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Search Results: 1 - 10 of 185 matches for " NR.;Witter "
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Apis mellifera (Hymenoptera: Apidae) as a potential Brassica napus pollinator (cv. Hyola 432) (Brassicaceae), in Southern Brazil
Rosa, AS.;Blochtein, B.;Ferreira, NR.;Witter, S.;
Brazilian Journal of Biology , 2010, DOI: 10.1590/S1519-69842010000500024
Abstract: brassica napus linnaeus is considered a self-compatible crop; however, studies show that bee foraging elevates their seed production. considering bee food shortages during the winter season and that the canola is a winter crop, this study aimed to evaluate the foraging behaviour of apis mellifera linnaeus, 1758 regarding those flowers, and to verify if it presents adequate behaviour for successfully pollinating this crop in rio grande do sul state. the study was carried out in a canola field, in southern brazil. the anthesis stages were morphologically characterised and then related to stigma receptivity and pollen grain viability. similarly, the behaviour of a. mellifera individuals on flowers was followed, considering the number of flowers visited per plant, the amount of time spent on the flowers, touched structures, and collected resources. floral fidelity was inferred by analysing the pollen load of bees collected on flowers. the bees visited from 1-7 flowers/plant (x = 2.02; sd = 1.16), the time spent on the flowers varied between 1-43 seconds (x = 3.29; sd = 2.36) and, when seeking nectar and pollen, they invariably touched anthers and stigmas. the pollen load presented 100% of b. napus pollen. the bees' attendance to a small number of flowers/plants, their short permanence on flowers, their contact with anthers and stigma and the integral floral constancy allows their consideration as potential b. napus pollinators.
Schistosomiasis vaccine development: progress and prospects
Bergquist, NR;
Memórias do Instituto Oswaldo Cruz , 1998, DOI: 10.1590/S0074-02761998000700013
Abstract: the undisputed, worldwide success of chemotherapy notwithstanding, schistosomiasis continues to defy control efforts in as much rapid reinfection demands repeated treatment, sometimes as often as once a year. there is thus a need for a complementary tool with effect for the longer term, notably a vaccine. international efforts in this direction have been ongoing for several decades but, until the recombinant dna techniques were introduced, antigen production remained an unsurmountable bottleneck. although animal experiments have been highly productive and are still much needed, they probably do not reflect the human situation adequately and real progress can not be expected until more is known about human immune responses to schistosome infection. it is well-known that irradiated cercariae consistently produce high levels of protection in experimental animals but, for various reasons, this proof of principle cannot be directly exploited. research has instead been focussed on the identification and testing of specific schistosome antigens. this work has been quite successful and is already at the stage where clinical trials are called for. preliminary results from coordinated in vitro laboratory and field epidemiological studies regarding the protective potential of several antigens support the initiation of such trials. a series of meetings, organized earlier this year in cairo, egypt, reviewed recent progress, selecteded suitable vaccine candidates and made firm recommendations for future action including pledging support for large-scale production according to good manufacturing practice (gmp) and phase i trials. scientists at the american centers for disease control and prevention (cdc) have drawn up a detailed research plan. the major financial support will come from usaid, cairo, which has established a scientific advisory group of egyptian scientists and representatives from current and previous international donors such as who, niaid, the european union and t
Debunking three myths about Madagascar’s deforestation
NR Horning
Madagascar Conservation & Development , 2012,
Abstract: After more than three decades of describing, explaining, and tackling deforestation in Madagascar, the problem persists. Why do researchers, practitioners, politicians, and farmers remain perplexed about this problem? This essay offers that our collective thinking of the past three decades has inadvertently perpetuated three myths. The first is that farmers are central agents of deforestation. The second is that the Malagasy state has the capacity and willingness to address the problem. And the third is that Madagascar is unique, especially relative to the rest of Africa. This essay examines each of these established ‘truths’ in an effort to overcome deforestation and all the degradation – environmental, social, and economic – that accompanies it. It argues that the assumptions behind conservation policies and projects are perpetuated by a class of powerful domestic and foreign individuals whose interests are best served by not questioning their validity. It concludes that fighting deforestation from now on must entail a deliberate, collective effort to question these assumptions and a willingness to open up the thinking to farmers and fellow Africans.
