bluuebunny/crossref_metadata_2025 huggingface dataset:
3D reconstruction of genomic regions from sparse interaction data
Authors: Mendieta-Esteban Julen , Di Stefano Marco , Castillo David , Farabella Irene , Marti-Renom Marc A
Published: October 2020

Chromosome Conformation Capture (3C) technologies measure the interaction frequency between pairs of chromatin regions within the nucleus in a cell or a population of cells. Some of these 3C technologies retrieve interactions involving non-contiguous sets of loci, resulting in sparse interaction matrices. One of such 3C technologies is Promoter Capture Hi-C (pcHi-C) that is tailored to probe only interactions involving gene promoters. As such, pcHi-C provides sparse interaction matrices that are suitable to characterise short- and long-range enhancer-promoter interactions. Here, we introduce a new method to reconstruct the chromatin structural (3D) organisation from sparse 3C-based datasets such as pcHi-C. Our method allows for data normalisation, detection of significant interactions, and reconstruction of the full 3D organisation of the genomic region despite of the data sparseness. Specifically, it produces reliable reconstructions, in line with the ones obtained from dense interaction matrices, with as low as the 2-3% of the data from the matrix. Furthermore, the method is sensitive enough to detect cell-type-specific 3D organisational features such as the formation of different networks of active gene communities.
Plant endophytic bacteria: a potential resource pool of electroactive microorganisms
Authors: Ling Lijun , Li Zibin , Yang Caiyun , Feng Shenglai , Zhao Yunhua , Ma Wenxia , Lu Lu
Published: October 2020

Electroactive microorganisms play a significant role in microbial fuel cells (MFCs). These devices, which are based on a wide microbial diversity, can convert a large array of organic matter components into sustainable and renewable energy. At present, electricity-producing microorganisms are mostly isolated from sewage, anaerobic sediments and soil, however, the sources are very limited. For a more comprehensive understanding of the electron transfer mechanism of the electricity-producing microorganisms and the interaction with the environment, it is necessary to obtain a thorough understanding of their resource distribution and discover potential resources. In this study, plant tissues were selected to isolate endophytic bacteria, and the electrochemical activity potential of those bacteria was evaluated by high-throughput screening with a WO3 nanoprobe. Twenty-six strains of endophytic bacteria were isolated from plant tissues belonging to Angelica and Sweet Potato, of which 17 strains from 6 genera had electrochemical activity, including Bacillus sp., Pleomorphomonas sp., Rahnella sp., Shinella sp., Paenibacillus sp. and Staphylococcus sp.. Moreover, the electricity-producing microorganisms in the plant tissue are enriched. Microbial community analysis by high-throughput sequence indicated that Pseudomonas and Clostridioides are the dominant genera of MFC anode inoculated with angelica tissue.Staphylococcus and Lachnoclostridium 5 are the dominant genera in MFC anode inoculated with sweet potato tissue. And the most representative Gram-positive strain Staphylococcus succinus subsp. succinus H6 and plant tissue-inoculated MFC were further analyzed for electrochemical activity. After nearly 1500 h of voltage monitoring and cyclic voltammetry analysis, the results showed that a strain numbered H6 and plant tissue-inoculated MFC had a good electrogenerating activity.

Importance

Some biological characteristics of microorganisms are inextricably linked to their living environment. For plant endophytes, some of their biological characteristics have a profound impact on the host. The discovery of the production of electrobacteria in plants helps us to understand the interaction between microorganisms and plants more deeply. For example, there may be intercellular electron transfer between the internally producing bacteria and nitrogen-fixing bacteria to improve the efficiency of nitrogen fixation. In addition, there may be a connection between the weak electrical signal of the plant and the the endophytic electricity-producing microorganismsThe discovery of electricity-producing bacteria in plants also brings a more comprehensive understanding of the distribution of electricity-producing microbial resources and the mechanism of origin.
Altered glutamine metabolism of cultured fibroblasts predicts severity of cardiac dysfunction in the dilated cardiomyopathy with ataxia syndrome (DCMA), a mitochondrial cardiomyopathy
Authors: King Melissa A. , Heger Katherine , Khan Aneal , Sinasac David , Huttlin Edward L. , Greenway Steven C. , Lewis Ian A.
Published: October 2020

Dilated cardiomyopathy with ataxia (DCMA) syndrome is a rare mitochondrial disorder caused by mutations in the poorly understoodDNAJC19gene. The clinical presentation of DCMA is very diverse with symptoms ranging from mild cardiac dysfunction to intractable heart failure leading to death in early childhood. Although several lines of evidence indicate that DCMA symptoms are linked to mitochondrial function, the molecular underpinnings of this disease are unclear and there is no way to predict which patients are at risk for developing life-threatening symptoms. To address this we developed a metabolic flux assay for assessing the metabolic function of mitochondria in dermal fibroblasts derived from DCMA patients. Using this approach we discovered that fibroblasts from patients with DCMA showed elevated glutamine uptake, increased glutamate and ammonium secretion, and elevated lactate production when compared to controls. Moreover, the magnitude of these metabolic perturbations was closely correlated with patient cardiac dysfunction. This clinical/metabolic correlation was confirmed in a second blinded cohort of DCMA fibroblasts. Moreover, our metabolic flux diagnostic strategy correctly differentiated severe from mild DCMA cases with only one incorrect patient classification (positive predictive value 1.0 and negative predictive value 0.83). These findings suggest that glutamine catabolism is abnormal in DCMA and may serve as an early biomarker for predicting clinical progression.

