bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors determining species richness patterns of breeding birds along an elevational gradient in the Horn of Africa region
Authors: Abebe Ahunim Fenitie , Cai Tianlong , Wale Melaku , Song Gang , Fjeldså Jon , Lei Fumin 
Published: August 2019

AbstractAimTo document the species richness patterns of breeding birds along elevational gradients and explore its drivers in the Horn of Africa region.LocationHorn of Africa region.TaxonBreeding birds.MethodsDistributional data for breeding birds were collected. Elevational distribution data were extracted, interpolated, and assembled for all birds, passerines, and nonpasserines. In order to tease apart how different environmental factors contributed to the variation in species richness, we found it is necessary to divide the area into four subregions with different climatic regimes and topographic structure, namely western slope, eastern slope, wet side, and dry side. Then, the species richness in each 100‐m elevational band was counted along the elevational gradients of each subregion. Pearson's correlation analyses and ordinary least squares (OLS) regressions were used to examine the relationships between species richness and factors.ResultsThe variation in species richness followed hump‐shaped patterns for all subregions, although with peak values at different elevations. The bird species groups on the western and eastern slopes showed low and high plateaus with mid‐elevation peaks, respectively, but very low species diversities at the highest elevations. Species richness was significantly correlated with temperature range and productivity in each subregion. The temperature range, area, and productivity explained 82% of the species richness variations for all birds on the western slope.Main conclusionsThe separate analyses of four area subdivisions provide strong indications of how various factors interact. Productivity and temperature range were the major driving factors for shaping the richness patterns, but deviations from expected patterns suggest modifying roles of mist formation zones in the valleys that deeply intersect the large highlands in the west and rich riparian vegetation where water from cool and humid environments at high elevation reaches lower elevations in the arid east. Conservation is recommended in each subregion based on the elevational richness scenarios.
Fine‐scale hierarchical genetic structure and kinship analysis of the ascidianPyura chilensisin the southeastern Pacific
Authors: Morales‐González Sarai , Giles Emily C. , Quesada‐Calderón Suany , Saenz‐Agudelo Pablo 
Published: August 2019

AbstractStudying population structure and genetic diversity at fine spatial scales is key for a better understanding of demographic processes that influence population connectivity. This is particularly important in marine benthic organisms that rely on larval dispersal to maintain connectivity among populations. Here, we report the results of a genetic survey of the ascidianPyura chilensisfrom three localities along the southeastern Pacific. This study follows up on a previous report that described a genetic break in this region among localities only 20 km apart. By implementing a hierarchical sampling design at four spatial levels and using ten polymorphic microsatellite markers, we test whether differences in fine‐scale population structure explain the previously reported genetic break. We compared genetic spatial autocorrelations, as well as kinship and relatedness distributions within and among localities adjacent to the genetic break. We found no evidence of significant autocorrelation at the scale up to 50 m despite the low dispersal potential ofP. chilensisthat has been reported in the literature. We also found that the proportion of related individuals in close proximity (<1 km) was higher than the proportion of related individuals further apart. These results were consistent in the three localities. Our results suggest that the spatial distribution of related individuals can be nonrandom at small spatial scales and suggests that dispersal might be occasionally limited in this species or that larval cohorts can disperse in the plankton as clustered groups. Overall, this study sheds light on new aspects of the life of this ascidian as well as confirms the presence of a genetic break at 39°S latitude. Also, our data indicate there is not enough evidence to confirm that this genetic break can be explained by differences in fine‐scale genetic patterns among localities.
Intraspecific facilitation explains the persistence of Phragmites australis in modified coastal wetlands
Authors: Reijers Valérie C. , van den Akker Marloes , Cruijsen Peter M. J. M. , Lamers Leon P. M. , van der Heide Tjisse 
Published: August 2019

