bluuebunny/crossref_metadata_2025 huggingface dataset:
Richard J. Hobbs: how one ecologist has influenced the way we think about restoration ecology
Authors: Valentine Leonie E. , Shackelford Nancy , Johnson Bridget A. , Craig Michael D. , Perring Michael P. , Hulvey Kristin B. , Hallett Lauren M. , Campbell Rebecca , Dudney Joan , Erickson Todd E. , Ritchie Alison , Harrop‐Archibald Hilary , Ramalho Cristina E. , Standish Rachel J.
Published: May 2020

Professor Richard Hobbs has had a profound influence on the development of the discipline of restoration ecology. With more than 300 publications spanning a broad scope of applied ecological sciences, he has collaborated with hundreds of researchers. His sometimes‐provocative insights, balanced by extensive empirical research, will have a lasting impact by encouraging people to think more broadly about the science and practice of ecological restoration. Here, on the eve of his retirement, some of his staff and students, past and present, take a retrospective look at his contributions to restoration ecology both as a scientist and as a mentor.
Foundational Challenges for Advancing the Field and Discipline of Risk Analysis
Authors: Aven Terje , Flage Roger
Published: May 2020

Risk analysis as a field and discipline is about concepts, principles, approaches, methods, and models for understanding, assessing, communicating, managing, and governing risk. The foundation of this field and discipline has been subject to continuous discussion since its origin some 40 years ago with the establishment of the Society for Risk Analysis and the Risk Analysis journal. This article provides a perspective on critical foundational challenges that this field and discipline faces today, for risk analysis to develop and have societal impact. Topics discussed include fundamental questions important for defining the risk field, discipline, and science; the multidisciplinary and interdisciplinary features of risk analysis; the interactions and dependencies with other sciences; terminology and fundamental principles; and current developments and trends, such as the use of artificial intelligence.
Model-based Clustering and Analysis of Life History Data
Authors: Scott Marc A. , Mohan Kaushik , Gauthier Jacques-Antoine
Published: May 2020

Methods and models for longitudinal data with categorical, multi-dimensional outcomes are quite limited, but they are essential to the study of life histories. For example, in the Swiss Household Panel, information on the co-residence and professional status of several thousand individuals is available through to age 45 years. Interest centres on the time and order of life course events such as having children and working full or part time and the duration of the phases that they delineate. With data of this type, optimal matching and clustering algorithms relying on a distance metric or parametric models of duration in a competing risks framework are used; the appropriateness of each derives from competing goals and orientation. We prefer model-based approaches when certain goals are paramount: simulation of individual trajectories; adjusting for time-dependent covariates; handling multistate trajectories and missing outcomes. Several of these goals are particularly challenging when the number of states is of moderate size, and many transitions are infrequent and/or time inhomogeneous. Using the Swiss Household Panel, we demonstrate the appropriateness of latent class growth curve models for analysing sequence data. In particular, models including heterogeneous dependence structure provide new techniques for assessing goodness of fit as well as yield insights into social processes.
Causal Mechanism of Extreme River Discharges in the Upper Danube Basin Network
Authors: Mhalla Linda , Chavez-Demoulin Valérie , Dupuis Debbie J.
Published: May 2020

Extreme hydrological events in the Danube river basin may severely impact human populations, aquatic organisms and economic activity. One often characterizes the joint structure of extreme events by using the theory of multivariate and spatial extremes and its asymptotically justified models. There is interest, however, in cascading extreme events and whether one event causes another. We argue that an improved understanding of the mechanism underlying severe events is achieved by combining extreme value modelling and causal discovery. We construct a causal inference method relying on the notion of the Kolmogorov complexity of extreme conditional quantiles. Tail quantities are derived by using multivariate extreme value models, and causal-induced asymmetries in the data are explored through the minimum description length principle. Our method CausEV for causality for extreme values uncovers causal relationships between summer extreme river discharges in the upper Danube basin and finds significant causal links between the Danube and its Alpine tributary Lech.
SARS‐CoV‐2 infection‐induced immune responses: Friends or foes?
Authors: Li Keying , Hao Zhenhua , Zhao Xiaohui , Du Jiying , Zhou Yanlin
Published: May 2020

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is an emerging coronavirus that belongs to the β‐genus, causing the outbreak of coronavirus disease 19 (COVID‐19). SARS‐CoV‐2 infection can stimulate a pronounced immune response in the host, which embodies in the decrease of lymphocytes and aberrant increase of cytokines in COVID‐19 patients. SARS‐CoV‐2 RNA and proteins interact with various pattern recognition receptors that switch on antiviral immune responses to regulate viral replication and spreading within the host in vivo. However, overactive and impaired immune responses also cause immune damage and subsequent tissue inflammation. This article focuses on the dual roles of immune system during SARS‐CoV‐2 infection, providing a theoretical basic for identifying therapeutic targets in a situation with an unfavourable immune reaction.
Diarrhoeal children with concurrent severe wasting and stunting compared to severe wasting or severe stunting
Authors: Nuzhat Sharika , Shahunja K. M. , Shahid Abu S. M. S. B. , Khan Soroar Hossain , Islam Shoeb Bin , Islam Md. Ridwan , Ahmed Tahmeed , Chisti Mohammod Jobayer , Hossain Md Iqbal , Faruque A. S. G.
Published: May 2020

Objective

Children with both severe wasting and severe stunting (SWSS) represent an extreme form of malnutrition and are prone to develop severe infection. The study aims to demonstrate clinical features and aetiology of diarrhoea among children with SWSS compared to those with either severe wasting (SW) or severe stunting (SS), which may help in early identification of high‐risk children.

