Nitrogen mineralization dynamics of different valuable organic amendments commonly used in agriculture

Published online: 27 February 2016This is an open access article under the CC BY-NC-ND licenseSustainable agriculture requires the careful optimization of the use of organic amendments to improve soil fertility while minimizing any harmful environmental effects. To understand the events that occur in soil after the addition of different organic amendments, we evaluated the nitrogen (N) mineralization dynamics in soil after adding organic amendments, and evaluated changes in the microbial population. The four organic amendments were fresh dairy cattle manure, fresh white clover, vegetable, fruit, and yard waste compost, and poplar tree compost. The N mineralization potential of each organic amendment was determined by analyzing total mineral nitrogen during a 97-day laboratory incubation experiment. Soils amended with clover released 240 μg N g−1 soil during the 97-day incubation, more than twice as much as that released from soils amended with manure or composts (76–100 μg N g−1 soil). At the end of the incubation, the net N mineralization in clover-amended soils was 54%, more than five times higher than that in soils amended with composts or manure (4%–9%). Nitrogen was mineralized faster in clover-amended soil (1.056 μg N g−1 soil day−1) than in soil amended with composts (0.361–0.417 μg N g−1 soil day−1). The microbial biomass carbon content was higher in clover-amended soil than in the soils amended with manure or composts. We monitored changes in the microbial population in amended soils by a phospholipid fatty acid (PLFA) analysis. On day 97, there were higher concentrations of total PLFAs in soils with organic amendments (e.g., 14.41 nmol g−1 in clover-amended soil) than in control soil without amendments (9.84 nmol g−1). Bacteria (Gram-positive and Gram-negative), actinomycetes, and fungi were more abundant in clover-amended soils than soils amended with manure or composts. The N mineralization potential varied among the four organic amendments. Therefore, the timing of application and the type of organic amendment should be matched to the nutrient needs of the crop

De novo mutations in MED13, a component of the Mediator complex, are associated with a novel neurodevelopmental disorder

Genetics of disease, diagnosis and treatmen

Depression and its associated factors among patients with diabetes: A cross-sectional survey at Mnazi Mmoja Referral Hospital in Zanzibar, Tanzania.

BackgroundDepression is one of the mental illnesses that cause disability worldwide, and is a significant contributor to the global burden of diseases. Although depression is reported among patients with diabetes in high-income countries, it remains undetected or undiagnosed in low and middle-income countries. This article describes the prevalence of depression and its associated factors among patients with diabetes in Zanzibar, United Republic of Tanzania.Materials and methodsA cross-sectional study design was conducted at Mnazi Mmoja Referral Hospital (MMRH). A simple random sampling method was used to select the potential participants. Depressive symptoms were assessed using Patient Health Questionnaire-9(PHQ-9). Data were coded and analyzed using SPSS 23.0. A Chi-square test was performed to obtain the association between depression and socio-demographic, medical and psychological factors. A P-value of ResultsA total of 267 patients with diabetes responded to the questionnaire of which 142 (53.2%) were males. The mean age of participants was 50 years and a standard deviation of ±14. The overall prevalence of depression in this study was 73%. The specific type of depression among diabetic patients varied from severe (8%) to mild depression (30%). Respondents who had difficulties in adhering to the treatment regimen (AOR = 5.7: 95% CI, 2.11-15.18, p = 0.001), feeling angry or stressed (AOR = 4.4: 95% CI, 2.44-8.10, pConclusionThe majority of patients with diabetes have symptoms of depression. Adherence to the treatment regimen, diabetic retinopathy, feeling angry or stressed, impotence and diabetic foot ulcer were associated with depression. Thus, early screening of depression among patients with diabetes is crucial to enhance self-management and good health outcomes

Sexual Behaviours and Practices before and after Phase I/II HIV Vaccine Trial: A Qualitative Study among Volunteers in Dar es Salaam Tanzania

There is limited information about sexual behavior among volunteers who participated in phase I/II human immunodeficiency virus (HIV) vaccine trial. This article describes the sexual behavior, practices before, and after participation in phase I/II HIV vaccine trial in Dar es Salaam, Tanzania. We conducted a qualitative descriptive study involving volunteers who participated in the phase I/II vaccine trial between 2007 and 2010. Purposeful sampling was used to recruit potential informants. Twenty-four in-depth interviews were conducted. The audio-recorded interviews were transcribed verbatim and analyzed using a thematic content analysis approach. The findings revealed that before participation in the HIV vaccine trial, informants were engaging in unprotected multiple sexual relationships. After the completion of the HIV vaccine trial, informants reported strengthened marital relationships, increased understanding of safer sexual practices, and HIV testing. However, the informants reported challenges regarding vaccine-induced seropositivity that adversely affected their sexual and marital relationships. Some informants re-engaged in risky sexual practices because they perceived the experimental vaccine was protective. The informants suggested having continued interventions within the community to enhance safer sexual practices. Participation in phase I/II HIV vaccine trials may positively and negatively influence changes in volunteers’ sexual behaviors and practices. The trial interventions appear to improve compliance with safer sexual practices. However, the reported vaccine-induced seropositivity and the perception that experimental vaccines are protective need further appropriate interventions

