8,009 research outputs found

    A new species of \u3cem\u3eKochius\u3c/em\u3e from Avra Valley, southern Arizona (Scorpiones: Vaejovidae)

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    A new scorpion species, Kochius colluvius sp. n. is described (Scorpiones: Vaejovidae). This small brown species is found in the Avra Valley near Tucson, Arizona, USA. It appears to be most similar to Kochius sonorae (Williams, 1971) and K. hirsuticauda (Banks, 1910). On all fingers examined, the fixed finger has 6 ID denticles and the movable finger has 7. There is no scalloping of the chela fingers. This species differs from all other vaejovids in Arizona by having a coarsely granulated exoskeleton

    Unified Total Synthesis of the Brevianamide Alkaloids Enabled by Chemical Investigations into their Biosynthesis

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    The bicyclo[2.2.2]diazaoctane alkaloids are a vast group of natural products which have been the focus of attention from the scientific community for several decades. This interest stems from their broad range of biological activities, their diverse biosynthetic origins, and their topologically complex structures, which combined make them enticing targets for chemical synthesis. In this article, full details of our synthetic studies into the chemical feasibility of a proposed network of biosynthetic pathways towards the brevianamide family of bicyclo[2.2.2]diazaoctane alkaloids are disclosed. Insights into issues of reactivity and selectivity in the biosynthesis of these structures have aided the development of a unified biomimetic synthetic strategy, which has resulted in the total synthesis of all known bicyclo[2.2.2]diazaoctane brevianamides and the anticipation of an as-yet-undiscovered congener

    Wildlife Damage to Seedlings in Reforested in Hardwood Sites in Mississippi

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    Herbivory assessments were conducted on seven reforested sites that were less than one year old in the following Mississippi counties: Bolivar, Leflore, and Attala. At each site, 100ft. x 100 ft. plots were established and randomly selected seedlings were marked and measured to determine seedling species, height, condition, survival, and type and extent of animal feeding sign. Surveys were conducted in March/April, May, and August 2004. Herbivory rates were highest during May with approximately 47% of seedlings showing signs of herbivory. In March/ April and August, the percentage of seedlings exhibiting signs of herbivory was 37% and 30%, respectively. Foraging by white-tailed deer (Odocoileus virginianus) was recorded on \u3e 90% of the damaged seedlings during each survey. Tree mortality for all study sites and tree species was negligible, with the highest amount (7%) recorded during August, despite the recorded rates of herbivory by white-tailed deer. Herbivory by rabbits (Sylvilagus spp.) and rodents occurred on approximately 6% of the seedlings throughout the 2004 growing season

    Mood and Performance Anxiety in High School Basketball Players: A Pilot Study

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    International Journal of Exercise Science 10(4): 604-618, 2017. Participation in competitive sport may impact psychological measures, such as mood and performance anxiety, which in turn may impact enjoyment, adherence, continued participation, and so on. This study assessed the feasibility – in terms of process, resources, management, and potential scientific value– of measuring the effect of varying competitive challenges upon the mood and performance anxiety measures of high school athletes. The participants (n=12) consisted of the boys’ varsity basketball team at a high school in a rural Midwestern community. Participants completed the Profile of Mood States (POMS) to assess mood and the Sport Anxiety Scale-2 (SAS-2) to assess performance anxiety, respectively. Survey administration occurred at baseline and prior to games designated as non-conference, conference, and state tournament. A-priori feasibility measures were achieved in this prospective design. Significant correlations on the subscale measures were found on the POMS and SAS-2 administered before the four conditions in this study; Chronbach’s alpha ranged from 0.54- 0.94 across conditions for POMS subscales, and Chronbach’s alpha ranged from 0.73-0.97 across all conditions for SAS-2 subscales, respectively. Significant differences were found across conditions in the POMS subscale confusion [F(3,33) = 5.71, p = 0.01] and in the SAS-2 subscale worry [F(3,33) = 6.13, p=0.01]. These preliminary findings suggest that the competitive conditions in this study significantly affected some measures of mood and performance anxiety in high school basketball players. These findings warrant further investigation, as well as suggest coaches could gather such information from their players, ultimately aiding in player development and team performance

    The substellar mass function in the central region of the open cluster Praesepe from deep LBT observations

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    Studies of the mass function (MF) of open clusters of different ages allow us to probe the efficiency with which brown dwarfs (BDs) are evaporated from clusters to populate the field. Surveys in old clusters (age > 100 Myr) do not suffer so severely from several problems encountered in young clusters, such as intra-cluster extinction and large uncertainties in BD models. Here we present the results of a deep photometric survey to study the MF of the old open cluster Praesepe (age 590 Myr and distance 190 pc), down to a 5 sigma detection limit at i~25.6 mag (~40M_Jup). We identify 62 cluster member candidates, of which 40 are substellar, from comparison with predictions from a dusty atmosphere model. The MF rises from the substellar boundary until ~60M_Jup and then declines. This is quite different from the form inferred for other open clusters older than 50 Myr, but seems to be similar to those found in very young open cluster, whose MFs peak at ~10M_Jup. Either Praesepe really does have a different MF from other clusters or they had similar initial MFs but have differed in their dynamical evolution. We further have identified six foreground T dwarf candidates towards Praesepe, which require follow-up spectroscopy to confirm their nature.Comment: 8 pages, 5 figures, to appear in the online proceedings of the Cool Stars 16 conferenc

    The medium-term sustainability of organisational innovations in the national health service

