bluuebunny/crossref_metadata_2025 huggingface dataset:
New Methods to Study the Microcirculation
Authors: Rizzoni Damiano , Agabiti Rosei Claudia , De Ciuceis Carolina , Semeraro Francesco , Rizzoni Marco , Docchio Franco
Published: December 2017

Essential hypertension is associated with structural alterations in the microvessels; in particular, an increase in the media thickness to internal lumen ratio of small resistance arteries (MLR) and a reduction in capillary density have been observed. The evaluation of the morphological characteristics of small resistance arteries in humans is challenging. The gold-standard method is generally considered to be the measurement by wire or pressure micromyography of MLR of subcutaneous small vessels obtained by local biopsies. However, noninvasive techniques for the evaluation of retinal arterioles were recently proposed; in particular, 2 approaches, scanning laser Doppler flowmetry (SLDF) and adaptive optics (AO), seem to provide useful information. Both of them provide an estimation of the wall to lumen ratio (WLR) of retinal arterioles. Moreover, a noninvasive measurement of basal and total capillary density may be obtained by videomicroscopy/capillaroscopy. It has been recently demonstrated that AO has a substantial advantage over SLDF in terms of evaluation of microvascular morphology, since WLR measured with AO is more closely correlated with the M/L of subcutaneous small arteries. The possibility to noninvasively assess in a reliable way, microvascular morphology in a clinical setting may represent a major advancement, since micromyography has substantial limitations in its application due to the local invasiveness of the procedure.
PEITH(Θ): perfecting experiments with information theory in Python with GPU support
Authors: Dony Leander , Mackerodt Jonas , Ward Scott , Filippi Sarah , Stumpf Michael P H , Liepe Juliane
Published: December 2017

Motivation

Different experiments provide differing levels of information about a biological system. This makes it difficult, a priori, to select one of them beyond mere speculation and/or belief, especially when resources are limited. With the increasing diversity of experimental approaches and general advances in quantitative systems biology, methods that inform us about the information content that a given experiment carries about the question we want to answer, become crucial.

Results

PEITH(Θ) is a general purpose, Python framework for experimental design in systems biology. PEITH(Θ) uses Bayesian inference and information theory in order to derive which experiments are most informative in order to estimate all model parameters and/or perform model predictions.

Availability and implementation

https://github.com/MichaelPHStumpf/Peitho
Materials characterization of innovative composite materials for solar-driven thermochemical heat storage (THS) suitable for building application
Authors: Jarimi Hasila , Devrim Aydin , Zhang Yanan , Ding Yate , Ramadan Omar , Chen Xiangjie , Dodo Auwal , Utlu Zafer , Riffat Saffa
Published: December 2017

Thermochemical Heat Storage (THS) systems have recently attracted a lot of attention in research and development. One of the main parameters that influence the performance of a THS system is the thermochemical materials. This paper aims to investigate thermochemical materials which are suitable for both short-term and long-term building heat storage application driven by solar energy for an open system. Innovative composite materials using MgCl2-MgSO4, CaCl2-LiCl and MgSO4- CaCl2 salts mixtures impregnated into vermiculite, and potassium formate (KCOOH) impregnated into silica gel will be presented in this study. Initial screening and characterization results of the composite THS materials based on the energy density using differential scanning calorimetry analysis, mass loss against temperature using thermo-gravimetric analysis, and moisture vapor adsorption isotherms testing are discussed. The characterization analysis suggest that the vermiculite with salts mixtures are promising candidates for thermochemical heat storage (THS) systems compared to composite materials with individual salts. Meanwhile the potential of KCOOH-silica gel as THS materials may be further investigated in the future. The performance of the materials may be further optimized in the future by changing the concentration ratio of the mixed salts.
Polysaccharide Peptide–Induced Virus Resistance Depends on Ca2+Influx by Increasing the Salicylic Acid Content and Upregulating the Leucine-Rich Repeat Gene inArabidopsis thaliana
Authors: Zhao Lei , Chen Yujia , Yang Wen , Zhang Yuanle , Chen Wenbao , Feng Chaohong , Wang Qaochun , Wu Yunfeng
Published: December 2017

Plant viral diseases cause severe economic losses in agricultural production. The development of biosource-derived antiviral agents provides an alternative strategy to efficiently control plant viral diseases. We previously reported that the exogenous application of polysaccharide peptide (PSP) exerts significant inhibitive effects on Tobacco mosaic virus infection in Nicotiana tabacum. In this study, we studied in additional detail the mechanism by which PSP can induce virus resistance in Arabidopsis thaliana. We found that PSP significantly induced Ca2+influx and increased the accumulation of hydrogen peroxide and salicylic acid (SA) in the A. thaliana cells. A gene with a toll interleukin 1 receptor-nucleotide binding site-leucine-rich repeat domain (LRR) was obtained by RNA sequencing in combination with the screening of the gene-deletion mutants of A. thaliana. The LRR gene was deleted, and the inductive response of A. thaliana to PSP was significantly attenuated after mutation. After the heterologous overexpression of the LRR gene in N. benthamiana, the SA content and PR1 gene expression in N. benthamiana were significantly increased. Through analyses of the LRR gene expression and the ability of A. thaliana to resist Cucumber mosaic virus following the treatments of PSP and PSP + ethyleneglycol-bis (beta-aminoethylether)-N,N’-tetraacetic acid, it was shown that PSP enhanced the virus resistance of A. thaliana by inducing Ca2+influx and subsequently improving expression of the LRR gene, which further increased the SA content.
Plant Virus Epidemiology: Applications and Prospects for Mathematical Modeling and Analysis to Improve Understanding and Disease Control
Authors: Jeger M. J. , Madden L. V. , van den Bosch F.
Published: December 2017

