bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does High Income Promote Democracy?
Authors: Londregan John B. , Poole Keith T. 
Published: February 2007

The authors construct a statistical model with which to test whether the regularity that democracy is more commonly found among wealthy countries stems from a democratizing effect of high income or is due entirely to other factors, such as the historical context, various features of the institutional setting, and simultaneity with the process of leadership change. Even after correcting for these many other influences, the democratizing effect of income remains as a statistically significant factor promoting the emergence of democratic political institutions. The authors go on to find that leaders' risks of losing power rise during their time in office and that these risks are higher in more democratic countries.The authors confirm the finding by Burkhart and Lewis-Beck that the democracy-promoting effect of income is stronger among the European countries. They suggest that high income has a more powerful democratizing effect among the Southern European countries because it interacts with pressure from major trading partners to democratize. This suggests a revaluation of policies designed to foster the replacement of authoritarian regimes by democratic ones through free trade.
The natural course of non-functioning pituitary macroadenomas
Authors: Dekkers O M , Hammer S , de Keizer R J W , Roelfsema F , Schutte P J , Smit J W A , Romijn J A , Pereira A M 
Published: February 2007

Objective: The natural history of non-functioning pituitary macroadenomas (NFMA) has not been completely elucidated. Therefore, we evaluated pituitary function, visual fields, and tumor size during long-term follow-up of non-operated patients with NFMA.
Design: Follow-up study.
Patients: Twenty-eight patients (age 55 ± 3 years) with NFMA, not operated after initial diagnosis, were included.
Results: Initial presentation was pituitary insufficiency in 44%, visual field defects in 14%, apoplexy in 14%, and chronic headache in 7% of the patients. The duration of follow-up was 85 ± 13 months. Radiological evidence of tumor growth was observed in 14 out of 28 patients (50%) after duration of follow-up of 118 ± 24 months. Six patients (21%) were operated, because tumor growth was accompanied by visual field defects. Visual impairments improved in all the cases after transsphenoidal surgery. Spontaneous reduction in tumor volume was observed in eight patients (29%). No independent predictors for increase or decrease in tumor volume could be found by regression analysis.
Conclusion: Observation alone is a safe alternative for transsphenoidal surgery in selected NFMA patients, without the risk of irreversibly compromising visual function.
Interaction of Plant Species Diversity on Grazing Behavior and Performance of Livestock Grazing Temperate Region Pastures
Authors: Soder K. J. , Rook A. J. , Sanderson M. A. , Goslee S. C. 
Published: February 2007

ABSTRACTThe importance of plant species diversity on performance of livestock grazing temperate region pastures is summarized in this review. As livestock producers seek less capital‐intensive production systems, emphasis is redirected toward low‐input pasture systems that rely on complex species mixtures to produce forage. Increased plant species diversity has been linked to improvements in ecosystem function. While it is recognized that grazing management can have a profound impact on sward composition, which in turn can affect grazing behavior and animal performance, the effects of increased plant species diversity on animal productivity (and vice versa) have not been well explored. This review addresses mechanisms by which grazing livestock alter cool‐season plant species diversity, mechanisms of diet choice, effects of plant species diversity on animal performance, and implications to sustainable domestic livestock grazing systems. We review evidence for these effects at one trophic level, that of grazing livestock in agroecosystems. While grazing behavior research conducted during the last several decades has led to advances in the understanding of plant–animal interactions, improved knowledge of these interactions is crucial for predicting animal performance. Also important is the evaluation of the impact of grazing livestock on mixed sward dynamics. This knowledge will lead to new opportunities to develop environmentally and economically sustainable grazing systems.
Nitrogn Use and Biomass Distribution in Culms of Winter Wheat Populations Selected from Grain‐Only and Dual‐Purpose Systems
Authors: MacKown Charles T. , Carver Brett F. 
Published: February 2007

