evapotranspiration (ET).

The results confirmed that SWAT was a powerful and accurate model for diagnosis of a key challenge facing the Heihe River Basin. The model assessment metrics, NSE, R, and BIAS, in the data were 0.91%, 0.95%, and 1.14%, respectively, for the calibration period and 0.90%, 0.96%, and −0.15%, respectively, for the validation period. An assessment of climate change possibility showed that precipitation, runoff, and air temperature exhibited upward trends with a rate of 15.7 mm, 6.1 mm, and 0.38 °C per decade for the 1980 to 2010 period, respectively. Evaluation of LUCC showed that the changes in growth of vegetation, including forestland, grassland, and the shrub area have increased gradually while the barren area has decreased. The integrated effects of LUCC and climate change increased runoff and ET values by 3.2% and 6.6% of the total runoff and ET, respectively. Climate change outweighed the impact of LUCC, thus showing respective increases in runoff and ET of about 107.3% and 81.2% of the total changes. The LUCC influence appeared to be modest by comparison and showed about −7.3% and 18.8% changes relative to the totals, respectively. The increase in runoff caused by climate change factors is more than the offsetting decreases resulting from LUCC. The outcomes of this study show that the climate factors accounted for the notable effects more significantly than LUCC on hydrological processes in the upper stream of the Heihe River.
Second generation slit‐based photoacoustic tomography system for vascular imaging in human
Authors: Wang Yuehang , Wang Depeng , Hubbell Ryan , Xia Jun
Published: December 2016

Slit‐based photoacoustic tomography is a newly developed technique that improves the elevation numerical aperture of a linear array through acoustic diffraction. The slit, placed at the acoustic focus of a linear array, effectively forms an array of virtual detectors with high receiving angle, which subsequently improves the elevation resolution. However, due to the complex implementation, our original system could only image phantoms and sacrificed animals. In this report, the system has been significantly improved. In particular, we designed a slit holder that can be directly mounted to the transducer array for easy adjustment of slit width and simultaneous scanning of both the array and the slit. To enlarge the imaging field of view, we replaced the single circular optical fiber bundle with a bifurcated line fiber bundle which moved simultaneously with the array and the slit. The data acquisition system has also been updated to double the imaging speed. With these improvements, the new system can image a 3.8 × 4 cm2 region within 40 seconds and the object only needs to be coupled through ultrasound gel. We successfully used the system to image vasculatures in the palm and forearm of human volunteers.

3D palm vascular image of human palm.

magnified image

3D palm vascular image of human palm.
Tailoring the physicochemical and shape memory properties of the biodegradable polymer poly(glycerol dodecanoate) via curing conditions
Authors: Solorio Loran D. , Bocks Martin L. , Hollister Scott J.
Published: December 2016

A major challenge in the repair and regeneration of soft tissue damage occurring as a result of aging, injury, or disease is recapitulating the biomechanical properties of the native tissue. Ideally, a candidate biomaterial for soft tissue engineering applications should be biocompatible, nonlinearly elastic to match soft tissue mechanical behavior, biodegradable to enable tissue remodeling, and tailorable to achieve a range of nonlinear elastic mechanical properties to match specific soft tissues. In addition, for cardiac and other applications, the biomaterial should have shape memory characteristics to facilitate minimally invasive and/or catheter‐based delivery. Poly(glycerol dodecanoate) (PGD) is a shape memory material that has nonlinear elastic properties at body temperature and elastic‐plastic behavior at room temperature. In this study, we investigated the effects of curing conditions on the nonlinear elastic, shape memory, and biocompatibility properties of PGD. Increased curing and crosslinking resulted in an increase in both the initial stiffness and the nonlinear strain stiffening behavior of PGD. After shape fixation at 60% strain, 100% shape recovery was achieved within 1 min at body temperature for all conditions tested. Polymer curing had no adverse effects on the cellular biocompatibility or non‐hemolytic characteristics of PGD, indicating the potential suitability of these formulations for blood‐contacting device applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1618–1623, 2017.
Evidence of Staphylococcus Aureus Deformation, Proliferation, and Migration in Canaliculi of Live Cortical Bone in Murine Models of Osteomyelitis
Authors: de Mesy Bentley Karen L , Trombetta Ryan , Nishitani Kohei , Bello-Irizarry Sheila N , Ninomiya Mark , Zhang Longze , Chung Hung Li , McGrath James L , Daiss John L , Awad Hani A , Kates Stephen L , Schwarz Edward M
Published: December 2016

