208 research outputs found

    Intraspecific differences in seed dispersal caused by differences in social rank and mediated by food availability

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    We use individual-based information on the behavior of wild female Japanese macaques in two consecutive years with different food availability (nut-rich vs. nut-poor) to test effects of dominance rank and nut fruiting on seed dispersal parameters. We predicted that social rank would affect dispersal (1) quantity, (2) quality, (3) species richness, and (4) percentage of berries in the diet in the nut-poor year, while these differences would disappear in the nut-rich year. We found seeds of nine fleshy-fruited plant species in the feces of the monkeys. The frequency of seed occurrence for two plant species (Viburnum dilatatum and Rosa multiflora) showed an interaction between dominance ranks and years; in the nut-poor year V. dilatatum seeds were more abundant among dominant females and R. multiflora among subordinates, while such inter-rank differences disappeared in the nut-rich year. Similarly, the intact ratio of V. dilatatum seeds was lower for dominants in the nut-poor year, while inter-rank variations disappeared in the nut-rich year. Finally, percentage of berries in diet and seed richness showed no inter-annual nor inter-rank variations. Our study highlights that differences in individuals’ social rank lead to within-group variation in seed dispersal services and that these differences are dependent on nut availability

    Studying the quantity component of seed dispersal effectiveness from exclosure treatments and camera trapping

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    The quantity component of effectiveness of seed dispersal by animals is determined by two events: fruit removal (intensity of the interaction) and animal visitation to the plant (frequency of interactions). Considering dispersal of Prosopis flexuosa seeds as case study, this work aimed at investigating the strengths and weaknesses of the two methods for assessing the quantity component of seed dispersal effectiveness: exclosures and camera traps. Prosopis fruits were offered for 48 hr. Exclosure treatments were performed using two types of wire-screen cages, allowing access to ants (“closed exclosure”) and to small mammals up to 100 g (“open to small mammals”), and a treatment without exclosure (“open to all removers”). The camera trapping experiment was carried out using vertically oriented cameras placed at approximately 1.80 m height and focused on the fruits. The cameras were set in “motion detect mode,” taking series of three consecutive photographs. The exclosures largely allowed estimation of fruit removal by size-based groups of animals, but did not provide information on species identity. In contrast, camera traps were able to identify all visitors to species level and could not only determine the number of visits by each species but also the proportion of visits, which resulted in removal of fruits. Camera trapping allowed discriminating among small mammals playing different roles, without underestimating fruit removal by scatter-hoarding species. The quality of estimation of the quantity component of seed dispersal is remarkably better when the camera trapping method is applied. Additional information obtained, such as activity patterns of visitors, can contribute to a better understanding of the seed dispersal process.Fil: Campos, Claudia Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Velez, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Miguel, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Papú, Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Cona, Monica Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin

    Diffusion-weighted imaging with color-coded images: towards a reduction in reading time while keeping a similar accuracy

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    The aim of this study was to develop a diagnostic tool capable of providing diffusion and apparent diffusion coefficient (ADC) map information in a single color-coded image and to assess the performance of color-coded images compared with their corresponding diffusion and ADC map. The institutional review board approved this retrospective study, which sequentially enrolled 36 head MRI scans. Diffusion-weighted images (DWI) and ADC maps were compared to their corresponding color-coded images. Four raters had their interobserver agreement measured for both conventional (DWI) and color-coded images. Differences between conventional and color-coded images were also estimated for each of the 4 raters. Cohen's kappa and percent agreement were used. Also, paired-samples t-test was used to compare reading time for rater 1. Conventional and color-coded images had substantial or almost perfect agreement for all raters. Mean reading time of rater 1 was 47.4 seconds for DWI and 27.9 seconds for color-coded images (P = .00007). These findings are important because they support the role of color-coded images as being equivalent to that of the conventional DWI in terms of diagnostic capability. Reduction in reading time (which makes the reading easier) is also demonstrated for one rater in this study.Departamento de Diagnóstico por Imagem da Escola Paulista de Medicina da UNIFESP, Rua Napoleão de Barros, 800 Vila Clementino, 04024-002 São Paulo, SP, BrazilDepartamento de Diagnóstico por Imagem da Escola Paulista de Medicina da UNIFESP, Rua Napoleão de Barros, 800 Vila Clementino, 04024-002 São Paulo, SP, BrazilWeb of Scienc

    Explorando os efeitos da sincronização do segundo estro e flushing alimentar sobre a incidência de cistos ovarianos em marrãs utilizando gonadotrofinas exógenas

