Measurement of genetic structure within populations using Moran's spatial autocorrelation statistics.

Spatial structure of genetic variation within populations, an important interacting influence on evolutionary and ecological processes, can be analyzed in detail by using spatial autocorrelation statistics. This paper characterizes the statistical properties of spatial autocorrelation statistics in this context and develops estimators of gene dispersal based on data on standing patterns of genetic variation. Large numbers of Monte Carlo simulations and a wide variety of sampling strategies are utilized. The results show that spatial autocorrelation statistics are highly predictable and informative. Thus, strong hypothesis tests for neutral theory can be formulated. Most strikingly, robust estimators of gene dispersal can be obtained with practical sample sizes. Details about optimal sampling strategies are also described.

Two genes abrogate the inhibition of murine hepatocarcinogenesis by ovarian hormones.

Hormonal and genetic factors strongly influence the susceptibility of inbred mice to hepatocarcinogenesis. Female C57BR/cdJ (BR) mice are extremely susceptible to liver tumor induction relative to other strains because they are genetically insensitive to the inhibition of hepatocarcinogenesis by ovarian hormones. To determine the genetic basis for the sensitivity of BR mice relative to resistant C57BL/6J (B6) mice, we treated 12-day-old B6BRF1 x B6 and B6BRF1 x B6BRF1 (F2) animals with N,N-diethylnitrosamine (0.1 micromol/g of body weight) and enumerated liver tumors at 32 weeks of age in males and at 50 weeks in females. Genomic DNA samples from backcross and F2 mice were analyzed for 70 informative simple sequence length polymorphism markers. Genetic markers on chromosome 17 (D17Mit21) and chromosome 1 (D1Mit33) cosegregated with high tumor multiplicity in both sexes. Together, these loci [designated Hcf1 and Hcf2 (Hepatocarcinogenesis in females), respectively] account for virtually all of the difference in sensitivity between BR and B6 mice. The Hcf1 locus accounts for a majority of the higher susceptibility of BR mice of both sexes. Backcross female mice heterozygous at both loci (33 +/- 23 tumors per mouse) and at Hcf1 only (17 +/- 18) were 15- and 8-fold more sensitive, respectively, than mice homozygous for the B6 alleles at Hcf1 and Hcf2 (2.2 +/- 3.9). In backcross male mice, the double heterozygotes (35 +/- 22) and Hcf1 heterozygotes (28 +/- 12) were 5.4- and 4.3-fold more sensitive than mice homozygous for B6 alleles at both loci (6.5 +/- 5.4).

A rat genetic map constructed by representational difference analysis markers with suitability for large-scale typing.

Representational difference analysis (RDA) was applied to isolate chromosomal markers in the rat. Four series of RDA [restriction enzymes, BamHI and HindIII; subtraction of ACI/N (ACI) amplicon from BUF/Nac (BUF) amplicon and vice versa] yielded 131 polymorphic markers; 125 of these markers were mapped to all chromosomes except for chromosome X. This was done by using a mapping panel of 105 ACI x BUF F2 rats. To complement the relative paucity of chromosomal markers in the rat, genetically directed RDA, which allows isolation of polymorphic markers in the specific chromosomal region, was performed. By changing the F2 driver-DNA allele frequency around the region, four markers were isolated from the D1Ncc1 locus. Twenty-five of 27 RDA markers were informative regarding the dot blot analysis of amplicons, hybridizing only with tester amplicons. Dot blot analysis at a high density per unit of area made it possible to process a large number of samples. Quantitative trait loci can now be mapped in the rat genome by processing a large number of samples with RDA markers and then by isolating markers close to the loci of interest by genetically directed RDA.

Logarithm of odds (lods) for linkage in complex inheritance.

Lod scores provide a method to unify linkage tests based on identity by descent and identity in marker state while permitting selection of the most informative individuals through their disease-related phenotypes and markers in relatives. After parametric lods are reviewed, a nonparametric approach that depends on a single logistic parameter beta is introduced. Lods for parents tested or unknown are derived, multiple pairwise mapping is presented, and power is shown to be good even for moderately small values of beta. Comparison of parametric and nonparametric approaches (yet to be made) will provide for polygenes the efficiency and reliability that lod scores gave to mapping of major loci 40 years ago.

Transduction of pluripotent human hematopoietic stem cells demonstrated by clonal analysis after engraftment in immune-deficient mice.

