Palms use a bluffing strategy to avoid seed predation by rats in Brazil.

The goal of this study was to ascertain why the production of variable seediness is advantageous for Attalea phalerata palms. Our hypothesis was that variation reduces seed predation by the spiny rats Thrichomys pachyurus and Clyomys laticeps. Although there is a positive correlation between endocarp size and number of seeds, endocarps sometimes contain more or fewer seeds than expected; palms bluff about the number of seed per endocarp. Therefore, rats do not know how many seeds an endocarp contains. To model rats? predating behavior, we applied Charnov?s Marginal Value Theorem. The model shows that rats attack endocarps only when the energy gain is higher than the energy available in the habitat. Hence, it is not advantageous to eat all the seeds inside an endocarp. This explains why 45 percent of forest endocarps and 35 percent of savanna endocarps were still viable after predation. We then applied the model to two simulated endocarp populations with less variability in the number of seeds per endocarp size and determined that viable diaspores after predation were reduced to 15 percent. With less variability, palms cannot bluff about the number of seeds inside endocarps and predators can predict accurately how many seeds they should try to eat. Uncertainty about the number of seeds diminished predation but gave selective advantage to multiseeded fruits. Therefore, the bluffing strategy would be evolutionarily stable only if it were counterbalanced by other forces. Otherwise, predators would win the bluffing game

Syk-dependent Phosphorylation of CLEC-2: A Novel Mechanism of Hem-Immunoreceptor Tyrosine-Based Activation Motif Signaling

The C-type lectin-like receptor CLEC-2 signals via phosphorylation of a single cytoplasmic YXXL sequence known as a hem-immunoreceptor tyrosine-based activation motif (hemITAM). In this study, we show that phosphorylation of CLEC-2 by the snake toxin rhodocytin is abolished in the absence of the tyrosine kinase Syk but is not altered in the absence of the major platelet Src family kinases, Fyn, Lyn, and Src, or the tyrosine phosphatase CD148, which regulates the basal activity of Src family kinases. Further, phosphorylation of CLEC-2 by rhodocytin is not altered in the presence of the Src family kinase inhibitor PP2, even though PLCγ2 phosphorylation and platelet activation are abolished. A similar dependence of phosphorylation of CLEC-2 on Syk is also seen in response to stimulation by an IgG mAb to CLEC-2, although interestingly CLEC-2 phosphorylation is also reduced in the absence of Lyn. These results provide the first definitive evidence that Syk mediates phosphorylation of the CLEC-2 hemITAM receptor with Src family kinases playing a critical role further downstream through the regulation of Syk and other effector proteins, providing a new paradigm in signaling by YXXL-containing receptors

Manejo das forrageiras dos gêneros Brachiaria e Panicum consorciadas com o milho em sistemas de Integração Lavoura-Pecuária.

bitstream/CNPMS-2010/22387/1/Circ-130.pd

Qualidade de silagens de híbridos de sorgo (Sorghum bicolor (L.) Moench) de portes baixo, médio e alto com diferentes proporções de colmo+folhas/panicula. 2. Avaliação do valor nutritivo.

O objetivo deste experimento foi avaliar a qualidade nutricional de silagens de sorgo de portes alto, médio e baixo, com diferentes combinações de colmo+folhas/panícula (100:00, 80:20, 60:40, 40:60, 20:80 e 00:100), por meio de análises laboratoriais. A planta inteira foi utilizada como controle. Os híbridos foram cultivados e ensilados aos 104 dias de idade em silos de laboratório de PVC, com 10 cm de diâmetro e 40 cm de comprimento (três repetições por tratamento). Os silos foram abertos aos 56 dias após a ensilagem. Os teores de proteína bruta e a digestibilidade in vitro da matéria seca, dos fenóis totais e dos constituintes da parede celular pelo método seqüencial foram determinados. As diferenças foram verificadas por intermédio do teste SNK para fenóis totais, sendo realizada análise de regressão para os demais resultados. Os valores de carboidratos solúveis do material original foram baixos para a maioria dos tratamentos, porém isto não prejudicou a fermentação, pois houve utilização de carboidratos adicionais, como hemicelulose e celulose, durante a ensilagem, sendo a queda destes maior na panícula e em colmo+folhas, respectivamente. Os valores de fenóis totais aumentaram com a ensilagem, apesar de não ter ocorrido redução concomitante na DIVMS. A inclusão de panícula na planta reduziu os teores dos constituintes da parede celular e aumentou os valores de DIVM, indicando que uma planta de sorgo para produzir silagem de boa qualidade deve ter, no mínimo, 40% de panícula e baixos teores de lignina, fenóis totais e constituintes da fibra

Experiences and perceptions of referrals to a community-based physical activity program for cancer survivors: a qualitative exploration

BACKGROUND: Physical activity rates in cancer survivors continue to be low despite the known benefits and availability of evidence-based programs. LIVESTRONG at the Y is a national community-based physical activity program offered cost-free to cancer survivors, though is underutilized. We explored perceptions and experiences of staff and participating survivors to better understand program awareness, referrals and participation. METHODS: LIVESTRONG at the Y program staff [directors (n = 16), instructors (n = 4)] and survivors (n = 8) from 8 United States YMCAs took part in 30-min semi-structured phone interviews between March-May 2019. Interviews were digitally recorded, transcribed, and evaluated using a thematic analysis approach. RESULTS: Program staff themes included: 1) Program awareness should be further developed for both the general public and medical providers; 2) Strong relationships with medical providers increased program referrals; 3) Electronic referral systems between providers and LIVESTRONG would help to streamline the referral process; and 4) Bi-directional communication between program staff and medical providers is key to providing patient progress updates. Survivor themes included: 1) Survivors trust their medical team and the information they provide about physical activity; 2) Providers need to incorporate an action plan and referrals for survivors to be active once treatments are completed; and 3) Personal experiences of those who participated in LIVESTRONG resonate with survivors and increase participation. CONCLUSIONS: LIVESTRONG staff reported the need for an integrated electronic referral system and bi-directional communication with providers about participant progress. Survivors want physical activity education, electronic referrals and follow-up from their healthcare team, coupled with peer support from other survivors. Cancer care provider knowledge and electronic referrals during and after treatment may expedite and increase participation in this community-based program

Women out, children out : the effect of female labor on portuguese preschool enrollment rates

This article tests whether Portuguese female activity rates have increased preschool enrollment rates. Particularly during the last 20 years, Portuguese women have assumed new roles in the marketplace and have become active workers outside of the home environment. This change has encouraged more sensible decisions with respect to preschool enrollment. Using cointegration techniques, we concluded that female activity rates and real income per capita caused a long-term increase in preschool enrollment rates. Although the percentage of agricultural gross value added to the gross domestic product and the number of preschool institutes were also found to be significant in the estimated vector error correction model, their causal relationship with preschool enrollment was only short term.COMPETE; QREN; FEDER; Fundação para a Ciência e a Tecnologia (FCT