bluuebunny/crossref_metadata_2025 huggingface dataset:
Post-transcriptional circadian regulation in macrophages organizes temporally distinct immunometabolic states
Authors: Collins Emily J. , Cervantes-Silva Mariana P. , Timmons George A. , O'Siorain James R. , Curtis Annie M. , Hurley Jennifer M.
Published: January 2021

Our core timekeeping mechanism, the circadian clock, plays a vital role in immunity. Although the mechanics of circadian control over the immune response is generally explained by transcriptional activation or repression derived from this clock's transcription-translation negative-feedback loop, research suggests that some regulation occurs beyond transcriptional activity. We comprehensively profiled the transcriptome and proteome of murine bone marrow-derived macrophages and found that only 15% of the circadian proteome had corresponding oscillating mRNA, suggesting post-transcriptional regulation influences macrophage clock regulatory output to a greater extent than any other tissue previously profiled. This regulation may be explained by the robust temporal enrichment we identified for proteins involved in degradation and translation. Extensive post-transcriptional temporal-gating of metabolic pathways was also observed and further corresponded with daily variations in ATP production, mitochondrial morphology, and phagocytosis. The disruption of this circadian post-transcriptional metabolic regulation impaired immune functionality. Our results demonstrate that cell-intrinsic post-transcriptional regulation is a primary driver of circadian output in macrophages and that this regulation, particularly of metabolic pathways, plays an important role in determining their response to immune stimuli.
Oxidation-induced three-dimensional morphological changes in Ni nanoparticles observed by coherent X-ray diffraction imaging
Authors: Ahn Kangwoo , Cho In Hwa , Kim Junhyung , Lee Su Yong , Sung Daeho , Jung Chulho , Song Changyong , Kang Hyon Chol , Noh Do Young
Published: January 2021

Three-dimensional structures of Ni nanoparticles undergoing significant morphological changes on oxidation were observed non-destructively using coherent X-ray diffraction imaging. The Ni particles were oxidized into Ni1O1 while forming pores of various sizes internally. For each Ni nanoparticle, one large void was identified at a lower corner near the interface with the substrate. The porosity of the internal region of the agglomerated Ni oxide was about 38.4%. Regions of high NiO density were mostly observed at the outer crust of the oxide or at the boundary with the large voids. This research expands our understanding of general catalytic reactions with direct observation of oxidation-induced nanoscale morphological changes.
The internationalisation process of UK SMEs: exporting and non-exporting behaviours based on a four forces behavioural model
Authors: Coudounaris Dafnis N.
Published: January 2021

Purpose

This study aims to develop a new internationalisation model to describe the exporting and non-exporting behaviours of small and medium sized enterprises (SMEs) and then applying it to a sample of UK SMEs. The conceptual model consists of four forces leading to a successful business.

Design/methodology/approach

The sample is a stratified one taken from KOMPASS directory and focussing on the Greater Manchester area. In total, 250 firms were chosen to be the population of this survey. In total, 110 surveys were received by email i.e. 24 non-exporters and 86 exporters that were fully completed.

Findings

The four forces of the model include the non-exporting activity, the activity before and after the first export order, differences and similarities between non-exporters and exporters and the regular exporting activity. This model’s findings demonstrate important empirical determinants related to four forces, which, in turn, shape the successful exporting activity.

Originality/value

The empirical evidence from the study suggests that the major differences between non-exporters and exporters, which include the differences in management perceptions towards exporting, and the differences and similarities of firm and management characteristics, explain only to some degree what constitutes successful exporting behaviour. The model is considered useful for smaller businesses located in the UK. The study highlights the importance of firms before and after the first export order, which provides insights for managers of firms about going through with the first export order rather than withdrawing from this effort. The study reveals the motivations for exporting, the timing, the modes through which firms export, firms’ management characteristics and attitudinal differences between exporters and non-exporters, which are essential for practitioners.
Antecedents of employee thriving at work: The roles of formalization, ethical leadership, and interpersonal justice
Authors: Rahaman H. M. Saidur , Stouten Jeroen , Decoster Stijn , Camps Jeroen
Published: January 2021

In this paper, we examine whether the presence of a mechanistic structure (i.e. formalization) hinders or facilitates employee thriving at work. In doing so, we examine formalization as an antecedent of employee thriving at work. Specifically, we examine why and when formalization, as an important contextual factor, may facilitate employee thriving at work. We hypothesize that the positive relation between formalization and employees' thriving at work is mediated by their interpersonal justice perceptions. Furthermore, we hypothesize that ethical leadership moderates the indirect relationship between formalization and employee thriving at work via interpersonal justice. As such, this relationship is stronger in the presence of relatively high (rather than relatively low) levels of ethical leadership. Results from a two‐wave field study provide support for our hypotheses. We also discuss the theoretical and practical implications, limitations, and future research directions for our findings.
Work and resilience: Care leavers' experiences of navigating towards employment and independence
Authors: Furey Rosemary , Harris‐Evans Jean
Published: January 2021