The provision of recreation services for the aged in the Durban Metropolitan Area (DMA)
NR Ngcobo
Inkanyiso: Journal of Humanities and Social Sciences , 2010,
Abstract: This paper investigated the provision of recreation services for the aged in the Durban Metropolitan Area (DMA). The main argument in the research is that the aged like any other age groups need to be provided with recreation services. The objectives underpinning this investigation include the following: To reveal the adequacy of existing recreation services which are provided for the aged in the Durban Metropolitan Area. To determine the views that the aged population holds towards recreation participation by the aged. To establish the extent to which the aged in the Durban Metropolitan Area value their recreation participation. To establish the level of concessions granted to the aged by the recreation service providers in the Durban Metropolitan Area on utilising recreation facilities. A survey research method, comprising a self-completed questionnaire and a structured interview schedule, was used to gather data from the respondents who comprised 260 aged (main sample), 120 general members of the public and 10 recreation service providers in the DMA. This was further supplemented by the observation method. Having analysed the data, the chi-square test was used to test the validity and reliability of the hypotheses. The most salient findings indicate that the aged in the DMA are not adequately provided with recreation services, despite the fact that they attach certain positive values to recreation participation. The research further highlighted that the DMA needs to provide recreation programmes that the aged can afford. Non-prescriptive recommendations revolve inter alia around: conducting a needs analysis survey prior to the provision of recreation services for the aged. The location of recreation facilities to be used by the aged must be in an area that is easily accessible. Furthermore, the aged must be granted special concessions in the utilisation of recreation facilities.
NQO1*2 [NAD(P)H: quinone oxidoreductase 1] polymorphism and its influence on acute leukemia risk
NR. Dunna
Biology and Medicine , 2011,
Abstract: NAD (P) H: quinone oxidoreductase 1 (NQO1) is an enzyme that protects cells against mutagenicity from freeradicals and toxic oxygen metabolites. The gene coding for NQO1 has polymorphism at nucleotide position 609(C-T)of the human cDNA. Heterozygous individuals (C/T) have intermediate activity and homozygotes for the variant allele(T/T) are deficient in NQO1 activity. In previous studies, genotypes conferring lower NQO1 activity have beenassociated with an increased risk of acute leukemia. The present study includes 297 acute leukemia casescomprising of 151 acute lymphocytic leukemia (ALL), 146 acute myeloid leukemia (AML) and 220 control samples foranalysis of NQO1*2 polymorphism using PCR-RFLP method. The NQO1*2 polymorphism was significantlyassociated with acute leukemia development (χ2- 31.614; df-2, p - < 0.000) with respect to clinical variables. MeanWBC, Blast %, LDH levels were increased in both ALL and AML cases with TT genotype. 50% of AML cases failed toachieve complete remission towards therapy. There was significant reduction in mean DFS (Disease Free Survival) inboth ALL and AML cases with TT genotype (21.18m, 8.31m). Our results suggest that TT genotype might beconsidered as a risk genotype for development of acute leukemia and is associated with poor prognostic markers.
Ohtahara syndrome and IVF: A case report
Ashrafi NR
Acta Medica Iranica , 2000,
Abstract: Ohtahara syndrome or ealy infantile epileptic encephalopathy is a rare cause of epileptic seizures during infancy and represents the earliest type of age related symptomatic generalized epilepsies. The main etiologic factor associated with ohtahara syndrome is cerebran dysgenesis. This case was the product of in vitro fertilization (IVF) after 18 years of infertility . Neuroimaging findings consisted of diffuse white matter abnormalities, cortical atrophy and hemimegalencephaly. There is a previous report of this syndrome from Canada that was conceived throught IVF. A relation between IVF and the occurrence of Ohtahara synforme needs further observations.