Although Staphylococcus aureus osteomyelitis is considered to be incurable, the major bacterial reservoir in live cortical bone has remained unknown. In addition to biofilm bacteria on necrotic tissue and implants, studies have implicated intracellular infection of osteoblasts and osteocytes as a mechanism of chronic osteomyelitis. Thus, we performed the first systematic transmission electron microscopy (TEM) studies to formally define major reservoirs of S. aureus in chronically infected mouse (Balb/c J) long bone tissue. Although rare, evidence of colonized osteoblasts was found. In contrast, we readily observed S. aureus within canaliculi of live cortical bone, which existed as chains of individual cocci and submicron rod-shaped bacteria leading to biofilm formation in osteocyte lacunae. As these observations do not conform to the expectations of S. aureus as non-motile cocci 1.0 to 1.5 μm in diameter, we also performed immunoelectron microscopy (IEM) following in vivo BrdU labeling to assess the role of bacterial proliferation in canalicular invasion. The results suggest that the deformed bacteria: (1) enter canaliculi via asymmetric binary fission; and (2) migrate toward osteocyte lacunae via proliferation at the leading edge. Additional in vitro studies confirmed S. aureus migration through a 0.5-μm porous membrane. Collectively, these findings define a novel mechanism of bone infection, and provide possible new insight as to why S. aureus implant-related infections of bone tissue are so challenging to treat. © 2016 American Society for Bone and Mineral Research.
Research of bionic design on tools with rostrum of cyrtotrachelus bugueti guer (coleoptera: curculionidae)
Authors: Xu Shun , Li Longhai , Tong Jin , Li Mo
Published: December 2016

To improve the torsional resistance capability of multilayered composite pipes, a bionic design was presented based on the rostrum of Cyrtotrachelus Bugueti Guer. Morphology and mechanical properties of the weevil's rostrum were studied. Scanning electron microscope (SEM) was employed to observe the macro‐/microstructure and inner structure. Nanoindentation was carried out to measure the elastic modulus and the hardness of the biological materials. Based on the structure of rostrum, a mathematical model of multilayered biomimetic pipe was established with the statistical methods. Then, the 3D biomimetic cylinder was built and the torsional resistance capability was analyzed using the finite element analysis. From the SEM and nanoindentation, it was found that the rostrum is a cylindrical hollow multilayered structure composed by three materials. In the transverse section of rostrum, the materials' moduli are 3.07, 3.15, and 8.64 GPa, the hardness are 172.71, 125.32, and 278.99 MPa, respectively. In the longitudinal section, the moduli are 3.01, 4.35, and 7.66 GPa, the hardness are157.46, 149.15, and 253.51 MPa, respectively. The results of simulation showed that the distributional type of lamination has a significant effect on the torsional resistance capability of multilayered structure. The biomimetic structure, which imitates the lamination of rostrum, is superior in the aspect of torsional resistance compared with the nonlaminated or uniform laminated structure. Additionally, the bionic method is feasible and efficient.
High risk of heterosexual transmission of human T‐cell lymphotropic virus type 1 infection in Brazil
Authors: Paiva Arthur , Smid Jerusa , Haziot Michel E.J. , Assone Tatiane , Pinheiro Samara , Fonseca Luiz A.M. , de Oliveira Augusto C.Penalva , Casseb Jorge
Published: December 2016

