bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clostridium difficilealters the structure and metabolism of distinct cecal microbiomes during initial infection to promote sustained colonization
Authors: Jenior Matthew L. , Leslie Jhansi L. , Young Vincent B. , Schloss Patrick D. 
Published: October 2017

AbstractSusceptibility toClostridium difficileinfection is primarily associated with previous exposure to antibiotics, which compromise the structure and function of the gut bacterial community. Specific antibiotic classes correlate more strongly with recurrent or persistentC. difficileinfection. As such, we utilized a mouse model of infection to explore the effect of distinct antibiotic classes on the impact that infection has on community-level transcription and metabolic signatures shortly following pathogen colonization and how those changes may associate with persistence ofC. difficile. Untargeted metabolomic analysis revealed thatC. difficileinfection had significantly larger impacts on the metabolic environment across cefoperazone and streptomycin-pretreated mice, which become persistently colonized compared to clindamycin-pretreated mice where infection quickly became undetectable. Through metagenome-enabled metatranscriptomics we observed that transcripts for genes associated with carbon and energy acquisition were greatly reduced in infected animals, suggesting those niches were instead occupied byC. difficile. Furthermore, the largest changes in transcription were seen in the least abundant species indicating thatC. difficilemay “attack the loser” in gut environments where sustained infection occurs more readily. Overall, our results suggest thatC. difficileis able to restructure the nutrient-niche landscape in the gut to promote persistent infection.
Connexin 43 K63-polyubiquitination on lysines 264 and 303 regulates gap junction internalization
Authors: Kells-Andrews Rachael M. , Margraf Rachel A. , Fisher Charles G. , Falk Matthias M. 
Published: October 2017

ABSTRACTGap junctions (GJs) assembled from connexin (Cx) proteins play a pivotal role in cell-to-cell communication by forming channels that connect the cytosols of adjacent cells. Connexin 43, the best-studied Cx, is ubiquitously expressed in vertebrates. While phosphorylation is known to regulate multiple aspects of GJ function, much less is known about the role ubiquitination plays in these processes. Here we show by using ubiquitination-type specific antibodies and Cx43 lysine (K) to arginine (R) mutants that a portion of Cx43 in GJs can become K63-polyubiquitinated on K264 and K303. Relevant Cx43 K/R mutants assembled significantly larger GJ plaques, exhibited much longer protein half-lives and were internalization impaired. Interestingly, ubiquitin-deficient Cx43 mutants accumulated as hyper-phosphorylated polypeptides in the plasma membrane, suggesting that K63-polyubiquitination may be triggered by phosphorylation. Phospho-specific Cx43 antibodies revealed that upregulated phosphorylation affected serines 368, 279/282, and 255, well-known regulatory PKC and MAPK phosphorylation sites. Together, these novel findings suggest that upon internalization, some Cx43 in GJs becomes K63-polyubiquitinated, ubiquitination is critical for GJ internalization, and that K63-polyubiquitination may be induced by Cx phosphorylation.Summary StatementHere we show that connexin 43 in gap junctions becomes K63-poly ubiquitinated on lysines 264 and 303 and its requirement for gap junction endocytosis. These novel findings significantly contribute to our understanding of GJ turnover and patho-/physiology.Abbreviations usedAGJannular gap junctionAMSHassociated molecule with the SH3 domain of STAMCMEclathrin-mediated endocytosisCxConnexinCx43Connexin 43DUBdeubiquitinaseGJgap junctionMonoUbmonoubiquitinNedd4-1neural precursor cell expressed developmentally down-regulated protein 4-1PMplasma membranePolyUbpolyubiquitinTPA12-O-Tetradecanoylphorbol 13-AcetateTX-100Triton X-100RTroom temperatureUbubiquitin
The civil use of small unmanned aerial systems (sUASs): operational and safety challenges
Authors: Novaro Mascarello Laura , Quagliotti Fulvia 
Published: October 2017

