As (i)limitações da pesquisa histórica em educação

Believe in meBecause I don't believe in anythingAnd I want to be someone to believe.Counting Crows" Mr Jones" in August and everything.Em termos gerais, este trabalho se deriva da necessidade de compreender o significado irrestrito da pesquisa histórica. Assim, questões relativas ao próprio conceito, às abordagens, aos fatos do passado e às fontes e suas respectivas críticas, fizeram parte de um todo que foi visto com uma curiosidade reconceitualizante. A partir desse intuito se traçou o objetivo maior que norteou os passos deste estudo: Delinear as características teórico-metodológicas da inquirição histórica entendida como uma atividade de autêntica reconstrução do passado

Work-related injuries among child street-laborers in Latin America: Prevalence and predictors

Objectives. To determine the prevalence and nature of occupational injuries among children working in the streets of four major cities in Latin America, as well as to identify factors that predict these work-related injuries. Methods. This cross-sectional study interviewed 584 children from 5-17 years of age working on the streets of Bogota, Colombia; Lima, Peru; Quito, Ecuador; and São Paulo, Brazil. Descriptive analyses and multivariate logistic regressions were conducted, with incidence and serious injuries regressed on occupational and sociodemographic variables. Results. Approximately 39.6% of the child street-laborers surveyed reported an injury sustained while working in the streets: scratches (19.5%), cuts/lacerations (16.4%), bums (8.6%), car accidents (8.9%), sprains (4.6%), and amputations (0.3%). Working a high number of daytime hours and performing on the street predicted the greatest risk of injury, even after controlling for sociodemographic factors; specifically, each additional hour of daytime work increased the risk of injury by 1.4%. Child performers had three times the injury rate of children primarily selling products. Boys, older children, and children in Quito were more likely to experience moderate-to-severe injuries, than girls, younger children, and street children in the other study cities. Conclusions. Interventions are needed to address the substantial risk of injury experienced by children working on the city streets of Latin America

Problema de pesquisa e hipótese argumentativa: uma proposta para a pesquisa em educação

A proposta apresentada neste artigo aponta para o redimensionamento do significado da hipótese de pesquisa. Nas últimas duas décadas os cientistas sociais do nosso país limitaram-se a privilegiar a formulação do problema em detrimento do enunciado da hipótese. Este fato nos levou a construir uma contra-argumentação que propõe a reciprocidade indicotomizável entre problema e hipótese de investigação

Trigger efficiencies of a proposed beam monitoring detector (BeBe) for p+p collisions at NICA energies

The Multipurpose Detector (MPD) consists of a typical array of sub-detectors to study the nuclear matter originating from the collisions of beams provided by the Nuclotron-based Ion Collider fAcility (NICA). A beam monitoring detector~(BeBe) is proposed for stage 2 of MPD to increase the trigger capabilities. BeBe is constituted of two plastic scintillator disks segmented in 80 cells $\pm~2~m$ away from the interaction point of MPD. Laboratory measurements to obtain the energy resolution of an individual BeBe cell prototype are presented. It is shown that an energy resolution of $22\pm6\%$ can be obtained. Based on Monte Carlo simulations, the trigger efficiencies of the BeBe are presented for p+p collisions at 11~GeV considering a threshold in the energy loss of the charged particles reaching the detector

American triatomine species occurrences: updates and novelties in the DataTri database

The causative agent of Chagas disease (Trypanosoma cruzi) is transmitted to mammals, including humans, mainly by insect vectors of the subfamily Triatominae (Hemiptera: Reduviidae). Also known as “kissing bugs”, the subfamily currently includes 157 validated species (154 extant and three extinct), in 18 genera and five tribes. Here, we present a subdataset (7852 records) of American triatomine occurrences; an update to the most complete and integrated database available to date at a continental scale. New georeferenced records were obtained from a systematic review of published literature and colleague-provided data. New data correspond to 101 species and 14 genera from 22 American countries between 1935 and 2022. The most important novelties refer to (i) the inclusion of new species, (ii) synonymies and formal transferals of species, and (iii) temporal and geographical species records updates. These data will be a useful contribution to entomological surveillance implicated in Chagas disease.Centro de Estudios Parasitológicos y de Vectore

