Microbial influence on intestinal development and mode of action of mannan oligosaccharides in broiler chicken

The effect of intestinal microbiota and dietary supplementation of mannan oligosaccharides (MOS) on mucosal architecture and digestive physiology in broiler chicks was examined. In experiment 1, pre-sterilized eggs (Ross x Ross 308) were placed in three HEPA (high efficiency particulate air)-filtered isolator units at day 19 of incubation. Germ-free chicks in one isolator were conventionalized by exposure to cecal contents from a laying hen. Bacterial contamination occurred in one germ-free isolator such that these birds were monoassociated by a bacterium within the Acinetobacter spp. resulting in 3 categories of microbial status including germ-free (GF, n=10), conventionalized (CV, n=19) and monoassociated (Mono, n=13) birds. Dietary treatments assigned to each isolator consisted of a negative control (NC, 0 g/kg of MOS in the basal diet) and MOS (2 g/kg of MOS in the diet) resulting in a 2X3 factorial treatment arrangement. At 7 d of age, body weight was recorded and birds were killed to permit collection of visceral organs, intestinal tissues and cecal contents. Body weight, relative length of small intestinal segments and relative bursa weight were significantly increased in CV birds. These birds also had increased crypt depth and lamina propria area. Dietary MOS increased villus height and villus surface area in CV birds compared with GF and Mono birds. Transcripts for all housekeeping genes tested in ileal tissue were increased by MOS such that transcripts were normalized to unit mass of total RNA. In comparison to birds fed the NC diet, MOS significantly increased the abundance of proliferative cell nuclear antigen (PCNA), toll-like receptor (TLR)-4, avian β-defensin (GAL)-6, interleukin (IL)-8, peptide transporter 1 (PepT1) and sodium-dependent glucose transporter (SGLT)-1 transcripts in ileum per unit total RNA. However, the effect of microbial status on selected gene expression profiles was surprisingly limited. A second experiment was conducted to confirm the conventionalization protocol produced a complex microbiota similar to conventionally reared birds. Twenty day-old broiler chicks (Ross x Ross 308) were assigned to one of two wire-floored battery cages provided the NC and MOS diets ad libitum and killed at 7 d of age. Terminal restriction fragment length polymorphism (TRFLP) analysis demonstrated that microbial diversity indices (Richness, Evenness, Shannon, and Simpson) were greater in conventionalized gnotobiotic birds compared to the conventionally reared birds confirming a successful conventionalization strategy in the gnotobiotic trial. These studies demonstrate that under good hygienic conditions, CV chicks thrive similar to GF animals. Based on responses to MOS observed in GF birds, evidence indicates that MOS, independent of changes in microbial composition, directly modifies host response parameters including innate immune activation, digestive and absorptive function

A waste minimisation framework for the procurement of design and build construction projects

Both construction Waste Minimisation (WM) and construction procurement activities play an effective role in attaining sustainability by giving due consideration to the environment, community and social conditions in delivering built assets. The construction industry has a major impact on the environment, both in terms of resource consumption and increasing waste production. Recent figures published by the UK government reveal that construction and demolition activities produce approximately 32% of total waste generated: three times the waste produced by all households combined. However, the current and on-going research in the field of construction WM and management focuses mainly on onsite waste quantification and management; and stakeholders‟ source identification. Little research has been undertaken to evaluate the relationship between Construction Procurement Systems (CPS) and construction waste generation. However, literature emphasises the need for research in this context. This research aims to develop a Procurement Waste Minimisation Framework (PWMF) to enhance WM practices by evaluating the relationship between CPS and construction waste generation. Objectives of the research include: examine construction WM drivers, WM approaches, waste origins and causes; critically review and evaluate current CPS and sustainable procurement practices in the UK; assess the relationship between CPS and construction waste generation; investigate and synthesis Procurement Waste Origins (PWO); examine the most suitable CPS that could potentially embed and sustain WM; develop and validate the PWMF. This research has adopted a survey research design and mixed methods sequential procedure. Data has been gathered through a cross sectional, self-administered postal questionnaire survey (N=258 distributed, n=65 received) and semi-structured interviews (N=17) with procurement managers and sustainability managers from the top 100 UK contracting organisations and quantity surveyors from the top 100 UK quantity surveying organisations. Data analysis techniques include: descriptive statistics; non-parametric tests; and constant comparative method. The PWMF has developed based on the findings of literature review, questionnaire survey and semi-structured interviews and adopting key concepts of problem solving methodology. The PWMF validation method includes: validation questionnaire (N=8) and follow-up semi-structured interviews (N=6) with procurement managers, sustainability managers and quantity surveyors. Key findings which emerged from the study include: CPS do have an impact on waste generation in construction; integrated CPS have major potential to integrate WM strategies; four PWO identified (i.e. uncoordinated early involvement of project stakeholders; ineffective communication and coordination; unclear allocation of WM responsibilities; and inconsistent procurement documentation) and associated sub-waste causes; and the developed PWMF enables to diagnose potential waste origins and causes, and WM improvement measures for design and build projects. The study has made recommendations which, if adopted, will lead to significant improvements in WM practices and sustainable procurement practices in construction. The content should be of interest to contractors, clients, and organisations dealing with procurement, waste and sustainability

