Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 13 de 13
Filter
1.
Environ Pollut ; 243(Pt B): 1952-1965, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30318134

ABSTRACT

Organic fertilizers, such as digestates and manure, are increasingly applied in agricultural systems because of the benefits they provide in terms of plant nutrients and soil quality. However, there are few investigations of N2O emissions following digestate application to agricultural soils using process-based models. In this study, we modified the UK-DNDC model to include digestate applications to soils by adding digestate properties to the model and considering the effect of organic fertilizer pH. Using the modified model, N2O emissions were simulated from two organic fertilizers (digested food waste and livestock slurry) applied to three farms in the United Kingdom: one growing winter wheat at Wensum (WE) and two grasslands at Pwllpeiran (PW) and North Wyke (NW). The annual cumulative gross (i.e. not excluding control emission) N2O emissions were calculated using MATLAB trapezoidal numerical integration. The relative errors of the modeled annual cumulative emissions to the measured emissions ranged from -5.4% to 48%. Two-factor models, including linear, exponential and hyperbola responses, correlating total N loading and soil clay content to calculations of N2O emissions and N2O emission factors (EFs) were developed for calculations of emission fluxes and EFs. The squares of the correlation coefficients of the measured and two-factor linear modeled emissions were 0.998 and 0.999 for digestate and slurry, respectively, and the corresponding squares of correlation coefficients of the EFs were 0.998 and 0.938. The two-factor linear model also predicted that the EFs increased linearly with decreasing clay content and the maximum EFs for digestate and slurry were 0.95 and 0.76% of total N applied, respectively. This demonstrates that the modified UK_DNDC is a good tool to simulate N2O emission from digestate and slurry and to calculate UK EFs using TIER 3 methodology..


Subject(s)
Agriculture/methods , Fertilizers/analysis , Manure/analysis , Nitrous Oxide/analysis , Soil/chemistry , Animals , Livestock , Nitrous Oxide/chemistry , Poaceae/growth & development , Triticum/growth & development , United Kingdom
2.
Sci Total Environ ; 637-638: 1566-1577, 2018 Oct 01.
Article in English | MEDLINE | ID: mdl-29801250

ABSTRACT

Organic fertilizers, such as manure and compost, are promising additions for synthetic fertilizers in order to increase soil fertility and crop yields. However, the organic fertilizers applied to soils may increase nitrous oxide (N2O, a greenhouse gas) emissions due to their lower C/N ratios, and therefore potentially contribute to global warming. Very few studies have used process-based models to assess the environmental advantages and drawbacks of compost soil amendments compared to other field treatments. In this study, the UK-DNDC model was modified for simulation of nitrous oxide (N2O) fluxes emitted from the soils treated with green compost and farmyard manure at three UK farms (WE, PW and NW): one winter wheat and two grasslands. The results show that the annual overall N2O emissions were 1.45 kg N ha-1 y-1 for WE treated with farmyard manure, 0.71 for WE with green compost, 1.09910 for PW treated with farmyard manure, 0.94 for PW treated with green compost, 1.19 for NW treated with farmyard manure, and 1.18 for NW treated with green compost. A two dimensional linear model was developed to correlate nitrogen loading and soil pH for calculations of emissions and emission factors (EFs). The linear model could fit the emissions obtained from the UK-DNDC model well. The squares of correlation coefficients of the emissions between two models are 0.993 and 0.985 for farmyard manure and green compost, respectively. Analysis of correlation coefficients between N2O emissions and air temperature, precipitation as well as the time period between fertilizer application and sample measurement (PFS) for the three sites treated with farmyard manure and compost indicated that N2O emissions were mainly related to PFS. The modified DNDC model provides an approach to estimating N2O emissions from compost amended soils.

3.
Environ Pollut ; 228: 504-516, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28578866

ABSTRACT

The anaerobic digestion of food waste for energy recovery produces a nutrient-rich digestate which is a valuable source of crop available nitrogen (N). As with any 'new' material being recycled to agricultural land it is important to develop best management practices that maximise crop available N supply, whilst minimising emissions to the environment. In this study, ammonia (NH3) and nitrous oxide (N2O) emissions to air and nitrate (NO3-) leaching losses to water following digestate, compost and livestock manure applications to agricultural land were measured at 3 sites in England and Wales. Ammonia emissions were greater from applications of food-based digestate (c.40% of total N applied) than from livestock slurry (c.30% of total N applied) due to its higher ammonium-N content (mean 5.6 kg/t compared with 1-2 kg/t for slurry) and elevated pH (mean 8.3 compared with 7.7 for slurry). Whilst bandspreading was effective at reducing NH3 emissions from slurry compared with surface broadcasting it was not found to be an effective mitigation option for food-based digestate in this study. The majority of the NH3 losses occurred within 6 h of spreading highlighting the importance of rapid soil incorporation as a method for reducing NH3 emissions. Nitrous oxide losses from food-based digestates were low, with emission factors all less than the IPCC default value of 1% (mean 0.45 ± 0.15%). Overwinter NO3- leaching losses from food-based digestate were similar to those from pig slurry, but much greater than from pig farmyard manure or compost. Both gaseous N losses and NO3- leaching from green and green/food composts were low, indicating that, in these terms, compost can be considered as an 'environmentally benign' material. These findings have been used in the development of best practice guidelines which provide a framework for the responsible use of digestates and composts in agriculture.