AbstractCoastal exploitation and human‐mediated modifications have markedly altered the community composition and functioning of coastal wetlands worldwide. Although recent work has shown that harnessing positive density‐dependent feedbacks can greatly enhance the recovery of habitat‐modifying species in degraded wetlands, the role of these intraspecific feedbacks in explaining the persistence of altered, unfavorable plant communities remains largely unexplored. Here, we experimentally tested whether intraspecific facilitation may explain the persistence of common reed (Phragmites australis) in human‐modified coastal wetlands. We performed a full‐factorial mesocosm experiment crossing low‐density pioneer versus high‐density established development stages with saline (20 psu) versus freshwater conditions. Results showed a clear shift in plant growth response from intraspecific competition under freshwater conditions to self‐facilitation in saline treatments. We identified two positive feedback mechanisms enabling the established treatment to overcome salinity stress: (1) Enhanced root oxygenation of the sediment at higher plant density decreased accumulation and intrusion of phytotoxic sulfide, and (2) density‐dependent rainwater infiltration into the soil lowered salinity in the dense root mat, preventing salt stress. Our study demonstrates that intraspecific facilitation can be an important factor in explaining the persistence of Phragmites australis in coastal wetlands. We emphasize the importance of integrating positive interactions in coastal restoration but argue that they should either be harnessed when restoring vegetation or broken when eradication of nontarget species is the management objective.
Response surface optimization of acid pretreatment of cassava stem for bioethanol production
Authors: Sivamani Selvaraju , Baskar Rajoo , Chandrasekaran Arun P. 
Published: August 2019

AbstractAgricultural waste, cassava stem was found to contain about 25 and 40% of hemicellulose and cellulose, respectively. Bioethanol is produced from cassava stem by dilute acid pretreatment followed by alkali delignification, cellulase digestion, and fermentation by Fusarium oxysporum. Dilute acid pretreatment was optimized by response surface methodology based Box–Behnken design. The optimum xylose concentration obtained by the experiment was 11.24 g/L and the model was sulfuric acid concentration of 2.02% (v/v), solid to liquid ratio of 0.05 g/ml and 79 min. After alkali delignification and cellulase hydrolysis of pretreated cassava stem, the glucose content was 18.1 g/L and the bioethanol concentration obtained through co‐fermentation of xylose and glucose by F. oxysporum was 13.62 g/L. The optimum values indicated that 91.1% yield was achieved with cassava stem using dilute sulfuric acid pretreatment. Hence, the dilute acid pretreatment of cassava stem was found to be the promising method for bioethanol production.
Numerical and experimental study of a novel aerodynamic foam breaker for foam drilling fluid
Authors: Cao Pinlu , Chen Zhuo , Liu Miaomiao , Cao Hongyu , Chen Baoyi 
Published: August 2019

AbstractDefoaming is a key technology for increasing the efficiency of foam drilling in petroleum engineering. To enhance the performance of a mechanical foam breaker in foam drilling, a novel aerodynamic foam breaker with two annular slits was investigated in this study. The computational fluid dynamics code of ANSYS Fluent was used to simulate the velocity and pressure distribution inside the foam breaker, and the optimum distance between the two annular slits was determined based on the simulation methods. Meanwhile, a series of experiments were conducted to test the actual performance of the foam breaker. The results demonstrate that various factors may affect the efficiency of the foam breaker, including the foam gas‐liquid ratio, basic liquid viscosity, and air supply method. A higher gas‐liquid ratio of the foam and air supply pressure result in a superior foam breaker performance. The viscosity of the foam liquid phase exhibits exactly the opposite behavior, meaning that the foam breaker more effectively destroys foam from a lower‐viscosity liquid. This study verifies the practicability of this novel aerodynamic foam breaker and discusses the effects of different parameters on the defoaming percentage, and this study can act as a reference and guidance for subsequent defoaming research.
An integrated heat recovery and storage system for a residential building
Authors: Bolt Andre A , Dincer Ibrahim , Agelin‐Chaab Martin 
Published: August 2019

