4,291 research outputs found
Production and marketing of milkfish in Taiwan: an economic analysis
A study of the whole Taiwanese milkfish industry from fry gathering to marketing. Based on a survey of over 200 respondents.Fish culture, Aquaculture economics, Marketing, Milkfish culture, Milkfish industry, Taiwan, Chanos chanos
Histological Changes in the Pregnant, Lactating and Involuting Mammary Gland of the Guinea Pig
The histological changes of mammary glands of guinea pigs during mid and late pregnancy, 1
day after parturition, peak lactation and 2, 3, 4, 8 and 12 days after weaning were studied. Rapid
growth of the glandular tissue occurred towards late pregnancy and was completed by peak lactation.
Plasma cells occurred in large numbers in the interalveolar connective tissue during the period between
mid-pregnancy and lactation. Mammary involution was an autolytic process aided by the action
of macrophages accompanied by shrunken alveoli and increased interalveolar connective tissue. This
feature was evident at 3 days after weaning which began from the periphery of the glands. The
number of macrophages were abundant in the connective tissue and alveolar and ductal lumina. By
day 8, the alveoli were no longer recognisable and at 12 days after weaning only remnants of ductules
and alveoli were present
On One Aspect of Science Policy Based on an Uncertain Model
We discuss one aspect of the allocation of new scientists to teaching and research careers. In the past, this allocation problem was treated on the basis of a model with known constant parameters and as a classical open-loop optimal control problem with the allocation ratio as the sole control variable. The utility function in that treatment took both short term and long term goals into account. Here we allow for uncertainty in the possibly time-varying system parameters, and we account for the possibility of new scientists going into careers other than teaching and research. We treat the allocation problem not as an optimal control one but rather as one robust control, insensitive to uncertainties, in order to assure desired numbers of teachers and scientists within a computable horizon
Measurement of in semi-inclusive charmless decays
We study semi-inclusive charmless decays , where does not
contain a charm (anti)quark. The mode turns out to be be
particularly useful for determination of the CKM matrix element . We
present the branching ratio (BR) of as a function of
, with an estimation of possible uncertainty. The BR is expected to
be an order of .Comment: 3 pages, 2 figures, Proceedings of the Fifth KEK Topical Conferenc
Cross-Scene Trajectory Level Intention Inference using Gaussian Process Regression and Naive Registration
Human intention inference is the ability of an artificial system to predict the intention of a person. It is important in the context of human-robot interaction and homeland security, where proactive decision making is necessary. Human intention inference systems at test time is given a partial sequence of observations rather than a complete one. At a trajectory level, the observations are 2D/3D spatial human trajectories and intents are 2D/3D spatial locations where these human trajectories might end up. We study a learning approach where we train a model from complete spatial trajectories, and use partial spatial trajectories to test intention predictions early and accurately. We use non-parametric Gaussian Process Regression (GPR) as the learning model since GPR has been shown to model subtle aspects of human trajectory very well. We also develop a simple geometric transfer technique called Naive Registration (NR) that allows us to learn the model using training data in a source scene and then reuse that model for testing data in a target scene. Our results on synthetic and real data suggests that our transfer technique achieves comparable results as the technique of training from scratch in the target scene
Search for New Physics in the Semileptonic D_{l4} Decays, D->K \pi l \nu
New physics effects through the direct CP violation and the decay rate change
are investigated in the semileptonic decays, , by including a scalar-exchange interaction with a complex coupling. In
the decay process, we included various excited states as intermediate states
decaying to the final hadrons, , and found that among the intermediate
states only the lowest state () is dominant and the other higher excited
states are negligible, contrary to the decays. We also obtained
constraints on the new complex coupling within the multi-Higgs doublet model
and the scalar leptoquark models.Comment: LaTeX, 16 pages, including 3 figure
Electrical technology students in vocational colleges: are they healthy mentally?
