Evolution. When did photosynthesis emerge on Earth?

Life began early in Earth's history, but it was the emergence of photosynthesis that allowed its proliferation across the planet, because it freed life from its sole dependence on abiotic chemical sources of reducing power. Des Marais discusses recent geological and molecular biological evidence, such as the paper by Xiong et al., that photosynthesis emerged at least 2,800 million years ago.     

Bovine Neonatal Pancytopenia is a heritable trait of the dam rather than the calf and correlates with the magnitude of vaccine induced maternal alloantibodies not the MHC haplotype

Bovine Neonatal Pancytopenia (BNP), a bleeding syndrome of neonatal calves, is caused by alloantibodies absorbed from the colostrum of particular cows. A commercial BVD vaccine is the likely source of alloantigens eliciting BNP associated alloantibodies. We hypothesized that the rare occurrence of BNP in calves born to vaccinated dams could be associated with genetic differences within dams and calves. We found that the development of BNP within calves was a heritable trait for dams, not for calves and had a high heritability of 19%. To elucidate which genes play a role in the development of BNP we sequenced candidate genes and characterized BNP alloantibodies. Alloantigens present in the vaccine have to be presented to the dam’s immune system via MHC class II, however sequencing of DRB3 showed no differences in MHC class II haplotype between BNP and non-BNP dams. MHC class I, a highly polymorphic alloantigen, is an important target of BNP alloantibodies. Using a novel sequence based MHC class I typing method, we found no association of BNP with MHC class I haplotype distribution in dams or calves. Alloantibodies were detected in both vaccinated BNP and non-BNP dams and we found no differences in alloantibody characteristics between these groups, but alloantibody levels were significantly higher in BNP dams. We concluded that the development of BNP in calves is a heritable trait of the dam rather than the calf and genetic differences between BNP and non-BNP dams are likely due to genes controlling the quantitative alloantibody response following vaccination.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0129-0) contains supplementary material, which is available to authorized users.     

Die potensiaal vir droëland aangeplante weiding in die vrystaatstreek

Uittreksel

Die uitbreidingspotensiaal van aangeplante weiding in die Vrystaatstreek is ondersoek. Die potensiaalomskrywing is gedoen aan die hand van klimatologiese oorwegings, beskikbaarheid van grond en die winsgewendheid van aangeplante weiding teen‐oor veld, mielie‐ en koringproduksie.

Die ondersoek toon aan dat daar aansienlike potensiaal vir die uitbreiding van aangeplante weiding bestaan sover dit die reenval en beskikbare grondoppervlakte aanbetref. Voorts is dit duidelik dat dit nie ekonomies geregverdig is om veld in ‘n redelike toestand vir aangeplante weiding om te ploeg nie. Dit word betwyfel of dit winsgewend is om marginale lande van koring‐ en mielieverbouing te onttrek en met aangeplante grasweidings te vestig waar gemiddelde en onder gemiddelde bestuur toegepas word. Droëlandlusern, benut deur wolskape en melkkoeie, en sorghums benut deur melkkoeie, blyk ekonomies geregverdig op marginale lande te wees.     

Effect of wilting on biochemical and microbiological changes in Kikuyu (Pennisetum clandestinum Hochst) silage

Small‐scale laboratory silos were used to study the fermentation process of Kikuyu (Pennisetum clandestinum Hochst) silage prepared from grass containing 25% and 40% dry matter. Silage made from grass containing 40% dry matter was found to be better preserved and of better quality than silage made from wetter grass. The better preservation and quality of the drier grass was reflected in the lower production of ammonia‐N (0,19 vs 0,26%) and total volatile fatty acids (5,48 vs 16,27%). Better quality was also reflected in the higher content of crude protein (16,3 vs 14,4%), true protein (9,0 vs 7,0%), residual total non‐structural carbohydrates (2,4 vs 2,3%), and in vitro dry matter digestibility (58,7 vs 55,2%). Both low and high dry matter silages had a low lactic‐acid content and high pH throughout fermentation. Both silages were of the acetate type.     