PurposeIn the past decades, both civil and military applications of small unmanned aerial systems (sUASs) have been on the rise. The sUASs guarantee the performance of dangerous, dull, duly and dirty missions, according to the 4D rule. The purpose of this study is to describe, some ethical, operational and safety challenges occur owing to the use of sUASs at over-crowded areas or in emergency scenarios. After an overview of the current sUAS regulations, some strategic configuration elements will be analysed to improve these systems and to define safe and inoffensive sUASs. Nevertheless, some problems have not been completely overcome.Design/methodology/approachThe unmanned vehicles are nowadays applied for different kinds of applications. Search and rescue (S&R) missions; terrain surveillance and monitoring after natural disasters, such as earthquakes and landslides; and transportation of medical equipment and cartography are some examples of the most renowned and important civil missions of sUAS. In all these scenarios, some challenges could be encountered. First, the use of sUASs could compromise the privacy of unaware citizens who are in the area of application. Moreover, even if the unmanned vehicle works according to national and international regulations, there are some hazards both for the ground operators and for the population, because these sUASs could impact the human body after a flight failure.FindingsIn this paper, current principal regulations will be analysed, identifying some differences and discrepancies among them. Moreover, some considerations about the configuration elements are introduced to define the safe use of sUASs. Nevertheless, the privacy challenge is quite complicated to be overcome definitely.Originality/valueConsidering some challenges related to the civil applications of sUASs, new unmanned configurations could be developed to guarantee safety and data protection of unaware people.
Defect detection of bare printed circuit boards based on gradient direction information entropy and uniform local binary patterns
Authors: Li Yunfeng , Li Shengyang 
Published: October 2017

Purpose
The purpose of this paper is to propose a defect detection method of bare printed circuit boards (PCB) with high accuracy.

Design/methodology/approach
First, bilateral filtering of the PCB image was performed in the uniform color space, and the copper-clad areas were segmented according to the color difference among different areas. Then, according to the chaotic characteristics of the spatial distribution and the gradient direction of the edge pixels on the boundary of the defective areas, the feature vector, which evaluates quantitatively the significant degree of the defect characteristics by using the gradient direction information entropy and the uniform local binary patterns, was constructed. Finally, support vector machine classifier was used for the identification and localization of the PCB defects.

Findings
Experimental results show that the proposed algorithm can accurately detect typical defects of the bare PCB, such as short circuit, open circuit, scratches and voids.

Originality/value
Considering the limitations of describing all kinds of defects on bare PCB by using single kind of feature, the gradient direction information entropy and the local binary patterns were fused to build a feature vector, which evaluates quantitatively the significant degree of the defect features.
Breaking the silence of racism injuries: a community-driven study
Authors: Lee Bonnie , Kellett Peter , Seghal Kamal , Van den Berg Corina 
Published: October 2017

Purpose
Injuries resulting from racism are largely hidden by silence. Community services to provide healing from racism are missing in at least one Canadian city. The purpose of this paper is to identify the injuries suffered by immigrants who experienced racism and discuss the development of culturally appropriate programs and tools to address injuries from racism.

Design/methodology/approach
Participants representing visible minorities service providers from non-profit, public-funded organizations in a major Canadian city took part in two focus groups. Data from focus groups were thematically analyzed.

Findings
Racism produces traumatic and persistent psychological, social and intergenerational injuries. An ostensible gap exists in services, professional education and skills to address the psycho-social effects of this complex problem. The complicity of silence in both dominant and subordinated groups contributes to its perpetuation. A dearth of screening and assessment instruments is a barrier in identifying individuals whose mental health and addiction problems may have underlying racism-related etiology. Creation of community healing circles is recommended as a preferred method over individual “treatment” to expose and deconstruct racism, strengthen ethnic identity and intergenerational healing.

