bluuebunny/crossref_metadata_2025 huggingface dataset:
Linking river flow regimes to riparian plant guilds: a community‐wide modeling approach
Authors: Lytle David A. , Merritt David M. , Tonkin Jonathan D. , Olden Julian D. , Reynolds Lindsay V.
Published: March 2017

Modeling riparian plant dynamics along rivers is complicated by the fact that plants have different edaphic and hydrologic requirements at different life stages. With intensifying human demands for water and continued human alteration of rivers, there is a growing need for predicting responses of vegetation to flow alteration, including responses related to climate change and river flow management. We developed a coupled structured population model that combines stage‐specific responses of plant guilds with specific attributes of river hydrologic regime. The model uses information on the vital rates of guilds as they relate to different hydrologic conditions (flood, drought, and baseflow), but deliberately omits biotic interactions from the structure (interaction neutral). Our intent was to (1) consolidate key vital rates concerning plant population dynamics and to incorporate these data into a quantitative framework, (2) determine whether complex plant stand dynamics, including biotic interactions, can be predicted from basic vital rates and river hydrology, and (3) project how altered flow regimes might affect riparian communities. We illustrated the approach using five flow‐response guilds that encompass much of the river floodplain community: hydroriparian tree, xeroriparian shrub, hydroriparian shrub, mesoriparian meadow, and desert shrub. We also developed novel network‐based tools for predicting community‐wide effects of climate‐driven shifts and deliberately altered flow regimes. The model recovered known patterns of hydroriparian tree vs. xeroriparian shrub dominance, including the relative proportion of these two guilds as a function of river flow modification. By simulating flow alteration scenarios ranging from increased drought to shifts in flood timing, the model predicted that mature hydroriparian forest should be most abundant near the observed natural flow regime. Multiguild sensitivity analysis identified substantial network connectivity (many connected nodes) and biotic linkage (strong pairwise connections between nodes) under natural flow regime conditions. Both connectivity and linkage were substantially reduced under drought and other flow‐alteration scenarios, suggesting that community structure is destabilized under such conditions. This structured population modeling approach provides a useful tool for understanding the community‐wide effects of altered flow regimes due to climate change and management actions that influence river flow regime.
Integrating ecological theories and traits in process‐based modeling of macroinvertebrate community dynamics in streams
Authors: Mondy Cédric P. , Schuwirth Nele
Published: March 2017

Predicting the composition and dynamics of communities is a challenging but useful task to efficiently support ecosystem management. Community ecology has developed a number of promising theories, including food webs, metabolic theory, ecological stoichiometry, and environmental filtering. Their joint implementation in a mechanistic modeling framework should help us to bring community ecology to a new level by improving its predictive abilities. One of the challenges lies in the proper consideration of model uncertainty. In this paper, we contribute to this challenging task by modeling the temporal dynamics of macroinvertebrate communities in a stream subjected to hydropeaking in Switzerland. To this end, we extended the mechanistic model Streambugs regarding flood‐induced drift processes and the use of trait information to define performance filters. Model predictions without any calibration were in the right order of magnitude but did not reflect the dynamics of most of the invertebrate taxa well. Bayesian inference drastically improved the model fit. It revealed that a large share of total model output uncertainty can be attributed to observation errors, which exceeded model parameter uncertainty. Observed and simulated community‐aggregated traits helped to identify and understand model deficits. The combination of different ecological theories and trait information in a single mechanistic modeling framework combined with Bayesian inference can thus help to predict responses of communities to environmental changes, which can support ecosystem management.
Aggregative and feeding thresholds of sympatric rorqual whales within a fjord system
Authors: Keen Eric M.
Published: March 2017

Rorqual whales (f. Balaenopteridae) supposedly respond to increases in prey supply according to both aggregative and feeding thresholds. With the former, they gather in areas above a minimum prey density set by their basal metabolic needs. With the latter, feeding occurs only above a prey density set by the energetic cost of lunge feeding. To compare prey preferences and the two threshold types in sympatric rorquals, I conducted systematic transect surveys and behavioral observations of humpback whales (Megaptera novaeangliae) and fin whales (Balaenoptera physalus) in a British Columbia fjord system. While multiple prey features were found to influence whale aggregation and feeding, both threshold types were observed in each species' response to krill volume. Humpback response to prey features was less predictable and influenced by more factors than that of fin whales, which appeared to be exclusively euphausivorous and interested in the deepest high‐volume krill patches within the deepest channels. Compared with fin whales, humpbacks found higher‐volume krill patches and had higher aggregative thresholds, but had lower feeding thresholds. Findings aligned overall with the expectations that aggregative behavior is responsive to local prey supply, while feeding thresholds are governed by less mutable energetic constraints imposed by body size and feeding mode. Both aggregative and feeding threshold responses appeared to be a function of local conditions: As total krill‐like backscatter increased, feeding thresholds stabilized (became more nonlinear and more nonrandom), while aggregative thresholds destabilized. All results emphasized the importance of incorporating observations of feeding effort in studies of prey preference and habitat use.
Shrub encroachment in Arctic tundra: Betula nana effects on above‐ and belowground litter decomposition
Authors: McLaren Jennie R. , Buckeridge Kate M. , van de Weg Martine J. , Shaver Gaius R. , Schimel Joshua P. , Gough Laura
Published: March 2017

