9,798 research outputs found
Effect of Acacia tortilis pods on intake, digestibility and nutritive quality of goat diets in southwestern Eritrea
Fresh Acacia tortilis pods were mixed with low quality native grass hay to form the following five rations: 100% hay (T 1), 25% pods and 75% hay (T 2), 50% pods and 50% hay (T 3), 75% pods and 25% hay (T 4) and 100% pods (T 5) on ‘as fed’weight basis. Fifteen male Barka goats, approximately one year old and 10–15kg body weight, were randomly assigned to the five rations and fed in individual pens. Chemical composition, dry matter intake (DMI), in vitro dry and organic matter digestibility and body weight changes of the animals were evaluated. The average crude protein content of the pods was about 47% higher than the 7% minimum required for normal rumen function, while that of the hay was about 13% below. Percent ash, neutral detergent fibre (NDF), acid detergent fibre (ADF), hemi-cellulose (HC), cellulose (CL) and acid detergent lignin (ADL) contents were higher in the hay than in the pods. The pods were, however, generally higher in Ca, P, Mg and Na than the hay. Average DMI (g d -1 and g kg-1 LBW), percent in vitro dry and organic matter digestibility and body weight gains (total kg and gd -1) increased with an increase in A. tortilis pods, up to 75% level and then begun to decline. However, despite the decrease, T 5 still had significantly (P< 0.05) higher feed digestibility and body weight gains than T 2 and T3. Thus, supplementing low quality range herbage with Acacia pods can considerably improve the nutritive value of range livestock diets, particularly during the dry season when other types of fodder are of extremely low quality
Study of perturbed periodic systems of differential equations - The Stroboscopic method
Stroboscopic method for solving perturbed periodic systems of differential equation
MECHANICAL LOADING OF THE LUMBAR SPINE OF ELITE ROWERS WHILE ROWING FIXED AND SLIDING ERGOMETERS
Low back injury is common in rowers. This study compared compressive forces of the lumbar spine, while rowing on fixed and sliding ergometers. Fifteen elite male rowers with no history of serious low back injury rowed the Concept2 Fixed (C2F), Concept2 Sliding (C2S) and RowPerfect (RP) ergometers at 32 strokes/min while 3D motion and external force data were recorded. Inverse dynamics analysis was used to find net lumbar moment and a lumbar model used to model compressive forces acting at L4/L5. Compressive force was significantly larger on C2F, at the catch and for 45 % of the stroke. Rowing on the C2F ergometer places greater compressive stress on the lumbar spine
Colonization of malaria vectors under semi-field conditions as a strategy for maintaining genetic and phenotypic similarity with wild populations
Background
Malaria still accounts for an estimated 207 million cases and 627,000 deaths worldwide each year. One proposed approach to complement existing malaria control methods is the release of genetically-modified (GM) and/or sterile male mosquitoes. As opposed to laboratory colonization, this requires realistic semi field systems to produce males that can compete for females in nature. This study investigated whether the establishment of a colony of the vector Anopheles arabiensis under more natural semi-field conditions can maintain higher levels of genetic diversity than achieved by laboratory colonization using traditional methods.<p></p>
Methods
Wild females of the African malaria vector An. arabiensis were collected from a village in southern Tanzania and used to establish new colonies under different conditions at the Ifakara Health Institute. Levels of genetic diversity and inbreeding were monitored in colonies of An. arabiensis that were simultaneously established in small cage colonies in the SFS and in a large semi-field (SFS) cage and compared with that observed in the original founder population. Phenotypic traits that determine their fitness (body size and energetic reserves) were measured at 10th generation and compared to founder wild population.<p></p>
Results
In contrast to small cage colonies, the SFS population of An. arabiensis exhibited a higher degree of similarity to the founding field population through time in several ways: (i) the SFS colony maintained a significantly higher level of genetic variation than small cage colonies, (ii) the SFS colony had a lower degree of inbreeding than small cage colonies, and (iii) the mean and range of mosquito body size in the SFS colony was closer to that of the founding wild population than that of small cage colonies. Small cage colonies had significantly lower lipids and higher glycogen abundances than SFS and wild population.<p></p>
Conclusions
Colonization of An. arabiensis under semi-field conditions was associated with the retention of a higher degree of genetic diversity, reduced inbreeding and greater phenotypic similarity to the founding wild population than observed in small cage colonies. Thus, mosquitoes from such semi-field populations are expected to provide more realistic representation of mosquito ecology and physiology than those from small cage colonies.<p></p>
