Production Performance of Indigenous Chicken under Semi Intensive Management Conditions in Central Tanzania

A study to evaluate four indigenous chicken – namely: Horasi, Kuchi, Naked neck and Frizzled in order to obtain grand-parent and parent stocks was carried out at Tanzania Livestock Research Institute, Mpwapwa district of Dodoma, Tanzania. The perfomance of the ecotypes were compared so as to come out with the best indigenous chicken among the four. A total of 548 indigenous chicken including Horasi (162), Kuchi (253), Naked neck (81) and Frizzled (52) were used in the study. All chicken were treated equally in terms of management under semi intensive system. Data were collected on body weight, external egg characteristics, day old chick weight, body weight gain, weight at 4, 8, 12, 16, 20, 24 weeks of age for each ecotype. Age at first egg and egg number were also determined. The collected data was analysed using General Linear Model of SAS (2006). The results showed that there were significant differences in mature body and egg weight between the ecotypes. The mature body weight and egg weight respectively were 2075g, 2070g, 1792g , 1622g and 44.73g, 45.94g, 38.28g, 38.08g for Horasi, Kuchi, Naked neck and Frizzled respectively. Day old chick weight were 34.26g, 36.26g, 31.99g and 29.02g for Horasi, Kuchi, Naked neck and Frizzled respectively. Average growth rate per day in grams for Horasi and Kuchi was 3.67g and 3.96g per day from day old chick to week 4 and 6.83g and 8.25g per day from week 5 to week 8, respectively. Average egg numbers per clutch for Horasi and Naked neck were 16 and 18 eggs respectively. Average body weight at week 24 for naked neck and Horasi (F1) were 1427g and 1572.8g respectively. Average ages at first egg for Horasi and Naked neck (F1) were found to be 15 weeks and 16 weeks, respectively. The study reveals that, Horasi and Naked neck ecotypes under semi intensive system perform better than Frizzed. It was conclude that, Horasi and Naked neck can be used at farm level for egg production and Kuchi could be used to improve meat production on other indigenous chicken hence increase income of smallholder farmers

Change and Aging Senescence as an adaptation

Understanding why we age is a long-lived open problem in evolutionary biology. Aging is prejudicial to the individual and evolutionary forces should prevent it, but many species show signs of senescence as individuals age. Here, I will propose a model for aging based on assumptions that are compatible with evolutionary theory: i) competition is between individuals; ii) there is some degree of locality, so quite often competition will between parents and their progeny; iii) optimal conditions are not stationary, mutation helps each species to keep competitive. When conditions change, a senescent species can drive immortal competitors to extinction. This counter-intuitive result arises from the pruning caused by the death of elder individuals. When there is change and mutation, each generation is slightly better adapted to the new conditions, but some older individuals survive by random chance. Senescence can eliminate those from the genetic pool. Even though individual selection forces always win over group selection ones, it is not exactly the individual that is selected, but its lineage. While senescence damages the individuals and has an evolutionary cost, it has a benefit of its own. It allows each lineage to adapt faster to changing conditions. We age because the world changes.Comment: 19 pages, 4 figure

Electroweak Gauge-Boson Production at Small q_T: Infrared Safety from the Collinear Anomaly

Using methods from effective field theory, we develop a novel, systematic framework for the calculation of the cross sections for electroweak gauge-boson production at small and very small transverse momentum q_T, in which large logarithms of the scale ratio M_V/q_T are resummed to all orders. These cross sections receive logarithmically enhanced corrections from two sources: the running of the hard matching coefficient and the collinear factorization anomaly. The anomaly leads to the dynamical generation of a non-perturbative scale q_* ~ M_V e^{-const/\alpha_s(M_V)}, which protects the processes from receiving large long-distance hadronic contributions. Expanding the cross sections in either \alpha_s or q_T generates strongly divergent series, which must be resummed. As a by-product, we obtain an explicit non-perturbative expression for the intercept of the cross sections at q_T=0, including the normalization and first-order \alpha_s(q_*) correction. We perform a detailed numerical comparison of our predictions with the available data on the transverse-momentum distribution in Z-boson production at the Tevatron and LHC.Comment: 34 pages, 9 figure

Chromatic Illumination Discrimination Ability Reveals that Human Colour Constancy Is Optimised for Blue Daylight Illuminations

The phenomenon of colour constancy in human visual perception keeps surface colours constant, despite changes in their reflected light due to changing illumination. Although colour constancy has evolved under a constrained subset of illuminations, it is unknown whether its underlying mechanisms, thought to involve multiple components from retina to cortex, are optimised for particular environmental variations. Here we demonstrate a new method for investigating colour constancy using illumination matching in real scenes which, unlike previous methods using surface matching and simulated scenes, allows testing of multiple, real illuminations. We use real scenes consisting of solid familiar or unfamiliar objects against uniform or variegated backgrounds and compare discrimination performance for typical illuminations from the daylight chromaticity locus (approximately blue-yellow) and atypical spectra from an orthogonal locus (approximately red-green, at correlated colour temperature 6700 K), all produced in real time by a 10-channel LED illuminator. We find that discrimination of illumination changes is poorer along the daylight locus than the atypical locus, and is poorest particularly for bluer illumination changes, demonstrating conversely that surface colour constancy is best for blue daylight illuminations. Illumination discrimination is also enhanced, and therefore colour constancy diminished, for uniform backgrounds, irrespective of the object type. These results are not explained by statistical properties of the scene signal changes at the retinal level. We conclude that high-level mechanisms of colour constancy are biased for the blue daylight illuminations and variegated backgrounds to which the human visual system has typically been exposed

A pattern of care analysis: Prosthetic rehabilitation of head and neck cancer patients after radiotherapy