Perceptions of Climate Change Risk to Forest Ecosystems: A Case Study of Patale Community Forestry User Group, Nepal

The purpose of this study was to investigate perceptions of climate change risk to forest ecosystems and forest-based communities as well as perceived effectiveness of adaptation strategies for climate change as well as challenges for adaptation. Data was gathered using a pre-tested semi-structured questionnaire. Simple random selection technique was applied. For the majority of issues, the responses were obtained on multi-point Likert scales, and the scores provided were, in turn, used to estimate the means and other useful estimates. A composite knowledge index developed using correct responses to a set of self-rated statements were used to evaluate the issues. The mean of the knowledge index was 0.64. Also all respondents recorded values of the knowledge index above 0.25. Increase forest fire was perceived by respondents as the greatest risk to forest eco-system. Decrease access to water supplies was perceived as the greatest risk to livelihoods of forest based communities. The most effective adaptation strategy relevant to climate change risks to forest eco-systems and forest based communities livelihoods in Kathmandu valley in Nepal as perceived by the respondents was reforestation and afforestation. As well, lack of public awareness was perceived as the major limitation for climate change adaptation. However, perceived risks as well as effective adaptation strategies showed an inconsistent association with knowledge indicators and social-cultural variables. The results provide useful information to any party who involve with climate change issues in Nepal, since such attempts would be more effective once the people's perceptions on these aspects are taken into account

Grid-connected converters in hybrid wind-hydrogen systems

The production of hydrogen, facilitated by wind-generated energy, is currently a topic of significant interest among scientists and engineers. One of the arrangements is to connect an electrolyzer to the DC-link of the two converters, which are in a back-to-back configuration between the generator and the grid. The grid-connected converter of this system plays a pivotal role in system operation since it has to handle the dynamical effects of the wind generator, the hydrogen electrolyzer and the grid. This thesis has proposed a suitable control strategy that can be employed in the grid-connected converter of a hybrid wind-hydrogen system. The work commenced with the development of small-signal dynamic models for the wind generator, the hydrogen electrolyzer system and the grid-connected converter. This was followed by the integration of closed-loop dynamics of the wind generator and the hydrogen electrolyzer system into the grid-connected converter model. Next, a control strategy was developed for the grid-connected converter model using linear PI controllers, which was later validated through both software and hardware implementations. Finally, the real test system was presented, and its components, capabilities and limitations were discussed. The incorporation of wind generator and hydrogen electrolyzer dynamics was carried out by obtaining the closed-loop admittance transfer functions of each system model. The operation of the grid-connected converter is dependent on the dynamics of its subsystems due to their interactions. Hence, the DC input current, which the grid-connected converter receives, is dependent on the admittances of the other two subsystems. In this way, the source-affected open-loop transfer functions for the grid-connected converter model could be developed, which can be used for the loop-shaping technique to tune the PI controllers by setting the required stability margins. DC-link voltage regulation and converter current control are among the major objectives of the designed control scheme. The system performance was evaluated under four scenarios in both software and hardware implementations, and the results were observed. The results in all four scenarios depicted that the developed controller can accurately maintain the steady-state operation at both rated and under-rated operating conditions. Furthermore, the converter demonstrated its ability to deal with dynamical impacts caused by sudden changes in the input current by returning to steady-state operation quickly and smoothly. The real test system which is present at the Power Electronics Laboratory of Tampere University, consists of components to emulate wind generation to an extent that is sufficient for most research. However, it lacks the ability to create various grid conditions and reflect the dynamic behavior of wind gusts, turbine blades and the turbine tower

Impact of Wireless Communications Technologies on Elder People Healthcare: Smart Home in Australia

