Costs of foraging in a dry tropical environment

This study evaluates the costs associated with foraging for birds in a savannah woodland area in central Nigeria. Specifically, it looks at the following questions: 1) how does seasonal variability in food and water availability affect the value of resources to birds in dry environments? 2) Does proximity to water affect foraging decisions? What implication will this have in the management of savannah birds? 3) Are tropical birds mostly affected by metabolic or predation costs? 4) What factors affect diet selection in birds and how? 5) How are birds adapted to hot dry environments? I carried out experiments in the field and in an aviary and provided artificial food patches, consisting of feeding trays with seeds mixed in sand or pebbles (in the aviary study). I used the giving-up density (GUD; amount of food left in a depletable patch after a foraging bout) of birds as a behavioral indicator and compared GUDs between different microhabitats, varying in levels of predation risk or thermal hazard, across different seasons and between years. In one study, I also placed out water pots to observe the effects of water on foraging, in another I looked at the diet selection strategy of birds offered two seed types differing in energetic content and in another looked at the effect of temperature on birds. Results showed that temporal (seasonal) variations in GUDs appear to be driven by food availability and water while small-scale spatial variation in GUDs seems to be driven by predation risk. Although birds seem to be willing to trade-off food for thermoregulation, they may resort to more costly means of thermoregulation e.g. hyperthermia (elevation of body temperature), when energy demand increases. Also proximity to drinking water will affect the extent to which granivorous birds exploit their environment and the diet selection strategy employed by these birds may be largely dependent on seed quality. My studies have revealed that the behavior observed among animals is shaped by the circumstances they are faced with in their environment. Therefore foraging behavior can be used to evaluate the magnitude and significance of the effects of the different costs associated with a foraging area and may serve as a useful tool in conservation

The functional role of ADAMTS-1 and -15 in prostate cancer progression

Introduction: Prostate cancer is a leading cause of cancer death in men. Death is usually a consequence of castration resistant tumour progression. Some metalloproteinases are implicated in the process of cancer progression. ADAMTS proteinases (A Disintegrin And Metalloproteinase with ThromboSpondin motifs) are metalloproteinases that play diverse roles in tissues. Prostate cancer cells express ADAMTS-1 and -15 but the role played by these proteinases in prostate cancer progression is unknown. This study was designed to determine the role of ADAMTS-1 and 15 in prostate cancer progression. Materials & Methods: Prostate cancer and stromal cell tumour spheroids were grown in 3-dimensional culture in ECM gel containing a quenched-fluorescent substrate. The tumour spheroids were observed for evidence of proteolytic activity. Prostate cancer cells were treated with DHT and TNF. Changes in expression of ADAMTS-1 and -15 were analysed. ADAMTS-1 and -15 expression was knocked-down in PC3 prostate cancer cells and the effect of knock-down on proliferation, migration and invasion was analysed. Results: Tumour spheroids emitted fluorescence after approximately 24 hours in culture, indicating proteolytic activity. DHT and TNF down-regulated ADAMTS-15 expression in LNCaP cells and stromal cells respectively. The validated anti-ADAMTS- 15 antibody detected 50kDa bands, suggesting a novel cleavage site within the disintegrin-like domain of ADAMTS-15. ADAMTS-1 and 15 knock-down had no effect on proliferation, migration or invasion of PC3 prostate cancer cells. Conclusions: Prostate cancer and stromal cells degrade components of the surrounding ECM. ADAMTS-15 but not ADAMTS-1 expression is androgen and TNF-regulated. ADAMTS-1 and 15 expression do not affect the proliferation, migration or invasive potential of PC3 cells in vitro. Cleavage of ADAMTS-15 in the disintegrin-like domain results in the release of a C-terminal fragment with potential anti-angiogenic properties. Down-regulation by DHT in prostate cancer cells suggests that ADAMTS-15 could be playing an anti-tumour role in prostate cancer progression

Links between entrepreneurial orientation and corporate governance structures in the South African oil and gas industry

