Pollen Viability and Seed Setting in Egyptian Clover Under Open and Caged Conditions

Grown on an area of about 200Kha annually, Egyptian clover (berseem) is the most important winter forage crop of Punjab. Its seed production is erratic due to several factors, including high temperature during flowering, which may affect pollen viability and the role of insect pollinators. Hence, berseem seed production is an entomological problem as much as a botanical one. We studied pollen viability under open and caged conditions, and the role of honeybees in seed setting

Seroprevalenceof HBs Ag and HCV in Healthy Blood Donors at a Tertiary Care Hospital in India

ABSTRACT Hepatitis B and hepatitis C threatens safety of the recipients and the community as a whole and are subject of real concern worldwide. To assess the seroprevalence of HBV and HCV among blood donors at a tertiary care hospital-based blood bank in Punjab.7000 blood donors (5450 voluntary and 1550 replacement donors) were studied. All the blood donors were screened for HBsAg and anti-HCV antibodies (third generation ELISA). Seroprevalence of HBsAg and HCV were 0.91% and 0.83% respectively. Seropositivitywas higher among replacement donors than voluntary donors in HBsAg (1.39% vs. 0.79%) and HCV (1.22% vs. 0.72%). Seroprevalence was more in age group 31-40 years and higher in rural area donors. The incidence decreased in repeat donors. Prevalence of HBsAg was higherthan anti HCV. Stringent measures need to be taken including dissemination of information andvigilant donor screening, screening of blood unit with sensitive techniques like NAT,inclusion of antibody to hepatitis B core antigen. Key words: Blood donors, HBsAg, anti-HCV, voluntary donor, replacement donor. Key message: Repeat voluntary donors are safest and inclusion of sensitive techniques like NAT, antibodies to HBcAg and HCV RNA for donor screening will improve blood safety further. Educate rural masses about the prevention of viral diseases

Enzymes from Fungal and Plant Origin Required for Chemical Diversification of Insecticidal Loline Alkaloids in Grass-\u3cem\u3eEpichloë\u3c/em\u3e Symbiota

The lolines are a class of bioprotective alkaloids that are produced by Epichloë species, fungal endophytes of grasses. These alkaloids are saturated 1-aminopyrrolizidines with a C2 to C7 ether bridge, and are structurally differentiated by the various modifications of the 1-amino group: -NH2 (norloline), -NHCH3 (loline), -N(CH3)2 (N-methylloline), -N(CH3)Ac (N-acetylloline), -NHAc (N-acetylnorloline), and -N(CH3)CHO (N-formylloline). Other than the LolP cytochrome P450, which is required for conversion of N-methylloline to N-formylloline, the enzymatic steps for loline diversification have not yet been established. Through isotopic labeling, we determined that N-acetylnorloline is the first fully cyclized loline alkaloid, implying that deacetylation, methylation, and acetylation steps are all involved in loline alkaloid diversification. Two genes of the loline alkaloid biosynthesis (LOL) gene cluster, lolN and lolM, were predicted to encode an N-acetamidase (deacetylase) and a methyltransferase, respectively. A knockout strain lacking both lolN and lolM stopped the biosynthesis at N-acetylnorloline, and complementation with the two wild-type genes restored production of N-formylloline and N-acetylloline. These results indicated that lolN and lolM are required in the steps from N-acetylnorloline to other lolines. The function of LolM as an N-methyltransferase was confirmed by its heterologous expression in yeast resulting in conversion of norloline to loline, and of loline to N-methylloline. One of the more abundant lolines, N-acetylloline, was observed in some but not all plants with symbiotic Epichloë siegelii, and when provided with exogenous loline, asymbiotic meadow fescue (Lolium pratense) plants produced N-acetylloline, suggesting that a plant acetyltransferase catalyzes N-acetylloline formation. We conclude that although most loline alkaloid biosynthesis reactions are catalyzed by fungal enzymes, both fungal and plant enzymes are responsible for the chemical diversification steps in symbio

Theoretical prediction and experimental study of a ferromagnetic shape memory alloy: Ga_2MnNi

We predict the existence of a new ferromagnetic shape memory alloy Ga_2MnNi using density functional theory. The martensitic start temperature (T_M) is found to be approximately proportional to the stabilization energy of the martensitic phase (deltaE_tot) for different shape memory alloys. Experimental studies performed to verify the theoretical results show that Ga_2MnNi is ferromagnetic at room temperature and the T_M and T_C are 780K and 330K, respectively. Both from theory and experiment, the martensitic transition is found to be volume conserving that is indicative of shape memory behavior.Comment: 11 pages, 3 figure

Использование метода моделирования ситуаций при обучении студентов вуза английскому языку

В статье описывается опыт проведения занятий по английскому языку у студентов второго курса направления "Горное дело" с использованием современного активного метода обучения case study. Отмечаются преимущества применения технологии моделирования ситуации при преподавании профессионально-ориентированного курса английского языка в вузе