One Sentence Summary

Alterations in glutamine and lactate metabolism in patient-derived dermal fibroblasts are associated with the severity of cardiomyopathy in DCMA.
Multi-organ impairment in low-risk individuals with long COVID
Authors: Dennis Andrea , Wamil Malgorzata , Kapur Sandeep , Alberts Johann , Badley Andrew D. , Decker Gustav Anton , Rizza Stacey A , Banerjee Rajarshi , Banerjee Amitava
Published: October 2020

Background

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection has disproportionately affected older individuals and those with underlying medical conditions. Research has focused on short-term outcomes in hospital, and single organ involvement. Consequently, impact of long COVID (persistent symptoms three months post-infection) across multiple organs in low-risk individuals is yet to be assessed.

Methods

An ongoing prospective, longitudinal, two-centre, observational study was performed in individuals symptomatic after recovery from acute SARS-CoV-2 infection. Symptoms and organ function (heart, lungs, kidneys, liver, pancreas, spleen) were assessed by standardised questionnaires (EQ-5D-5L, Dyspnoea-12), blood investigations and quantitative magnetic resonance imaging, defining single and multi-organ impairment by consensus definitions.

Findings

Between April and September 2020, 201 individuals (mean age 44 (SD 11.0) years, 70% female, 87% white, 31% healthcare workers) completed assessments following SARS-CoV-2 infection (median 140, IQR 105-160 days after initial symptoms). The prevalence of pre-existing conditions (obesity: 20%, hypertension: 6%; diabetes: 2%; heart disease: 4%) was low, and only 18% of individuals had been hospitalised with COVID-19. Fatigue (98%), muscle aches (88%), breathlessness (87%), and headaches (83%) were the most frequently reported symptoms. Ongoing cardiorespiratory (92%) and gastrointestinal (73%) symptoms were common, and 42% of individuals had ten or more symptoms.

There was evidence of mild organ impairment in heart (32%), lungs (33%), kidneys (12%), liver (10%), pancreas (17%), and spleen (6%). Single (66%) and multi-organ (25%) impairment was observed, and was significantly associated with risk of prior COVID-19 hospitalisation (p<0.05).

Interpretation

In a young, low-risk population with ongoing symptoms, almost 70% of individuals have impairment in one or more organs four months after initial symptoms of SARS-CoV-2 infection. There are implications not only for burden of long COVID but also public health approaches which have assumed low risk in young people with no comorbidities.

Funding

This work was supported by the UK’s National Consortium of Intelligent Medical Imaging through the Industry Strategy Challenge Fund, Innovate UK Grant 104688, and also through the European Union’s Horizon 2020 research and innovation programme under grant agreement No 719445.
Quantum refinement with multiple conformations: application to the P-cluster in nitrogenase
Authors: Cao Lili , Ryde Ulf
Published: October 2020

X-ray crystallography is the main source of atomistic information on the structure of proteins. Normal crystal structures are obtained as a compromise between the X-ray scattering data and a set of empirical restraints that ensure chemically reasonable bond lengths and angles. However, such restraints are not always available or accurate for nonstandard parts of the structure, for example substrates, inhibitors and metal sites. The method of quantum refinement, in which these empirical restraints are replaced by quantum-mechanical (QM) calculations, has previously been suggested for small but interesting parts of the protein. Here, this approach is extended to allow for multiple conformations in the QM region by performing separate QM calculations for each conformation. This approach is shown to work properly and leads to improved structures in terms of electron-density maps and real-space difference density Z-scores. It is also shown that the quality of the structures can be gauged using QM strain energies. The approach, called ComQumX-2QM, is applied to the P-cluster in two different crystal structures of the enzyme nitrogenase, i.e. an Fe8S7Cys6 cluster, used for electron transfer. One structure is at a very high resolution (1.0 Å) and shows a mixture of two different oxidation states, the fully reduced PN state (Fe8
2+, 20%) and the doubly oxidized P2+ state (80%). In the original crystal structure the coordinates differed for only two iron ions, but here it is shown that the two states also show differences in other atoms of up to 0.7 Å. The second structure is at a more modest resolution, 2.1 Å, and was originally suggested to show only the one-electron oxidized state, P1+. Here, it is shown that it is rather a 50/50% mixture of the P1+ and P2+ states and that many of the Fe—Fe and Fe—S distances in the original structure were quite inaccurate (by up to 0.8 Å). This shows that the new ComQumX-2QM approach can be used to sort out what is actually seen in crystal structures with dual conformations and to give locally improved coordinates.
Corrosion inhibition behavior of four benzimidazole derivatives and benzotriazole on copper surface
Authors: Liu Lin , Lu Shuang , Wu Ya Qi , Xie Jin Yin , Xing Jinjuan
Published: October 2020

Purpose

This paper aims to reduce environment pollution caused by benzotriazole. The authors chose one of the best inhibitors from 2-aminobenzimidazole, 2-methylbenzimidazol, 2-mercaptobenzimidazole and benzimidazole in combination with benzotriazole.