In recent years, mathematical modeling has increasingly been used to complement experimental and observational studies of biological phenomena across different levels of organization. In this article, we consider the contribution of mathematical models developed using a wide range of techniques and uses to the study of plant virus disease epidemics. Our emphasis is on the extent to which models have contributed to answering biological questions and indeed raised questions related to the epidemiology and ecology of plant viruses and the diseases caused. In some cases, models have led to direct applications in disease control, but arguably their impact is better judged through their influence in guiding research direction and improving understanding across the characteristic spatiotemporal scales of plant virus epidemics. We restrict this article to plant virus diseases for reasons of length and to maintain focus even though we recognize that modeling has played a major and perhaps greater part in the epidemiology of other plant pathogen taxa, including vector-borne bacteria and phytoplasmas.
Identifying and Managing Patients with Factitious Wounds
Authors: Amr Amro , Schmitt Constanze , Kuipers Thomas , Schoeller Thomas , Eckhardt-Henn Annegret , Werdin Frank
Published: December 2017

OBJECTIVE:

In the majority of cases, autodestructive behaviors lead to acute or chronic wounds. The identification and management of patients with factitious wounds (FWs) is difficult. This article aims to raise awareness, note specific warning signs, and define constructive treatment strategies for these patients.

DESIGN:

A retrospective study of 12 patients with confirmed FWs was performed. The diagnosis was specified according to the criteria of the American Psychiatric Association. Information regarding wound location, therapy, and healing was also collected and analyzed.

MAIN RESULTS:

In this patient cohort, only 5 of 16 diagnostic criteria appeared to correlate well with the assessment of FWs. In 11 patients, the wound location was obvious, and 11 patients received surgical treatment. In 9 cases, study authors observed a healing tendency under occlusive dressings and complete wound healing in 4 cases. In these 4 cases, a psychiatrist was involved in the therapy.

CONCLUSIONS:

Based on this study, new specific warning signs for FWs include “young age,” “obvious location of the wound,” and “promotion of healing with the use of occlusive dressings.” A fundamental knowledge of the disease is necessary for the successful management of FWs. Early identification, avoidance of invasive procedures, consultation with a psychiatrist, and thorough documentation are of utmost importance.
External Evaluation of Population Pharmacokinetic Models of Infliximab in Patients With Inflammatory Bowel Disease
Authors: Santacana Eugènia , Rodríguez-Alonso Lorena , Padullés Ariadna , Guardiola Jordi , Rodríguez-Moranta Francisco , Serra Katja , Bas Jordi , Morandeira, Biology Francisco , Colom Helena , Padullés Núria
Published: December 2017

Background:

Infliximab (IFX) trough levels vary markedly between patients with inflammatory bowel disease (IBD), which is important for clinical response. The aim of this study was to evaluate the performance of previously developed population pharmacokinetic models in patients with IBD for dose individualization for Crohn disease (CD) and ulcerative colitis in our clinical setting.

Methods:

The authors collected 370 trough levels prospectively from 100 adult patients with IBD who were undergoing IFX treatment between July 2013 and August 2016. The external evaluation included prediction- and simulation-based diagnostics [prediction-corrected visual predictive check, prediction- and variability-corrected visual predictive check, and normalized prediction distribution error tests].

Results:

In prediction-based diagnostics, the authors observed a nonsignificant overall mean relative bias of −6.87% and an acceptable imprecision of 8.45%. Approximately 100% of the prediction error was within ±30%, indicating satisfactory predictability. Simulation-based diagnostics indicated model misspecification; thus, the model may not be appropriate for simulation-based applications.

Conclusions:

While simulation-based diagnostics provided unsatisfactory results, the prediction-based diagnostics demonstrate that the population pharmacokinetic model developed by Fasanmade et al for CD can be used to predict and design individualized IFX dose regimens that meet the individual needs of patients with CD and ulcerative colitis.
Selective Endothelial Removal for Peters Anomaly
Authors: Soh Yu Qiang , Mehta Jodhbir S.
Published: December 2017

Purpose:

Peters anomaly is the most common cause of congenital corneal opacities. Although conservative management is often ineffective except in mild cases, surgical intervention in the form of penetrating keratoplasty is fraught with unpredictability and often has unacceptable postoperative outcomes. As such, there is a need to explore alternative surgical interventions that may possibly improve the postoperative visual prognosis in these patients. In this report, we present a case of type 1 Peters anomaly treated by selective endothelial removal without corneal tissue transplantation.

Methods:

A case report with literature review.

