The Effects of Established Trees on Woody Regeneration during Secondary Succession in Tropical Dry Forests

Understanding the mechanisms controlling secondary succession in tropical dry forests is important for the conservation and restoration of this highly threatened biome. Canopy‐forming trees in tropical forests strongly influence later stages of succession through their effect on woody plant regeneration. In dry forests, this may be complex given the seasonal interplay of water and light limitations. We reviewed observational and experimental studies to assess (1) the relative importance of positive and negative effects of established trees on regeneration; (2) the mechanisms underlying these effects; and (3) to test the 'stress gradient hypothesis' in successional tropical dry forests. The effects of established trees on seed dispersal, seed survival, and seed germination—either through direct changes to moisture and temperature regimes or mediated by seed dispersers and predators—are mainly positive. The balance between positive and negative effects on seedling establishment is more complex and depends on the season and leaf phenology of both trees and seedlings. Seedling survival is generally enhanced by established trees mitigating dry conditions. Established trees have counteracting effects on water and light availability that influence seedling growth. The probability of a positive effect of established trees on seedling survival decreases with increased rainfall, which supports the stress gradient hypothesis. Priorities for future research are experiments to test for facilitation and competition and their underlying mechanisms, long‐term studies evaluating how these effects change with ontogeny, and studies focusing on the species‐specificity of interactions

Participatory forest management in Burkina Faso: Members’ perception of performance

This study examines variations in the performance of participatory forest management programs among four forest management groups (FMGs) in southern Burkina Faso, and assesses the factors that influence their members’ perceptions of performance through a household survey of 216 members. Variations in performance scores among the FMGs were analyzed through multivariate analysis of variance while multinomial regression analysis was used to identify factors that influence their perception of the performance. The results reveal significant differences in performance scores among FMGs. Members of some FMGs perceived that the participatory forest management program enabled them to get benefits from the sale of fuelwood while performance scores in the forest conservation and decision-making processes is generally poor. The score for economic performance of FMGs in turn was related to better access to roads and markets. Group size tended to enhance economic performance via its strong influence on annual fuelwood harvest, while the resource base appeared to be inconsequential. Members of the forest management groups perceived that large group size and group heterogeneity, particularly in terms of ethnicity, as well as knowledge and awareness of problems related to the forest environment have no influence on the performance of their respective groups. For rural communities to have a favorable disposition toward sustainable forest management, differences in member understanding of collective actions and their impact before and during the implementation of participatory forest management programs should be considered

Factors in the suboptimum performance of rural water supply systems in the Ethiopian highlands

Access to safe drinking water services in the Ethiopian Highlands is one of lowest worldwide due to failure of water supply services shortly after construction. Over hundred water supply systems were surveyed to find the underlying causes of failure and poor performance throughout the Amhara Regional State. The results show generally that systems with decision-making power at the community level during design and construction remained working longer than when the decisions were made by a central authority. In addition, the sustainability was better for water systems that were farther away from alternative water resources and contributed more cash and labour. The results of this study of the importance of decision-making at the local level in contrast to the central authority is directly applicable to the introduction of rain water management systems as shown by earlier efforts of installing rain water harvesting systems in the Ethiopian highlands

The relationship between lifestyle and anthropometric factors with the sleep characteristics among university students in Iran: the MEPHASOUS study

Background: Healthy sleep habits have an important role in normal cognitive function, emotional performance, and well-being. The aims of this study were to describe the characteristics of sleep among university students in Iran. In addition, we assessed the relationship between lifestyle and anthropometric factors with the sleep characteristics. Methods: This population-based cross-sectional study was conducted using the data of �Mental and Physical Health Assessment of University Students in Iran� survey 2012�2013. This survey was conducted on newly admitted students in 74 public universities in 28 provinces. The participants were younger adults. Univariate and multivariate logistic regression models were utilized to recognize associated factors with sleep pattern and range. Result: Of total 78,848 students who completed the survey, 54.64 (n = 43,079) were females. The average age of the students was 21.53 ± 4.08 and 21.54 ± 3.99 among males and females, respectively. More than 90 (n = 70,923), were non-smokers. Out of the total respondents, 40.56 (n = 31,756) had irregular sleep pattern. Male students were less likely to have irregular sleep pattern than female students. Conclusion: Our findings indicated that irregular sleep pattern is associated with overweight and obesity. So, these results underscore the need to educate students on importance of healthy sleep pattern and duration on health conditions. © 2020, Springer Nature Switzerland AG

Outcome of preterm twins compared to preterm singleton neonates, a multicenter prospective observational study in Ethiopia