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    Estrus stimulation by exogenous gonadotropins (EG) in association with dietary flushing is an important tool for the improvement of gilt reproductive performance. However, there is evidence associating both flushing and EG with a disturbance in the endocrine balance that could lead to increased ovarian cysts. The aim of this study was to evaluate whether flushing or EG might affect the ovulation rate and the incidence of ovarian cysts. Seventy-one gilts were randomly distributed into 2x2 factorial design with four treatments: flushing and hormone (wFwH); no flushing and hormone (nFwH); flushing without hormone (wFnH); and neither flushing nor hormone (nFnH). Gilts were slaughtered for macroscopic and histopathological ovary examination approximately five days after AI. The characterization of these cysts was performed by optical microscopy in the following: follicular cysts (FC), luteinized cysts (LC) or cystic corpora lutea (CCL). The number of ovulations did not differ between treatments. There was no interaction between the factors in any analyzed variable. The frequency of gilts with CCL and LC was not affected by flushing and EG. No difference was found in the incidence of FC, with 12.5% and 5.88% in gilts from wFwH and nFwH treatments, respectively. There were no differences in the proportion of CCL between FC and LC (9.85 vs. 4.22 and 4.22%, respectively). In conclusion, the use of exogenous gonadotropins for second estrus synchronization in gilts, either alone or in association with dietary flushing, does not increase the incidence of ovarian cysts, nor does it decrease the ovulation rate.A estimulação do estro por gonadotrofinas exógenas (GE) associada ao flushing alimentar é uma ferramenta importante na melhoria do desempenho reprodutivo de marrãs. Contudo, há evidência da associação do flushing com GE levando ao desequilíbrio no sistema endócrino que poderia levar ao aumento de cistos ovarianos. O objetivo deste estudo foi avaliar se o flushing ou GE pode afetar a taxa de ovulação e a incidência de cistos ovarianos. Setenta e uma marrãs foram distribuídas aleatoriamente em arranjo fatorial 2x2 com quatro tratamentos: flushing e hormônio (cFcH); sem flushing e com hormônio (sFcH); com flushing e sem hormônio (cFsH) e sem flushing e hormônio (sFsH). Marrãs foram abatidas para exame macroscópico e histopatológico dos ovários, aproximadamente cinco dias após IA. A caracterização desses cistos foi realizada por microscopia óptica: cistos foliculares (CF), cistos luteinizados (CL) ou corpos lúteos císticos (CCL). O número de ovulações não diferiu entre os tratamentos. Não houve interação entre os fatores em qualquer variável analisada. A frequência de leitoas com CCL e CL não foi afetada pelo flushing e GE. Não houve diferença na incidência de CF, com 12,5% e 5,88 % em leitoas dos tratamentos cFcH e sFcH, respectivamente. Não foram obtidas diferenças na proporção de CCL entre CF e CL (9,85 vs. 4,22 e 4,22%, respectivamente). Em conclusão, a utilização de gonadotrofinas exógenas para sincronização do segundo estro de marrãs, isoladamente ou em associação com o flushing, não aumenta a incidência de cistos ovarianos e não diminui a taxa de ovulação

    Estudo da interação da radiação de microondas com sistemas biológicos e aplicações

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    -O objetivo do presente projeto é estudar os possíveis mecanismos da interação de radiação de microondas de baixa intensidade em sistemas biológicos. Realizamos estudos em alguns tecidos vegetais e animais. Com relação ao tecido vegetal estudamos a taxa de crescimento da semente de milho e feijão expostos a radiação de microondas. A faixa de frequencia utilizada nas sementes foi de 10GHz e com uma intensidade em torno de 0,003 microwatts por centímetro quadrado. Pode-se observar um aumento da taxa de germinação nas sementes expostas à radiação de microondas quando comparada com o controle. Também estão sendo realizados experimentos de radiação de microondas proveniente de um telefone celular (GSM 1.8GHz) em ratos. As análises estão focadas nas alterações das proteínas de stress encontradas na glandula pineal dos ratos. Sabe-se que a via de sinalização de MAPKs é a mais importante na regulação transcricional induzida por estímulo extracelular (YOON e SEGER, 2006). ERK1 e ERK2 estão entre as proteínas que atuam nesta via de sinalização, sendo que culturas de Células Rat1 e HeLa apresentaram aumento da expressão de ERK1 e ERK2 (in vitro) quando expostas à radiação de aparelhos celulares (FRIENDMAN et al. 2007). Deste modo, nossos estudos visam avaliar a influência da radiação emitida por celulares sobre ERK1 e 2, além de outras proteínas, como AKT (que atua no ciclo celular), PKC (relacionada com o desenvolvimento de câncer) e TH (muito importante no sistema nervoso central). Para o presente estudo foi desenvolvido no Laboratório de Óptica da UFJF um dispositivo capaz de realizar ligações de um aparelho de celular sem influenciar na radiação emitida. O equipamento é controlado por um micorcontrolador PIC12F675 e usa um motor de passo PM55L-048 para pressionar as teclas

    The greater occipital nerve and its spinal and brainstem afferent projections. A stereological and tract-tracing study in the rat.

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    The neuromodulation of the greater occipital nerve (GON) has proved effective to treat chronic refractory neurovascular headaches, in particular migraine and cluster headache. Moreover, animal studies have shown convergence of cervical and trigeminal afferents on the same territories of the upper cervical and lower medullary dorsal horn (DH), the so-called trigeminocervical complex (TCC), and recent studies in rat models of migraine and craniofacial neuropathy have shown that GON block or stimulation alter nociceptive processing in TCC. The present study examines in detail the anatomy of GON and its central projections in the rat applying different tracers to the nerve and quantifying its ultrastructure, the ganglion neurons subserving GON, and their innervation territories in the spinal cord and brainstem. With considerable intersubject variability in size, GON contains on average 900 myelinated and 3,300 unmyelinated axons, more than 90% of which emerge from C2 ganglion neurons. Unmyelinated afferents from GON innervates exclusively laminae I-II of the lateral DH, mostly extending along segments C2-3 . Myelinated fibers distribute mainly in laminae I and III-V of the lateral DH between C1 and C6 and, with different terminal patterns, in medial parts of the DH at upper cervical segments, and ventrolateral rostral cuneate, paratrigeminal, and marginal part of the spinal caudal and interpolar nuclei. Sparse projections also appear in other locations nearby. These findings will help to better understand the bases of sensory convergence on spinomedullary systems, a critical pathophysiological factor for pain referral and spread in severe painful craniofacial disorders.pre-print659 K
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