Poor education and employment outcomes have long been associated with care experienced young people transitioning into independence, even after adjusting for prior disadvantage. In the United Kingdom, such young people are generally referred to as care leavers. Policies that aim to reduce the gap between care leavers and non‐care experienced young people's success transitioning to employment and independence have had limited success. This paper draws on a qualitative methodology that utilized theories of resilience, to glean a range of perspectives from both care leavers and their employers. All the participants were engaged in a U.K. local authority's initiative to support care leavers into employment. Drawing on resilience theory, resilience was found to be located in a complex interaction between a resilience enabling environment and, crucially, emotionally supportive networks. Uniquely, we argue that emotional support, drawn from such networks, is the key factor that facilitates young people navigating towards such resources, leading to successful outcomes. Previous studies have underplayed this aspect in favour of more tangible resources. Attention to strengthening emotional support networks is thus identified as a significant factor that supports transition to employment and successful independence for care leavers.
Guided bone regeneration of chronic non‐contained bone defects using a volume stable porous block TiO2 scaffold: An experimental in vivo study
Authors: Thieu Minh Khai Le , Haugen Håvard Jostein , Sanz‐Esporrin Javier , Sanz Mariano , Lyngstadaas Ståle Petter , Verket Anders
Published: January 2021

Objectives

To evaluate new lateral bone formation and lateral volume augmentation by guided bone regeneration (GBR) in chronic non‐contained bone defects with the use of a non‐resorbable TiO2‐block.

Materials and methods

Three buccal bone defects were created in each hemimandible of eight beagle dogs and allowed to heal for 8 weeks before treatment by GBR. Each hemimandible was randomly allocated to 4‐ or 12‐week healing time after GBR, and three intervention groups were assigned by block randomization: TiO2 block: TiO2‐scaffold and a collagen membrane, DBBM particles: Deproteinized bovine bone mineral (DBBM) and a collagen membrane, Empty control: Collagen membrane only.

Microcomputed tomography (microCT) was used to measure the lateral bone formation and width augmentation. Histological outcomes included descriptive analysis and histomorphometric measurements.

Results

MicroCT analysis demonstrated increasing new bone formation from 4 to 12 weeks of healing. The greatest width of mineralized bone was seen in the empty controls, and the largest lateral volume augmentation was observed in the TiO2 block sites. The DBBM particles demonstrated more mineralized bone in the grafted area than the TiO2 blocks, but small amounts and less than the empty control sites.

Conclusion

The TiO2 blocks rendered the largest lateral volume augmentation but also less new bone formation compared with the DBBM particles. The most new lateral bone formation outward from the bone defect margins was observed in the empty controls, indicating that the presence of either graft material leads to slow appositional bone growth.
Effect of Hepatitis C donor status on heart transplantation outcomes in the United States
Authors: Doulamis Ilias P. , Tzani Aspasia , Moustakidis Serafeim , Kampaktsis Polydoros N. , Briasoulis Alexandros
Published: January 2021

Background

Recent studies demonstrated safety and efficacy of heart transplantation (HT) from hepatitis C virus (HCV)‐positive donors. We sought to evaluate the impact of HCV donor status on the outcomes of patients undergoing HT in the United States.

Methods

We analyzed a retrospective cohort of adult patients from the United Network for Organ Sharing (UNOS) database who underwent isolated HT from 2015 until present. Primary outcomes were 30‐day and 1‐year overall mortality. Secondary outcomes included risk for graft failure and overall survival, incident stroke and need for dialysis during the available follow‐up period. All end points were evaluated according to HCV status.

Results

All‐cause 30‐day and 1‐year mortality was similar between the two groups (3.4% vs 3.2%, P = .973 and 6.9% vs 7.8%, P = .769, respectively, for patients receiving heart grafts from HCV+ vs. HCV− donors). Graft failure was 12.8% (95% CI: 8%‐19%) and 15.2% (95 CI: 15%‐16%) in the HCV+ and HCV− groups, respectively (P = .92 and P = .68). Competing risk regression analysis for re‐operation showed a non‐significant trend for higher risk for re‐transplantation in the HCV+ group (HR: 2.71; 95% CI: 0.83, 8.80, P = .097).

Conclusion

HCV donor status does not seem to negatively affect the outcomes of HT in the U.S population.
Estimated dietary sodium intake in Thailand: A nationwide population survey with 24‐hour urine collections
Authors: Chailimpamontree Worawon , Kantachuvesiri Surasak , Aekplakorn Wichai , Lappichetpaiboon Raweewan , Sripaiboonkij Thokanit Nintita , Vathesatogkit Prin , Kunjang Ananthaya , Boonyagarn Natthida , Sukhonthachit Penmat , Chuaykarn Narinphop , Sonkhammee Patthrapon , Khunsaard Payong , Nuntapanich Phassakon , Charoenbut Pattaraporn , Thongchai Comsun , Uttarachai Apinya , Kwankhoom Wisrut , Rattanakanahutanon Fuangfah , Ruangchai Krich , Yanti Nadchar , Sasang Natnapa , Bunluesin Sushera , Garg Renu
Published: January 2021