Results:

A 21-month-old child, who presented with unilateral type 1 Peters anomaly, underwent selective endothelial removal without corneal tissue transplantation for the treatment of her condition. The patient demonstrated excellent anatomical and visual recovery after the procedure over a 1-year period. Her visual acuity had improved from 20/960 preoperatively to 20/30 during the latest review. Postoperative recovery was not complicated by the development of any sight-threatening complications, and she has been successfully weaned off all topical and systemic medications.

Conclusions:

Selective endothelial removal can potentially be used to treat cases of type 1 Peters anomaly.
Invasive Haemophilus Influenzae Type B Infections in Children with Cancer in the Era of Infant HIB Immunization Programs (1991–2014)
Authors: McNair Joanne , Smith Alyssa , Bettinger Julie A. , Vaudry Wendy , Tan Ben , Desai Shalini , Halperin Scott A. , Top Karina A.
Published: December 2017

We studied the epidemiology of Haemophilus influenzae type b infections among children with cancer admitted to Canadian pediatric hospitals. From 1991 to 2014, 13 cases among children with cancer were identified through active surveillance. Average age was 6.7 years. Six of 7 cases eligible for infant immunization were age-appropriately immunized (vaccine failures). Children with cancer may benefit from booster Hib immunization.
Early Vaccine-type Pneumococcal Acute Otitis Media Does not Predispose to Subsequent Otitis When Compared With Early Acute Otitis Media Due to Other Bacterial Etiology
Authors: Palmu Arto A. , Lahdenkari Mika
Published: December 2017

Background:

Prevention of acute otitis media (AOM), and especially recurrence and biofilm formation, by pneumococcal conjugate vaccines has been hypothesized to be due to prevention of early episodes triggering the vicious cycle. We tested the specific role of vaccine-type pneumococcal AOM in this hypothesis.

Methods:

In the phase III randomized, double-blind Finnish otitis media Vaccine Trial conducted in 1995–1999, children received pneumococcal conjugate vaccine 7 or hepatitis B vaccine as control at 2, 4, 6, and 12 months of age and were followed for AOM. Myringotomy with middle ear fluid aspiration was performed in AOM, and samples were cultured. We compared control-vaccinated children with confirmed vaccine-type or 6A-AOM with those with AOM due to other confirmed etiology within 2–6 months of age (early AOM) and followed for subsequent AOM from 6–24 months of age.

Results:

Eight hundred thirty-one children were enrolled in the Finnish otitis media control arm. Before 6 months of age, 34 children experienced vaccine-type–AOM, and 40 children experienced AOM of other bacterial etiology. The subsequent AOM incidences were 1.9 (95% CI, 1.5–2.4) and 2.1 (1.7–2.5) in these subgroups, respectively. However, the subsequent incidences were lower if no bacteria were detected at AOM (1.5, 1.2–1.8) or if there was no early AOM (1.1, 1.1–1.2).

Conclusions:

Early vaccine-type AOM was not associated with a higher risk of subsequent AOM compared with AOM due to other confirmed bacterial etiology. These data do not support any specific role of vaccine-type pneumococcus in the hypothesis.
Structural Neuroimaging and Neuropsychologic Signatures in Children With Vertically Acquired HIV
Authors: Paul Robert , Prasitsuebsai Wasana , Jahanshad Neda , Puthanakit Thanyawee , Thompson Paul , Aurpibul Linda , Hansudewechakul Rawiwan , Kosalaraksa Pope , Kanjanavanit Suparat , Ngampiyaskul Chaiwat , Luesomboon Wicharn , Lerdlum Sukalaya , Pothisri Mantana , Visrutaratna Pannee , Valcour Victor , Nir Talia M. , Saremi Arvin , Kerr Stephen , Ananworanich Jintanat
Published: December 2017

Background:

Children with vertically acquired HIV exhibit persistent cognitive impairments, yet the corresponding neuroimaging signature of vertical infection remains unclear.

Methods:

Fifty healthy control children and 51 vertically infected children were included in the study. The HIV-infected group consisted of survivors who had not received antiretroviral therapy at birth. The HIV-infected group averaged 11.4 (2.5) years of age, with a median CD4 count of 683 cells/mm3. Most (71%) of the HIV-infected children were on antiretroviral therapy for a median of 34 months (range: 33–42) with HIV RNA <40 copies/mL in 89% of the sample. The HIV-uninfected group averaged 10.6 (2.6) years of age. Magnetic resonance imaging was acquired to determine volumes of the caudate, putamen, thalamus, pallidum, hippocampus, nucleus accumbens, total white matter, total gray matter and cortical gray matter. Correlational analyses examined the degree of shared variance between brain volumes and both cognitive performances and laboratory markers of disease activity (T cells and plasma viral load).

Results:

HIV-infected children exhibited larger volumes of the caudate, nucleus accumbens, total gray matter and cortical gray matter when compared with the controls. Volumetric differences were predominately evident in children under 12 years of age. HIV-infected children performed worse than controls on most neuropsychologic tests, though neither cognitive performances nor laboratory markers corresponded to brain volumes in the HIV-infected children.