Gene transduction of pluripotent human hematopoietic stem cells (HSCs) is necessary for successful gene therapy of genetic disorders involving hematolymphoid cells. Evidence for transduction of pluripotent HSCs can be deduced from the demonstration of a retroviral vector integrated into the same cellular chromosomal DNA site in myeloid and lymphoid cells descended from a common HSC precursor. CD34+ progenitors from human bone marrow and mobilized peripheral blood were transduced by retroviral vectors and used for long-term engraftment in immune-deficient (beige/nude/XIS) mice. Human lymphoid and myeloid populations were recovered from the marrow of the mice after 7-11 months, and individual human granulocyte-macrophage and T-cell clones were isolated and expanded ex vivo. Inverse PCR from the retroviral long terminal repeat into the flanking genomic DNA was performed on each sorted cell population. The recovered cellular DNA segments that flanked proviral integrants were sequenced to confirm identity. Three mice were found (of 24 informative mice) to contain human lymphoid and myeloid populations with identical proviral integration sites, confirming that pluripotent human HSCs had been transduced.

Polymorphic simple sequence repeat regions in chloroplast genomes: applications to the population genetics of pines.

Simple sequence repeats (SSRs), consisting of tandemly repeated multiple copies of mono-, di-, tri-, or tetranucleotide motifs, are ubiquitous in eukaryotic genomes and are frequently used as genetic markers, taking advantage of their length polymorphism. We have examined the polymorphism of such sequences in the chloroplast genomes of plants, by using a PCR-based assay. GenBank searches identified the presence of several (dA)n.(dT)n mononucleotide stretches in chloroplast genomes. A chloroplast (cp) SSR was identified in three pine species (Pinus contorta, Pinus sylvestris, and Pinus thunbergii) 312 bp upstream of the psbA gene. DNA amplification of this repeated region from 11 pine species identified nine length variants. The polymorphic amplified fragments were isolated and the DNA sequence was determined, confirming that the length polymorphism was caused by variation in the length of the repeated region. In the pines, the chloroplast genome is transmitted through pollen and this PCR assay may be used to monitor gene flow in this genus. Analysis of 305 individuals from seven populations of Pinus leucodermis Ant. revealed the presence of four variants with intrapopulational diversities ranging from 0.000 to 0.629 and an average of 0.320. Restriction fragment length polymorphism analysis of cpDNA on the same populations previously failed to detect any variation. Population subdivision based on cpSSR was higher (Gst = 0.22, where Gst is coefficient of gene differentiation) than that revealed in a previous isozyme study (Gst = 0.05). We anticipate that SSR loci within the chloroplast genome should provide a highly informative assay for the analysis of the genetic structure of plant populations.

Documentation of reticulate evolution in peonies (Paeonia) using internal transcribed spacer sequences of nuclear ribosomal DNA: implications for biogeography and concerted evolution.

The internal transcribed spacers (ITS) of nuclear ribosomal DNA of 33 species of genus Paeonia (Paeoniaceae) were sequenced. In section Paeonia, different patterns of nucleotide additivity were detected in 14 diploid and tetraploid species at sites that are variable in the other 12 species of the section, suggesting that reticulate evolution has occurred. Phylogenetic relationships of species that do not show additivity, and thus ostensibly were not derived through hybridization, were reconstructed by parsimony analysis. The taxa presumably derived through reticulate evolution were then added to the phylogenetic tree according to additivity from putative parents. The study provides an example of successfully using ITS sequences to reconstruct reticulate evolution in plants and further demonstrates that the sequence data could be highly informative and accurate for detecting hybridization. Maintenance of parental sequences in the species of hybrid origin is likely due to slowing of concerted evolution caused by the long generation time of peonies. The partial and uneven homogenization of parental sequences displayed in nine species of putative hybrid origin may have resulted from gradients of gene conversion. The documented hybridizations may have occurred since the Pleistocene glaciations. The species of hybrid origin and their putative parents are now distantly allopatric. Reconstruction of reticulate evolution with sequence data, therefore, provides gene records for distributional histories of some of the parental species.

Library and Information Science Education and eScience: The Current State of ALA Accredited MLS/MLIS Programs in preparing Librarians and Information Professionals for eScience Needs

The purpose of this study is multifaceted: 1) to describe eScience research in acomprehensive way; 2) to help library and information specialists understand the realm of eScience research and the information needs of the community and demonstrate the importance of LIS professionals within the eScience domain; 3) and to explore the current state of curricular content of ALA accredited MLS/MLIS programs to understand the extent to which they prepare new professionals within eScience librarianship. The literature review focuses heavily on eScientists and other data-driven researchers’ information service needs in addition to demonstrating how and why librarians and information specialists can and should fulfill these service gaps and information needs within eScience research. By looking at the current curriculum of American Library Association (ALA) accredited MLS/MLIS programs, we can identify potential gaps in knowledge and where to improve in order to prepare and train new MLS/MLIS graduates to fulfill the needs of eScientists. This investigation is meant to be informative and can be used as a tool for LIS programs to assess their curriculums in comparison to the needs of eScience and other data-driven and networked research. Finally, this investigation will provide awareness and insight into the services needed to support a thriving eScience and data-driven research community to the LIS profession.

