Going the distance: human population genetics in a clinal world.

Global human genetic variation is greatly influenced by geography, with genetic differentiation between populations increasing with geographic distance and within-population diversity decreasing with distance from Africa. In fact, these 'clines' can explain most of the variation in human populations. Despite this, population genetics inferences often rely on models that do not take geography into account, which could result in misleading conclusions when working at global geographic scales. Geographically explicit approaches have great potential for the study of human population genetics. Here, we discuss the most promising avenues of research in the context of human settlement history and the detection of genomic elements under natural selection. We also review recent technical advances and address the challenges of integrating geography and genetics.

Building World-Class Schools for Iowa: A Legislative Brief, January 14, 2013

The Iowa Department of Education has joined the Office of the Governor to prepare a set of legislative proposals that will bring Iowa closer to its goal of providing a world-class education to all children, no mater where they live. This legislative brief serves as an overview of the legislation, which I encourage you to read and discuss in greater detail. the goals behind these policies are straightforward: Comprehensive and systematically raise and support the teaching profession while expanding efforts to customize instruction to every student's passion and talents. Iowa's children deserve the best education can provide so they leave our schools with the knowledge and skills necessary for successful and rewarding lives. Iowa has many good schools with hard-working, talented educators who deserves our respect and appreciation. While we honor the past work of generations of Iowans who built a strong foundation, it is our responsibility - and our turn - to make a focused, dedicated effort to improve Iowa's schools. We stand at a pivotal moment in Iowa storied education history, in which we have the opportunity and will as community to make the transition from being "good" to being "great".

Locations of new industry, 1971-1980.

Map of railroads and locations of new industries in Iowa, 1971-1980

Representational pseudoneglect and reference points both influence geographic location estimates

Our mental representation of the world is far from objective. For example, western Canadians estimate the locations of North American cities to be too far to the west. This bias could be due to a reference point effect, in which people estimate more space between places close to them than far from them, or to representational pseudoneglect, in which neurologically intact individuals favor the left side of space when asked to image a scene.We tested whether either or both of these biases influence the geographic world representations of neurologically intact young adults from Edmonton and Ottawa, which are in western and eastern Canada, respectively. Individuals were asked to locate NorthAmerican cities on a two-dimensional grid. Both groups revealed effects of representational pseudoneglect in this novel paradigm, but they also each exhibited reference point effects. These results inform theories in both cognitive psychology and neuroscience.

Díaz-Andreu, Margarita: A world history of nineteenth century archaeology. Nationalism, Colonialism, and the Past.

M. Díaz-Andreu plantea un análisis de las implicaciones académicas, sociales y políticas de la arqueología (entendiendo como tal la investigación estricta, pero también el coleccionismo de obras de arte) entre finales del siglo XVIII y el inicio de la Primera Guerra Mundial, período durante el cual la formación y expansión de los imperios coloniales constituyó uno de los elementos clave en el discurso ideológico de los estados europeos. Su trabajo continúa la línea marcada por estudios suyos anteriores, esencialmente Nationalism and Archaeology in Europe (Díaz-Andreu & T. Champion [eds.], 1996) y Excavating Women. A History in European Archaeology (Díaz-Andreu & M. L. S. Sorensen, 1998), en los que combinaba el análisis historiográfico de diferentes aspectos y personajes clave de la arqueología europea desde la perspectiva de la organización de las redes sociales entre investigadores, con la reflexión sobre las implicaciones de la arqueología como ciencia en la definición y defensa de diferentes credos políticos, y el papel de la mujer en la investigación.

Receptor binding and cell entry of Old World arenaviruses reveal novel aspects of virus-host interaction.