Human T‐cell lymphotropic virus type 1 is transmitted primarily either through sexual intercourse or from mother to child. The current study investigated sexual transmission and compared the HTLV‐1 proviral load between seroconcordant and serodiscordant couples by examining both men and women among the index partners without using subjective criteria to establish the direction of sexual transmission. Between January 2013 and May 2015, 178 HTLV‐1‐positive patients had spouses, 107 of which had tested partners, thus increasing the initial sample size (46 men and 61 women). Individuals co‐infected with HTLV‐2 or human immunodeficiency virus were not included in the analysis. From among the included participants, 26 men and 26 women were paired with each other, resulting in 26 seroconcordant couples; 12 seroconcordant couples were formed from another four men and eight women. Forty‐three serodiscordant couples were formed from 16 men and 27 women. The rate of seroconcordance was 46.9%. The HTLV‐1 proviral load was compared between 19 and 37 seroconcordant and serodiscondant couples, respectively, and the concordant couples showed higher proviral loads (P = 0.03). There were no differences between the groups according to age, relationship length, having a mother or sibling with HTLV‐1, race, ethnicity, nationality, education, history of blood transfusion, HAM/TSP, ALT, or hepatitis C virus status. In multivariate analysis, relationship time was shown associated with ocurrence of seroconcordance status. The apparent association between high circulating levels of provirus and seroconcordance rate among couples suggests that proviral loads contribute markedly to the risk of sexual transmission, regardless of gender index.
GPNMB ameliorates mutant TDP‐43‐induced motor neuron cell death
Authors: Nagahara Yuki , Shimazawa Masamitsu , Ohuchi Kazuki , Ito Junko , Takahashi Hitoshi , Tsuruma Kazuhiro , Kakita Akiyoshi , Hara Hideaki
Published: December 2016

Glycoprotein nonmetastatic melanoma protein B (GPNMB) aggregates are observed in the spinal cord of amyotrophic lateral sclerosis (ALS) patients, but the detailed localization is still unclear. Mutations of transactive response DNA binding protein 43kDa (TDP‐43) are associated with neurodegenerative diseases including ALS. In this study, we evaluated the localization of GPNMB aggregates in the spinal cord of ALS patients and the effect of GPNMB against mutant TDP‐43 induced motor neuron cell death. GPNMB aggregates were not localized in the glial fibrillary acidic protein (GFAP)‐positive astrocyte and ionized calcium binding adaptor molecule‐1 (Iba1)‐positive microglia. GPNMB aggregates were localized in the microtubule‐associated protein 2 (MAP‐2)‐positive neuron and neurofilament H non‐phosphorylated (SMI‐32)‐positive neuron, and these were co‐localized with TDP‐43 aggregates in the spinal cord of ALS patients. Mock or TDP‐43 (WT, M337V, and A315T) plasmids were transfected into mouse motor neuron cells (NSC34). The expression level of GPNMB was increased by transfection of mutant TDP‐43 plasmids. Recombinant GPNMB ameliorated motor neuron cell death induced by transfection of mutant TDP‐43 plasmids and serum‐free stress. Furthermore, the expression of phosphorylated ERK1/2 and phosphorylated Akt were decreased by this stress, and these expressions were increased by recombinant GPNMB. These results indicate that GPNMB has protective effects against mutant TDP‐43 stress via activating the ERK1/2 and Akt pathways, and GPNMB may be a therapeutic target for TDP‐43 proteinopathy in familial and sporadic ALS. © 2016 Wiley Periodicals, Inc.
Sequential change detection and monitoring of temporal trends in random‐effects meta‐analysis
Authors: Dogo Samson Henry , Clark Allan , Kulinskaya Elena
Published: December 2016

Temporal changes in magnitude of effect sizes reported in many areas of research are a threat to the credibility of the results and conclusions of meta‐analysis. Numerous sequential methods for meta‐analysis have been proposed to detect changes and monitor trends in effect sizes so that meta‐analysis can be updated when necessary and interpreted based on the time it was conducted. The difficulties of sequential meta‐analysis under the random‐effects model are caused by dependencies in increments introduced by the estimation of the heterogeneity parameter τ2. In this paper, we propose the use of a retrospective cumulative sum (CUSUM)‐type test with bootstrap critical values. This method allows retrospective analysis of the past trajectory of cumulative effects in random‐effects meta‐analysis and its visualization on a chart similar to CUSUM chart. Simulation results show that the new method demonstrates good control of Type I error regardless of the number or size of the studies and the amount of heterogeneity. Application of the new method is illustrated on two examples of medical meta‐analyses. © 2016 The Authors. Research Synthesis Methods published by John Wiley & Sons Ltd.
Simultaneous determination of 35 ultra‐trace level organophosphorus pesticide residues in Sanjie Zhentong capsules of traditional Chinese medicine using ultra high performance liquid chromatography with tandem mass spectrometry
Authors: Li Jiachun , Li Dongpo , Wu Jingling , Qin Jianping , Hu Junhua , Huang Wenzhe , Wang Zhenzhong , Xiao Wei , Wang Yu
Published: December 2016

