Evaluation of site quality of an upland hardwood forest at Scott County, Tennessee

Management of upland hardwood forests involves many problems and is still at an early stage of development. A better understanding of the inherent complexity of these forests will be required before better schemes of forest management can be planned. Site evaluation is a management problem of high priority. Large numbers of species forming many-aged stands which are frequently abnormally stocked characterize upland hardwood forests. Under such conditions neither growth nor site index methodology can be directly applied to assess forest productivity. This study was conducted to determine the feasibility of the site index methodology for evaluating site productivity of a tract of the Cumberland Forest Station of the University of Tennessee in Scott County. By stepwise multiple regression analysis it was found that: – Site index of chestnut oak can be estimated (r2 = 0. 50) using logarithm of langleys/basal area ratio, total basal area growth (10-year periodic growth) and slope position as independent variables. – Site index of white oak can be estimated (r2 = 0. 45) using azimuth, slope position, white oak basal area growth (10-year periodic growth) and total basal area growth (10-year periodic growth) of the study plot as independent variables. – Yellow poplar site index can be estimated (r2 = 0.35) using azimuth and effect of surrounding landmasses, arctangent exposure, as independent variables. – Total basal area growth (ten-year periodic growth) of the study plots can be estimated (r = 0. 58) using chestnut oak basal area growth (10-year periodic growth) and chestnut oak site index as independent variables. – Basal area growth of yellow poplar (10-year periodic growth) can be estimated (r2 = 0. 35) using altitude, exposure percent, and logarithm of langleys/basal area ratio as independent variables. The most useful variables for estimating site productivity were azimuth, slope position, logarithm of langley s/basal area ratio, basal area of the plot, and total basal area growth (10-year periodic growth)

Higher In vitro Proliferation Rate of Rhizopus oryzae in Blood of Diabetic Individuals in Chronic Glycaemic Control Compared with Non-diabetic Individuals

We thank all members of the Laboratory of Clinical Microbiology in the Hospital General Dr. Manuel Gea González, Instituto Nacional de Rehabilitacion and Hospital General de México. Also, thanks to the Wellcome Trust Strategic Award, corresponding author’s scholarship sponsor. Financial Support This study did not have pharmaceutical or grant support, and resources were obtained from institutional budgets.Peer reviewedPublisher PD

VLA Observations of H I in the Helix Nebula (NGC 7293)

We report the detection of 21-cm line emission from H I in the planetary nebula NGC 7293 (the Helix). The observations, made with the Very Large Array, show the presence of a ring of atomic hydrogen that is associated with the outer portion of the ionized nebula. This ring is most probably gas ejected in the AGB phase that has been subsequently photodissociated by radiation from the central star. The H I emission spreads over about 50 km/s in radial velocity. The mass in H I is approximately 0.07 solar masses, about three times larger than the mass in molecular hydrogen and comparable with the mass in ionized hydrogen.Comment: 19 pages, 9 figure

HIV Drug Resistance-Associated Mutations in Antiretroviral Naïve HIV-1-Infected Latin American Children

Our goal was to describe the presence of HIV drug resistance among HIV-1-infected, antiretroviral (ARV) naïve children and adolescents in Latin America and to examine resistance in these children in relation to drug exposure in the mother. Genotyping was performed on plasma samples obtained at baseline from HIV-1-infected participants in a prospective cohort study in Brazil, Argentina, and Mexico (NISDI Pediatric Study). Of 713 HIV-infected children enrolled, 69 were ARV naïve and eligible for the analysis. At enrollment, mean age was 7.3 years; 81.2% were infected with HIV perinatally. Drug resistance mutations (DRMs) were detected in 6 (8.7%; 95% confidence interval 3.1–18.2%) ARV-naïve subjects; none of the mothers of these 6 received ARVs during their pregnancies and none of the children received ARV prophylaxis. Reverse transcriptase mutations K70R and K70E were detected in 3 and 2 subjects, respectively; protease mutation I50 V was detected in 1 subject. Three of the 6 children with DRMs initiated ARV therapy during followup, with a good response in 2. The overall rate of primary drug resistance in this pediatric HIV-infected population was low, and no subjects had more than 1 DRM. Mutations associated with resistance to nucleoside reverse transcriptase inhibitors were the most prevalent