96,897 research outputs found

    Intermodal freight transport logistics : applications for improving port performance in Nigeria

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    Spatial patterns and processes in a regenerating mangrove forest

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    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

    Nasalisation as a Phonological Process in Tiv

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    Tiv phonology has major and minor phonological processes and nasalisation belongs to the former. This study explores the nature of the Tiv nasalisation process. It describes Tiv nasals; discusses syllabic nasal consonants; examines the nature of nasalised vowels and differentiates between oral and nasal sounds. This study used Generative Phonology model which was popularised by Chomsky and Halle’s (1968). The Sound Pattern of English. This model formulates theories that help in the analysis of Tiv nasals and points out that vowels that precede nasal consonants are nasalised. The author used participant-observation instrument for data collection. Both primary and documentary sources are used in this study. It has been observed that Tiv phonology has pre-nasalised consonants. It has been discovered that Tiv language has five nasal consonants: /m/, /n/, /?/, /?/ and /?/. It has also been noted that /m/, /n/, /?/ and /?/ appear at the word-initial, medial and final positions of Tiv words. It has also been known that nasals have phonological, morphological and syntactic functions. It has been recommended that learners should pronounce n in nd, ng, nj, nk, and nz as /?d/, /?g/, /??/, /?k/ and /?z/ and should note that /m/ and /?/ are not the same: /m/ is a bilabial nasal whereas /?/ is labio-dental sound. Researchers should carry out acoustic description of nasals and describe articulatory processes of producing nasals

    Nature of English and Tiv Metatheses

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    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

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    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

    Processes of Care Associated With Risk of Mortality and Recurrent Stroke Among Patients With Transient Ischemic Attack and Nonsevere Ischemic Stroke

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    Importance: Early evaluation and management of patients with transient ischemic attack (TIA) and nonsevere ischemic stroke improves outcomes. Objective: To identify processes of care associated with reduced risk of death or recurrent stroke among patients with TIA or nonsevere ischemic stroke. Design, Setting, and Participants: This cohort study included all patients with TIA or nonsevere ischemic stroke at Department of Veterans Affairs emergency department or inpatient settings from October 2010 to September 2011. Multivariable logistic regression was used to model associations of processes of care and without-fail care, defined as receiving all guideline-concordant processes of care for which patients are eligible, with risk of death and recurrent stroke. Data were analyzed from March 2018 to April 2019. Main Outcomes and Measures: Risk of all-cause mortality and recurrent ischemic stroke at 90 days and 1 year was calculated. Overall, 28 processes of care were examined. Without-fail care was assessed for 6 processes: brain imaging, carotid artery imaging, hypertension medication intensification, high- or moderate-potency statin therapy, antithrombotics, and anticoagulation for atrial fibrillation. Results: Among 8076 patients, the mean (SD) age was 67.8 (11.6) years, 7752 patients (96.0%) were men, 5929 (73.4%) were white, 474 (6.1%) had a recurrent ischemic stroke within 90 days, 793 (10.7%) had a recurrent ischemic stroke within 1 year, 320 (4.0%) died within 90 days, and 814 (10.1%) died within 1 year. Overall, 9 processes were independently associated with lower odds of both 90-day and 1-year mortality after adjustment for multiple comparisons: carotid artery imaging (90-day adjusted odds ratio [aOR], 0.49; 95% CI, 0.38-0.63; 1-year aOR, 0.61; 95% CI, 0.52-0.72), antihypertensive medication class (90-day aOR, 0.58; 95% CI, 0.45-0.74; 1-year aOR, 0.70; 95% CI, 0.60-0.83), lipid measurement (90-day aOR, 0.68; 95% CI, 0.51-0.90; 1-year aOR, 0.64; 95% CI, 0.53-0.78), lipid management (90-day aOR, 0.46; 95% CI, 0.33-0.65; 1-year aOR, 0.67; 95% CI, 0.53-0.85), discharged receiving statin medication (90-day aOR, 0.51; 95% CI, 0.36-0.73; 1-year aOR, 0.70; 95% CI, 0.55-0.88), cholesterol-lowering medication intensification (90-day aOR, 0.47; 95% CI, 0.26-0.83; 1-year aOR, 0.56; 95% CI, 0.41-0.77), antithrombotics by day 2 (90-day aOR, 0.56; 95% CI, 0.40-0.79; 1-year aOR, 0.69; 95% CI, 0.55-0.87) or at discharge (90-day aOR, 0.59; 95% CI, 0.41-0.86; 1-year aOR, 0.69; 95% CI, 0.54-0.88), and neurology consultation (90-day aOR, 0.67; 95% CI, 0.52-0.87; 1-year aOR, 0.74; 95% CI, 0.63-0.87). Anticoagulation for atrial fibrillation was associated with lower odds of 1-year mortality only (aOR, 0.59; 95% CI, 0.40-0.85). No processes were associated with reduced risk of recurrent stroke after adjustment for multiple comparisons. The rate of without-fail care was 15.3%; 1216 patients received all guideline-concordant processes of care for which they were eligible. Without-fail care was associated with a 31.2% lower odds of 1-year mortality (aOR, 0.69; 95% CI, 0.55-0.87) but was not independently associated with stroke risk. Conclusions and Relevance: Patients who received 6 readily available processes of care had lower adjusted mortality 1 year after TIA or nonsevere ischemic stroke. Clinicians caring for patients with TIA and nonsevere ischemic stroke should seek to ensure that patients receive all guideline-concordant processes of care for which they are eligible