Methods

Data were extracted from the database of the diarrhoeal disease surveillance system (DDSS) of Dhaka Hospital, icddr,b from 2008 to 2017. Among 14 403 under‐five diarrhoeal children, 149 had concurrent SWSS (WLZ/WHZ ˂‐3 with LAZ/HAZ ˂‐3), 795 had SW (WLZ/WHZ ˂‐3 but LAZ/HAZ ≥‐3) alone, and 1000 had only SS (LAZ/HAZ ˂‐3 but WLZ/WHZ ≥‐3).

Results

In logistic regression analysis after adjusting for potential confounders, dehydrating diarrhoea and slum dwelling were independently associated with SWSS vs. SW (P < 0.05). When compared with SS, dehydration and maternal illiteracy were independently associated with SWSS (P < 0.05). In comparison with SW or SS, SWSS less often included infection with rotavirus (P < 0.05). Dehydration was independently associated with SW vs. SS after adjusting for potential confounders (P < 0.05).

Conclusion

Children with SWSS more often presented with dehydrating diarrhoea (69%) than children who had either SW (55%) or SS (43%). However, SWSS patients less frequently presented with rotavirus‐associated diarrhoeal illnesses. This result underscores the importance of early detection and prompt management of dehydrating diarrhoea in children with concomitant severe wasting and severe stunting to reduce morbidity and mortality in these children, especially in poor settings.
Systematic analysis of 1298 RNA‐Seq samples and construction of a comprehensive soybean (Glycine max) expression atlas
Authors: Machado Fabricio B. , Moharana Kanhu C. , Almeida‐Silva Fabricio , Gazara Rajesh K. , Pedrosa‐Silva Francisnei , Coelho Fernanda S. , Grativol Clícia , Venancio Thiago M.
Published: May 2020

Soybean (Glycine max[L.] Merr.) is a major crop in animal feed and human nutrition, mainly for its rich protein and oil contents. The remarkable rise in soybean transcriptome studies over the past 5 years generated an enormous amount of RNA‐seq data, encompassing various tissues, developmental conditions and genotypes. In this study, we have collected data from 1298 publicly available soybean transcriptome samples, processed the raw sequencing reads and mapped them to the soybean reference genome in a systematic fashion. We found that 94% of the annotated genes (52 737/56 044) had detectable expression in at least one sample. Unsupervised clustering revealed three major groups, comprising samples from aerial, underground and seed/seed‐related parts. We found 452 genes with uniform and constant expression levels, supporting their roles as housekeeping genes. On the other hand, 1349 genes showed heavily biased expression patterns towards particular tissues. A transcript‐level analysis revealed that 95% (70 963 of 74 490) of the assembled transcripts have intron chains exactly matching those from known transcripts, whereas 3256 assembled transcripts represent potentially novel splicing isoforms. The dataset compiled here constitute a new resource for the community, which can be downloaded or accessed through a user‐friendly web interface athttp://venanciogroup.uenf.br/resources/. This comprehensive transcriptome atlas will likely accelerate research on soybean genetics and genomics.
Metabolomics analysis reveals differences in evolution between maize and rice
Authors: Deng Min , Zhang Xuehai , Luo Jingyun , Liu Haijun , Wen Weiwei , Luo Hongbing , Yan Jianbing , Xiao Yingjie
Published: May 2020

Metabolites are the intermediate and final products of metabolism, which play essential roles in plant growth, evolution and adaptation to changing climates. However, it is unclear how evolution contributes to metabolic variation in plants. Here, we investigated the metabolomics data from leaf and seed tissues in maize and rice. Using principal components analysis based on leaf metabolites but not seed metabolites, metabolomics data could be clearly separated for rice Indica and Japonica accessions, while two maize subgroups, temperate and tropical, showed more visible admixture. Rice and maize seed exhibited significant interspecific differences in metabolic variation, while within rice, leaf and seed displayed similar metabolic variations. Among 10 metabolic categories, flavonoids had higher variation in maize than rice, indicating flavonoids are a key constituent of interspecific metabolic divergence. Interestingly, metabolic regulation was also found to be reshaped dramatically from positive to negative correlations, indicative of the differential evolutionary processes in maize and rice. Moreover, perhaps due to this divergence significantly more metabolic interactions were identified in rice than maize. Furthermore, in rice, the leaf was found to harbor much more intense metabolic interactions than the seed. Our result suggests that metabolomes are valuable for tracking evolutionary history, thereby complementing and extending genomic insights concerning which features are responsible for interspecific differentiation in maize and rice.
Expansion of hospital‐based blood collections in the face of COVID‐19 associated national blood shortage
Authors: Gniadek Thomas J. , Mallek Jessica , Wright Gregory , Saporito Catherine , AbiMansour Nasri , Tangazi Wilkister , Rogers Gloria , Zahara Zachary , Cummings Gabrielle , Kaul Karen , Kang Jason
Published: May 2020

BACKGROUND

When the coronavirus pandemic caused widespread school and business closures in March 2020, blood drives were canceled and the supply of blood decreased suddenly in the United States (US). In response, hospital‐based transfusion medicine physicians instituted policies to conserve blood and decrease blood product usage. These efforts were aided by the US Surgeon General recommendation to cancel all elective procedures. Nevertheless, the duration, severity, and impact of the pandemic on the national blood supply was uncertain. Hospitals with in‐house donor programs had the opportunity not only to control demand, but also increase supply.