Urinary Excretion of Mimosine Derivatives by Cows with and without Experience in Consumption of \u3cem\u3eLeucaena leucocephala\u3c/em\u3e

Leucaena leucocephala is a leguminous tree widely distributed in the tropical regions of the world. In Mexico, it has been incorporated into silvopastoral systems and is highly regarded, owing to its high content of crude protein. Nonetheless, L. leucocephala contains secondary metab-olites, such as mimosine, a non-protein free amino acid, which may induce toxic effects in unadapted ruminants that consume the forage (Hammond 1995). Although Synergistes jonesii, an anaerobic bacterium, has the ability to degrade 3,4-DHP and 2,3-DHP to non-toxic compounds (Allison et al. 1992), in Mexico its presence has not yet been confirmed. Recent work has suggested the occurrence of sub-clinical toxicity to 3,4-DHP and 2,3-DHP in cattle grazing L. leucocephala in Australia and Thailand (Graham 2007; Dalzell et al. 2012; Phaikaew et al. 2012). Several options such as the transfer of rumen liquor and the adaptation of ruminants to the intake of L. leucocephala have been studied in an attempt to reduce the excretion of mimosine and its metabolites (Palmer et al. 2010). The aim of the present work was to evaluate the effect of the experience of consumption of L. leucocephala on excretion of mimosine derivatives (3,4-DHP and 2,3-DHP) in the urine of cattle

Análisis didáctico de conocimientos previos sobre divisibilidad, de estudiantes que ingresan a la universidad usando como herramienta el ‘análisis estadístico implicativo’

Este trabajo tiene por objetivo indagar sobre los saberes de divisibilidad de los estudiantes a través de sus respuestas a dos ítems de una evaluación mediante un análisis didáctico en el que se emplearon los resultados obtenidos por la herramienta Análisis Estadístico Implicativo (ASI). De este modo se quiere identificar definiciones, propiedades, procedimientos y argumentos y las relaciones conceptuales que se establecen entre estos objetos en las prácticas realizadas por los estudiantes.ASI, a partir de la hipótesis de que, si un ítem a es más complejo que otro b, permite detectar relaciones del tipo “si a, entonces, casi siempre b”, a las cuales se las denomina cuasi-implicaciones o reglas. Estas relaciones se presentan mediante un “grafo implicativo” para una mejor interpretación de los resultados obtenidos.A modo general, se observaron relaciones de intensidades menores a 0.9 lo que permite afirmar que pocos estudiantes lograron establecer relaciones conceptuales que den cuenta de un alto grado de comprensión respecto a la divisibilidad de números enteros

Productive Performance of Growing Cattle Grazing a Silvopastoral System with \u3cem\u3eLeucaena leucocephala\u3c/em\u3e

In tropical regions, the feeding of cattle is usually based on the grazing of medium to low quality grasses. Low fertility of soils, changing climatic conditions and the poor management of pastures, have further reduced the quality and forage yield of pastures. The low availability and quality of grasses gives modest weight gains for grazing cattle and this in-turn causes low economical efficiency of cattle production systems (Campos et al. 2011). Silvopastoral systems represent a sustainable option for meat and milk production in the tropics. The association of grasses with legumes such as Leucaena leucocephala (leucaena) supply forage with high concentration of crude protein (Barros et al. 2012). There are reports in the scientific literature which show that intake of leucaena can result in good rates of growth in cattle (e.g. Shelton and Dalzell 2007); however the presence of the free amino acid mimosine and its metabolites (3,4-DHP and 2,3-DHP) in leucaena when the anaerobic bacteria Synergistes jonesii (Allison et al. 1992) is absent from the rumen, may induce subclinical toxicity in grazing ruminants (Graham 2007; Dalzell et al. 2012; Phaikaew et al. 2012). There are no reports in Mexico regarding the rate of growth of cattle grazing silvopastoral systems with leucaena. The aim of the present work was to evaluate the rate of growth of cattle grazing an association of Panicum maximum and leucaena compared to that of cattle fed a high grain ration (feedlot)