Research limitations/implications
These qualitative findings were generated based on the perspectives of a small purposive sample (n=8) of immigrant service providers and immigrants from one Canadian city. Many of these findings are consistent with the existing literature on internalized racism and racism injuries. Generalizability to the wider population of the province and of Canada requires further research.

Practical implications
Practitioners in health and social care as well as educators need to understand the injuries and internalized effects of racism to provide appropriate services and leadership. Development of anti-racism professional knowledge and skills, healing circles, and assessment instruments will contribute to deconstructing racism and mitigating its injuries.

Originality/value
Community-driven studies exploring racism and the lack of services to address the issue are scarce. This study pulls together the experience of service providers and their insights on ways to break the detrimental silence surrounding racism.
Root causes analysis of differential pinion shaft assembly failure in WRX class car
Authors: Królicka Aleksandra , Lesiuk Grzegorz , Katkowski Mikołaj 
Published: October 2017

Purpose
The purpose of this paper is to present a case of fatigue damaging of the attacking roller of the WRC class car. Fatigue fractures are a very essential source of cognitive and usable information about the cause of damage of various engineering components. Microfractography allows extending considerations about the main mechanism of initiation and growth of fatigue cracks. The presented research procedure allowed establishing the root cause analysis of the premature fatigue failure of the pinion shaft.

Design/methodology/approach
The specimen for metallographic investigation was extracted from failures pinion shaft. According to the light microscopy and scanning electron microscopy (SEM) study, the detailed observations of microstructure were performed. Fracture surface of pinion shaft and teeth were examined using SEM. The presence of the extraordinary mechanical notch was found as a potential failure root cause.

Findings
The potential cause of premature failure pinion shaft assembly has been found. The microstructural causes were excluded due to correctly performed heat treatment. The main reason of failure was improper mechanical machining of the pinion shaft due to large mechanical notch.

Originality/value
A detailed metallographic expertise route is presented. The usefulness of fractographic analysis is confirmed in case of the failure analysis of premature pinion shaft. The root cause was found and the concluding remarks are included in this paper.
Role of multiple invasion mechanisms and their interaction in regulating the population dynamics of an exotic tree
Authors: Crandall Raelene M. , Knight Tiffany M. 
Published: October 2017

Abstract

Understanding the mechanisms that allow exotic species to have rapid population growth is an important step in the process of controlling existing invasions and preventing future invasions. Several hypotheses have been proposed to explain why some exotic species become invasive, the most prominent of which focus on the roles of habitat disturbance, competitors and consumers. The magnitude and direction of each of these mechanisms on population dynamics observed in previous studies is quite variable. It is possible that some of this variation results from interactions between mechanisms.

We examined all of these mechanisms and their interactions on the population dynamics of the Asian exotic tree Ailanthus altissima (Simaroubaceae) in fire‐suppressed oak‐hickory forests in Missouri, USA. We experimentally reduced herbivory (using insecticide), reduced interspecific competition (plant removals), and manipulated disturbance with prescribed fire. We projected the effects of these treatments and their interactions on population dynamics by parameterizing an integral projection model.

The lowest population growth rate is found where fire is absent and biotic interactions are present. Fire increased population growth rate, likely through the suppression of interspecific competitors, since competitor removal treatments increased population growth rate in the absence but not presence of fire.

These results indicate that biotic resistance from interspecific competitors, more so than consumers, is important for slowing the invasion of A. altissima. Furthermore, disturbances that weaken biotic interactions, such as fire, should be used with caution when restoring habitats invaded by A. altissima.

Synthesis and applications. Examining the main and interactive effects of disturbance, competition and herbivory on the population dynamics of exotic species provides a comprehensive understanding of the role of these factors in the invasion process and provides guidance for exotic species management.
Canopy‐forming macroalgal beds (Sargassum) on coral reefs are resilient to physical disturbance
Authors: Loffler Zoe , Hoey Andrew S. 
Published: October 2017

Abstract

Disturbances to ecosystems are often considered in terms of their potential to disrupt the feedbacks maintaining a particular ecosystem regime. The likelihood of doing so, however, will be dependent on the nature of the regime and its resilience to disturbance.