ABSTRACTBeginning in late fall and ending at jointing in early spring, winter wheat (Triticum aestivum L.) crops in the southern Great Plains are often grazed by stocker cattle (Bos taurus L.) and then harvested for grain. Traditionally, dual‐purpose (grazing plus grain) wheat cultivars are developed from a grain‐only production system. Because culms of dual‐purpose grown wheat may forfeit productivity gains for grain‐only developed cultivars, we evaluated N and biomass traits at anthesis and maturity for 12 sets of subpopulations (each set a unique genetic background) to test benefits of making selections from a dual‐purpose system. Sets came from F2 sources and contained a “Base” F3 bulk population and F5 bulk populations mass selected from the F2 within grain‐only and dual‐purpose production systems. The 12 sets of subpopulations were evaluated in grain‐only and dual‐purpose production systems in 2001–2002 and 2002–2003. At anthesis, main effects (year, system, genetic background, subpopulation selection environment) were significant for culm dry weight and N, and flag leaf dry weight. Among selections, differences for these traits were small (2.0–3.5%) with no difference between grain‐only and dual‐purpose selections; differences among genetic backgrounds, however, were large (21–30%). At maturity, differences (7.6–20%) for grain dry weight and kernel mass, harvest index (HI), N content, grain N, and N harvest index (NHI) of individual culms occurred among genetic backgrounds. Differences among subpopulations were smaller (1.4–4.5%) and significant for only culm and grain dry weight, kernel number and mass, and culm N content. Selections made from the dual‐purpose environment performed similar to those from the grain‐only environment when grown in either production system.
Human cold adaptation: An unfinished agenda
Authors: Steegmann A. Theodore 
Published: February 2007

Abstract1975 marked the end of a 20‐year period of human biology research on physical environment. The focus then shifted from climatic adaptation to problems of nutrition, disease, and stress. However, many questions about human environmental patterns, especially in reference to their evolution, were abandoned rather than resolved. Assumptions about cold protective functions of low surface area/body mass ratio are entrenched in physical anthropology, despite lack of experimental validation. Since heat loss is controlled by vasoregulation and tissue insulation, a simple physics model of SA:mass may not apply. The issue merits investigation, as do the assumed thermal advantages of foreshortened extremities. Physiological assessment remains our primary research tool. In cold climate natives, elevated basal metabolic rates now appear to be genetically induced. During cold exposure, the body manages heat conservation through well known channels but also by specialized thermogenic functions such as metabolism in brown adipose tissue (BAT). The powerful protective capacity of BAT is largely unexplored either within or between populations of cold exposed human adults. An irony of our profession is that many biological variables seem to have minor effects when compared to behavioral cold protections. This is partly because biological anthropologists may have made incorrect assumptions about what most threatens the well being of cold climate people. Contrasts in environmental behaviors when comparing northern cultures such as Inuit, Athabaskan, and Norse are particularly instructive. Adaptations to life in the cold may ultimately reveal their secrets through biocultural research design modeling of environmental research. With both practical and theoretical gains still wide open, the field needs renewed attention from human biology. Am. J. Hum. Biol. 19:218–227, 2007. © 2007 Wiley‐Liss, Inc.
Are the circumpolar inuit becoming obese?
Authors: Young T.K. 
Published: February 2007

AbstractThis paper reviews the ethnographic, historical, and recent epidemiological evidence of obesity among the Inuit/Eskimo in the circumpolar region. The Inuit are clearly at higher risk for obesity than other populations globally, if “universal” measures based on body mass index (BMI) and waist circumference and criteria such as those of WHO are used. Inuit women in particular have very high mean waist circumference levels in international comparisons. Given the limited trend data, BMI‐defined obesity is more common today than even as recently as three decades ago. Inuit are not immune from the health hazards associated with obesity. However, the “dose–response” curves for the impact of obesity on metabolic indicators such as plasma lipids and blood pressure are lower than in other populations. Long‐term, follow‐up studies are needed to determine the metabolic consequences and disease risks of different categories of obesity. At least in one respect, the higher relative sitting height among Inuit, obesity measures based on BMI may not be appropriate for the Inuit. Ultimately, it is important to go beyond simple anthropometry to more accurate determination of body composition studies, and also localization of body fat using imaging techniques such as ultrasound and computed tomography. Internationally, there is increasing recognition of the need for ethnospecific obesity criteria. Notwithstanding the need for better quality epidemiological data, there is already an urgent need for action in the design and evaluation of community‐based health interventions, if the emerging epidemic of obesity and other chronic diseases are to be averted. Am. J. Hum. Biol. 19:181–189, 2007. © 2007 Wiley‐Liss, Inc.
Social contexts, syndemics, and infectious disease in northern Aboriginal populations
Authors: Ann Herring D. , Sattenspiel Lisa 
Published: February 2007