Conclusions:

Outcomes of the present study suggest abnormal brain maturation among HIV-infected pediatric survivors. Longitudinal studies of brain integrity and related resilience factors are needed to determine the impact of neuroimaging abnormalities on psychosocial function in pediatric HIV.
TRO40303 Ameliorates Alcohol-Induced Pancreatitis Through Reduction of Fatty Acid Ethyl Ester–Induced Mitochondrial Injury and Necrotic Cell Death
Authors: Javed Muhammad Ahsan , Wen Li , Awais Muhammad , Latawiec Diane , Huang Wei , Chvanov Michael , Schaller Sophie , Bordet Thierry , Michaud Magali , Pruss Rebecca , Tepikin Alexei , Criddle David , Sutton Robert
Published: December 2017

Objectives

Mitochondrial permeability transition pore inhibition is a promising approach to treat acute pancreatitis (AP). We sought to determine (i) the effects of the mitochondrial permeability transition pore inhibitor 3,5-seco-4-nor-cholestan-5-one oxime-3-ol (TRO40303) on murine and human pancreatic acinar cell (PAC) injury induced by fatty acid ethyl esters (FAEEs) or taurolithocholic acid-3-sulfate and (ii) TRO40303 pharmacokinetics and efficacy in experimental alcoholic AP (FAEE-AP).

Methods

Changes in mitochondrial membrane potential (Δψm), cytosolic Ca2+ ([Ca2+]c), and cell fate were examined in freshly isolated murine or human PACs by confocal microscopy. TRO40303 pharmacokinetics were assessed in cerulein-induced AP and therapeutic efficacy in FAEE-AP induced with palmitoleic acid and ethanol. Severity of AP was assessed by standard biomarkers and blinded histopathology.

Results

TRO40303 prevented loss of Δψm and necrosis induced by 100 μM palmitoleic acid ethyl ester or 500 μM taurolithocholic acid-3-sulfate in murine and human PACs. Pharmacokinetic analysis found TRO40303 accumulated in the pancreas. A single dose of 3 mg/kg TRO40303 significantly reduced serum amylase (P = 0.043), pancreatic trypsin (P = 0.018), and histopathology scores (P = 0.0058) in FAEE-AP.

Conclusions

TRO40303 protects mitochondria and prevents necrotic cell death pathway activation in murine and human PACs, ameliorates the severity of FAEE-AP, and is a candidate drug for human AP.
Mutual Support and Challenges Among Chinese Couples Living With Colorectal Cancer
Authors: Li Qiuping , Lin Yi , Chen Ying , Loke Alice Yuen
Published: December 2017

Background

A diagnosis of cancer and its treatment affect couples as a unit, and they must cope and give each other mutual support as dyads. Few studies have focused explicitly on understanding mutual support among couples coping with colorectal cancer (CRC).

Objective

The aim of this study was to explore the mutual support of couples in their journey of coping together with CRC.

Methods

This is a qualitative descriptive study with purposeful sampling. A total of 11 couples in which 1 partner has been diagnosed with CRC were recruited for in-depth interviews.

Results

Three themes and 8 subthemes emerged from a conventional content analysis. The 3 themes were mutual support and reciprocity, challenges confronted in the provision of support, and experiencing adjustments/outcomes.

Conclusion

The findings of this study provide insights to healthcare professionals on the process by which couples coping with CRC give each other mutual support and the related challenges. This will aid in the development of an intervention program to support such couples, through enhancing their mutual support, overcoming challenges, and improving their adjustment/outcomes.

Implications for Practice

Healthcare professionals need to (1) include the spouse of the cancer patients in their care and provide them with support, (2) encourage the couples to share their concerns with each other, (3) encourage spousal caregivers to take good care of themselves while providing support to their loved ones with CRC, and (4) develop a couple-based intervention program in providing support to couples coping with cancer as dyads.
Ecological, angler and spatial heterogeneity drive social and ecological outcomes in an integrated landscape model of freshwater recreational fisheries
Authors: Matsumura S. , Beardmore B. , Haider W. , Dieckmann U. , Arlinghaus R.
Published: December 2017

Freshwater recreational fisheries constitute complex adaptive social-ecological systems (SES) where mobile anglers link spatially structured ecosystems. We present a general social-ecological model of a spatial recreational fishery for northern pike (Esox lucius) that included an empirically measured mechanistic utility model driving angler behaviors. We studied emergent properties at the macro-scale (e.g., region) as a result of local-scale fish-angler interactions, while systematically examining key heterogeneities (at the angler and ecosystem level) and sources of uncertainty. We offer three key insights. First, the angler population size and the resulting latent reginal angling effort exerts a much greater impact on the overall regional-level overfishing outcome than any residential pattern (urban or rural), while the residential patterns strongly affects the location of local overfishing pockets. Second, simplifying a heterogeneous angler population to a homogenous one representing the preference and behaviours of an average angler risks severely underestimating landscape-level effort and regional overfishing. Third, we did not find that ecologically more productive lakes were more systematically overexploited than lower-productive lakes. We conclude that understanding regional-level outcomes depends on considering four key ingredients: regional angler population size, the angler population composition, the specific residential pattern in place and spatial ecological variation. Simplification of any of these may obscure important dynamics and render the system prone to collapse.
Variable Selection in Heterogeneous Datasets: A Truncated-rank Sparse Linear Mixed Model with Applications to Genome-wide Association Studies
Authors: Wang Haohan , Aragam Bryon , Xing Eric P.
Published: December 2017