Design/methodology/approach

The electrochemical measurement indicated that 2-methylbenzimidazol had the best inhibition behavior. Then, it was mixed with benzotriazole. Techniques such as field emission scanning electron microscopy, atomic force microscopy, Raman spectroscopy and optical contact angle measurements were used.

Findings

The results showed that the inhibition efficiency was up to 99.98%, when the mixture concentration was 20 mmol/L and the molar ratio 1:1.

Originality/value

1-benzotriazole was mixed with 2-methylbenzimidazol for the first time. During the exist of methyl, 2-methylbenzimidazol has the better inhibition; this point was ignored by researchers.

Graphical abstract
Understanding the connection between SMEs’ competitiveness and cash flow generation: an empirical analysis from Hungary
Authors: Markus Gabor , Rideg Andras
Published: October 2020

Purpose

The purpose of this paper is to interconnect the firm level competitive performance (competitiveness) to the financial performance of the firms. The goal is to give evidence on how successful small- and medium-sized enterprises (SMEs) use their financial performance to support their competitive performance.

Design/methodology/approach

Competitiveness is interpreted and measured through the resource-based view theory on a wide range of competitiveness measurements with a sample size of 639 SMEs. Financial data originate from official, publicly accessible governmental archives. All data are from a mid-size Central European country (Hungary). To interconnect competitiveness and financial performance, this paper recognizes two types of cash flow, namely, cash flow to the “past” (dividend and debt service) and cash flow to the “future” (CAPEX and innovation). This paper used ordinary least squares regression and binomial logistic regression to analyze connections.

Findings

Cash flows to the “future” have much stronger effects on competitiveness than cash flows to the “past.” Debt services do not affect competitiveness, whereas dividends, CAPEX and innovation efforts have a significant positive connection to competitiveness, showing that higher cash flow indicates higher competitive performance. If this paper knows how much the firm spends on innovation and dividends, in about the four-fifths of the cases, this paper can predict the level of the competitiveness of the firm without any additional information. The level of these variables gives enough information, the variability of them is not relevant.

Research limitations/implications

The explanatory power of future-oriented cash flow elements is much higher than that of the past-oriented ones, while innovation dominates all models. Firms with higher competitiveness build their returns in their cost structure, and only when the financial position of the firm is stable enough, withdraw the financial resource based on a long-term plan. The results are limited by the fact that using the current sample, detailed and representative (e.g. cross-industrial, spatial, etc.) decomposition is not possible.

Originality/value

Literature is focusing on how SMEs reach success, how SMEs “earn money.” There is no evidence on how SMEs “spend money,” earned during their success.
Time-cost-quality-environmental impact trade-off resource-constrained project scheduling problem with DEA approach
Authors: Banihashemi Sayyid Ali , Khalilzadeh Mohammad
Published: October 2020

Purpose

The purpose of this paper is to evaluate project activities' efficiency in different execution modes for the optimization of time–cost-quality and environmental impacts trade-off problem.

Design/methodology/approach

This paper presents a parallel Data Envelopment Analysis (DEA) method for evaluation of project activities with different execution modes to select the best execution mode and find a trade-off between objectives. Also, according to the nature of the project activities, outputs are categorized into desirable (quality) and undesirable (time, cost and environmental impacts) and analyzed based on the DEA model. In order to rank efficient execution modes, the ideal and anti-ideal virtual units method is used. The proposed model is implemented on a real case of a rural water supply construction project to demonstrate its validity.

Findings

The findings show that the use of the efficient execution mode in each activity leads to an optimal trade-off between the four project objectives (time, cost, quality and environmental impacts).

Practical implications

This study help project managers and practitioners with choosing the most efficient execution modes of project activities taking time–cost-quality-environmental impacts into account.

Originality/value

In this paper, in addition to time and cost optimization of construction projects, quality factors and environmental impacts are considered. Further to the authors' knowledge, there is no method for evaluating project activities' efficiency. The efficiency of different activity modes is also evaluated for the first time to select the most efficient modes. This research can assist project managers with choosing the most appropriate execution modes for the activities to ultimately accomplish the project with the lowest time, cost and environmental impacts along with the highest quality.
Antecedents of innovation implementation: a review of literature with meta-analysis
Authors: Singh Shiwangi , Dhir Sanjay , Gupta Ansh , Das Vellupillai Mukunda , Sharma Anuj
Published: October 2020

Purpose

Assessing the antecedents of innovation implementation holds importance for companies, as previous studies have shown that without proper implementation the innovation is doomed to fail. Over the past few years, research on innovation implementation is growing. However, the evidence on the antecedents of innovation implementation is inconsistent. The purpose of the study is to conduct a review of the literature using meta-analysis to summarize the divergent views present in the literature.

