bluuebunny/crossref_metadata_2025 huggingface dataset:
Dissecting Hes-centered transcriptional networks in neural stem cell maintenance and tumorigenesis inDrosophila
Authors: Magadi Srivathsa S. , Voutyraki Chrysanthi , Anagnostopoulos Gerasimos , Zacharioudaki Evanthia , Poutakidou Ioanna K. , Efraimoglou Christina , Stapountzi Margarita , Theodorou Vasiliki , Nikolaou Christoforos , Delidakis Christos
Published: March 2020

Neural stem cells divide during embryogenesis and post embryonic development to generate the entire complement of neurons and glia in the nervous system of vertebrates and invertebrates. Studies of the mechanisms controlling the fine balance between neural stem cells and more differentiated progenitors have shown that in every asymmetric cell division progenitors send a Delta-Notch signal back to their sibling stem cells. Here we show that excessive activation of Notch or overexpression of its direct targets of the Hes family causes stem-cell hyperplasias in theDrosophilalarval central nervous system, which can progress to malignant tumours after allografting to adult hosts. We combined transcriptomic data from these hyperplasias with chromatin occupancy data for Dpn, a Hes transcription factor, to identify genes regulated by Hes factors in this process. We show that the Notch/Hes axis represses a cohort of transcription factor genes. These are excluded from the stem cells and promote early differentiation steps, most likely by preventing the reversion of immature progenitors to a stem-cell fate. Our results suggest that Notch signalling sets up a network of mutually repressing stemness and anti-stemness transcription factors, which include Hes proteins and Zfh1, respectively. This mutual repression ensures robust transition to neuronal and glial differentiation and its perturbation can lead to malignant transformation.
Piglets vocally express the anticipation of (pseudo)-social contexts in their grunts
Authors: Villain A.S. , Hazard A. , Danglot M. , Guérin C. , Boissy A. , Tallet C.
Published: March 2020

Emotions not only arise in reaction to an eliciting event but also while anticipating it, making this context a way to assess the emotional value of events. Anticipatory studies have poorly considered vocalisations whereas they carry information about the emotional state. We studied the grunts of piglets that anticipated two (pseudo)social events known to elicit positive emotions more or less intense: arrival of a familiar conspecifics and arrival of a familiar human. Both time and spectral features of the vocal expression of piglets differed according to the emotional context. Piglets produced low-frequency grunts at a higher rate when anticipating conspecifics compared to human. Spectral noise increased when piglets expected conspecifics, whereas the duration and frequency range increased when expecting a human. When the arrival of conspecifics was delayed grunts duration increased, while when the arrival of the human was delayed spectral parameters were comparable to those during isolation. This shows that vocal expressions in piglets during anticipation are specific to the expected reward and to the time duration between signal and the delivery of the reward. Vocal expression (time and spectral features) is thus a good way to explore emotional state of piglets during anticipation of challenging events.
Infrared absorptions as indicators forPseudomonas aeruginosaandAcinetobacter baumannii
Authors: Yamamoto Masato , Arata Satoru , Fukuchi Kunihiko , Honda Hidehiko , Kobayashi Hirokazu , Inagaki Masahiro
Published: March 2020

There is clinical demand for simple and contact-free diagnosis techniques in medical practice. This study shows that the infrared absorptions of volatile metabolites can be used to distinguish between the air aroundPseudomonas aeruginosa, Acinetobacter baumannii,other bacteria, and normal room air. Gas samples were collected from the air surrounding single and mixed laboratory cultures, and preliminary data on human breath samples are also presented. The infrared spectra of a variety of gasses are measured with a high resolution of 0.5 cm-1to obtain information about the wavenumber position of the key bands. Hence, it is not necessary to specify the molecular species of biomarkers. This work also shows that discrimination rates can be improved by observing additional infrared absorptions caused by different characteristic volatile molecules. The significance of this work is that the specific wavenumber positions of the key bands that allow the application of infrared lasers are provided. As a result, it is considered thatPseudomonas aeruginosaandAcinetobacter baumanniican be monitored more sensitively and easily. With further research and development, this simple approach could be used in future applications to identify infections in healthcare settings.
Numerical response of predators to large variations of grassland vole abundance, long-term community change and prey switches
Authors: Giraudoux Patrick , Levret Aurélien , Afonso Eve , Coeurdassier Michael , Couval Geoffroy
Published: March 2020

Voles can reach high densities with multi-annual population fluctuations of large amplitude, and they are at the base of large and rich communities of predators in temperate and arctic food webs. This status places them at the heart of management conflicts wherein crop protection and health concerns are often raised against conservation issues. Here, a 20-year survey describes the effects of large variations in grassland vole populations on the densities and the daily theoretical food intakes (TFI) of vole predators based on roadside counts. Our results show how the predator community responds to prey variations of large amplitude and how it reorganized with the increase in a dominant predator, here the red fox, which likely negatively impacted hare, European wildcat and domestic cat populations. They also indicate which subset of predator species might have a role in vole population control in the critical phase of a low density of grassland voles. Our study provides empirical support for more timely and better focused actions in wildlife management and vole population control, and it supports an evidence-based and constructive dialogue about management targets and options between all stakeholders of such socio-ecosystems.
Glycoinformatics approach for identifying target positions to inhibit initial binding of SARS-CoV-2 S1 protein to the host cell
Authors: Uslupehlivan Muhammet , Şener Ecem
Published: March 2020