Rapid arctic vegetation change as a result of global warming includes an increase in the cover and biomass of deciduous shrubs. Increases in shrub abundance will result in a proportional increase of shrub litter in the litter community, potentially affecting carbon turnover rates in arctic ecosystems. We investigated the effects of leaf and root litter of a deciduous shrub, Betula nana, on decomposition, by examining species‐specific decomposition patterns, as well as effects of Betula litter on the decomposition of other species. We conducted a 2‐yr decomposition experiment in moist acidic tundra in northern Alaska, where we decomposed three tundra species (Vaccinium vitis‐idaea, Rhododendron palustre, and Eriophorum vaginatum) alone and in combination with Betula litter. Decomposition patterns for leaf and root litter were determined using three different measures of decomposition (mass loss, respiration, extracellular enzyme activity). We report faster decomposition of Betula leaf litter compared to other species, with support for species differences coming from all three measures of decomposition. Mixing effects were less consistent among the measures, with negative mixing effects shown only for mass loss. In contrast, there were few species differences or mixing effects for root decomposition. Overall, we attribute longer‐term litter mass loss patterns to patterns created by early decomposition processes in the first winter. We note numerous differences for species patterns between leaf and root decomposition, indicating that conclusions from leaf litter experiments should not be extrapolated to below‐ground decomposition. The high decomposition rates of Betula leaf litter aboveground, and relatively similar decomposition rates of multiple species below, suggest a potential for increases in turnover in the fast‐decomposing carbon pool of leaves and fine roots as the dominance of deciduous shrubs in the Arctic increases, but this outcome may be tempered by negative litter mixing effects during the early stages of encroachment.
Body mass index and distribution of body fat can influence sensory detection and pain sensitivity
Authors: Tashani O. A , Astita R. , Sharp D. , Johnson M. I
Published: March 2017

Background

The aim of this study was to investigate the influence of body fat percentage and its distribution on sensory detection and pain sensitivity responses to experimentally induced noxious stimuli in otherwise pain‐free individuals.

Methods

Seventy‐two participants were divided into three equal groups according to their body mass index (BMI: normal, overweight and obese). Percentage body fat was estimated using a four‐site skinfold method. Measurements of cold pressor pain threshold, tolerance and intensity; contact thermal sensory detection and heat pain threshold and tolerance (TSA‐II – NeuroSensory Analyzer, Medoc); and blunt pressure pain threshold (algometer, Somedic SenseLab AB) were taken at the waist and thenar eminence.

Results

Mean ± SD pressure pain threshold of the obese group (620.72 ± 423.81 kPa) was significantly lower than normal (1154.70 ± 847.18 kPa) and overweight (1285.14 ± 998.89 kPa) groups. Repeated measures ANOVA found significant effects for site for cold detection threshold (F1,68 = 8.3, p = 0.005) and warm detection threshold (F1,68 = 38.69, p = 0.001) with waist having lower sensory detection thresholds than thenar eminence. For heat pain threshold, there were significant effects for site (F1,68 = 4.868, p = 0.031) which was lower for waist compared with thenar eminence (mean difference = 0.89 °C).

Conclusion

Obese individuals were more sensitive than non‐obese individuals to pressure pain but not to thermal pain. Body sites may vary in their response to different types and intensities of stimuli. The inconsistency of findings within and between research studies should catalyse further research in this field.

Significance

This study provided evidence that body mass index and distribution of body fat can influence sensory detection and pain sensitivity. Obese individuals were more sensitive than normal range body mass index individuals to pressure pain but not to thermal pain. Pain response varied according to subcutaneous body fat at different body sites. These findings strengthen arguments that weight loss should be a significant aspect of a pain management programme for obese pain patients.
Using affinity capillary electrophoresis and computational models for binding studies of heparinoids with p‐selectin and other proteins
Authors: Mozafari Mona , Balasupramaniam Shantheya , Preu Lutz , El Deeb Sami , Reiter Christian G. , Wätzig Hermann
Published: March 2017

A fast and precise affinity capillary electrophoresis (ACE) method has been developed and applied for the investigation of the binding interactions between P‐selectin and heparinoids as potential P‐selectin inhibitors in the presence and absence of calcium ions. Furthermore, model proteins and vitronectin were used to appraise the binding behavior of P‐selectin. The normalized mobility ratios (∆R/Rf), which provided information about the binding strength and the overall charge of the protein–ligand complex, were used to evaluate the binding affinities. It was found that P‐selectin interacts more strongly with heparinoids in the presence of calcium ions. P‐selectin was affected by heparinoids at the concentration of 3 mg/L. In addition, the results of the ACE experiments showed that among other investigated proteins, albumins and vitronectin exhibited strong interactions with heparinoids. Especially with P‐selectin and vitronectin, the interaction may additionally induce conformational changes. Subsequently, computational models were applied to interpret the ACE experiments. Docking experiments explained that the binding of heparinoids on P‐selectin is promoted by calcium ions. These docking models proved to be particularly well suited to investigate the interaction of charged compounds, and are therefore complementary to ACE experiments.
Exploration of defatted waste feed stock for the continuous production of biomethane under psychrophilic outdoor conditions
Authors: Singhal Shailey , Sharma Rajan , Agarwal Shilpi , Arora Shefali , Singhal Naveen
Published: March 2017

