330 research outputs found
Reduction of gray mold development in table grapes by preharvest sprays with ethanol and calcium chloride.
Preharvest applications of a 16% ethanol (EtOH) solution, containing 1 % of calcium chloride (CaCl2), reduced gray mold development in ‘Chasselas’ table grapes picked at a late harvest date, the losses due to rotten clusters dropped from 15% in controls to 5% in grapes treated with EtOH+CaCl2. Then over a 6-week cold storage, the losses due to gray mold rots were reduced by 50% when storing EtOH+CaCl2 treated clusters, compared to untreated controls. Preliminary experiments had shown that a 2% EtOH solution was already inducing significant drop of gray mold growth. A range of concentrations up to 50% ethanol had been tested in preliminary trials without observing damages to the vines and clusters. The treatments did not induce significant changes to the fruit quality assessed by sensory analyses on healthy berries
Ethanol vapours limit Botrytis development over the postharvest life of table grapes
The application of ethanol vapours has been optimised over two seasons in order to prevent rot development, caused by Botrytis cinerea, and stem browning in 'Chasselas' table grapes. At a dose rate of 2 ml per kg of grapes, ethanol vapour was as effective as sulphur dioxide pads. Consumer panels detected no significant difference in sensory perception between controls and treated grapes. The ethanol vapour treatment could be easily implemented by the table grape industry since the technology is similar to sulphur dioxide treatment
Potential for Ethanol Vapours to Limit Table Grape Berry Shatter and to Limit Ethylene Evolution from Clusters
We have shown previously that ethanol vapours (given by 2 ml per kg of grapes) can prevent Botrytis development and stem browning, two of the major problems in postharvest quality of table grapes. In the present paper, we will give emphasis to preliminary results about (i) the role of ethanol vapours in the inhibition of berry shatter and (ii) the control of ethylene evolution from grapes bunches by ethanol vapours and the link to the control of Botryti
Superficial Scald versus Ethanol Vapours: A Dose Response
Early picked "Granny Smith" apples (Malus domestica Borkh.) were stored under air or CA (controlled atmosphere at 2 kPa O2 and <1 kPa CO2) at 1°C. During the first week of storage, fruit was subjected to ethanol vapours in doses
from 0 to 8 g/kg of fruit. Ethanol at 4 g/kg protected fruit against superficial scald in
CA storage for at least 5.5 months, plus two weeks in cold air storage, plus a week at
ambient temperature. Ethanol at 6 g/kg protected fruit in cold air storage for 3
months, plus a week at ambient temperature. Effects of ethanol vapours and CA on
headspace ethylene levels are discussed. Ethanol vapours did not cause significant
off-flavours in "Granny Smith" apples (consumer panel, hedonic scale), or purpling
of the skin of Red Delicious apples (visual assessment)
Ethanol Vapours to Complement or Replace Sulfur Dioxide Fumigation of Table Grapes
Recent studies have shown that dipping table grapes in ethanol solutions at harvest improved storage of the fruit. We report here the first results obtained by treating "Chasselas" table grapes (Vitis vinifera) with ethanol vapours over the storage period. We tested the effect of ethanol at 0, 4 and 8 g/kg fruit during cold storage for 2, 4 and 6 weeks. We measured berry shatter, stem browning, Botrytis rot incidence and sensory appreciation by tasting panels. Ethanol vapours reduced Botrytis rot incidence and berry shatter, but hastened stem browning. Sensory analyses did not detect any differences between treatments
Concurrent partnerships in Cape Town, South Africa : race and sex differences in prevalence and duration of overlap
Introduction: Concurrent partnerships (CPs) have been suggested as a risk factor for transmitting HIV, but their impact on the epidemic depends upon how prevalent they are in populations, the average number of CPs an individual has and the length of time they overlap. However, estimates of prevalence of CPs in Southern Africa vary widely, and the duration of overlap in these relationships is poorly documented. We aim to characterize concurrency in a more accurate and complete manner, using data from three disadvantaged communities of Cape Town, South Africa.
Methods: We conducted a sexual behaviour survey (n = 878) from June 2011 to February 2012 in Cape Town, using Audio Computer-Assisted Self-Interviewing to collect sexual relationship histories on partners in the past year. Using the beginning and end dates for the partnerships, we calculated the point prevalence, the cumulative prevalence and the incidence rate of CPs, as well as the duration of overlap for relationships begun in the previous year. Linear and binomial regression models were used to quantify race (black vs. coloured) and sex differences in the duration of overlap and relative risk of having CPs in the past year.
Results: The overall point prevalence of CPs six months before the survey was 8.4%: 13.4% for black men, 1.9% for coloured men, 7.8% black women and 5.6% for coloured women. The median duration of overlap in CPs was 7.5 weeks. Women had less risk of CPs in the previous year than men (RR 0.43; 95% CI: 0.32-0.57) and black participants were more at risk than coloured participants (RR 1.86; 95% CI: 1.17-2.97).
Conclusions: Our results indicate that in this population the prevalence of CPs is relatively high and is characterized by overlaps of long duration, implying there may be opportunities for HIV to be transmitted to concurrent partners
Coital frequency and condom use in monogamous and concurrent sexual relationships in Cape Town, South Africa
Introduction: A decreased frequency of unprotected sex during episodes of concurrent relationships may dramatically reduce the role of concurrency in accelerating the spread of HIV. Such a decrease could be the result of coital dilution - the reduction in per-partner coital frequency from additional partners - and/or increased condom use during concurrency. To study the effect of concurrency on the frequency of unprotected sex, we examined sexual behaviour data from three communities with high HIV prevalence around Cape Town, South Africa.
