Spatial patterns and processes in a regenerating mangrove forest

The global effort to rehabilitate and restore destroyed mangrove forests is unable to keep up with the high mangrove deforestation rates which exceed the average pace of global deforestation by three to five times. Our knowledge of the underlying processes of mangrove forest regeneration is too limited in order to find suitable techniques for the restoration of degraded mangrove areas. The general objective of my dissertation was to improve mangrove restoration by understanding regeneration processes and local plant-plant interaction in a regenerating Avicennia germinans forest. The study was conducted in a high-shore mangrove forest area on the Ajuruteua peninsula, State of Para, Northern Brazil. The dwarf forest consisting of shrub-like trees is recovering from a stand-replacing event caused by a road construction in 1974 which interrupted the tidal inundation of the study area. Consequently, infrequent inundation and high porewater salinity limit tree growth and canopy closure. All trees and seedlings were stem-mapped in six 20 m x 20 m plots which were located along a tree density gradient. Moreover, height, crown extent, basal stem diameter of trees were measured. The area of herbaceous ground vegetation and wood debris were mapped as well. The mapped spatial distribution of trees, seedlings and covariates was studied using point pattern analysis and point process models, such as Gibbs and Thomas point process, in order to infer underlying ecological processes, such as seed dispersal, seedling establishment, tree recruitment and tree interaction. In the first study (chapter 2), I analyzed the influence of abiotic and biotic factors on the seedling establishment and tree recruitment of A. germinans during the recolonization of severely degraded mangrove sites using point process modeling. Most seedlings established adjacent to adult trees especially under their crown cover. Moreover, seedling density was higher within patches of the herbaceous salt-marsh plants Blutaparon portulacoides and Sesuvium portulacastrum than in uncovered areas. The higher density of recruited A. germinans trees in herb patches indicated that ground vegetation did not negatively influence tree development of A. germinans. In addition, tree recruitment occurred in clusters. Coarse wood debris had no apparent effect on either life stage. These results confirm that salt-marsh vegetation acts as the starting point for mangrove recolonization and indicate that the positive interaction among trees accelerates forest regeneration. In the second study (chapter 3), I analyzed how intraspecific interaction among A. germinans trees determines their growth and size under harsh environmental conditions. Interaction among a higher number of neighboring trees was positively related to the development of a focal tree. However, tree height, internode length and basal stem diameter were only positively associated in low-density forest stands (1.2 trees m-2) and not in forest stands of higher tree density (2.7 trees m-2). These results indicated a shift from facilitation, i.e. a positive effect of tree interaction, towards a balance between facilitation and competition. In the third study (chapter 4), I used point process modeling and the individual-based model mesoFON to disentangle the impact of regeneration and interaction processes on the spatial distribution of seedlings and trees. In this infrequently inundated area, propagules of A. germinans are only dispersed at a maximum distance of 3 m from their parent tree. Furthermore, there is no evidence that the following seedling establishment is influenced by trees. I was able to differentiate positive and negative tree interactions simulated by the mangrove model mesoFON regardless of dispersal processes based on static tree size information using the mark-correlation function. The results of this dissertation suggest that mangrove forest regeneration in degraded areas is a result of facilitative and not competitive interactions among mangrove trees, seedling and herbaceous vegetation. This has important implications for the restoration of degraded mangrove forest. Degraded mangrove areas are usually restored by planting a high number of evenly spaced seedlings. However, high costs constrain this approach to small areas. Assisting natural regeneration could be a less costly alternative. Herbaceous vegetation plays a crucial role in forest recolonization by entrapping propagules and possibly ameliorating harsh environmental conditions. So far only competition among mangrove trees has been considered during restoration. However, facilitative tree interactions could be utilized by planting seedling clusters in order to assist natural regeneration instead of planting seedlings evenly-spaced over large areas. This dissertation also showed that point pattern analysis and point process modeling can enable forest ecologists to describe the spatial distribution of trees as well as to infer underlying ecological processes

Nature of English and Tiv Metatheses

Metathesis, the transposition of letters and syllables, is a minor phonological process that is found in both English and Tiv languages. This phonological process has not received much attention it deserves because most scholars considered it as a figure of misspelling which is not worthy of researching. This paper investigates the nature of English and Tiv metatheses. The objectives of this paper are to classify English and Tiv metatheses, discuss the formation of metatheses in English and Tiv and state the functions of metatheses in English and Tiv languages. This paper used comparative linguistic theory which compares the nature of English and Tiv metatheses. The researcher used participant observation tool for elicitation of data for this study. Secondary materials such as journal articles, textbooks, dictionaries and encyclopaedias and Internet sources were used. This study links phonology, historical linguistics, onomastics and language pathology (speech disorder). The study has established that metathesis has phonological, orthographic, metrical and onomastic relevance. This paper provides an in-depth material for teaching and learning of English and Tiv languages. It has been recommended that lecturers in the National Institute for Nigerian Languages, Departments of Linguistics and Nigerian Languages should write books and critical works on Nigerian or African languages

Prevalence and Associated Factors of Hypertension Among Civil Servants Working in Arba Minch Town, South Ethiopia

