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Keith Cheng

Publications and source records attributed to Keith Cheng.

4 recordsLinked to original sources
PubMed2006

Genetic evidence for the convergent evolution of light skin in Europeans and East Asians.

Human skin pigmentation shows a strong positive correlation with ultraviolet radiation intensity, suggesting that variation in skin color is, at least partially, due to adaptation via natural selection. We investigated the evolution of pigmentation variation by testing for the presence of positive directional selection in 6 pigmentation genes using an empirical F(ST) approach, through an examination of global diversity patterns of these genes in the Centre d'Etude du Polymorphisme Humain (CEPH)-Diversity Panel, and by exploring signatures of selection in data from the International HapMap project. Additionally, we demonstrated a role for MATP in determining normal skin pigmentation variation using admixture mapping methods. Taken together (with the results of previous admixture mapping studies), these results point to the importance of several genes in shaping the pigmentation phenotype and a complex evolutionary history involving strong selection. Polymorphisms in 2 genes, ASIP and OCA2, may play a shared role in shaping light and dark pigmentation across the globe, whereas SLC24A5, MATP, and TYR have a predominant role in the evolution of light skin in Europeans but not in East Asians. These findings support a case for the recent convergent evolution of a lighter pigmentation phenotype in Europeans and East Asians.

Black or African American↗
PubMed2006

Integrating evidence-based practice in the child mental health agency: a template for clinical and organizational change.

This article describes a linked set of activities designed to address the present "science-to-service" gap in evidence-based practice from the perspective of the nonprofit child mental health agency: (a) implementing "systems-of-care" principles; (b) logic modeling; (c) strategic partnerships with external researchers; (d) selective, in-depth program evaluation; (e) critical comparison with a limited number of evidence-based practice models of national significance; and (f) internal and external dissemination activities oriented to evidence-based practice. Implications are drawn both for continuous quality improvement of existing clinical services and for the potential for agencies to contribute high quality, science-based information to child mental health services, singly and through the future development of a national network of experimenting child mental health agencies.

Child↗
PubMed2006

Traumatized refugee children: the case for individualized diagnosis and treatment.

The first 131 traumatized refugee children evaluated and treated in a child specialty clinic indicated a wide variety of trauma including war-related traumas (21%) for areas of recent conflict and domestic violence (28%) predominantly occurring in patients from Mexico and Latin America. Clinical diagnoses indicate PTSD was common (63%) in the war trauma group but was found less (25%) in the domestic violence group. Otherwise, the refugee clinic population showed a wide variety of diagnoses, including 20% having learning or cognitive disability or clear mental retardation. The traumatized refugee children had a similar prevalence of PTSD and depression to a comparable group of American child psychiatry patients. Refugee children have faced a variety of traumas and have a variety of diagnoses. All traumatized refugee children need an individualized evaluation and treatment plan. Trauma focused therapy is not appropriate for all refugee children.

Child↗