Background While some medical associations provide guidelines for the implant‐prosthetic rehabilitation of head and neck cancer patients, the circulation and implementation in the everyday routine of practicing dentists remain unknown. Purpose To analyze patterns of care for the prosthetic rehabilitation of head and neck cancer patients after radiotherapy in German speaking countries. Materials and methods An online survey consisting of 34 questions separated into three sections, (a) general inquiries, (b) treatment concepts, and (c) patient cases, was forwarded to university hospital departments for Prosthetic Dentistry and Oral and Maxillofacial Surgery, and members of different medical associations. Statistical differences between groups were analyzed using chi‐squared test (P < .05). Results From May to October 2019, 118 participants completed the survey. The majority practiced in university hospitals, had more than 5 years of work experience, and reported to be involved in <10 post radiation prosthetic rehabilitation cases per year. Rehabilitation protocols involving dental implants were implemented by oral/oral‐ and maxillofacial surgeons and prosthetic dentists, while general dentists favored implant‐free solutions. Xerostomia was recognized as a common problem for a successful prosthetic rehabilitation. The subsequent treatment choice with either fixed dental prostheses or removable dentures was divided among participants. Conclusions As treatment planning differed with regard to the participants' field of expertise and work environment, and most practitioners only handle a low number of cases, patients might benefit from centralization in larger institutes with a multidisciplinary structure. A high agreement between the practitioners' treatment concepts and the current state of research was observed. While the choice between a mucosa‐ or tooth‐supported, and an implant‐supported restoration depends on numerous individual factors, guidelines derived from longitudinal studies would enhance evidence‐based treatment in this field

Strengthening of three-leaf stone masonry walls: an experimental research

The paper summarizes the results of an experimental research carried out on three-leaf masonry walls of typical granite stone constructions from the North of Portugal. The research aimed at studying the behaviour under compression of this wall typology, as well as the improvements introduced by common strengthening techniques applied for the structural rehabilitation of masonry heritage buildings. Ten masonry specimens were tested, plain or strengthened by transversal tying of the external leaves, with GFRP bars, or/and by injection of the inner leaf, with a lime-based grout. The results obtained showed that these strengthening techniques were successful in increasing the compressive strength of the walls and in improving their behaviour under compressive loads.The authors would like to thank the technical staff of the Structural Laboratory of University of Minho for the help provided. Acknowledgements are also due to the companies Fradical, Mapei and Augusto de Oliveira Ferreira for providing raw materials and workmanship. Finally, the funding provided by the Portuguese Science and Technology Foundation, through the POCI/ECM/58987/2004 project, is gratefully acknowledged

Economic Feasibility of a New Method to Estimate Mortality in Crisis-Affected and Resource-Poor Settings

INTRODUCTION: Mortality data provide essential evidence on the health status of populations in crisis-affected and resource-poor settings and to guide and assess relief operations. Retrospective surveys are commonly used to collect mortality data in such populations, but require substantial resources and have important methodological limitations. We evaluated the feasibility of an alternative method for rapidly quantifying mortality (the informant method). The study objective was to assess the economic feasibility of the informant method. METHODS: The informant method captures deaths through an exhaustive search for all deaths occurring in a population over a defined and recent recall period, using key community informants and next-of-kin of decedents. Between July and October 2008, we implemented and evaluated the informant method in: Kabul, Afghanistan; Mae La camp for Karen refugees, Thai-Burma border; Chiradzulu District, Malawi; and Lugufu and Mtabila refugee camps, Tanzania. We documented the time and cost inputs for the informant method in each site, and compared these with projections for hypothetical retrospective mortality surveys implemented in the same site with a 6 month recall period and with a 30 day recall period. FINDINGS: The informant method was estimated to require an average of 29% less time inputs and 33% less monetary inputs across all four study sites when compared with retrospective surveys with a 6 month recall period, and 88% less time inputs and 86% less monetary inputs when compared with retrospective surveys with a 1 month recall period. Verbal autopsy questionnaires were feasible and efficient, constituting only 4% of total person-time for the informant method's implementation in Chiradzulu District. CONCLUSIONS: The informant method requires fewer resources and incurs less respondent burden. The method's generally impressive feasibility and the near real-time mortality data it provides warrant further work to develop the method given the importance of mortality measurement in such settings

Targeting breast cancer stem cells: fishing season open!

Studies describing the tumor as a hierarchically organized cell population have changed the classical oncogenesis view and propose new therapeutic strategies. Cancer stem cells (CSCs) are thought to sustain tumor initiation/maintenance, therapy resistance, and systemic metastases. Targeting this tumor cell population is crucial to achieve a true cancer cure. A large research effort is now aiming to develop drugs targeting CSCs, based either on a priori understanding of key pathways regulating CSC biology or on high-throughput screening to identify novel targets and compounds

Cytogerontology since 1881: A reappraisal of August Weismann and a review of modern progress

Cytogerontology, the science of cellular ageing, originated in 1881 with the prediction by August Weismann that the somatic cells of higher animals have limited division potential. Weismann's prediction was derived by considering the role of natural selection in regulating the duration of an organism's life. For various reasons, Weismann's ideas on ageing fell into neglect following his death in 1914, and cytogerontology has only reappeared as a major research area following the demonstration by Hayflick and Moorhead in the early 1960s that diploid human fibroblasts are restricted to a finite number of divisions in vitro. In this review we give a detailed account of Weismann's theory, and we reveal that his ideas were both more extensive in their scope and more pertinent to current research than is generally recognised. We also appraise the progress which has been made over the past hundred years in investigating the causes of ageing, with particular emphasis being given to (i) the evolution of ageing, and (ii) ageing at the cellular level. We critically assess the current state of knowledge in these areas and recommend a series of points as primary targets for future research