The present work focuses on the bio‐methane production potential of jatropha defatted waste (JDFW) in batch type continuous stirred tank reactor (CSTR). JDFW was codigested with cow dung (CD) as inoculum in various ratios. 75:25 ratio of JDFW and CD with carbon to nitrogen (C/N) ratio 12:1 was chosen as the optimum to run in CSTR. 65–69% methane was obtained in 0.184m3 of biogas per kg of total solid in only 15 days. The efficient energy gain and reduction in hydraulic retention time (HRT) of bio‐methane production process was successfully accomplished by minimizing the usage of fresh water and external nutrients. The integration of anaerobic digestion with CSTR could maintain the sustainability of biomethane production, and also significantly reduced the HRT of the process. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 845–849, 2017
Decreased functional connectivity within a language subnetwork in benign epilepsy with centrotemporal spikes
Authors: McGinnity Colm J. , Smith Anna B. , Yaakub Siti N. , Weidenbach Gerbase Sofia , Gammerman Anya , Tyson Adam L. , Bell Tiffany K. , Elmasri Marwa , Barker Gareth J. , Richardson Mark P. , Pal Deb K.
Published: March 2017

Objective

Benign epilepsy with centrotemporal spikes (BECTS, also known as Rolandic epilepsy) is a common epilepsy syndrome that is associated with literacy and language impairments. The neural mechanisms of the syndrome are not known. The primary objective of this study was to test the hypothesis that functional connectivity within the language network is decreased in children with BECTS. We also tested the hypothesis that siblings of children with BECTS have similar abnormalities.

Methods

Echo planar magnetic resonance (MR) imaging data were acquired from 25 children with BECTS, 12 siblings, and 20 healthy controls, at rest. After preprocessing with particular attention to intrascan motion, the mean signal was extracted from each of 90 regions of interest. Sparse, undirected graphs were constructed from adjacency matrices consisting of Spearman's rank correlation coefficients. Global and nodal graph metrics and subnetwork and pairwise connectivity were compared between groups.

Results

There were no significant differences in graph metrics between groups. Children with BECTS had decreased functional connectivity relative to controls within a four‐node subnetwork, which consisted of the left inferior frontal gyrus, the left superior frontal gyrus, the left supramarginal gyrus, and the right inferior parietal lobe (p = 0.04). A similar but nonsignificant decrease was also observed for the siblings. The BECTS groups had significant increases in connectivity within a five‐node, five‐edge frontal subnetwork.

Significance

The results provide further evidence of decreased functional connectivity between key mediators of speech processing, language, and reading in children with BECTS. We hypothesize that these decreases reflect delayed lateralization of the language network and contribute to specific cognitive impairments.
Understanding mass fluvial erosion along a bank profile: using PEEP technology for quantifying retreat lengths and identifying event timing
Authors: Papanicolaou A. N. Thanos , Wilson Christopher G. , Tsakiris Achilles G. , Sutarto Tommy E. , Bertrand Fabienne , Rinaldi Massimo , Dey Subhasish , Langendoen Eddy
Published: March 2017

This study provides fundamental examination of mass fluvial erosion along a stream bank by identifying event timing, quantifying retreat lengths, and providing ranges of incipient shear stress for hydraulically driven erosion. Mass fluvial erosion is defined here as the detachment of thin soil layers or conglomerates from the bank face under higher hydraulic shear stresses relative to surface fluvial erosion, or the entrainment of individual grains or aggregates under lower hydraulic shear stresses.

We explore the relationship between the two regimes in a representative, US Midwestern stream with semi‐cohesive bank soils, namely Clear Creek, IA. Photo‐Electronic Erosion Pins (PEEPs) provide, for the first time, in situ measurements of mass fluvial erosion retreat lengths during a season. The PEEPs were installed at identical locations where surface fluvial erosion measurements exist for identifying the transition point between the two regimes. This transition is postulated to occur when the applied shear stress surpasses a second threshold, namely the critical shear stress for mass fluvial erosion.

We hypothesize that the regimes are intricately related and surface fluvial erosion can facilitate mass fluvial erosion. Selective entrainment of unbound/exposed, mostly silt‐sized particles at low shear stresses over sand‐sized sediment can armor the bank surface, limiting the removal of the underlying soil. The armoring here is enhanced by cementation from the presence of optimal levels of sand and clay. Select studies show that fluvial erosion strength can increase several‐fold when appropriate amounts of sand and clay are mixed and cement together. Hence, soil layers or conglomerates are entrained with higher flows.