AbstractIn this article, a novel multigeneration system is proposed which can produce four useful outputs for a small residential building located in Ottawa, Ontario (Canada). The residential building has a total of six floors, 24 units, and houses ~96 residents. The system uses parabolic solar collectors to superheat steam, which then provides energy to the remainder of the cycle. During the nighttime or poor weather conditions, the system can still function effectively by using hot and cold molten salt storage tanks. The molten salt storage tanks contain mixtures of NaNO3 and KNO3, at 45% and 55%, respectively. The proposed system has an overall energetic and exergetic efficiencies of 43.33% and 60.55% during the heating process, and 38.42% and 70.87% during the cooling process, respectively. To effectively operate, the system must consume 2256 kW of solar energy. The high and low‐pressure turbines have a combined power output of 713.8 kW, at an isentropic efficiency of 90%. The heating and cooling loads output from the condenser and the evaporator were calculated to be 471.7 and 316 kW, respectively. The load produced from this system can adequately satisfy the peak load conditions. The cascade system added to the evaporator will enable it to act more effectively compared to the condenser in terms of the coefficient of performance (COP). Also, the desalination system is capable of meeting the daily water requirements of 654.12 m3/day, by consuming untreated water at a flow rate of 84.71 kg/s and releasing distilled water at 7.55 kg/s.
A multivariant secure framework for smart mobile health application
Authors: Butt Shariq Aziz , Jamal Tauseef , Azad Muhammad Ajmal , Ali Arshad , Safa Nader Sohrabi 
Published: August 2019

AbstractWireless sensor network enables remote connectivity of technological devices such as smart mobile with the internet. Due to its low cost as well as easy availability of data sharing and accessing devices, the Internet of Things (IoT) has grown exponentially during the past few years. The availability of these devices plays a remarkable role in the new era of mHealth. In mHealth, the sensors generate enormous amounts of data and the context‐aware computing has proven to collect and manage the data. The context aware computing is a new domain to be aware of context of involved devices. The context‐aware computing is playing a very significant part in the development of smart mobile health applications to monitor the health of patients more efficiently. Security is one of the key challenges in IoT‐based mHealth application development. The wireless nature of IoT devices motivates attackers to attack on application; these vulnerable attacks can be denial of service attack, sinkhole attack, and select forwarding attack. These attacks lead intruders to disrupt the application's functionality, data packet drops to malicious end and changes the route of data and forwards the data packet to other location. There is a need to timely detect and prevent these threats in mobile health applications. Existing work includes many security frameworks to secure the mobile health applications but all have some drawbacks. This paper presents existing frameworks, the impact of threats on applications, on information, and different security levels. From this line of research, we propose a security framework with two algorithms, ie, (i) patient priority autonomous call and (ii) location distance based switch, for mobile health applications and make a comparative analysis of the proposed framework with the existing ones.
The evolution of intergroup tolerance in nonhuman primates and humans
Authors: Pisor Anne C. , Surbeck Martin 
Published: August 2019

AbstractPrimate individuals use a variety of strategies in intergroup encounters, from aggression to tolerance; however, recent focus on the evolution of either warfareorpeace has come at the cost of characterizing this variability. We identify evolutionary advantages that may incentivize tolerance toward extra‐group individuals in humans and nonhuman primates, including enhanced benefits in the domains of transfer, mating, and food acquisition. We highlight the role these factors play in the flexibility of gorilla, chimpanzee, bonobo, and human behavior. Given humans have an especially broad range of intergroup behavior, we explore how the human foraging ecology, especially large spatial and temporal fluctuations in resource availability, may have selected for a greater reliance on tolerant between‐community relationships—relationships reinforced by status acquisition and cultural institutions. We conclude by urging careful, theoretically motivated study of behavioral flexibility in intergroup encounters in humans and the nonhuman great apes.
Comparing flow resistance law for fixed and mobile bed rills
Authors: Di Stefano Costanza , Nicosia Alessio , Palmeri Vincenzo , Pampalone Vincenzo , Ferro Vito 
Published: August 2019

