1,245 research outputs found
Neotropical Seasonally Dry Forests: Response of Soil Fungal Communities to Anthropogenic Actions
The aim of this review was to analyze the information available on soil fungal community of Neotropical Seasonally dry forests, with special attention given to the Chaco area. This review is focused on the loss of soil fungal community due to anthropogenic actions such as forest clearing. Over the last decades, the expansion of the agricultural frontier has had a wide range of physical, chemical and biological effects on Neotropical dry forests. As these changes on the Schinopsis dry forests (Chaco) have rendered the ecosystem vulnerable, these areas have become some of the few protected areas in South America. After analyzing both national and international studies to find the latest research available on the topic we have noticed there is lack of specific studies on soil fungal community in the Chaco area, unlike Cerrado and Caatinga where most studies have been carried out. Therefore, we propose to conduct more in-depth studies on soil fungi in Schinopsis forests to revalue the Chaco fungal community to use them as potential indicators of soil health and to develop new management techniques.Fil: Merlos, Cristina Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnolológico Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología. Laboratorio de Biología Funcional y Biotecnología; ArgentinaFil: Pelizza, Sebastian Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Moreno, Maria Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnolológico Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología. Laboratorio de Biología Funcional y Biotecnología; Argentin
El ratolí com a sistema model en biologia
Des de l'establiment de les primeres soques de laboratori al començament del segle xx,
el ratolí s'ha convertit en una eina fonamental en la recerca en biologia. Múltiples models
experimentals han permès ampliar el nostre coneixement en camps com l'embriogènesi,
la fisiologia o la biomedicina, entre d'altres. El desenvolupament de les tecnologies de
modificació genètica ha consolidat definitivament el ratolí com el mamífer d'elecció a
l'hora de caracteritzar patrons d'expressió, funcions i interaccions entre gens, així com en
la modelització de malalties humanes i l'assaig de nous fàrmacs. Aquest capítol pretén
oferir una visió general de les àmplies possibilitats que es deriven de l'ús del ratolí en el
laboratori i inclou exemples que demostren per què és un element clau en la recerca en
biologia actualment.The mouse as a model system in biology. Since the beginning of the 20th century, when the first laboratory strains were developed,
the mouse has become a central tool in biological research. Many experimental
models have allowed the broadening of our knowledge in scientific fields such as embryogenesis,
physiology or biomedicine. Development of genetic modification techniques
has definitely established the mouse as the mammal organism of choice for the characterization
of gene expression patterns, functions and interactions among genes as well as for
the modeling of human diseases and drug testing. This chapter wants to offer a general
view on the possibilities derived from the use of the mouse in the laboratory, and includes
examples showing why it has become a key element in biological research
Pattern and process in crop species diversity and lime requirements models
Tesis para obtener el grado de Doctor of Philosophy in Horticulture and Agronomy, de la University of California Davis, 2022Changes in crop species diversity can affect agroecosystem function. However, most crop diversity studies insufficiently account for the influence of scale on spatial crop diversity, and its relation to temporal diversity has not been explored. Moreover, crop diversity might be limited by environmental constraints and market demand for specific crops, which needs to be considered when assessing opportunities for diversification. This dissertation developed and applied new approaches to gaining a quantitative understanding of diversity patterns and processes, allowing for improved comparison between regions and countries. It includes an analysis of the scale dependency of crop species diversity and its relation with temporal diversity using high-resolution crop-specific land-cover data for the conterminous US. It also shows the magnitude of environmental and demand-side constraints to crop diversity globally. For that purpose, a theoretical framework of hierarchical levels of crop species diversity is presented, in which potential, attainable, and current diversity levels are compared to compute diversity gaps. We found that spatial diversity monotonically increases with the size of the observational unit, and the strongest association between spatial and temporal diversity is observed when measured in areas comparable to farm sizes. In larger areas, the association weakens because of the increasing diversity among farms. At the national level, the diversity among farms is usually higher than the diversity within them, which needs to be considered when inferring diversity effects with national-level data. v Environmental limits to crop diversity are higher in temperate and continental areas than in tropical and coastal regions. Crop diversity is also constrained by a high demand for a few crop species, which results in an attainable diversity that is much lower than the potential. Nevertheless, there are large gaps between current and attainable diversity levels in most croplands. These gaps are particularly large in the Americas, where croplands are dominated by a few major annual crops (maize, soybean, wheat) mostly grown on fields with a very low temporal diversity. In contrast, diversity gaps are relatively small in Europe and East Asia. Changes in food demand favoring minor crops could positively impact spatial and temporal crop species diversity by increasing the attainable diversity. But given current consumption patterns, the most effective strategy to increase crop diversity in areas with high diversity gaps might be to expand the area of a major crop adapted to that specific environment, but that is not widely planted. Securing adequate soil fertility is also critical for diversification, especially in the tropics, where low soil pH is one of the main limiting factors of potential crop diversity, and soil acidity remains a key management challenge for smallholder farmers. Liming can boost the productivity of acid soils, but the lime rate required to achieve this is unknown for many tropical regions where food production increases are urgently needed. Therefore, lime requirement models based on readily available soil data could be very useful in these places. However, the great variety of lime requirement models available in the literature introduces much uncertainty. We evaluated current lime requirement models for acid tropical soils and introduced a new model based on acidity saturation using data from four soil incubation studies and 31 soil types. Foundational models based on acidity or base saturation are reasonably accurate (r ≥ 0.9), but later attempts to vi improve these models were unsuccessful. The new model, in contrast, has more precision than all earlier models across a wide range of acid tropical soils from different regions. Moreover, lime requirement estimates largely depend on the target soil chemical property of the model. For instance, many more African soils would require liming based on base saturation models than acidity saturation models, regardless of the accuracy. The new acidity saturation model can effectively estimate the lime rate required to address aluminum toxicity. This model could be incorporated into more comprehensive models once lime rates needed for other acidity problems are well established.EEA BalcarceFil: Aramburu Merlos, Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina
Internet como instrumento para la Yihad
Las extraordinarias ventajas que ofrece Internet lo han convertido en un instrumento clave y dinámico en la estrategia de los yihadistas. Los medios de comunicación, la clase política y las agencias de seguridad e información han tendido a concentrar susThe great virtues of the Internet ease of access, lack of regulation, vast potential audiences and fast flow of information have been turned to the advantage of destructive groups and cells committed to terrorizing societies to achieve their goals. The m
Recommended from our members
Has the passage of Proposition 227 had an effect on the redesignation rates of English language learners in the Rialto Unified School District?
The purpose of the project was to develop a study that would test whether the promise of students learning to speak English fluently in a shorter amount of time was met by Proposition 227
Valoración mediante una encuesta de la negativa a la vacunación frente al virus del papiloma humano: estudio de la información al paciente
Treball Final de Grau en Medicina. Codi: MD1158. Curs acadèmic: 2016-2017OBJETIVO: La vacuna contra la infección del Virus del Papiloma Humano (VPH) es el medio más
eficaz y seguro para la prevención del cáncer de cérvix. En España, se aprobó la vacunación en
el año 2007 y un año más tarde se implantó en el Calendario de Vacunación Sistemática
Infantil de la Comunidad Valenciana. No obstante, las coberturas vacunales en la comunidad
no alcanzan los objetivos propuestos. El presente trabajo propone identificar cómo influyen las
vías de información en la decisión, de padres y adolescentes, de rechazar la vacuna.
MÉTODO: Se contactará vía telefónica con los padres o adolescentes de una muestra
representativa de las pacientes nacidas entre 1994 y 2004 adscritas al Centro de Salud Illes
Columbretes. Se les informará de manera sistemática mediante un texto consensuado entre
los investigadores. Si el entrevistado está de acuerdo, se le realizará la encuesta.
RESULTADOS: Se realizaron 120 llamadas, 56 sujetos no respondieron la encuesta, entre los
cuales 36 estaban vacunados. De los 64 restantes que realizaron el cuestionario, las vías de
suministro de información más influyentes son: el pediatra, internet y televisión. Además,
observamos que existe una gran desinformación entre los sujetos del estudio.
CONCLUSIÓN: Para mejorar las coberturas de vacunación se deben aplicar medidas con el fin
de que la información de calidad llegue a todas las adolescentes y sus familias, y así, fomentar
la decisión de vacunarse y mejorar la salud poblacional.OBJECTIVE: The Human Papillomavirus (HPV) vaccine is the most effective and safe way to
prevent cervical cancer. In Spain, vaccination was approved in 2007 and implemented a year
later in the Children Systematic Vaccination Calendar in the Valencian Community. However,
the acceptance of the vaccine in the community does not meet the proposed objectives. The
present work proposes to identify how the information channels negatively influence parents
and adolescents’ willingness to receive the vaccine against HPV.
METHODOLOGY: A representative sample of parents or adolescents born between 1994 and
2004 and who are patients of the Illes Columbretes Health Center will be contacted by
telephone. They will be systematically informed using a consensus text agreed between
researchers. If the interviewee agrees, the survey will be conducted.