The critical shear stress for mass fluvial erosion was found to be an order of magnitude higher than that of surface fluvial erosion, and proceeded with higher (approximately 2–4 times) erodibility. The results were well represented by a mechanistic detachment model that captures the two regimes. Copyright © 2017 John Wiley & Sons, Ltd.
New cooperative mechanisms for software defined networks based on hybrid switches
Authors: Alvarez‐Horcajo Joaquin , Martinez‐Yelmo Isaias , Rojas Elisa , Carral Juan A. , Lopez‐Pajares Diego
Published: March 2017

Software defined networking (SDN) aims to provide simplified network design, operation, and management using a decoupled control plane. However, its centralized control and global network knowledge present scalability and reliability issues, which makes SDN deployment very challenging. In this paper, we propose and evaluate a hybrid switch with partial delegation of basic bridging and new cooperative mechanisms between controller and switches. This delegation offloads the SDN controllers while maintaining the capability to install forwarding rules on the switches. In this way, we take full advantage of hybrid switches in addition to using them as backwards compatible equipment, which interoperates with traditional switches.We validate this proposal by implementing a hybrid OpenFlow switch on an open source software switch as a proof of concept. Scalability and path setup delay are improved with respect to traditional centralized SDN solutions, because of the reduction in controller load and, in turn, because of the reduced traffic between switches and controller. Our cooperative mechanisms focus on recovering failures, obtaining the best performance of all approaches on higher loads, and providing a good trade‐off between controller based and traditional distributed approaches.
Uplink resource allocation in multiuser multicarrier cognitive radio networks under power amplifier nonlinearity
Authors: Baghani Mina , Mohammadi Abbas , Majidi Mahdi , Valkama Mikko
Published: March 2017

In this paper, the nonlinear distortion effects of power amplifiers are studied, in particular from uplink subcarrier and power allocation perspectives in multiuser multicarrier cognitive networks. The out‐of‐band emissions of a nonlinear power amplifier create interference to the other users. The target is then to maximize the achievable uplink rate in a multiuser multicarrier cognitive network where a cognitive user should not introduce interference to the other users more than a specified threshold level, called interference power constraint. This task is formulated as a convex optimization problem with interference power constraints. Obtaining a closed‐form solution for this problem is, however, not feasible due to its nonlinear nature. Accordingly, the problem is solved numerically, and extensive simulations are conducted to obtain performance results. The obtained results are also compared with a more simple heuristic approach. The results show that the proposed scheme provides a maximum rate while at the same time also guaranteeing that the interference levels are lower than the specified interference power constraint. The results also indicate that the maximum rate can be closely approximated by using the assisted or optimization‐directed heuristic approach.
AHNS series: Do you know your guidelines? Management of head and neck cancer in the era of human papillomavirus: Educating our patients on human papillomavirus
Authors: Guo Theresa , Goldenberg David , Fakhry Carole
Published: March 2017

Human papillomavirus (HPV) has changed the face of head and neck cancer over the past 2 decades. No longer is this solely a disease of older patients with a history of heavy tobacco and alcohol use. Patients with HPV‐related head and neck cancers tend to be younger, healthier, and have an improved prognosis, compared with those with HPV‐negative tumors. As more patients are diagnosed with HPV‐related head and neck cancer, physicians have important topics to consider. These include prevalence, transmission, and natural history of HPV, the role of screening, vaccines, and HPV testing in head and neck cancer. This article continues a series developed by the American Head and Neck Society's Education Committee entitled “Do you know your guidelines?” and is intended to provide guidance for navigating common questions and concerns patients may have about HPV infection and HPV‐related head and neck cancer. © 2017 Wiley Periodicals, Inc. Head Neck 39: 833–839, 2017
Transcription factor EGR1 promotes differentiation of bovine skeletal muscle satellite cells by regulating MyoG gene expression
Authors: Zhang WeiWei , Tong HuiLi , Zhang ZiHeng , Shao ShuLi , Liu Dan , Li ShuFeng , Yan YunQin
Published: March 2017

The transcription factor, early growth response 1 (EGR1), has important roles in various cell types in response to different stimuli. EGR1 is thought to be involved in differentiation of bovine skeletal muscle‐derived satellite cells (MDSCs); however, the precise effects of EGR1 on differentiation of MDSCs and its mechanism of action remain unknown. In the present study, a time course of EGR1 expression and the effects of EGR1 on MDSC differentiation were determined. The results demonstrated that the expression of EGR1 mRNA and protein increased significantly in differentiating MDSCs relative to that in proliferating cells. Over‐expression of the EGR1 gene in MDSCs promoted their differentiation and inhibited proliferation. Conversely, knock‐down of EGR1 inhibited differentiation of MDSCs and promoted their proliferation, indicating that EGR1 promotes MDSC differentiation. Moreover, over‐expression of EGR1 in MDSCs increased the expression of MyoG mRNA and protein, whereas its knock‐down had the opposite effect. Furthermore, ChIP‐PCR analyses demonstrated that EGR1 could bind directly to its putative binding site within the promoter region of MyoG, and determination of ERG1 subcellular localization in MDSCs demonstrated that it could relocate to the nucleus, indicating MyoG is likely an EGR1 target gene whose expression is positively regulated by this transcription factor. In conclusion, EGR1 can promote MDSC differentiation through positive regulation of MyoG gene expression.
Nuclear phosphoinositide regulation of chromatin
Authors: Hamann Bree L. , Blind Raymond D.
Published: March 2017

