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11.
A laboratory practical experiment in Biotechnology involving the investigation of alpha-amylase production by solid state fermentation of Gibberella fujikuroi is described. 相似文献
12.
Background
The human menstrual cycle is known to exhibit a significant amount of unexplained variability. This variation is typically dismissed as random fluctuations in an otherwise periodic and predictable system. Given the many delayed nonlinear feedbacks in the multiple levels of the reproductive endocrine system, however, the menstrual cycle can properly be construed as the output of a nonlinear dynamical system, and such a system has the possibility of being in a chaotic trajectory. We hypothesize that this is in fact the case and that it accounts for the observed variability. 相似文献13.
Gordon Mansergh Beryl A. Koblin David J. McKirnan Sharon M. Hudson Stephen A. Flores Ryan E. Wiegand David W. Purcell Grant N. Colfax for the Project MIX Study Team 《PLoS medicine》2010,7(8)
Background
Substance use during sex is associated with sexual risk behavior among men who have sex with men (MSM), and MSM continue to be the group at highest risk for incident HIV in the United States. The objective of this study is to test the efficacy of a group-based, cognitive-behavioral intervention to reduce risk behavior of substance-using MSM, compared to a randomized attention-control group and a nonrandomized standard HIV-testing group.Methods and Findings
Participants (n = 1,686) were enrolled in Chicago, Los Angeles, New York City, and San Francisco and randomized to a cognitive-behavioral intervention or attention-control comparison. The nonrandomized group received standard HIV counseling and testing. Intervention group participants received six 2-h group sessions focused on reducing substance use and sexual risk behavior. Attention-control group participants received six 2-h group sessions of videos and discussion of MSM community issues unrelated to substance use, sexual risk, and HIV/AIDS. All three groups received HIV counseling and testing at baseline. The sample reported high-risk behavior during the past 3 mo prior to their baseline visit: 67% reported unprotected anal sex, and 77% reported substance use during their most recent anal sex encounter with a nonprimary partner. The three groups significantly (p<0.05) reduced risk behavior (e.g., unprotected anal sex reduced by 32% at 12-mo follow-up), but were not different (p>0.05) from each other at 3-, 6-, and 12-mo follow-up. Outcomes for the 2-arm comparisons were not significantly different at 12-mo follow-up (e.g., unprotected anal sex, odds ratio = 1.14, confidence interval = 0.86–1.51), nor at earlier time points. Similar results were found for each outcome variable in both 2- and 3-arm comparisons.Conclusions
These results for reducing sexual risk behavior of substance-using MSM are consistent with results of intervention trials for other populations, which collectively suggest critical challenges for the field of HIV behavioral interventions. Several mechanisms may contribute to statistically indistinguishable reductions in risk outcomes by trial group. More explicit debate is needed in the behavioral intervention field about appropriate scientific designs and methods. As HIV prevention increasingly competes for behavior-change attention alongside other “chronic” diseases and mental health issues, new approaches may better resonate with at-risk groups.Trial Registration
ClinicalTrials.gov Please see later in the article for the Editors'' Summary NCT00153361相似文献14.
Facente SN Pilcher CD Hartogensis WE Klausner JD Philip SS Louie B Christopoulos KA Dowling T Colfax GN 《PloS one》2011,6(7):e21813
Background
Federal guidelines now recommend supplemental HIV RNA testing for persons at high risk for acute HIV infection. However, many rapid HIV testing sites do not include HIV RNA or p24 antigen testing due to concerns about cost, the need for results follow-up, and the impact of expanded venipuncture on clinic flow. We developed criteria to identify patients in a municipal STD clinic in San Francisco who are asymptomatic but may still be likely to have acute infection.Methods
Data were from patients tested with serial HIV antibody and HIV RNA tests to identify acute HIV infection. BED-CEIA results were used to classify non-acute cases as recent or longstanding. Demographics and self-reported risk behaviors were collected at time of testing. Multivariate models were developed and preliminarily evaluated using predictors associated with recent infection in bivariate analyses as a proxy for acute HIV infection. Multivariate models demonstrating ≥70% sensitivity for recent infection while testing ≤60% of patients in this development dataset were then validated by determining their performance in identifying acute infections.Results
From 2004–2007, 137 of 12,622 testers had recent and 36 had acute infections. A model limiting acute HIV screening to MSM plus any one of a series of other predictors resulted in a sensitivity of 83.3% and only 47.6% of patients requiring testing. A single-factor model testing only patients reporting any receptive anal intercourse resulted in 88.9% sensitivity with only 55.2% of patients requiring testing.Conclusions
In similar high risk HIV testing sites, acute screening using “supplemental” HIV p24 antigen or RNA tests can be rationally targeted to testers who report particular HIV risk behaviors. By improving the efficiency of acute HIV testing, such criteria could facilitate expanded acute case identification. 相似文献15.
