963 research outputs found

    Microcystins in components of twelve New Hampshire lakes of varied trophic status

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    Cyanobacteria toxins, called microcystins (MCs), were found in components of twelve, stratified New Hampshire (USA) lakes of varied trophic status during the summer of 1998. A sensitive ELISA method detected MC levels in whole lakewater, grazable phytoplankton fractions (\u3c30 mm), net phytoplankton (\u3e 375 µm), and isolated copepod and cladoceran (Daphnia sp.) samples. Whole lakewater (WLW) and net phytoplankton MC concentrations ranged between 9 and 165 ng MC L-1 and 0.2 and 2031 mg MC g-1-dry wt, respectively. Lakewater MC concentrations correlated with total epilimnetic phosphorus and total epilimnetic chlorophyll a concentrations and inversely with Secchi disk depth. The filter-feeding cladoceran (daphnid) and omnivorous copepod components of the zooplankton were separated and assayed independently for MCs. The cladoceran component accumulated between 7 and 2800 µg MC g-1-dry wt. in 10 of the lakes. The copepod component accumulated similar levels (4 and 2400 µg MC g-1 dry-wt.) in all lakes. Toxin accumulation by zooplankton directly correlated with lakewater and net phytoplankton MC concentrations. The highest levels were found in Silver Lake, a productive lake where Microcystis aeruginosa blooms frequently occur. It is particularly noteworthy that MC levels were also detected by ELISA methods in Russell Pond, a pristine, deep mountain lake of low productivity. The results emphasize the importance of including oligotrophic lakes and water supplies in monitoring programs for MCs to ensure the safety of animals and humans utilizing them for drinking and recreation

    A Target Restricted Assembly Method (TRAM) for Phylogenomics

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    While next generation sequencing technology can produce sequences covering the entire genome, assembly and annotation are still prohibitive steps for many phylogenomics applications. Here we describe a method of Target Restricted Assembly (TRAM) of a single lane of Illumina sequences for genes of relevance to phylogeny reconstruction, i.e. single copy protein-coding genes. This method has the potential to produce a data set of hundreds of genes using only one Illumina lane per taxon

    Giant Planet Occurrence in the Stellar Mass-Metallicity Plane

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    Correlations between stellar properties and the occurrence rate of exoplanets can be used to inform the target selection of future planet search efforts and provide valuable clues about the planet formation process. We analyze a sample of 1194 stars drawn from the California Planet Survey targets to determine the empirical functional form describing the likelihood of a star harboring a giant planet as a function of its mass and metallicity. Our stellar sample ranges from M dwarfs with masses as low as 0.2 Msun to intermediate-mass subgiants with masses as high as 1.9 Msun. In agreement with previous studies, our sample exhibits a planet-metallicity correlation at all stellar masses; the fraction of stars that harbor giant planets scales as f \propto 10^{1.2 [Fe/H]}. We can rule out a flat metallicity relationship among our evolved stars (at 98% confidence), which argues that the high metallicities of stars with planets are not likely due to convective envelope "pollution." Our data also rule out a constant planet occurrence rate for [Fe/H]< 0, indicating that giant planets continue to become rarer at sub-Solar metallicities. We also find that planet occurrence increases with stellar mass (f \propto Mstar), characterized by a rise from 3.5% around M dwarfs (0.5 Msun) to 14% around A stars (2 Msun), at Solar metallicity. We argue that the correlation between stellar properties and giant planet occurrence is strong supporting evidence of the core accretion model of planet formation.Comment: Fixed minor typos, modified the last paragraph of Section

    The Importance of the Interface between Humans and Computers on the Effectiveness of eHRM

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    Technology has had a dramatic impact on the practice of human resources, and its impact is rapidly increasing. Even so, little research has examined how to apply information systems and human-computer interaction principles to designing human resource information systems. In this paper, we focus more closely on the role that the interface between the computer and human play in the success of electronic human resource management. Specifically, we a) briefly review the individual requirements of several eHRM functions (e.g., e-recruiting, e-selection, e-learning, e- compensation/benefits), b) consider how an understanding of human computer interaction can facilitate the success of these systems, c) reviews research on technical issues associated with eHRM, and d) highlight how applying HCI principles can increase their effectiveness. In addition, we introduce the remaining seven papers in the special issue

    The Evolution of the Field of Human Resource Information Systems: Co-Evolution of Technology and HR Processes