STUDY DESIGN AND METHODS

A hospital‐based blood donor center was rapidly mobilized to increase the supply of in‐house collected blood, in order to counteract a sudden but potentially long‐term depletion of the national blood supply during a pandemic.

RESULTS

Collections increased approximately five‐fold above baseline for whole blood units, while apheresis platelet units were maintained at the historical average for the blood donor center. Cancellation of elective procedures showed a modest, but not yet statistically significant decrease in average blood product usage per day, nevertheless the in‐house collection rate was sufficient to meet demand.

CONCLUSION

A hospital‐based blood donor center can quickly increase collection volumes and capacity in the face of a national emergency or pandemic. The desire to collect units should be balanced with safety concerns, need for sustainability, and blood product demand.
Comparison of operation of spinal locomotor networks activated by supraspinal commands and by epidural stimulation of the spinal cord in cats
Authors: Musienko Pavel E. , Lyalka Vladimir F. , Gorskii Oleg V. , Merkulyeva Natalia , Gerasimenko Yuri P. , Deliagina Tatiana G. , Zelenin Pavel V.
Published: May 2020

Key points

Epidural electrical stimulation (ES) of the spinal cord restores/improves locomotion in patients. ES‐evoked locomotor movements differ to some extent from the normal ones. Operation of the locomotor network during ES is unknown.

We compared the activity of individual spinal neurons during locomotion initiated by signals from the brainstem and by ES.

We demonstrated that the spinal network generating locomotion under each of the two conditions is formed by the same neurons.

A part of this network operates similarly under the two conditions, suggesting that it is essential for generation of locomotion under both conditions.

Another part of this network operates differently under the two conditions, suggesting that it is responsible for differences in the movement kinematics observed under the two conditions.

Locomotion is a vital motor function for both animals and humans. Epidural electrical stimulation (ES) of the spinal cord is used to restore/improve locomotor movements in patients. However, operation of locomotor networks during ES has never been studied. Here we compared the activity of individual spinal neurons recorded in decerebrate cats of either sex during locomotion initiated by supraspinal commands (caused by stimulation of the mesencephalic locomotor region, MLR) and by ES. We found that under both conditions, the same neurons had modulation of their activity related to the locomotor rhythm, suggesting that the network generating locomotion under the two conditions is formed by the same neurons. About 40% of these neurons had stable modulation (i.e. small dispersion of their activity phase in sequential cycles), as well as a similar phase and shape of activity burst in MLR‐ and ES‐evoked locomotor cycles. We suggest that these neurons form a part of the locomotor network that operates similarly under the two conditions, and are critical for generation of locomotion. About 23% of the modulated neurons had stable modulation only during MLR‐evoked locomotion. We suggest that these neurons are responsible for some differences in kinematics of MLR‐ and ES‐evoked locomotor movements. Finally, 25% of the modulated neurons had unstable modulation during both MLR‐ and ES‐evoked locomotion. One can assume that these neurons contribute to maintenance of the excitability level of locomotor networks necessary for generation of stepping, or belong to postural networks, activated simultaneously with locomotor networks by both MLR stimulation and ES.
Transcapillary PO2 gradients in contracting muscles across the fibre type and oxidative continuum
Authors: Colburn Trenton D. , Hirai Daniel M. , Craig Jesse C. , Ferguson Scott K. , Weber Ramona E. , Schulze Kiana M. , Behnke Brad J. , Musch Timothy I. , Poole David C.
Published: May 2020

Key points

Within skeletal muscle the greatest resistance to oxygen transport is thought to reside across the short distance at the red blood cell–myocyte interface. These structures generate a significant transmural oxygen pressure (PO2) gradient in mixed fibre‐type muscle.

Increasing O2 flux across the capillary wall during exercise depends on: (i) the transmural O2 pressure gradient, which is maintained in mixed‐fibre muscle, and/or (ii) elevating diffusing properties between microvascular and interstitial compartments resulting, in part, from microvascular haemodynamics and red blood cell distribution.

We evaluated the PO2 within the microvascular and interstitial spaces of muscles spanning the slow‐ to fast‐twitch fibre and high‐ to low‐oxidative capacity spectrums, at rest and during contractions, to assess the magnitude of transcapillary PO2 gradients in rats.

Our findings demonstrate that, across the metabolic rest–contraction transition, the transcapillary pressure gradient for O2 flux is: (i) maintained in all muscle types, and (ii) the lowest in contracting highly oxidative fast‐twitch muscle.