Distraction such as depression, anxiety, and stress in mental health problem can influence academic achievement to students, including vocational colleges’ students. Hence, the main purpose of this study was to determine the mental health profiles of Electrical Course students in Vocational Colleges. The difference in mental health level in terms of gender, hometown, and years of study were also be investigated. Besides, the level of mental health elements implementation by teachers in teaching and learning was also determined. This study was employed a survey method as research design that involved of 132 respondents from three vocational colleges in the southern zone. The respondents were selected using strata sampling technique. The instrument of this study was Malay version DASS-21 item inventory. This inventory measures three elements of mental health problem, namely depression, anxiety, and stress through 21 items. Questionnaires for level of mental health elements implementation by teachers in teaching and learning from student perception consists of 21 items. The collected data were analyzed using frequency, percentage, Spearman Rho test, Mann Whitney U test, and Kruskal Wallis test. The findings of this study showed that students' mental health level and the level of mental health elements implementation by teachers in teaching and learning were at the moderate level. The findings also found that there was a significant relationship between each element of mental health with students’ academic achievement level, as well as the level of mental health elements implementation by teachers in teaching and learning. In addition, the results also shows that there were no significant difference in the mental health level among the students from the aspects of gender, hometown, and years of study. In short, an intervention program needs to be implemented to overwhelm students’ mental health problems, because prevention was better than cure
An initial study on the influences of problem solving in children's learning
Researchers have advocated problem solving to induce learners in conceptual change process as problem representation is central to whether or not learners achieve the intended change [1]. One way to help learners develop their problem representations is through tools that will enable them to externalize problem representations [2] and this can be done by encouraging learners to build dynamic models of the real world systems as it not only supports problem solving but also the transfer of knowledge. This study which included a sample size of 70 fifth grade students was conducted in a public elementary school in two science classrooms. Students who received the treatment were given an ill-structured problem to solve by building dynamic system models as a form of external representation. Quantitative data were collected through a pre and post test quasi experimental design. Responses from Knowledge Tests and Problem Solving Skills Tests were pilot tested for reliability prior to the actual study. Results gained from the pre and post tests showed that students who had gone through the problem solving activity achieved better conceptual understanding on the two main concepts of the water cycle-evaporation and condensation than those who were not given the treatment. This group of students also managed to build more sophisticated conceptual models. This suggest that a problem solving environment may enable students to develop or activate their problem solving skills and enabled them to see the value of meaning making in science
Biological Invasions: The Case of Soybean Aphid Infestation
Soybeans, the second highest cash crop following corn in the U.S., have come under attack by invasive species, the soybean aphid from the North and soybean rust from the South. We estimated the economic losses resulting from soybean aphid infestation by using a dynamic equilibrium model. Results indicate that, first, the reduction of soybean production resulting from soybean aphid infestation is largely absorbed by reducing soybean exports, due to the higher price elasticity of export demand compared to the domestic demand. Second, the economic losses to U.S. soybean producers would grow on average annually between 23.4 million during the first five years of infestation. In the longer-run, soybean producers would suffer greater economic losses as the dispersion rate of infested soybean acreage with soybean aphids rises. However, the successful discovery of the soybean aphid gene (TF04048) Rag-1 (which confers resistance) does not at this time warrant soybean growers and policy-makers becoming too seriously alarmed. Even so, time is an important factor in the eventual control of the soybean aphid.Crop Production/Industries,
Economic Impacts of the U.S. Soybean Aphid Infestation: A Multi-Regional Competitive Dynamic Analysis
We estimated the economic benefits resulting from controlling soybean aphid infestation by using a multi-regional competitive dynamic equilibrium model. Results indicate that the reduction of soybean production resulting from a soybean aphid infestation is largely absorbed by reducing soybean exports, due to the higher price elasticity of export demand compared to domestic demand. Producer benefits resulting from controlling soybean aphids would increase by between 1.623 billion in ten years under various scenarios. Results also suggest that it is economically more efficient to control soybean aphids when the rate of intrinsic growth is relatively lower, the supply price elasticity of soybean acreage is relatively more elastic, and insecticide treatment costs per acre are lower. However, if the discovery of the gene Rag-1 (TF04048) leads to new cultivars that withstand the soybean aphid, our estimates will overestimate the actual damages. Even so, our analysis demonstrates that it is critical to control soybean aphids early in their infestation cycle to avoid a rapid increase in damages.soybean aphid, invasive species, producer surplus, consumer surplus, Rag-1, Crop Production/Industries,
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