bluuebunny/crossref_metadata_2025 huggingface dataset:
Small RNA and degradome deep sequencing reveals drought‐and tissue‐specific micrornas and their important roles in drought‐sensitive and drought‐tolerant tomato genotypes
Authors: Candar‐Cakir Bilgin , Arican Ercan , Zhang Baohong
Published: February 2016

Drought stress has adverse impacts on plant production and productivity. MicroRNAs (miRNAs) are one class of noncoding RNAs regulating gene expression post‐transcriptionally. In this study, we employed small RNA and degradome sequencing to systematically investigate the tissue‐specific miRNAs responsible to drought stress, which are understudied in tomato. For this purpose, root and upground tissues of two different drought‐responsive tomato genotypes (Lycopersicon esculentum as sensitive and L. esculentum var. cerasiforme as tolerant) were subjected to stress with 5% polyethylene glycol for 7 days. A total of 699 conserved miRNAs belonging to 578 families were determined and 688 miRNAs were significantly differentially expressed between different treatments, tissues and genotypes. Using degradome sequencing, 44 target genes were identified associated with 36 miRNA families. Drought‐related miRNAs and their targets were enriched functionally by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. Totally, 53 miRNAs targeted 23 key drought stress‐ and tissue development‐related genes, including DRP (dehydration‐responsive protein), GTs (glycosyltransferases), ERF (ethylene responsive factor), PSII (photosystem II) protein, HD‐ZIP (homeodomain‐leucine zipper), MYB and NAC‐domain transcription factors. miR160, miR165, miR166, miR171, miR398, miR408, miR827, miR9472, miR9476 and miR9552 were the key miRNAs functioning in regulation of these genes and involving in tomato response to drought stress. Additionally, plant hormone signal transduction pathway genes were differentially regulated by miR169, miR172, miR393, miR5641, miR5658 and miR7997 in both tissues of both sensitive and tolerant genotypes. These results provide new insight into the regulatory role of miRNAs in drought response with plant hormone signal transduction and drought‐tolerant tomato breeding.
Does Order of Application of Emollient and Topical Corticosteroids Make a Difference in the Severity of Atopic Eczema in Children?
Authors: Ng Su Yuen , Begum Sabeera , Chong Sze Yee
Published: February 2016

Background

Atopic eczema (AE) is a common chronic inflammatory skin disorder in children, with emollients and topical corticosteroids (TCSs) commonly prescribed as treatment. There is no published guidance on the correct order of application of emollient and TCS in children with AE.

Objective

The objective of this study was to determine whether the order of application of emollient and TCS makes a difference in the severity of AE in children.

Methods

Forty‐six patients ages 4 months to 5 years with moderate to severe AE were randomized to two groups: group A applied emollient followed by TCS 15 minutes later twice daily, and group B applied TCS followed by emollient 15 minutes later twice daily for 2 weeks.

Results

There was no statistically significant difference in the Eczema Area and Severity Index (EASI) score, percentage of body surface area (BSA) affected, or itch score between groups A and B (p > 0.05). Group A had statistically significant improvement in the EASI score, percentage BSA affected, and itch score from baseline to weeks 1 and 2; group B demonstrated statistically significant improvement only in the EASI score from baseline to week 1 and in itch score from baseline to week 2. There was no difference in adverse events between the groups.

Conclusion

This study suggests that the order of application of emollient and TCS does not matter in the treatment of AE in children and that parents can apply topical medications in whichever order they prefer.
Spillover Effects of Emotional Labor in Customer Service Encounters Toward Coworker Harming: A Resource Depletion Perspective
Authors: Deng Hong , Walter Frank , Lam Catherine K. , Zhao Helen H.
Published: February 2016

This research examines how the implications of emotional labor can transfer from customer encounters to coworker interactions using temporally lagged data from a sample of frontline service employees. The results show that surface acting in customer service encounters is positively, and deep acting is negatively, related to ego depletion. Employees’ ego depletion, in turn, is positively associated with their interpersonally harmful behavior toward coworkers. Hence, ego depletion appears as a mediating variable that translates the implications of distinct emotional labor strategies into coworker harming. Moreover, emotion regulation self‐efficacy moderates the role of surface acting. The positive indirect relationship between surface acting and coworker harming, via ego depletion, is buffered among employees with higher emotion regulation self‐efficacy. These findings shed new light on the complex and far‐reaching consequences of emotional labor. We demonstrate the relevance of emotional labor to third parties not directly involved in customer service encounters and highlight important mediators and boundary conditions of these indirect relations.
Living donor domino liver transplantation using a maple syrup urine disease donor: A case series of three children – The first report from Japan
Authors: Matsunami Masatoshi , Fukuda Akinari , Sasaki Kengo , Uchida Hajime , Shigeta Takanobu , Hirata Yoshihiro , Kanazawa Hiroyuki , Horikawa Reiko , Nakazawa Atsuko , Suzuki Tatsuya , Mizuta Koichi , Kasahara Mureo
Published: February 2016