AbstractUntil the last half of the 20th century, infectious diseases dominated the health profile of northern North American Aboriginal communities. Research on the 1918 influenza pandemic exemplifies some of the ways in which the social context of European contact and ensuing economic developments affected the nature of infectious disease ecology as well as the frequency and severity of the problem. To understand these impacts it is necessary to consider the web of interactions among multiple pathogens, the biology of the human host, and the social environment in which people lived. At the very least, an understanding of the history of the impact of infectious diseases on northern North American communities requires attention not only to potential interactions among cocirculating pathogens, but their links to key social, historical, and economic factors that exacerbated their adverse effects and contributed to excess mortality. Am. J. Hum. Biol. 19:190–202, 2007. © 2007 Wiley‐Liss, Inc.
Adaptive dimensions of health research among indigenous Siberians
Authors: Snodgrass J. Josh , Sorensen Mark V. , Tarskaia Larissa A. , Leonard William R. 
Published: February 2007

AbstractPresent evidence suggests that modern humans were the first hominid species to successfully colonize high‐latitude environments (≥55°N). Given evidence for a recent (<200,000 years) lower latitude naissance of modern humans, the global dispersal and successful settlement of arctic and subarctic regions represent an unprecedented adaptive shift. This adaptive shift, which included cultural, behavioral, and biological dimensions, allowed human populations to cope with the myriad environmental stressors encountered in circumpolar regions. Although unique morphological and physiological adaptations among contemporary northern residents have been recognized for decades, human biologists are only now beginning to consider whether biological adaptations to regional environmental conditions influence health changes associated with economic modernization and lifestyle change. Recent studies have documented basal metabolic rates (BMRs) among indigenous Siberian populations that are systematically elevated compared to lower latitude groups; this metabolic elevation apparently is a physiological adaptation to cold stress experienced in the circumpolar environment. Important health implications of metabolic adaptation are suggested by research with the Yakut (Sakha), Evenki, and Buriat of Siberia. BMR is significantly positively correlated with blood pressure, independently of body size, body composition, and various potentially confounding variables (e.g., age and smoking). Further, this research has documented a significant negative association between BMR and LDL cholesterol, which remains after controlling for potential confounders; this suggests that high metabolic turnover among indigenous Siberians has a protective effect with regard to plasma lipid levels. These results underscore the importance of incorporating an evolutionary approach into health research among northern populations. Am. J. Hum. Biol. 19:165–180, 2007. © 2007 Wiley‐Liss, Inc.
Genetic structure of circumpolar populations: A synthesis
Authors: Crawford Michael H. 
Published: February 2007