Subject(s)
Agriculture/methods , Nitrogen/analysis , Ammonia/analysis , Animals , England , Fertilizers , Food , Gases/analysis , Livestock , Manure , Nitrates , Nitrous Oxide/analysis , Soil/chemistry , Swine , Wales
4.
Psychol Trauma ; 9(3): 309-316, 2017 05.
Article in English | MEDLINE | ID: mdl-28459272

ABSTRACT

OBJECTIVE: Sexual assaults against women are a global health crisis, with alarmingly high rates in South Africa. However, we know very little about the circumstances and the aftermath of these experiences. Further, there is limited information about how factors specific to the rape (e.g., fighting back) versus those that are specific to the individual-and potentially modifiable-influence mental health outcomes. This study examined how situational characteristics of rape as well as individual and situational factors confer risk for symptoms of depression, posttraumatic stress disorder (PTSD), and dysfunctional sexual behavior at 12-month follow-up. METHOD: Two hundred nine (N = 209) South African women were recruited from rural rape clinics in the Limpopo Province (LP) and North West Province (NWP) of South Africa. Interviews were conducted at baseline (within 6 months of the rape incident) and at 6 and 12 months by trained staff at the clinics in English or the women's native languages. Women were interviewed after services were provided in a private room. RESULTS: One hundred thirty-two (n = 132) women were lost to follow-up at 12 months, resulting in 77 women with interview data for all time points. Undermining by the survivor's social support system and an increased belief in myths about rape were associated with increased dysfunctional sexual practices and symptoms of depression. CONCLUSIONS: These findings demonstrate the need for interventions that address the most pervasive effects of rape over time. These behaviors can increase risks for revictimization and reduce psychological well-being in the aftermath of rape. (PsycINFO Database Record


Subject(s)
Crime Victims/psychology , Depression/diagnosis , Psychological Trauma/diagnosis , Rape/psychology , Stress Disorders, Post-Traumatic/diagnosis , Survivors/psychology , Adolescent , Adult , Culture , Depression/psychology , Female , Humans , Longitudinal Studies , Psychological Trauma/psychology , Rural Population , Social Support , South Africa , Stress Disorders, Post-Traumatic/psychology , Young Adult
6.
Infect Dis Obstet Gynecol ; 2015: 563727, 2015.
Article in English | MEDLINE | ID: mdl-26617456

ABSTRACT

BACKGROUND: Previous studies examining protease inhibitor use in pregnancy and the rate of preterm and small-for-gestational-age infants have yielded conflicting results. METHODS: This was a retrospective study of HIV-infected women who delivered singleton infants at our institution between 1984 and 2014. Women with protease inhibitor use were compared to women on regimens without a protease inhibitor as well as those who received no antepartum antiretroviral therapy. Infants were considered preterm if less than 37 completed weeks of gestation and small-for-gestational-age if less than 10th percentile. RESULTS: During the study period 1,004 pregnancies met inclusion criteria. Of those, 597 received a protease inhibitor as part of their regimen, 230 ART without a protease inhibitor, and 177 no ART. There was no difference in the rate of preterm birth between groups who received ART with or without a protease inhibitor, 14% versus 13%. There was no difference in the rate of small-for-gestational-age infants between the three groups. Use of a protease inhibitor was associated with a greater fall in viral load during pregnancy, p < 0.001. CONCLUSION: In this population with access to prenatal care and ART, treatment with protease inhibitors was associated with a greater fall in viral load, but not an increase in small or preterm infants.


Subject(s)
HIV Infections/drug therapy , HIV Protease Inhibitors/therapeutic use , Infectious Disease Transmission, Vertical/prevention & control , Pregnancy Complications, Infectious/drug therapy , Protease Inhibitors/therapeutic use , Adolescent , Adult , Birth Weight/drug effects , Female , HIV Infections/epidemiology , HIV Protease Inhibitors/pharmacology , Humans , Infant, Premature , Pregnancy , Pregnancy Complications, Infectious/epidemiology , Protease Inhibitors/pharmacology , Retrospective Studies , Viral Load/drug effects , Young Adult
7.
Respir Med Case Rep ; 14: 27-9, 2015.
Article in English | MEDLINE | ID: mdl-26029572

ABSTRACT

In this case report, we describe the utilisation of two recently developed technologies for the successful management of a persistent air leak (PAL) in a critically ill patient in whom cardiothoracic surgical intervention was not possible. We report the case of a young leukaemic woman with a PAL complicating Invasive Pulmonary Aspergillosis (IPA), who was effectively managed using an Endobronchial Valve, supplemented by objective, digital air leak data provided by a Thopaz(®) device (Medela, Switzerland).