As the priority of LD‐Domino LT is the safety of the first recipient, limitations and technical difficulties in the second recipient often occur. The most technically challenging part of LD‐Domino LT is the reconstruction of the vessels. For the reconstruction of HVs, the native HVs were exteriorized as far as possible using a CUSA because longer extensive HVs are essential for facilitating the reconstruction. At the back table, the HVs of the domino graft were sutured together, and the single cuff of the HVs was anastomosed to the IVC by joining the orifices. The HAs, the presence of insufficient length, and multiple vessels in the whole liver rendered the reconstruction more difficult. We determined the dividing sites of the vessels according to the preoperative 3D‐CT findings obtained in two institutions. This is the first case series using grafts in DLT obtained from LDLT for patients with MSUD between two institutions. In conclusion, LD‐Domino LT is a safe and feasible therapeutic option to expand the donor pool by technical refinement in the reconstruction of the second recipient. Further studies with a greater accumulation of patients and a longer follow‐up will be necessary to establish LD‐Domino LT using an MSUD donor.
Management of behavioural symptoms of dementia in a specialized unit care
Authors: Saidlitz Pascal , Sourdet Sandrine , Voisin Thierry , Vellas Bruno
Published: February 2016

Background

In France, the Alzheimer Plan 2008–2012 has enabled the development of units specialized in managing the behavioural and psychological disorders found in cognitive pathologies, with an emphasis on both pharmacological and non‐pharmacological treatments. The aim of this study was to analyze the evolution of behavioural symptoms, autonomy, and psychotropic drug prescriptions at a cognitive and behavioural unit in Toulouse, France.

Methods

Prospective study, with systematic analyze of data for patients hospitalized in a cognitive and behavioral unit.

Results

This 2‐year study included 199 patients. Behavioural symptoms were significantly improved during the follow‐up period and remained so after discharge. Autonomy, especially in walking, was not altered. The prescription of psychotropic drugs, such as neuroleptics, was significantly lower at discharge.

Conclusion

This study showed the effectiveness of overall care, with an emphasis on pharmacological and non‐pharmacological treatments, in managing disruptive behavioural symptoms in a specialized unit.
Treat your suppliers right! Aligning strategic innovation orientation in captive supplier relationships with relational and transactional governance mechanisms
Authors: Clauss Thomas , Spieth Patrick
Published: February 2016

Buyer‐supplier relationships are regarded as a source of competitive advantage, as suppliers can contribute valuable but imperfectly tradable resources. To coordinate these resources in the course of joint value creation and mitigate the risks of opportunism, buyers are required to establish transactional and relational governance mechanisms. While recent research showed that these mechanisms are intertwined with each other, little is known about the effects of different governance mechanisms in relationships with captive suppliers. Especially in case of captive suppliers, which are highly dependent on the buyer, the governance approach of the buyer affects the relationship and the supplier on a long‐term base. Based on unique data of 101 suppliers in the aviation industry, we show that transactional and relational governance mechanisms exert different effects on the efficiency and effectiveness of relationships with captive suppliers. While transactional governance is primarily suited to foster buyer‐supplier efficiency (e.g. cost or lead time reduction), relational governance strengthens buyer‐supplier effectiveness (e.g. product customization or joint innovation). Additionally, the choice of a governance mechanism indirectly affects the strategic innovation orientation of captive suppliers. Focusing on buyer‐supplier effectiveness stimulates strategic innovation orientation of captive suppliers; high buyer‐supplier efficiency leads to opposite effects. Our paper emphasizes that misalignment of governance mechanisms and the objective of buyer‐supplier relationships can limit strategic innovation orientation.
Modeling of Salmonella Contamination in the Pig Slaughterhouse
Authors: Swart A. N. , Evers E. G. , Simons R. L. L. , Swanenburg M.
Published: February 2016

In this article we present a model for Salmonella contamination of pig carcasses in the slaughterhouse. This model forms part of a larger QMRA (quantitative microbial risk assessment) on Salmonella in slaughter and breeder pigs, which uses a generic model framework that can be parameterized for European member states, to describe the entire chain from farm‐to‐consumption and the resultant human illness. We focus on model construction, giving mathematical formulae to describe Salmonella concentrations on individual pigs and slaughter equipment at different stages of the slaughter process. Variability among individual pigs and over slaughterhouses is incorporated using statistical distributions, and simulated by Monte Carlo iteration. We present the results over the various slaughter stages and show that such a framework is especially suitable to investigate the effect of various interventions. In this article we present the results of the slaughterhouse module for two case study member states. The model outcome represents an increase in average prevalence of Salmonella contamination and Salmonella numbers at dehairing and a decrease of Salmonella numbers at scalding. These results show good agreement when compared to several other QMRAs and microbiological studies.
An Approach to Cluster EU Member States into Groups According to Pathways of Salmonella in the Farm‐to‐Consumption Chain for Pork Products
Authors: Vigre Håkan , Domingues Ana Rita Coutinho Calado , Pedersen Ulrik Bo , Hald Tine
Published: February 2016

The aim of the project as the cluster analysis was to in part to develop a generic structured quantitative microbiological risk assessment (QMRA) model of human salmonellosis due to pork consumption in EU member states (MSs), and the objective of the cluster analysis was to group the EU MSs according to the relative contribution of different pathways of Salmonella in the farm‐to‐consumption chain of pork products. In the development of the model, by selecting a case study MS from each cluster the model was developed to represent different aspects of pig production, pork production, and consumption of pork products across EU states. The objective of the cluster analysis was to aggregate MSs into groups of countries with similar importance of different pathways of Salmonella in the farm‐to‐consumption chain using available, and where possible, universal register data related to the pork production and consumption in each country. Based on MS‐specific information about distribution of (i) small and large farms, (ii) small and large slaughterhouses, (iii) amount of pork meat consumed, and (iv) amount of sausages consumed we used nonhierarchical and hierarchical cluster analysis to group the MSs.

