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Chinese Birds 2016年第2期7卷 95-109页

作者： samuel C.Andrew Simon C.griffith Department of Biological Sciences Macquarie University

Background:Modern ecosystems contain many invasive species as a result of the activity of acclimatisation societies that operated in the second half of the nineteenth century,and these species provide good opportunities for studying invasion ***,to gain insight into the ecological and genetic mechanisms that determine the rate of colonization and adaptation to new environments,we need a good understanding of the history of the introduced species,and a knowledge of the source population,timing,and number of individuals introduced is particularly ***,any inaccuracies in the history of an introduction will affect subsequent assumptions and ***:Focusing on a single well-known species,the House Sparrow(Passer domesticus),we have documented the introduction into Australia using primary sources(*** records and newspaper articles).Results:Our revised history differs in a number of significant ways from previous *** evidence indicates that the House Sparrow was not solely introduced from source populations in England but also from germany and most strikingly also from India—with the latter birds belonging to a different *** also clarify the distinction between the number released and the number of founders,due to pre-release captive breeding programs,as well as identifying inaccuracies in a couple of well-cited sources with respect to the range expansion of the introduced ***:Our work suggests that caution is required for those studying introductions using the key sources of historical information and ideally should review original sources of information to verify the accuracy of published accounts.

关键词： Acclimatisation Bottlenecks Propagule size Range expansion Hybridisation

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Flying Capacitor Design Considerations for a 48-to-12 V,35 A Split-phase Dickson SC Converter

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Chinese Journal of Electrical Engineering 2020年第4期6卷 28-41页

作者： Richard(Yue) Sun samuel Webb Yan-Fei Liu Department of Electrical and Computer Engineering Queen's UniversityKingston K7L 3N6Canada

Switched-capacitor converters can deliver better performance,power density,and switch utilization compared to inductor-based power converters,but they suffer from current spikes during switching due to capacitor charge *** can be solved by methods such as split-phase control,which was developed to address charge redistribution in Dickson SC converters by controlling the charging and discharging of the circuit‟s flying capacitors,such that the equivalent branch voltages line up when the circuit switches ***,split-phase control is most effective at compensating for charge redistribution when all the circuit‟s flying capacitors are matched in capacitance *** between the capacitance values of the circuit flying capacitors may result in split-phase control not being able to fully compensate for charge redistribution,due to the different charge/discharge rates of the flying *** work presented in this paper provides an in-depth analysis of the sensitivity of the split-phase Dickson converter to mismatches in flying capacitor values,as well as discussions regarding the design considerations and prototype test results of a split-phase Dickson converter for high-current loads.

关键词： Switched-capacitor converter Dickson converter split-phase control capacitor mismatch

Climate Change Effects on Employment in the Nigeria's Agricultural Sector

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Chinese Journal of Urban and Environmental Studies 2023年第3期11卷 149-171页

作者： kehinde samuel ALEHILE Department of Economics Faculty of Social Sciences Kogi State University

Climate change poses mounting risks to agricultural development and rural livelihoods in *** study investigates the impacts of climate change on agricultural sector employment in Nigeria. Agriculture provides income and sustenance for much of Nigeria’s rural ***, smallholder rain-fed farming predominates, with minimal resilience to climate *** data reveal rising temperatures and declining, erratic rainfall across Nigeria’s agroecological zones since the 1970s. Crop modeling predicts further climate changes will reduce yields of key staple crops. This threatens the viability of smallholder agriculture and risks widespread job losses. The study adopts a nonlinear autoregressive distributed lag(NARDL)modeling approach to evaluate climate change effects on agricultural sector employment in Nigeria from 1990 to 2020. Findings reveal reduced rainfall initially raises employment, as farming requires more labor in dry conditions. However, protracted droughts significantly reduce agricultural jobs. Increased temperatures consistently lower farm employment through reduced yields and incomes. Based on these findings, the study recommends that adaptive strategies are urgently needed to build resilience, promote climate-smart agriculture, and safeguard rural livelihoods.

关键词： Climate change agricultural employment rainfall temperature Nigeria

Phages and their potential to modulate the microbiome and immunity

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Cellular & Molecular Immunology 2021年第4期18卷 889-904页

作者： Sara Federici samuel P.Nobs Eran Elinav Immunology Department Weizmann Institute of ScienceRehovot 7610001Israel Cancer-Microbiome Division Deutsches krebsforschungszentrum(DkFZ) Neuenheimer Feld 28069120 HeidelbergGermany

