Toxin production by Rosellinia desmazieresii (Berk. & Br.) Sacc.

Damage symptoms, were expressed on detached shoots of Salix repens within 24 hours of exposure to toxin preparations from culture filtrates of Rosellina desmazieresii. Many of these symptoms, which resembled those observed on diseased plants, could also be obtained in the test system by exposure to cytochalasin E solutions. This toxic compound is produced by R. desmazieresii and may be important in symptom development, since culture filtrate preparations from isolates producing little cytochalasin E induced few symptoms. Toxin preparations from R. desmazieresii induced damage on detached shoots of several woody species, including both hosts and non-hosts of this fungus.     

Ubiquitin-like protein involved in the proteasome pathway of Mycobacterium tuberculosis

The protein modifier ubiquitin is a signal for proteasome-mediated degradation in eukaryotes. Proteasome-bearing prokaryotes have been thought to degrade proteins via a ubiquitin-independent pathway. We have identified a prokaryotic ubiquitin-like protein, Pup (Rv2111c), which was specifically conjugated to proteasome substrates in the pathogen Mycobacterium tuberculosis. Pupylation occurred on lysines and required proteasome accessory factor A (PafA). In a pafA mutant, pupylated proteins were absent and substrates accumulated, thereby connecting pupylation with degradation. Although analogous to ubiquitylation, pupylation appears to proceed by a different chemistry. Thus, like eukaryotes, bacteria may use a small-protein modifier to control protein stability.     

Voyager detection of nonthermal radio emission from saturn

The planetary radio astronomy experiment on board the Voyager spacecraft has detected bursts of nonthermal radio noise from Saturn occurring near 200 kilohertz, with a peak flux density comparable to higher frequency Jovian emissions. The radiation is right-hand polarized and is most likely emitted in the extraordinary magnetoionic mode from Saturn's northern hemisphere. Modulation that is consistent with a planetary rotation period of 10 hours 39.9 minutes is apparent in the data.     

Intercontinental spread of pyrimethamine-resistant malaria

Here we present molecular evidence demonstrating that malaria parasites bearing high-level pyrimethamine resistance originally arrived in Africa from southeast Asia. The resistance alleles carried by these migrants are now spreading across Africa at an alarming rate, signaling the end of affordable malaria treatment and presenting sub-Saharan Africa with a public health crisis.     

Calcium and bicarbonate effects on the growth and nutrient uptake of burley tobacco seedlings: Hydroponic culture 1

Abstract

In soilless production systems, water quality can have a major impact on the growth of plants. It has become evident that moderately alkaline water is a problem for tobacco transplant growers in some regions of Kentucky. To determine the level of bicarbonate (HCO₃ ^?) alkalinity, which is detrimental to burley tobacco transplants, and to better understand the effect of calcium (Ca) and the interaction of HCO₃ ^? and Ca on the growth of burley tobacco transplants grown in a float system, three levels of CaCl₂ (25,75, and 125 mg L^?1 Ca⁺⁺) in factorial combination with five levels of HCO₃ ^? (0, 122, 244, 366, and 488 mg HCO₃ ^?L^?1) were tested in nutrient solution culture. Four‐week‐old burley tobacco (Nicotiana tabacum L. var. KY‐907) seedlings were transplanted to 18‐L containers filled with aerated Hoagland's solution with the different levels of calcium and HCO₃ ^? for two weeks. High HCC₃ ^? alkalinity caused root system damage and plant growth inhibition, but did not induce iron (Fe) chlorosis. A significantly lower concentration of Zinc (Zn) was measured in the shoots as HCO₃ ^? levels in solution increased. In the presence of high calcium, plant growth was not significantly improved. No significant interaction of HCO₃ ^? and Ca on growth or nutrient uptake was observed in this study.     

Identification of the DDAH2 Protein in Pig Reproductive Tract Mucus: A Putative Oestrus Detection Marker

Precisely detecting oestrus is important for artificial insemination. The aims of this study were to identify oestrus‐specific sow mucus proteins to determine the optimal time for artificial insemination. The proestrous‐ and oestrous‐stage mucus proteins were purified and analysed with proteomic tools such as two‐dimensional gel electrophoresis and matrix‐assisted laser desorption/ionization–time‐of‐flight analyses. Among the differentially expressed proteins, the dimethylarginine dimethylaminohydrolase 2 (DDAH2) protein showed a 3.6‐fold increase during the proestrous stage compared to that during the oestrous stage. A western immunoblot study revealed that two of three sow mucus samples clearly showed negative anti‐DDAH2 antibody activity during the oestrous stage. This study demonstrated that the pig DDAH2 mucus protein exists during the proestrous stage, but not during the oestrous stage, suggesting that mucus DDAH2 could be useful as an oestrus detection marker.