COVID-19 outbreak is still threatening the public health. Therefore, in the middle of the pandemic, all kind of knowledge on SARS-CoV-2 may help us to find the solution. Determining the 3D structures of the proteins involved in host-pathogen interactions are of great importance in the fight against infection. Besides, post-translational modifications of the protein on 3D structure should be revealed in order to understand the protein function since these modifications are responsible for the host-pathogen interaction. Based on these, we predicted O-glycosylation and phosphorylation positions using full amino acid sequence of S1 protein. Candidate positions were further analyzed with enzyme binding activity, solvent accessibility, surface area parameters and the positions determined with high accuracy rate were used to design full 3D glycoprotein structure of the S1 protein using carbohydrate force field. In addition, the interaction between the C-type lectin CD209L and α-mannose residues was examined and carbohydrate recognition positions were predicted. We suggest these positions as a potential target for the inhibition of the initial binding of SARS-CoV-2 S1 protein to the host cell.
Cancer associated talin point mutations disorganise cell adhesion and migration
Authors: Azizi Latifeh , Cowell Alana R. , Mykuliak Vasyl V. , Goult Benjamin T. , Turkki Paula , Hytönen Vesa P.
Published: March 2020

Talin–1 is a key component of the multiprotein adhesion complexes which mediate cell migration, adhesion and integrin signalling and has been linked to cancer in several studies. We analysed talin–1 mutations reported in the COSMIC (Catalogue of Somatic Mutations in Cancer) database and developed a bioinformatics pipeline to predict the severity of each mutation. These predictions were then assessed using biochemistry and cell biology experiments. With this approach we were able to identify several talin–1 mutations affecting integrin activity, actin recruitment and Deleted in Liver Cancer 1 localization. We explored potential changes in talin–1 signalling responses by assessing impact on migration, invasion and proliferation. Altogether, this study describes a pipeline approach of experiments for crude characterization of talin–1 mutants in order to evaluate their functional effects and potential pathogenicity. Our findings suggest that cancer related point mutations in talin–1 can affect cell behaviour and so may contribute to cancer progression.
Direct visualization and characterization of the human zona incerta and surrounding structures
Authors: Lau Jonathan C. , Xiao Yiming , Haast Roy A.M. , Gilmore Greydon , Uludag Kamil , MacDougall Keith W. , Menon Ravi S. , Parrent Andrew G. , Peters Terry M. , Khan Ali R.
Published: March 2020

The zona incerta (ZI) is a small gray matter region of the deep brain first identified in the 19th century, yet direct in vivo visualization and characterization has remained elusive. Noninvasive detection of the ZI and surrounding region could be critical to further our understanding of this widely connected but poorly understood deep brain region and could contribute to the development and optimization of neuromodulatory therapies. We demonstrate that high resolution (submillimetric) longitudinal (T1) relaxometry measurements at high magnetic field strength (7 Tesla) can be used to delineate the ZI from surrounding white matter structures, specifically the fasciculus cerebellothalamicus, fields of Forel (fasciculus lenticularis, fasciculus thalamicus, field H), and medial lemniscus. Using this approach, we successfully derived in vivo estimates of the size, shape, location, and tissue characteristics of substructures in the ZI region, confirming observations only previously possible through histological evaluation that this region is not just a space between structures but contains distinct morphological entities that should be considered separately. Our findings pave the way for increasingly detailed in vivo study and provide a structural foundation for precise functional and neuromodulatory investigation.
Ultraviolet Photodissociation of tryptic peptide backbones at 213 nm
Authors: Kolbowski Lars , Belsom Adam , Rappsilber Juri
Published: March 2020

We analyzed the backbone fragmentation behavior of tryptic peptides of a four protein mixture and ofE. colilysate subjected to Ultraviolet Photodissociation (UVPD) at 213 nm on a commercially available UVPD-equipped tribrid mass spectrometer. We obtained 15,178 high-confidence peptide-spectrum matches by additionally recording a reference beam-type collision-induced dissociation (HCD) spectrum of each precursor. Type a, b and y ions were most prominent in UVPD spectra and median sequence coverage ranged from 5.8% (at 5 ms laser excitation time) to 45.0% (at 100 ms). Overall sequence fragment intensity remained relatively low (median: 0.4% (5 ms) to 16.8% (100 ms) of total intensity) and remaining precursor intensity high. Sequence coverage and sequence fragment intensity ratio correlated with precursor charge density, suggesting that UVPD at 213 nm may suffer from newly formed fragments sticking together due to non-covalent interactions. UVPD fragmentation efficiency therefore might benefit from supplemental activation, as was shown for ETD. Aromatic amino acids, most prominently tryptophan, facilitated UVPD. This points at aromatic tags as possible enhancers of UVPD. Data are available via ProteomeXchange with identifier PXD018176 and onspectrumviewer.org/db/UVPD_213nm_trypPep.
Altered specificity of 15-LOX-1 in the biosynthesis of 7S,14S-diHDHA implicates 15-LOX-2 in biosynthesis of resolvin D5
Authors: Perry Steven C. , Kalyanaraman Chakrapani , Tourdot Benjamin E. , Conrad William S. , Akinkugbe Oluwayomi , Freedman John Cody , Holinstat Michael , Jacobson Matthew P. , Holman Theodore R.
Published: March 2020

