http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Hoekstra, Rutger (검색결과 5 건)
-
-
-
Hoekstra, Jonathan M University of Washington 2001 해외박사(DDOD)
Understanding ecological and evolutionary consequences of variation in habitat quality is increasingly important as biologists seek to address human-mediated environmental change. I investigated effects of natural temperature variation on individual fitness and population dynamics of <italic>Drosophila melanogaster </italic> inhabiting rotting apples in orchards. I also examined how critical habitat designations have influenced recovery plans for threatened and endangered species. I exposed <italic>D. melanogaster</italic> to field temperatures in rotting apples and measured survivorship and development time. Extreme temperatures in sun-exposed apples reduced survivorship of <italic>D. melanogaster</italic> by more than 50% relative to that in shaded apples. This difference is comparable to that caused by seasonal changes in ambient temperature, and suggested that selection will target traits conferring greater heat resistance. I next conducted a 3 x 2 factorial experiment that revealed an interaction effect of ethanol and temperature variation between shaded and sun-exposed apples on development time. Adverse effects of high ethanol concentrations and extreme temperatures in sun-exposed apples mitigated one another. Expected correlation between selection for ethanol and heat resistance depends on whether this result derived from cross-induction of physiological stress responses or abiotic interactions between temperature and ethanol. To test an hypothesis that habitat heterogeneity reduces climate-induced population variability, I established populations of <italic>D. melanogaster </italic> during summer and autumn in large field cages that enclosed “landscapes” of rotting apples. I manipulated habitat heterogeneity with shade cloth to create homogeneous landscapes of either shaded or sun-exposed apples, and heterogeneous landscapes with both. Population density and growth rate varied less between summer and autumn in heterogeneous cages than in either homogeneous treatment. These results suggested that managing for habitat heterogeneity may reduce population variability and thus mitigate risks of stochastic extinction. Lastly, I examined how critical habitat designations influenced recovery plans for threatened and endangered species. Plans for species with critical habitat were not more likely than others to prescribe habitat-based recovery actions or habitat-based recovery criteria. Findings suggested that recovery plans for endangered species have not benefited from critical habitat designations and raised questions about how policies might be amended so that future recovery plans will benefit.
-
Resonance Raman and Time Dependent Theory Studies of Ground and Excited State Mixed Valence
Hoekstra, Ryan Matthew University of California, Los Angeles 2010 해외박사(DDOD)
The work covered in this thesis focuses on application and development of mixed valence theory, which is described in chapter 1. Mixed Valence molecules have two or more equivalent charge bearing units which interact with each other through a bridge. The interaction provides an interesting problem of curved crossed potentials, which show different behavior depending on the strength of interaction. The second chapter provides an example of a simple molecule with a strong interaction between the charge bearing units, which is the simplest mixed valence scenario. In the final chapter a mixed valence system whose interaction is tunable by solvent is observed. This system was tuned to a very weak interaction such that the curve crossed potential dominates the spectral signal observed. The mixed valence theory formalism is also extended from only two charge bearing units to allow for three charge bearing units. The specific details of the mixed valence theory can be understood by the employment of time-dependent theory of molecular spectroscopy. In addition to its use in understanding the trends of mixed valence theory it can also be used to understand how the normal coordinates are affected by photoexcitation by calculating the resonance Raman and electronic spectra observed for each molecule.
-
Hoekstra, Erin ProQuest Dissertations & Theses University of Minn 2019 해외박사(DDOD)
Bridging critical health and migration studies, this dissertation examines the health effects of racialized processes of immigrant criminalization, focusing on the organizations that provide medical care in an informal, often underground, health system. Governed by a “biopolitics of disposability” (Giroux 2006), immigrant ineligibility for health care contributes to undocumented migrants’ experience as distinctly vulnerable, exploitable, and ultimately disposable. Whereas health institutions are usually figured as solutions to the violence embodied in unequal health outcomes, this dissertation argues that spaces of health are also perpetrators of structural violence. Clinics operate as de facto border checkpoints, leaving migrant patients susceptible to deportation for accessing emergency medical services. In the face of the violence of the mainstream health system, a network of humanitarian organizations provide health care to uninsured, undocumented migrants, while resisting the collusion between health and immigration enforcement. In contrast to medical humanitarianism’s focus on constructions of migrant “deservingness,” this dissertation argues that the concept of biocitizenship, a medicalized belonging based on common humanity, transcends dichotomies of deserving and undeserving, “good” or “bad” migrants. Biocitizenship also critiques the disentitlement and dehumanization of a biopolitics of disposability. Drawing from twelve months of ethnographic fieldwork with free clinics and humanitarian organizations across Arizona, this dissertation examines immigrant health justice (IHJ) organizations’ use of humanitarianism as both a discursive strategy and a field of action. In the borderlands, IHJ organizations frame their politically-contentious work as apolitical medical care and fight for the recognition of the patient status of migrants in need of emergency first aid. In the interior, the IHJ turns its critique toward “health” itself. Employing a rights-based humanitarian discourse, activists castigate the for-profit health system as complicit with immigration enforcement, indicting it for mass structural violence. Centrally, this dissertation argues that these related but distinct discourses across the borderlands and interior amount to an insurgent humanitarianism that exposes the fatal consequences of immigrant criminalization. By claiming various biocitizenships on behalf of their patients, IHJ organizations and activists use medicalized language as the basis of a politics of visibility, highlighting the health needs and fatalities of migrants across the country.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