A fundamental and important challenge in modern datasets of ever increasing dimensionality is variable selection, which has taken on renewed interest recently due to the growth of biological and medical datasets with complex, non-i.i.d. structures. Naïvely applying classical variable selection methods such as the Lasso to such datasets may lead to a large number of false discoveries. Motivated by genome-wide association studies in genetics, we study the problem of variable selection for datasets arising from multiple subpopulations, when this underlying population structure is unknown to the researcher. We propose a unified framework for sparse variable selection that adaptively corrects for population structure via a low-rank linear mixed model. Most importantly, the proposed method does not require prior knowledge of sample structure in the data and adaptively selects a covariance structure of the correct complexity. Through extensive experiments, we illustrate the effectiveness of this framework over existing methods. Further, we test our method on three different genomic datasets from plants, mice, and human, and discuss the knowledge we discover with our method.
Spatial organization and dynamics of RNase E and ribosomes inCaulobacter crescentus
Authors: Bayas Camille A. , Wang Jiarui , Lee Marissa K. , Schrader Jared M. , Shapiro Lucy , Moerner W.E.
Published: December 2017

We report the dynamic spatial organization ofCaulobacter crescentusRNase E (RNA degradosome) and ribosomal protein L1 (ribosome) using 3D single particle tracking and super-resolution microscopy. RNase E formed clusters along the central axis of the cell, while weak clusters of ribosomal protein L1 were deployed throughout the cytoplasm. These results contrast with RNase E and ribosome distribution inE. coli, where RNase E co-localizes with the cytoplasmic membrane and ribosomes accumulate in polar nucleoid-free zones. For both RNase E and ribosomes inCaulobacter, we observed a decrease in confinement and clustering upon transcription inhibition and subsequent depletion of nascent RNA, suggesting that RNA substrate availability for processing, degradation, and translation facilitates confinement and clustering. Moreover, RNase E cluster positions correlate with the subcellular location of chromosomal loci of two highly transcribed ribosomal RNA genes, suggesting that RNase E’s function in ribosomal RNA processing occurs at the site of rRNA synthesis. Thus, components of the RNA degradosome and ribosome assembly are spatiotemporally organized inCaulobacter, with chromosomal readout serving as the template for this organization.
Fast Intensity Adaptation Enhances the Encoding of Sound inDrosophila
Authors: Clemens Jan , Ozeri-Engelhard Nofar , Murthy Mala
Published: December 2017

To faithfully encode complex stimuli, sensory neurons should correct, via adaptation, for stimulus properties that corrupt pattern recognition. Here, we investigate sound intensity adaptation in theDrosophilaauditory system, which is largely devoted to processing courtship song. Mechanosensory neurons (JONs) in the antenna are sensitive not only to sound-induced antennal vibrations, but also to wind or gravity, which affect the antenna’s mean position. Song pattern recognition therefore requires adaptation to antennal position (stimulus mean) in addition to sound intensity (stimulus variance). We discover fast variance adaptation inDrosophilaJONs, which corrects for background noise over the behaviorally relevant intensity range. We determine where mean and variance adaptation arises and how they interact. A computational model explains our results using a sequence of subtractive and divisive adaptation modules, interleaved by rectification. These results lay the foundation for identifying the molecular and biophysical implementation of adaptation to the statistics of natural sensory stimuli.
Static length changes of cochlear outer hair cells can tune low-frequency hearing
Authors: Ciganović Nikola , Warren Rebecca L. , Keçeli Batu , Jacob Stefan , Fridberger Anders , Reichenbach Tobias
Published: December 2017

The cochlea not only transduces sound-induced vibration into neural spikes, it also amplifies weak sound to boost its detection. Actuators of this active process are sensory outer hair cells in the organ of Corti, whereas the inner hair cells transduce the resulting motion into electric signals that propagate via the auditory nerve to the brain. However, how the outer hair cells modulate the stimulus to the inner hair cells remains unclear. Here, we combine theoretical modeling and experimental measurements near the cochlear apex to study the way in which length changes of the outer hair cells deform the organ of Corti. We develop a geometry-based kinematic model of the apical organ of Corti that reproduces salient, yet counter-intuitive features of the organ’s motion. Our analysis further uncovers a mechanism by which a static length change of the outer hair cells can sensitively tune the signal transmitted to the sensory inner hair cells. When the outer hair cells are in an elongated state, stimulation of inner hair cells is largely inhibited, whereas outer hair cell contraction leads to a substantial enhancement of sound-evoked motion near the hair bundles. This novel mechanism for regulating the sensitivity of the hearing organ applies to the low frequencies that are most important for the perception of speech and music. We suggest that the proposed mechanism might underlie frequency discrimination at low auditory frequencies, as well as our ability to selectively attend auditory signals in noisy surroundings.