Design/methodology/approach

A meta-analysis technique is adopted for reviewing the literature. The literature search was conducted with selected keywords in different databases and top journals from the ABDC list (A* and A).

Findings

The results of the meta-analysis that summarize evidence from 42 papers, 100 effect sizes and 32,223 organizations show the significance and homogeneous/heterogeneous opinions of the past studies. Results reveal the homogeneity in antecedents such as transformational leadership, business collaboration, employee competency, leader competency, absorptive capacity and business size and heterogeneity in the antecedents such as communication, customer collaboration, internal entrainment, external entrainment, implementation climate and strategic resources.

Research limitations/implications

The results imply that managers attempting to implement innovation in the organizations need to first focus on homogenous antecedents followed by heterogeneous antecedents for successful implementation.

Originality/value

This study advocates research on innovation implementation. It tests the significance, nature of the relationship and summarizes the divergent views on antecedents of innovation implementation in an organization. The results of this study can also be used in the theoretical advancement of management innovation literature.
Entrepreneurial ecosystem for tech start-ups in Bangalore: an exploration of structure and gap
Authors: Mungila Hillemane Bala Subrahmanya
Published: October 2020

Purpose

Bangalore has gained international recognition as a technology start-up hub for its vibrant entrepreneurial ecosystem. Against this backdrop, this paper attempts to explore the structure and gap that exist with respect to the entrepreneurial ecosystem for tech start-ups in Bangalore.

Design/methodology/approach

A Delphi technique based four stage interaction with the experts/stakeholders belonging to different components of the entrepreneurial ecosystem (as identified from the literature) in the context of Bangalore is conducted, to gather primary data. This enabled us to define the structure of entrepreneurial ecosystem and analyse the gap that exists between an ideal ecosystem feasible in the Indian context and that one that prevailed in Bangalore.

Findings

The prevailing entrepreneurial ecosystem for tech start-ups in Bangalore is significantly different (lower) relative to an ideal ecosystem feasible in the Indian economic environment, as prescribed by the Delphi experts, both at the aggregate level and at an individual component level. The step-wise (backward) logistic regression analysis revealed that Bangalore ecosystem is primarily lacking in terms of one of the Triple Helices, namely, role of education and research institutions, and two of the five indispensable components, namely, market maturity and mentorship.

Research limitations/implications

It is essential to strengthen and promote the Triple Helix base and the five indispensable components in an entrepreneurial ecosystem, to accelerate the emergence and growth of tech start-ups.

Practical implications

It brings out the nature of entrepreneurial ecosystem structure and the gap between what can be considered an ideal ecosystem and what prevails in Bangalore currently.

Originality/value

This is a primary data based study, which has value for regional policy makers in strategizing to promote Bangalore ecosystem, and for researchers in undertaking “ecosystem gap analysis”.
Civil service reforms in Hong Kong and Thailand: similar goals, different paths
Authors: Huque Ahmed Shafiqul , Jongruck Patamawadee
Published: October 2020

Purpose

The purpose of this paper is to examine the strategies of civil service reforms in Hong Kong and Thailand. It seeks to identify the drivers of reforms in the two cases and explain the divergence in processes that were intended to achieve similar ends.

Design/methodology/approach

This paper adopts a case study approach along with a thorough review of the literature. It is based on secondary materials, including academic studies, government publications and websites, and media reports. It compares approaches, strategies and outcomes of civil service reforms in Hong Kong and Thailand.

Findings

Civil service reforms in Hong Kong focused on improving management through the implementation of New Public Management (NPM) principles, while governance values were prominent in civil service reforms in Thailand.

Originality/value

This paper compares civil service reforms in two dissimilar Asian cases. It highlights the impact of global trends on traditional bureaucratic organizations and reform strategies, and recognizes the impacts of traditions, culture and capacity on civil service reforms.
Insights and future forward for fashion and textile value chain in Uzbekistan
Authors: Khurana Karan , Ataniyazova Zamira
Published: October 2020

Purpose

Uzbekistan is one of the most prominent cotton producers since the soviet era, but it has struggled to establish a complete value chain. The country’s strategic location and industrial potential have not been harnessed accordingly. This paper aims to critically investigate the barriers in the value chain and propose solutions to the stakeholders in the sector.

Design/methodology/approach

The research involves both primary and secondary research methods. Value chain analysis method has been implemented to ground the theories and results. A systematic literature review was conducted to understand the current position in the world market. Official statistical data was collected from the government bodies to support the reflections of academic literature. Primary data was collected by conducting in-depth semi-structured interviews and questionnaires in 50 local textile companies. Finally, the authors have used their empirical evidences from emerging economies to provide solutions to the sector.