Thailand has committed to reducing population sodium intake by 30% by 2025. However, reliable nationally representative data are unavailable for monitoring progress toward the goal. We estimated dietary sodium consumption using 24‐hour urinary analyses in a nationally representative, cross‐sectional population‐based survey. We selected 2388 adults (aged ≥ 18 years) from the North, South, North‐east, Central Regions, and Bangkok, using multi‐stage cluster sampling. Mean sodium excretion was inflated by 10% to adjust for non‐urinary sources. Multivariate logistic regression was performed to assess factors associated with sodium consumption ≥ 2000 mg. Among 1599 (67%) who completed urine collection, mean age was 43 years, 53% were female, and 30% had hypertension. Mean dietary sodium intake (mg/day) was 3636 (±1722), highest in South (4108 ± 1677), and lowest in North‐east (3316 ± 1608). Higher sodium consumption was independently associated with younger age (Adjusted Odds Ratio (AOR) 2.81; 95% Confidence interval (CI): 1.53‐5.17; p = .001); higher education (AOR 1.79; 95% CI: 1.19‐2.67; p = .005), BMI ≥ 25 (AOR 1.55; 95% CI: 1.09‐2.21; p=.016), and hypertension (AOR 1.58; 95% CI: 1.02‐2.44; p = .038). Urine potassium excretion was 1221 mg/day with little variation across Regions. Estimated dietary sodium consumption in Thai adults is nearly twice as high as recommended levels. These data provide a benchmark for future monitoring.
Metformin alleviates allergic airway inflammation and increases Treg cells in obese asthma
Authors: Guo Yimin , Shi Jianting , Wang Qiujie , Hong Luna , Chen Ming , Liu Shanying , Yuan Xiaoqing , Jiang Shanping
Published: January 2021

Obesity increases the morbidity and severity of asthma, with poor sensitivity to corticosteroid treatment. Metformin has potential effects on improving asthma airway inflammation. Regulatory T cells (Tregs) play a key role in suppressing the immunoreaction to allergens. We built an obese asthmatic mouse model by administering a high‐fat diet (HFD) and ovalbumin (OVA) sensitization, with daily metformin treatment. We measured the body weight and airway inflammatory status by histological analysis, qRT‐PCR, and ELISA. The percentage of Tregs was measured by flow cytometry. Obese asthmatic mice displayed more severe airway inflammation and more significant changes in inflammatory cytokines. Metformin reversed the obese situation and alleviated the airway inflammation and remodelling with increased Tregs and related transcript factors. The anti‐inflammatory function of metformin may be mediated by increasing Tregs.
Thyroid Hormone Supplementation and All‐Cause Mortality in Community‐Dwelling Older Adults: Results from the Baltimore Longitudinal Study of Aging
Authors: Abbey Enoch J. , McGready John , Ferrucci Luigi , Simonsick Eleanor M. , Mammen Jennifer S.R.
Published: January 2021

Background

Although elevated thyrotropin (TSH) is common in older adults, controversy exists over what degree of elevation should be treated with thyroid hormone supplements. Isolated, elevated TSH in this population can be consistent with aging‐related adaptations rather than indicative of primary thyroid disease, raising the possibility that thyroid hormone replacement may be harmful.

Objectives

Determine the association between all‐cause mortality and levothyroxine use among older adults.

Design

Longitudinal observational study.

Setting

Baltimore Longitudinal Study of Aging.

Participants

One thousand two hundred and fifty eight community dwelling adult participants aged 65+ with an average of 9 years of follow up.

Measurements

Thyroid and pituitary hormone levels and thyroid hormone supplementation were determined at each visit. Incident rate ratios (IRR) for all‐cause mortality were calculated using time‐dependent Poisson regression models to accommodate the varying start times. To isolate the effects of hormone replacement from its effects on TSH, the association between treatment and all‐cause mortality was analyzed in participants with stable thyroid function status throughout follow‐up (N = 638).

Results

Thyroid hormone supplementation was not associated with a significant increase all‐cause mortality in the subsequent year in the fully adjusted model (IRR = 1.40, 95% confidence interval (CI) = 0.93–2.12). In a stratified analysis of euthyroid participants, thyroid hormone use was associated with significantly greater mortality, with an adjusted IRR = 1.81 (95% CI = 1.10–2.98).

Conclusion

The increased mortality associated with thyroid hormone use among the subclass of euthyroid community dwelling older adults is consistent with a model in which TSH elevation can result from a variety of underlying pathophysiologic processes, not all of which should be treated with thyroid hormone supplementation. Clinicians should consider overall clinical status when interpreting an isolated elevated TSH in older adults.
Circuit selectivity in drug versus natural reward seeking behaviors
Authors: Nall Rusty W. , Heinsbroek Jasper A. , Nentwig Todd B. , Kalivas Peter W. , Bobadilla Ana‐Clara
Published: January 2021

Substance use disorder (SUD) is characterized, in part by behavior biased toward drug use and away from natural sources of reward (e.g., social interaction, food, sex). The neurobiological underpinnings of SUDs reveal distinct brain regions where neuronal activity is necessary for the manifestation of SUD‐characteristic behaviors. Studies that specifically examine how these regions are involved in behaviors motivated by drug versus natural reward allow determinations of which regions are necessary for regulating seeking of both reward types, and appraisals of novel SUD therapies for off‐target effects on behaviors motivated by natural reward. Here, we evaluate studies directly comparing regulatory roles for specific brain regions in drug versus natural reward. While it is clear that many regions drive behaviors motivated by all reward types, based on the literature reviewed we propose a set of interconnected regions that become necessary for behaviors motivated by drug, but not natural rewards. The circuitry is selectively necessary for drug seeking includes an Action/Reward subcircuit, comprising nucleus accumbens, ventral pallidum, and ventral tegmental area, a Prefrontal subcircuit comprising prelimbic, infralimbic, and insular cortices, a Stress subcircuit comprising the central nucleus of the amygdala and the bed nucleus of the stria terminalis, and a Diencephalon circuit including lateral hypothalamus. Evidence was mixed for nucleus accumbens shell, insular cortex, and ventral pallidum. Studies for all other brain nuclei reviewed supported a necessary role in regulating both drug and natural reward seeking. Finally, we discuss emerging strategies to further disambiguate the necessity of brain regions in drug‐ versus natural reward‐associated behaviors.