AbstractRills caused by run‐off concentration on erodible hillslopes have very irregular profiles and cross‐section shapes. Rill erosion directly depends on the hydraulics of flow in the rills, which may differ greatly from hydraulics of flow in larger and regular channels. In this paper, a recently theoretically deduced rill flow resistance equation, based on a power–velocity profile, was tested experimentally on plots of varying slopes (ranging from 9% to 26%) in which mobile and fixed bed rills were incised. Initially, measurements of flow velocity, water depth, cross‐section area, wetted perimeter, and bed slope, carried out in 320 reaches of mobile bed rills and in 165 reaches of fixed rills, were used for calibrating the theoretical flow resistance equation. Then the relationship between the velocity profile parameter Γ, the channel slope, and the flow Froude number was separately calibrated for the mobile bed rills and for the fixed ones. The measurements carried out in both conditions (fixed and mobile bed rills) confirmed that the Darcy–Weisbach friction factor can be accurately estimated using the proposed theoretical approach. For mobile bed rills, the data were supportive of the slope independence hypothesis of velocity, due to the feedback mechanism, stated by Govers. The feedback mechanism was able to produce quasicritical flow conditions. For fixed bed rills, obtained by fixing the rill channel, by a glue, at the end of the experimental run with a mobile bed rill, the slope independence of the flow velocity measurements was also detected. Therefore, an experimental run carried out by a rill bed fixed after modelling flow action is useful to detect the feedback mechanism. Finally, the analysis showed that, for the investigated conditions, the effect of sediment transport on the flow resistance law can be considered negligible respect to the grain roughness effect.
Exosomal long noncoding RNAs in aging and age‐related diseases
Authors: Cao Qidong , Guo Ziyuan , Yan Youyou , Wu Jiuping , Song Chunli 
Published: August 2019

AbstractMolecules secreted by cells into the internal environment during aging, including those secreted in exosomes, have long been a matter of concern. Those cells that absorb exosomes, also known as recipient cells, exhibit certain phenotypic changes because of the regulatory role of functional molecules (including proteins and nucleic acids) released in exosomes. Involvement of noncoding RNAs (ncRNAs) in the regulation of aging has received increasing attention, and long ncRNAs (lncRNAs) have become one of the research hotspots in recent years. LncRNAs carried by exosomes play a role in intercellular communication between adjacent and distant cells. Moreover, exosomal lncRNAs promote the decline of organ functions and the development of age‐related diseases, including atherosclerosis, Type 2 diabetes, osteoporosis, osteoarthritis, rheumatoid arthritis, Parkinson's disease, multiple sclerosis, and cancer. Here, we review the regulatory roles of exosomal lncRNAs in aging and age‐related diseases.
Estimating and accounting for the output gap with large Bayesian vector autoregressions
Authors: Morley James , Wong Benjamin 
Published: August 2019

SummaryWe consider how to estimate the trend and cycle of a time series, such as real gross domestic product, given a large information set. Our approach makes use of the Beveridge–Nelson decomposition based on a vector autoregression, but with two practical considerations. First, we show how to determine which conditioning variables span the relevant information by directly accounting for the Beveridge–Nelson trend and cycle in terms of contributions from different forecast errors. Second, we employ Bayesian shrinkage to avoid overfitting in finite samples when estimating models that are large enough to include many possible sources of information. An empirical application with up to 138 variables covering various aspects of the US economy reveals that the unemployment rate, inflation, and, to a lesser extent, housing starts, aggregate consumption, stock prices, real money balances, and the federal funds rate contain relevant information beyond that in output growth for estimating the output gap, with estimates largely robust to substituting some of these variables or incorporating additional variables.
Generalized spectral light scatter models of diverse bacterial colony morphologies
Authors: Doh Iyll‐Joon , Sturgis Jennifer , Sarria Zuniga Diana V. , Pruitt Robert E. , Robinson J. Paul , Bae Euiwon 
Published: August 2019

