A new analysis of the GJ581 extrasolar planetary system

We have done a new analysis of the available observations for the GJ581 exoplanetary system. Today this system is controversial due to choices that can be done in the orbital determination. The main ones are the ocurrence of aliases and the additional bodies - the planets f and g - announced in Vogt et al. 2010. Any dynamical study of exoplanets requires the good knowledge of the orbital elements and the investigations involving the planet g are particularly interesting, since this body would lie in the Habitable Zone (HZ) of the star GJ581. This region,for this system, is very attractive of the dynamical point of view due to several resonances of two and three bodies present there. In this work, we investigate the conditions under which the planet g may exist. We stress the fact that the planet g is intimately related with the orbital elements of the planet d; more precisely, we conclude that it is not possible to disconnect its existence from the determination of the eccentricity of the planet d. Concerning the planet f, we have found one solution with period $\approx 450$ days, but we are judicious about any affirmation concernig this body because its signal is in the threshold of detection and the high period is in a spectral region where the ocorruence of aliases is very common. Besides, we outline some dynamical features of the habitable zone with the dynamical map and point out the role played by some resonances laying there.Comment: 12 pages, 9 figure

Chirikov Diffusion in the Asteroidal Three-Body Resonance (5,-2,-2)

The theory of diffusion in many-dimensional Hamiltonian system is applied to asteroidal dynamics. The general formulations developed by Chirikov is applied to the Nesvorn\'{y}-Morbidelli analytic model of three-body (three-orbit) mean-motion resonances (Jupiter-Saturn-asteroid system). In particular, we investigate the diffusion \emph{along} and \emph{across} the separatrices of the (5,-2,-2) resonance of the (490) Veritas asteroidal family and their relationship to diffusion in semi-major axis and eccentricity. The estimations of diffusion were obtained using the Melnikov integral, a Hadjidemetriou-type sympletic map and numerical integrations for times up to $10^{8}$ years.Comment: 27 pages, 6 figure

Heat tolerance or extensive ability to acclimate

Heat thermal stress is a major concern environmental stress for dairy cattle, it limits animal growth, metabolism, and productivity. Taken this, the joint selection for productivity and adaptability should be considered in the actual dairy farms programs. This study aimed to evaluate the seasonal acclimatization process of cows with different milk yield potential. From a dairy farm located in Alentejo, Portugal, 13 Holstein-Friesian cows were chosen, 7 with high milk yield potential (HMP), ≥9,000 kg of milk at 305 days of lactation, and 6 with low milk yield potential (LMP), <9,000 kg. The trail was separated in 3 periods: (P1) Summer: acclimated cows in heat stress; (P2) Summer: acclimated cows in thermoneutrality; (P3) Winter: acclimated cows in thermoneutrality. Respiratory frequency (RF), rectal temperature (RT) milk composition and plasma triiodothyronine levels (T3) were collected. No differences were found in RF and RT between HMP and LMP cows in any of the periods. RF and RT values were significantly higher in P1 (64.13±12.78 mov./min. and 38.82±0.68 °C) than in P3 (36.13±7.67 mov./min. and 38.06±0.52 °C). Although, in P1, some HMP cows had RT values that indicated heat stress. We found no differences between groups in the lactose, protein, fat, β-Hydroxybutyric acid and somatic cell count. Urea was significantly higher in P1 in the HMP (293.62±35.97 mg/kg) than in LMP (253.69±33.81 mg/kg). T3, in both groups, gradually increased from P1 to P3 (P1-142.00±13.77; P2 – 157.36±10.72; P3 – 170.69±17.78 ng/dl). During summer, HMP had T3 values significantly lower than the LMP cows (P1: HMP-133.33±8.14, LMP-152.40±11.97; P2: HMP-146.50±7.64; LMP-170.40±12.29 ng/dl). Despite these results had revealed that HMP and LMP cows did not show significant differences in RF and RT variables, ongoing the acclimatization process, the HMP presented a lower metabolic activity as well a change in the nitrogen metabolic pathways

Evaluation of salivary proteins as potential biomarkers of milk production in hot climates