image
Linking changes in chlorophyll a fluorescence with drought stress susceptibility in mung bean [Vigna radiata (L.) Wilczek]
Authors: Bano Hussan , Athar Habib‐ur‐Rehman , Zafar Zafar Ullah , Kalaji Hazem M. , Ashraf Muhammad
Published: January 2021

In the present study, the mung bean cv. NM‐13‐1Tol was selected as drought‐tolerant and NM‐54Sens as drought‐sensitive. The effects of progressive drought (16 days) on the photosystem II (PSII) activity was assessed using OJIP and JIP‐test in the selected two mung bean cultivars differing in drought tolerance. Drought stress reduced the relative water content to 70% (at threshold) and 62% (below the threshold) in cv.NM‐13‐1Tol and NM‐54sens, respectively. The greater reduction in quantum yield of PSII in cv.NM‐54sens due to drought stress was due to PSII photodamage. Raw OJIP induction curves and Fo and Fm normalised curves showed that significant changes in fluorescence occurred at the O, J, I and P steps only in cv. NM‐54sens. Double normalised differential kinetics indicated adverse effects at the antennae, oxygen‐evolving complex and intersystem electron acceptors in cv.NM54sens. Moreover, JIP‐test analysis showed that drought stress caused a greater decrease in performance index (PIABS) in cv.NM‐54sens as compared to that in cv. NM‐13‐1Tol, which is associated with an increase in Vj, rate of accumulation of closed reaction centres (Mo), energy fluxes for absorption (ABS/RC), trapping (TRo/RC), electron transport (ETo/RC), and dissipation of absorbed energy as heat (DIo/RC). In conclusion, two‐week drought stress reduced the RWC below the threshold in cv.NM54sens, which resulted in damages at the donor and acceptor sides of PSII. However, cv.NM‐13‐1Tol somehow maintained the RWC around the threshold and thus protected PSII. Of various JIP‐test parameters, PIABS, Fv/Fm, Vj and Mo are key indicators of drought stress tolerance in mung bean cultivars.
Crosstalk between phytohormones and secondary metabolites in the drought stress tolerance of crop plants: A review
Authors: Jogawat Abhimanyu , Yadav Bindu , Chhaya  , Lakra Nita , Singh Amit Kumar , Narayan Om Prakash
Published: January 2021

Drought stress negatively affects crop performance and weakens global food security. It triggers the activation of downstream pathways, mainly through phytohormones homeostasis and their signaling networks, which further initiate the biosynthesis of secondary metabolites (SMs). Roots sense drought stress, the signal travels to the above‐ground tissues to induce systemic phytohormones signaling. The systemic signals further trigger the biosynthesis of SMs and stomatal closure to prevent water loss. SMs primarily scavenge reactive oxygen species (ROS) to protect plants from lipid peroxidation and also perform additional defense‐related functions. Moreover, drought‐induced volatile SMs can alert the plant tissues to perform drought stress mitigating functions in plants. Other phytohormone‐induced stress responses include cell wall and cuticle thickening, root and leaf morphology alteration, and anatomical changes of roots, stems, and leaves, which in turn minimize the oxidative stress, water loss, and other adverse effects of drought. Exogenous applications of phytohormones and genetic engineering of phytohormones signaling and biosynthesis pathways mitigate the drought stress effects. Direct modulation of the SMs biosynthetic pathway genes or indirect via phytohormones' regulation provides drought tolerance. Thus, phytohormones and SMs play key roles in plant development under the drought stress environment in crop plants.
Phylogeny and revision of the ‘Cubitermes complex’ termites (Termitidae: Cubitermitinae)
Authors: Hellemans Simon , Deligne Jean , Roisin Yves , Josens Guy
Published: January 2021

The phylogeny of the genus Cubitermes Wasmann was reconstructed using two mitochondrial genes (COI and COII) and a fragment of the nuclear 28S rDNA, including samples of Apilitermes Holmgren, Crenetermes Silvestri, Megagnathotermes Silvestri and Thoracotermes Wasmann. Based on our analyses, we recovered these genera within a paraphyletic Cubitermes clade. Cubitermes species are distributed between five main clades, highly reflective of their enteric valve armatures (EVAs). Consequently, Cubitermes is here divided into five monophyletic genera based on phylogenetic analyses and EVAs: Cubitermes (sensu stricto), Isognathotermes Sjöstedt, Nitiditermes Emerson, Polyspathotermes Josens & Deligne, gen.n., and Ternicubitermes Josens & Deligne, gen.n. Moreover, the two species of Megagnathotermes included in this study, exhibiting different EVAs, are phylogenetically distant: M. katangensis Sjöstedt belongs in the genus Polyspathotermes, while M. notandus Silvestri remains as a monotypic genus. During the evolution of the Cubitermes complex, sclerotized EVA spatulae appeared twice independently: three or six spatulae in Polyspathotermes (sulcifrons and oblectatus patterns) and two jaw‐like spatulae in Nitiditermes (sankurensis pattern), which is absent in some species (oculatus pattern). Zoobank registration:
http://zoobank.org/urn:lsid:zoobank.org:pub:576AAFF8‐63C6‐4962‐A8F5‐75C9317AEA7B.
Wear Behavior of TiB2/GNPs and B4C/GNPs Reinforced AA6061 Matrix Composites
Authors: Polat Safa , Sun Yavuz , C¸evik Engin
Published: January 2021