This study examines the relationships between entrepreneurial orientation (EO) and four sub-dimensions of corporate governance structures (CGS) in a sample of 173 senior decision-makers representing companies in the South African oil and gas industry. The four attributes of CGS include: board effectiveness and competence, board knowledge and experience, board commitment and recognition of complexities and board involvement in decision-making processes. A series of Canonical correlation analyses assess the strength of relationships between the dimensions of EO and CGS at both univariate and multivariate levels. The results of this study support a positive significant relationship between EO dimensions namely, innovation, proactiveness and risk-taking; and the dimensions of CGS namely, board effectiveness and competence, board knowledge and experience, board commitment and recognition of complexities, and board involvement in decision-making processes. It also indicates a positive link between EO and CGS. The synthesis gleaned from this study is based on the expansive literature review on EO and CGS which provided an insight on the existing knowledge on the relevance of EO in organisational growth and CGS with respect to the nature of the boards, executives and decision-makers roles and responsibilities in strategic entrepreneurial activities within the organisation. This study is of practical use to organisations, enabling them to think and act entrepreneurially, and to policy makers to assist them to keep track of the regulatory guidelines, adopted by boards and executives in monitoring and implementing entrepreneurial culture in their respective organisations. Finally, to researchers and academics, this study allows an extension of knowledge to the EO and CGS and its applicability in one distinct industrial context

Assessment of dysphagia in people with Parkinson’s disease, multiple sclerosis and muscular dystrophy

Introduction Previous research has shown that patients with Parkinson’s disease (PD), multiple sclerosis (MS) and muscular dystrophy (MD) are known to be at risk of dysphagia and could benefit from dysphagia screening. The aim of this study was to describe the use of dysphagia screening and assessment procedures amongst patients with neurological conditions when they have an unplanned admission to hospital. Methods Two methods of data collection were used in this study. The first method was a prospective observational study to determine the use of dysphagia screening and assessment procedures amongst patients with Parkinson’s disease, multiple sclerosis and muscular dystrophy. The second, qualitative study examined clinicians’ perceptions of the factors that influenced the decision to screen for dysphagia in people with neurological conditions and the difficulties experienced. Data were collected from clinicians using semi-structured in-depth interviews. Potential interventions to improve the management of dysphagia in these conditions were identified. Results Two hundred patients were recruited to the observational study. Thirty four percent (n=68) of this group underwent a swallow screening assessment (SSA) during the first week of admission and 93% (n=63) of these were judged to have dysphagia. Amongst those who were not assessed initially (n=132), a further 77% (n=101) were found to have dysphagia. Twenty people took part in the interview study including doctors, health care assistants, nurses and therapists. Clinicians reported that the factors which underpinned their decision to screen for dysphagia included pre-existing swallowing difficulties, recognition of symptoms, staff/relative anxiety, communication difficulties and the presenting complaint and diagnosis. However, clinicians reported that their limited knowledge, clinical competencies in swallow screening, a lack of confidence and resources, affected their practice and use of dysphagia screening and assessments. Clinicians noted a number of interventions that could improve the management of dysphagia when patients are admitted to hospital and these included: training in dysphagia screening; development of dysphagia pathways or guidelines; provision of an alert system, introduction of on-call speech and language therapy services; and research funding. Discussions and Conclusions The findings of this study suggest that screening for dysphagia does not occur routinely when patients with neurological conditions are admitted to hospital for an acute condition. This means that opportunities to detect treatable causes of potentially life-threatening complications are being missed. Many inter-related factors were reported to account for this practice and these related primarily to limited knowledge and confidence and the limited accessibility of speech and language therapists outside usual working hours. Interventions to improve routine dysphagia screening should help to reduce the incidence of avoidable complications and perhaps shorten length of stay. Dysphagia pathways or guidelines are needed to support effective management in acute hospital settings

Assessment of dysphagia in people with Parkinson’s disease, multiple sclerosis and muscular dystrophy