In mixed fibre‐type skeletal muscle transcapillary PO2 gradients (PO2mv‐PO2is; microvascular and interstitial, respectively) drive O2 flux across the blood–myocyte interface where the greatest resistance to that O2 flux resides. We assessed a broad spectrum of fibre‐type and oxidative‐capacity rat muscles across the rest‐to‐contraction (1 Hz, 120 s) transient to test the novel hypotheses that: (i) slow‐twitch PO2is would be greater than fast‐twitch, (ii) muscles with greater oxidative capacity have greater PO2is than glycolytic counterparts, and (iii) whether PO2mv‐PO2is at rest is maintained during contractions across all muscle types. PO2mv and PO2is were determined via phosphorescence quenching in soleus (SOL; 91% type I+IIa fibres and CSa: ∼21 μmol min‐1 g‐1), peroneal (PER; 33% and ∼20 μmol min‐1 g‐1), mixed (MG; 9% and ∼26 μmol min‐1 g‐1) and white gastrocnemius (WG; 0% and ∼8 μmol min‐1 g‐1) across the rest–contraction transient. PO2mv was higher than PO2is in each muscle (∼6–13 mmHg; P < 0.05). SOL PO2isarea was greater than in the fast‐twitch muscles during contractions (P < 0.05). Oxidative muscles had greater PO2isnadir (9.4 ± 0.8, 7.4 ± 0.9 and 6.4 ± 0.4; SOL, PER and MG, respectively) than WG (3.0 ± 0.3 mmHg, P < 0.05). The magnitude of PO2mv‐PO2is at rest decreased during contractions in MG only (∼11 to 7 mmHg; time × (PO2mv‐PO2is) interaction, P < 0.05). These data support the hypothesis that, since transcapillary PO2 gradients during contractions are maintained in all muscle types, increased O2 flux must occur via enhanced intracapillary diffusing conductance, which is most extreme in highly oxidative fast‐twitch muscle.
Blood viscosity and its determinants in the highest city in the world
Authors: Stauffer Emeric , Loyrion Emmanuelle , Hancco Ivan , Waltz Xavier , Ulliel‐Roche Mathilde , Oberholzer Laura , Robach Paul , Pichon Aurélien , Brugniaux Julien V. , Bouzat Pierre , Doutreleau Stéphane , Connes Philippe , Verges Samuel
Published: May 2020

Key points

Highlanders develop unique adaptative mechanisms to chronic hypoxic exposure, including substantial haemoglobin and haematocrit increases.

However, a significant proportion of populations living permanently at high altitude develop maladaptive features known as chronic mountain sickness (CMS).

This study aimed to assess the effects of permanent life at high altitude on clinical and haemorheological parameters (blood viscosity and red blood cell aggregation) and to compare clinical and haemorheological parameters of dwellers from the highest city in the world according to CMS severity.

Blood viscosity increased with altitude, together with haemoglobin concentration and haematocrit. At 5100 m, highlanders with moderate‐to‐severe CMS had higher blood viscosity mainly at high shear rate and even at corrected haematocrit (40%), with a lower red blood cell aggregation.

Blood viscosity may contribute to CMS symptomatology but the increased blood viscosity in CMS patients cannot solely be explained by the rise in haematocrit.

Chronic mountain sickness (CMS) is a condition characterised by excessive erythrocytosis (EE). While EE is thought to increase blood viscosity and subsequently to trigger CMS symptoms, the exact relationship between blood viscosity and CMS symptoms remains incompletely understood. We assessed the effect of living at high altitude on haemoglobin, haematocrit and haemorheological parameters (blood viscosity and red blood cell aggregation), and investigated their relationship with CMS in highlanders living in the highest city in the world (La Rinconada, Peru, 5100 m). Ninety‐three men participated in this study: 10 Caucasian lowlanders, 13 Andean highlanders living at 3800 m and 70 Andean highlanders living at 5100 m (35 asymptomatic, CMS score ≤5; 15 with mild CMS, CMS score between 6 and 10; 20 with moderate‐to‐severe CMS, CMS score >10). Blood viscosity was measured at native and corrected haematocrit (40%). Haemoglobin concentration and haematocrit increased with the altitude of residency. Blood viscosity also increased with altitude (at 45 s−1: 6.7 ± 0.9 mPa s at sea level, 14.0 ± 2.0 mPa s at 3800 m and 27.1 ± 8.8 mPa s at 5100 m; P < 0.001). At 5100 m, blood viscosity at corrected haematocrit was higher in highlanders with moderate‐to‐severe CMS (at 45 s−1: 18.9 ± 10.7 mPa s) than in highlanders without CMS (10.2 ± 5.9 mPa s) or with mild CMS (12.1 ± 6.1 mPa s) (P < 0.05). In conclusion, blood viscosity may contribute to CMS symptomatology but the increased blood viscosity in CMS patients cannot solely be explained by the rise in haematocrit.
The startle disease mutation α1S270T predicts shortening of glycinergic synaptic currents
Authors: Wu Zhiyi , Lape Remigijus , Jopp‐Saile Lea , O'Callaghan Benjamin J. , Greiner Timo , Sivilotti Lucia G.
Published: May 2020

Key points

Loss‐of‐function mutations in proteins found at glycinergic synapses, most commonly in the α1 subunit of the glycine receptor (GlyR), cause the startle disease/hyperekplexia channelopathy in man.

It was recently proposed that the receptors responsible are presynaptic homomeric GlyRs, rather than postsynaptic heteromeric GlyRs (which mediate glycinergic synaptic transmission), because heteromeric GlyRs are less affected by many startle mutations than homomers.

We examined the α1 startle mutation S270T, at the extracellular end of the M2 transmembrane helix.

Recombinant heteromeric GlyRs were less impaired than homomers by this mutation when we measured their response to equilibrium applications of glycine.

However, currents elicited by synaptic‐like millisecond applications of glycine to outside‐out patches were much shorter (7‐ to 10‐fold) in all mutant receptors, both homomeric and heteromeric. Thus, the synaptic function of heteromeric receptors is likely to be impaired by the mutation.