Despite Hypertension is a global public health challenge and a leading modifiable risk factor for cardiovascular disease and death attention was not given in developing countries. Therefore measuring the prevalence and identifying predictors of Hypertension is very important. Institution based cross sectional study design was employed from March–April, 2016 by taking 319 randomly selected civil servants working in in Arba Minch town. Data was collected using structured questionnaire and standardized instruments for physical examination by 5 trained nurses. SPSS version 20 was used for data analysis. Bi-variable and Multivariate logistic regression was employed for analysis of risk factors. The mean SBP and DBP of study participants were 120.87 + 14.15 mmHg and 80.28 + 8.8 mmHg, respectively. The prevalence of hypertension was found to be 27.8% (95% CI = 22.9-32.7%). Civil servants of age 50 years and above [AOR = 13.3], age 40-49 years [AOR = 5], age 30-39 years [AOR = 3.5], abdominal obesity [AOR=12.2], general obesity [AOR = 4.2], stress status [AOR = 12.3], current alcohol drink [AOR = 3.3], ex-drinker [AOR = 8.9] and family history of hypertension [AOR = 5.6] were found to be significantly associated with hypertension. The prevalence indicates that it is hidden epidemic in this population; therefore for screening and risk reduction program are needed

Does it fit okay? Problems with condom use as a function of self-reported poor fit

This is an open access article - Copyright © 2010 by the BMJ Publishing Group Ltd. All rights reservedOBJECTIVE: To identify associations between men's self-reports of ill-fitting condoms and selected condom use problems, using an event-specific analysis. METHODS: A convenience sample of men was recruited via advertisements in newspapers (two urban and one small town) and a blog on the website of a condom sales company. Men completed a questionnaire posted on the website of The Kinsey Institute for Research in Sex, Gender, and Reproduction. Inclusion criteria were: at least 18 years old, used condoms for penile–vaginal intercourse in the past 3 months and the ability to read English. RESULTS: In controlled, event-specific, analyses of 436 men, those reporting ill-fitting condoms (44.7%) were significantly more likely to report breakage (adjusted odds ratio (AOR 2.6), slippage (AOR 2.7), difficulty reaching orgasm, both for their female partners (AOR 1.9) and for themselves (AOR 2.3). In addition, they were more likely to report irritation of the penis (AOR 5.0) and reduced sexual pleasure, both for their female partner (AOR 1.6) and for themselves (AOR 2.4). Furthermore, they were more likely to report that condoms interfered with erection (AOR 2.0), caused erection loss (AOR 2.3), or became dry during sex (AOR 1.9). Finally, they were more likely to report removing condoms before penile–vaginal sex ended (AOR 2.0). CONCLUSIONS: Men and their female sex partners may benefit from public health efforts designed to promote the improved fit of condoms.Support for this project was provided, in part, by the Rural Center for AIDS/STD Prevention, a joint project of Indiana University, University of Colorado, and the University of Kentucky and by The Kinsey Institute for Research in Sex, Gender, and Reproduction, Indiana University

Intestinal helminth infections and dietary diversity score predict nutritional status of urban schoolchildren from southern Ethiopia

BACKGROUND: Undernutrition is a major public health problem in developing countries like Ethiopia where schoolchildren are among the vulnerable groups. However, limited attention has been given for the nutritional status of schoolchildren including the lack of available evidence on the magnitude and modifiable risk factors in different parts of the country. Thus, we aimed at determining the magnitude and predictors of undernutrition among schoolchildren in Arba Minch town, southern Ethiopia. METHODS: A school-based cross-sectional study was conducted in March and April, 2014 involving 532 schoolchildren aged 7 to 14 years. A two-stage probability sampling procedure was applied to select study schools and subjects. Anthropometry measurements were taken using standardized techniques and calibrated equipment. Intestinal parasite infections were determined from stool samples using direct saline method and formal ether concentration technique; whereas data on demographic and relevant risk factors were gathered through structured interview of caretakers. Bivariate and multivariable logistic regressions were used to identify predictors of stunting and wasting in the study population. RESULTS: The prevalence of stunting and wasting were 26.0% (95% CI: 22.3, 30.1%) and 11.7% (95% CI: 9.1, 14.9%), respectively. In multivariable model, poor household wealth [AOR (95% CI) = 3.2 (1.2, 8.5)], living in large family [AOR (95% CI) = 2.3 (1.0, 5.1)], lack of maternal formal education [AOR (95% CI) = 4.1 (1.8, 9.4)], low Dietary Diversity Score [AOR (95% CI) = 2.3 (1.2, 4.7)], A. lumbricoides [AOR (95% CI) = 5.0 (2.7, 9.4)], hookworm [AOR (95% CI) = 8.0 (4.0, 15.8)] and T. trichuria [AOR (95% CI) = 6.3 (2.8, 14.1)] infections were associated with stunting. Wasting status was independently associated with not living with both parents [AOR (95% CI) = 2.0 (1.0, 4.1)], poor household wealth [AOR (95% CI) = 8.9 (2.0, 39.2)], and recent illnesses [AOR (95% CI) = 6.3 (3.1, 12.6)]. CONCLUSIONS: Both acute and chronic malnutrition are prevalent among schoolchildren in the study area where intestinal parasite infections, poor dietary quality and common illnesses are important modifiable risk factors. A comprehensive school-based health and nutrition intervention involving parents may help to alleviate the problem including regular deworming and promotion of personal hygiene and balanced diet