Within coral reef ecosystems, shifts from coral‐ to macroalgal dominance are becoming increasingly common and, once established, are difficult to reverse. Most studies to date have focused on the biological removal of macroalgae by herbivores, however, none have considered the resilience of macroalgal beds to physical removal by storms.

We simulated the physical removal of macroalgal biomass from Sargassum beds on an inshore coral reef on Australia's Great Barrier Reef, and monitored recovery for 11 months. Trimming Sargassum biomass but leaving the holdfast intact had no detectable effect on the density, height or biomass of Sargassum compared to adjacent intact, or control, areas after 5 months. In areas where holdfasts were also removed, Sargassum biomass recovered to 50% of control biomass after 11 months.

Given the importance of holdfasts to the resilience of Sargassum beds, we also investigated the ability of herbivores to remove and/or damage holdfasts. Exposing pieces of dead coral with attached Sargassum holdfasts to local herbivore assemblages resulted in a 70% decline in the number of holdfasts over 4 months compared to those protected from herbivores.

Synthesis. Beds of Sargassum are extremely resilient to the physical removal of algal biomass, and as such, storms alone are unlikely to lead to permanent reductions in Sargassum abundance. Persistent reductions in the abundance of macroalgae on degraded coral reefs will not only require the physical or biological removal of algal biomass, but critically, sufficient densities of herbivores capable of removing holdfasts.
Genome‐wide identification of chitin‐binding proteins and characterization of BmCBP1 in the silkworm, Bombyx mori
Authors: Li Zhi‐Lang , Tian Sha , Yang Huan , Zhou Xia , Xu Shu‐Ping , Zhang Zi‐Yu , Gong Jing , Hou Yong , Xia Qing‐You 
Published: October 2017

AbstractThe insect cuticle plays important roles in numerous physiological functions to protect the body from invasion of pathogens, physical injury and dehydration. In this report, we conducted a comprehensive genome‐wide search for genes encoding proteins with peritrophin A‐type (ChtBD2) chitin‐binding domain (CBD) in the silkworm, Bombyx mori. One of these genes, which encodes the cuticle protein BmCBP1, was additionally cloned, and its expression and location during the process of development and molting in B. mori were investigated. In total, 46 protein‐coding genes were identified in the silkworm genome, including those encoding 15 cuticle proteins analogous to peritrophins with one CBD (CPAP1s), nine cuticle proteins analogous to peritrophins with three CBD (CPAP3s), 15 peritrophic membrane proteins (PMPs), four chitinases, and three chitin deacetylases, which contained at least one ChtBD2 domain. Microarray analysis indicated that CPAP‐encoding genes were widely expressed in various tissues, whereas PMP genes were highly expressed in the midgut. Quantitative polymerase chain reaction and western blotting showed that the cuticle protein BmCBP1 was highly expressed in the epidermis and head, particularly during molting and metamorphosis. An immunofluorescence study revealed that chitin co‐localized with BmCBP1 at the epidermal surface during molting. Additionally, BmCBP1 was notably up‐regulated by 20‐hydroxyecdysone treatment. These results provide a genome‐level view of the chitin‐binding protein in silkworm and suggest that BmCBP1 participates in the formation of the new cuticle during molting.
Modeling Associations Between Latent Event Processes Governing Time Series of Pulsing Hormones
Authors: Liu Huayu , Carlson Nichole E. , Grunwald Gary K. , Polotsky Alex J. 
Published: October 2017