The oxylipins, 7S,14S-diHDHA and 7S,17S-diHDHA (RvD5), have been found in macrophages exudates and are believed to function as specialized pro-resolving mediators (SPM’s). Their biosynthesis is thought to proceed through sequential oxidations of docosahexaenoic acid (DHA) by lipoxygenase enzymes, specifically by h5-LOX first to 7S-HDHA, followed by h12-LOX to form 7S,14S-diHDHA or h15-LOX-1 to form 7S,17S-diHDHA (RvD5). In this work, we determined that oxidation of 7S-HpDHA to 7S,14S-diHDHA can be performed by either h12-LOX or h15-LOX-1, with similar kinetics. The oxidation at C14 of DHA by h12-LOX was expected, but the non-canonical reaction of h15-LOX-1 to make primarily 7S,14S-diHDHA was unexpected. Computer modeling suggests the alcohol on C7 of 7S-HDHA hydrogen bonds with the backbone carbonyl of I399, forcing the hydrogen abstraction from C12 to oxygenate on C14, and not C17. This result raised questions regarding synthesis of 7S,17S-diHDHA (RvD5). Strikingly, we find h15-LOX-2 oxygenates 7S-HDHA almost exclusively at C17, forming RvD5 with faster kinetics than h15-LOX-1. The presence of h15-LOX-2 in neutrophils and macrophages, suggests it may have a greater role in biosynthesizing SPM’s than previously thought. We also determined that the reactions of h5-LOX with 14S-HpDHA and 17S-HpDHA are kinetically slow compared to DHA, suggesting these may be minor biosynthetic routesin-vivo. Additionally, we show that 7S,14S-diHDHA and RvD5 have anti-aggregation properties with platelets at low micro-molar potencies, which could directly regulate clot resolution.
Therapeutic genetic variation revealed in diverse Hsp104 homologs
Authors: March Zachary M. , Sweeney Katelyn , Kim Hanna , Yan Xiaohui , Castellano Laura M. , Jackrel Meredith E. , Chuang Edward , Gomes Edward , Michalska Karolina , Jedrzejczak Robert , Joachimiak Andrzej , Caldwell Kim A. , Caldwell Guy A. , Shalem Ophir , Shorter James
Published: March 2020

The AAA+ protein disaggregase, Hsp104, increases fitness under stress by reversing stress-induced protein aggregation. We have engineered potentiated Hsp104 variants to antagonize proteotoxic misfolding linked to human neurodegenerative diseases. However, these Hsp104 variants can exhibit off-target toxicity, which may limit their therapeutic utility. Hsp104 is conserved among all nonmetazoan eukaryotes, which raises the possibility that natural variants might exist with enhanced, selective activity against neurodegenerative disease substrates. To assess this possibility, we screened a cross-kingdom collection of Hsp104 homologs in several yeast proteotoxicity models. We uncovered therapeutic genetic variation among several Hsp104 homologs that specifically antagonize TDP-43 orα-synuclein condensate formation and toxicity in yeast, human cells, andC. elegans. Surprisingly, this variation manifested as increased passive chaperone activity, distinct from disaggregase activity, which neutralizes proteotoxicity of specific substrates. Thus, by exploring natural tuning of passive chaperone activity we elucidated enhanced, substrate-specific agents to counter proteotoxicity underlying neurodegenerative disease.
Regulation of caveolae through cholesterol-depletion dependent tubulation by PACSIN2/Syndapin II
Authors: Amir Aini Gusmira , Takemura Kazuhiro , Hanawa-Suetsugu Kyoko , Oono-Yakura Kayoko , Yasuhara Kazuma , Kitao Akio , Suetsugu Shiro
Published: March 2020

The membrane shaping ability of PACSIN2 via its FCH-BAR (F-BAR) domain has been shown to be essential for caveolar morphogenesis, presumably through the shaping of the caveolar neck. Caveolar membrane contains abundant levels of cholesterol. However, the role of cholesterol in PACSIN2-mediated membrane deformation remains unclear. We show that the binding of PACSIN2 to the membrane could be negatively regulated by the amount of cholesterol in the membrane. We prepared a reconstituted membrane based on the lipid composition of caveolae. The reconstituted membrane with cholesterol had a weaker affinity to the F-BAR domain of PACSIN2 than the membrane without cholesterol, presumably due to a decrease in electrostatic charge density. Consistently, the acute depletion of cholesterol from the plasma membrane resulted in the appearance of PACSIN2-localized tubules with caveolin-1 at their tips, suggesting that the presence of cholesterol inhibited the prominent membrane tubulation by PACSIN2. The tubules induced by PACSIN2 were suggested to be an intermediate of caveolae endocytosis. Consistently, the removal of caveolae from the plasma membrane upon cholesterol depletion was diminished in the cells deficient in PACSIN2. These data suggested that PACSIN2 mediated the caveolae internalization dependently on the amount of cholesterol at the plasma membrane, providing a possible mechanism for the cholesterol-dependent regulation of caveolae.
Differences in post-mating transcriptional responses between conspecific and heterospecific matings inDrosophila
Authors: Ahmed-Braimah Yasir H. , Wolfner Mariana F. , Clark Andrew G.
Published: March 2020