Findings

The value chain suffers a disconnect, as the emphasis has been on exporting cotton. Moreover, companies have a very limited technical know-how of supply chain management and hence no value addition to the raw material. The consumer relies on imports, as there is no significant participation from the Uzbek companies across the fashion segments. This is a major loss of earnings to the country.

Originality/value

Existing academic literature revolves around the cotton and silk industry, but, to the best of the authors’ knowledge, there is no study that unites the value chain and provides solutions to its stakeholders. This paper provides a socio-economic vision to the stakeholders, academia and industry so that the country can harness its potential and become one of the leading apparel producing nations in the future.
Library instruction and information literacy 2019
Authors: Withorn Tessa , Messer Kimmitt Joanna , Caffrey Carolyn , Andora Anthony , Springfield Cristina , Ospina Dana , Clarke Maggie , Martinez George , Castañeda Amalia , Haas Aric , Vermeer Wendolyn
Published: October 2020

Purpose

This paper aims to present recently published resources on library instruction and information literacy, providing an introductory overview and a selected annotated bibliography of publications covering various library types, study populations and research contexts.

Design/methodology/approach

This paper introduces and annotates English-language periodical articles, monographs, dissertations, reports and other materials on library instruction and information literacy published in 2019.

Findings

The paper provides a brief description of all 370 sources and highlights sources that contain unique or significant scholarly contributions.

Originality/value

The information may be used by librarians, researchers and anyone interested as a quick and comprehensive reference to literature on library instruction and information literacy.
Investigation the influence of structure parameters on giant-magnetoimpedance effect measured by non-contact method
Authors: Feng Zhu , Zhi Shaotao , Sun Xuecheng , Yan Lili , Liu Cui , Lei Chong
Published: October 2020

Purpose

This paper aims to investigate the influence of structure parameters on giant-magnetoimpedance (GMI) effect measured by non-contact method.

Design/methodology/approach

The GMI sensor contains a Co-based internal magnetic core fabricated by laser cutting and an external solenoid. The influences of magnetic permeability of magnetic core and structure parameters on GMI effect were calculated in theoretical model. The output impedance, resistance, reactance and GMI ratio were measured by non-contact method using impedance analyzer.

Findings

Enhancing external magnetic field intensity can decrease the magnetic permeability of core, which has vital influences on the magnetic property and the output response of GMI sensor. In addition, increasing the width of magnetic core and the number of solenoid turns can increase the maximum GMI ratio. The maximum GMI ratio is 3,230% with core width of 6 mm and solenoid turns of 200.

Originality/value

Comparing with traditional contact-measured GMI sensor, the maximum GMI ratio and the magnetic field sensitivity are improved and the power consumption is decreased in non-contact measured GMI sensor. GMI sensor measured by non-contact method has a wide range of potential applications in ultra-sensitive magnetic field detection.
Optimization of knowledge transferring costs in designing product portfolio: a fuzzy binary linear programming model
Authors: Dorostkar-Ahmadi Nahid , Shafiei Nikabadi Mohsen , babaie-kafaki Saman
Published: October 2020

Purpose

The success of any organization in a knowledge-based economy depends on effective knowledge transferring and then proper use of the transferred knowledge. As is known, optimizing the knowledge transferring costs in a product portfolio plays an important role in improving productivity, competitive advantage and profitability of any organization. Therefore, this paper aims to determine an optimal product portfolio by minimizing the konlwedge transferring costs.

Design/methodology/approach

Here, a fuzzy binary linear programming model is used to select an optimal product portfolio. The model is capable of considering the knowledge transferring costs while taking into account the human-hours constraints for each product by a fuzzy approach. Using fuzzy ranking functions, a reasonable solution of the model can be achieved by classical or metaheuristic algorithms.

Findings

Numerical experiments indicate that the proposed fuzzy model is practically effective.

Originality/value

The contributions of this work essentially consist of considering knowledge transferring costs in selecting an optimal product portfolio and using the fuzzy data which make the model more realistic.
Stress and coupled electromagnetic-thermal analysis of field excited flux switching machine
Authors: Umair Muhammad , Khan Faisal , Ullah Wasiq
Published: October 2020

Purpose

Field excited flux switching machines (FEFSM) are preferred over induction and synchronous machines due to the confinement of all excitation sources on the stator leaving a robust rotor. This paper aims to perform coupled electromagnetic thermal analysis and stress analysis for single phase FEFSM as, prolonged high-speed operational time with core and copper losses makes it prone to stress and thermal constraints as temperature rise in machine lead to degraded electromagnetic performance whereas the violation of the principle stress limit may result in mechanical deformation of the rotor.

Design/methodology/approach

This paper presents the implementation of coupled electromagnetic-thermal and rotor stress analysis on single-phase FEFSM with non-overlap winding configurations using finite element analysis (FEA) methodology in JMAG V. 18.1. three-dimensional (3D) magnetic loss analysis is performed and extended to 3D thermal analysis to predict temperature distribution on various parts of the machine whereas Stress analysis predicts mechanical stress acting upon edges and faces of the rotor.

