102年 - 102 國立嘉義大學_農業科學博士學位學程招生考試試題：農學專業英文#146489

I.
　Climate change is a significant and lasting change in thestatistical distribution of weather patterns over periods rangingfrom decades to millions of years. It may be a change in averageweather conditions, or in the distribution of weather around theaverage conditions (i.e., more or fewer extreme weather events).Climate change is caused by factors that include oceanic processes(such as oceanic circulation ), biotic processes, variations in solar radiation received by Earth, plate tectonics and volcanic eruptions ,and human-induced alterations of the natural world; these lattereffects are currently causing global warming , and "climate change"is often used to describe human-specific impacts.

II.
Forest ecosystems are important components of the globalcarbon cycle in at least two ways. First, terrestrial ecosystemsremove nearly 3 billion tons of anthropogenic carbon every year (3Pg C year–1) through net growth, absorbing about 30% of allCO2 emissions from fossil fuel burning and net deforestation.Forests are major contributors to this terrestrial carbon sink andits associated economic benefits. Second, 4 billion hectares offorest ecosystems (4 × 103 Mha; about 30% of the global landarea) store large reservoirs of carbon, together holding more thandouble the amount of carbon in the atmosphere. Although theclimate protection role of forests is in no doubt, it is complex todetermine how much of the forest carbon sink and reservoir can bemanaged to mitigate atmospheric CO2 buildup, and in what way.

III.
(1)
　In cutting-tool design, a compromise must often be made. Itwould seem advantageous to increase the cutting angle and reduce the sharpness angle, thereby reducing the amount of distortion ofthe chip and the resulting forces against the tool. In practice,however, one soon runs up against the limitations of steel. Such anidealized cutting edge would have little strength, and would soonbreak or become dull. Increasing the sharpness angle of the toolmakes the edge more durable, but eventually leads to excessivefrictional resistance or to uncontrollable chip formation.

(2)
　The mortise and tenon—Fastening of end-grain to side-grainjoints can be accomplished with a high level of success using themortise and tenon. The basic joint is fashioned by forming the end-grain component, the tenon, into a round or rectangular crosssection and inserting it into a hole, or mortise, of the same size andshape in the side-grain component.

IV.
　Biosecurity is specific operational steps to stop diseases fromentering your farm or once animals are infected, stopping it fromspreading to other barns on the farm or to other farms. Biosecurityis important for a great number of reasons. First, it is an essentialaspect of on farm food safety programs. Keeping food productswholesome and of highest quality is important for the health andwelfare of consumers. Secondly, animals are healthier and moreproductive. This benefits the farming community through greaterefficiency and profitability. Finally, a vibrant agriculturalcommunity is a positive influence on the economy of our nation,and an important resource in maintaining a healthy environment.

V.
　Escherichia coli Vacuolating Factor (ECVF) is a heat-labile,vacuolating cytotoxin produced by avian pathogenic E. coli (APEC)isolated from avian cellulitis lesions. In this report, we intend todemonstrate that purified ECVF induces the inflammatory processof cellulitis. Our group is the first to demonstrate the effect ofECVF in a histological analysis by in situ inoculation of broilerchickens with purified ECVF. The animals were inoculated with theAPEC AC53 and with purified ECVF subcutaneously on theirventral surface (in the sternum region). The histological analysisshowed different grades of an acute inflammatory response in theepidermis, dermis and panniculus. An increase in mRNAexpression of the proinflammatory cytokine TNF-a was also demonstrated in the inflamed tissue. When ECVF was systemicallyadministered, increased levels of TNF-a and IL-10 were observedin the serum. These results suggest that ECVF plays a key role inthe inflammatory process associated with cellulitis that is mainlymediated by TNF-a. In addition, this inflammation can bedownregulated by the anti-inflammatory cytokine IL-10.