In many animal species, females undergo physiological and behavioral changes after mating. Some of these changes are driven by male-derived seminal fluid proteins, and are critical for fertilization success. Unfortunately, our understanding of the molecular interplay between female and male reproductive proteins remains superficial. Here we analyze the post-mating response in aDrosophilaspecies that has evolved strong gametic incompatibility with its sister species;D. novamexicanafemales produce only 1% fertilized eggs in crosses withD. americanamales, compared to ~98% produced in within-species crosses. This incompatibility is likely caused by mismatched male and female reproductive molecules. In this study we use short-read RNA sequencing to examine the evolutionary dynamics of female reproductive genes and the post-mating transcriptome response in crosses within and between species. First, we found that most female reproductive tract genes are slow-evolving compared to the genome average. Second, post-mating responses in con- and heterospecific matings are largely congruent, but heterospecific mating induces expression of additional stress-response genes. Some of those are immunity genes that are activated by the Imd pathway. We also identify several genes in the JAK/STAT signaling pathway that are induced in heterospecific, but not conspecific mating. While this immune response was most pronounced in the female reproductive tract, we also detect it in the female head and ovaries. Our results show that the female’s post-mating transcriptome-level response is determined in part by the genotype of the male, and that divergence in male reproductive genes and/or traits can have immunogenic effects on females.
FRET-based Tau seeding assay does not represent prion-like templated assembly of Tau fibers
Authors: Kaniyappan Senthilvelrajan , Tepper Katharina , Biernat Jacek , Chandupatla Ram Reddy , Hübschmann Sabrina , Irsen Stephan , Bicher Sandra , Klatt Christoph , Mandelkow Eva-Maria , Mandelkow Eckhard
Published: March 2020

Tau aggregation into amyloid fibers based on the cross-beta structure is a hallmark of several Tauopathies, including Alzheimer Disease (AD). Trans-cellular propagation of Tau with pathological conformation has been suggested as a key disease mechanism. This is thought to cause the spreading of Tau pathology in AD by templated conversion of naive Tau in recipient cells into a pathological state, followed by assembly of pathological Tau fibers, similar to the mechanism proposed for prion pathogenesis. In cell cultures, the process is usually monitored by a FRET assay where the recipient cell expresses the Tau repeat domain (TauRD, with pro-aggregant mutation, e.g., ΔK280 or P301L, ∼13.5 kDa) fused to GFP-based FRET pairs (YFP or CFP, ∼28 kD). Since the diameter of the reporter GFP (∼3 nm) is ∼6.5 times larger than the β-strand distance (0.47nm), this points to a potential steric clash. Hence, we investigated the influence of GFP tagged (N- or C-terminally) TauRDand TauFL(full-length Tau) on their aggregation behavior in vitro. Using biophysical methods (light scattering, atomic force microscopy (AFM), and scanning-transmission electron microscopy (STEM)), we found that the assembly of TauRDΔK-GFP was severely inhibited, even in the presence of nucleation enhancers (heparin and/or pre-formed PHFs from TauRDΔK). Some rare fiber-like particles had a very different subunit packing from proper PHFs, as judged by STEM. The mass per length (MPL) values of TauRDΔKfibrils are equivalent to 4.45 molecules/nm, close to the expected value for a paired-helical fiber with 2 protofilaments and cross-β structure. By contrast, the elongated particles formed by TauRDΔK-GFP have MPL values around ∼2, less than half of the values expected for PHFs, indicating that the subunit packing is distinct. Thus, both kinetic and structural observations are incompatible with a model whereby external Tau can form a template for PHF assembly of Tau-GFP in recipient cells. As a consequence, the observed local increase of FRET in recipient cells must be caused by other signalling processes.
Cryo-EM structure of coronavirus-HKU1 haemagglutinin esterase reveals architectural changes arising from prolonged circulation in humans
Authors: Hurdiss Daniel L. , Drulyte Ieva , Lang Yifei , Shamorkina Tatiana M. , Pronker Matti F. , van Kuppeveld Frank J.M. , Snijder Joost , de Groot Raoul J.
Published: March 2020

