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Crystal structure and magnetic properties of YbZn_(0.7)In_(1.3)

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journal of Rare Earths 2011年第10期29卷 943-945页

作者： Yu.Verbovytskyy L.C.j.pereira A.P.Gon alves Department of Chemistry Nuclear and Technological InstituteNational Rd.102686-953SacavémPortugal

The new ternary YbZn0.7Inl.3 compound was synthesized in evacuated quartz ampoules at 900 ℃, followed by annealing at 400 ℃. It crystallized in the UHg2 structure type with a=0.47934（5） nm, c=0.36955（5） nm, V=0.073535（15） nm3. The shortest distances between the atoms in this structure were equal to 0.3696 nm （Yb-Yb）, 0.3328 nm （Yb-M） and 0.2767 nm （M M）, respectively. Magnetization measurements indicated that the title compound exhibited a paramagnetic behavior down to 2 K, with antiferromagnetic-like interactions. Calculated magnetic moment for YbZn0.7inl.3 （μeft =3.86μB/Yb） could indicate mixed valence state of Yb.

关键词： ytterbium intermetallics crystal structure magnetic measurements rare earths

Inductively coupled plasma emission spectroscopic and flame photometric analysis of goat epididymal fluid

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Asian journal of Andrology 2000年第4期2卷 288-292页

作者： Meenakshi Gaur Vikas Pruthi Ramasare Prasad Ben M.j.pereira Reproductive Biology Laboratory Dept. of Bioscience and Biotechnology University of Roorkee Roorkee-247 667 U. P. IndiaReproductive Biology Laboratory Dept. of Bioscience and Biotechnology University of Roorkee Roorkee-247 667 U. P. IndiaReproductive Biology Laboratory Dept. of Bioscience and Biotechnology University of Roorkee Roorkee-247 667 U. P. IndiaReproductive Biology Laboratory Dept. of Bioscience and Biotechnology University of Roorkee Roorkee-247 667 U. P. India

Aim: The elemental composition of the epididymal luminal fluid (ELF) in adult goat ( Capra indica) was investigat-ed. Methods: ELF was collected by micropuncture from twelve sites along the epididymal duct. The elementalcontents was analyzed with inductively coupled plasma (ICP) emission spectroscopy, a microanalytical technique thatcan simultaneously measure many elements in minute volumes of sample. The Na and K concentrations were determinedby flame photometry. Results: ICP spectroscopy showed the presence of copper, calcium, nickel, iron, magne-sium, chromium, titanium and zinc in ELF, with fluctuating levels at different sites along the length of the ***, cobalt, lead and manganese were not fotmd. The Na^+ / K^+ ratio was seen to be higher at the initial seg-ments of the epididymis and lower at the distal. Conclusion: It is proposed that the observed characteristic distribu-tion of elements in ELF may have far reaching implications in sperm maturation and storage known to occur in the epi-didymis. (Asian j Androl 2000 Dec; 2: 288-292)

关键词： goat epididymis epididymal luminal fluid elements spectroscopy flame photometry

The effect of abiotic stresses on plant C:N:P homeostasis and their mitigation by silicon

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The Crop journal 2024年第2期12卷 340-353页

作者： Milton Garcia Costa Renato de Mello Prado Luiz Fabiano Palaretti jonas pereira de Souza júnior Department of Agricultural Production Science School of Agricultural and Veterinarian SciencesSão Paulo State UniversityJaboticabalBrazil

In crop plants, various environmental stresses affect the balance of carbon, nitrogen, and phosphorus(C:N:P), leading to biochemical and physiological alterations and reductions in yield. Silicon(Si) is a beneficial element that alleviates plant stress. Most studies involving silicon have focused on physiological responses, such as improvements in photosynthetic processes, water use efficiency, and antioxidant defense systems. But recent research suggests that stressed plants facing either limited or excessive resources(water, light, nutrients, and toxic elements), strategically employ Si to maintain C:N:P homeostasis, thereby minimizing biomass losses. Understanding the role of Si in mitigating the impact of abiotic stresses on plants by regulating C:N:P homeostasis holds great potential for advancing sustainable agricultural practices in crop production. This review presents recent advances in characterizing the influence of environmental stresses on C:N:P homeostasis, as well as the role of Si in preserving C:N:P equilibrium and attenuating biological damage associated with abiotic stress. It underscores the beneficial effects of Si in sustaining C:N:P homeostasis and increasing yield via improved nutritional efficiency and stress mitigation.