Author summary

Outer hair cells are highly specialized force producers inside the inner ear: they can change length when stimulated electrically. However, how exactly this electromotile effect contributes to the astonishing sensitivity and frequency selectivity of the inner ear has remained unclear. Here we show for the first time that static length changes of outer hair cells can sensitively regulate how much of a sound signal is passed on to the inner hair cells that forward the signal to the brain. Our analysis holds for the apical region of the inner ear that is responsible for detecting the low frequencies that matter most in speech and music. This shows a mechanisms for how frequency-selectivity can be achieved at low frequencies. It also opens a path for the efferent neural system to regulate hearing sensitivity.
Deciphering microbial interactions in synthetic human gut microbiome communities
Authors: Venturelli Ophelia S. , Carr Alex C. , Fisher Garth , Hsu Ryan H. , Lau Rebecca , Bowen Benjamin P. , Northen Trent , Arkin Adam P.
Published: December 2017

The human gut microbiota comprises a dynamic ecological system that contributes significantly to human health and disease. The ecological forces that govern community assembly and stability in the gut microbiota remain unresolved. We developed a generalizable model-guided framework to predict higher-order consortia from time-resolved measurements of lower-order assemblages. This method was employed to decipher microbial interactions in a diverse 12-member human gut microbiome synthetic community. We show that microbial growth parameters and pairwise interactions are the major drivers of multi-species community dynamics, as opposed to context-dependent (conditional) interactions. The inferred microbial interaction network as well as a top-down approach to community assembly pinpointed both ecological driver and responsive species that were significantly modulated by microbial inter-relationships. Our model demonstrated that negative pairwise interactions could generate history-dependent responses of initial species proportions on physiological timescales that frequently does not originate from bistability. The model elucidated a topology for robust coexistence in pairwise assemblages consisting of a negative feedback loop that balances disparities in monospecies fitness levels. Bayesian statistical methods were used to evaluate the constraint of model parameters by the experimental data. Measurements of extracellular metabolites illuminated the metabolic capabilities of monospecies and potential molecular basis for competitive and cooperative interactions in the community. However, these data failed to predict influential organisms shaping community assembly. In sum, these methods defined the ecological roles of key species shaping community assembly and illuminated network design principles of microbial communities.
Towards simple kinetic models of functional dynamics for a kinase subfamily
Authors: Sultan Mohammad M. , Kiss Gert , Pande Vijay
Published: December 2017

Kinases are ubiquitous enzymes involved in the regulation of critical cellular pathways and have been implicated in several cancers. Consequently, the kinetics and thermodynamics of prototypical kinases are of interest and have been the subject of numerous experimental studies. In-silico modeling of the conformational ensembles of these enzymes, on the other hand, is lacking due to inherent computational limitations. Recent algorithmic advances combined with homology modeling and parallel simulations allow us to address this computational sampling bottleneck. Here, we present the results of molecular dynamics (MD) studies for seven Src family kinase (SFK) members Fyn, Lyn, Lck, Hck, Fgr, Yes, and Blk. We present a sequence invariant extension to Markov state models (MSMs), which allows us to quantitatively compare the structural ensembles of the seven kinases. Our findings indicate that in the absence of their regulatory partners, SFK members have similar in-silico dynamics with active state populations ranging from 4-40% and activation timescales in the hundreds of microseconds. Furthermore, we observe several potentially druggable intermediate states, including a pocket next to the ATP binding site that could be potentially targeted via a small molecule inhibitors. These results establish the utility of MSMs for studying protein families.
Brazil–Bolivia and a horse trade: a postcolonial case within South America
Authors: Wanderley Sergio , Celano Ana
Published: December 2017

Purpose

The purpose of this paper is to investigate the impact of institutional changes in Bolivia (2005-2016) in the power structures within the headquarters (HQs) of a Brazilian energy multinational corporation (MNC) and its subsidiaries in Bolivia.

Design/methodology/approach

This investigation is informed by a postcolonial South–South perspective. The Brazilian and Bolivian managers were interviewed and drawing techniques were used to unveil hidden power relationships. To achieve the multilayered objective, a Lukesian power framework was integrated into the analysis.

Findings

Traces of a postcolonial relationship between Brazil and Bolivia were found, even though Brazil never colonized Bolivia. The power structure within this MNC’s HQ and subsidiaries reflects a postcolonial relationship: local staff members see the Brazilian MNC as the holder of power of resources, process and meaning. Finally, despite its colonizing role, Brazil is depicted as a savior, not an exploiter. Much to the authors’ surprise, the institutional changes in Bolivia – the nationalization of its oil and gas reserves and the declaration of a plurinational state – have not affected the power relationships within the Brazilian MNC.

Originality/value

The contribution to postcolonial investigations within the international business field was carried out in different ways: a review of EMNC literature was conducted in the study for a South–South postcolonial perspective; empirical data from a case within South America were added; a Lukesian power perspective was integrated into the analysis; and finally, drawing techniques were used to unveil hidden power relations.
Shooting for the moon: an analysis of digital initiatives librarian job advertisements
Authors: Skene Elizabeth
Published: December 2017

Purpose

The purpose of this paper is to review the evolution of technology-oriented university librarian positions and analyze digital initiatives librarian job advertisements to determine the number and type of skills that academic libraries desire.

