A physical mechanism for North Atlantic SST influence on the Indian summer monsoon

A link between the Atlantic Multidecadal Oscillation (AMO) and multidecadal variability of the Indian summer monsoon rainfall is unraveled and a long sought physical mechanism linking Atlantic climate and monsoon has been identified. The AMO produces persistent weakening (strengthening) of the meridional gradient of tropospheric temperature (TT) by setting up negative (positive) TT anomaly over Eurasia during northern late summer/autumn resulting in early (late) withdrawal of the south west monsoon and persistent decrease (increase) of seasonal monsoon rainfall. On inter-annual time scales, strong North Atlantic Oscillation (NAO) or North Annular mode (NAM) influences the monsoon by producing similar TT anomaly over Eurasia. The AMO achieves the interdecadal modulation of the monsoon by modulating the frequency of occurrence of strong NAO/NAM events. This mechanism also provides a basis for explaining the observed teleconnection between North Atlantic temperature and the Asian monsoon in paleoclimatic proxies

Correlations between biometrical characters in vanilla (Vanilla planifolia Andrews)

A study was undertaken to fmd out the extent of association among growth attributes of vanilla (Vanilla planifolia) and to develop a model for determination of vine length based on biometrical observations. The characters, number of nodes, number of leaves and internodal length were significantly and positively correlated with vine length. The multiple regression equation derived exhibited a precision of 82.5 per cent. &nbsp

Correlations between biometrical characters in vanilla (Vanilla planifolia Andrews)

A study was undertaken to fmd out the extent of association among growth attributes of vanilla (Vanilla planifolia) and to develop a model for determination of vine length based on biometrical observations. The characters, number of nodes, number of leaves and internodal length were significantly and positively correlated with vine length. The multiple regression equation derived exhibited a precision of 82.5 per cent. &nbsp

Performance of turmeric (Curcuma longa L.) varieties in lower Pulney hills of Tamil Nadu, India

Eight turmeric (Curcuma longa) varieties were evaluated under rainfed conditions for two crop seasons at lower Pulney hills, Tamil Nadu, India. The varieties differed among themselves with regard to yield and growth characters such as plant height, number of tillers per plant, leaves per tiller, leaflength and breadth and curing percentage. Suvarna (PCT-8) had maximum number of tillers per plant but was inferior to others in relation to other growth traits. The highest yield (t/ha - fresh rhizomes) was recorded in BSR-l (20.88), followed by Suvarna (19.32) and Suroma (19.04). &nbsp

Yield forecasting in cardamom (Elettaria cardamomum Maton) plantations under intensive management

A study was undertaken to develop a model for forecasting the yield in cardamom plantations under intensive management. Thirteen biometrical characters namely tillers per clump, tiller height leaves per tiller, vegetative buds per clump, bearing tillers per clump, panicles per clump, panicle length, racemes per panicle, capsules per raceme, seeds per capsule, leaf length, leaf breadth and recovery percentage were chosen as explana tory variables and they exhibited a precision of about 82%. Step down regression resulted in the retention of only four characters namely, panicles per clump, racemes per panicle, capsules per raceme and leaf breadth with which yield can be estimated with around 77% precision. &nbsp

Factor analysis in cardamom (Elettaria cardamomum Maton)

A pooled factor analysis of 17 variables representing morphological, yield contributing and qualitative characters of 90 genotypes of cardamom (Elettaria cardamomum) was carried out at Myladumpara (Kerala), for identifying marker characters which accommodate the inheritance of associated characters. Among the 17 characters subjected to the analysis, 6 factors were identified as having maximum influence on growth, yield and quality of cardamom. Among the six factors identified, three factors controlled yield and yield contributing characters, two factors controlled qualitative characters and one factor controlled growth characters. The characters identified with maximum factor loadings in each group include bearing tillers clump-I, seeds capsule-I, internodal length, racemes panicle-I, leaf breadth and capsules (dry) kg-I. The six principal components or factors accounted for 78.09% of the total variance. &nbsp

Natural fruit set in Vanilla wightiana Lindl., an endangered species from Andhra Pradesh, India

Vanilla wightiana Lindt, described as an extremely endangered wild species, occurs in the Eastern Ghat forest ranges of East Godavari District of Andhra Pradesh, India. &nbsp

Nitric oxide from inflammatory origin impairs neural stem cell proliferation by inhibiting epidermal growth factor receptor signaling