In this study, it was aimed to investigate the effects of reinforcements used for improving the thermal properties of AA6061 alloy on wear resistance. For this purpose, AA6061 matrix composites were produced by pressure infiltration method using ceramic microparticles (TiB2 and B4C) and graphene nanoparticles (GNPs). The produced composites were first characterized by porosity measurement, X-ray diffraction (XRD), and scanning electron microscopy (SEM) analysis. Then, the wear behavior was examined under three different loads (20–40–60 N) with the reciprocating ball on the flat method in a dry environment. Specific wear-rates were calculated according to the Archard principle by measuring the depth and width of the traces after tests with a profilometer. Wearing mechanisms were determined with the help of optical and microstructure images. According to the obtained results, it was found that B4C + GNPs reinforced samples were more resistant to abrasion at low loads, but TiB2 + GNPs reinforced samples were higher at higher loads.
Louver Slot Cooling and Full-Coverage Film Cooling With a Combination Internal Coolant Supply
Authors: Click Austin , Ligrani Phillip M. , Hockensmith Maggie , Knox Joseph , Larson Chandler , Fairbanks Avery , Liberatore Federico , Patel Rajeshriben , Ho Yin-Hsiang
Published: January 2021

Within the present investigation, a louver slot is employed upstream of an array full-coverage film cooling holes. Cooling air is supplied using a combination arrangement, with cross-flow and impingement together. The louver consists of a row of film cooling holes, contained within a specially designed device that concentrates and directs the coolant from a slot, so that it then advects as a layer downstream along the test surface. This louver-supplied coolant is then supplemented by coolant which emerges from different rows of downstream film cooling holes. The same coolant supply passage is employed for the louver row of holes, as well as for the film cooling holes, such that different louver and film cooling mass flowrates are set by different hole diameters for the two different types of cooling holes. The results are different from data provided by past investigations, because of the use and arrangement of the louver slot, and because of the unique coolant supply configurations. The experimental results are given for mainstream Reynolds numbers from 107,000 to 114,000. Full-coverage blowing ratios are constant with streamwise location along the test surface and range from 3.68 to 5.70. Corresponding louver slot blowing ratios then range from 1.72 to 2.65. Provided are heat transfer coefficient and adiabatic effectiveness distributions, which are measured along the mainstream side of the test plate. Both types of data show less variation with streamwise development location, relative to results obtained without a louver employed, when examined at the same approximate effective blowing ratio, mainstream Reynolds number, cross-flow Reynolds number, and impingement jet Reynolds number. When compared at the same effective blowing ratio or the same impingement jet Reynolds number, spanwise-averaged heat transfer coefficients are consistently lower, especially for the downstream regions of the test plate, when the louver is utilized. With the same type of comparisons, the presence of the louver slot results in significantly higher values of adiabatic film cooling effectiveness (spanwise-averaged), particularly at and near the upstream portions of the test plate. With such characteristics, dramatic increases in thermal protection are provided by the presence of the louver slot, the magnitudes of which vary with the experimental condition and test surface location.
Development and Performance of Roof-Based Building-Integrated Photovoltaic-Thermal Systems: A Review
Authors: Cheng Xu , Zou Zhijun , Yu Guoqing , Ma Guobin , Ye Hai , Li Yilin , Liu Hongzhi
Published: January 2021

A building-integrated photovoltaic-thermal (BIPVT) system integrates building envelope and photovoltaic-thermal collectors to produce electricity and heat. In this paper, the electrical and thermal performance of roof-based BIPVT systems developed in the recent two decades and their effects on heating and cooling load of the building are reviewed. According to the use of thermal energy from the photovoltaic (PV) panels, the roof-based BIPVT are classified into three classes: cooling of PV, air heating, and water heating. Each class is further divided into several types according to the designs of the integrated PV roofs. Compared with BIPV systems, the total efficiency of most BIPVT systems is significantly improved. However, the decrease in electricity output and adverse impact on the indoor environment is also found for some designs of BIPVT systems in some climates. The advantages and disadvantages of various designs are discussed. Issues to be further studied in the future are also provided in this review.
A Cable-Driven Parallel Robot With Full-Circle End-Effector Rotations
Authors: Métillon Marceau , Cardou Philippe , Subrin Kévin , Charron Camilo , Caro Stéphane
Published: January 2021