Findings

Analysis reveals that temperature distribution and rotor stress on the machine is within acceptable limits. A maximum temperature rise of 37.7°C was noticed at armature and field windings, temperature distribution in stator near pole proximity was 35°C whereas no significant change in rotor temperature was noticed. Furthermore, principal stress at the speed of 3,000 rpm and 30,000 rpm was found out to be 0.0305 MPa 3.045 MPa, respectively.

Research limitations/implications

The designed machine will be optimized for improvement of electromagnetic performance followed by hardware implementation and experimental testing in the future.

Practical implications

The model is developed for axial fan applications.

Originality/value

Thermal analysis is not being implemented on FEFSM for axial fan applications which is an important analysis to ensure the electromagnetic performance of the machine.
Amelioration of freeze thaw damage of concrete with multi-walled carbon nano tubes
Authors: Peerzada Mudasir , Naqash Javed Ahmed
Published: October 2020

Purpose

In cold areas, frost damage is the main factor for diminution of durability and serviceability of structures. Due to incessant freeze thaw regimes, micro cracks spread and deteriorate concrete to point of failure.

Design/methodology/approach

The study aims to evaluate the fresh and hardened properties of concrete after thirty freeze-thaw cycles tailored with carbon nano tubes. For this purpose, samples with 0.4, 0.45, 0.48, 0.5 and 0.55 water cement ratio while 0.5 and 1% carbon nano tube (CNT) content by weight of cement were prepared.

Findings

At 0.48 water cement ratio and 0.5% CNT by weight of cement workability reduced by 37% and water absorption reduced by 0.04%. But compressive strength, split tensile strength and flexural strength increased by 15.38, 33.02 and 15.75%, respectively, after 30 freeze thaw cycles. Also, weight loss reduced with addition of 0.5% CNT by weight of cement after freeze thaw cycles.

Originality/value

Novelty of this research is to tailor traditional concrete with new materials.
Resilience of rhizosphere microbial predators and their prey communities after an extreme heat event
Authors: Thakur Madhav P. , van der Putten Wim H. , Apon Fariha , Angelini Ezio , Vreš Branko , Geisen Stefan
Published: October 2020

Climate change is known to disrupt above‐ground food chains when the various trophic layers respond differently to warming. However, little is known about below‐ground food chains involving microbial preys and their predators. Here, we study how climate warming‐induced heat shocks influence resistance (change immediately after a disturbance) and resilience (ability to recover back to pre‐disturbance levels) in rhizosphere microbial communities.

We used three species of rhizosphere protists as microbial predators and six different rhizosphere bacterial communities as their prey. Protist species and bacterial communities were extracted from Centaurea stoebe—a range‐expanding plant species in the Northern Europe. We then examined the temporal dynamics of protists and bacterial communities after an extreme heat event for several generations with sufficient recovery periods. We hypothesized that bacterial community resistance and resilience after the extreme heat event would be higher particularly when extreme heat effects would negatively affect their predators.

Our results show that prey community biomass was strongly reduced after the extreme heat event and persisted with lower biomass throughout the recovery period. Opposite to what was expected, predators showed negligible changes in their active density after the same heat event. However, abundances of the three predators varied markedly in their temporal dynamics independent of the extreme heat event. Extreme heat event further increased the inactive density of predators, whereas one of the predators showed a decline in its body size owing to extreme heat event. Bacterial community resistance and resilience after the extreme heat event were independent of predator presence, although species‐specific effects of predators on bacterial community resilience were different in the last week of recovery. Predator resilience (based on active predator density) also varied among the three predators but converged over time.

Our results highlight that extreme heat events can be more detrimental to microbial prey communities than microbial predators when microbial predators can exhibit thermal acclimation (e.g. change in body size or become inactive) to overcome heat stress. Such thermal acclimation may promote predator resilience after extreme heat events.

A free Plain Language Summary can be found within the Supporting Information of this article.
Collateral diseases: Aquaculture impacts on wildlife infections
Authors: Bouwmeester Mark M. , Goedknegt M. Anouk , Poulin Robert , Thieltges David W.
Published: October 2020

Aquaculture is a promising source of fish and other aquatic organisms to ensure human food security but it comes at the price of diverse environmental impacts. Among others, these include diseases which often thrive under the conditions in aquaculture settings and can cause high economic losses. These diseases may also affect wildlife, however, the impacts of aquaculture on disease dynamics in wild species in surrounding ecosystems are poorly understood.

In this Review, we provide a conceptual framework for studying the effects of aquaculture on wildlife diseases, and illustrate the different mechanisms identified with examples from the literature. In addition, we highlight further research needs and provide recommendations for management and policy.

