首页
登录
职称英语
The koala, one of Australia’s most treasured creatures, is in trouble? In Qu
The koala, one of Australia’s most treasured creatures, is in trouble? In Qu
游客
2023-12-23
7
管理
问题
The koala, one of Australia’s most treasured creatures, is in trouble? In Queensland, the vast state in Australia’s northeastern corner, surveys suggest that from 2001 to 2008, their numbers dropped as much as 45 percent in urban areas and 15 percent in bush land.
While climate change and habitat loss are affecting koalas and many other Australian animals— from birds and frogs to marsupials like wombats—it is a bacterial infection that is worrying many scientists about the fate of the koala. "Disease is a somewhat silent killer and has the very real potential to finish koala populations in Queensland," said Dr. Amber Gillett, a veterinarian at the Australia Zoo Wildlife Hospital in Beerwah.
The killer is chlamydia, a class of bacteria far better known for causing venereal disease in humans. Recent surveys show that chlamydia has caused symptoms in up to 50 percent of Queensland’s wild koalas, with more probably infected but not showing symptoms. The bacteria— transmitted during birth, through mating and possibly through fighting—come in two strains, neither the same as the human form. One form can jump to other species, but so far there is no evidence that it has spread from koalas to humans or vice versa.
Chlamydia causes a host of symptoms, including eye infections that can lead to blindness, respiratory infections and cysts? The epidemic has been severe in Queensland, where most koalas are infected with koala retrovirus, said Dr. Gillett. This retrovirus is an H. I. V. -like infection that suppresses the immune system and interferes with its ability to fight off chlamydia.
Treating chlamydia in wild koalas is a challenge. Only a small percentage of the animals can be treated successfully and returned to the wild. And infected females often become infertile, so future population growth is affected as well. There is no treatment available for koala retrovirus, but researchers are working to test a vaccine that would help prevent further spreading of chlamydia.
A study published in 2010 in The American Journal of Reproductive Immunology found that this vaccine is safe and effective in healthy female koalas. Further work is being done to test it in koalas that are already infected. Peter Timms, a professor at the Queensland University of Technology who is leading the effort to test the chlamydia vaccine, is hopeful that there will be another trial this year to test it in captive male koalas, followed by wild koalas. If all goes well, plans can be set in motion to distribute the vaccine.
Many experts believe this vaccine would be an important step in helping koalas survive longer, perhaps buying enough time for researchers to solve some of the other problems they face. "In situations where you combine habitat pressure, domestic dog attacks and car hits with severe chlamydial disease, the outcome for koalas is devastating," Dr. Gillett said. [br] According to the passage, the top killer that threatens koala populations in Queensland seems to be______.
选项
A、climate change
B、habitat loss
C、dog attack
D、infectious bacteria
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3297339.html
相关试题推荐
WhydoconservationistsinAustraliasupportthepolicyofkillingcats?[br][
WhydoconservationistsinAustraliasupportthepolicyofkillingcats?[br][
WhydoconservationistsinAustraliasupportthepolicyofkillingcats?[br][
WhydoconservationistsinAustraliasupportthepolicyofkillingcats?[origin
TheUniversityintransformation,editedbyAustralianfuturistsSohailInaya
TheUniversityintransformation,editedbyAustralianfuturistsSohailInaya
[originaltext]TherearethreelevelsofgovernmentinAustralia:firstly,th
[originaltext]W:Derek,howisyourkneetoday?Isitstillgivingyoutrouble?
[originaltext]Australiaisalmostacontinentbyitself.Thevastnessofth
[originaltext]Australiaisalmostacontinentbyitself.Thevastnessofth
随机试题
[originaltext]TheresultsofthemunicipalelectionsinItalyinwhichthe
AustraliahasbeenunusualintheWesternworldinhavingavery【C1】______at
LinguisticFolliesAInrecentyearsBrusselshasbeen
下列地质地貌在地震条件下哪个地段不属于危险地段?()A.泥石流地段 B.液
劳务培训的内容要注重()三者的兼顾。A.知识、技能、态度 B.学历、技能、态
(2017年真题)单家商业银行对单一金融机构法人的不含结算性同业存款的同业融出资
2011年,深圳市进出口总额为()亿美元。A.4877.41 B.
药物剂型按照分散系统分类,涂膜剂属于A:真溶液类B:胶体溶液类C:乳浊液类
火灾探测器波纹管应使用(____)材质。(A)不锈钢(B)金属(C)铜合
A.虫蛀 B.霉变 C.挥发 D.沉淀 E.酸败片剂在贮藏中易
最新回复
(
0
)