Cable-driven parallel robots (CDPRs) offer high payload capacities, large translational workspace and high dynamic performances. The rigid base frame of the CDPR is connected in parallel to the moving platform using cables. However, their orientation workspace is usually limited due to cable/cable and cable/moving platform collisions. This paper deals with the design, modelling and prototyping of a hybrid robot. This robot, which is composed of a CDPR mounted in series with a Parallel Spherical Wrist (PSW), has both a large translational workspace and an unlimited orientation workspace. It should be noted that the six-degrees-of-freedom (DOF) motions of the moving platform of the CDPR, namely, the base of the PSW, and the three-DOF motion of the PSW are actuated by means of eight actuators fixed to the base. As a consequence, the overall system is underactuated, and its total mass and inertia in motion is reduced.
Experimental and Numerical Analysis of the Powder Flow in a Multi-Channel Coaxial Nozzle of a Direct Metal Deposition System
Authors: Pant Piyush , Chatterjee Dipankar , Samanta Sudip Kumar , Lohar Aditya Kumar
Published: January 2021

The work explores the powder transport process, using numerical simulation to address the dynamics of the powder flow in an in-house built multi-channel coaxial nozzle of a direct metal deposition (DMD) system. The fluid turbulence is handled by the standard k–ɛ and k–ω turbulence models, and the results are compared in order to predict their suitability. An image-based technique using CMOS camera is adopted to determine the powder flow characteristics. The model is validated with the in-house experimental results and verified available results in the literature. The findings of this work confirms the application of the k–ω model for powder gas flow investigations in blown powder additive manufacturing (AM) processes due to its better predictive capability. The proposed model will assist in simulating the direct metal deposition process.
Sizing and Operation of a Hybrid Energy Plant Composed of Industrial Gas Turbines, Renewable Energy Systems, and Energy Storage Technologies
Authors: Bahlawan Hilal , Gambarotta Agostino , Losi Enzo , Manservigi Lucrezia , Morini Mirko , Spina Pier Ruggero , Venturini Mauro
Published: January 2021

Hybrid energy plants (HEPs), which include both fossil fuel technologies and renewable energy systems, can provide an important step toward a sustainable energy supply. In fact, the hybridization of renewable energy systems with gas turbines (GTs), which are fed by fossil fuels allows an acceptable compromise, so that high fossil fuel efficiency and high share of renewables can be potentially achieved. Moreover, electrical and thermal energy storage systems increase the flexibility of the energy plant and effectively manage the variability of energy production and demand. This paper investigates the optimal sizing of a HEP, which combines an industrial GT, renewable energy systems, and energy storage technologies. The considered renewable energy system is a photovoltaic system (PV), while the energy storage technologies are electrical energy storage and thermal energy storage. Moreover, a compression chiller and a gas boiler (GB) are also considered. For this purpose, the load profiles of electricity, heating, and cooling during a whole year are taken into account for the case study of the Campus of the University of Parma (Italy). The sizing optimization problem of the different technologies composing the HEP is solved by using a genetic algorithm, with the goal of minimizing the primary energy consumption (PEC). Moreover, different operation strategies are analyzed and compared so that plant operation is also optimized. The results demonstrate that the optimal sizing of the HEP, coupled with the optimized operation strategy, allows high average cogeneration efficiency (up to 84%), thus minimizing PEC.
Numerical Study of Tip Leakage Vortex Around a NACA0009 Hydrofoil
Authors: Bi Zhen , Shao Xueming , Zhang Lingxin
Published: January 2021

In the tip clearance flow, the dominant vortex is the tip leakage vortex (TLV), which has a significant impact on the hydraulic and cavitation performance of axial flow machineries. In order to reveal the impact mechanism of the gap size on the TLV, gap flows with two gap sizes, i.e., τ=0.2 (2 mm) and τ=1.0 (10 mm), are numerically investigated. A NACA0009 hydrofoil is selected to create the gap flow, with an incoming velocity of 10 m/s and an attack angle of 10 deg. The results show that the two flow cases are significantly different in terms of vortex feature and the leakage flow distribution. In the small gap, a type of jet-pattern flow appears, whereas a type of rolling-pattern flow passes over the large gap. The vertical velocity gradient of the leakage flow has a decisive influence on the TLV trajectory. In addition, for the large gap, the axial velocity in the vortex center exceeds the incoming flow. This jet-like state of axial velocity can be maintained for a long distance, making the vortex more stable. However, the axial velocity in the case of τ=0.2 cannot stay at the jet-like state and rapidly switches to a wake-like state.
A Modified Chezy Formula for One-Dimensional Unsteady Frictional Resistance in Open Channel Flow
Authors: Zhou Junwei , Bao Weimin , Tick Geoffrey R. , Moftakhari Hamed , Li Yu , Cheng Li
Published: January 2021

It has been observed in literature that for unsteady flow conditions the one-to-one relationships between flow depth, cross-sectional averaged velocity, and frictional resistance as determined from steady uniform flow cases may not be appropriate for these more complex flow systems. Thus, a general friction resistance formula needs to be modified through the addition of new descriptive terms to account for flow unsteadiness, in order to eliminate errors due to uniform and steady-flow assumptions. An extended Chezy formula incorporating both time and space partial derivatives of hydraulic parameters was developed using dimensional analysis to investigate the relationship between flow unsteadiness and friction resistance. Results show that the proposed formula performs better than the traditional Chezy formula for simulating real hydrograph cases whereby both formula coefficients are individually identified for each flood event and coefficients are predetermined using other flood events as calibration cases. Although the extended Chezy formula as well as the original Chezy formula perform worse with the increasing degree of flow unsteadiness, its results are less dramatically affected by unsteadiness intensity, thereby improving estimations of flood routing. As a result, it tends to perform much better than traditional Chezy formula for severe flood events. Under more complex conditions whereby peak flooding events may occur predominantly under unsteady flow, the extended Chezy model may provide as a valuable tool for researchers, practitioners, and water managers for assessing and predicting impacts for flooding and for the development of more appropriate mitigation strategies and more accurate risk assessments.
On the Vortical Characteristics of Horn-Like Vortices in Stator Corner Separation Flow in an Axial Flow Pump
Authors: Wang Chaoyue , Wang Fujun , Xie Lihua , Wang Benhong , Yao Zhifeng , Xiao Ruofu
Published: January 2021