The cluster solutions were validated internally using statistic measures and externally by comparing the clustered MSs with an estimated human incidence of salmonellosis due to pork products in the MSs. Finally, each cluster was characterized qualitatively using the centroids of the clusters.
Failing to Fix What is Found: Risk Accommodation in the Oil and Gas Industry
Authors: Stackhouse Madelynn R. D. , Stewart Robert
Published: February 2016

The present program of research synthesizes the findings from three studies in line with two goals. First, the present research explores how the oil and gas industry is performing at risk mitigation in terms of finding and fixing errors when they occur. Second, the present research explores what factors in the work environment relate to a risk‐accommodating environment. Study 1 presents a descriptive evaluation of high‐consequence incidents at 34 oil and gas companies over a 12‐month period (N = 873), especially in terms of those companies’ effectiveness at investigating and fixing errors. The analysis found that most investigations were fair in terms of quality (mean = 75.50%), with a smaller proportion that were weak (mean = 11.40%) or strong (mean = 13.24%). Furthermore, most companies took at least one corrective action for high‐consequence incidents, but few of these corrective actions were confirmed as having been completed (mean = 13.77%). In fact, most corrective actions were secondary interim administrative controls (e.g., having a safety meeting) rather than fair or strong controls (e.g., training, engineering elimination). Study 2a found that several environmental factors explain the 56.41% variance in safety, including management's disengagement from safety concerns, finding and fixing errors, safety management system effectiveness, training, employee safety, procedures, and a production‐over‐safety culture. Qualitative results from Study 2b suggest that a compliance‐based culture of adhering to liability concerns, out‐group blame, and a production‐over‐safety orientation may all impede safety effectiveness.
Doing More Than Caring About Quality
Authors: Maddux Franklin W.
Published: February 2016

The treatment of chronically ill patients with end stage renal disease (ESRD) receiving dialysis therapies has advanced greatly over the years and accomplished many successes in prolonging the life of patients with ESRD, yet has had considerable failures due to the inability to compensate for all functions of the kidneys. In addition, the focus to achieve quality goals for laboratories and vascular access measures may indicate a good quality of care from providers, but meeting these clinical and physiological goals may not fully maximize individual benefit to a patient, may not be aligned with the patient's care goals, and could conceivably impact negatively the patient's experience of care and quality of life. The age of individualized patient centered care is forthcoming with advancements in technology and our understanding of the treatment of renal diseases. The future holds promise for enhancing the quality provided to each patient but will require nephrologists to overcome numerous hurdles. This article provides an opinion on principles that may fundamentally improve the quality of renal disease care in the future and represents themes that can enhance quality, safety, and efficiency in the health care delivery system. It is believed that quality measured from a patient centric perspective will shift the treatment for these chronic disorders to better meet each patient's needs and goals, while evolving an enhanced delivery system for the care of all ESRD patients.
Reappraisal of Precambrian sheet‐braided rivers: Evidence for 1·9 Ga deep‐channelled drainage
Authors: Ielpi Alessandro , Rainbird Robert H.
Published: February 2016

The repetitive sedimentology of many Precambrian sheet‐dominated fluvial sandstones favoured their attribution to unconfined depositional processes. This article presents outcrop evidence for deep‐channelled drainage in the 1·9 Ga Burnside River Formation of Kilohigok Basin, Arctic Canada. On the ground, sheet‐like sandbodies with ubiquitous cross‐bedding are at first consistent with classic, unconfined depositional models. However, satellite and oblique‐aerial imagery of sections up to 15 km wide and 500 m thick reveals the occurrence of incised palaeovalleys hosting clustered, kilometre‐scale, channel bodies with attached large foreset bars pointing to downstream‐lateral accretion, sand sheets with aspect ratios (i.e. width to thickness) as high as 2500, and scattered aeolian intervals. The genetic association of these architectural elements points to aggradational fluvial piedmonts composed of low‐relief unit bars generated by braidplain channels several metres deep. Preservation of aeolianites was facilitated by fluctuating groundwater table and accommodation. Fluvial piedmonts were transected by weakly sinuous channel belts up to 25 m deep and characterized by through‐going or tributary planform. Aspect ratios comparable with those of late Palaeozoic to modern braided channels disprove the inference that all Precambrian streams readily widened in response to increased discharge. Previous facies models for large‐scale Precambrian sheet‐braided rivers failed to depict entire channel forms, possibly because they could not be resolved by ground‐based observations. Based on their limited geomorphic variability and abundance of architectural elements with very high aspect ratios, this study recommends that large sheet‐braided fluvial systems should still be considered separately from their post‐Silurian (i.e. vegetated) braided counterparts. Parallels between sheet‐braided and modern dryland rivers do not, however, reconcile with the deep, perennial, channelized processes described here. Yet, distal sand‐bed and perennial reaches of modern sandur plains remain the closest analogue to sheet‐braided rivers. This conjecture contradicts the assumption that all Precambrian rivers were prone to simulate seasonal behaviours independently from their actual climate regime.
Economic Dependency and HIV/AIDS Prevalence in the Developing World: A Comparative, Longitudinal Analysis
Authors: Maynard Gary , Ong Corinne
Published: February 2016