Phospholipid signaling has clear connections to a wide array of cellular processes, particularly in gene expression and in controlling the chromatin biology of cells. However, most of the work elucidating how phospholipid signaling pathways contribute to cellular physiology have studied cytoplasmic membranes, while relatively little attention has been paid to the role of phospholipid signaling in the nucleus. Recent work from several labs has shown that nuclear phospholipid signaling can have important roles that are specific to this cellular compartment. This review focuses on the nuclear phospholipid functions and the activities of phospholipid signaling enzymes that regulate metazoan chromatin and gene expression. In particular, we highlight the roles that nuclear phosphoinositides play in several nuclear‐driven physiological processes, such as differentiation, proliferation, and gene expression. Taken together, the recent discovery of several specifically nuclear phospholipid functions could have dramatic impact on our understanding of the fundamental mechanisms that enable tight control of cellular physiology.
Successful ultrasound‐guided percutaneous embolization of renal pseudoaneurysm by autologous blood clot: Preliminary report of a new method
Authors: Zare Mehrjardi Mohammad , Bagheri Seyed Morteza , Darabi Mohsen
Published: March 2017

We report the case of a 25‐year‐old female with renal arteriovenous fistula and pseudoaneurysm (PA) formation following renal core‐needle biopsy, treated successfully by ultrasound‐guided percutaneous embolization with autologous blood clot injection. After inserting a 15‐gauge needle within the PA sac, 10 ml of blood was retrieved from the sac, and then reinjected into the PA as well as in the needle tract after the obtained blood completely clotted. The procedure was completed by manual compression of the flank. Follow‐up sonographic examinations revealed no complication, and the PA size reduced gradually over time due to fibrotic shrinkage. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:592–596, 2017
A case of prenatally detected left isomerism and hemiazygos continuation of inferior vena cava
Authors: Moradi Behnaz , Moosavi Najme‐Sadat , Kazemi Mohamad Ali , Tahmasebpour Ahmad‐Reza , Fattahi Masrour Farzaneh
Published: March 2017

Heterotaxy syndromes are defined as the disorders that involve abnormal arrangement of viscera. We present a case of prenatally diagnosed left isomerism in a 30‐year‐old primigravida woman referred to our hospital for complex cardiac abnormality. Sonographic findings included heart block, unbalanced atrioventricular septal defect, interruption of the inferior vena cava with hemiazygos continuation, double superior vena cava, a right‐sided stomach, and biliary atresia. The hemiazygos vein drained into the right atrium by the persistent left superior vena cava. This type of inferior vena cava interruption and continuation is rarely reported in prenatally detected cases of left isomerism. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:430–433, 2017
Enhanced adhesion of Streptococcus mutans to hydroxyapatite after exposure to saliva
Authors: Spengler Christian , Thewes Nicolas , Nolle Friederike , Faidt Thomas , Umanskaya Natalia , Hannig Matthias , Bischoff Markus , Jacobs Karin
Published: March 2017

Streptococcus mutans cells form robust biofilms on human teeth and are strongly related to caries incidents. Hence, understanding the adhesion of S. mutans in the human oral cavity is of major interest for preventive dentistry. In this study, we report on atomic force microscopy–based single‐cell force spectroscopy measurements of S. mutans cells to hydroxyapatite surfaces. We observe for almost all measurements a significant difference in adhesion strength for S. mutans as well as for Staphylococcus carnosus cells. However, the increase in adhesion strength after saliva exposure is much higher for S. mutans cells compared to S. carnosus cells. Our results demonstrate that S. mutans cells are well adapted to their natural environment, the oral cavity. This ability promotes the biofilm‐forming capability of that species and hence the production of caries‐provoking acids. In consequence, understanding the fundamentals of this mechanism may pave a way towards more effective caries‐reducing techniques.
Fast bilateral breast coverage with high spectral and spatial resolution (HiSS) MRI at 3T
Authors: Medved Milica , Li Hui , Abe Hiroyuki , Sheth Deepa , Newstead Gillian M. , Olopade Olufunmilayo I. , Giger Maryellen L. , Karczmar Gregory S.
Published: March 2017

Purpose

To develop and assess a full‐coverage, sensitivity encoding (SENSE)‐accelerated breast high spatial and spectral resolution (HiSS) magnetic resonance imaging (MRI) within clinically reasonable times as a potential nonenhanced MRI protocol for breast density measurement or breast cancer screening.

Materials and Methods

Sixteen women with biopsy‐proven cancer or suspicious lesions, and 13 women who were healthy volunteers or were screened for breast cancer, received 3T breast MRI exams, including SENSE‐accelerated HiSS MRI, which was implemented as a submillimeter spatial resolution echo‐planar spectroscopic imaging (EPSI) sequence. In postprocessing, fat and water resonance peak height and integral images were generated from EPSI data. The postprocessing software was custom‐designed, and new algorithms were developed to enable processing of whole‐coverage axial HiSS datasets. Water peak height HiSS images were compared to pre‐ and postcontrast T1‐weighted images. Fat suppression was quantified as parenchymal‐to‐suppressed‐fat signal ratio in HiSS water peak height and nonenhanced T1‐weighted images, and artifact levels were scored.

Results

Approximately a 4‐fold decrease in acquisition speed, with a concurrent 2.5‐fold decrease in voxel size, was achieved, with low artifact levels, and with spectral signal‐to‐noise ratio (SNR) of 45:1. Fat suppression was 1.9 times more effective (P < 0.001) in HiSS images than in T1‐weighted images (SPAIR), and HiSS images showed higher SNR in the axilla. HiSS MRI visualized 10 of 13 malignant lesions identified on dynamic contrast‐enhanced (DCE)‐MRI, and did not require skin removal in postprocessing to generate maximum intensity projection images.