The human betacoronaviruses HKU1 and OC43 (subgenusEmbecovirus)arose from separate zoonotic introductions, OC43 relatively recently and HKU1 apparently much longer ago. Embecovirus particles are studded with two types of surface projections called S (for spike) and HE (for haemagglutinin-esterase), with S mediating receptor-binding and membrane fusion and HE acting as a receptor-destroying enzyme. Together, they promote dynamic virion attachment to glycan-based receptors with 9-O-acetylated sialic acid as main constituent. We recently showed that adaptation of HKU1 and OC43 to replication in the human respiratory tract involved loss-of-function mutations in the lectin domain of HE. Here we present the cryo-EM structure of the ∼80 kDa, heavily glycosylated HKU1 HE at a global resolution of 3.4 Å. Comparison to existing HE structures reveals a drastically truncated lectin domain, incompatible with sialic acid binding, but with the structure and function of the HE esterase domain left intact. Our cryo-EM structure, in combination with mass spectrometry analysis, also describes the extent of glycosylation on the now redundant lectin domain, which forms a putative glycan shield. The findings further our insight into the evolution and host adaptation of human embecoviruses and also demonstrate the utility of cryo-EM for studying small, heavily glycosylated proteins which are intractable to X-ray crystallography.
The rRNA m6A methyltransferase METTL5 is involved in pluripotency and developmental programs
Authors: Ignatova Valentina V. , Stolz Paul , Kaiser Steffen , Gustafsson Tobias H. , Lastres Palma Rico , Sanz-Moreno Adrián , Cho Yi-Li , Amarie Oana V. , Aguilar-Pimentel Antonio , Klein-Rodewald Tanja , Calzada-Wack Julia , Becker Lore , Marschall Susan , Kraiger Markus , Garrett Lillian , Seisenberger Claudia , Hölter Sabine M. , Borland Kayla , Van De Logt Erik , Jansen Pascal W.T.C. , Baltissen Marijke P. , Valenta Magdalena , Vermeulen Michiel , Wurst Wolfgang , Gailus-Durner Valerie , Fuchs Helmut , Hrabe de Angelis Martin , Rando Oliver J. , Kellner Stefanie M. , Bultmann Sebastian , Schneider Robert
Published: March 2020

Covalent chemical modifications of cellular RNAs directly impact all biological processes. However, our mechanistic understanding of the enzymes catalyzing these modifications, their substrates and biological functions, remains vague. Amongst RNA modifications N6-methyladenosine (m6A) is widespread and found in messenger (mRNA), ribosomal (rRNA), and noncoding RNAs. Here, we undertook a systematic screen to uncover new RNA methyltransferases. We demonstrate that the methyltransferase-like 5 (METTL5) protein catalyzes m6A in 18S rRNA at position A1832. We report that absence of Mettl5 in mouse embryonic stem cells (mESCs) results in a decrease in global translation rate, spontaneous loss of pluripotency, and compromised differentiation potential. METTL5-deficient mice are born at non-Mendelian rates and develop morphological and behavioral abnormalities. Importantly, mice lacking METTL5 recapitulate symptoms of patients with DNA variants in METTL5, thereby providing a new mouse disease model. Overall, our biochemical, molecular, and in vivo characterization highlights the importance of m6A in rRNA in stemness, differentiation, development, and diseases.
Nexus of knowledge-oriented leadership, knowledge management, innovation and organizational performance in higher education
Authors: Rehman Ubaid Ur , Iqbal Amjad
Published: March 2020

Purpose

The purpose of this research is to investigate the effect of knowledge-oriented leadership on organizational performance of higher education institutions (HEIs) and examine the neglected mediating role of knowledge management (KM) processes and innovation.

Design/methodology/approach

Following the quantitative and cross-sectional research design, data were collected through self-administered questionnaire from 312 faculty members of HEIs of Pakistan. The partial least squares structural equation modelling data analysis technique was applied to test the hypothesized relationships.

Findings

The results indicate that knowledge-oriented leadership has direct and positive effect on organizational performance. Moreover, the findings reveal that KM processes and innovation partially mediate the effect of knowledge-oriented leadership on organizational performance.

Practical implications

This study underscores the imrportant role of knowledge-oriented leadership in HEIs. Findings of this research suggest that by exhibiting knowledge-oriented behaviours, managers of HEIs can effectively manage their knowledge assets, ensure successful implementation of KM processes and augment product and process innovation leading towards superior organizational performance.

Originality/value

This is amongst one of the first studies that proposes an integrated research model and examines interrelationships amongst knowledge-oriented leadership, KM processes, innovation and organizational performance in the context of HEIs.
Analysis of a wind farm with SCIG integrated into a high power system
Authors: Malamov Dian , Hadzhiev Ivan , Zlatanova Vasilina , Terzieva Snejana , Georgiev Aleksandar
Published: March 2020

Purpose

The aim of this paper is a steady-state analysis of the basic electrical characteristics of a wind farm with squirrel-cage induction generators (SCIG), integrated into a high power system. The SCIG are connected to the system by means of a step-up substation 21/115 kV, realized by cable lines.

Design/methodology/approach

The analyses have been done with the help of a computer model, developed in MATLAB/Simulink.

Findings

Results have been obtained, concerning the influence of the SCIG on the active and reactive power, on the power factor and the voltage deviation in the cases of only one generator operating, all generators operating and disabled generators.

Practical implications

The analysis has been carried out for an operating wind farm in the power system. The obtained results are applicable for optimizing and managing the modes of operation of the wind farm.

Originality/value

A mathematical model for studying the electrical parameters of an SCIG integrated into a high power system has been described. A computer model in MATLAB/Simulink has been synthesized. Numerical results have been obtained, concerning the dependence of the active power, the reactive power, the power factor and the voltage deviation on the shaft torque of the wind farms with SCIG.
Employees' experiences of participating in a workplace-supported weight management service: a qualitative inquiry
Authors: Staniford Leanne Jane , Radley Duncan , Gately Paul , Blackshaw Jamie , Thompson Lisa , Coulton Vickie
Published: March 2020

Purpose

The purpose of this study is to explore public health employees' experiences of participating in a commercial weight management programme supported by their employers over a 12-week period.