Design/methodology/approach

Forty-nine job postings between October 2010 and March 2016 were found via the Code4Lib listserv. Information on job title, desired skills and responsibilities and other information was compiled and analyzed.

Findings

Twenty-four skills and responsibilities were identified; the top four were metadata, digital preservation, digital collections and digitization. Other skills and responsibilities are frequently listed by ACRL as emerging trends.

Research limitations/implications

Digital initiatives librarian job postings have risen substantially in the past five years. A total of 24 skills and responsibilities were identified and skills related to the administration of digital collections are the top desired skills of digital initiatives librarians.

Originality/value

Job analysis literature has influenced the design of job descriptions for new roles and the literature offers a “picture of how academic librarianship is developing” (Cox and Corrall, 2013, p. 1528). Library administrators are encourage to design digital initiatives librarian positions strategically, basing the responsibilities on demonstrated needs on their campuses, rather than in response to trends in academic librarianship.
Engineering models for softening and relaxation of Gr. 91 steel in creep-fatigue conditions
Authors: Holmström Stefan , De Haan Frits , Führer Ulrich , Pohja Rami , Janousek Jaromir
Published: December 2017

Purpose

There are a number of different approaches for calculating creep-fatigue (CF) damage for design, such as the French nuclear code RCC-MRx, the American ASME III NH and the British R5 assessment code. To acquire estimates for the CF damage, that are not overly conservative, both the cyclic material softening/hardening and the potential changes in relaxation behavior have to be considered. The data presented here and models are an initial glimpse of the ongoing European FP7 project MATISSE effort to model the softening and relaxation behavior of Grade 91 steel under CF loading. The resulting models are used for calculating the relaxed stress at arbitrary location in the material cyclic softening curve. The initial test results show that softening of the material is not always detrimental. The initial model development and the pre-assessment of the MATISSE data show that the relaxed stress can be robustly predicted with hold time, strain range and the cyclic life fraction as the main input parameters. The paper aims to discuss these issues.

Design/methodology/approach

Engineering models have been developed for predicting cyclic softening and relaxation for Gr. 91 steel at 550 and 600°C.

Findings

A simple engineering model can adequately predict the low cycle fatigue (LCF) and CF softening rates of Gr. 91 steel. Also a simple relaxation model was successfully defined for predicting relaxed stress of both virgin and cyclically softened material.

Research limitations/implications

The data are not yet complete and the models will be updated when the complete set of data in the MATISSE project is available.

Practical implications

The models described can be used for predicting P91 material softening in an arbitrary location (n/Nf0) of the LCF and CF cyclic life. Also the relaxed stress in the softened material can be estimated.

Originality/value

The models are simple in nature but are able to estimate both material softening and relaxation in arbitrary location of the softening curve. This is the first time the Wilshire methodology has been applied on cyclic relaxation data.
Technological unemployment as frictional unemployment
Authors: Fiorelli Federico
Published: December 2017

Purpose

The purpose of this paper is to present some scenarios about a possible future evolution of the labour market in the knowledge economy.

Design/methodology/approach

The author used the literature to describe the historical evolution of the technology unemployment.

Findings

Digital technology does not directly generate unemployment, as the balance between jobs destroyed and created has historically always been positive. Indeed, technological unemployment in such a context can manifest itself in the form of frictional unemployment.

Originality/value

The study enriches the literature on the relationship between digital technologies and unemployment rate.
The pricing strategy for Fuji apple in Shaanxi of Chain under the e-commerce environment
Authors: Zhou Shujun , Sun Bingzhen , Ma Weimin , Chen Xiangtang
Published: December 2017

Purpose

The purpose of this paper is to present a new method and model for determining the optimal decision-making for the pricing strategy to the Fuji apple in Shaanxi of Chain which is representing fresh agricultural products under the e-commerce environment.

Design/methodology/approach

Considering the rapid development of information technology as well as internet that actually motivate the e-commerce, Fuji apple is a distinctive product in China’s Shaanxi; its sales channels have extended to online sales under the wave of e-commerce. Internet trading platforms make it possible to trade online in real time between suppliers and customers who live in different geographical areas. In this paper, the authors study how to price online to maximize the total revenue. The challenge is to optimally price two different qualities of apple. Based on the consumer surplus theory, the authors use the method that builds the function of the relationship between the proportion of consumers purchasing different qualities of products and price.

Findings

This paper presents a generalized model to determine the optimal pricing that maximizes the total revenue of a fruit grower over a finite planning horizon. The authors divided discount into two intervals and discussed the optimal discounting and pricing at both intervals. Then they determined the optimal pricing strategy for Fuji apple in Shaanxi of Chain under the e-commerce environment.

Originality/value

This paper makes up for the lack of existing studies of pricing under the e-commerce environment. A new method and approach to the traditional pricing strategy is established and applied to a management decision-making problem with Chinese characteristics in reality.
Study on an airport gate assignment method based on improved ACO algorithm
Authors: Deng Wu , Sun Meng , Zhao Huimin , Li Bo , Wang Chunxiao
Published: December 2017

Purpose

This study aims to propose a new airport gate assignment method to effectively improve the comprehensive operation capacity and efficiency of hub airport. Gate assignment is one of the most important tasks for airport ground operations, which assigns appropriate airport gates with high efficiency reasonable arrangement.