Bacteriophages(hence termed phages)are viruses that target bacteria and have long been considered as potential future treatments against antibiotic-resistant bacterial ***,the molecular nature of phage interactions with bacteria and the human host has remained elusive for decades,limiting their therapeutic *** many phages and their functional repertoires remain unknown,the advent of next-generation sequencing has increasingly enabled researchers to decode new lytic and lysogenic mechanisms by which they attack and destroy ***,the last decade has witnessed a renewed interest in the utilization of phages as therapeutic vectors and as a means of targeting pathogenic or commensal bacteria or inducing ***,the narrow host range,immense antibacterial repertoire,and ease of manipulating phages may potentially allow for their use as targeted modulators of pathogenic,commensal and pathobiont members of the microbiome,thereby impacting mammalian physiology and immunity along mucosal surfaces in health and in microbiomeassociated *** this review,we aim to highlight recent advances in phage biology and how a mechanistic understanding of phage-bacteria-host interactions may facilitate the development of novel phage-based *** provide an overview of the challenges of the therapeutic use of phages and how these could be addressed for future use of phages as specific modulators of the human microbiome in a variety of infectious and noncommunicable human diseases.

关键词： Microbiota Microbiome Phages

Risk of predation: a critical force driving habitat quality perception and foraging behavior of granivorous birds in a Nigerian forest reserve

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Avian Research 2019年第3期10卷 285-293页

作者： Umarfarooq A.Abdulwahab samuel Temidayo Osinubi Jacinta Abalaka A.P.Leventis Ornithological Research Institute University of JosJosPlateau StateNigeria Department of Watershed Sciences and the Ecology Center Utah State UniversityLoganUT 84322-5210USA FitzPatrick Institute of African Ornithology University of Cape TownRondeboschCape TownSouth Africa

Background:Understanding the factors that influence the foraging behavior and perception of habitat quality by animals has long been the focus in ecology. Due to the direct effect resource acquisition has on an individual's fitness and species' survival, predation risk is considered widely to be a major driver of foraging decision. The objectives of this study were to investigate how predation risk is perceived by granivorous bird species with respect to different habitat and microhabitat types, time of day and food types in Amurum Forest Reserve, Nigeria, with a view to direct future conservation planning. Methods: For 3 months, we conducted field experiments to measure giving-up densities (gUD, the amount of food left behind in artificial patches after birds cease to forage in it) and how it differs with habitat types, microhabitats, times of day, and food types. general linear mixed-effect models (gLMMs) were fitted to investigate the differences in gUD with respect to the aforementioned variables. Model selection was done based on the Akaike's Information Criterion (AIC). Results: There was no significant difference in gUDs across habitats. However, there was a significant difference in gUDs between microhabitats. Higher food remnants were recorded in the open than in cover microhabitats, as birds exploited food patches in the cover more. Time of day influenced foraging behavior in the birds. They foraged more in the morning than afternoon across all three habitats except for the gallery forest where birds foraged less in the morning. Higher gUDs were recorded in open than cover microhabitats both in the morning and the afternoon. Birds had a preference for rice, millet, and groundnut respectively. Conclusion:The differences in gUDs were very indicative of differences in foraging behavior and perception of resource availability in response to perceived predation risk. Therefore, this study suggests that the understanding of foraging decisions can be a veritable

关键词： Food availability Foraging behavior giving-up density Habitat quality Predation risk

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green hydrogen production from photovoltaic power station as a road map to climate change mitigation

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Clean Energy 2024年第2期8卷 156-167页

作者： kehinde Ridwan kamil Bassey Okon samuel Umar khan Department of Computer Science and Engineering Edge Hill UniversityUK Enel green Power Rome Italy Materials Research Laboratory Steelagon Engineering LimitedKaduna StateNigeria

The increasing recognition of hydrogen as a critical element in the global net-zero transition and its clear role in decarbonizing challenging sectors coincide with the growing urgency to address climate ***'s favourable renewable-energy capacity,ranging from 28%to 36%for solar,has been reported by the global solar irradiance ***,the majority of hydrogen production today relies on fossil fuels(96%),with only a small fraction(4%)being produced through water *** though there have been many studies on climate change mitigation with a focus on Africa,a green hydrogen production from a photovoltaic power station approach has not been ***,literature with a focus on Nigeria is *** study focuses on the African green hydrogen production industry,utilizing Nigeria as a case study to explore the feasibility of generating clean hydrogen vectors from a percentage of photovoltaic power output in various regions of the country through stand-alone solar grid electrification *** of the usage and effectiveness of the produced hydrogen fuel in each region are carried out,with the highest region having an annual output of 12247278 kg of green hydrogen and 8573094 kg of ammonia and the lowest region having an output of 511245 kg of green hydrogen and 357871 kg of ammonia,and the expected production from the proposed usage of 50%of the power generation output of the installed 1.6-MWp and 80-kWp solar power minigrids in the regions is *** analyses were repeated for the other considered regions in the *** results showcased the enormous advantages of the electrolytic production of hydrogen and how the greener economy project can play a major role in mitigating climate change effects and overreliance on fossil fuels as the driver of the economy in many African countries.