Summary
This work is motivated by a desire to quantify relationships between two time series of pulsing hormone concentrations. The locations of pulses are not directly observed and may be considered latent event processes. The latent event processes of pulsing hormones are often associated. It is this joint relationship we model. Current approaches to jointly modeling pulsing hormone data generally assume that a pulse in one hormone is coupled with a pulse in another hormone (one-to-one association). However, pulse coupling is often imperfect. Existing joint models are not flexible enough for imperfect systems. In this article, we develop a more flexible class of pulse association models that incorporate parameters quantifying imperfect pulse associations. We propose a novel use of the Cox process model as a model of how pulse events co-occur in time. We embed the Cox process model into a hormone concentration model. Hormone concentration is the observed data. Spatial birth and death Markov chain Monte Carlo is used for estimation. Simulations show the joint model works well for quantifying both perfect and imperfect associations and offers estimation improvements over single hormone analyses. We apply this model to luteinizing hormone (LH) and follicle stimulating hormone (FSH), two reproductive hormones. Use of our joint model results in an ability to investigate novel hypotheses regarding associations between LH and FSH secretion in obese and non-obese women.
Statistical Inference in A Growth Curve Quantile Regression Model for Longitudinal Data
Authors: Cho Hyunkeun Ryan 
Published: October 2017

Summary
This article describes a polynomial growth curve quantile regression model that provides a comprehensive assessment about the treatment effects on the changes of the distribution of outcomes over time. The proposed model has the flexibility, as it allows the degree of a polynomial to vary across quantiles. A high degree polynomial model fits the data adequately, yet it is not desirable due to the complexity of the model. We propose the model selection criterion based on an empirical loglikelihood that consistently identifies the optimal degree of a polynomial at each quantile. After the parsimonious model is fitted to the data, the hypothesis test is further developed to evaluate the treatment effects by comparing the growth curves. It is shown that the proposed empirical loglikelihood ratio test statistic follows a chi-square distribution asymptotically under the null hypothesis. Various simulation studies confirm that the proposed test successfully detects the difference between the curves across quantiles. When the empirical loglikelihood is employed, we incorporate the within-subject correlation commonly existing in longitudinal data and gain estimation efficiency of the quantile regression parameters in the growth curve model. The proposed process is illustrated through the analysis of randomized controlled longitudinal depression data.
Approximations to the distribution of a test statistic in covariance structure analysis: A comprehensive study
Authors: Wu Hao 
Published: October 2017

In structural equation modelling (SEM), a robust adjustment to the test statistic or to its reference distribution is needed when its null distribution deviates from a χ2distribution, which usually arises when data do not follow a multivariate normal distribution. Unfortunately, existing studies on this issue typically focus on only a few methods and neglect the majority of alternative methods in statistics. Existing simulation studies typically consider only non‐normal distributions of data that either satisfy asymptotic robustness or lead to an asymptotic scaled χ2distribution. In this work we conduct a comprehensive study that involves both typical methods in SEM and less well‐known methods from the statistics literature. We also propose the use of several novel non‐normal data distributions that are qualitatively different from the non‐normal distributions widely used in existing studies. We found that several under‐studied methods give the best performance under specific conditions, but the Satorra–Bentler method remains the most viable method for most situations.
Minimally invasive treatment of complicated parapneumonic effusions and empyemas in adults
Authors: Porcel José M. 
Published: October 2017

AbstractObjectivesTo summarize the evidence underlying the non‐surgical management of patients with complicated parapneumonic effusions (CPPE) or empyemas.Data sourceAll articles published in PubMed according to their relevance with the subject were identified.Results and conclusionsThere is a lack of powered randomized controlled studies comparing medical and surgical approaches to CPPE/empyemas in adults. In addition to antibiotics for an unspecified period of time, CPPE/empyemas can initially be treated with a therapeutic thoracentesis (which can be repeated if necessary), the insertion of a small‐bore chest catheter under ultrasound guidance, or the administration through the catheter of fibrinolytics alone, saline alone or fibrinolytics in combination with either saline or deoxyribonuclease. These conservative measures resolve more than 90% of the cases, thus making a rescue surgery unnecessary.