Design/methodology/approach

Semi-structured interviews were conducted with 28 employees who had participated in the programme (group-based or online).

Findings

The main motivators for enquiring about and attending the programme were: the offer to attend the programme free of charge, the opportunity to kick start their weight loss efforts, to take part in an academic research study and the opportunity for “shared experiences” with their colleagues.

Research limitations/implications

This study did not allow us to explore the reasons why some employees opted not to take up the opportunity for weight management support through their workplace. Further qualitative research with non-engagers would allow us to inquire about why employees might not engage with WM support and offer alternative strategies.

Practical implications

Employers should facilitate their employees' efforts to lead a healthier lifestyle in the long-term creating employer health and safety policies that actively encourage healthy living and weight management. Improving employee health can contribute to increasing productivity, reducing stress and absenteeism.

Originality/value

This paper presents a novel approach to facilitating employees' weight management. Employees perceived their employer-supported participation in a commercial weight management programme outside of their work setting as a positive experience that assisted their weight management efforts suggesting the acceptability and feasibility of this approach to addressing weight in the workplace.
Competition, R&D and innovation in Chilean firms
Authors: Montégu José Pablo , Calvo Carolina , Pertuze Julio A.
Published: March 2020

Purpose

The purpose of this paper is to analyze the effect of competition on both innovation inputs and outputs in Chilean firms. More specifically, the authors investigate whether there is an inverted-U relationship at different stages of the innovation process.

Design/methodology/approach

The sample covers 1,347 firms that responded to both the 4th Chilean Longitudinal Enterprise Survey and the 10th Chilean Innovation Survey. The CDM model (Crépon et al., 1998) is applied to correct for selectivity bias and endogeneity. Competition is proxied by measures of market concentration. The robustness of the results is checked using four alternative indicators.

Findings

The results strongly suggest that competition and both R&D and innovation intensities are linked by an inverted U-shaped curve. The estimated effects of competition on innovation output and labor productivity are rather ambiguous. Thus, market structure would be influencing the firms’ incentives to innovate, but not necessarily their innovation performance.

Research limitations/implications

The model is based on cross-sectional data, hampering the possibility to control for unobserved heterogeneity. Competitive pressures from potential entrants and foreign markets are not captured in the analysis.

Practical implications

Moderate levels of competition would be the optimal market structure in terms of promoting more business R&D and innovation spending.

Originality/value

A previously unutilized data set covering the whole economy is used. Estimations are executed at three different stages of the innovation process. Two types of innovation input and four types of innovation output are taken into account.
Industry perspectives on Malaysian hotel minimum wage issues
Authors: Balasingam Ann Selvaranee , Hussain Kashif , Manaf Alwie
Published: March 2020

Purpose

The purpose of this paper is to investigate and compare the impact of the minimum wage order from the perspectives of two different stakeholders, namely, hotel managers and employees, in the Malaysian hotel industry.

Design/methodology/approach

For the study, qualitative data were collected through semi-structured interviews from three managers and three employees from hotels in West Malaysia.

Findings

From the managers’ perspective, minimum wage implementation has resulted in managers adopting the best payment structure to reduce labour costs for the operators, deciding to reduce the service charge allocation to employees and having to deal with minimal improvement in employee productivity and motivation. In contrast, the positive impact from the managers’ perspective is lower turnover intentions and social justice for foreign workers. From the employees’ perspective, there is a rather negative impact – minimum wage policy has resulted in a minimal increase in the salary. From a positive perspective, employees said that they have experienced an improvement in living standards.

Originality/value

This research presents current responses from hotel participants regarding the latest wage increase impact, some six years after its implementation.
Core–periphery dynamics in a plant–pollinator network
Authors: Miele Vincent , Ramos‐Jiliberto Rodrigo , Vázquez Diego P.
Published: March 2020

Mutualistic networks are highly dynamic, characterized by high temporal turnover of species and interactions. Yet, we have a limited understanding of how the internal structure of these networks and the roles species play in them vary through time.

We used 6 years of observation data and a novel statistical method (dynamic stochastic block models) to assess how network structure and species' structural position within the network change throughout subseasons of the flowering season and across years in a quantitative plant–pollinator network from a dryland ecosystem in Argentina.

Our analyses revealed a core–periphery structure persistent through subseasons and years. Yet, species structural position as core or peripheral was highly dynamic: virtually all species that were at the core in some subseasons were also peripheral in other subseasons, while many other species always remained peripheral.