Background: In recent decades there has been a major increase in multiple birth rates, and the rate of twining vary from 6-9 per thousand life births to 20 per thousand live births across differ-ent areas of the world. Many studies have demonstrated higher neonatal and perinatal mortality and morbidity rates in twin deliveries compared to singleton births. This study was aimed to com-pare the outcomes of preterm twins and preterm singletons.Methods: A prospective, observational multicenter study was conducted from July 2016 to May 2018 in five tertiary hospitals in Ethiopia. All preterm, liveborn infants born at or transferred at less than 7 days of life to one of the study hospitals with an estimated gestational age below 37 weeks were included.Results: A total of 3,703 preterm neonates admitted to participating neonatal intensive care units were included in the study, of which 1171(31.6%) were twins. After adjusting for birth weight and gestational age, the mortality rate for preterm singletons of 31.0% was higher than the mortality rate for preterm twins of 24.8%, which was statistically significant (p-value = 0.001), OR of 1.37 (95% CI: 1.15 to 1.64). The study also identified an inverse relationship between birth weight and gestational age, and mortality. Male singletons were more likely to die than male twins (440 (32.4%) vs. 141 (23.4%); AOR 1.56 (95% CI: 1.22, 1.99); p=0.001)Conclusion: Our study showed that the mortality of a singleton preterm infant was significantly higher than the mortality of a preterm twin infan

A Prospective Study of Causes of Illness and Death in Preterm Infants in Ethiopia: The SIP Study Protocol

Background With nearly 15 million annual preterm births globally, preterm birth is the most common cause of neonatal death. Forty to 60 % of neonatal deaths are directly or indirectly associated with preterm mortality. As countries aim to meet the Sustainable Development Goals to reduce neonatal mortality, significant reductions in preterm mortality are needed. This study aims to identify the common causes of preterm illness and their contribution to preterm mortality in low-resource settings. This article will describe the methods used to undertake the study. Methods This is a prospective, multi-centre, descriptive clinical study. Socio-demographic, obstetric, and maternal factors, and clinical and laboratory findings will be documented. The major causes of preterm mortality will be identified using clinical, laboratory, imaging, and autopsy methods and use the national Ethiopian guidelines on management of preterm infants including required investigations to reach final diagnoses. The study will document the clinical and management protocols followed in these settings. The approach consists of clinical examinations and monitoring, laboratory investigations, and determination of primary and contributory causes of mortality through both clinical means and by post-mortem examinations. An independent panel of experts will validate the primary and contributory causes of mortality. To obtain the estimated sample size of 5000 preterm births, the study will be undertaken in five hospitals in three regions of Ethiopia, which are geographically distributed across the country. All preterm infants who are either born or transferred to these hospitals will be eligible for the study. Three methods (last menstrual period, physical examination using the New Ballard Score, and ultrasound) will be used to determine gestational age. All clinical procedures will be conducted per hospital protocol and informed consent will be taken from parents or caretakers prior to their participation in the study as well as for autopsy if the infant dies. Discussion This study will determine the major causes of death and illness among hospitalized preterm infants in a low-resource setting. The result will inform policy makers and implementers of areas that can be prioritized in order to contribute to a significant reduction in neonatal mortality

Chemotactic and Inflammatory Responses in the Liver and Brain Are Associated with Pathogenesis of Rift Valley Fever Virus Infection in the Mouse

Rift Valley fever virus (RVFV) is a major human and animal pathogen associated with severe disease including hemorrhagic fever or encephalitis. RVFV is endemic to parts of Africa and the Arabian Peninsula, but there is significant concern regarding its introduction into non-endemic regions and the potentially devastating effect to livestock populations with concurrent infections of humans. To date, there is little detailed data directly comparing the host response to infection with wild-type or vaccine strains of RVFV and correlation with viral pathogenesis. Here we characterized clinical and systemic immune responses to infection with wild-type strain ZH501 or IND vaccine strain MP-12 in the C57BL/6 mouse. Animals infected with live-attenuated MP-12 survived productive viral infection with little evidence of clinical disease and minimal cytokine response in evaluated tissues. In contrast, ZH501 infection was lethal, caused depletion of lymphocytes and platelets and elicited a strong, systemic cytokine response which correlated with high virus titers and significant tissue pathology. Lymphopenia and platelet depletion were indicators of disease onset with indications of lymphocyte recovery correlating with increases in G-CSF production. RVFV is hepatotropic and in these studies significant clinical and histological data supported these findings; however, significant evidence of a pro-inflammatory response in the liver was not apparent. Rather, viral infection resulted in a chemokine response indicating infiltration of immunoreactive cells, such as neutrophils, which was supported by histological data. In brains of ZH501 infected mice, a significant chemokine and pro-inflammatory cytokine response was evident, but with little pathology indicating meningoencephalitis. These data suggest that RVFV pathogenesis in mice is associated with a loss of liver function due to liver necrosis and hepatitis yet the long-term course of disease for those that might survive the initial hepatitis is neurologic in nature which is supported by observations of human disease and the BALB/c mouse model