Methods: We conducted a cross-sectional survey from June 2011 to February 2012 using audio computer-assisted self-interviewing to reconstruct one-year sexual histories, with a focus on coital frequency and condom use. Participants were randomly sampled from a previous TB and HIV prevalence survey. Mixed effects logistic and Poisson regression models were fitted to data from 527 sexually active adults reporting on 1210 relationship episodes to evaluate the effect of concurrency status on consistent condom use and coital frequency.
Results: The median of the per-partner weekly average coital frequency was 2 (IQR: 1 - 3), and consistent condom use was reported for 36% of the relationship episodes. Neither per-partner coital frequency nor consistent condom use changed significantly during episodes of concurrency (aIRR = 1.05; 95% confidence interval (CI): 0.99-1.24 and aOR = 1.01; 95% CI: 0.38-2.68, respectively). Being male, coloured, having a tertiary education, and having a relationship between 2 weeks and 9 months were associated with higher coital frequencies. Being coloured, and having a relationship lasting for more than 9 months, was associated with inconsistent condom use.
Conclusions: We found no evidence for coital dilution or for increased condom use during concurrent relationship episodes in three communities around Cape Town with high HIV prevalence. Given the low levels of self- reported consistent condom use, our findings suggest that if the frequency of unprotected sex with each of the sexual partners is sustained during concurrent relationships, HIV-positive individuals with concurrent partners may disproportionately contribute to onward HIV transmission
"After my husband's circumcision, I know that I am safe from diseases": Women's Attitudes and Risk Perceptions Towards Male Circumcision in Iringa, Tanzania.
While male circumcision reduces the risk of female-to-male HIV transmission and certain sexually transmitted infections (STIs), there is little evidence that circumcision provides women with direct protection against HIV. This study used qualitative methods to assess women's perceptions of male circumcision in Iringa, Tanzania. Women in this study had strong preferences for circumcised men because of the low risk perception of HIV with circumcised men, social norms favoring circumcised men, and perceived increased sexual desirability of circumcised men. The health benefits of male circumcision were generally overstated; many respondents falsely believed that women are also directly protected against HIV and that the risk of all STIs is greatly reduced or eliminated in circumcised men. Efforts to engage women about the risks and limitations of male circumcision, in addition to the benefits, should be expanded so that women can accurately assess their risk of HIV or STIs during sexual intercourse with circumcised men
Submarine record of volcanic island construction and collapse in the Lesser Antilles arc: First scientific drilling of submarine volcanic island landslides by IODP Expedition 340
IODP Expedition 340 successfully drilled a series of sites offshore Montserrat, Martinique and Dominica in the Lesser Antilles from March to April 2012. These are among the few drill sites gathered around volcanic islands, and the first scientific drilling of large and likely tsunamigenic volcanic island-arc landslide deposits. These cores provide evidence and tests of previous hypotheses for the composition and origin of those deposits. Sites U1394, U1399, and U1400 that penetrated landslide deposits recovered exclusively seafloor-sediment, comprising mainly turbidites and hemipelagic deposits, and lacked debris avalanche deposits. This supports the concepts that i/ volcanic debris avalanches tend to stop at the slope break, and ii/ widespread and voluminous failures of pre-existing low-gradient seafloor sediment can be triggered by initial emplacement of material from the volcano. Offshore Martinique (U1399 and 1400), the landslide deposits comprised blocks of parallel strata that were tilted or micro-faulted, sometimes separated by intervals of homogenized sediment (intense shearing), while Site U1394 offshore Montserrat penetrated a flat-lying block of intact strata. The most likely mechanism for generating these large-scale seafloor-sediment failures appears to be propagation of a decollement from proximal areas loaded and incised by a volcanic debris avalanche. These results have implications for the magnitude of tsunami generation. Under some conditions, volcanic island landslide deposits comprised of mainly seafloor sediment will tend to form smaller magnitude tsunamis than equivalent volumes of subaerial block-rich mass flows rapidly entering water. Expedition 340 also successfully drilled sites to access the undisturbed record of eruption fallout layers intercalated with marine sediment which provide an outstanding high-resolution dataset to analyze eruption and landslides cycles, improve understanding of magmatic evolution as well as offshore sedimentation processes. This article is protected by copyright. All rights reserved
Spatial distribution and cluster analysis of sexual risk behaviors reported by young men in Kisumu, Kenya
<p>Abstract</p> <p>Background</p> <p>The well-established connection between HIV risk behavior and place of residence points to the importance of geographic clustering in the potential transmission of HIV and other sexually transmitted infections (STI).</p> <p>Methods</p> <p>To investigate the geospatial distribution of prevalent sexually transmitted infections and sexual behaviors in a sample of 18-24 year-old sexually active men in urban and rural areas of Kisumu, Kenya, we mapped the residences of 649 men and conducted spatial cluster analysis. Spatial distribution of the study participants was assessed in terms of the demographic, behavioral, and sexual dysfunction variables, as well as laboratory diagnosed STIs. To test for the presence and location of clusters we used Kulldorff's spatial scan statistic as implemented in the Satscan program.</p> <p>Results</p> <p>The results of this study suggest that sexual risk behaviors and STIs are evenly distributed in our sample throughout the Kisumu district. No behavioral or STI clusters were detected, except for condom use. Neither urban nor rural residence significantly impacted risk behavior or STI prevalence.</p> <p>Conclusion</p> <p>We found no association between place of residence and sexual risk behaviors in our sample. While our results can not be generalized to other populations, the study shows that geospatial analysis can be an important tool for investigating study sample characteristics; for evaluating HIV/STI risk factors; and for development and implementation of targeted HIV and STI control programs in specifically defined populations and in areas where the underlying population dynamic is poorly understood.</p
- …
