• Asian-Australasian Journal of Animal Sciences
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• v.15 no.6
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• pp.866-871
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• 2002

An experiment was conducted at the experimental duck farm of Cantho University to determine the effects of feeding duckweed (Lemna minor) that replaced commercial protein supplements in diets for local and Cherry Valley breeding ducks. The experiment included a total of 180 ducks, with five treatments and three replicates and six breeding ducks (one male plus five females together) per replicate, for both local and exotic Cherry Valley ducks. The five diets were fed ad libitum and were based on rice byproducts supplemented with roasted soya bean meal plus dried fishmeal at levels of 100% (SF100, control), 75 (SF75), 50 (SF50), 25 (SF25) or zero (SF0) % of the protein in the control diet, corresponding to 18, 15, 13, 10 and 8% CP in the diets for both breeds, respectively. Fresh duckweed was supplied ad libitum for all treatments. These diets were fed to local breeding ducks from 7 to 12 months of age, and to exotic breeding ducks (Cherry Valley) from 8 to 13 months of age. Total mean daily dry matter (DM) intakes were 183, 178, 176, 177 and 174 g (p<0.05) for the local ducks, and 221, 208, 215, 219 and 210 g (p<0.01) for the exotic ducks for the SF100 (control), SF75, SF50, SF25 and SF0 diets, respectively. Laying rates of the local ducks were 66.5, 65.2, 62.9, 63.1 and 62.3%, and of the Cherry Valley ducks 61.9, 58.4, 58.9, 59.1 and 53.5% (p<0.001) for the control (SF100), SF75, SF50, SF25 and SF0 treatments, respectively. Fertile egg rates were 95.6, 95.6, 97.8, 97.8 and 92.2%, and hatchabilities 89.4, 80.6, 87.2, 88.6 and 77.8% (p<0.05) for the local breed, and 97.8, 97.8, 91.1, 92.2 and 90.0% (p<0.05) and 72.8, 74.7, 75.0, 74.3 and 76.7% for the Cherry Valley ducks for diets SF100, SF75, SF50, SF25 and SF0, respectively. Corresponding feed conversion ratios (dry matter basis) were 3.83, 3.82, 3.89, 4.01 and 3.96 kg feed per kg egg mass for the local ducks and 4.52, 4.56, 4.58, 4.73 and 5.02 kg feed per kg egg mass for the Cherry Valley ducks for the SF100, SF75, SF50, SF25 and SF0 treatments, respectively. Replacement of 100% of the protein supplement by fresh duckweed in the diets of the local laying ducks decreased the feed costs by 25% compared to the control diet.

• Korean Institute of Interior Design Journal
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• v.20 no.6
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• pp.300-310
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• 2011

Recently, a new paradigm for the change in recognition on educational spaces and their recycling has been spotlighting a concept of community school. However in Korea, there have been few changes in physical environment since the modern education started, due to the inconsistent educational policies and bungled administration. In contrast to Korea, Netherlands has been activating educational spaces to communicate with the local community, reacting to the change in several educational policies for the last 20 years. We, therefore, need to analyze the recent community school of Herman Hertzberger who starting with the Montessori School, came to the fore with a proposal of new relational educational spaces. For linking his relational architectural philosophy to the local community and community school, he applied it to a contact area. He then organized socially sustainable spaces to promote different acts to take place, laying stress on mutual forms and behaviors between spaces and spaces, spaces and people and people and people. In addition to a structural relation with the macroscopic community of architecture, he also created opened spaces, not those where are independent or disconnected, by encouraging users to meet and act in detailed components such as stairs, walls, windows and others. This study aims to consider how Hertzberger's various community spaces in the community school have been created after the 2000s and suggest design plans for educational spaces to communicate, according to the recent educational trend aspiring towards open education.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1211-1216
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• 2011

Sexual maturity in poultry is controlled by a complex neural circuit located in the basal forebrain, which integrates the central and peripheral signals to activate hypothalamic gonadotrophin-releasing hormone (GnRH) secretion. This study demonstrated the changes of GnRH-I, POMC and NPY mRNA transcription in hypothalamus and IGF-I and leptin levels in serum of Shaoxing ducks during puberty. Body weight increased progressively from d30 to d120 and at d120 the flock reached 5% of laying rate. A significant upregulation of hypothalamic GnRH-I mRNA expression was observed from d60, reaching the peak at d120. POMC and NPY mRNA expression in hypothalamus showed a similar pattern, which increased from d30 to d60, followed by a significant decrease towards sexual maturity. Serum IGF-I levels exhibited two peaks at d30 and d120, respectively. Serum leptin displayed a single peak at d90. The results indicate that the down-regulation of POMC and NPY genes in hypothalamus coincides with the up-regulation of GnRH-I gene to initiate sexual maturation in ducks. In addition, peripheral IGF-I and leptin may relay the peripheral metabolic status to the central system and contribute to the initiation of the reproductive function in ducks.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.533-540
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• 1999

We observed that the thick outer bark layer of Quercus variabilis hindered oak longicorn beetle (Moechotypa diphysis) from laying its eggs in inner bark (secondary phloem tissues). The outer bark thickness of Q. variabilis was average of 7.4mm, while those of Q. mongolica. Q. serrata and Q. acutissima were average of 1.1mm, 1.3mm and 2.0mm, respectively. Inner bark thickness was 4.8mm in Q. acutissima and 3.6-3.9mm in the other oak species. The outer shape of ovipositional holes on the bark by the longicorn beetle was $8-12mm{\times}6-8mm$ wide oval in Q. variabilis, whereas $5-9mm{\times}1-5mm$ narrow fusiform in the other oak species. Oak longicorn beetle drilled average of three ovipositional holes per a 1.2m-long log in a few Q. variabilis logs and its ovipositional rate was 15%. Compared to this, the longicorn beetle preferred Q. mongolica. All the 32 investigated logs of this oak species were drilled to have 20 ovipositional holes per a log and ovipositional rate was 56%. One third of the eggs laid already hatched in early June to damage the inner bark. It seems that oak longicorn beetle prefers oak species with smooth, thin and stable outer bark surface.