The HIV/AIDS pandemic has plagued global society for over three decades. While breakthroughs in antiretroviral treatments (ART) have proven effective in suppressing the virus and HIV/AIDS intervention outreach have widened, epidemic control remains unevenly achieved among countries. At least 95 percent of HIV/AIDS sufferers originate from developing countries. Dependency theory suggests that developing countries' reliance on debt, trade, and foreign investments pose negative effects on their populations' health. Guided by dependency theory's propositions, this cross‐national study assesses whether increasing dependence on trade, debt, and foreign direct investment potentially increases adult HIV prevalence in developing countries from 1989 to 2012. Using a sample of over 80 nations, we perform a two‐way fixed‐effects OLS regression to evaluate the impact of increasing debt, trade, and foreign investment on adult HIV prevalence. Total debt, short‐term debt, external debt, and GDP were found to increase HIV prevalence. The findings for debt support dependency theory's predictions concerning the ramifications of global economic inequality on HIV/AIDS prevalence.
Twin anchors of the soybean isoflavonoid metabolon: evidence for tethering of the complex to the endoplasmic reticulum by IFS and C4H
Authors: Dastmalchi Mehran , Bernards Mark A. , Dhaubhadel Sangeeta
Published: February 2016

Isoflavonoids are specialized plant metabolites, almost exclusive to legumes, and their biosynthesis forms a branch of the diverse phenylpropanoid pathway. Plant metabolism may be coordinated at many levels, including formation of protein complexes, or ‘metabolons’, which represent the molecular level of organization. Here, we have confirmed the existence of the long‐postulated isoflavonoid metabolon by identifying elements of the complex, their subcellular localizations and their interactions. Isoflavone synthase (IFS) and cinnamate 4–hydroxylase (C4H) have been shown to be tandem P450 enzymes that are anchored in the ER, interacting with soluble enzymes of the phenylpropanoid and isoflavonoid pathways (chalcone synthase, chalcone reductase and chalcone isomerase). The soluble enzymes of these pathways, whether localized to the cytoplasm or nucleus, are tethered to the ER through interaction with these P450s. The complex is also held together by interactions between the soluble elements. We provide evidence for IFS interaction with upstream and non‐consecutive enzymes. The existence of such a protein complex suggests a possible mechanism for flux of metabolites into the isoflavonoid pathway. Further, through interaction studies, we identified several candidates that are associated with GmIFS2, an isoform of IFS, in soybean hairy roots. This list provides additional candidates for various biosynthetic and structural elements that are involved in isoflavonoid production. Our interaction studies provide valuable information about isoform specificity among isoflavonoid enzymes, which may guide future engineering of the pathway in legumes or help overcome bottlenecks in heterologous expression.
Brown adipose tissue activation as measured by infrared thermography by mild anticipatory psychological stress in lean healthy females
Authors: Robinson Lindsay J. , Law James M. , Symonds Michael E. , Budge Helen
Published: February 2016

New Findings

What is the central question of this study?

Does psychological stress, which is known to promote cortisol secretion, simultaneously activate brown adipose tissue function in healthy adult females?

What is the main finding and its importance?

One explanation for the pronounced differences in brown adipose tissue function between individuals lies in their responsiveness to psychological stress and, as such, should be taken into account when examining its in vivo stimulation.

Brown adipose tissue (BAT) has been implicated in the pathogenesis of obesity, type 2 diabetes and the metabolic syndrome and is a potential therapeutic target. Brown adipose tissue can have a significant impact on energy balance and glucose homeostasis through the action of uncoupling protein 1, dissipating chemical energy as heat following neuroendocrine stimulation. We hypothesized that psychological stress, which is known to promote cortisol secretion, would simultaneously activate BAT at thermoneutrality. Brown adipose tissue activity was measured using infrared thermography to determine changes in the temperature of the skin overlying supraclavicular BAT (TSCR). A mild psychological stress was induced in five healthy, lean, female, Caucasian volunteers using a short mental arithmetic (MA) test. The TSCR was compared with a repeated assessment, in which the MA test was replaced with a period of relaxation. Although MA did not elicit an acute stress response, anticipation of MA testing led to an increase in salivary cortisol, indicative of an anticipatory stress response, that was associated with a trend towards higher absolute and relative TSCR. A positive correlation between TSCR and cortisol was found during the anticipatory phase, a relationship that was enhanced by increased cortisol linked to MA. Our findings suggest that subtle changes in the level of psychological stress can stimulate BAT, findings that may account for the high variability and inconsistency in reported BAT prevalence and activity measured by other modalities. Consistent assessment of this uniquely metabolic tissue is fundamental to the discovery of potential therapeutic strategies against metabolic disease.
Reactive oxygen/nitrogen species and contractile function in skeletal muscle during fatigue and recovery
Authors: Cheng Arthur J. , Yamada Takashi , Rassier Dilson E. , Andersson Daniel C. , Westerblad Håkan , Lanner Johanna T.
Published: February 2016