Our results illuminate our understanding of the dynamics of mutualistic networks and have important implications for ecosystem management and conservation.
Oncogenic pseudogene DUXAP10 knockdown suppresses proliferation and invasion and induces apoptosis of papillary thyroid carcinoma cells by inhibition of Akt/mTOR pathway
Authors: Li Jian , Jiang Li , Liu Zhu , Li Yanguo , Xu Yang , Liu Hongwei
Published: March 2020

Pseudogenes, another novel group of non‐coding segments without protein‐coding capacity, are closely associated with tumourigenesis and cancer progression. Double homeoboxA pseudogene 10 (DUXAP10) is reported to be robustly expressed in thyroid carcinoma. However, the functional role and underlying mechanism of DUXAP10 in papillary thyroid carcinoma (PTC) progression remain undefined. DUXAP10 expression in PTC cells was detected by qRT‐PCR. Cell proliferation and invasion were determined using 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide (MTT) and Transwell invasion assay, respectively. Apoptosis was evaluated using flow cytometry. Protein expression of matrix metalloproteinase (MMP)‐2, MMP‐9, protein kinase B (Akt), phosphorylated Akt, mammalian target of rapamycin (mTOR), and phosphorylated mTOR was examined by western blot. Results showed that DUXAP10 was significantly overexpressed in PTC cells compared with normal thyroid follicular epithelium cells. DUXAP10 silencing suppressed cell proliferation and invasive ability, reduced the expression of MMP‐2 and MMP‐9, and increased apoptotic rate and caspase‐3 activity in PTC cells. Additionally, the Akt/mTOR pathway was inhibited following DUXAP10 knockdown in PTC cells. Activation of the Akt/mTOR pathway by 740Y‐P and MHY1485 attenuated DUXAP10 knockdown‐induced proliferation reduction, invasion suppression and apoptosis in PTC cells. In conclusion, DUXAP10 knockdown suppressed proliferation and invasion and induced apoptosis in PTC cells at least partially by inhibition of the Akt/mTOR pathway.
The JAK2 inhibitor AG490 regulates the Treg/Th17 balance and alleviates DSS‐induced intestinal damage in IBD rats
Authors: Guo Jing , Wang Li‐yun , Wu Jie , Xu Ling‐fen , Sun Mei
Published: March 2020

The pathogenesis of inflammatory bowel disease (IBD) remains unclear, and it is currently believed that an imbalance in regulatory T (Treg) cells/T helper 17 cells (Th17 cells) is related to the occurrence and development of IBD. Recently, the JAK2 inhibitor AG490 has been used in animal models such as rheumatoid arthritis and bronchial asthma models and shown to exert immunoregulatory functions that improve disorder in the Treg/Th17 cell balance. This study aimed to evaluate the effect of AG490 on the intestinal inflammatory process in an IBD rat model. A dextran sulfate sodium (DSS)‐induced IBD rat model was established, and disease activity index (DAI) scores were calculated. The histopathological damage score was determined by haematoxylin‐eosin (H&E) staining. Treg/Th17 cells in the spleen were detected by flow cytometry. The levels of interleukin (IL)‐10, IL‐6 and IL‐17A were detected by enzyme‐linked immunosorbent assay (ELISA). AG490 attenuated DSS‐induced IBD injury by regulating the Treg/Th17 balance and related cytokine secretion to reduce the DAI and colonic tissue damage. Thus, AG490 may be a new method for effective treatment of IBD.
Distinct assembly mechanisms underlie similar biogeographical patterns of rare and abundant bacteria in Tibetan Plateau grassland soils
Authors: Ji Mukan , Kong Weidong , Stegen James , Yue Linyan , Wang Fei , Dong Xiaobin , Cowan Don A , Ferrari Belinda C
Published: March 2020

Rare biosphere represents the majority of Earth's biodiversity and performs vital ecological functions, yet little is known about its biogeographical patterns and community assembly processes in terrestrial ecosystems. Herein, we investigated the community composition and phylogeny of rare (relative abundance <0.1%) and abundant (>1%) bacteria in dryland grassland soils on the Tibetan Plateau. Results revealed similar biogeographical patterns of rare and abundant bacteria at both compositional and phylogenetic levels, but rare subcommunity was more heavily influenced by stochasticity (72%) than the abundant (57%). The compositional variation of rare bacteria was less explained by environmental factors (41%) than that of the abundant (80%), while the phylogeny of rare bacteria (36%) was more explained than that of the abundant (29%). The phylogeny of rare bacteria was equally explained by local factors (soil and vegetation) and geospatial distance (11.5% and 11.9% respectively), while that of the abundant was more explained by geospatial distance (22.1%) than local factors (11.3%). Furthermore, a substantially tighter connection between the community phylogeny and composition was observed in rare (R2 = 0.65) than in abundant bacteria (R2 = 0.08). Our study provides novel insights into the assembly processes and biographical patterns of rare and abundant bacteria in dryland soils.
Anaerobic microbial communities and their potential for bioenergy production in heavily biodegraded petroleum reservoirs
Authors: de Rezende Júlia R. , Oldenburg Thomas B. P. , Korin Tetyana , Richardson William D. L. , Fustic Milovan , Aitken Carolyn M. , Bowler Bernard F. J. , Sherry Angela , Grigoryan Alexander , Voordouw Gerrit , Larter Stephen R. , Head Ian M. , Hubert Casey R. J.
Published: March 2020