The use of vascular access ports in nonanesthetized green iguanas (iguana iguana) to collect baseline arterial blood gas parameters.

The green iguana, Iguana iguana, is used as a model in reptile anesthesia research because of its size, availability, and the body of knowledge characterizing its physiology. Arterial blood gas values in nonanesthetized green iguanas have not been determined because of the technical difficulty involved. Vascular access port (VAP) placement to facilitate blood sampling has been described in other species, but not lacertilians. This abstract describes the technique for placement of VAPs and the values for arterial blood gas parameters in seven 1 kg adult green iguanas. Using sterile technique, a 1.5 cm incision was made on the lateral side of the neck. Blunt dissection ventral to the external jugular vein revealed the internal and external carotid arteries near their bifurcation. The catheter was inserted into the internal carotid artery and then guided to the common carotid artery. The other end of the catheter was tunneled below the skin to a subcutaneous location, caudal‐dorsal to the iSPSilateral scapula. The skin was closed and the port was flushed twice a week with heparinized saline. Post‐operatively, the VAPs were well tolerated by the iguanas. Difficulties included port disconnection (n = 1), inability to aspirate blood after a few weeks (n = 2), and infection (n = 1). The iguanas were breathing room air prior to and during blood collection. From the five functional VAPs, the blood pH, PCO₂, PO₂, HCO^‐₃, and BE (measured at 37 °C) were 7.45 ± 0.06; 37.5 ± 7.0 mm Hg, 99.0 ±16.6 mm Hg, 25.4 ± 2.5 mmol L^–1, and 1.5 ±2.4 mmol L^–1 respectively (mean ± SD). VAPs can be successfully used to facilitate collection of arterial blood gas samples in green iguanas. These values are similar to those reported for most mammalian species. This technique should facilitate research in anesthesiology and respiratory physiology of iguanas and other lacertilians.     

大蒜素及其在畜禽生产中的应用进展

大蒜素是一种绿色环保药物和环保型绿色饲料添加剂,在畜禽养殖中应用十分广泛.本文综述了大蒜素的化学成分和理化特性、功能特点及其在畜禽养殖中的应用情况,并对其应用前景作了分析.     

磺胺嘧啶原料药生产设备的清洁验证

为验证磺胺嘧啶原料药生产设备清洁方法的有效性，从验证合格标准、取样回收率、检测方法、设备清洁后的贮存期限等方面对清洁方法进行了研究。试验证明，磺胺嘧啶原料药生产设备的清洁方法是有效的，按此方法清洁的设备其贮存期限为14天。     

A study of the pharmacokinetics and thromboxane inhibitory activity of a single intramuscular dose of carprofen as a means to establish its potential use as an analgesic drug in white rhinoceros

The alleviation of pain and prevention of suffering are key aspects of animal welfare. Unfortunately, analgesic drugs are not available for all species. White rhinoceros (Ceratotherium simum ), representing one of such species, which survive poaching attempts inflicted with severe facial injuries and gunshot wounds, nonetheless require analgesic support. To improve treatment conditions, this study explored the use of carprofen for the treatment of pain and inflammation in white rhinoceros. The pharmacokinetics of 1 mg/kg intramuscular carprofen was evaluated in six healthy white rhinoceros. The half‐life of λ_z and mean residence time was 105.71 ± 15.67 and 155.01 ± 22.46 hr, respectively. The area under the curve and the maximum carprofen concentration were 904.61 ± 110.78 μg ml^?1 hr^?1 and 5.77 ± 0.63 μg/ml, respectively. Plasma TXB ₂ inhibition demonstrated anti‐inflammatory properties and indicated that carprofen may be effective for a minimum of 48 hr in most animals. With its long half‐life further indicating that a single dose could be effective for several days, we suggest that carprofen may be a useful drug for the treatment of white rhinoceros.