Design/methodology/approach

In this paper, on the basis of analyzing the characteristics of airport gates and flights, an efficient multi-objective optimization model of airport gate assignment based on the objectives of the most balanced idle time, the shortest walking distances of passengers and the least number of flights at apron is constructed. Then an improved ant colony optimization (ICQACO) algorithm based on the ant colony collaborative strategy and pheromone update strategy is designed to solve the constructed model to fast realize the gate assignment and obtain a rational and effective gate assignment result for all flights in the different period.

Findings

In the designed ICQACO algorithm, the ant colony collaborative strategy is used to avoid the rapid convergence to the local optimal solution, and the pheromone update strategy is used to quickly increase the pheromone amount, eliminate the interference of the poor path and greatly accelerate the convergence speed.

Practical implications

The actual flight data from Guangzhou Baiyun airport of China is selected to verify the feasibility and effectiveness of the constructed multi-objective optimization model and the designed ICQACO algorithm. The experimental results show that the designed ICQACO algorithm can increase the pheromone amount, accelerate the convergence speed and avoid to fall into the local optimal solution. The constructed multi-objective optimization model can effectively improve the comprehensive operation capacity and efficiency. This study is a very meaningful work for airport gate assignment.

Originality/value

An efficient multi-objective optimization model for hub airport gate assignment problem is proposed in this paper. An improved ant colony optimization algorithm based on ant colony collaborative strategy and the pheromone update strategy is deeply studied to speed up the convergence and avoid to fall into the local optimal solution.
Bhagavad Gita and Hindu modes of capitalist accumulation in India
Authors: Nayak Bhabani Shankar
Published: December 2017

Purpose

The paper aims to understand and expand the idea of capitalist accumulation process from social structures of accumulation theory to religious structures of accumulation within the Indian context. It analyses the philosophical tenets of Hindu religious philosophy as outlined in the Bhagavad Gita. It argues that the ideological narratives within the Bhagavad Gita are concomitant with the logic of capitalism.

Design/methodology/approach

The paper draws its methodological lineage to nonlinear historical narrative around the concept and construction of Asiatic modes of production debate. The paper follows discourse analysis to locate how the Hindu religion as outlined in Bhagavad Gita provides philosophical foundation to capitalism in India.

Findings

The Bhagavad Gita (Songs of God) gives social and spiritual legitimacy to a specific form of production and accumulation processes by rationalizing and justifying socio-economic stratification based on eternal inequality. The paper focuses on the interface between cardinal principles of Hindu religion as outlined in the Bhagavad Gita and capitalist modes of social and economic processes in India.

Originality/value

The paper aims to advance a new concept called “Hindu modes of accumulation” by advancing the theoretical understanding of the theological processes in the Hindu religion, which reinforces capitalism and capitalist social relations in India.
Experimental assessment and validation of an oil ferrous wear debris sensors family for wind turbine gearboxes
Authors: Macián Vicente , Tormos Bernardo , Miró Guillermo , Rodes Isaac
Published: December 2017

Purpose

The purpose of this study was to perform a complete experimental assessment of a family of oil ferrous wear debris sensor is performed. The family comprised the original sensor and its re-engineered evolution, which is capable of detecting both amount and size of wear debris particles trapped by the sensor and some predefined oil condition properties.

Design/methodology/approach

In this work, the first step was to perform a design of experiments for the sensor validation. A specially defined test rig was implemented, and different ferrous wear debris was collected. For each sensor, two different tests were performed. The first test was called a “void test”, where quantified amounts of debris were collided with the sensor without oil. The second one was a dynamic test, where the sensor was installed in the test rig and different amounts of wear debris were added at a constant rate. In addition, specific tests related with oil properties detection were studied.

Findings

The results show excellent correlation of the sensor output signal with the amount of wear debris and a satisfactory detection of debris size in all ranges. Also, the dynamic test presented adequate representativeness, and sensors performed well in this scenario.

Practical implications

This paper shows the practical implementation of this type of sensor and the usual detection range and rate of detection for different debris size and quantities.

Originality/value

This work has a great utility for maintenance managers and equipment designers to fully understand the potential of this type of sensor and its suitability for the application required.
Research on Dynamic Performance of Independent Metering Control System
Authors: Zhong Qi , Zhang Bin , Niu Mingjie , Hong Haocen , Yang Huayong
Published: December 2017

Compared with traditional valve control systems, the independent metering valve control system (IMVCS) broke down the mechanical connection of the meter-in and meter-out orifices so that it increased the control degrees of freedom. More importantly, it achieved a more energy-efficient control mode for hydraulic system. This paper studied the dynamic characteristics of IMVCS based on fuzzy PID control algorithm. A controller included power amplifier module, voice coil motor (VCM) drive module, data acquisition module and CAN communication module was designed. A SYS/BIOS based embedded operating system was adopted in this controller for fast response. A host computer program based on CAN bus was developed to monitor status of the IMVCS. A series of experiments of displacement control and pressure control have been carried out, and results showed a good dynamic performance and huge potential of energy-efficient control.