Schistosomiasis vaccine development: progress and prospects
Bergquist NR
Memórias do Instituto Oswaldo Cruz , 1998,
Abstract: The undisputed, worldwide success of chemotherapy notwithstanding, schistosomiasis continues to defy control efforts in as much rapid reinfection demands repeated treatment, sometimes as often as once a year. There is thus a need for a complementary tool with effect for the longer term, notably a vaccine. International efforts in this direction have been ongoing for several decades but, until the recombinant DNA techniques were introduced, antigen production remained an unsurmountable bottleneck. Although animal experiments have been highly productive and are still much needed, they probably do not reflect the human situation adequately and real progress can not be expected until more is known about human immune responses to schistosome infection. It is well-known that irradiated cercariae consistently produce high levels of protection in experimental animals but, for various reasons, this proof of principle cannot be directly exploited. Research has instead been focussed on the identification and testing of specific schistosome antigens. This work has been quite successful and is already at the stage where clinical trials are called for. Preliminary results from coordinated in vitro laboratory and field epidemiological studies regarding the protective potential of several antigens support the initiation of such trials. A series of meetings, organized earlier this year in Cairo, Egypt, reviewed recent progress, selecteded suitable vaccine candidates and made firm recommendations for future action including pledging support for large-scale production according to good manufacturing practice (GMP) and Phase I trials. Scientists at the American Centers for Disease Control and Prevention (CDC) have drawn up a detailed research plan. The major financial support will come from USAID, Cairo, which has established a scientific advisory group of Egyptian scientists and representatives from current and previous international donors such as WHO, NIAID, the European Union and the Edna McConnell Clark Foundation.
Increasing long-term response to selection
NR Wray, ME Goddard
Genetics Selection Evolution , 1994, DOI: 10.1186/1297-9686-26-5-431
Abstract:
Representación social de las Técnicas de Reproducción Asistida
Romero Márquez,NR;
Revista de la Facultad de Medicina , 2002,
Abstract: this article constitutes part of a wider work over the social representation of the techniques of atended reproduction, where it states as problem the social representation of the reason to undergo the technique of fertilization in vitro, if it is necessary, in deloberate sample of 50 venezuelan professionals, of both sexes, concurrent to "suma" bookstore located in caracas, during january-april 1990. it was an exploratory-descriptive-interpretative research in which a structured interview was used applying a form of 39 question. only two question are analyzed. the methodology was fundamentally content?s analysis. answers were contained in four levels: a) right to have children, b) selection of son?s sex, c) to have descendants, d) elder?s protection. there are answers similar to those obtained by sadner that stand out values, beliefs, attitudes and fixed social stereotypes. we consider that scarce information exist on the technique and the motivation of a couple should be studied from the psico-social-cultural point of view before subjecting it to this procedure,as well as to inform through the media and legal and psychological and bioethics aspects involved.
Enhanced lipase production by mutation induced Aspergillus japonicus
SK Karanam, NR Medicherla
African Journal of Biotechnology , 2008,
Abstract: The purpose of the present investigation is to enhance production of the biomedically important enzyme, lipase, by subjecting the indigenous lipase producing fungal strain Aspergillus japonicus MTCC 1975 to strain improvement and random mutagenesis (UV irradiation, HNO2 and N-methyl-N’- nitro-N-nitroso guanidine). The isolation of mutants and the lipolytic activity of selected mutants were described. The best UV selectant (AUV3) showed 127% higher lipase activity than the parent strain. The lipase yield of the best HNO2 mutant (AHN3) was 139% higher than UV mutant (AUV3) and 177% higher than the parent strain. Also, the lipase yield of the best NTG mutant (ANT4) was 156% higher lipase activity than the HNO2 mutant (AHN3) and 217% higher than the UV mutant (AUV3) and 276% higher lipase activity than the parent strain. The results indicated that UV, HNO2 and NTG treatment were effective physical and chemical mutagenic agents for strain improvement of Aspergillus japonicus for enhanced lipase productivity.
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