The production of reactive oxygen/nitrogen species (ROS/RNS) is generally considered to increase during physical exercise. Nevertheless, direct measurements of ROS/RNS often show modest increases in ROS/RNS in muscle fibres even during intensive fatiguing stimulation, and the major source(s) of ROS/RNS during exercise is still being debated. In rested muscle fibres, mild and acute exposure to exogenous ROS/RNS generally increases myofibrillar submaximal force, whereas stronger or prolonged exposure has the opposite effect. Endogenous production of ROS/RNS seems to preferentially decrease submaximal force and positive effects of antioxidants are mainly observed during fatigue induced by submaximal contractions. Fatigued muscle fibres frequently enter a prolonged state of reduced submaximal force, which is caused by a ROS/RNS‐dependent decrease in sarcoplasmic reticulum Ca2+ release and/or myofibrillar Ca2+ sensitivity. Increased ROS/RNS production during exercise can also be beneficial and recent human and animal studies show that antioxidant supplementation can hamper the beneficial effects of endurance training. In conclusion, increased ROS/RNS production have both beneficial and detrimental effects on skeletal muscle function and the outcome depends on a combination of factors: the type of ROS/RNS; the magnitude, duration and location of ROS/RNS production; and the defence systems, including both endogenous and exogenous antioxidants.

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Microenvironmental regulation of oligodendrocyte replacement and remyelination in spinal cord injury
Authors: Alizadeh Arsalan , Karimi‐Abdolrezaee Soheila
Published: February 2016

Myelin is a proteolipid sheath enwrapping axons in the nervous system that facilitates signal transduction along the axons. In the central nervous system (CNS), oligodendrocytes are specialized glial cells responsible for myelin formation and maintenance. Following spinal cord injury (SCI), oligodendroglia cell death and myelin damage (demyelination) cause chronic axonal damage and irreparable loss of sensory and motor functions. Accumulating evidence shows that replacement of damaged oligodendrocytes and renewal of myelin (remyelination) are promising approaches to prevent axonal degeneration and restore function following SCI. Neural precursor cells (NPCs) and oligodendrocyte progenitor cells (OPCs) are two main resident cell populations in the spinal cord with innate capacities to foster endogenous oligodendrocyte replacement and remyelination. However, due to the hostile microenvironment of SCI, the regenerative capacity of these endogenous precursor cells is conspicuously restricted. Activated resident glia, along with infiltrating immune cells, are among the key modulators of secondary injury mechanisms that create a milieu impermissible to oligodendrocyte differentiation and remyelination. Recent studies have uncovered inhibitory roles for astrocyte‐associated molecules such as matrix chondroitin sulfate proteoglycans (CSPGs), and a plethora of pro‐inflammatory cytokines and neurotoxic factors produced by activated microglia/macrophages. The quality of axonal remyelination is additionally challenged by dysregulation of the supportive growth factors required for maturation of new oligodendrocytes and axo‐oligodendrocyte signalling. Careful understanding of factors that modulate the activity of endogenous precursor cells in the injury microenvironment is a key step in developing efficient repair strategies for remyelination and functional recovery following SCI.

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All‐optical control of cardiac excitation: combined high‐resolution optogenetic actuation and optical mapping
Authors: Entcheva Emilia , Bub Gil
Published: February 2016

Cardiac tissue is an excitable system that can support complex spatiotemporal dynamics, including instabilities (arrhythmias) with lethal consequences. While over the last two decades optical mapping of excitation (voltage and calcium dynamics) has facilitated the detailed characterization of such arrhythmia events, until recently, no precise tools existed to actively interrogate cardiac dynamics in space and time. In this work, we discuss the combined use of new methods for space‐ and time‐resolved optogenetic actuation and simultaneous fast, high resolution optical imaging of cardiac excitation waves. First, the mechanisms, limitations and unique features of optically induced responses in cardiomyocytes are outlined. These include the ability to bidirectionally control the membrane potential using depolarizing and hyperpolarizing opsins; the ability to induce prolonged sustained voltage changes; and the ability to control refractoriness and the shape of the cardiac action potential. At the syncytial tissue level, we discuss optogenetically enabled experimentation on cell–cell coupling, alteration of conduction properties and termination of propagating waves by light. Specific attention is given to space‐ and time‐resolved application of optical stimulation using dynamic light patterns to perturb ongoing activation and to probe electrophysiological properties at desired tissue locations. The combined use of optical methods to perturb and to observe the system can offer new tools for precise feedback control of cardiac electrical activity, not available previously with pharmacological and electrical stimulation. These new experimental tools for all‐optical electrophysiology allow for a level of precise manipulation and quantification of cardiac dynamics comparable in robustness to the computational setting, and can provide new insights into pacemaking, arrhythmogenesis and suppression or cardioversion.