8.
Int J Womens Health ; 2: 393-9, 2010 Nov 10.
Article in English | MEDLINE | ID: mdl-21151687

ABSTRACT

Polycystic ovary syndrome (PCOS) affects 2%-26% of women of reproductive age and is often accompanied by obesity. Modest weight loss reduces health risks and ameliorates effects of the syndrome. Weight loss interventions are mainly of short duration and have limited success. A systematic review of the literature was carried out to assess the efficacy of long-term (12 months), nonsurgical weight loss interventions for women with PCOS. Fifteen databases were searched, resulting in eight papers that met the search criteria. Comparison of results and meta-analysis was difficult due to heterogeneity of studies. Behavioral components of interventions were poorly described, and compliance was difficult to ascertain. The results suggested that the inclusion of a lifestyle component improves outcomes, but protocols must be clearly described to maintain study validity and to identify successful behavioral strategies.

9.
Am J Gastroenterol ; 100(10): 2315-23, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16181386

ABSTRACT

Computed tomographic colonography (CTC) is a relatively noninvasive technique for large bowel imaging that has the ability to detect colorectal neoplasia. Already well established as a reliable diagnostic tool in symptomatic patients who are unable to undergo complete colonoscopy, it is now being considered as a viable method for population screening. Advances in technique over the past 10 yr make this an attractive alternative, including reduced bowel preparation and stool tagging, three-dimensional (3D) image reconstruction, computer-aided detection software, and low-radiation dose protocols. CTC may be favored by patients compared to other available screening tests due to the ease of performance and comfort. Although published studies vary in relation to the sensitivity of this test for the detection of polyps, in the best hands a sensitivity of greater than 90% for detection of polyps at least 10 mm in diameter may be obtained. Although not yet endorsed for widespread use by major gastroenterological societies, CTC shows promise as a screening tool.


Subject(s)
Colonography, Computed Tomographic , Colorectal Neoplasms/diagnostic imaging , Colonography, Computed Tomographic/economics , Colonography, Computed Tomographic/methods , Colorectal Neoplasms/pathology , Cost-Benefit Analysis , Humans , Patient Satisfaction , Patient Selection , Reproducibility of Results , Sensitivity and Specificity
10.
J Med Screen ; 12(2): 89-95, 2005.
Article in English | MEDLINE | ID: mdl-15949120

ABSTRACT

OBJECTIVES: To study an individual's experience of either flexible sigmoidoscopy (FS) or colonoscopy in a colorectal cancer prevention programme. METHODS: Consecutive individuals in a Bowel Cancer Prevention Programme, who had either an unsedated FS or a colonoscopy with sedation, participated in a prospective cross-sectional questionnaire-based study. RESULTS: A total of 447 responses were obtained for 256 colonoscopies and 191 FSs (200 men [45%] and 247 women [55%]). The overall experience of colonoscopy was more comfortable than FS (75% versus 18%; P<0.001). Embarrassment was low for both procedures (8%). There was no pain associated with colonoscopy and most individuals had a pain score of less than 3 (11-point scale) for FS: 72% of men, 55% of women (P<0.001). Most individuals did not have a gender preference for the endoscopist. For colonoscopy, the worst part of the procedure was the preparation (78%) and for FS the preparation and the procedure ranked equally worst (30%). CONCLUSIONS: We have shown that colonoscopy with sedation is a very comfortable procedure. FS is more uncomfortable than colonoscopy; however, for the majority it is a tolerable experience. Women found FS only slightly more painful than men. The worst part of either procedure was the preparation. Embarrassment with either procedure was minimal. Both procedures are well tolerated and suitable for colorectal cancer screening.


Subject(s)
Colonoscopy/methods , Colorectal Neoplasms/prevention & control , Sigmoidoscopy/methods , Colonoscopes , Colonoscopy/psychology , Colorectal Neoplasms/diagnosis , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Mass Screening , Pain Threshold , Patient Acceptance of Health Care , Patient Satisfaction , Sex Factors , Sigmoidoscopes , Sigmoidoscopy/psychology , Surveys and Questionnaires
11.
Bioresour Technol ; 96(2): 135-43, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15381209

ABSTRACT

This paper reports the first year results of field experiments to determine the survival times of pathogens in livestock manures during storage and following land application, using viable count methods. E. coli O157, Salmonella and Campylobacter survived in stored slurries and dirty water for up to three months, with Listeria surviving for up to three months. In contrast, all these pathogens survived for less than one month in solid manure heaps where temperatures greater than 55 degrees C were obtained. Following manure spreading to land, E. coli O157, Salmonella and Campylobacter generally survived in the soil for up to one month after application to both the sandy arable and clay loam grassland soils, whereas Listeria commonly survived for more than one month. These data are being used to develop guidelines on the management of manures to minimize the risks of pathogen transfer from animal manures to the human food chain.


