utjecaj sezonskih promjena tropske klime na reprodukcijske pokazatelje i hormonski status jaraca sanske pasmine

This study evaluated the effects different seasons (rainy, rainy-dry transition, dry, dry-rainy transition) throughout the year on the reproduction and endocrine profile of Saanen bucks reared in a tropical climate. During these seasons environmental data were recorded (ambient temperature and relative air humidity) to calculate the temperature and humidity index. Reproductive parameters were also evaluated in the same periods to check seasonal variations, wherey semen was collected twice a month from nine Saanen bucks using an artificial vagina. Furthermore, scrotal circumference, scrotal surface temperature and serum levels of testosterone, triiodothyronine (T3), thyroxine (T4) and cortisol were measured. The climate parameters influenced the reproductive parameters, mainly during the dry period, when higher values of ambient temperature reduced sperm quality, however, scrotal circumference and surface temperature, as well as serum levels of testosterone increased. In conclusion, Saanen bucks reared in a tropical climate are subject to heat stress, evinced by transient seasonal variations in reproductive parameters, where the first season is the most favorable to reproduction.U ovom je radu istražen utjecaj različitih sezona (kišna, prijelaz iz kišne u suhu, suha, prijelaz iz suhe u kišnu) tijekom godine na reprodukcijski i endokrini status jaraca sanske pasmine uzgojenih u tropskoj klimi. Zabilježeni su podaci iz okoliša (temperatura i relativna vlažnost zraka) za vrijeme različitih sezona kako bi se izračunao indeks topline. Za ista su razdoblja procijenjeni reprodukcijski pokazatelji kako bi se istražile njihove sezonske varijacije u koju je svrhu od 9 jaraca sanske pasmine primjenom umjetne vagine, prikupljano sjeme dva puta mjesečno. Osim toga mjereni su obujam skrotuma, temperatura površine skrotuma te razina testosterona, trijodotironina (T3), tiroksina (T4) i kortizola u serumu. Klimatski uvjeti su utjecali na reprodukcijske pokazatelje, najviše za vrijeme suhog razdoblja, kad veće vrijednosti temperature okoliša smanjuju kvalitetu sjemena jaraca. Obujam i temperatura površine skrotuma, kao i serumska razina testosterona, u navedenoj sezoni su povećani. Zaključeno je da su sanski jarci uzgojeni u tropskoj klimi pod utjecajem toplinskog stresa, što se vidi iz sezonskih varijacija njihovih reprodukcijskih pokazatelja, pri čemu je kišna sezona najpovoljnija za reprodukciju

Rigorous Formulation of Duality in Gravitational Theories

In this paper we evince a rigorous formulation of duality in gravitational theories where an Einstein like equation is valid, by providing the conditions under which the Hodge duals (with respect to the metric tensor g) of T^a and R_b^a may be considered as the torsion and curvature 2-forms associated with a connection D', part of a Riemann-Cartan structure (M,g',D'), in the cases g = g' and g does not equal g', once T^a and R_b^a are the torsion and curvature 2-forms associated with a connection D part of a Riemann-Cartan structure (M,g,D). A new form for the Einstein equation involving the dual of the Riemann tensor of D is also provided, and the result is compared with others appearing in the literature.Comment: 15 page

Hydroxamic acid derivatives: a promising scaffold for rational compound optimization in Chagas disease.

This work describes the antitrypanocidal activity of two hydroxamic acid derivatives containing o-ethoxy (HAD1) and p-ethoxy (HAD2) as substituent in the aromatic ring linked to the isoxazoline ring. HAD1 and HAD2 induced a significant reduction in the number of intracellular parasites and consequently showed activity on the multiplication of the parasite. Treatment of cardiomyocytes and macrophages with the compounds revealed no significant loss in cell viability. Ultrastructural alterations after treatment of cardiomyocytes or macrophages infected by Trypanosoma cruzi with the IC50 value of HAD1 revealed alterations to amastigotes, showing initial damage seen as swelling of the kinetoplast. This gave a good indication of the ability of the drug to permeate through the host cell membrane as well as its selectivity to the parasite target. Both compounds HAD1 and 2 were able to reduce the cysteine peptidases and decrease the activity of metallopeptidases

Natural deep eutectic solvent (NADES)-based blueberry extracts protect against ethanol-induced gastric ulcer in rats.

Blueberry is a polyphenol-rich fruit bearing great bioactive potential. Natural deep eutectic solvents (NADES) emerged as putatively biocompatible solvents that could substitute for toxic organic solvents in the extraction of fruit phenolic compounds for developing nutraceuticals or functional foods. Therefore, the aim of this study was to investigate the gastroprotective effects and the biocompatibility of a blueberry crude extract (CE) obtained using NADES and of the extract fractions (anthocyanin-rich fraction ? ARF; non-anthocyanin phenolic fraction - NAPF) in a model of ethanol-induced gastric ulcer in rats. CE was the NADES-containing, ready-to-use extract that was obtained using choline chloride:glycerol:citric acid NADES (0.5:2:0.5 M ratio). ARF and NAPF were the NADES-free fractions obtained by solid phase purification of CE and were investigated to identify the bioactive fraction responsible for the effects of CE. Animals were treated for 14 days with water, NADES vehicle, CE, ARF, NAPF or lansoprazole (intragastric) and then received ethanol to induce gastric ulcer. CE decreased ulcer index and preserved the integrity of gastric mucosa. The pretreatment with CE or ARF reduced glutathione depletion and the inflammatory response. All treatments, including NADES vehicle reduced protein oxidation and nitric oxide overproduction in ethanol-treated rats. Additionally, ARF increased short-chain fatty acids in feces. These findings suggest that NADES can be used to obtain biocompatible extracts of blueberry that exhibit gastroprotective effects with no need of solvent removal. The gastroprotective effects were mainly associated to ARF but NAPF and even NADES vehicle also contributed to some protective effects

As contradições do processo de desenvolvimento agrícola na Transamazônica.

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