We identified five potential means by which farmed populations may alter wildlife disease dynamics: (a) farmed species may co‐introduce parasites to the new environment, which infect wild conspecifics without infecting other species (intraspecific parasite spillover); (b) these co‐introduced parasites from farmed species may infect other wild host species potentially leading to emerging diseases (interspecific parasite spillover); (c) parasites from other wild host species may infect farmed species, amplifying parasite numbers and increasing parasite infections when spilling back to wild hosts (interspecific parasite spillback); (d) farmed species may acquire parasites from wild conspecifics, increasing parasite population size and subsequently raising infection loads in the wild host population (intraspecific parasite spillback); and (e) farmed species may be neither hosts nor parasites, but affect the transmission of parasites between wild host species (transmission interference). Although these mechanisms can alter wildlife disease dynamics, we found large knowledge gaps regarding collateral disease impacts and strong biases in terms of production countries, aquaculture practices and host taxa.

Synthesis and applications. The strong potential for aquaculture to affect the dynamics of diseases in wildlife populations calls for the consideration of collateral disease impacts in risk assessments and biosecurity protocols regarding aquaculture. In particular, comprehensive parasite inventories of both farmed and wild hosts as well as disease monitoring in wildlife surrounding farms will be necessary to increase our knowledge on aquaculture impacts on wildlife disease and to develop adequate prevention and mitigation measures.
Finding clarity in ecological outcomes using empirical integrated social–ecological systems: A case study of agriculture‐dependent grassland birds
Authors: Allen Michael C. , Lockwood Julie L. , Burger Joanna
Published: October 2020

Efforts to monitor and conserve populations and ecosystems in human‐dominated landscapes can benefit from an empirical social–ecological systems approach.

Here we illustrate how latent variable structural equation modelling of regional time series data can effectively describe interconnected drivers of population fluctuations in dynamic landscapes and can help to reveal previously unknown system drivers.

Using a declining farmland‐dependent bird species (Ammodramus savannarum) in the eastern United States (1994–2015) as a case study, our analysis reveals how farm management decisions drive population fluctuations (R2 = 20%), while management is in turn highly influenced by climate (R2 = 23%–51%), but not by regional conservation spending.

Synthesis and applications. Structural equation modelling revealed potential social–ecological pathways for halting regional population declines in a grassland bird, the Grasshopper Sparrow. Lower population growth rates followed years of higher hay yields (~4 percentage points per metric ton increase in hay yield) and later harvests (~2 percentage points per 10‐day delay in harvest). Thus, one pathway for stabilising regional populations could involve compensating farmers for reducing hay harvests, potentially requiring a six‐fold increase in current annual agri‐environmental conservation spending.
Crop pollination services: Complementary resource use by social vs solitary bees facing crops with contrasting flower supply
Authors: Bänsch Svenja , Tscharntke Teja , Gabriel Doreen , Westphal Catrin
Published: October 2020

Many farmers are facing high economic risks if pollinator declines continue or temporal and spatial variation in wild bee communities cause reduced pollination services. Co‐flowering crops might compete for pollinators, while they also might facilitate the delivery of pollination services. This rarely studied topic is of particular interest with respect to the foraging decisions of bees from different functional groups and when more sparsely and mass‐flowering crops are in bloom at the same time.

The abundance of honey bees, bumble bees and solitary bees in strawberry fields was quantified with transect walks along a gradient of oilseed rape (OSR) availability (product of OSR land cover and temporally changing OSR flower cover). We established a pollination experiment with pollination treatments (open‐, wind‐ and self‐pollination) to study the effects of insect pollination on strawberry fruit weight and quality.

Changes in OSR availability exhibited contrasting effects on social versus solitary bees in strawberry fields. Bumble bees and honey bees were less abundant in strawberry fields when OSR availability was high, whereas solitary bees were facilitated. With more strawberry flowers, we found more bees in general.

When flowers were open‐pollinated, they resulted in heavier fruits with better commercial grades compared to wind‐ and self‐pollinated flowers. A higher bee abundance enhanced the strawberry fruit weight and quality but depended on flower order and variety.

Synthesis and applications. Sparsely flowering crops may compete with mass‐flowering crops for social bee pollinators, while solitary pollinators in the field might be evenly facilitated. To ensure best fruit weight and quality, it can be beneficial to support bee abundance in the field. While some social and solitary bee species can be managed for pollination services, wild bees, in particular solitary species, should be conserved and promoted for stable crop pollination services in dynamic agricultural landscapes.
Wildflower strips enhance wild bee reproductive success
Authors: Ganser Dominik , Albrecht Matthias , Knop Eva
Published: October 2020

Intensification of agriculture has resulted in a simplification and fragmentation of agroecosystems. Yet, its impact on the reproductive success and population dynamics of wild bees, and how adverse effects can be mitigated, remains poorly understood.