Subject(s)
Fertilizers/microbiology , Manure/microbiology , Agriculture/methods , Animals , Animals, Domestic , Campylobacter/physiology , Cattle , Escherichia coli O157/physiology , Listeria/physiology , Salmonella/physiology , Soil Microbiology , Time Factors
12.
Gastrointest Endosc ; 60(3): 400-7, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15332031

ABSTRACT

BACKGROUND: This study compared the experiences of women who underwent endoscopic screening for colorectal cancer vs. their experiences with breast and cervical cancer screening by mammography and Pap smear, respectively. METHODS: Women who had either flexible sigmoidoscopy or colonoscopy as a screening procedure for colorectal cancer were asked to return a questionnaire by mail. In the questionnaire, they were asked about the procedure they had just undergone and to compare it with recent mammograms and Pap smears. Flexible sigmoidoscopy was performed without sedating the patient; colonoscopy was performed with the patient under deep sedation (midazolam, fentanyl, and propofol administered by an anesthesiologist). RESULTS: Responses were obtained from 258 women (88%). Of these, 152 had colonoscopy and 106 had flexible sigmoidoscopy. A total of 72% of respondents found colonoscopy to be a comfortable test. Only 26% found flexible sigmoidoscopy uncomfortable, which was similar to mammography and Pap smear, at 22%. In terms of the test considered to be the most embarrassing, the highest response rate (38%) was for the Pap smear. Most women had no preference as to the gender of the endoscopist, but 46% preferred a woman doctor for a Pap smear (p < 0.001). Preparation was regarded as the worst part of the colonoscopy procedure; for flexible sigmoidoscopy, the procedure itself and the preparation were equivalent. CONCLUSIONS: Women found flexible sigmoidoscopy or colonoscopy comfortable and less embarrassing than a Pap smear or a mammography. There was no preference with respect to the gender of the physician who performed the colorectal screening procedures, unlike the Pap smear. Most respondents would have the procedure again and would recommend it to others.


Subject(s)
Colonoscopy , Colorectal Neoplasms/diagnosis , Mammography , Mass Screening , Papanicolaou Test , Patient Compliance , Sigmoidoscopy , Vaginal Smears , Adult , Aged , Colonoscopy/psychology , Colonoscopy/statistics & numerical data , Colorectal Neoplasms/psychology , Female , Health Knowledge, Attitudes, Practice , Humans , Mammography/psychology , Mammography/statistics & numerical data , Mass Screening/psychology , Mass Screening/statistics & numerical data , Middle Aged , Patient Compliance/psychology , Patient Compliance/statistics & numerical data , Patient Satisfaction/statistics & numerical data , Sigmoidoscopy/psychology , Sigmoidoscopy/statistics & numerical data , Surveys and Questionnaires , Vaginal Smears/psychology , Vaginal Smears/statistics & numerical data , Victoria
13.
FEMS Microbiol Ecol ; 43(1): 13-9, 2003 Feb 01.
Article in English | MEDLINE | ID: mdl-19719692

ABSTRACT

Abstract Around half a million tonnes of biosolids (sewage sludge dry solids) are applied to agricultural land in the United Kingdom each year, and this may increase to 732 000 t by 2005/6. The heavy metals contained in biosolids may permanently degrade the microbial decomposer communities of agricultural soils. We used amplified ribosomal DNA restriction analysis of the extractable bacterial fraction to compare the diversity of a zinc-contaminated soil (400 mg kg(-1) Zn; pH 5.7 and 1.36% C(org)) with that of a control soil (57 mg kg(-1) Zn; pH 6.2 and 1.40% C(org)) from a long-term sewage sludge experiment established in 1982 at ADAS Gleadthorpe. Comparison of the restriction fragment length polymorphisms of 236 clones from each soil suggested that the stress caused by zinc toxicity had lowered bacterial diversity. There were 120 operational taxonomic units (OTUs) in the control soil, but only 90 in the treated soil, a decrease of 25%. While the control soil had 82 single-occurrence OTUs the contaminated soil had only 52. The fall in diversity was accompanied by a decrease in evenness. The most abundant OTUs in the contaminated soil (which tended to be common to both soils) accounted for a higher proportion of clones than in the control. The most dominant OTU, in both soils, belonged to the Rubrobacter radiotolerans group of the high G+C Gram-positive bacteria. The data was also used to develop efficient sampling strategies.

SELECTION OF CITATIONS
SEARCH DETAIL
...