关键词： Nutritional stoichiometry Elemental stoichiometry Beneficial element Environmental stresses Nutritional efficiency Carbon use efficiency Agricultural sustainability

Dispersal behavior of yellowjacket （Vespula germanica） queens

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Insect Science 2018年第1期25卷 109-116页

作者： Maite Masciocchi Andres S. Martinez Aria j. pereira jose M. Villacide juan C. Corley CONICET CCT Comahue INTA Grupo de Ecologia de Poblaciones de Insectos INTA EEA Bariloche Argentina Centro Regional Universitario Bariloche U. N. del Comahue Bariloche 8400 Argentina

Understanding the factors that affect animal dispersal behavior is important from both *** and applied perspectives. Dispersal can have clear evolutionary and ecological consequences, but for normative insect pests, dispersal capacity can also help to explain invasion success. Vespula germanica is a social wasp that, in the last century, has successfully invaded several regions of the world, showing one of the highest spread rates reported for a nonnative insect. In contrast with nonsocial wasps, in social species, queens are responsible for population redistribution and spread, as workers are sterile. For V. germanica, it has been observed that queen flight is limited to 2 distinct periods： early autumn, when new queens leave the nest to mate and find sheltered places in which to hibernate, and spring when new colonies are founded. Our aim was to study the flight behavior of V. germanica queens by focusing on the different periods in which dispersal occurs, characterizing as well the potential contribution of queen flight （i.e., distance） to the observed geographical spread. Our results suggest that the distances flown by nonover- wintered queens is greater than that flown by overwintered individuals, suggesting that the main queen dispersal events would occur before queens enter hibernation. This could relate to a behavioral trait of the queens to avoid the inbreeding with related drones. Additionally, given the short distances flown and remarkable geographical spread observed, we provide evidence showing that queen dispersal by flight is likely to contribute proportionately less to population spread than human-aided factors.

关键词： flight potential German wasps hibernation invasive wasps social insect

Caring to Teach: Exploring the Affective Economies of English Teachers in Singapore

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Chinese journal of Applied Linguistics 2018年第4期41卷 488-505,552页

作者： Andrew j.pereira Nanyang Technological University National Institute of Education(NTU/NIE)Singapore

The ethical project of education hinges on the ideal of caring relations between teachers and students, an ideal that entails deep emotional commitments on the part of teachers. Drawing on interview data from a larger study of teachers’ lived experiences in Singapore’s secondary schools,this paper examines the cultural politics of caring as an emotional practice in teaching. The ethic of care serves to construct normative accounts of good teaching based on "feeling rules," and becomes a disciplinary technology for evaluating the professional, social and emotional competencies of teachers. I suggest that this project in turn entails an ideological effort to mobilize teachers’ emotional attachment to this ethical ideal. The ethic of care shapes the subjectivities, beliefs, and practices of English teachers, particularly as they circulate through the neoliberal imperatives of educational accountability regimes.

关键词： neoliberalism governmentality caring emotions affect cultural politics

Identity(ies)and Transnationalization of Brazilian Evangelical Churches in Portugal:Case study of World Cathedral of Hope and Victory in Christ Churches

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Cultural and Religious Studies 2024年第3期12卷 133-145页

作者： jonas pereira de Oliveira júnior University of Porto PortoPortugal

The presence of evangelicals in Brazil is a social and religious phenomenon that has aroused interest of many scholars due to its rapid and significant expansion in recent decades and its projection beyond national *** evangelical denominations that stand out in this scenario are Pentecostal churches,which have developed intense missionary activity in several countries,including *** this article,we intend to analyze features and challenges of Brazilian evangelical churches:World Cathedral of Hope(CIME)(Catedral Mundial da Esperança-ICME)and Assembly of God Victory in Christ(ADVEC)(Assembleia de Deus Vitória em Cristo-ADVEC)that operate in Portugal,seeking to understand issues of identity and belonging of these communities,their models of transnationalization,its evangelization strategies and its adaptations to Portuguese context,in the period from 2000 to 2020.

关键词： identity transnationalization secularization Brazilian migration

Convective Rainfall Systems in the La Plata Basin

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Atmospheric and Climate Sciences 2014年第4期4卷 757-778页

作者： Augusto j. pereira Filho Richard E. Carbone john D. Tuttle University of Sã o Paulo Institute of Astronomy Geophysics and Atmospheric Sciences Department of Atmospheric Sciences S&atilde o Paulo Brazil National Center for Atmospheric Research Colorado USA