Human startle disease is caused by mutations in glycine receptor (GlyR) subunits or in other proteins associated with glycinergic synapses. Many startle mutations are known, but it is hard to correlate the degree of impairment at molecular level with the severity of symptoms in patients. It was recently proposed that the disease is caused by disruption in the function of presynaptic homomeric GlyRs (rather than postsynaptic heteromeric GlyRs), because homomeric GlyRs are more sensitive to loss‐of‐function mutations than heteromers. Our patch‐clamp recordings from heterologously expressed GlyRs characterised in detail the functional consequences of the α1S270T startle mutation, which is located at the extracellular end of the pore lining M2 transmembrane segment (18ʹ). This mutation profoundly decreased the maximum single‐channel open probability of homomeric GlyRs (to 0.16; cf. 0.99 for wild type) but reduced only marginally that of heteromeric GlyRs (0.96; cf. 0.99 for wild type). However, both heteromeric and homomeric mutant GlyRs became less sensitive to the neurotransmitter glycine. Responses evoked by brief, quasi‐synaptic pulses of glycine onto outside‐out patches were impaired in mutant receptors, as deactivation was approximately 10‐ and 7‐fold faster for homomeric and heteromeric GlyRs, respectively. Our data suggest that the α1S270T mutation is likely to affect the opening step in GlyR activation. The faster decay of synaptic currents mediated by mutant heteromeric GlyRs is expected to reduce charge transfer at the synapse, despite the high equilibrium open probability of these mutant channels.
Numerical Study on Effect of Thermal Conductivity in Point Contacts With Longitudinal Roughness on Abnormal Pressure Distribution
Authors: Kaneta Motohiro , Matsuda Kenji , Wang Jing , Yang Peiran
Published: May 2020

In order to clarify the effect of thermal conductivity on non-Newtonian thermal elastohydrodynamic lubrication (EHL) in the point contact with longitudinal roughness on one surface or on both surfaces, numerical calculations are carried out. The contact is formed by ceramics and steel. The surface shapes of both contact solids are investigated separately. It was found that the pressure at ridges shows lower than that at grooves when the speed of a material with low thermal conductivity is faster than that of a material with high thermal conductivity. In the opposite case, such a phenomenon never occurs. This abnormal pressure variation is largely affected by the combination of contact materials and running conditions.
Controllable Solar Flux Heating for Freeze Recovery in Molten Salt Parabolic Trough Collectors
Authors: Imponenti Luca , Shininger Ryan , Gawlik Keith , Price Hank , Zhu Guangdong
Published: May 2020

In molten-salt parabolic trough plants, the melting process is particularly important for freeze recovery of salt that is solidified in a collector loop, should such an event occur. Currently impedance heating is expected for freeze recovery of the collector loops, but this method can be expensive. A lower-cost alternative is proposed to use controllable concentrated solar flux directly from the parabolic mirrors to thaw salt that is frozen in the collector. A computational fluid dynamics model was developed to explore the solidification and melting processes of molten salt in a parabolic trough receiver and to assess the viability of this concept. Results indicate that concentrated solar heating has the potential to melt frozen salt in 5.6 h, compared to that in 8.8 h for a 300 W m−1 impedance heating system. At the same time, controllable solar flux heating introduces nonuniform solar fluxes on the receiver surface, which can induce significant thermal stress on the receiver tube. A preliminary stress analysis indicates that the temperature difference across the receiver tube should be maintained below about 70 °C for heating up to 300 °C at internal pressures ≤10 bar. At these conditions, freeze recovery using solar flux heating will not significantly affect receiver lifetime. These results suggest that controllable solar flux heating could effectively supplement or replace impedance heating in the freeze recovery system. Incorporating this methodology in future parabolic trough concentrating solar power plants is an opportunity for capital and operational cost-savings.
Thermoeconomic Analysis of a Combined Natural Gas Cogeneration System With a Supercritical CO2 Brayton Cycle and an Organic Rankine Cycle
Authors: Pan Zhen , Yan Mingyue , Shang Liyan , Li Ping , Zhang Li , Liu Jiaqi
Published: May 2020

This paper proposes a new type of Gas Turbine Cycle-supercritical CO2 Brayton/organic Rankine cycle (GT-SCO2/ORC) cogeneration system, in which the exhaust gas from gas-fired plants generates electricity through GT and then the remaining heat is absorbed by the supercritical CO2 (SCO2) Brayton cycle and ORC. CO2 contained in the exhaust gas is absorbed by monoethanolamine (MEA) and liquefied via liquified natural gas (LNG). Introducing thermodynamic efficiencies, thermoeconomic analysis to evaluate the system performance and total system cost is used as the evaluation parameter. The results show that the energy efficiency and exergy efficiency of the system are 56.47% and 45.46%, respectively, and the total cost of the product is 2798.38 $/h. Moreover, with the increase in air compressor (AC) or gas turbine isentropic efficiency, GT inlet temperature, and air preheater (AP) outlet temperature, the thermodynamic efficiencies have upward trends, which proves these four parameters optimize the thermodynamic performance. The total system cost can reach a minimum value with the increase in AC pressure ratio, GT isentropic efficiency, and AC isentropic efficiency, indicating that these three parameters can optimize the economic performance of the cycle. The hot water income increases significantly with the increase in the GT inlet temperature, but it is not cost-effective in terms of the total cost.
Split Injection Strategies for Biodiesel-Fueled Premixed Charge Compression Ignition Combustion Engine—Part II: Particulate Studies
Authors: Singh Akhilendra Pratap , Agarwal Avinash Kumar
Published: May 2020