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Properties of an optogenetic model for olfactory stimulation
Authors: Genovese Federica , Thews Marion , Möhrlen Frank , Frings Stephan
Published: February 2016

Key points

In olfactory research it is difficult to deliver stimuli with defined intensity and duration to olfactory sensory neurons.

Expression of channelrhodopsin 2 (ChR2) in olfactory sensory neurons provides a means to activate these neurons with light flashes. Appropriate mouse models are available.

The present study explores the suitability of an established olfactory marker protein (OMP)/ChR2–yellow fluorescent protein (YFP) mouse model for ex vivo experimentation.

Expression of ChR2 in sensory neurons of the main olfactory epithelium, the septal organ and vomeronasal organ is characterized. Expression pattern of ChR2 in olfactory receptor neurons and the properties of light responses indicate that light stimulation does not impact on signal transduction in the chemosensory cilia.

Light‐induced electro‐olfactograms are characterized with light flashes of different intensities, durations and frequencies.

The impact of light‐induced afferent stimulation on the olfactory bulb is examined with respect to response amplitude, polarity and low‐pass filtering.

For the examination of sensory processing, it is helpful to deliver stimuli in precisely defined temporal and spatial patterns with accurate control of stimulus intensity. This is challenging in experiments with the mammalian olfactory system because airborne odorants have to be transported into the intricate sensory structures of the nose and must dissolve in mucus to be detected by sensory neurons. Defined and reproducible activity can be generated in olfactory sensory neurons that express the light‐gated ion channel channelrhodopsin 2 (ChR2). The neurons can be stimulated by light flashes in a controlled fashion by this optogenetic approach. Here we examined the application of an olfactory marker protein (OMP)/ChR2–yellow fluorescent protein (YFP) model for ex vivo exploration of the olfactory epithelium and the olfactory bulb of the mouse. We studied the expression patterns of ChR2 in the main olfactory system, the vomeronasal system, and the septal organ, and we found that ChR2 is absent from the sensory cilia of olfactory sensory neurons. In the olfactory epithelium, we characterized light‐induced electro‐olfactograms with respect to peripheral encoding of stimulus intensity, stimulus duration and stimulus frequency. In acute slices of the olfactory bulb, we identified specific aspects of the ChR2‐induced input signal, concerning its dynamic range, its low‐pass filter property and its response to prolonged stimulation. Our study describes the performance of the OMP/ChR2–YFP model for ex vivo experimentation on the peripheral olfactory system and documents its versatility and its limitations for olfactory research.
The Impact of Low-Speed Fan Design on Noise: An Exploratory Study
Authors: Moreau Antoine , Guérin Sébastien
Published: February 2016

The steady evolution since the 1950s toward higher bypass ratio engines has enhanced the acoustic role of the fan compared to the jet. This paper addresses the following question: Does a further decrease in fan pressure ratio (FPR) and rotor tip speed provide a significant reduction of fan broadband and tonal noise? The paper presents two conceptual parametric studies conducted with a fast analytical aerodynamic and acoustic prediction tool. The tool includes an aerodynamic fan design model which provides the quantities necessary to assess the tradeoff between efficiency and noise at given thrust conditions. The fan acoustic model has a theoretical formulation for broadband and tonal noise sources which is not based on empirical correlations; it is applied on conventional and contrarotating fan concepts. The first study proposes a variation of the design FPR and evaluates for each concept its impact on noise at three acoustic off-design points. The results obtained, which are in line with a past NASA study, indicate that the optimum pressure ratio in terms of fan noise is well below the fuel-burn optimum. Significant noise reductions of the broadband and tonal interaction components can be achieved with fans operating in a fully subsonic domain. Alternatively, designing at higher speed and pressure ratio near the fuel-burn optimum may invite to consider the contrarotating fan as a candidate: it performs very well in terms of buzz-saw and broadband noise compared to the conventional fan. The second study addresses the variation of design rotor tip speed at constant FPR. Although reduced tip speed may suppress buzz-saw noise, the increased loading related to it implies large blade solidities and wakes which causes a significant increase in broadband noise. Thus, there is an optimum loading that will depend on the severity of fan inflow distortion and on the onset of buzz-saw noise. Here again these conclusions confirm some experimental work performed by NASA on two different fans, and by Rolls-Royce on a third one.
A Continuum Damage Mechanics-Based Viscoplastic Model of Adapted Complexity for High-Temperature Creep–Fatigue Loading
Authors: Wang Weizhe , Buhl Patrick , Klenk Andreas , Liu Yingzheng
Published: February 2016

A continuum damage mechanics (CDM) based viscoplastic constitutive model is established in this study to describe the fully coupling of creep and fatigue behavior. The most significant improvement is the introduction of a continuum damage variable into the constitutive equations, instead of considering creep damage and fatigue damage separately. The CDM-based viscoplastic constitutive material model is implemented using a user-defined subroutine (UMAT). A standard specimen is used for carrying out uniaxial creep, fatigue, and creep–fatigue interaction tests to validate the material model. In addition, to further demonstrate the capability of the material model to predict the complex material behavior, a complex strain-control loading test is performed to validate the material model. The simulated and measured results are in good agreement at different temperatures and loadings, in particular for rapid cyclic softening behavior following crack initiation and propagation.
Contour interpolated radial basis functions with spline boundary correction for fast 3D reconstruction of the human articular cartilage from MR images
Authors: Javaid Zarrar , Boocock Mark G. , McNair Peter J. , Unsworth Charles P.
Published: February 2016

Purpose:

The aim of this work is to demonstrate a new image processing technique that can provide a “near real‐time” 3D reconstruction of the articular cartilage of the human knee from MR images which is user friendly. This would serve as a point‐of‐care 3D visualization tool which would benefit a consultant radiologist in the visualization of the human articular cartilage.