Neuroinflammation is characterized by activation of microglial cells, followed by production of nitric oxide (NO), which may have different outcomes on neurogenesis, favoring or inhibiting this process. In the present study, we investigated how the inflammatory mediator NO can affect proliferation of neural stem cells (NSCs), and explored possible mechanisms underlying this effect. We investigated which mechanisms are involved in the regulation of NSC proliferation following treatment with an inflammatory stimulus (lipopolysaccharide plus IFN-gamma), using a culture system of subventricular zone (SVZ)-derived NSCs mixed with microglia cells obtained from wild-type mice (iNOS(+/+)) or from iNOS knockout mice (iNOS(-/-)). We found an impairment of NSC cell proliferation in iNOS(+/+) mixed cultures, which was not observed in iNOS(-/-) mixed cultures. Furthermore, the increased release of NO by activated iNOS(+/+) microglial cells decreased the activation of the ERK/MAPK signaling pathway, which was concomitant with an enhanced nitration of the EGF receptor. Preventing nitrogen reactive species formation with MnTBAP, a scavenger of peroxynitrite (ONOO-), or using the ONOO- degradation catalyst FeTMPyP cell proliferation and ERK signaling were restored to basal levels in iNOS(+/+) mixed cultures. Moreover, exposure to the NO donor NOC-18 (100 mu M), for 48 h, inhibited SVZ-derived NSC proliferation. Regarding the antiproliferative effect of NO, we found that NOC-18 caused the impairment of signaling through the ERK/MAPK pathway, which may be related to increased nitration of the EGF receptor in NSC. Using MnTBAP nitration was prevented, maintaining ERK signaling, rescuing NSC proliferation. We show that NO from inflammatory origin leads to a decreased function of the EGF receptor, which compromised proliferation of NSC. We also demonstrated that NO-mediated nitration of the EGF receptor caused a decrease in its phosphorylation, thus preventing regular proliferation signaling through the ERK/MAPK pathway.Foundation for Science and Technology, (FCT, Portugal); COMPETE; FEDER [PEst-C/SAU/LA0001/2013-2014, PEst-OE/EQB/LA0023/2013-2014, PTDC/SAU-NEU/102612/2008, PTDC/NEU-OSD/0473/2012]; FCT, Portugal [SERH/BPD/78901/2011, SERH/BD/38127/2007, SFRH/BD/77903/2011, SFRH/BD/79308/2011]info:eu-repo/semantics/publishedVersio

BOBMEX: the Bay of Bengal monsoon experiment

The first observational experiment under the Indian Climate Research Programme, called the Bay of Bengal Monsoon Experiment (BOBMEX), was carried out during July-August 1999. BOBMEX was aimed at measurements of important variables of the atmosphere, ocean, and their interface to gain deeper insight into some of the processes that govern the variability of organized convection over the bay. Simultaneous time series observations were carried out in the northern and southern Bay of Bengal from ships and moored buoys. About 80 scientists from 15 different institutions in India collaborated during BOBMEX to make observations in most-hostile conditions of the raging monsoon. In this paper, the objectives and the design of BOBMEX are described and some initial results presented. During the BOBMEX field phase there were several active spells of convection over the bay, separated by weak spells. Observation with high-resolution radiosondes, launched for the first time over the northern bay, showed that the magnitudes of the convective available potential energy (CAPE) and the convective inhibition energy were comparable to those for the atmosphere over the west Pacific warm pool. CAPE decreased by 2-3 kJ kg-1 following convection, and recovered in a time period of 1-2 days. The surface wind speed was generally higher than 8 m s-1. The thermohaline structure as well as its time evolution during the BOBMEX field phase were found to be different in the northern bay than in the southern bay. Over both the regions, the SST decreased during rain events and increased in cloud-free conditions. Over the season as a whole, the upper-layer salinity decreased for the north bay and increased for the south bay. The variation in SST during 1999 was found to be of smaller amplitude than in 1998. Further analysis of the surface fluxes and currents is expected to give insight into the nature of coupling

Evidence for an evolutionary antagonism between Mrr and Type III modification systems

The Mrr protein of Escherichia coli is a laterally acquired Type IV restriction endonuclease with specificity for methylated DNA. While Mrr nuclease activity can be elicited by high-pressure stress in E. coli MG1655, its (over)expression per se does not confer any obvious toxicity. In this study, however, we discovered that Mrr of E. coli MG1655 causes distinct genotoxicity when expressed in Salmonella typhimurium LT2. Genetic screening enabled us to contribute this toxicity entirely to the presence of the endogenous Type III restriction modification system (StyLTI) of S. typhimurium LT2. The StyLTI system consists of the Mod DNA methyltransferase and the Res restriction endonuclease, and we revealed that expression of the LT2 mod gene was sufficient to trigger Mrr activity in E. coli MG1655. Moreover, we could demonstrate that horizontal acquisition of the MG1655 mrr locus can drive the loss of endogenous Mod functionality present in S. typhimurium LT2 and E. coli ED1a, and observed a strong anti-correlation between close homologues of MG1655 mrr and LT2 mod in the genome database. This apparent evolutionary antagonism is further discussed in the light of a possible role for Mrr as defense mechanism against the establishment of epigenetic regulation by foreign DNA methyltransferases