Urinary Excretion of Mimosine Metabolites by Hair Sheep Fed Foliage of \u3cem\u3eLeucaena leucocephala\u3c/em\u3e

Leucaena leucocephala is an adapted legume widely distributed in the tropical regions of Mexico. The high crude protein content of leucaena leaves renders it appropriate for ruminant feeding under commercial conditions. However, the foliage contains the non-protein amino acid mimosine, which, if consumed in high amounts, may induce toxicity in animals which have not previously consumed the legume or without microorganisms capable of degrading mimosine and its derivatives 2,3-DHP (dihydroxypyridine) and 3,4-DHP (Hammond 1995, Palmer et al. 2010, Dalzell et al. 2012). Barros-Rodríguez et al. (2012) found that dry matter intake and weight gain were reduced when sheep grazed paddocks with 55,000 plants of leucaena per hectare. Early work in Australia led to the isolation of Synergistes jonesii, an anaerobic bacterium able to degrade 3,4-DHP and 2,3-DHP to non-toxic compounds (Allison et al. 1992). In Mexico, the presence of this microorganism in the rumen has not yet been confirmed. Inoculation of non-accustomed animals with rumen liquor of ruminants adapted to the consumption of leucaena can reduce the impact of mimosine and its metabolites on animal health (Ghosh et al. 2009; Palmer et al. 2010). The aim of the present work was to evaluate the effects of transferring rumen liquor of cows adapted to the consumption of L. leucocephala to sheep without experience of consumption, on urinary excretion of 3.4-DHP and 2.3-DHP by means of a colorimetric technique

Vaccination of Gilthead Seabream After Continuous Xenoestrogen Oral Exposure Enhances the Gut Endobolome and Immune Status via GPER1

In fish culture settings, the exogenous input of steroids is a matter of concern. Recently, we unveiled that in the gilthead seabream (Sparus aurata), the G protein-coupled estrogen receptor agonist G-1 (G1) and the endocrine disruptor 17α-ethinylestradiol (EE2) are potent modulators in polyreactive antibody production. However, the integral role of the microbiota upon immunity and antibody processing in response to the effect of EE2 remains largely unexplored. Here, juvenile seabreams continuously exposed for 84 days to oral G1 or EE2 mixed in the fish food were intraperitoneally (i.p.) immune primed on day 42 with the model antigen keyhole limpet hemocyanin (KLH). A critical panel of systemic and mucosal immune markers, serum VTG, and humoral, enzymatic, and bacteriolytic activities were recorded and correlated with gut bacterial metagenomic analysis 1 day post-priming (dpp). Besides, at 15 dpp, animals received a boost to investigate the possible generation of specific anti-KLH antibodies at the systemic and mucosal interphases by the end of the trial. On day 43, EE2 but not G1 induced a significant shift in the serum VTG level of naive fish. Simultaneously, significant changes in some immune enzymatic activities in the serum and gut mucus of the EE2-treated group were recorded. In comparison, the vaccine priming immunization resulted in an attenuated profile of most enzymatic activities in the same group. The gut genes qPCR analysis exhibited a related pattern, only emphasized by a significant shift in the EE2 group’s il1b expression. The gut bacterial microbiome status underwent 16S rRNA dynamic changes in alpha diversity indices, only with the exposure to oral G1, supporting functional alterations on cellular processes, signaling, and lipid metabolism in the microbiota. By the same token, the immunization elevated the relative abundance of Fusobacteria only in the control group, while this phylum was depleted in both the treated groups. Remarkably, the immunization also promoted changes in the bacterial class Betaproteobacteria and the estrogen-associated genus Novosphingobium. Furthermore, systemic and mucosal KLH-specific immunoglobulin (Ig)M and IgT levels in the fully vaccinated fish showed only slight changes 84 days post-estrogenic oral administration. In summary, our results highlight the intrinsic relationship among estrogens, their associated receptors, and immunization in the ubiquitous fish immune regulation and the subtle but significant crosstalk with the gut endobolome.Versión del edito