We established populations of seven solitary bee species varying in body size in experimentally sown wildflower strips (WFS), existing semi‐natural habitats (SNH; forest edges) and isolated sites lacking WFS and SNH in the local surrounding (350 m radius) to test (a) whether the wild bee species use planted flowers of WFS to provision offspring with pollen, (b) whether vicinity to WFS reduces their foraging trip duration, (c) parasitism rate and (d) whether it increases bee reproductive success of nesting populations. Furthermore, we tested whether the effect size depends on the body size of the bee species considered.

We show that wild bees nesting in WFS provisioned their offspring primarily with pollen from plants of WFS. This led to shorter foraging trips of all bee species nesting in WFS compared to bees nesting in isolated (unrestored) sites and overall increased reproductive success (i.e. more viable offspring). Reproductive success of bees nesting in WFS was also higher, and parasitism rates lower, compared to bees nesting at forest edges. Smaller—potentially less mobile—bee species benefitted more than larger ones from WFS plantings in terms of reproductive success.

Synthesis and applications. Our findings demonstrate that diverse WFS can enhance the reproductive success of multiple solitary wild bee species, thereby mitigating negative impacts of agroecosystem simplification through the provision of suitable floral resources and reduced foraging times required for offspring provisioning. Our study further indicates that a relatively fine‐meshed network of wildflower plantings and nesting habitats is required to most effectively enhance reproduction and populations of solitary bees in agricultural landscapes.
Chikungunya infection in pregnancy – reassuring maternal and perinatal outcomes: a retrospective observational study
Authors: Foeller ME , Nosrat C , Krystosik A , Noel T , Gérardin P , Cudjoe N , Mapp‐Alexander V , Mitchell G , Macpherson C , Waechter R , LaBeaud AD
Published: October 2020

Objective

To evaluate pregnancy and neonatal outcomes, disease severity, and mother‐to‐child transmission of pregnant women with Chikungunya infection (CHIKV).

Design

Retrospective observational study.

Setting

Grenada.

Population

Women who gave birth during a Chikungunya outbreak between January 2014 and September 2015 were eligible.

Methods

This descriptive study investigated 731 mother‐infant pairs who gave birth during a CHIKV outbreak. Women and infants underwent serological testing for CHIKV by ELISA.

Main outcome measures

Primary outcomes: composite pregnancy complication (abruption, vaginal bleeding, preterm labour/cervical incompetence, cesarean delivery for fetal distress/abruption/placental abnormality or delivery for fetal distress) and composite neonatal morbidity.

Results

Of 416 mother‐infant pairs, 150 (36%) had CHIKV during pregnancy, 135 (33%) had never had CHIKV, and 131 (31%) had CHIKV outside of pregnancy. Mean duration of joint pain was shorter among women infected during pregnancy (μ = 898 days, σ = 277 days) compared with infections outside of pregnancy (μ = 1064 days, σ = 244 days) (P < 0.0001). Rates of pregnancy complications (RR = 0.76, P = 0.599), intrapartum complications (RR = 1.50, P = 0.633), and neonatal outcomes were otherwise similar. Possible mother‐to‐child transmission occurred in two (1.3%) mother‐infant pairs and two of eight intrapartum infections (25%).

Conclusion

CHIKV infection during pregnancy may be protective against long‐term joint pain sequelae that are often associated with acute CHIKV infection. Infection during pregnancy did not appear to pose a risk for pregnancy complications or neonatal health, but maternal infection just prior to delivery might have increased risk of mother‐to‐child transmission of CHIKV.

Tweetable abstract

Chikungunya infection did not increase risk of pregnancy complications or adverse neonatal outcomes, unless infection was just prior to delivery.
Recent advances on the application of UV‐LED technology for microbial inactivation: Progress and mechanism
Authors: Kebbi Yasmine , Muhammad Aliyu Idris , Sant'Ana Anderson S. , do Prado‐Silva Leonardo , Liu Donghong , Ding Tian
Published: October 2020

Conventional technologies for the inactivation of microorganisms in food products have their limitations, especially changes in quality attributes that have led to quality deterioration, low consumer acceptance, impact on the environment, and potential health hazards (carcinogens). Ultraviolet (UV) light is an emerging promising nonthermal technology employed for microbial inactivation in water, liquid, and solid food products to curtail the limitations above. This review provides an insight into UV light‐emitting diodes (UV‐LEDs)' potential as an alternative to the traditional UV lamps for microbial inactivation in liquid and solid media. Also, the mechanisms of inactivation of lone and combined UVA‐, UVB‐, and UVC‐LEDs were discussed. The strategies utilized to improve the efficacy between the UV‐LED treatments at various wavelengths were summarized. Combining different UV‐LEDs treatments at different wavelengths have a synergistic effect and suppression of microbial cell reactivation. The UV‐LED‐based advanced oxidation processes (AOPs) also have high germicidal action against numerous microorganisms and are efficient for the degradation of micropollutants. Among the UV‐LEDs discussed, UVC‐LED has the most antimicrobial effect with the most efficient micropollutants decomposition with regards to UV‐LED‐based AOPs. This review has provided vital information for future application, development, and customization of UV‐LED systems that can meet the food and water safety requirements and energy efficiency.