Internet Civil Liberties in the U.S. and the Protection of the Modern Terrorist

This capstone examines the civil liberties of the modern terrorist and explicates the right to freedom of speech for terrorist organizations and their use of the internet. Terrorist organizations use the internet to promote ideas, recruit members, organize the flow of information, and coordinate actions. During the war on terror the US Patriot Act became law allowing for U.S. government censorship and surveillance of internet traffic and many believe these acts are a threat to civil liberties. Terrorist organizations have the right to express their views, however unpopular, and censoring or restricting web sites diminishes civil liberties for all, which democracies and liberal societies are founded upon.

Herramientas Web en el proceso de enseñanza y aprendizaje del ciberperiodismo en la Comunidad Valenciana

Internet es un recurso de trabajo imprescindible en la tarea del ciberperiodista. Los profesionales de este campo utilizan la red como fuente de información, para crear, editar y distribuir contenidos informativos. Estas nuevas formas de trabajo, apoyadas en entornos telemáticos, se están haciendo extensibles a la universidad española, donde se está produciendo un proceso de adaptación de metodologías, técnicas y herramientas en los estudios de Periodismo. Para facilitar este proceso de ajuste por parte de los profesores de ciberperiodismo, esta investigación pretende establecer una tipología del uso de estos instrumentos en línea según los objetivos planteados en las guías docentes. Para ello, se han estudiado los programas de las asignaturas relacionadas con la docencia del ciberperiodismo en la Comunidad Valenciana. Se han seleccionado los instrumentos Web más utilizados por los profesores y se han organizado en una tabla según criterios de finalidad, acción y tipo de interacción que realiza el alumno con las herramientas y asimismo los objetivos ciberperiodísticos que pueden lograrse con cada una de ellas. La tabla ofrece información general de cada herramienta. El propósito es facilitar a los profesores un criterio de selección para elegir y profundizar en los espacios e instrumentos docentes más adecuados según las competencias que el alumno debe adquirir durante el proceso de enseñanza y aprendizaje en estos estudios.

Work-related health problems among resident immigrant workers in Italy and Spain

Background: in both Spain and Italy the number of immigrants has strongly increased in the last 20 years, currently representing more than the 10% of workforce in each country. The segregation of immigrants into unskilled or risky jobs brings negative consequences for their health. The objective of this study is to compare prevalence of work-related health problems between immigrants and native workers in Italy and Spain. Methods: data come from the Italian Labour Force Survey (n=65 779) and Spanish Working Conditions Survey (n=11 019), both conducted in 2007. We analyzed merged datasets to evaluate whether interviewees, both natives and migrants, judge their health being affected by their work conditions and, if so, which specific diseases. For migrants, we considered those coming from countries with a value of the Human Development Index lower than 0.85. Logistic regression models were used, including gender, age, and education as adjusting factors. Results: migrants reported skin diseases (Mantel-Haenszel pooled OR=1.49; 95%CI: 0.59-3.74) and musculoskeletal problems among those employed in agricultural sector (Mantel-Haenszel pooled OR=1.16; 95%CI: 0.69-1.96) more frequently than natives; country-specific analysis showed higher risks of musculoskeletal problems among migrants compared to the non-migrant population in Italy (OR=1.17; 95% CI: 0.48-1.59) and of respiratory problems in Spain (OR=2.02; 95%CI: 1.02-4.0). In both countries the risk of psychological stress was predominant among national workers. Conclusions: this collaborative study allows to strength the evidence concerning the health of migrant workers in Southern European countries.

Profiling in sport using momentum and perturbations

Examining a team’s performance from a physical point of view their momentum might indicate unexpected turning points in defeat or success. Physicists describe this value as to require some effort to be started, but also that it is relatively easy to keep it going once a sufficient level is reached (Reed and Hughes, 2006). Unlike football, rugby, handball and many more sports, a regular volleyball match is not limited by time but by points that need to be gathered. Every minute more than one point is won by either one team or the other. That means a series of successive points enlarges the gap between the teams making it more and more difficult to catch up with the leading one. This concept of gathering momentum, or the reverse in a performance, can give the coaches, athletes and sports scientists further insights into winning and losing performances. Momentum investigations also contain dependencies between performances or questions if future performances are reliant upon past streaks. Squash and volleyball share the characteristic of being played up to a certain amount of points. Squash was examined according to the momentum of players by Hughes et al. (2006). The initial aim was to expand normative profiles of elite squash players using momentum graphs of winners and errors to explore ‘turning points’ in a performance. Dynamic systems theory has enabled the definition of perturbations in sports exhibiting rhythms (Hughes et al., 2000; McGarry et al., 2002; Murray et al., 2008), and how players and teams cause these disruptions of rhythm can inform on the way they play, these techniques also contribute to profiling methods. Together with the analysis of one’s own performance it is essential to have an understanding of your oppositions’ tactical strengths and weaknesses. By modelling the oppositions’ performance it is possible to predict certain outcomes and patterns, and therefore intervene or change tactics before the critical incident occurs. The modelling of competitive sport is an informative analytic technique as it directs the attention of the modeller to the critical aspects of data that delineate successful performance (McGarry & Franks, 1996). Using tactical performance profiles to pull out and visualise these critical aspects of performance, players can build justified and sophisticated tactical plans. The area is discussed and reviewed, critically appraising the research completed in this element of Performance Analysis.