In this study, experiments were performed in a single-cylinder research engine to investigate the particulate matter (PM) characteristics of the engine operated in premixed charge compression ignition (PCCI) mode combustion vis-a-vis baseline compression ignition (CI) mode combustion using three test fuels, namely, B20 (20% v/v biodiesel blended with mineral diesel), B40 (40% v/v/ biodiesel blended with mineral diesel), and baseline mineral diesel. The experiments were carried out at constant fuel injection pressure (FIP) (700 bar), constant engine speed (1500 rpm), and constant fuel energy input (0.7 kg/h diesel equivalent). PM characteristics of PCCI mode combustion were evaluated using two different fuel injection strategies, namely, single pilot injection (SPI) (35 deg before top dead center (bTDC)) and double pilot injection (DPI) (35 deg and 45 deg bTDC) at four different start of main injection (SoMI) timings. Results showed that both PCCI mode combustion strategies emitted significantly lower PM compared to baseline CI mode combustion strategy. However, the blending of biodiesel resulted in relatively higher PM emissions from both CI and PCCI combustion modes. Chemical characterization of PM showed that PCCI mode combustion emitted relatively lower trace metals compared to baseline CI mode combustion, which reduced further for B20. For detailed investigations of particulate structure, morphological characterization was done using transmission electron microscopy (TEM), which showed that PM emitted by B20-fueled PCCI mode combustion posed potentially lower health risk compared to baseline mineral diesel-fueled CI mode combustion.
SLIPS-LAB—A bioinspired bioanalysis system for metabolic evaluation of urinary stone disease
Authors: Li Hui , Shkolyar Eugene , Wang Jing , Conti Simon , Pao Alan C. , Liao Joseph C. , Wong Tak-Sing , Wong Pak Kin
Published: May 2020

A bioinspired system enables rapid, near-patient urine testing for metabolic evaluation of stone formers.
Global Regulator of Rubber Degradation in Gordonia polyisoprenivorans VH2: Identification and Involvement in the Regulation Network
Authors: de Witt Jan , Oetermann Sylvia , Parise Mariana , Parise Doglas , Baumbach Jan , Steinbüchel Alexander
Published: May 2020

In order to develop efficient microbial recycling strategies for rubber waste materials, it is required that we understand the degradation pathway of the polymer and how it is regulated. However, only little is known about the transcriptional regulation of the rubber degradation pathway, which seems to be upregulated in the presence of the polymer. We identified a novel key regulator of rubber degradation (CRP
VH2
) that regulates several parts of the pathway in the potent rubber-degrader
G. polyisoprenivorans
VH2. Furthermore, we provide evidence for a widespread involvement of CRP regulators in the degradation of rubber in various other rubber-degrading actinomycetes. Thus, these novel insights into the regulation of rubber degradation are essential for developing efficient microbial degradation strategies for rubber waste materials by this group of actinomycetes.
Petrogenesis of the crystalline basement along the western Gulf of Mexico: Postcollisional magmatism during the formation of Pangea
Authors: Coombs Henry E. , Kerr Andrew C. , Pindell James , Buchs David , Weber Bodo , Solari Luigi
Published: May 2020

The supercontinent of Pangea formed through the diachronous collision of Laurussia and Gondwana during the late Paleozoic. While magmatism associated with its formation is well documented in the Variscan orogeny of Europe and Alleghanian orogeny of the United States, little is known about the Sonora orogeny of northern Mexico. This paper reports geochronology (U-Pb zircon), whole-rock geochemistry, and Lu-Hf zircon isotope data on basement cores from the western Gulf of Mexico, which were used to develop a tectonomagmatic model for pre- to post-Pangea amalgamation. Our results suggest the existence of three distinct phases of magmatism, produced during different stages of continental assembly and disassembly. The first phase consists of Early Permian (294–274 Ma; n = 3) granitoids with geochemical signatures indicative of a continental arc tectonic setting. This phase formed on the margins of Gondwana during the closure of the Rheic Ocean, prior to the final amalgamation of Pangea. It likely represents a lateral analogue of late Carboniferous–Early Permian granitoids that intrude the Acatlán and Oaxacan Complexes. The second phase of magmatism includes Late Permian–Early Triassic (263–243 Ma; n = 13) granitoids with suprasubduction geochemical affinities. However, Lu-Hf isotope data indicate that these granitoids formed from crustal anatexis, with εHf values and two-step Hf depleted mantle model ages (TDM[Hf]) comparable to the Oaxaquia continental crust into which they intrude. This phase of magmatism is likely related to coeval granitoids in the Oaxaca area and Chiapas Massif. We interpret it to reflect late- to postcollisional magmatism along the margin of Gondwana following the assembly of Pangea. Finally, the third phase of magmatism includes Early–Middle Jurassic (189–164 Ma; n = 2) mafic porphyries, which could be related to the synchronous suprasubduction magmatism associated with the Nazas arc. Overall, our results are consistent with Pangea assembly through diachronous collision of Laurussia and Gondwana during subduction of the Rheic Ocean. They suggest that postorogenic magmatism in the western termination of the Rheic suture occurred under the influence of a Panthalassan subduction zone, before opening of the Gulf of Mexico.
Thermochronology of the southern Mexican margin (Xolapa belt), Acapulco to Puerto Angel: Crustal dynamics of a trench-trench-transform triple junction
Authors: Villagómez* Diego , Pindell James
Published: May 2020