关键词： renewable energy photovoltaic climate change green hydrogen vector fossil fossil fuels decarbonization electrolysis

Multi-task Joint Sparse Representation Classification Based on Fisher Discrimination Dictionary Learning

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Computers, Materials & Continua 2018年第10期57卷 25-48页

作者： Rui Wang Miaomiao Shen Yanping Li samuel gomes School of Communication and Information Engineering Shanghai UniversityNo.99 Shangda RoadShanghai200444China School of Mechatronics MethodsModels and Skills Laboratory(M3M)Universite de Technologie de Belfort-Montbeliard90010 Belfort cedexBelfortFrance

Recently,sparse representation classification(SRC)and fisher discrimination dictionary learning(FDDL)methods have emerged as important methods for vehicle *** this paper,inspired by recent breakthroughs of discrimination dictionary learning approach and multi-task joint covariate selection,we focus on the problem of vehicle classification in real-world applications by formulating it as a multi-task joint sparse representation model based on fisher discrimination dictionary learning to merge the strength of multiple features among multiple *** improve the classification accuracy in complex scenes,we develop a new method,called multi-task joint sparse representation classification based on fisher discrimination dictionary learning,for vehicle *** our proposed method,the acoustic and seismic sensor data sets are captured to measure the same physical event simultaneously by multiple heterogeneous sensors and the multi-dimensional frequency spectrum features of sensors data are extracted using Mel frequency cepstral coefficients(MFCC).Moreover,we extend our model to handle sparse environmental *** experimentally demonstrate the benefits of joint information fusion based on fisher discrimination dictionary learning from different sensors in vehicle classification tasks.

关键词： Multi-sensor fusion fisher discrimination dictionary learning(FDDL) vehicle classification sensor networks sparse representation classification(SRC)

Anti-inflammatory and analgesic activities of Melanthera scandens

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Asian Pacific Journal of Tropical Biomedicine 2012年第2期2卷 144-148页

作者： Jude E Okokon Anwanga E Udoh samuel g Frank Louis U Amazu Department of Pharmacology and Toxicology Faculty of PharmacyUniversity of Uyo Department of Science Technology Akwa Ibom State PolytechnicIkot Osurua Department of Pharmacology and Therapeutice.College of Medicine Evans Enwerem University

Objective:To evaluate the anti-inflammatory and analgesic activities of leaf extract of Melanthera scandens(***).Methods:The crude leaf extract(39-111 mg/kg)of *** was investigated for anti-inflammatory and analgesic activities using various experimental *** anti-inflammatory activity was investigated using carragenin,egg-albumin induced oedema models,while acetic acid,formalin-induced paw licking and thermal-induced pain models were used to evaluate the antinociceptive ***:The extract caused a significant(Pgents ***:The leaf extract possesses anti-inflammatory and analgesic effects which may be mediated through the phytochemical constituents of the plant.

关键词： Melanthera scandens Anti-inflammatory Analgesic

Combining material characterization with single and multi-oxyanion adsorption for mechanistic study of chromate removal by cationic hydrogel

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Journal of Environmental Sciences 2011年第6期23卷 1004-1010页

作者： Irene M.C.Lo samuel C.N.Tang Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina

Cationic hydrogel with magnetic property was synthesized via radical polymerization and its removal capacity of chromate from contaminated water was found to be 200 mg/*** Fourier transform infrared spectroscopy（FT-IR） study,the mechanism of chromate removal by hydrogel was found to be non-specific adsorption,mainly due to ion exchange,as evidenced by the positively charged functional group,trimethyl ammonium-N＋（CH3）3,in the *** were accordingly determined by testing di？erent oxyanion adsorption onto the *** results of the chromate adsorption experiments illustrated that the amount of chromate adsorbed was nearly equal to that of the chloride released from the hydrogel,which is part of the evidence for ion *** and multi-oxyanion adsorption experiments were also performed,and it was demonstrated that ion removal was species independent,but charge dependent,another characteristic of the ion exchange *** was found that the same Langmuir model can be applied to best fit the findings of single and multi-oxyanion adsorption,which further indicates the mechanism of chromate removal is attributed to ion *** view of the above,the background anions compete for adsorption sites with chromate,evidenced by inhibitive chromate removal in the presence of background electrolytes in the batch studies,further echoing the ion exchange mechanism.

关键词： adsorption magnetic hydrogel mechanism ion exchange oxyanion

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Moments of the folded logistic distribution

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Progress in Natural Science:Materials International 2007年第6期17卷 696-697页

作者： Saralees Nadarajah samuel kotz School of Mathematics University of ManchesterManchester M60 1QDUK Department of Engineering Management and Systems Engineering George Washington UniversityWashingtonDC 20052USA

The recent paper by Cooray et al. introduced the folded logistic distribution. The moments properties given in the paper appear too complicated. In this note, a simple formula is derived in terms of the well known Ler... 详细信息

关键词： folded logistic distribution Lerch function moments.