Introduction Previous research has shown that patients with Parkinson’s disease (PD), multiple sclerosis (MS) and muscular dystrophy (MD) are known to be at risk of dysphagia and could benefit from dysphagia screening. The aim of this study was to describe the use of dysphagia screening and assessment procedures amongst patients with neurological conditions when they have an unplanned admission to hospital. Methods Two methods of data collection were used in this study. The first method was a prospective observational study to determine the use of dysphagia screening and assessment procedures amongst patients with Parkinson’s disease, multiple sclerosis and muscular dystrophy. The second, qualitative study examined clinicians’ perceptions of the factors that influenced the decision to screen for dysphagia in people with neurological conditions and the difficulties experienced. Data were collected from clinicians using semi-structured in-depth interviews. Potential interventions to improve the management of dysphagia in these conditions were identified. Results Two hundred patients were recruited to the observational study. Thirty four percent (n=68) of this group underwent a swallow screening assessment (SSA) during the first week of admission and 93% (n=63) of these were judged to have dysphagia. Amongst those who were not assessed initially (n=132), a further 77% (n=101) were found to have dysphagia. Twenty people took part in the interview study including doctors, health care assistants, nurses and therapists. Clinicians reported that the factors which underpinned their decision to screen for dysphagia included pre-existing swallowing difficulties, recognition of symptoms, staff/relative anxiety, communication difficulties and the presenting complaint and diagnosis. However, clinicians reported that their limited knowledge, clinical competencies in swallow screening, a lack of confidence and resources, affected their practice and use of dysphagia screening and assessments. Clinicians noted a number of interventions that could improve the management of dysphagia when patients are admitted to hospital and these included: training in dysphagia screening; development of dysphagia pathways or guidelines; provision of an alert system, introduction of on-call speech and language therapy services; and research funding. Discussions and Conclusions The findings of this study suggest that screening for dysphagia does not occur routinely when patients with neurological conditions are admitted to hospital for an acute condition. This means that opportunities to detect treatable causes of potentially life-threatening complications are being missed. Many inter-related factors were reported to account for this practice and these related primarily to limited knowledge and confidence and the limited accessibility of speech and language therapists outside usual working hours. Interventions to improve routine dysphagia screening should help to reduce the incidence of avoidable complications and perhaps shorten length of stay. Dysphagia pathways or guidelines are needed to support effective management in acute hospital settings

Social Network Analysis: A Machine Learning Approach

Social Network Analysis (SNA) is an appealing research topic, within the domain of Artificial Intelligence (AI), owing to its widespread application in the real world. In this dissertation, we have proposed effective Machine Learning (ML) and Deep Learning (DL) approaches toward resolving these open problems with regard to SNA, viz: Breakup Prediction, Link Prediction, Node Classification, Event-based Analysis, and Trend/Pattern Analysis. SNA can be employed toward resolving several real-world problems; and ML as well as DL have proven to be very effective methodologies for accomplishing Artificial Intelligence (AI)- related goals. Existing literature have focused on studying the apparent and latent interactions within social graphs as an n-ary operation, which yields binary outputs comprising positives (friends, likes, etc.) and negatives (foes, dislikes, etc.). Inasmuch as interactions constitute the bedrock of any given Social Network (SN) structure; there exist scenarios where an interaction, which was once considered a positive, transmutes into a negative as a result of one or more indicators which have affected the interaction quality. At present, this transmutation has to be manually executed by the affected actors in the SN. These manual transmutations can be quite inefficient, ineffective, and a mishap might have been incurred by the constituent actors and the SN structure prior to a resolution. Thus, as part of the research contributions of this dissertation, we have proposed an automatic technique toward flagging positive ties that should be considered for breakups or rifts (negative-tie state), as they tend to pose potential threats to actors and the SN. Furthermore, in this dissertation, we have proposed DL-based approaches based on edge sampling strategy for resolving the problems of Breakup Prediction, Link Prediction, and Node Classification. Also, we have proposed ML-based approaches for resolving the problems of Event-based Analysis and Trend/Pattern Analysis. We have evaluated our respective approaches against benchmark social graphs, and our results have been comparatively encouraging as documented herein

Effects of Library Infrastructure on Turnover Intentions of Librarians: A Study of University Libraries in South-South and South-East of Nigeria

Research into the phenomenon of turnover intentions of employees and its effects on organizational development is crucial; hence this study investigated the effects of library infrastructure on turnover intentions of librarians in university libraries in South-South and South-East of Nigeria. The study adopted a descriptive survey using total enumeration method with 400 academic librarians from the two zones in participation. The instrument for data collection was questionnaire which was subjected to a reliability test using Cronbach’s alpha reliability coefficient with a result of 0.72, which means that the instrument was good and reliable since the test result is above the acceptance point of 0.50. All the questionnaires administered on the respondents were retrieved with 334 of the questionnaires found usable for the analysis. Findings revealed that inadequate infrastructure have the tendency of increasing the turnover intentions of librarians in the university libraries in South-South and South East of Nigeria (X = 3.03); while advancement in library infrastructure enhances professional development and increase the chance of retaining librarians in the library (X = 3.05). Evidence from the study indicated that a higher deficiency in library infrastructure will increase the level of turnover intentions of librarians in the university libraries in South-South and South-East of Nigeria. The study recommended that the university librarians and university managements in South-south and South-east of Nigeria should holistically assess their library infrastructure with a view of ascertaining their state and make available budgetary allocation that will take care of dilapidated library infrastructure to mitigate the effects of turnover intentions of librarians in university libraries in South-South and South-East of Nigeria