Most of the oil in low temperature, non‐uplifted reservoirs is biodegraded due to millions of years of microbial activity, including via methanogenesis from crude oil. To evaluate stimulating additional methanogenesis in already heavily biodegraded oil reservoirs, oil sands samples were amended with nutrients and electron acceptors, but oil sands bitumen was the only organic substrate. Methane production was monitored for over 3000 days. Methanogenesis was observed in duplicate microcosms that were unamended, amended with sulfate or that were initially oxic, however methanogenesis was not observed in nitrate‐amended controls. The highest rate of methane production was 0.15 μmol CH4 g−1 oil d−1, orders of magnitude lower than other reports of methanogenesis from lighter crude oils. Methanogenic Archaea and several potential syntrophic bacterial partners were detected following the incubations. GC–MS and FTICR–MS revealed no significant bitumen alteration for any specific compound or compound class, suggesting that the very slow methanogenesis observed was coupled to bitumen biodegradation in an unspecific manner. After 3000 days, methanogenic communities were amended with benzoate resulting in methanogenesis rates that were 110‐fold greater. This suggests that oil‐to‐methane conversion is limited by the recalcitrant nature of oil sands bitumen, not the microbial communities resident in heavy oil reservoirs.
Omental apoplexy: Unravelling the mystery
Authors: Moriarty Heather K , Martin Katherine , Koukounaras Jim , Goh Gerard S , Clements Warren
Published: March 2020

Introduction

To describe cases omental haemorrhage and to review the literature on this topic.

Methods

We describe three cases of spontaneous omental haemorrhage and discuss various management strategies, in an attempt to provide direction for similar cases in the future.

Results

A number of case reports of spontaneous or idiopathic omental haemorrhage exist in the literature. These cases are often attributed to an underlying vasculopathy, such as segmental arterial mediolysis (SAM). Appropriate resuscitation is paramount for best outcome. Severe bleeding may require surgery or transcatheter arterial embolisation, which is best performed early if required. Endovascular management using selective catheterisation of the bleeding vessel and embolisation is a minimally invasive alternative to emergent operative intervention. In the three cases we present, endovascular embolisation was performed in two patients, and surgical ligation in a third. Segmental arterial mediolysis is considered the likely aetiology in at least 2 of the 3 cases, based on imaging findings. No further episodes of haemorrhage occurred at follow‐up (ranging from 6 months to 2 years).

Conclusions

Acute omental haemorrhage is a rare condition; however, it may be associated with significant morbidity and mortality. CT angiography is the imaging of choice. Management strategies include both endovascular and surgical intervention.
Testing the utility of species distribution modelling using Random Forests for a species in decline
Authors: Burns Phoebe A. , Clemann Nick , White Matt
Published: March 2020

Habitat suitability estimates derived from species distribution models (SDMs) are increasingly used to guide management of threatened species. Poorly estimating species’ ranges can lead to underestimation of threatened status, undervaluing of remaining habitat and misdirection of conservation funding. We aimed to evaluate the utility of a SDM, similar to the models used to inform government regulation of habitat in our study region, in estimating the contemporary distribution of a threatened and declining species. We developed a presence‐only SDM for the endangered New Holland Mouse (Pseudomys novaehollandiae) across Victoria, Australia. We conducted extensive camera trap surveys across model‐predicted and expert‐selected areas to generate an independent data set for use in evaluating the model, determining confidence in absence data from non‐detection sites with occupancy and detectability modelling. We assessed the predictive capacity of the model at thresholds based on (1) sum of sensitivity and specificity (SSS), and (2) the lowest presence threshold (LPT; i.e. the lowest non‐zero model‐predicted habitat suitability value at which we detected the species). We detected P. novaehollandiae at 40 of 472 surveyed sites, with strong support for the species’ probable absence from non‐detection sites. Based on our post hoc optimised SSS threshold of the SDM, 25% of our detection sites were falsely predicted as non‐suitable habitat and 75% of sites predicted as suitable habitat did not contain the species at the time of our survey. One occupied site had a model‐predicted suitability value of zero, and at the LPT, 88% of sites predicted as suitable habitat did not contain the species at the time of our survey. Our findings demonstrate that application of generic SDMs in both regulatory and investment contexts should be tempered by considering their limitations and currency. Further, we recommend engaging species experts in the extrapolation and application of SDM outputs.
Effects of brominated and organophosphate ester flame retardants on male reproduction
Authors: Hales Barbara F. , Robaire Bernard
Published: March 2020

Background

Environmental chemicals that interfere with the production and/or action of hormones may have adverse effects on male reproduction. This review focuses on the possible impact of exposure to flame retardant chemicals on male reproduction. Flame retardants are added to a wide variety of combustible materials to prevent fires from starting, slow their spread, and provide time to escape. However, these chemicals are often additive so they leach out into the environment. Governments have restricted the use of polybrominated diphenyl ether flame retardants based on evidence that they are persistent and bioaccumulate and have adverse effects on health. The phasing out of these “legacy” flame retardants has resulted in their replacement with alternatives, such as tetrabromobisphenol A and the organophosphate esters.

Objective

To review the literature on the effects of brominated and organophosphate ester flame retardant chemicals on male reproduction.

Methods

PubMed database was searched for studies reporting the effects of brominated and organophosphate ester flame retardants on male reproduction.

Results

Cell‐based, animal model, and human studies provide evidence that the polybrominated diphenyl ethers act as endocrine‐disrupting chemicals; further, exposure during critical windows of development may be associated with a permanent impact on male reproduction. In vitro and animal model data are accumulating with respect to the effects of tetrabromobisphenol A and organophosphate esters, but few studies have evaluated their impact on human health.

Conclusions

More research on human exposure to replacement flame retardants and the possibility that they may be associated with adverse reproductive health outcomes is a high priority.