AbstractThis article summarizes research conducted on the genetic structure of circumpolar populations of Alaska, Siberia, and the Aleutian Archipelago from 1977 to present. Three research programs are described: (1) 1977–1978, on the genetics of small, Yupik‐speaking communities of St. Lawrence Island (Savoonga and Gambell) compared with Inupk communities of King Island and Wales, Alaska. This research, based on 25 standard protein and blood markers, demonstrated genetic discontinuity between the populations of the two language groups, patterns of gene flow, and the co‐evolution of genes and languages in the Arctic. (2) 1989–1995, on the origins of Native American populations in Siberia. DNA was collected from two Evenki reindeer herding populations: Surinda and Poligus, a Ket community on the Stony Tunguska River, Sulamai, and a cattle‐herding village from Gorno Altai, Mendur‐Sokhon. Using an assortment of molecular markers, such as mitochondrial DNA, DNA fingerprints, and nonrecombining Y‐chromosome markers, this research demonstrated the close genetic affinities among the Siberian and the Native American indigenous groups. (3) 1999 to present, on the origins of populations of the Aleutian Islands and their underlying genetic structure. A total of 11 inhabited islands from the Aleutian Archipelago were sampled and based on mtDNA sequences was shown to cluster tightly with Siberian Eskimo and Chukchi populations. Evidence of genetic drift through founder effect was demonstrated on Bering Island, where the D2 haplotype was fixed. Genetic discontinuity based on mtDNA was shown through SAMOVA between Kamchatkan and Aleut populations. An intimate relationship between geography and genetics through Mantel tests was observed for both Siberia (r = 0.55 P > 0.001) and the Aleutian Islands (r = 0.72 P > 0.000). The genetic structure of the populations of the Aleutian Archipelago most closely approximates the isolation‐by‐distance model. Am. J. Hum. Biol. 19:203–217, 2007. © 2007 Wiley‐Liss, Inc.
Increasing knowledge of PTEN germline mutations: Two additional patients with autism and macrocephaly
Authors: Herman Gail E. , Butter Eric , Enrile Benedicta , Pastore Matthew , Prior Thomas W. , Sommer Annemarie 
Published: February 2007

AbstractRecently, Butler et al. [2005; J Med Genet 42:318–321] reported the presence of heterozygous germline mutations in the PTEN tumor suppressor gene in three children with autism and macrocephaly. Here, we report the presence of PTEN mutations in two additional unrelated children with macrocephaly and autism. Our findings extend those of Butler et al. and suggest that PTEN gene sequencing should be included in the genetic evaluation of this subset of autistic individuals. © 2007 Wiley‐Liss, Inc.
Entwicklung einer Toolbox zur zwei‐ und dreidimensionalen instationären thermischen Bauteilsimulation mit KARDOS
Authors: Erdmann Bodo , Ljubijankić Manuel , Nytsch‐Geusen Christoph 
Published: February 2007

AbstractZwei‐ und dreidimensionale dynamische thermische Bauteilsimulationen unter Berücksichtigung instationärer klimatischer Randbedingungen können das reale Bauteilverhalten in guter Näherung abbilden. Bisherige Werkzeuge zur mehrdimensionalen thermischen Bauteilsimulation weisen häufig Einschränkungen in den abzubildenden Bauteilgeometrien und ‐topologien auf oder können bzgl. zusätzlicher physikalischer Effekte (z. B. hygrothermisches Bauteilverhalten) nicht erweitert werden. Aus diesem Grund wurde auf Grundlage des allgemeinen FEM‐Werkzeugs KARDOS, mit welchem Multiphysics‐Probleme modelliert werden können, eine Toolbox zur thermischen Bauteilsimulation erstellt. Diese erlaubt die Eingabe nahezu beliebiger zwei‐ und dreidimensionaler Bauteilgeometrien in ein objektorientiertes Bauteilmodell. Ausgehend von diesem Bauteilmodell wird über einen Präprozessor die Vernetzung des Berechnungsgebiets für die FEM‐Simulation mit KARDOS automatisch durchgeführt. An Hand einiger Fallbeispiele wird die KARDOS‐basierte Toolbox zur Bauteilsimulation demonstriert.
Placental growth patterns affect birth weight for given placental weight
Authors: Salafia Carolyn M. , Zhang Jun , Miller Richard K. , Charles Adrian K. , Shrout Patrick , Sun Wenyu 
Published: February 2007