A Proof of Concept Study on Utilising a Non-invasive Microwave Analysis Technique to Characterise Silver Based Materials in Aqueous Solution
This paper reports on the feasibility of using a novel and robust microwave sensing technique to analyse and detect silver materials in an aqueous solution. Two products are tested, namely: silver chloride and silver oxide. The study mainly focused on indicating the difference between them and also any change in the size/size distribution of the sample. A microwave sensor designed previously is utilised to identify the potential of the technique to carry out the analysis. The results are presented as microwave spectrums that are the material response to microwaves. The results have shown that the technique has reasonably indicated the change in material type as well as size distribution. The results also show that these curves are distinguishable and can be related to the material and the change in its size. It is concluded that there is a potential of extending this technique to determine various other properties of silver products. The study suggests a design and development of a bespoke unit as a dedicated analysis tool and to address any anomalies arising from the current feasibility. This will have a huge industrial benefit in terms of cost reduction and time associated with the industrial analysis of silver material
Disney\u27s Internship Program: More than Hands-On Experience
The vast majority of hospitality management programs require students to participate in a hands-on work experience, which helps bridge the gap between theory and practice, providing the student with an opportunity to practice the theory learned in the classroom. The Walt Disney World Co. developed, implemented, and operates one of the most successful internship programs in the hospitality industry. It recognizes the need for business practitioners to become more involved in the education of future hospitality managers. The authors summarize the company\u27s program and offer suggestions for other employers looking to give interns more than hands-on experience
Tendency to contact general practice instead of self-care : a population vignette study
Background: Demand for general practice in the UK is higher than supply. Some patients seek appointments with GPs for minor illnesses rather than self-care.
Aim: To identify the characteristics of people with a tendency to contact GPs rather than self-care.
Design & setting: A national survey of the British adult population was undertaken in 2018, which included vignettes.
Method: Two vignettes focused on illness in adults: half of responders completed a vignette about cough and sore throat for 3 days, and the other half completed a vignette about diarrhoea and vomiting for 2 days. Logistic regression was undertaken to identify characteristics associated with contacting GPs compared with dealing with the problem themselves, calling NHS 111, or contacting another service, including a pharmacist.
Results: The response rate was 42%, with 2906 responders. Responders were twice as likely to select ‘contact GP’ for the diarrhoea and vomiting vignette than for the cough and sore throat vignette (44.7% versus 21.8%). Factors associated with tendency for GP contact included being aged >75 years (odds ratio [OR] 2.0, 95% confidence interval [CI] = 1.2 to 3.2); from black, Asian and minority ethnic (BAME) communities (OR 2.1, 95% CI = 1.5 to 3.0); feeling overwhelmed by unexpected health problems (OR 1.4, 95% CI = 0.99 to 2.1); lower health literacy (OR 1.2, 95% CI = 1.0 to 1.4); and believing that general practice is not overused (OR 1.3, 95% CI = 1.1 to 1.7).
Conclusion: Type of symptom, personal characteristics, and population beliefs about general practice utilisation explain the tendency to contact GPs for minor illness amenable to self-care
Quantum Computing and Hidden Variables I: Mapping Unitary to Stochastic Matrices
This paper initiates the study of hidden variables from the discrete,
abstract perspective of quantum computing. For us, a hidden-variable theory is
simply a way to convert a unitary matrix that maps one quantum state to
another, into a stochastic matrix that maps the initial probability
distribution to the final one in some fixed basis. We list seven axioms that we
might want such a theory to satisfy, and then investigate which of the axioms
can be satisfied simultaneously. Toward this end, we construct a new
hidden-variable theory that is both robust to small perturbations and
indifferent to the identity operation, by exploiting an unexpected connection
between unitary matrices and network flows. We also analyze previous
hidden-variable theories of Dieks and Schrodinger in terms of our axioms. In a
companion paper, we will show that actually sampling the history of a hidden
variable under reasonable axioms is at least as hard as solving the Graph
Isomorphism problem; and indeed is probably intractable even for quantum
computers.Comment: 19 pages, 1 figure. Together with a companion paper to appear,
subsumes the earlier paper "Quantum Computing and Dynamical Quantum Models"
(quant-ph/0205059
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