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    Background: There is a growing recognition of the importance of introducing new ways of working into the UK's National Health Service (NHS) and other health systems, in order to ensure that patient care is provided as effectively and efficiently as possible. Researchers have examined the challenges of introducing new ways of working-'organisational innovations'-into complex organisations such as the NHS, and this has given rise to a much better understanding of how this takes place-and why seemingly good ideas do not always result in changes in practice. However, there has been less research on the medium-and longer-term outcomes for organisational innovations and on the question of how new ways of working, introduced by frontline clinicians and managers, are sustained and become established in day-to-day practice. Clearly, this question of sustainability is crucial if the gains in patient care that derive from organisational innovations are to be maintained, rather than lost to what the NHS Institute has called the 'improvement-evaporation effect'. Methods: The study will involve research in four case-study sites around England, each of which was successful in sustaining its new model of service provision beyond an initial period of pilot funding for new genetics services provided by the Department of Health. Building on findings relating to the introduction and sustainability of these services already gained from an earlier study, the research will use qualitative methods-in-depth interviews, observation of key meetings, and analysis of relevant documents-to understand the longer-term challenges involved in each case and how these were surmounted. The research will provide lessons for those seeking to sustain their own organisational innovations in wide-ranging clinical areas and for those designing the systems and organisations that make up the NHS, to make them more receptive contexts for the sustainment of innovation. Discussion: Through comparison and contrast across four sites, each involving different organisational innovations, different forms of leadership, and different organisational contexts to contend with, the findings of the study will have wide relevance. The research will produce outputs that are useful for managers and clinicians responsible for organisational innovation, policy makers and senior managers, and academics

    Impact of age norms and stereotypes on managers' hiring decisions of retirees

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    Purpose -Our study investigates the role of managers in the re-employment of early retirees and asks what the effect is of managers’ age norms and stereotypes on managers’ employment decisions. Design/methodology/approach- A combination of a factorial study and a survey was conducted. First, information on the age norms and stereotypes was collected. Secondly, profiles of hypothetical retired job applicants were presented to the employers, who were asked to make a specific hiring decision. The information collected during both studies was combined in the analysis and multilevel models were estimated. Findings -The results indicate that higher age norms result in a higher propensity to hire an early retiree. Stereotypes, by contrast, do not influence managers’ decisions. Early retirees’ chances for re-employment are also related to their own circumstances (physical appearance and relevant experience) and organisational forces, as they are hired when organisations face labour force shortages. Research limitation / implications – with the use of vignettes study we deal with hypothetical hiring situation. Originality value- Although the effect of age norms and age stereotypes has been often suggested, not much empirical evidence was presented to support this notion. Our study estimates the effect of age norms and stereotypes on hiring decision. key words: bridge employment; early retirees; age norms; age stereotypes; multilevel models.

    A large spectroscopic sample of L and T dwarfs from UKIDSS LAS : peculiar objects, binaries, and space density

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    This is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record [F. Marocco, et al, 'A large spectroscopic sample of L and T dwarfs from UKIDSS LAS: peculiar objects, binaries, and space density', MNRAS, Vol. 449)4): 3651-3692, April 2015] is available online at: https://doi.org/10.1093/mnras/stv530.We present the spectroscopic analysis of a large sample of late-M, L, and T dwarfs from UKIDSS. Using the YJHK photometry from ULAS and the red-optical photometry from SDSS we selected a sample of 262 brown dwarf candidates and we followed-up 196 of them using X-shooter on the VLT. The large wavelength coverage (0.30-2.48 μ\mum) and moderate resolution (R~5000-9000) of X-shooter allowed us to identify peculiar objects including 22 blue L dwarfs, 2 blue T dwarfs, and 2 low gravity M dwarfs. Using a spectral indices-based technique we identified 27 unresolved binary candidates, for which we determined the spectral type of the potential components via spectral deconvolution. The spectra allowed us to measure the equivalent width of the prominent absorption features and to compare them to atmospheric models. Cross-correlating the spectra with a radial velocity standard, we measured the radial velocity for our targets, and we determined the distribution of the sample, which is centred at -1.7±\pm1.2 km s−1^{-1} with a dispersion of 31.5 km s−1^{-1}. Using our results we estimated the space density of field brown dwarfs and compared it with the results of numerical simulations. Depending on the binary fraction, we found that there are (0.85±\pm0.55) x 10−3^{-3} to (1.00±\pm0.64) x 10−3^{-3} objects per cubic parsec in the L4-L6.5 range, (0.73±\pm0.47) x 10−3^{-3} to (0.85±\pm0.55) x 10−3^{-3} objects per cubic parsec in the L7-T0.5 range, and (0.74±\pm0.48) x 10−3^{-3} to (0.88±\pm0.56) x 10−3^{-3} objects per cubic parsec in the T1-T4.5 range. There seem to be an excess of objects in the L/T transition with respect to the late T dwarfs, a discrepancy that could be explained assuming a higher binary fraction than expected for the L/T transition, or that objects in the high-mass end and low-mass end of this regime form in different environments, i.e. following different IMFs.Peer reviewe

    The discovery of a T6.5 subdwarf

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    We report the discovery of ULAS J131610.28+075553.0, an sdT6.5 dwarf in the UKIDSS Large Area Survey 2 epoch proper motion catalogue. This object displays significant spectral peculiarity, with the largest yet seen deviations from T6 and T7 templates in the Y and K bands for this subtype. Its large, similar to 1 arcsec yr(-1), proper motion suggests a large tangential velocity of V-tan approximate to 240-340 km s(-1), if we assume its M-J lies within the typical range for T6.5 dwarfs. This makes it a candidate for membership of the Galactic halo population. However, other metal-poor T dwarfs exhibit significant under luminosity both in specific bands and bolometrically. As a result, it is likely that its velocity is somewhat smaller, and we conclude it is a likely thick disc or halo member. This object represents the only T dwarf earlier than T8 to be classified as a subdwarf, and is a significant addition to the currently small number of known unambiguously substellar subdwarfs.Peer reviewe
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