Oxidation kinetics and inverse isotope effect of marine nitrite-oxidizing isolates

Nitrification, the step-wise oxidation of ammonium to nitrite and nitrate, is important in the marine environment because it produces nitrate, the most abundant marine dissolved inorganic nitrogen (DIN) component and N-source for phytoplankton and microbes. This study focused on the second step of nitrification, which is carried out by a distinct group of organisms, nitrite-oxidizing bacteria (NOB). The growth of NOB is characterized by nitrite oxidation kinetics, which we investigated for 4 pure cultures of marine NOB (Nitrospina watsonii 347, Nitrospira sp. Ecomares 2.1, Nitrococcus mobilis 231, and Nitrobacter sp. 311). We further compared the kinetics to those of non-marine species because substrate concentrations in marine environments are comparatively low, which likely influences kinetics and highlights the importance of this study. We also determined the isotope effect during nitrite oxidation of a pure culture of Nitrospina (Nitrospina watsonii 347) belonging to one of the most abundant marine NOB genera, and for a Nitrospira strain (Nitrospira sp. Ecomares 2.1). The enzyme kinetics of nitrite oxidation, described by Michaelis-Menten kinetics, of 4 marine genera are rather narrow and fall in the low end of half-saturation constant (Km) values reported so far, which span over 3 orders of magnitude between 9 and >1000 µM NO2-. Nitrospina has the lowest Km (19 µM NO2-), followed by Nitrobacter (28 µM NO2-), Nitrospira (54 µM NO2-), and Nitrococcus (120 µM NO2-). The isotope effects during nitrite oxidation by Nitrospina watsonii 347 and Nitrospira sp. Ecomares 2.1 were 9.7 ± 0.8 and 10.2 ± 0.9‰, respectively. This confirms the inverse isotope effect of NOB described in other studies; however, it is at the lower end of reported isotope effects. We speculate that differences in isotope effects reflect distinct nitrite oxidoreductase (NXR) enzyme orientations

HIV testing and tolerance to gender based violence : a cross-sectional study in Zambia

This paper explores the effect of social relations and gender-based conflicts on the uptake of HIV testing in the South and Central provinces of Zambia. We conducted a community-based cross-sectional study of 1716 randomly selected individuals. Associations were examined using mixed-effect multivariable logistic regression. A total of 264 men (64%) and 268 women (56%) had never tested for HIV. The strongest determinants for not being tested were disruptive couple relationships (OR = 2.48 95% CI = 1.00-6.19); tolerance to gender-based violence (OR = 2.10 95% CI = 1.05-4.32) and fear of social rejection (OR = 1.48 95% CI = 1.23-1.80). In the Zambian context, unequal power relationships within the couple and the community seem to play a pivotal role in the decision to test which until now have been largely underestimated. Policies, programs and interventions to rapidly increase HIV testing need to urgently address gender-power inequity in relationships and prevent gender-based violence to reduce the negative impact on the lives of couples and families

Access to HIV/AIDS care: a systematic review of socio-cultural determinants in low and high income countries

BACKGROUND: The role of socio-cultural factors in influencing access to HIV/AIDS treatment, care and support is increasingly recognized by researchers, international donors and policy makers. Although many of them have been identified through qualitative studies, the evidence gathered by quantitative studies has not been systematically analysed. To fill this knowledge gap, we did a systematic review of quantitative studies comparing surveys done in high and low income countries to assess the extent to which socio-cultural determinants of access, identified through qualitative studies, have been addressed in epidemiological survey studies. METHODS: Ten electronic databases were searched (Cinahl, EMBASE, ISI Web of Science, IBSS, JSTOR, MedLine, Psyinfo, Psyindex and Cochrane). Two independent reviewers selected eligible publications based on the inclusion/exclusion criteria. Meta-analysis was used to synthesize data comparing studies between low and high income countries. RESULTS: Thirty-four studies were included in the final review, 21 (62%) done in high income countries and 13 (38%) in low income countries. In low income settings, epidemiological research on access to HIV/AIDS services focused on socio-economic and health system factors while in high income countries the focus was on medical and psychosocial factors. These differences depict the perceived different barriers in the two regions. Common factors between the two regions were also found to affect HIV testing, including stigma, high risk sexual behaviours such as multiple sexual partners and not using condoms, and alcohol abuse. On the other hand, having experienced previous illness or other health conditions and good family communication was associated with adherence to ART uptake. Due to insufficient consistent data, a meta-analysis was only possible on adherence to treatment. CONCLUSIONS: This review offers evidence of the current challenges for interdisciplinary work in epidemiology and public health. Quantitative studies did not systematically address in their surveys important factors identified in qualitative studies as playing a critical role on the access to HIV/AIDS services. The evidences suggest that the problem lies in the exclusion of the qualitative information during the questionnaire design. With the changing face of the epidemic, we need a new and improved research strategy that integrates the results of qualitative studies into quantitative survey

Bledzew (kościół parafialny) - dzwon (datowanie - 1511 r.)

Wreszcie dzwon o identycznym gmerku znajdował się również w Gorzycy w pow. Międzyrzecz. Instrumenty zidentyfikowane w powiecie międzyrzeckim mają identyczną inskrypcję, tj. cytat wg Ewangelii św. Jana 19, 19. Nie można jednak tego faktu uogólniać, gdyż na innych instrumentach występują także inne teksty.

The impact of varying warning color on e-cigarette advertisements: Results from an online experiment among young adults.

INTRODUCTION: Advertisement warnings are often overlooked, which reduces the opportunity for risk communication. METHODS: We used Prolific to survey 1131 young adults (18–35) who currently used e-cigarettes or tobacco products. We randomized participants to one of four warning conditions: black text on white background (BW), white on black (WB), black on yellow (BY), and yellow on black (YB). We examined associations between condition and attention, recall, ad appeal, perceived message effectiveness (PME), and intentions to use e-cigarettes using chi-square and analysis of variance (ANOVA) where appropriate. We conducted logistic regressions by condition for attention and recall controlling for demographics and tobacco use. RESULTS: The warning was selected as the most attention-capturing area of the advertisement more often by those exposed to yellow warnings than white (59.9% vs. 46.8%), even after controlling for demographics and tobacco use (p < .05). Recall was greater among those exposed to yellow warnings than white (44.2% vs. 37.3%), which held in controlled models. There were no significant differences between yellow and white warnings for ad appeals, PME, or intentions to use. In subanalyses, WB warnings generated higher PME (10.1 vs. 9.5) and lower intentions to use e-cigarettes (3.0 vs. 3.3) than black on white (BW) (each p < .05). CONCLUSIONS: Yellow warning color increases attention and recall of the warning, but this increase in attention did not translate to differences in downstream effects. Among currently mandated warning variations, the white text on black background warning appears more effective than the BW. Future research should examine whether differences translate to behavior change. IMPLICATIONS: We tested color variations of the FDA-mandated nicotine text warning on e-cigarette advertisements. Yellow variations (yellow text on black background and BY) better-captured attention and increased warning recall compared to the mandated black and white warnings. Among the FDA-mandated BW and WB warnings, the WB variation appears more effective, generating higher perceived message effectiveness and lower intentions to use e-cigarettes. Given the difficulty in implementing pictorial warnings in the United States, color might represent an alternative to improve warning effectiveness. Findings may also be applicable to those designing tobacco-related health communications