Evaluation of salivary proteins as potential biomarkers of milk production in hot climates Ana CAPM Geraldo1, Cristina Conceição 1,2, Liliana Cachucho2, Flávio Silva2, Catarina Matos2, Elsa Lamy1, Fernando Capela e Silva 1,3, and Alfredo Pereira 1,2 1 Institute of Mediterranean Agricultural and Environmental Sciences, University of Evora, Portugal; 2 Department of Zootechnics, University of Évora, Portugal; 3 Department of Biology, University of Evora, Portugal [email protected] Dairy cattle are particularly sensitive to high temperatures, lowering milk output as well as milk quality (fat, solid, lactose and protein). Given the trend of global warming, the joint selection for productivity and adaptability is an objective, i.e. greater heat loss without lowering the metabolism. So, to search and validate the xistence of non"invasive biomarkers that could allow selection of the animals best adapted is crucial to achieve such an objective. The interest of saliva as a source of biomarkers starts to increase in animal production. Salivary ortisol has been used in some studies, but it presents some limitations for thermal stress, which can be circumvent by salivary proteins. The hypothesis that cows presenting high potential for milk production under adverse thermal conditions also present differences in salivary protein profiles comparatively to the ones less productive, is actually being tested at ICAAM"University of Évora, Portugal, by our research team. The experiment was design to identify salivary proteins whose expression levels can be related to the potential for milk production under unfavourable thermal conditions. Twelve animals (6 high and 6 low milk potential production) were analysed for salivary protein composition at three different acclimation time points: first, during summer, under hot temperatures; second, under thermoneutrality; and third, during winter, under low temperatures. Whole saliva was collected directly from cow mouth, using cotton rolls (salivettes). At each time point, collection was performed in two different days, to avoid bias due to particular variations due to environment. One and two"dimensional electrophoresis are being performed to compare salivary proteomes from animals with different milk production potential, and to assess how differences between these groups are maintained through the different acclimation periods.COST FA1308- Dairy Care; ICAA

The acclimatisation process in dairy cows with different milk yield potential - searching for reliable biomarkers

In dairy cattle, heat thermal stress is a major concern environmental stress that limits animal growth, metabolism, and productivity. Facing global warming tendency, the current increased environmental temperatures, the joint selection for productivity and adaptability should be an objective for dairy farms. This study aimed to evaluate the acclimatisation process of cows with different milk yield potential during summer and winter periods. 13 Holstein-Friesian cows were chosen from a dairy farm located in Alentejo, Portugal, 7 of those with high milk yield potential (HMP) and 6 with low milk yield potential (LMP). All cows were evaluated during summer and winter periods in respiratory frequency (RF), sweating rate (SR) and rectal temperature (RT) as well as milk, blood and saliva parameters. RF, SR and RT values were significantly higher in summer (64.13±12.78 mov./min., 76,89±46.77 g/m2 /h and 38.82±0.68 °C) than in winter (36.13±7.67 mov./min., 24.69±7.30 g/m2 /h and 38.06±0.52 °C), without differences between the two groups (HMP and LMP). Haematocrit and triiodothyronine levels were significantly lower in summer (23.80±9.39 % and 142.00±13.77 ng/dL) than in winter (30.70±5.00 % and 170.69±17.78 ng/dL) for both groups. However, in summer, HMP cows presented triiodothyronine blood concentrations (133.33±8.14 ng/dL) significantly lower than the LMP (152.40±11.97 ng/dL). Concerning salivary parameters, only HMP cows showed higher HSP70 concentrations during summer, without major changes in cortisol. Regarding milk analysis, urea levels were the only milk compound significantly different between groups (P<0.05): during summer the HMP group (293.62±35.97 mg/kg) had milk urea levels higher than LMP (253.69±33.81 mg/kg). These results showed that although HMP cows did not differed significantly in the first responses to heat (RF, SR and RT) from LMP cows, with the acclimatisation process, they showed higher physiological modifications, decreasing the metabolism, increasing HSP expression and changing milk composition. These results seem to indicate the potential use of HSP70 in saliva and urea in milk as potential biomarkers of heat stress

The 24-hour serum profiles of bone markers in healthy older men and women

Bone and mineral researc