The phenomenon of horn-like vortex in stator corner separation flow in an axial flow pump was first reported by Wang et al. (2020, “Investigation on the Horn-Like Vortices in Stator Corner Separation Flow in an Axial Flow Pump,” ASME J. Fluids Eng., 142(7), p. 071208), and the associated external features were preliminarily presented. However, internal vortical characteristics of horn-like vortices, including the distributions of swirling strength, the deformation mechanism of vortex tube and the correlation with pressure fluctuation surge, are not revealed. In this paper, the newly developed vorticity decomposition approach is introduced, and thus more novel quantitative results are provided for the physics of horn-like vortex evolution in an axial flow pump. First, the distributions of absolute swirling strength, relative swirling strength and Liutex spectrum are presented to outline the vortical features of the horn-like vortex fields. Second, the deformation mechanism of the horn-like vortex tube is revealed. It is found that the horn-like vortex spatial evolution can be described by the deformation terms (Liutex stretching term, Liutex dilatation term, and curl term of the pseudo-Lamb vector) controlling the Liutex transport process. These terms constantly act on the horn-like vortex tube in an almost independent way, causing its continuous deformations in the transit process. Third, the quantitative correlation between horn-like vortex transit and pressure fluctuation surge is given. It is proved that periodic vortex transit can cause severe pressure fluctuation that is much larger than that induced by rotor–stator interaction. From multiple perspectives, a clearer evolution process of the horn-like vortex is outlined, which is conducive to controlling the corner separation flows and improving the stability of large-capacity and low-head pumping stations.
Evaluation of Energy Storage Potential of Unconventional Shale Reservoirs Using Numerical Simulation of Cyclic Gas Injection
Authors: Augustine Chad , Johnston Henry , Young David L. , Amini Kaveh , Uzun Ilkay , Kazemi Hossein
Published: January 2021

Compressed air energy storage (CAES) stores energy as compressed air in underground formations, typically salt dome caverns. When electricity demand grows, the compressed air is released through a turbine to produce electricity. CAES in the US is limited to one plant built in 1991, due in part to the inherent risk and uncertainty of developing subsurface storage reservoirs. As an alternative to CAES, we propose using some of the hundreds of thousands of hydraulically fractured horizontal wells to store energy as compressed natural gas in unconventional shale reservoirs. To store energy, produced or “sales” natural gas is injected back into the formation using excess electricity and is later produced through an expander to generate electricity. To evaluate this concept, we performed numerical simulations of cyclic natural gas injection into unconventional shale reservoirs using cmg-gem commercial reservoir modeling software. We tested short-term (diurnal) and long-term (seasonal) energy storage potential by modeling well injection and production gas flowrates as a function of bottom-hole pressure. First, we developed a conceptual model of a single fracture stage in an unconventional shale reservoir to characterize reservoir behavior during cyclic injection and production. Next, we modeled cyclic injection in the Marcellus shale gas play using published data. Results indicate that Marcellus unconventional shale reservoirs could support both short- and long-term energy storage at capacities of 100–1000 kWe per well. The results indicate that energy storage in unconventional shale gas wells may be feasible and warrants further investigation.
An Affordable Linkage-and-Tendon Hybrid-Driven Anthropomorphic Robotic Hand—MCR-Hand II
Authors: Yang Haosen , Wei Guowu , Ren Lei , Qian Zhihui , Wang Kunyang , Xiu Haohua , Liang Wei
Published: January 2021

This paper presents the design, analysis, and development of an anthropomorphic robotic hand coined MCR-hand II. This hand takes the advantages of both the tendon-driven and linkage-driven systems, leading to a compact mechanical structure that aims to imitate the mobility of a human hand. Based on the investigation of the human hand anatomical structure and the related existing robotic hands, mechanical design of the MCR-hand II is presented. Then, using D-H convention, kinematics of this hand is formulated and illustrated with numerical simulations. Furthermore, fingertip force is deduced and analyzed, and mechatronic system integration and control strategy are addressed. Subsequently, a prototype of the proposed robotic hand is developed, integrated with low-level control system, and following which empirical study is carried out, which demonstrates that the proposed hand is capable of implementing the grasp and manipulation of most of the objects used in daily life. In addition, the three widely used tools, i.e., the Kapandji score test, Cutkosky taxonomy, and Kamakura taxonomy, are used to evaluate the performance of the hand, which evidences that the MCR-hand II possesses high dexterity and excellent grasping capability; object manipulation performance is also demonstrated. This paper hence presents the design and development of a type of novel tendon–linkage-integrated anthropomorphic robotic hand, laying broader background for the development of low-cost robotic hands for both industrial and prosthetic use.
Thermal Energy Discharging Performance of Metal Foam/Paraffin Composite Phase Change Material at Pore Scale
Authors: Yao Yuanpeng , Wu Huiying
Published: January 2021