Sequence analysis of the ribosomal DNA internal transcribed spacer 2 from populations of Anopheles nuneztovari (Diptera: Culicidae) 总被引:3,自引:0,他引:3
Sequence variation of the ribosomal DNA internal transcribed spacer 2
(ITS2) was examined for populations of the malaria vector Anopheles
nuneztovari collected in Colombia, Venezuela, Bolivia, Suriname, and
Brazil. Mosquitoes from Colombia and Venezuela had identical ITS2 sequences
and were distinguished from sequences in other populations by three
insertion/deletion events (indels) and by one transversion. The length of
the ITS2 was 363-369 bp, and it had a G+C content of 55.3%- 55.7%.
Variation in the length of the ITS2 between and within populations was due
to indels in simple repeats. ITS2 consensus sequences were similar or
identical for samples from the following three groups: (1) Colombia,
Bolivia, and Venezuela; (2) Suriname and northern Brazil; and (3) eastern
and central Brazil. The presence of two different consensus sequences from
a single location near Manaus, Brazil, suggests that populations from
eastern Brazil and those from Suriname converge in this region of the
Amazon Basin. These data show that putative cryptic species of An.
nuneztovari are distinguished by very minor differences in DNA sequence of
the ITS2 region.
相似文献
16.
JU Nnadi IN Dimelu SI Nwani JC Madu CI Atama GN Attamah 《African Journal of Aquatic Science》2018,43(1):27-34
The current study investigated the effects of termite insecticide, Termex® (imidacloprid 35.50% SC), on biometric variations and oxidative stress biomarkers in Clarias gariepinus. Fish were exposed to 4.00 and 6.00 µg l–1 sublethal Termex® concentrations in 2017. The gill and liver tissues were sampled on days 7, 14, 21 and 28 and the results indicated that hepatosomatic index (HSI) decreased significantly when compared with the control on days 14, 21 and 28. The condition factor (CF) and viscera-somatic index (VSI) also decreased during the study period. The decrease was greater at 6.00 µg l–1 Termex® concentration on days 21 and 28 for CF and days 14 to 28 for VSI, respectively. The lipid peroxidation (LPO) in both tissues was highest in the 6.00 µg l?1 Termex® and increased with the duration. There was significant decrease (p < 0.05) in superoxide dismutase and glutathione peroxidase values, but significant increase in catalase activity in both tissues. The values of glutathione reductase in both tissues were comparable to the control, except on days 21 and 28 in the liver. There was negative correlation between the LPO in tissues and the HSI, CF and VSI values. The use of Termex® in the environment should be monitored to safeguard the health of aquatic organisms. 相似文献
17.
Alzheimer''s disease (AD) is the most common form of dementia. It is the sixth leading cause of death in old age people. Despite
recent advances in the field of drug design, the medical treatment for the disease is purely symptomatic and hardly effective. Thus
there is a need to understand the molecular mechanism behind the disease in order to improve the drug aspects of the disease. We
provided two contributions in the field of proteomics in drug design. First, we have constructed a protein-protein interaction
network for Alzheimer''s disease reviewed proteins with 1412 interactions predicted among 969 proteins. Second, the disease
proteins were given confidence scores to prioritize and then analyzed for their homology nature with respect to paralogs and
homologs. The homology persisted with the mouse giving a basis for drug design phase. The method will create a new drug design
technique in the field of bioinformatics by linking drug design process with protein-protein interactions via signal pathways. This
method can be improvised for other diseases in future. 相似文献
18.
19.
Like other flagellates, Gonyaulax polyedra exhibits diurnal vertical migration and pattern formation. Shape and size of the aggregations depend on container type, light intensity, and cell density. In Petri dishes, cells form oval "swarms"; within these, cells move downward in the highly dense center and rise up at the periphery. We have investigated the daily rhythm of this swarming activity in Petri dishes illuminated from the side, using time-lapse video recordings. At night, a "lawn" of cells forms at the bottom of the dish toward the light source (independent of light intensity). Before dawn, cells rise toward the surface and aggregate in swarms. The daily vertical migration occurs independent of light direction and intensity. The diurnal swarms, however, form every day at the same location within the dish, at a distance from the light that depends on light intensity, indicating a self-selection of light intensity. In constant light and temperature and with negligible vertical nutrient differences, all aspects of the rhythm continue to oscillate for up to 3 weeks, when the rhythm of the population becomes desynchronized. Under cycles of bright white-dim red light (WR), cell entrain to WR 10:10 but free run in WR 8:8 and shorter cycles, showing relative coordination (von Holst, 1939) to the driving light cycle. They also entrain to the 24-hr multiple of WR 6:6. Under nonentrained conditions, swarming activity is still influenced by light changes, and in spite of the apparent free run, the phasing of the averaged activity varies systematically with different T-cycle frequencies. 相似文献
20.
Bas E Dutilh Cristiane C Thompson Ana CP Vicente Michel A Marin Clarence Lee Genivaldo GZ Silva Robert Schmieder Bruno GN Andrade Luciane Chimetto Daniel Cuevas Daniel R Garza Iruka N Okeke Aaron Oladipo Aboderin Jessica Spangler Tristen Ross Elizabeth A Dinsdale Fabiano L Thompson Timothy T Harkins Robert A Edwards 《BMC genomics》2014,15(1)