Methods:

The authors introduce a novel fusion of an adaptation of the contour method known as “contour interpolation (CI)” with radial basis functions (RBFs) which they describe as “CI‐RBFs.” The authors also present a spline boundary correction which further enhances volume estimation of the method. A subject cohort consisting of 17 right nonpathological knees (ten female and seven male) is assessed to validate the quality of the proposed method. The authors demonstrate how the CI‐RBF method dramatically reduces the number of data points required for fitting an implicit surface to the entire cartilage, thus, significantly improving the speed of reconstruction over the comparable RBF reconstruction method of Carr. The authors compare the CI‐RBF method volume estimation to a typical commercial package (3d doctor), Carr's RBF method, and a benchmark manual method for the reconstruction of the femoral, tibial, and patellar cartilages.

Results:

The authors demonstrate how the CI‐RBF method significantly reduces the number of data points (p‐value < 0.0001) required for fitting an implicit surface to the cartilage, by 48%, 31%, and 44% for the patellar, tibial, and femoral cartilages, respectively. Thus, significantly improving the speed of reconstruction (p‐value < 0.0001) by 39%, 40%, and 44% for the patellar, tibial, and femoral cartilages over the comparable RBF model of Carr providing a near real‐time reconstruction of 6.49, 8.88, and 9.43 min for the patellar, tibial, and femoral cartilages, respectively. In addition, it is demonstrated how the CI‐RBF method matches the volume estimation of a typical commercial package (3d doctor), Carr's RBF method, and a benchmark manual method for the reconstruction of the femoral, tibial, and patellar cartilages. Furthermore, the performance of the segmentation method used for the extraction of the femoral, tibial, and patellar cartilages is assessed with a Dice similarity coefficient, sensitivity, and specificity measure providing high agreement to manual segmentation.

Conclusions:

The CI‐RBF method provides a fast, accurate, and robust 3D model reconstruction that matches Carr's RBF method, 3d doctor, and a manual benchmark method in accuracy and significantly improves upon Carr's RBF method in data requirement and computational speed. In addition, the visualization tool has been designed to quickly segment MR images requiring only four mouse clicks per MR image slice.
Theoretical substantiation of biological efficacy enhancement for β‐delayed particle decay 9C beam: A Monte Carlo study in combination with analysis with the local effect model approach
Authors: Tian Liheng , Li Qiang , Liu Xinguo , Dai Zhongying , Fu Tingyan , He Pengbo , Yan Yuanlin , Ma Yuanyuan , Huang Qiyan
Published: February 2016

Purpose:

To improve the efficacy of heavy ion therapy, β‐delayed particle decay 9C beam as a double irradiation source for cancer therapy has been proposed. The authors' previous experiment showed that relative biological effectiveness (RBE) values at the depths around the Bragg peak of a 9C beam were enhanced and compared to its stable counterpart 12C beam. The purpose of this study was to explore the nature of the biological efficacy enhancement theoretically.

Methods:

A Monte Carlo simulation study was conducted in this study. First a simplified cell model was established so as to form a tumor tissue. Subsequently, the tumor tissue was imported into the Monte Carlo simulation software package gate and then the tumor cells were virtually irradiated with comparable 9C and 12C beams, respectively, in the simulations. The transportation and particle deposition data of the 9C and 12C beams, derived from the gate simulations, were analyzed with the authors' local effect model implementation so as to deduce cell survival fractions.

Results:

The particles emitted from the decay process of deposited 9C particles around a cell nucleus increased the dose delivered to the nucleus and elicited clustered damages around the secondary particles' trajectories. Therefore, compared to the 12C beam, the RBE value of the 9C beam increased at the depths around their Bragg peaks.

Conclusions:

Collectively, the increased local doses and clustered damages due to the decayed particles emitted from deposited 9C particles led to the RBE enhancement in contrast with the 12C beam. Thus, the enhanced RBE effect of a 9C beam for a simplified tumor model was shown theoretically in this study.
Distortion product otoacoustic emission generation mechanisms and their dependence on stimulus level and primary frequency ratio
Authors: Botti Teresa , Sisto Renata , Sanjust Filippo , Moleti Arturo , D'Amato Luisa
Published: February 2016