Over the last three decades, there has been a dramatic rise in ageing populations in most countries. Older people remain in nursing home care due to the fact that general services and medical support are provided. However, these environments often negatively affect the occupants due to high cost, limited staff, as well as the social impact they have. A way to overcome these challenges is to place the elderly instead in a Smart Home environment. In other words, by implementing such technology, older people are able to remain at home, instead of going to nursing homes and pay the extremely high fees. The aim of this study is to describe the impact of wireless communications technologies to replace nursing homes with smart homes. Using smart wireless sensors, wireless communication and ambient intelligence systems, it is possible to create systems capable of measuring the vital signs of patients at home. This is based on exchanging signals (information) between sensors and the data server from already deployed sensor equipment (infrared or camera) or wearable smart sensors, allowing older people to stay at home.Over the last three decades, there has been a dramatic rise in ageing populations in most countries. Older people are remaining in nursing home care due to the fact that general services and medical support are provided. However, these environments often negatively affect older people due to high cost, limited staff and the social impacts they have. A way to overcome these challenges is to place the elderly instead of the Nursing Homes in a Smart Home environment. In other words, by implementing such technology, older people are able to remain at home, instead of going to nursing homes and pay the extremely high cost. The aim of this study is to describe the impact of wireless communications technologies on both nursing home and smart home. Using smart wireless sensors, wireless communication and ambient intelligent systems, it is possible to create systems capable of measuring vital signs of the patient at home. This is based on exchanging signals (information) between the sensor and the data server from already deployed sensors (infrared or camera) or wearable smart sensors, allowing older people to stay at home

Identifying the major spilled oil constituents and fate in harsh offshore environments

The behaviour and fate of spilled oil in harsh marine environments, such as the North Atlantic and the Arctic Ocean are complex due to environmental factors and the composition of the crude. In order to develop appropriate oil spill prevention and management methods, we must first understand how the oil behaves in these harsh environmental conditions. This study focuses on determining the fate of oil in harsh marine environments by first identifying target compounds in the oil that can be used to determine the fate of a spill. This thesis presents the partitioning behaviour of six polycyclic aromatic hydrocarbons (PAHs), which represent different groups, and phenols in cold conditions. The smallest PAH, naphthalene, dominated in terms of concentration in water accommodated fraction (WAF) of oil, while the larger ringed PAHs presented at lower concentrations. The smallest oil-water partition coefficient was recorded by phenol which partitioned into the seawater more quickly than PAHs. The partitioning of larger PAHs was slower and they indicated high partition coefficients. The oil partitioning increased slightly as temperature increased from 4ᴼC to 15ᴼC. The oil loading (0.1 g/L to 10 g/L) also contributed in deciding the concentrations in water. The use of chemical dispersants is a common response to spills. This study identified that chemical dispersants can change the fate of an oil spill by increasing the availability of oil in seawater. The concentration of larger PAHs such as pyrene and chrysene increased significantly with the application of dispersants. The information obtained are used in developing a molecular imprinted polymer (MIP) sensor to identify oil spills in the North Atlantic Ocean

A Gamma-frailty proportional hazards model for bivariate interval-censored data

Correlated survival data naturally arise from many clinical and epidemiological studies. For the analysis of such data, the Gamma-frailty proportional hazards (PH) model is a popular choice because the regression parameters have marginal interpretations and the statistical association between the failure times can be explicitly quantified via Kendall’s tau. Despite their popularity, Gamma-frailty PH models for correlated interval-censored data have not received as much attention as analogous models for right-censored data. A Gamma-frailty PH model for bivariate interval-censored data is presented and an easy to implement expectation–maximization (EM) algorithm for model fitting is developed. The proposed model adopts a monotone spline representation for the purposes of approximating the unknown conditional cumulative baseline hazard functions, significantly reducing the number of unknown parameters while retaining modeling flexibility. The EM algorithm was derived from a data augmentation procedure involving latent Poisson random variables. Extensive numerical studies illustrate that the proposed method can provide reliable estimation and valid inference, and is moreover robust to the misspecification of the frailty distribution. To further illustrate its use, the proposed method is used to analyze data from an epidemiological study of sexually transmitted infections

The performing artistes in Sri Lanka: the contribution to ethno-religious cohesion through their shaping and challenging of socio-cultural norms.

Mahāvaṃsa, the most widely cited historical Pali chronicle, records information about the performing arts of the Yaksha and Naga tribes who lived even before the advent of Vijaya to Sri Lanka in 543 BCE. With the introduction of Buddhism and Hinduism to Sri Lanka (250 BCE), ritual and religious based ceremonies inspired by India developed and the performing artiste played a significant role in those ceremonies. Because of the subjugation of Sri Lanka to Portuguese rule in 1505, the Dutch in 1658 and the British in 1815 several changes took place in Sri Lankan art. With the Sinhalese-Buddhist policy declared in 1956, the main ethnic groups of Sinhalese and Tamil separated into two distinct groups with the result that a civil war lasting more than twenty-five years ensued. Along with this, the performing arts divorced itself from the common ethnic background and separated into two as Sinhalese and Tamil. Thus, this thesis will primarily focus its attention on the role and influence of Sinhalese-Buddhist and Tamil-Hindu artistes on key issues such as caste, ethnicity and gender in ethno-religious division. Similarly, the manner in which the performing artiste overcomes ethnicity and gender issues through the practice of his/her art caste, and the contribution this has made to the establishment of ethno-religious cohesion in society at large is also examined