Willingness to Participate in Hypothetical HIV Vaccine Trial and Associated Factors among People Who Inject Drugs in Dar es Salaam, Tanzania

This study is aimed at assessing the willingness to participate in the HIV vaccine trials and the associated factors among people who inject drugs (PWIDs) in Tanzania. Information about the willingness to participate and the associated factors was collected using interviewer-administered questionnaires at the medication treatment for opioid use disorder (MOUD) clinic in Dar es Salaam. Data analysis was performed using the IBM SPSS Statistic 20. The mean age of respondents was 36.7, and the standard deviation (SD) was ±7.2. The majority of respondents (68%) had primary education, and a high proportion of them were single (61.5%). More than one-third (37.9%) shared needles and syringes. Most (87.3%) had more than three sexual partners, and almost half (51.4%) did not use condoms during sexual intercourse with nonregular partners. About 63% had knowledge of HIV transmission while 27% had heard about HIV vaccine trials. Generally, 76% of the respondents expressed willingness to participate in future HIV vaccine trials regardless of prior knowledge of HIV vaccine trials. Willingness to participate in HIV vaccine trials was not associated with education level, people living with, knowledge about HIV transmission, awareness of HIV vaccine trials, sharing of syringe/needles, and number of sexual partners. Only older age (OR=1.6, 95%CI=1.01, 2.6) and condom use (OR=0.49, 95%CI=0.26, 0.97) showed an association with willingness. However, after performing logistic regression with factors at p value ≤ 0.2 to ascertain the other factors on the effects of age, condom use, education level, and sharing of needles/syringes, the results were not statistically significant. Although participants reported a high willingness to participate in hypothetical HIV vaccine trials, no definitive conclusion can be drawn about the associated factors. Further studies with intensive educational programs are needed to investigate the factors on willingness to participate in actual HIV vaccine trials among PWIDs

Experiences of family caregivers in caring for patients with heart failure admitted at Jakaya Kikwete Cardiac Institute, Dar es Salaam, Tanzania: A qualitative study.

BackgroundHeart failure (HF) continues to be a global health problem with its ramifications more pronounced in underdeveloped countries. Family members play a pivotal part in patient management which may influence the patient's overall quality of life. Prolonged delay in attendance to health care facilities among patients indicates ineffective support from family caregivers. In the Tanzanian context, there is limited information about the experiences of family caregivers in caring for patients with HF. This study explored family caregivers' experiences in caring for HF patients.MethodsA qualitative descriptive study design was conducted at Jakaya Kikwete Cardiac Institute in Dar es Salaam, Tanzania. A purposive sampling technique was used to select the potential participants. A sample size of 10 family caregivers of patients with HF was included in the study. Thematic analysis was used to derive the main theme and sub-themes.ResultsThree major themes were identified: demands for supportive care, new caring role and lifestyle, and professional support in caring for patients with HF. Caregivers needed social and financial support to facilitate the caring process. Learning to provide the required care at the right time was the new role acquired by caregivers while failing to participate in social events and caregiving in an unfavourable environment were reported as challenges in caregiving. However, compliance with instruction and effective interaction among the nurses and caregivers were considered to be positive professional support.ConclusionCaregivers need social and financial support to provide effective care to their patients. Caregiving is a learning process that needs continuous educational support to adapt to the new caring roles and challenges. Nurses should conduct regular assessments to explore caregivers' needs, challenges, and concerns and provide timely counselling that can facilitate coping

A Comparison of Functional Magnetic Resonance Imaging Findings in Children With and Without a History of Early Exposure to General Anesthesia

Background Functional magnetic resonance imaging (fMRI) has been used to evaluate the long-term consequences of early exposure to neurotoxic agents. fMRI shows that different patterns of brain activation occur in ethanol-exposed subjects performing a go/no-go response inhibition task. Pharmacologically, ethanol and general anesthetics have similar receptor-level activity in the brain. This study utilizes fMRI to examine brain activation patterns in children exposed to general anesthesia and surgery during early brain development. Methods After obtaining Nationwide Children\u27s Hospital IRB approval, a surgical database was utilized to identify children aged 10–17 years with a history of at least 1 h of exposure to general anesthetics and surgery when they were between 0 and 24 months of age. Age- and gender-matched children without anesthesia exposure were recruited as a control group. All subjects were scanned while being presented with a go/no-go response inhibition task. Reaction time and accuracy data were acquired, and the blood-oxygen-level-dependent (BOLD) fMRI signal was measured as a biomarker for regional neuronal activity. Results There were no differences in terms of performance accuracy and response time. The analysis did not reveal any significant activation differences in the primary region of interest (prefrontal cortex and caudate nucleus); however, activation differences were seen in other structures, including the cerebellum, cingulate gyrus, and paracentral lobule. Conclusions Early anesthetic exposure and surgery did not affect accuracy, response time, or activation patterns in the primary region of interest during performance of the task. Intergroup differences in activation patterns in other areas of the brain were observed, and the significance of these findings is unknown. fMRI appears to be a useful tool in evaluating the long-term effects of early exposure to general anesthesia

Socio-demographic characteristics of patients attending the diabetic Clinic at Mnazi Mmoja Referral Hospital.

Socio-demographic characteristics of patients attending the diabetic Clinic at Mnazi Mmoja Referral Hospital.</p