In this study, a systematic analysis of the dependence on stimulus level and primary frequency ratio r of the different components of human distortion product otoacoustic emissions has been performed, to check the validity of theoretical models of their generation, as regards the localization of the sources and the relative weight of distortion and reflection generation mechanisms. 2f1 – f2 and 2f2 – f1 distortion product otoacoustic emissions of 12 normal hearing ears from six human subjects have been measured at four different levels, in the range [35, 65] dB sound pressure level, at eight different ratios, in the range [1.1, 1.45]. Time-frequency filtering was used to separate distortion and reflection components. Numerical simulations have also been performed using an active nonlinear cochlear model. Both in the experiment and in the simulations, the behavior of the 2f1 – f2 distortion and reflection components was in agreement with previous measurements and with the predictions of the two-source model. The 2f2 – f1 response showed a rotating-phase component only, whose behavior was in general agreement with that predicted for a component generated and reflected within a region basal to the characteristic place of frequency 2f2 – f1, although alternative interpretations, which are also discussed, cannot be ruled out.
Cues for auditory stream segregation of birdsong in budgerigars and zebra finches: Effects of location, timing, amplitude, and frequency
Authors: Dent Micheal L. , Martin Amanda K. , Flaherty Mary M. , Neilans Erikson G.
Published: February 2016

Deciphering the auditory scene is a problem faced by many organisms. However, when faced with numerous overlapping sounds from multiple locations, listeners are still able to attribute the individual sound objects to their individual sound-producing sources. Here, the characteristics of sounds important for integrating versus segregating in birds were determined. Budgerigars and zebra finches were trained using operant conditioning procedures on an identification task to peck one key when they heard a whole zebra finch song and to peck another when they heard a zebra finch song missing a middle syllable. Once the birds were trained to a criterion performance level on those stimuli, probe trials were introduced on a small proportion of trials. The probe songs contained modifications of the incomplete training song's missing syllable. When the bird responded as if the probe was a whole song, it suggests they streamed together the altered syllable and the rest of the song. When the bird responded as if the probe was a non-whole song, it suggests they segregated the altered probe from the rest of the song. Results show that some features, such as location and intensity, are more important for segregating than other features, such as timing and frequency.
Fitness Field Tests’ Correlation With Game Performance in U-19-Category Basketball Referees
Authors: Nabli Mohamed Ali , Abdelkrim Nidhal Ben , Jabri Imed , Batikh Tahar , Castagna Carlo , Chamari Karim
Published: February 2016

Purpose:

To examine the relation between game performance, physiological responses, and field-test results in Tunisian basketball referees.

Methods:

Computerized time–motion analysis, heart rate (HR), and blood lactate concentration [La–] were measured in 15 referees during 8 competitive games (under-19-y-old Tunisian league). Referees also performed a repeated-sprint test (RSA), Yo-Yo Intermittent Recovery Test level 1 (YYIRTL1), agility T-test, and 30-m sprint with 10-m lap time. Computerized video analysis determined the time spent in 5 locomotor activities (standing, walking, jogging, running, and sprint), then grouped in high-, moderate-, and low-intensity activities (HIAs, MIAs, and LIAs, respectively).

Results:

YYIRTL1 performance correlated with (1) total distance covered during the 4th quarter (r = .52, P = .04) and (2) distance covered in LIA during all game periods (P < .05). Both distance covered and time spent in MIA during the 1st quarter were negatively correlated with the YYIRTL1 performance (r = –.53, P = .035; r = –.67, P = .004, respectively). A negative correlation was found between distance covered at HIA during the 2nd half (3rd quarter + 4th quarter) and fatigue index of the RSA test (r = –.54, P = .029). Mean HR (expressed as %HRpeak) during all game periods was correlated with YYIRTL1 performance (.61 ≤ r < .67, P < .01).

Conclusions:

This study showed that (1) the YYIRTL1 performance is a moderate predictor of game physical performance in U-19 basketball referees and (2) referees’ RSA correlates with the amount of HIA performed during the 2nd half, which represents the ability to keep up with play.
An Incremental Shuttle Wheel Test for Wheelchair Tennis Players
Authors: Groot Sonja de , Valent Linda J. , Fickert Richard , Pluim Babette M. , Houdijk Han
Published: February 2016

Purpose:

To determine the relationship between outcomes of the shuttle wheel test (SWT) and peak oxygen uptake (VO2peak) during that test and whether SWT and VO2peak can discriminate between different skill levels of wheelchair tennis players.

Methods:

Fifteen wheelchair tennis players performed an SWT on a tennis court while VO2 was measured continuously. Outcome measures were VO2peak and achieved stage. Relations between outcomes and Dutch wheelchair tennis ranking were calculated with Spearman correlation. Independent t tests were used to test for differences between national and international players.

Results:

Moderate correlations were found between VO2peak and SWT outcome (r = .40–.47). The tennis ranking correlated weakly with VO2peak (r = –.35) and strongly with SWT outcome (r = –.80). A significant difference was found between national and international players for achieved stage (P = .027) and VO2peak (P = .027).

Conclusions:

The SWT outcome only explained a small part of the variance in VO2peak among players, so it cannot be considered a valid test for aerobic capacity. However, SWT outcomes are related to the skill level of the player and give a good indication of the overall peak wheelchair performance.
Science Signaling
Podcast for 9 February 2016: Transendothelial migration
Authors: Jørgensen Claus , VanHook Annalisa M.
Published: February 2016

Phosphoproteomics analysis identifies signaling events required for transendothelial migration of metastatic cancer cells.