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    In this paper, we review the professional and academic development of the human resource information systems (HRIS) field to assess its progress and suggest ways for moving research forward. To do so, we examine the interplay between the evolution of technology and the HR field through four key eras of technology: 1) mainframe, 2) client server, 3) ERP and Web-based systems, and 4) cloud-based systems. In each era, we discuss how HR practices and requirements drove the need for the use of these systems and how these systems allowed the HR field to evolve. In addition, we trace the HRIS subfield and its relation to the technological evolutions occurring in the HR field. Somewhat surprisingly, we found that much of the research on the use of technology to support HR has occurred only in the last 15-20 years as a response to the use of the Web as a medium for delivering HRIS. We conclude by discussing how scholars from the information systems and human resources fields can come together to help advance HRIS

    Impact of Human Resource Information System Policies on Privacy

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    Organizations are increasingly using human resource information systems (HRIS) to collect and store employee data to enhance employment decision making. In this paper, using a 2 x 2 x 2 experimental design, we 1) examine the effects of three HRIS policies on employees’ perceptions of invasion of privacy, 2) assess the moderating effects of amount of work experience on the relations between these HRIS policies and employees’ perceptions of invasion of privacy and 3) discuss the implications of these findings for developing fair information policies. Results revealed that individuals perceived a HRIS was more of an invasion of privacy when HRIS data were used for only the benefit of the organization than when it was used to benefit employees. In addition, the results indicated that individuals perceived that a HRIS was more invasive of privacy when the data were accessed by supervisors than when they were accessed by the HR department only. Furthermore, individuals\u27 amount of work experience moderated the relations between (a) purpose of the data collection, and (b) access to data and perceptions of invasion of privacy. Implications for theory, research, and practice are discussed

    Intra and Inter-Tester Reliability for Lumbar Flexion and Extension Using the Dualer Digital Inclinometer

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    Purpose: The purpose of this study was to determine the intra- and inter-tester reliability of the DualerTM Digital Inclinometer when measuring lumbar flexion and extension. Past studies examining reliability of inclinometers have reported variable results. Few studies in the literature have sought to determine the reliability of the Dualer™ Digital Inclinometer for measuring lumbar flexion and extension. Methods: The subjects who participated in this study were university students between 20 and 41 years of age without a significant history of back pain (n=22). Two testers measured each subject\u27s lumbar flexion and extension, hip flexion and extension, and straight leg raise during each of two measuring sessions. Results: Intraclass correlation coefficients (ICC) as an indication of intra-tester reliability for lumbar flexion, extension and total motion for tester one were .59, .73, and .76 respectively. ICC values for lumbar flexion, extension and total motion for tester two were .67, .74, and .70, respectively. Inter-tester reliability was not established because of insufficient intra-tester reliability. Discussion: Many factors may have contributed to the lack of high intra-tester reliability. The subject, tester, and sensitivity of the instrument or procedure may have caused errors. In order to use the Dualer™ with the currently recommended procedure clinically, the clinician must be aware of the limitations and seek to minimize the sources of error

    Reducing Sexual Risk among Racial/ethnic-minority Ninth Grade Students: Using Intervention Mapping to Modify an Evidenced-based Curriculum

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    Background: Racial/ethnic-minority 9th graders are at increased risk for teen pregnancy, HIV, and STIs compared to their White peers. Yet, few effective sexual health education programs exist for this population. Purpose: To apply IM Adapt—a systematic theory- and evidence-based approach to program adaptation—to modify an effective middle school sexual health education curriculum, It’s Your Game…Keep It Real! (IYG), for racial/ethnic-minority 9th graders. Methods: Following the six steps of IM Adapt, we conducted a needs assessment to describe the health problems and risk behaviors of the new population; reviewed existing evidence-based programs; assessed the fit of IYG for the new population regarding behavioral outcomes, determinants, change methods, delivery, and implementation; modified materials and activities; planned for implementation and evaluation. Results: Needs assessment findings indicated that IYG targeted relevant health and risk behaviors for racial/ethnic-minority 9th graders but required additional focus on contraceptive use, dating violence prevention, active consent, and access to healthcare services. Behavioral outcomes and matrices of change objectives for IYG were modified accordingly. Theoretical methods and practical applications were identified to address these behavioral outcomes, and new activities developed. Youth provided input on activity modifications. School personnel guided modifications to IYG’s scope and sequence, and delivery. The adapted program, Your Game, Your Life, comprised fifteen 30-minute lessons targeting determinants of sexual behavior and healthy dating relationships. Pilot-test data from 9th graders in two urban high schools indicate promising results. Conclusion: IM Adapt provides a systematic theory- and evidence-based approach for adapting existing evidence-based sexual health education curricula for a new population whilst retaining essential elements that made the original program effective. Youth and school personnel input ensured that the adapted program was age-appropriate, culturally sensitive, and responsive to the needs of the new population. IM Adapt contributes to the limited literature on systematic approaches to program adaptation
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