Conclusion

We demonstrate full‐coverage, SENSE‐accelerated breast HiSS MRI within clinically reasonable times, as a potential protocol for breast density measurement or breast cancer screening.

Level of Evidence: 2

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2017;46:1341–1348.
Revealing topoclimatic heterogeneity using meteorological station data
Authors: Aalto Juha , Riihimäki Henri , Meineri Eric , Hylander Kristoffer , Luoto Miska
Published: March 2017

Climate is a crucial driver of the distributions and activity of multiple biotic and abiotic processes, and thus high‐quality and high–resolution climate data are often prerequisite in various environmental research. However, contemporary gridded climate products suffer critical problems mainly related to sub‐optimal pixel size and lack of local topography‐driven temperature heterogeneity. Here, by integrating meteorological station data, high‐quality terrain information and multivariate modelling, we aim to explicitly demonstrate this deficiency. Monthly average temperatures (1981–2010) from Finland, Sweden and Norway were modelled using generalized additive modelling under (1) a conventional (i.e. considering geographical location, elevation and water cover) and (2) a topoclimatic framework (i.e. also accounting for solar radiation and cold‐air pooling). The performance of the topoclimatic model was significantly higher than the conventional approach for most months, with bootstrapped mean R2 for the topoclimatic model varying from 0.88 (January) to 0.95 (October). The estimated effect of solar radiation was evident during summer, while cold air pooling was identified to improve local temperature estimates in winter. The topoclimatic modelling exposed a substantial temperature heterogeneity within coarser landscape units (>5 °C/1 km−2 in summer) thus unveiling a wide range of potential microclimatic conditions neglected by the conventional approach. Moreover, the topoclimatic model predictions revealed a pronounced asymmetry in average temperature conditions, causing isotherms during summer to differ several hundreds of metres in altitude between the equator and pole facing slopes. In contrast, cold‐air pooling in sheltered landscapes lowered the winter temperatures ca. 1.1 °C/100 m towards the local minimum altitude. Noteworthy, the analysis implies that conventional models produce biassed predictions of long‐term average temperature conditions, with errors likely to be high at sites associated with complex topography.
Diminished bone regeneration after debridement of posttraumatic osteomyelitis is accompanied by altered cytokine levels, elevated B cell activity, and increased osteoclast activity
Authors: Wagner Johannes M. , Jaurich Henriette , Wallner Christoph , Abraham Stephanie , Becerikli Mustafa , Dadras Mehran , Harati Kamran , Duhan Vikas , Khairnar Vishal , Lehnhardt Marcus , Behr Björn
Published: March 2017

Osteomyelitis is a frequent consequence of open fractures thus representing a common bone infection with subsequent alteration of bone regeneration. Impaired bone homeostasis provokes serious variations in the bone remodeling process, thereby involving multiple inflammatory cytokines to activate bone healing. Our previously established mouse model of posttraumatic osteomyelitis provides the chance to study regulation of selected cytokines after surgical debridement of osteomyelitis thus illustrating the course of initial infectious recovery. An inflammatory cytokine array revealed specifically upregulated cytokines in debrided animals after bone infection, that were verified by Western blot analysis, identifying increased levels of CCL2, CCL3, and CXCL2. Increased osteoclastogenesis after debridement of osteomyelitis was demonstrated by Calcitonin‐receptor and RANKL detection via immunohistochemical and ‐fluorescence stainings. The substantial protein analysis was complemented by uncovering diminished osteogenesis and proliferation in debrided group, tracking Osteocalcin, RUNX2, and PCNA expression. Interestingly TNF‐α expression seemed to have no effect on altered bone regeneration after bone infection. Additional flow cytometry analysis proved elevated B cell activity, subsequently increased osteoclast activity and accelerated bone resorption. Based on the variety of severely altered cytokines, we propose a RANKL‐dependent osteoclastogenesis after debridement of osteomyelitis coinciding with elevated B cells and simultaneously decreased osteogenesis. A comprehensive understanding of these mechanisms provides new therapeutic options of osteomyelitis cure and is of great importance in prospective medical treatment. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2425–2434, 2017.
Evaluation of model‐generated vertical profiles of meteorological variables: method and initial results
Authors: Cogan J.
Published: March 2017

Meteorological centres compare global and large‐scale regional model output versus radiosonde data more or less continuously for specific models and also make inter‐model comparisons. They normally provide comparisons of meteorological variables at standard pressure levels, and similar comparisons for finer‐scale models may be found as output from field tests and other experiments. Additional means to evaluate vertical profiles derived from model output more fully should help provide a more complete evaluation of model output compared with observations. Here, two versions of a program to produce vertical profiles of meteorological variables in terms of user input heights or pressure levels are developed, and integrated mean value profiles of the variables for layers defined by those heights or pressures are generated. Output profiles were entered into spreadsheets for calculation of the derived variables of density and vector wind speed. The level and mean layer values from the Weather Research and Forecasting model (version 3.6.1) were compared with co‐incident World Meteorological Organization radiosonde observation data and the differences were computed for several variables. The methods developed here may be used for a variety of model‐generated and observed vertical profiles with only minimal changes, primarily to the input function.
Improved olefinic fat suppression in skeletal muscle DTI using a magnitude‐based dixon method
Authors: Burakiewicz Jedrzej , Hooijmans Melissa T. , Webb Andrew G. , Verschuuren Jan J.G.M. , Niks Erik H. , Kan Hermien E.
Published: March 2017

Purpose

To develop a method of suppressing the multi‐resonance fat signal in diffusion‐weighted imaging of skeletal muscle. This is particularly important when imaging patients with muscular dystrophies, a group of diseases which cause gradual replacement of muscle tissue by fat.