In this research, thermal energy discharging performance of metal foam/paraffin composite phase change material (MFPC) is investigated at pore scale through direct simulation. A thermal transport model is first developed for heat discharging of MFPC by incorporating the involved effects of solidification phase transition, foam structure, and paraffin volume shrinkage. With this model, the detailed phase interface evolutions, temperature fields, and heat flux distributions of MFPC are numerically obtained and analyzed. It is found that once phase change heat discharging of MFPC begins, the solidification front of paraffin quickly forms and extends along the foam skeleton, which results in remarkably extended thermal transport interface to release latent heat as well as improved spatial synergy in phase change. The effect of local thermal nonequilibrium between porous metal foam and paraffin proves to be intrinsic and significant, providing an efficient inner driving force for enhancing latent heat discharging within MFPC. The overall energy discharging performance of MFPC unit is remarkably improved as compared with pure paraffin unit, evidenced by a large enhancement in latent heat release rate (more than three times) with only small reduction (2.6%) in heat capacity. Simultaneously, it is found that the paraffin-air interface for MFPC unit descends much faster than that for pure paraffin unit due to accelerated volume shrinkage of solidified paraffin within metal foam, resulting in a threefold enhancement in thermally driven dynamic response rate. This study can help more deeply understanding the energy discharging performance of MFPC and providing fundamental guidance for its application in miniaturized thermal systems.
Topological pumping of a 1D dipolar gas into strongly correlated prethermal states
Authors: Kao Wil , Li Kuan-Yu , Lin Kuan-Yu , Gopalakrishnan Sarang , Lev Benjamin L.
Published: January 2021

Making a quantum pump

Most nonequilibrium, many-particle systems eventually reach a thermal state. However, some one-dimensional quantum systems do not thermalize, although they may settle into a long-term equilibrium state. Kao
et al.
studied such a system consisting of dipolar dysprosium atoms confined in an optical potential shaped like a two-dimensional array of elongated tubes. The authors cycled the contact interaction between the atoms in a prescribed way, creating increasingly excited nonthermal quantum many-body states.

Science
, this issue p.
296
Local convergence of behavior across species
Authors: Barsbai Toman , Lukas Dieter , Pondorfer Andreas
Published: January 2021

Not so different

Humans often focus on how different we are from other animals. Certainly, there are some important differences, but more and more we are learning that we differ by degree rather than kind. We see these similarities most clearly when we look at human populations that live a more traditional, foraging lifestyle. Barsbai
et al.
compared more than 300 such foraging human populations with mammal and bird species living in the same environment across a wide array of environmental conditions (see the Perspective by Hill and Boyd). They found that all three groups converged with regard to foraging, social, and reproductive behaviors. Thus, adaptation to environmental selection shapes similar responses across a wide diversity of life forms.

Science
, this issue p.
292
; see also p.
235
Cryo-EM structure of the B cell co-receptor CD19 bound to the tetraspanin CD81
Authors: Susa Katherine J. , Rawson Shaun , Kruse Andrew C. , Blacklow Stephen C.
Published: January 2021

A key complex in B cell activation

A core component of the immune system are B cells, which are activated by infection and then mature to provide long-lived immunity. Activation is initiated when a cell surface B cell receptor, in association with its coreceptor, recognizes an antigen. Susa
et al.
report a structure of the B cell coreceptor signaling subunit CD19 in complex with CD81, a key regulator. CD81 alone binds to cholesterol, but the conformational changes associated with binding to CD19 occlude the cholesterol-binding pocket. Regulating cholesterol binding could play a role in the activation mechanism. The structure also provides a basis for the design of immunotherapies.

Science
, this issue p.
300
Bioactive lipids in antiviral immunity
Authors: Theken Katherine N. , FitzGerald Garret A.
Published: January 2021

Lipids may influence viral entry, replication, and clearance and modulate immune responses
Behavioral convergence in humans and animals
Authors: Hill Kim , Boyd Robert
Published: January 2021

Local ecology combines with culture to produce behavioral variation in hunter-gatherers
GRK2 Mediates β-Arrestin Interactions with 5-HT
2
Receptors for JC Polyomavirus Endocytosis
Authors: Mayberry Colleen L. , Wilczek Michael P. , Fong Tristan M. , Nichols Sarah L. , Maginnis Melissa S.
Published: January 2021

As intracellular parasites, viruses require a host cell to replicate and cause disease. Therefore, virus-host interactions contribute to viral pathogenesis.
The Immunological Impact of Adenovirus Early Genes on Vaccine-Induced Responses in Mice and Nonhuman Primates
Authors: Sangare Kotou , Tuero Iskra , Rahman Mohammad Arif , Hoang Tanya , Miller-Novak Leia K. , Vargas-Inchaustegui Diego A. , Venzon David J. , LaBranche Celia , Montefiori David C. , Robert-Guroff Marjorie , Thomas Michael A.
Published: January 2021

Adenovirus (Ad) is being explored for use in the prevention and treatment of a variety of infectious diseases and cancers. Here, we provide evidence in cells, mice, and nonhuman primates supporting the notion that Ad early gene products limit specific immune responses.