Apoyo social formal a un grupo de madres con hijos menores de un año

Objetivo: este trabajo pretende analizar el apoyo social formal a un grupo de madres con hijos menores de un año. Método: estudio cualitativo, descriptivo interpretativo, en el cual participaron diez mujeres en un grupo focal que se reunió en siete ocasiones. Resultados: a partir del análisis de contenido de las dinámicas grupales se detecta que el apoyo formal informativo es el más frecuente y resulta difícil separarlo del emocional. Los profesionales, a través del apoyo informativo, tratan temas relacionados con la promoción de la salud y prevención de la enfermedad y acompañan a las madres en este rol. Conclusión: para las madres el apoyo formal brindado por el personal de enfermería es positivo y percibido como un refuerzo en su vivencia de la maternidad, y debe estar enmarcado en un contexto cultural.

Análisis relacional sobre el grado de credibilidad entre diferentes medios de comunicación en materia de drogas

Antecedentes: En la actualidad los medios de comunicación se constituyen como la principal fuente de información de la que se nutren los jóvenes. No obstante, y pese a la gran cantidad y variedad de mensajes disponibles, la información no siempre se construye adecuadamente debido a las frecuentes discrepancias con las que los medios de comunicación suelen exponerla. En referencia al tratamiento informativo que los diversos medios confieren a temas relacionados con la salud en general, y de forma más concreta sobre temas referentes a las drogas, es muy frecuente que la percepción tienda hacia un sensacionalismo exacerbado y una gran descontextualización de la información, lo que incide negativamente en la credibilidad que se otorga a los diversos medios. Metodología: En este estudio piloto se analiza la relación existente entre el grado de credibilidad que los jóvenes encuestados conceden a los distintos medios de comunicación, tanto si se refiere a información en general como si se refiere a temas sobre drogas. De igual modo, se indaga la relación existente entre el grado de información objetivo que poseen los sujetos sobre las distintas sustancias y la percepción del tratamiento que los medios de comunicación dan a la información sobre drogas. Para ello, participaron en el estudio 115 alumnos (27% varones y 73% mujeres) de primero de grado en Psicología, de la Universidad Miguel Hernández de Elche (Alicante-España). Conclusiones: Los resultados muestran correlaciones positivas del grado de credibilidad otorgado a los diversos medios, tanto si se trata sobre temas de información general como sobre temas relacionados con las drogas. Por otra parte, los jóvenes mantienen diferentes percepciones sobre el tratamiento que realizan los medios de comunicación de las noticias y contenidos sobre drogas, en función del nivel de información objetivo que poseen de las distintas sustancias de abuso.

Feedbacks between vegetation pattern and resource loss dramatically decrease ecosystem resilience and restoration potential in a simple dryland model

Conceptual frameworks of dryland degradation commonly include ecohydrological feedbacks between landscape spatial organization and resource loss, so that decreasing cover and size of vegetation patches result in higher water and soil losses, which lead to further vegetation loss. However, the impacts of these feedbacks on dryland dynamics in response to external stress have barely been tested. Using a spatially-explicit model, we represented feedbacks between vegetation pattern and landscape resource loss by establishing a negative dependence of plant establishment on the connectivity of runoff-source areas (e.g., bare soils). We assessed the impact of various feedback strengths on the response of dryland ecosystems to changing external conditions. In general, for a given external pressure, these connectivity-mediated feedbacks decrease vegetation cover at equilibrium, which indicates a decrease in ecosystem resistance. Along a gradient of gradual increase of environmental pressure (e.g., aridity), the connectivity-mediated feedbacks decrease the amount of pressure required to cause a critical shift to a degraded state (ecosystem resilience). If environmental conditions improve, these feedbacks increase the pressure release needed to achieve the ecosystem recovery (restoration potential). The impact of these feedbacks on dryland response to external stress is markedly non-linear, which relies on the non-linear negative relationship between bare-soil connectivity and vegetation cover. Modelling studies on dryland vegetation dynamics not accounting for the connectivity-mediated feedbacks studied here may overestimate the resistance, resilience and restoration potential of drylands in response to environmental and human pressures. Our results also suggest that changes in vegetation pattern and associated hydrological connectivity may be more informative early-warning indicators of dryland degradation than changes in vegetation cover.