Theory and Methods

The signal from the olefinic fat peak at 5.3 ppm can significantly confound diffusion‐tensor imaging measurements. Dixon olefinic fat suppression (DOFS), a magnitude‐based chemical‐shift–based method of suppressing the olefinic peak, is proposed. It is verified in vivo by performing diffusion tensor imaging (DTI)‐based quantification in the lower leg of seven healthy volunteers, and compared to two previously described fat‐suppression techniques in regions with and without fat contamination.

Results

In the region without fat contamination, DOFS produces similar results to existing techniques, whereas in muscle contaminated by subcutaneous fat signal moved due to the chemical shift artefact, it consistently showed significantly higher (P = 0.018) mean diffusivity (MD). Because fat presence lowers MD, this suggests improved fat suppression.

Conclusion

DOFS offers superior fat suppression and enhances quantitative measurements in the muscle in the presence of fat. DOFS is an alternative to spectral olefinic fat suppression. Magn Reson Med 79:152–159, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Possible protective role of silybin against polymyxin E‐induced toxic effect in rat kidneys: A biochemical approach
Authors: Hassan Sherif S. , Thomann Charity , Ettarh Rajunor , Ahmad Zulfiqar
Published: March 2017

AIMS

Polymyxin E was used for treating gram‐negative bacterial infections but not recently for fear of its nephrotoxicity. Silybin has potential to counteract nephrotoxicity; however, few studies have investigated its protective effect on the kidney in an animal model. The purpose of the present study was to assess whether silybin could decrease elevated urine and serum renal biochemical markers induced by polymyxin E in rat kidney.

METHODS

Forty rats were divided randomly into four groups of 10 rats: control (I), vehicle (II), treatment (III, using polymyxin E), and protection (IV, using silybin and polymyxin E). Urine was collected daily for 7 days to test for N‐acetyl‐beta‐D‐glucosaminidase (NAG). Serum was collected after euthanizing the rats on day 7 to test kidney functions.

RESULTS Group III had significant increases in NAG (all P < 0.001) compared with the other groups, but no differences were found between the other groups. Significant differences in kidney functions were found between Group III and Groups I and II, and between Group IV and Groups I and II (all P < 0.001). No differences were found between Groups III and IV.

CONCLUSIONS

Group III results suggested an affection of the renal glomeruli and tubules, and Group IV results suggested a possible protective effect of silybin against polymyxin E‐induced nephrotoxicity. Additional studies are recommended that use different doses of silybin for Groups III and IV to test for statistical differences for kidney functions and that test the protective effect of silybin against nephrotoxicity induced by polymyxin E in humans.
Study on the multiple cyclization reactions and the formed structures in poly(acrylonitrile‐co‐itaconic acid) copolymers during thermal treatment
Authors: Fu Zhongyu , Liu Baijun , Sun Lihao , Deng Yunjiao , Zhang Huixuan
Published: March 2017

The present work provided some in‐depth understanding on the role of itaconic acid (IA) in the structural evolution of poly(acrylonitrile‐co‐itaconic acid) (PAI) polymers and the formed cyclic structures during thermal treatment. As the increasing content of IA, the cyclization initiated by the ionic mechanism increased with the less β‐amino nitrile formed and the higher extent of cyclization. The IA comonomer initiated multiple cyclization reactions, namely, the first ionic cyclization and the second ionic cyclization, by the jump transportation of activation species between different PAI chains during thermal treatment. The times of the jump transportation of activation species was about two or three at 250°C. The presence of IA comonomer promoted the formation of long sequence cyclic structures rather than isolated cyclic structure under non‐oxidative condition. The thermal stability of PAI was improved by the more and better cyclic structures and the crosslinking structures caused by the jump transportation of activation species, which reasonably resulted in a better graphitic lattice during the carbonization. Copyright © 2017 John Wiley & Sons, Ltd.
The reactivity of the 5‐formylcytosine with hydroxyl radical: A theoretical perspective
Authors: Jin Lingxia , Lü Mengdan , Zhao Caibin , Min Suotian , Zhang Tianlei , Zhang Qiang
Published: March 2017