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

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    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

    Anxiety and depression in Nepal: prevalence, comorbidity and associations

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    BACKGROUND: Anxiety and depression are two important contributors to the global burden of disease. In many developing countries, including Nepal, their prevalences are yet to be assessed. METHODS: A nationwide cross-sectional study was conducted among a representative sample of Nepalese adults aged 18–65 years (N = 2100), selected by multistage random cluster sampling and interviewed at home during unannounced visits. The validated questionnaires included the Hospital Anxiety and Depression Scale (HADS), to detect cases of anxiety (HADS-A), depression (HADS-D) and comorbid anxiety and depression (HADS-cAD), the Eysenck Personality Questionnaire Revised Short Form-Neuroticism (EPQRS-N), and the World Health Organization Quality of Life 8-question scale (WHOQOL-8). Logistic regression analyses were used to explore associations of caseness with four groups of variables: demographic, domicile, substance use, and behavioural and health. RESULTS: Age- and gender-adjusted point prevalences of HADS-A, HADS-D and HADS-cAD were 16.1, 4.2 and 5.9 % respectively. In a multivariate model, HADS-A was positively associated with urban residence (AOR = 1.82; p < 0.001) and neuroticism (AOR = 1.32; p < 0.001), and negatively with alcohol consumption (AOR = 0.71; p = 0.041). HADS-D was positively associated with marijuana use (AOR = 3.61; p = 0.017) and negatively with quality of life (QoL) (AOR = 0.86; p < 0.001). HADS-cAD was positively associated with widowhood (AOR = 2.71; p = 0.002), urban residence (AOR = 2.37; p = 0.001), living at altitude ≥2000 m (AOR = 2.32; p = 0.002) and neuroticism (AOR = 1.26; p < 0.001), and negatively with alcohol use (AOR = 0.56; p = 0.026) and QoL (AOR = 0.79; p < 0.001). CONCLUSION: Depression and anxiety are important mental health conditions in Nepal, and major contributors to public ill health, being very highly prevalent, comorbid and associated with psychosocial burden. They are also linked to the unique topography, habitation and social structure of the country. High prevalence coupled with the disabling nature of these disorders establishes their health-care priority and their importance in national health policy

    Diachronic Study of Phonological Changes in Tiv Language

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    All levels of language analysis are prone to changes in their phonology, morphology, graphology, lexis, semantics and syntax over the years. Tiv language is not an exception to this claim. This study investigates various aspects of phonological or sound changes in Tiv language. This paper therefore classifies sound changes in Tiv; states causes of sound changes in Tiv and explores implications of sound changes. The research design used in this paper is purposive sampling of relevant data. The instrument used in this paper is the observation method in which the author selected words that showed epenthesis, deletion and substitution. It has been noted that the use of archaic spellings in the Modern Tiv literatures shows their ancientness. Phonological change is not a deviation but a sign of language growth and changes in spellings result in changes in sounds. The author recommends that scholars should write papers or critical works on lexical/morphological, syntactic, semantic, graphological changes in Tiv language. Students should write projects, dissertations and theses on language change and diachronic linguistics. This study introduces Tiv historical linguistics and diachronic phonology which serve as catalysts for the study of Tiv language. The understanding of Tiv sound change provides students with a much better understanding of Tiv phonological system in general, of how Tiv phonology works and how the phonemes fit togethe
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