Hourly rainfall estimates from integrated satellite data are used to build a dynamically based climatology of convectively generated rainfall across the La Plata Basin in South America and adjacent oceans. Herein, the focus of this manuscript is on 20S to 35S, including the Andes cordillera. Emphasis is placed on rainfall resulting from organized convective regimes which are known to produce the majority of seasonal rainfall in Southern South America and other continents. The statistical characteristics of individual events are quantified and examined with respect to regional atmospheric conditions. Among the factors considered are steering winds and wind shear, convective available potential energy (CAPE), localized sensible and latent heat sources over mountains and wetlands (Chaco), and the occurrence of baroclinic waves such as mid-latitude jet stream transient disturbances. Forcing and convective triggering mechanisms are inferred from the diagnosis of systematic patterns as evidenced in the continental diurnal cycle and longer periods of natural variability. The diurnal cycle of rainfall is especially informative with respect to the frequency and phase of rainfall associated with long-lived propagating rainfall “episodes”. Similar to findings in tropical northern Africa and tropical northern Australia, there is a strong presence of organized convection, which can propagate zonally hundreds to thousands of km as a coherent sequence of mesoscale convective systems. Convective triggering is often associated with elevated terrain, the Andes, and the La Plata basin region, which is especially rich in moist static energy. The passage of baroclinic waves over the Andes is consistent with eastward propagating clusters of convection, within which westward-propagating systems also reside. These organized convective systems over the La Plata Basin are analyzed with hourly rainfall estimates with CMOPRH method. Rainfall estimates at 8-km spatial resolution were obtained b

关键词： Satellite-Derived Rainfall Organized Convection La Plata Basin Diurnal Cycle

The African Elephant (<i>Loxodonta africana</i>): Mini-Review of an Endangered Species

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Natural Resources 2020年第8期11卷 317-350页

作者： Ana Raquel de Sales Rita Sofia Santos Anastácio M. j. pereira Department of Biology University of Aveiro Aveiro Portugal Independent Researcher Aveiro Portugal

Humankind is responsible for conditioning the distribution of species, including the African elephant. From its great physical form to its fascinating social behaviour, Loxodonta africana can trigger an admiration in some and be undervalued by others, often ending up being a victim of human activities. Increasingly, the apparent impossibility of the coexistence of these two species represents a problem for the conservation of the large African mammal. Here it was reviewed the published bibliography about the African savannah elephant (L. africana), between July 2015 and December 2019. The Web of Science (WoS) database enabled the search for the words “Loxodonta africana”. From this research, we obtained 310 articles, 149 of them were analysed. Elephants have characteristics that define its uniqueness that are constantly reported, such as: its cognition and extraordinary memory, factors that influence its movements and its distribution, its specific vocalization and the strong dependence on social connections. Threats to the conservation of the species and the urgency of interventions are also an important subject of discussion. Poaching for ivory represents a major obstacle on conservation and has been drastically reducing the number of elephant populations and causing future consequences for those who thrive. Law enforcement in reducing/prohibit po

关键词： Behaviour Ecosystem Engineer Environmental Awareness Human-Wildlife Conflict Loxodonta africana Mitigation Strategies Poaching Wildlife Conservation

Sea Turtle Nesting: What Is Known and What Are the Challenges under a Changing Climate Scenario

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Open journal of Ecology 2022年第1期12卷 1-35页

作者： Raquel A. M. São Miguel Rita Anastácio Mário j. pereira Department of Biology University of Aveiro Aveiro Portugal Independent Researcher Aveiro Portugal Department of Biology & CESAM (Centre for Environmental and Marine Studies) University of Aveiro Aveiro Portugal

The rate of climate change experienced globally in recent decades may compromise sea turtles’ survival;especially temperature increase, which is particularly fast, impacts life history characteristics, such as temperature-dependent sex determination (TSD), late maturity and sea turtles highly migratory nature. This review aims to identify and summarize the information that has been collected from 2009-2020 in order to aid future empirical studies that seek to fill these and other knowledge gaps, and subsequently assist conservationists in making multilevel decisions to protect sea turtle populations and species. In a summarized way the general knowledge acquired so far on the influence of environmental abiotic and biotic factors on nesting behaviour and hatching, emergence and survival successes of sea turtle hatchlings, was gathered. To accomplish this work, a search on Web of Science, Science Direct, NCBI/PubMed, and Google Scholar was carried out using the terms “sea turtles + climate change”. Published articles in the period 2009-2020 were selected, related to the nesting ecology of 5 species of sea turtles: Caretta caretta, Eretmochelys imbricata, Dermochelys coriacea, Chelonia mydas, Lepidochelys olivacea. Emphasis was also placed on geographical information and on population location (e.g. climatic conditions during the nesting season). These articles (N = 126) were analysed giving relevance to researcher’s data interpretations, comparisons with other researches, and the reached conclusions. An attempt was made to represent all 5 species of sea turtles when selecting articles on each of the environmental factors that influence sea turtle nesting: temperature, humidity, nesting substrate, gases, depth of the nest, sea surface temperature (SST), nest location on the beach, nesting phenology and geographic distribution of nesting habitats. The interaction between these parameters and their consequences on the terrestr

关键词： Reproductive Ecology Sea Turtles Climate Change Nesting Phenology and Geographic Distribution of Nesting Habitats