Hydroxyl radical (•OH) damages DNA/RNA by attacking pyrimidine nucleobases through the addition reaction and H‐atom abstraction. It may attack on the new cytosine derivative (5‐formylCytosine [5‐fCyt]) causing DNA oxidative damage, whereas the study of the related mechanism is still in its infancy. In the present work, 2 distinct mechanisms of •OH‐mediated 5‐fCyt at the complete basis set methods (CBS‐QB3) and CBS‐QB3/polarized continuum model approaches have firstly been explored, the addition reaction (paths R1 ~ R3) and the abstraction reaction (paths R4 ~ R6), respectively, and it shows that the addition of •OH to the C5═C6 double bond of 5‐fCyt is more favourable than other reactions, indicating that the •OH addition to the C5 and C6 atoms have relatively high probability to happen. The proportion of the C5 and C6 adducts is large and may be detectable experimentally, which is in agreement with the conclusions of •OH‐mediated cytosine reaction reported experimentally and theoretically. These hint that the new DNA base (5‐fCyt) is easily damaged when exposed the surrounding of •OH environment. Therefore, the reducing free radical production or the addition of some antioxidants should be taken in embryonic stem cells to resistance DNA damage. Our results provide some evidences between 5‐fCyt and tumor development for the experimental scientists.
Output feedback hierarchical control for nonlinear systems
Authors: Yang Kaihong , Ji Haibo
Published: March 2017

In this paper, we address the problem of hierarchical control for nonlinear systems and design two dynamic output feedback hierarchical control laws in a semiglobal sense and in a global sense, respectively. With the controllers applied to a class of nonlinear systems, some transient and steady properties of the system output trajectories can be satisfied simultaneously. Furthermore, the corresponding result in the global sense for linear systems is naturally derived. Finally, the effectiveness of our approach is illustrated by a single‐link robot arm system. Copyright © 2017 John Wiley & Sons, Ltd.
Characterization of the electronic structure and thermal stability of HfO2/SiO2/Si gate dielectric stack
Authors: Duan T. L. , Pan L. , Zhang Z. , Tok E. S. , Pan J. S.
Published: March 2017

X‐ray photoelectron spectroscopy was used to investigate thermal stability of HfO2 on SiO2/Si substrate prepared by atomic layer deposition, followed by annealing at different temperature. Hf silicate and Hf silicide are formed at the interface of HfO2 and SiO2 during deposition. The Hf silicide disappears, while the amount of the Hf silicate is intensified after post‐deposition annealing treatment at 400 °C. Phase separation of the Hf silicate layer occurs when the annealing temperature is over 400 °C, resulting in the Hf silicate decomposition into Si and Hf oxides. Moreover, crystallization at high temperature leads to grain boundaries formation, which deteriorates the gate leakage current, as observed by the electrical measurements. The similar annealing temperature dependence of both internal electric field and the amount of Hf silicate implies that the Hf silicate plays a key role in building up the internal electric field, which is attributed to generation of oxygen vacancies (Vo) in the Hf silicate layer. Copyright © 2017 John Wiley & Sons, Ltd.
On the Catalytic Activity of Pt Supported by Graphyne in the Oxidation of Ethanol
Authors: Tian Ge , Qi Zhongnan , Ma Wanyong , Wang Yixuan
Published: March 2017

The adsorptions of Pt clusters on β‐ and γ‐graphyne (β‐GY, γ‐GY), graphdiyne (GDY), and graphene (GP) were extensively investigated with density functional theory. Ethanol adsorption and its partial oxidation on the Pt supported by the GY and GP were then explored to address the influence of the supporting materials on the activity of Pt nanoclusters in ethanol oxidation. Among the examined adsorption sites such as the hollow, Csp‐Csp, and Csp‐Csp2 bonds, the hollow site consisting of multiple triple bonds is the most attractive one to adsorb Pt and Pt4 regardless of β‐GY, γ‐GY, and GDY. The binding of Pt4 to the GDY is slightly stronger than those of β‐GY and γ‐GY (binding energy: −4.08 vs −3.64 and −3.73 eV). It is remarkable that the adsorption of Pt4 on GY is 2–3 times stronger than that on GP (‐3.6‐4.1 vs −1.3 eV), showing that the GY and GDY are better substrates than the GP for the stability of Pt clusters. Furthermore, the potential energy profiles for the oxidation of ethanol show that in spite of the higher energy barrier for the adsorbed ethanol on Pt4 supported by γ‐GY than by GP (1.54 vs 1.19 eV), the dehydrogenation intermediate and product of ethanol on Pt‐graphyne are more stable than that on Pt‐graphene, suggesting that graphyne is thermodynamically more favorable than graphene as a substrate for the Pt catalyst.
Teaching and research at a large university: Case studies of science professors
Authors: Robert Jenay , Carlsen William S.
Published: March 2017

Current STEM workforce issues and retention problems faced by postsecondary STEM education have renewed research efforts in this arena. A review of literature on STEM professors indicates that although this population reports difficulties integrating teaching and research responsibilities, there have not yet been any qualitative studies conducted to deeply investigate the complexities of managing teaching, research, and service. This work utilized a set of four phenomenological case studies conducted over a 10‐month period to address the following research question: How do individuals in a sample of tenure‐track science professors prioritize teaching among their other professional roles and responsibilities? Contrary to literature speculation, the results of this study indicate that the participants make decisions about the way they allocate limited time in an unlimited work environment based on their intrinsic, personal career goals and aspirations and appear to be only minimally affected by external pressures to “prioritize research over teaching.” Furthermore, all of the participants in the study indicated that other than research training, they received little to no preparation for their jobs. These findings provide discipline‐based education researchers with points of interest for further study and provide professional development stakeholders with data for the design of educational support programs. © 2017 Wiley Periodicals, Inc. J Res Sci Teach 54: 937–960, 2017