The aim of this study was to develop an analytical method for the simultaneous determination of ultra‐trace levels of 35 organophosphorus pesticide residues in Sanjie Zhentong capsules, a traditional Chinese medicine prescription. A method based on multiclass and multiresidue sample preparation was developed. First, samples were hydrated with water at 4°C. A ratio of 1:3 sample/water was used for each of the sample amounts. Then, different extraction solvents were screened. This step was followed by a dispersive solid‐phase extraction clean‐up procedure using both primary secondary amine and polyamide. A comprehensive sensitive multiresidue liquid chromatography tandem mass spectrometry method was investigated and validated. Good linearity was achieved in the range of 10–500 μg/kg for each analyte. The average recovery ranged from 70 to 120%, except for methamidophos, fonophos, diazinon, and chlorpyriphos‐ethyl, the recoveries of which ranged from 60–70% at the lower concentration level. The precision values were lower than 10% for all the compounds in three concentration levels. The limits of detection and limits of quantification values were 0.01–2.1 and 0.05–3.4 μg/kg, respectively. The matrix effects were determined, and most of the compounds showed signal suppression. Finally, this optimized procedure was applied for the analysis of real samples.
High‐speed counter‐current chromatography assisted preparative isolation of bioactive compounds from stem bark of Juglans mandshurica
Authors: Zhang Yuwei , Lin Hua , Li Shanshan , Chen Jianbo , Sun Yinshi , Li Yuxin
Published: December 2016

High‐speed counter‐current chromatography was applied for the first time for the separation and purification of bioactive compounds contained in the stem bark of Juglans mandshurica Maxim. Silica gel column chromatography was first used to obtain three composition‐enriched target fractions from a crude J. mandshurica methanol extract. Three independent high‐speed counter‐current chromatography processes were then used to further isolate 13 bioactive compounds, namely, six galloyl glucose derivatives, three flavonones, three naphthoquinones, and ethyl gallate. The isolates were identified by ultrahigh‐performance liquid chromatography with tandem mass spectrometry, and ultraviolet and NMR spectroscopy, and compared with literature data. Their purities were determined to be >94.6% by ultrahigh performance liquid chromatography. Furthermore, based on the total phenolic content and results of a 2,2‐diphenyl‐1‐picrylhydrazyl test, the methanol extract and two of the three initial fractions were observed to be rich in phenolic compounds and exhibit good free radical scavenging abilities, while nine of the isolated compounds exhibited remarkable antioxidant activity, superior to that of butyrate hydroxy‐toluene and comparable to that of gallic acid. The results of this research confirm the effectiveness of high‐speed counter‐current chromatography for the separation of compounds contained in extremely complex samples, and provide a basis for the further utilization of J. mandshurica.
The influence of a chronic L‐carnitine administration on the plasma metabolome of male Fischer 344 rats*
Authors: Weinert Christoph H. , Empl Michael T. , Krüger Ralf , Frommherz Lara , Egert Björn , Steinberg Pablo , Kulling Sabine E.
Published: December 2016

Scope

L‐carnitine has been advertised as a fat‐lowering and performance‐enhancing supplement, although scientific evidence for its effectiveness is lacking. The uptake of about 1–2 g of L‐carnitine per day may result in the formation of metabolites like trimethylamine‐N‐oxide (TMAO), which in turn may be converted to potential carcinogens or promote the development of cardiovascular diseases.

Methods and results

To assess whether an L‐carnitine supplementation changes overall metabolism or causes the formation of previously unknown metabolites, we analyzed plasma samples from Fischer 344 rats originating from a previous study using a multi‐platform metabolomics approach comprising LC‐MS/MS and GC×GC‐MS methods. Despite an intake of up to 352 mg L‐carnitine/kg body weight/day for 1 year, plasma concentrations of only 29 out of 359 metabolites were significantly influenced, the induced concentration changes being often comparatively small. Nevertheless, a clear dose‐response relationship and a substantial concentration increase were observed for TMAO, i.e. a tenfold higher TMAO level was measured in the high‐dose group when compared to the control (2.5 versus 25.0 μM).