Ten years ago, the first cellular receptor for the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) and the highly pathogenic Lassa virus (LASV) was identified as alpha-dystroglycan (alpha-DG), a versatile receptor for proteins of the extracellular matrix (ECM). Biochemical analysis of the interaction of alpha-DG with arenaviruses and ECM proteins revealed a strikingly similar mechanism of receptor recognition that critically depends on specific sugar modification on alpha-DG involving a novel class of putative glycosyltransferase, the LARGE proteins. Interestingly, recent genome-wide detection and characterization of positive selection in human populations revealed evidence for positive selection of a locus within the LARGE gene in populations from Western Africa, where LASV is endemic. While most enveloped viruses that enter the host cell in a pH-dependent manner use clathrin-mediated endocytosis, recent studies revealed that the Old World arenaviruses LCMV and LASV enter the host cell predominantly via a novel and unusual endocytotic pathway independent of clathrin, caveolin, dynamin, and actin. Upon internalization, the virus is rapidly delivered to endosomes via an unusual route of vesicular trafficking that is largely independent of the small GTPases Rab5 and Rab7. Since infection of cells with LCMV and LASV depends on DG, this unusual endocytotic pathway could be related to normal cellular trafficking of the DG complex. Alternatively, engagement of arenavirus particles may target DG for an endocytotic pathway not normally used in uninfected cells thereby inducing an entry route specifically tailored to the pathogen's needs.

A comparison of the performance of modern screen-film and digital mammography systems.

This work compares the detector performance and image quality of the new Kodak Min-R EV mammography screen-film system with the Fuji CR Profect detector and with other current mammography screen-film systems from Agfa, Fuji and Kodak. Basic image quality parameters (MTF, NPS, NEQ and DQE) were evaluated for a 28 kV Mo/Mo (HVL = 0.646 mm Al) beam using different mAs exposure settings. Compared with other screen-film systems, the new Kodak Min-R EV detector has the highest contrast and a low intrinsic noise level, giving better NEQ and DQE results, especially at high optical density. Thus, the properties of the new mammography film approach those of a fine mammography detector, especially at low frequency range. Screen-film systems provide the best resolution. The presampling MTF of the digital detector has a value of 15% at the Nyquist frequency and, due to the spread size of the laser beam, the use of a smaller pixel size would not permit a significant improvement of the detector resolution. The dual collection reading technology increases significantly the low frequency DQE of the Fuji CR system that can at present compete with the most efficient mammography screen-film systems.

Working in a digital world: new leadership practices for the development of a digital library workforce

Digital library developments are part of a global move in many sectors of society toward virtual work and electronic services made possible by the advances in information technology. This environment requires new attitudes and skills in the workforce and therefore leaders who understand the global changes underlying the new information economy and how to lead and develop such a workforce. This article explores ways to develop human resources and stimulate creativity to capitalize on the immense potential of digital libraries to educate and empower social change. There is a shortage of technically skilled workers and even more so of innovators. Retention and recruitment is one of the greatest obstacles to developing digital library services and information products.

Alterations in Postural Control during the World's Most Challenging Mountain Ultra-Marathon

We investigated postural control (PC) effects of a mountain ultra-marathon (MUM): a 330-km trail run with 24000 m of positive and negative change in elevation. PC was assessed prior to (PRE), during (MID) and after (POST) the MUM in experienced ultra-marathon runners (n = 18; finish time = 126+/-16 h) and in a control group (n = 8) with a similar level of sleep deprivation. Subjects were instructed to stand upright on a posturographic platform over a period of 51.2 seconds using a double-leg stance under two test conditions: eyes open (EO) and eyes closed (EC). Traditional measures of postural stability (center of pressure trajectory analysis) and stabilogram-diffusion analysis (SDA) parameters were analysed. For the SDA, a significantly greater short-term effective diffusion was found at POST compared with PRE in the medio-lateral (ML; Dxs) and antero-posterior (AP) directions (Dys) in runners (p<0.05) The critical time interval (Ctx) in the ML direction was significantly higher at MID (p<0.001) and POST (p<0.05) than at PRE in runners. At MID (p<0.001) and POST (p<0.05), there was a significant difference between the two groups. The critical displacement (Cdx) in the ML was significantly higher at MID and at POST (p<0.001) compared with PRE for runners. A significant difference in Cdx was observed between groups in EO at MID (p<0.05) and POST (p<0.005) in the ML direction and in EC at POST in the ML and AP directions (p<0.05). Our findings revealed significant effects of fatigue on PC in runners, including, a significant increase in Ctx (critical time in ML plan) in EO and EC conditions. Thus, runners take longer to stabilise their body at POST than at MID. It is likely that the mountainous characteristics of MUM (unstable ground, primarily uphill/downhill running, and altitude) increase this fatigue, leading to difficulty in maintaining balance.