AbstractAn optical forward‐scatter model was generalized to encompass the diverse nature of bacterial colony morphologies and the spectral information. According to the model, the colony shape and the wavelength of incident light significantly affect the characteristics of a forward elastic‐light‐scattering pattern. To study the relationship between the colony morphology and the scattering pattern, three‐dimensional colony models were generated in various morphologies. The propagation of light passing through the colony model was then simulated. In validation of the theoretical modeling, the scattering patterns of three bacterial genera, Staphylococcus, Exiguobacterium and Bacillus, which grow into colonies having convex, crateriform and flat elevations, respectively, were qualitatively compared to the simulated scattering patterns. The strong correlations observed between simulated and experimental patterns validated the scatter model. In addition, spectral effect on the scattering pattern was studied using the scatter model, and experimentally investigated using Staphylococcus, whose colony has circular form and convex elevation. Both simulation and experiment showed that changes in wavelength affected the overall pattern size and the number of rings.
Age differences in public stigma, self‐stigma, and attitudes toward seeking help: A moderated mediation model
Authors: Mackenzie Corey S. , Heath Patrick J. , Vogel David L. , Chekay Richelle 
Published: August 2019

AbstractObjectiveStigma is commonly identified as a key reason that older adults are especially unlikely to seek mental health services, although few studies have tested this assumption. Our objectives were to: (a) examine age differences in public and self‐stigma of seeking help, and attitudes toward seeking help, and (b) see whether age moderates an internalized stigma of seeking help model.MethodsA total of 5,712 Canadians ranging in age from 18 to 101 completed self‐report measures of public stigma of seeking help, self‐stigma of seeking help, and help‐seeking attitudes.ResultsOlder participants had the lowest levels of stigma and the most positive help‐seeking attitudes. Age also moderated the mediation model, such that the indirect effect of public stigma on help‐seeking attitudes through self‐stigma was strongest for older participants.ConclusionOur findings have implications for the influence of stigma and attitudes as barriers to treatment across the adult lifespan, and for stigma reduction interventions.
MicroRNA‐326 decreases tau phosphorylation and neuron apoptosis through inhibition of the JNK signaling pathway by targeting VAV1 in Alzheimer's disease
Authors: He Bin , Chen Wei , Zeng Jingsong , Tong Wusong , Zheng Ping 
Published: August 2019

AbstractAlzheimer's disease (AD) is a progressive and age‐related neurological dysfunction. Abundant data have profiled microRNA (miR) patterns in healthy, aging brain, and in the moderate and late‐stages of AD. Herein, this study aimed to explore whether miR‐326 could influence neuron apoptosis in AD mice and how miR‐326 functions in this process. The candidate differentially expressed gene VAV1 was obtained by microarray analysis, and miRNAs that could regulate VAV1 candidate gene were predicted. Luciferase activity determination confirmed VAV1 as a target gene of miR‐326. AD mice models were established for investigating the effect of miR‐326 on AD mice. The overexpression of miR‐326 contributed to decreased time of the mice to find the platform and the escape latency and increased residence time on the target area. Besides, elevation of miR‐326 decreased Aβ deposition and contents of Aβ1–40 and Aβ1–42. Moreover, miR‐326 overexpression increased neuron cell ability, mediated cell entry, and inhibited neuron apoptosis via JNK signaling pathway. Of crucial importance, miR‐326 negatively regulated the expression of VAV1, inhibited tau phosphorylation, and blocked the activation of the JNK signaling pathway. Taken together these observations, we demonstrate that miR‐326 improves cognitive function of AD mice and inhibits neuron apoptosis in AD mice through inactivation of the JNK signaling pathway by targeting VAV1. Based on those findings, miR‐326 might exert promise as target for the treatment of AD.