Populations in Southern China (Bai-yue) and Borneo (Bidayuh) with high incidence of nasopharyngeal cancer(NPC) share similar mitochondrial DNA signatures, supporting the hypothesis that these two populations may share the same genetic predisposition for NPC, which may have first appeared in a common ancestral reference population before the sea levels rose after the last ice age.
Borneo ; epidemiology ; Carcinoma ; China ; epidemiology ; DNA, Mitochondrial ; genetics ; Ethnic Groups ; genetics ; Genetic Predisposition to Disease ; Humans ; Incidence ; Nasopharyngeal Neoplasms ; epidemiology ; ethnology ; genetics

INTRODUCTIONThe journal impact factor is often used to judge the scientific quality of individual research articles and individual journals. Despite numerous reviews in the literature criticising such use, in some countries the impact factor has become an outcome measure for grant applications, job applications, promotions and bonuses. The aim of this review is to highlight the major issues involved with using the journal impact factor as a measure of research quality.

METHODSA literature review of articles on journal impact factors, science citation index, and bibliometric methods was undertaken to identify relevant articles.

RESULTSThe journal impact factor is a quantitative measure based on the ratio between yearly citations in a particular journal to total citations in that journal in the previous 2 years. Its use as a criterion for measuring the quality of research is biased. The major sources of bias include database problems from the Institute for Scientific Information and research field effects. The journal impact factor, originally designed for purposes other than the individual evaluation of research quality, is a useful tool provided its interpretation is not extrapolated beyond its limits of validity.

CONCLUSIONResearch quality cannot be measured solely using the journal impact factor. The journal impact factor should be used with caution, and should not be the dominant or only factor determining research quality.

Authorship ; Bias ; Bibliometrics ; Humans ; Peer Review, Research ; Periodicals as Topic ; statistics & numerical data ; Publishing ; statistics & numerical data ; Research Support as Topic

Nasopharyngeal cancer (NPC) is endemic in Southern China, with Guandong province and Hong Kong reporting some of the highest incidences in the world. The journal Science has called it a "Cantonese cancer". We propose that in fact NPC is a cancer that originated in the Bai Yue ("proto Tai Kadai" or "proto Austronesian" or "proto Zhuang") peoples and was transmitted to the Han Chinese in southern China through intermarriage. However, the work by John Ho raised the profile of NPC, and because of the high incidence of NPC in Hong Kong and Guangzhou, NPC became known as a Cantonese cancer. We searched historical articles, articles cited in PubMed, Google, monographs, books and Internet articles relating to genetics of the peoples with high populations of NPC. The migration history of these various peoples was extensively researched, and where possible, their genetic fingerprint identified to corroborate with historical accounts. Genetic and anthropological evidence suggest there are a lot of similarities between the Bai Yue and the aboriginal peoples of Borneo and Northeast India; between Inuit of Greenland, Austronesian Mayalo Polynesians of Southeast Asia and Polynesians of Oceania, suggesting some common ancestry. Genetic studies also suggest the present Cantonese, Minnans and Hakkas are probably an admixture of northern Han and southern Bai Yue. All these populations have a high incidence of NPC. Very early contact between southern Chinese and peoples of East Africa and Arabia can also account for the intermediate incidence of NPC in these regions.
Asia, Southeastern ; epidemiology ; Asian Continental Ancestry Group ; genetics ; history ; Borneo ; epidemiology ; China ; epidemiology ; Emigration and Immigration ; history ; Ethnic Groups ; genetics ; history ; Female ; Genetic Predisposition to Disease ; epidemiology ; ethnology ; genetics ; Genetics, Population ; Greenland ; epidemiology ; History, Ancient ; Hong Kong ; epidemiology ; Humans ; Incidence ; India ; epidemiology ; Inuits ; genetics ; Male ; Nasopharyngeal Neoplasms ; epidemiology ; ethnology ; genetics ; mortality ; Oceania ; epidemiology