AbstractBACKGROUND:An important contributor to fetal growth is growth of the placenta, the fetus' sole source of nutrients and oxygen. Here we use placental growth measures (larger and smaller disk diameters, reflecting the laterally expanding chorionic plate, and disk thickness) to test the hypothesis that placental growth patterns, while associated with placental weight and birth weight, measure placental functional efficiency, and will have independent effects on the feto‐placental weight ratio (FPR).METHODS:Placental measures were available from 23,313 participants in the Collaborative Perinatal Project delivered between 34 and 43 completed weeks. Continuous variables were analyzed by regression for associations with placental weight, birth weight, and FPR, to further explore effects of placental growth patterns on the FPR (lateral chorionic plate growth and chorionic disk thickness were grouped as low, normal, and high values). The relationships of the nine resultant combinations of placental growth categories to the FPR using birth weight adjusted for gestational age, infant gender, parity, and African American race were analyzed (ANOVA).RESULTS:As chorionic disk area and thickness increased, birth weight and placental weight increased, and the FPR decreased (each p < .0001) after adjustment for gestational age, parity, race, and infant gender. Small, thin placental disks had an adjusted FPR of 8.46; the largest, thickest placentas had an adjusted FPR of 6.33. The nine categories of FPRs were significantly different, consistent with chorionic plate area and disk thickness combining to determine the FPR.CONCLUSIONS:Patterns of placental growth, relating to different functional dimensions of the placenta, deliver a different birth weight for a given placental weight. Birth Defects Research (Part A) 2007. © 2007 Wiley‐Liss, Inc.
Bioluminescent signal system: bioluminescence immunoassay of pathogenic organisms
Authors: Frank L. , Markova S. , Remmel N. , Vysotski E. , Gitelson I. 
Published: February 2007

AbstractThe Ca2+‐regulated photoprotein obelin has been examined as a label for bioluminescence immunoassay of infective agents. The hepatitis B virus (HbsAg) and the bacteria Escherichia coli and Shigella sonnei lipopolysaccharide (LPS) were chosen as model antigens. Chemically synthesized obelin‐corresponding antibody conjugates were used in a solid‐phase microplate immunoassay. The sensitivities achieved by the assay were 0.25 ng/mL for S. sonnei LPS and 0.375 ng/mL for HbsAg. A novel, filter‐based immunoassay to determine bacterial admixtures in the environment was proposed. The NanoCeram filters were effectively applied to ‘trap’ and pre‐concentrate pathogens from samples under study for the purposes of further detection and measurement of the absorbed material by bioluminescence immunoassay. Copyright © 2007 John Wiley & Sons, Ltd.
Bovine fetal microchimerism in normal and embryo transfer pregnancies and its implications for biotechnology applications in cattle
Authors: Turin Lauretta , Invernizzi Pietro , Woodcock Marion , Grati Francesca R. , Riva Federica , Tribbioli Giulia , Laible Götz 
Published: February 2007

AbstractFetal cells and DNA have been detected in the maternal circulation during and after pregnancy in a few mammalian species. The incidence of similar microchimerism in cattle could have repercussion for the application of modern biotechnologies such as the transfer of transgenic embryos. To determine if feto‐maternal leakage can occur in pregnant cows, we have analyzed maternal blood samples for the presence of fetal DNA during gestation and post‐partum periods. Y chromosome‐specific DNA was detected in up to 73% of blood samples from naturally mated heifers carrying conventional bull calves and a transgene‐specific sequence in up to 50% of recipient cows carrying transgenic fetuses. These findings document for the first time that transplacental leakage of fetal DNA into the maternal circulation can occur in cattle despite the epitheliochorial placenta of ruminants, with potential implications for the utilization of recipient cows in the food chain.
An artificial liver sinusoid with a microfluidic endothelial‐like barrier for primary hepatocyte culture
Authors: Lee Philip J. , Hung Paul J. , Lee Luke P. 
Published: February 2007

AbstractPrimary hepatocytes represent a physiologically relevant model for drug toxicity screening. Here, we created a biologically inspired artificial liver sinusoid with a microfluidic endothelial‐like barrier having mass transport properties similar to the liver acinus. This unit consisted of a cord of hepatocytes (50 × 30 × 500 µm) fed by diffusion of nutrients across the microfluidic endothelial‐like barrier from a convective transport vessel (10 nL/min). This configuration sustained rat and human hepatocytes for 7 days without an extracellular matrix (ECM) coating. Experiments with the metabolism mediated liver toxicant diclofenac showed no hepatotoxicity after 4 h and an IC50of 334 ± 41 µM after 24 h. Biotechnol. Bioeng. 2007; 97: 1340–1346. © 2007 Wiley Periodicals, Inc.