New low-temperature thermochronological data analyses (apatite fission track and apatite and zircon [U-Th]/He) on rocks from the southern (Pacific) margin of Mexico between Acapulco and the western Gulf of Tehuantepec, where pre–middle Eocene arc and forearc complexes are expected but missing, show that this continental margin was subjected to an important Tertiary exhumational event. Exhumation is constrained to ca. 32–20 Ma in the west (Acapulco) and to ca. 19–11 Ma in the east (Puerto Angel) and was thus eastwardly diachronous. The diachroneity is interpreted as relating to the migration of the Chortis block, representing the western end of the Caribbean plate. The amount of exhumation along the trend is constrained to roughly 4–5 km (~0.3–0.6 km/m.y.). These magnitudes and rates are much less than previous estimates of 2.5–4 km/m.y. during the Oligocene, which are likely overestimated. These faster rates have been employed in a competing model for arc removal by orthogonal subduction erosion (i.e., Chortis block not involved), which is accordingly questioned. The exhumation was not due to shearing or fault-related uplift as the Chortis block migrated, but rather to the inception of subduction along Mexico in the wake of Chortis block migration. A four-part history applies to southern Mexico that is eastwardly diachronous: (1) inception of arc magmatism as the Chortis block first moved over the ~150 km depth contour of the Farallon/Cocos Benioff zone; (2) uplift and exhumation of basement as southern Mexico encountered and overrode the site of the Farallon/Cocos Benioff zone; (3) northward migration of arc magmatism as the Chortis block left the cross section and North America continued to advance further onto the Cocos plate, producing flat slab subduction geometry; and (4) resumption of forearc subsidence once the Mexican margin had acquired a subduction zone hanging-wall geometry. The missing arc terrane along southern Mexico is the Chortis block.
Characteristics of myopic traction maculopathy in myopic Singaporean
adults
Authors: Matsumura Saiko , Sabanayagam Charumathi , Wong Chee Wai , Tan Chuen-Seng , Kuo Anthony , Wong Yee Ling , Ohno-Matsui Kyoko , Wong Tien Yin , Cheng Ching-Yu , Hoang Quan V , Saw Seang Mei
Published: May 2020

Purpose

To investigate the characteristics, risk factors and visual impact of
myopic traction maculopathy (MTM) among adults with myopia in
Singapore.

Methods

We analysed 3316 myopic eyes of adults aged over 40 years who participated
in the Singapore Epidemiology of Eye Diseases-2 study. Detailed questionnaires
and ophthalmic examinations were conducted. A total of 2913 myopic eyes of 1639
subjects were graded for MTM by spectral-domain optical coherence tomography.
MTM is defined as the presence of retinoschisis, lamellar or full-thickness
macula hole and foveal retinal detachment. Fundus photographs were graded for
myopic macular degeneration (MMD).

Results

Of these 2913 myopic eyes, the mean and SD of age was 60.1±8.0 years; the
spherical equivalent (SE) was −2.5±2.3 D; and the axial length (AL) was
24.6±1.3 mm. MTM was found in 0.9% of myopic eyes and 7.3% of highly myopic
eyes. In the multivariate analysis, myopic SE (p<0.001), longer AL
(p<0.001), MMD (p=0.01) and epiretinal traction (p<0.001) were
independent risk factors for MTM. MTM was not associated with age (p=0.38). MTM
was significantly associated with poorer best-corrected visual acuity (BCVA)
(p<0.01).

Conclusions

Our population-based study revealed that MTM was present in 0.9% of myopic
eyes and 7.3% of highly myopic eyes. While greater myopic SE, longer AL, MMD
and epiretinal traction are risk factors of MTM, age was not related to MTM.
MTM has a negative effect on BCVA.
Associations of workflow disruptions in the operating room with surgical outcomes: a systematic review and narrative synthesis
Authors: Koch Amelie , Burns Jacob , Catchpole Ken , Weigl Matthias
Published: May 2020

Background

Performance in the operating room is an important determinant of surgical safety. Flow disruptions (FDs) represent system-related performance problems that affect the efficiency of the surgical team and have been associated with a risk to patient safety. Despite the growing evidence base on FDs, a systematic synthesis has not yet been published.

Objective

Our aim was to identify, evaluate and summarise the evidence on relationships between intraoperative FD events and provider, surgical process and patient outcomes.

Methods

We systematically searched databases MEDLINE, Embase and PsycINFO (last update: September 2019). Two reviewers independently screened the resulting studies at the title/abstract and full text stage in duplicate, and all inconsistencies were resolved through discussion. We assessed the risk of bias of included studies using established and validated tools. We summarised effects from included studies through a narrative synthesis, stratified based on predefined surgical outcome categories, including surgical process, provider and patient outcomes.

Results

We screened a total of 20 481 studies. 38 studies were found to be eligible. Included studies were highly heterogeneous in terms of methodology, medical specialty and context. Across studies, 20.5% of operating time was attributed to FDs. Various other process, patient and provider outcomes were reported. Most studies reported negative or non-significant associations of FDs with surgical outcomes.