Conclusion

Although L‐carnitine supplementation did not cause large changes in the plasma metabolome, a higher risk for cardiovascular disease due to chronically elevated TMAO plasma concentrations cannot be excluded.
What explains high life satisfaction in men living with Duchenne muscular dystrophy? A preliminary study to inform psychological intervention
Authors: Graham Christopher D. , Rose Michael R.
Published: December 2016

Introduction

There are increasing numbers of men with Duchenne muscular dystrophy (mDMD). For those who struggle to live with the condition, psychological interventions may be helpful. However, it is unclear how these should be tailored for mDMD. To inform intervention, this study assessed whether 2 well‐validated psychological models (Leventhal's Self‐Regulatory Model; Psychological Flexibility Model) could explain variation in life satisfaction (LS).

Methods

Sixteen mDMD, aged 18–43 years, completed an online survey comprised of questionnaire measures of LS, mood, and both psychological models: Illness Perceptions (Leventhal's Self‐Regulatory Model); engagement in meaningful activity, and acceptance/awareness of difficult thoughts and feelings (Psychological Flexibility Model). A median split enabled comparison of high and low LS groups.

Results

Those with higher LS were characterized by the ability to undertake personally meaningful activity in acceptance of difficult thoughts and feelings.

Conclusions

Results supported the Psychological Flexibility Model. However, methodological limitations mean that these findings should be considered preliminary. Muscle Nerve 56: 163–166, 2017.
Hemodynamic function during finger force production tasks in healthy adults
Authors: Pollonini Luca , Younes Lena , Gorniak Stacey L.
Published: December 2016

Introduction

Near‐infrared spectroscopy (NIRS) is a noninvasive technique used to measure muscle hemodynamics. The focus of this study was to evaluate changes in muscle oxygenation during sustained maximal force production in young, healthy control individuals to establish baseline function in an ideal population.

Methods

NIRS was used to monitor reduced hemoglobin (HbR) and oxygenated hemoglobin (HbO) in forearm muscles. Hemodynamic responses during force production tasks were monitored in real time.

Results

During handgrip exercises, maximal force production declined significantly. Increased HbR was found while HbO remained constant. The correlation between force production and HbO was positive (r = 0.18), while the correlation between force and HbR was negative (r = ‐0.48). The application of NIRS to monitor the correlation between force production and hemodynamic measures in the forearm was successful. These data set the foundation for future use of NIRS as a diagnostic tool for individuals with peripheral vascular disease: Muscle Nerve 56: 472–478, 2017
Neurite growth could be impaired by ETFDH mutation but restored by mitochondrial cofactors
Authors: Liang Wen‐Chen , Lin Yen‐Fong , Liu Ting‐Yuan , Chang Shin‐Cheng , Chen Bai‐Hsiun , Nishino Ichizo , Jong Yuh‐Jyh
Published: December 2016

Introduction

c.250G>A (p.Ala84Thr) in ETFDH is the most common mutation that causes later‐onset multiple acyl‐coenzyme A dehydrogenase deficiency (MADD) in the southern Chinese population. No functional study has targeted this mutation.

Methods

Using cells expressing ETFDH‐wild‐type (WT) or ETFDH‐mutant (p.Ala84Thr), reactive oxygen species (ROS) production and neurite length were analyzed, followed by pathomechanism exploration and drug screening.

Results

Increased ROS production and marked neurite shortening were observed in the cells expressing the ETFDH‐mutant, compared with WT. Further studies demonstrated that suberic acid, an accumulated intermediate metabolite in MADD, could significantly impair neurite outgrowth of NSC34 cells, but neurite shortening could be restored by supplementation with carnitine, riboflavin, or Coenzyme Q10.

Conclusions

Neurite shortening caused by the c.250G>A mutation in ETFDH suggests that neural defects could be underdiagnosed in human patients with MADD. This impairment might be treatable with mitochondrial cofactor supplementation. Muscle Nerve 56: 479–485, 2017