RESULTS: 120 calls were made, 56 subjects did not respond to the survey, among which 36 had
been vaccinated. Of the remaining 64 who filled out the questionnaire, the most influential
sources of information were: the pediatrician, internet and television. In addition, we observe
that there is a great deal of disinformation between the subjects of the study.
CONCLUSION: In order to improve vaccine coverage, measures should be taken to ensure that
quality information reaches all adolescents and their families, thus encouraging the decision to
vaccinate and improve population health
352— Investigating the function of MHC Class I in \u3ci\u3eXenopus laevis\u3c/i\u3e tadpoles
Xenopus laevis, is an excellent model organism for transgenesis and immunological research due to their large eggs and the similarities between mammalian and amphibian immune systems. MHC Class I is found on nearly all cells and educates T cells to recognize between self and non-self which is an essential immune system function. However, tadpoles don’t have detectable MHC Class I expression while adult frogs do. Despite this tadpoles are still immunocompetent; thus the role of MHC Class I in tadpoles is unknown. To investigate MHC Class I function we inactivated the corresponding gene in Xenopus laevis using CRISPR/Cas9. The CRISPR/Cas9 gene editing system has two components; a guide RNA that targets a specific DNA sequence and the Cas9 protein that cuts the DNA. After the DNA is cut, the cell repairs the DNA break, which introduces mutations that theoretically inactivate this gene. Previously, we generated transgenic tadpoles with potentially inactivated MHC Class I genes, and we are in the process of determining the success of our transgenesis. To detect MHC Class I inactivation we will use PCR to amplify the MHC class I gene from genomic DNA of the transgenic tadpoles which will then be sent for sequencing
Potential, attainable, and current levels of global crop diversity
High levels of crop species diversity are considered beneficial. However, increasing diversity might be difficult because of environmental constraints and the reliance on a few major crops for most food supply. Here we introduce a theoretical framework of hierarchical levels of crop diversity, in which the environmental requirements of crops limit potential diversity, and the demand for agricultural products further constrain attainable crop diversity. We estimated global potential, attainable, and current crop diversity for grid cells of 86 km2 . To do so, we first estimated cropland suitability values for each of 171 crops, with spatial distribution models to get estimations of relative suitability and with a crop model to estimate absolute suitability. We then used a crop allocation algorithm to distribute the required crop area to suitable cropland. We show that the attainable crop diversity is lower in temperate and continental areas than in tropical and coastal regions. The diversity gap (the difference between attainable and current crop diversity) is particularly large in most of the Americas and relatively small in parts of Europe and East Asia. By filling these diversity gaps, crop diversity could double on 84% of the world’s agricultural land without changing the aggregate amount of global food produced. It follows that while there are important regional differences in attainable diversity, specialization of farms and regions is the main reason for low levels of local crop diversity across the globe, rather than our high reliance on a few crops.EEA BalcarceFil: Aramburu Merlos, Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Aramburu Merlos, Fernando. University of California Davis. Department of Environmental Science and Policy; Estados Unidos.Fil: Hijmans, Robert J. University of California Davis. Department of Environmental Science and Policy; Estados Unidos
Concreció de les competències bàsiques al cicle inicial d'educació primària. Una proposta
En aquest article s'aporta una proposta, una eina, un instrument per avaluar les vuit competències bàsiques al cicle inicial de l'educació primària. Us expliquem el treball fet pel col·lectiu de docents que formen el grup GROC de l'Ebre. La idea que guia el treball és l'elaboració d'uns documents que posem a disposició de la comunitat educativa que puguin servir-los per organitzar l'atenció a la diversitat de tot l'alumnat des d'un plantejament curricular per competències. Al llarg de l'article us expliquem el procés seguit en aquesta elaboració. En la part final presentem els indicadors d'assoliment pensats per a cada competència i el model de registre previst per fer la sistematització dels resultats obtinguts.Specifying key skills in the initial cycle of primary education (6-8 yrs). A proposal. This article puts forward a proposal, a tool, and an instrument to assess the eight key skills in the initial cycle of primary education (6-8 yrs). We explain the work done by the group of teachers who collaborate on the GROC de lEbre working group. The idea that guides the work is the elaboration of a number of documents to make them available to the educational community, thus helping it to organise the attention that should be paid to the diversity of all pupils from a competence-based curricular approach. Throughout the article, we explain the process applied to elaborate these documents. In the final section, we present some indicators of attainment designed for each competence, as well as the assessment/registration model to systematise the results obtained
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