Conclusion

Apart from the identified relationship of FDs with procedure duration, the evidence base concerning the impact of FDs on provider, surgical process and patient outcomes is limited and heterogeneous. We further provide recommendations concerning use of methods, relevant outcomes and avenues for future research on associated effects of FDs in surgery.
Full-field optical coherence tomography: novel imaging technique for extemporaneous high-resolution analysis of mucosal architecture in human gut biopsies
Authors: Quénéhervé Lucille , Olivier Raphael , Gora Michalina J , Bossard Céline , Mosnier Jean-François , Benoit a la Guillaume Emilie , Boccara Claude , Brochard Charlène , Neunlist Michel , Coron Emmanuel
Published: May 2020

Full-field optical coherence tomography (FFOCT) is an imaging technique of biological tissue based on tissue light reflectance analysis. We evaluated the feasibility of imaging fresh digestive mucosal biopsies after a quick mounting procedure (5 min) using two distinct modalities of FFOCT. In static FFOCT mode, we gained high-resolution images of general gut tissue-specific architecture, such as oesophageal papillae, gastric pits, duodenal villi and colonic crypts. In dynamic FFOCT mode, we imaged individual epithelial cells of the mucosal lining with a cellular or subcellular resolution and identified cellular components of the lamina propria. FFOCT represents a promising dye-free imaging tool for on-site analysis of gut tissue remodelling.
Early cardiac magnetic resonance imaging in troponin-positive acute chest pain and non-obstructed coronary arteries
Authors: Vágó Hajnalka , Szabó Liliána , Dohy Zsófia , Czimbalmos Csilla , Tóth Attila , Suhai Ferenc Imre , Bárczi György , Gyarmathy V. Anna , Becker Dávid , Merkely Béla
Published: May 2020

Objective

We assessed the diagnostic and prognostic implications of early cardiac magnetic resonance (CMR), CMR-based deformation imaging and conventional risk factors in patients with troponin-positive acute chest pain and non-obstructed coronary arteries.

Methods

In total, 255 patients presenting between 2009 and 2019 with troponin-positive acute chest pain and non-obstructed coronary arteries who underwent CMR in ≤7 days were followed for a clinical endpoint of all-cause mortality. Cine movies, T2-weighted and late gadolinium-enhanced images were evaluated to establish a diagnosis of the underlying heart disease. Further CMR analysis, including left ventricular strain, was carried out.

Results

CMR (performed at a mean of 2.7 days) provided the diagnosis in 86% of patients (54% myocarditis, 22% myocardial infarction (MI) and 10% Takotsubo syndrome and myocardial contusion (n=1)). The 4-year mortality for a diagnosis of MI, myocarditis, Takotsubo and normal CMR patients was 10.2%, 1.6%, 27.3% and 0%, respectively. We found a strong association between CMR diagnosis and mortality (log-rank: 24, p<0.0001). Takotsubo and MI as the diagnosis, age, hypertension, diabetes, female sex, ejection fraction, stroke volume index and most of the investigated strain parameters were univariate predictors of mortality; however, in the multivariate analysis, only hypertension and circumferential mechanical dispersion measured by strain analysis were independent predictors of mortality.

Conclusions

CMR performed in the early phase establishes the proper diagnosis in patients with troponin-positive acute chest pain and non-obstructed coronary arteries and provides additional prognostic factors. This may indicate that CMR could play an additional role in risk stratification in this patient population.
Facilitators and barriers to child restraint use in motor vehicles: a qualitative evidence synthesis
Authors: Bhaumik Soumyadeep , Hunter Kate , Matzopoulos Richard , Prinsloo Megan , Ivers Rebecca Q , Peden Margaret
Published: May 2020

Background

Road traffic collisions contribute a significant burden of mortality and morbidity to children globally. The improper or non-use of child restraints can result in children sustaining significant injuries in the event of a collision. Systematic reviews on the effectiveness of various interventions to increase the use of child restraints already exist but to the best of our knowledge, there has been no qualitative evidence syntheses on the facilitators and barriers to child restraint usage. This review aims to fill that gap.

Methods

We searched for qualitative studies, which focused on perceptions, values and experiences of children, parents/caregivers or any other relevant stakeholders on the use of restraints for children travelling in motor vehicles in PubMed, EMBASE and Global Health and screened reference lists of all included studies. We assessed the quality of included studies with the Critical Appraisal Skills Programme (CASP) checklist and used the PROGRESS Plus lens for an equity focused analysis.

Results

We identified a total of 335 records from searching the databases and five records from other sources. After screening, we identified 17 studies that met our inclusion criteria. All but one study (which had children as participants) focused on the perceptions, attitudes and barriers of parents or caregivers. The included studies were from three high-income (n=14) and one upper-middle income (n=3) country. In addition, although many focused exclusively on participants from culturally and linguistically diverse minorities, the issue of equity was not well addressed. Five major themes emerged from the analysis. (1) perceived risk for injuries and perceived safety benefits of child restraint usage varies in different settings and between different types of caregivers; (2) practical issues around the use of child restraints is a major barrier to its uptake as a child safety measure; (3) restraint use is considered as a mechanism to discipline children rather than as a safety device by parents and as children became older they actively seek opportunities to negotiate the non-usage of restraints; (4) adoption and enforcement of laws shape perceptions and usage in all settings and (5) perceptions and norms of child safety differ among culturally and linguistically diverse groups.

Conclusion

The results of this systematic review should be considered when designing interventions to promote the uptake of child restraints. However, there is a need to conduct qualitative research around the facilitators and barriers to child restraint usage in low-income and middle-income countries. Furthermore, there is a need for more evidence conducted in semiurban and rural areas and to involve fathers, policy-makers, implementers and enforcement agencies in such studies.