4,399 research outputs found

    The variegated mud-loving beetles (Coleoptera: Heteroceridae) of Mississippi and Alabama, with discussion and keys to the species occurring in the southeastern United States

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    We review the variegated mud-loving beetle fauna of the southeastern United States (Coleoptera: Heteroceridae), with an emphasis on Mississippi and Alabama. A key is presented to all species known to occur in the southeastern US, and includes several extra-limital species. Descriptions, illustrations and distribution maps are presented for each species. One new species, Tropicus nigrellus, is described and a lectotype is designated for Heterocerus schwarzi Horn. Our molecular data suggest that many previously recognized generic concepts are unnatural. As a result, the following generic synonymies are proposed: Culmus Pacheco 1964, Damfius Pacheco 1964, Efflagitatus Pacheco 1964, Erus Pacheco 1964, Filiolus Pacheco 1964, Gradus Pacheco 1964, Lanternarius Pacheco 1964, Lapsus Pacheco 1964, Neoheterocerus Pacheco 1964, Olmedous Pacheco 1964 and Peditatus Pacheco 1964 are synonyms of Heterocerus Fabricius; the genera Centariatus Pacheco 1964, Explorator Pacheco 1964, and Microaugyles Pacheco 1964 are synonyms of Augyles Schiödte. New combinations proposed and used in this paper include: Augyles auromicans (Kiesenwetter 1851, Heterocerus), Heterocerus parrotus (Pacheco 1964, Lanternarius), Heterocerus sandersoni (Pacheco 1964, Neoheterocerus) and Heterocerus selanderi (Pacheco 1964, Efflagitatus), Heterocerus texanus (Pacheco 1964, Peditatus). Other new combinations for North American species formed as a result of these generic reconfigurations, but not used in this paper, include: Heterocerus inciertus (Pacheco 1964, Damfius), Heterocerus longilobulus (Pacheco 1964, Neoheterocerus), Heterocerus sinuosus (Pacheco 1964, Lanternarius), Augyles canadensis (Fall 1920, Heterocerus), Augyles compactus (Fall 1937, Heterocerus), Augyles moleculus (Fall 1920, Heterocerus) and Augyles mundulus (Fall 1920, Heterocerus). New combinations for South American species suggested by molecular data, all originally described in the genus Efflagitatus, include: Heterocerus boliviensis (Pacheco 1964), Heterocerus freudei (Pacheco 1973), Heterocerus furmidus (Pacheco 1964), Heterocerus ingeniosus (Pacheco 1964), Heterocerus meridianus (Pacheco 1975), Heterocerus reticulatus (Pacheco 1964), Heterocerus solitarius (Pacheco 1973), Heterocerus splendidus (Pacheco 1964), Heterocerus tortuosus (Pacheco 1973), Heterocerus woodruffi (Pacheco 1975). No new combinations involving synonymy within the genera Culmus, Erus, Filiolus, Gradus, Lapsus, and Olmedous were proposed because all included species were originally described as Heterocerus

    Inferring individual attributes from search engine queries and auxiliary information

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    Internet data has surfaced as a primary source for investigation of different aspects of human behavior. A crucial step in such studies is finding a suitable cohort (i.e., a set of users) that shares a common trait of interest to researchers. However, direct identification of users sharing this trait is often impossible, as the data available to researchers is usually anonymized to preserve user privacy. To facilitate research on specific topics of interest, especially in medicine, we introduce an algorithm for identifying a trait of interest in anonymous users. We illustrate how a small set of labeled examples, together with statistical information about the entire population, can be aggregated to obtain labels on unseen examples. We validate our approach using labeled data from the political domain. We provide two applications of the proposed algorithm to the medical domain. In the first, we demonstrate how to identify users whose search patterns indicate they might be suffering from certain types of cancer. In the second, we detail an algorithm to predict the distribution of diseases given their incidence in a subset of the population at study, making it possible to predict disease spread from partial epidemiological data

    Space and place as expressive categories in videogames

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    This thesis sets out to explore some of the ways in which videogames use space as a means of expression. This expression takes place in two registers: representation and embodiment. Representation is understood as a form of expression in which messages and ideas are communicated. Embodiment is understood as a form of expression in which the player is encouraged to take up a particular position in relation to the game. This distinction between representation and embodiment is useful analytically but the thesis attempts to synthesise these modes in order to account for the experience of playing videogames, where representation and embodiment are constantly happening and constantly influencing and shaping each other. Several methods are developed to analyse games in a way that brings these two modes to the fore. The thesis attempts to arrive at a number of spatial aesthetics of videogames by adapting methods from game studies, literary criticism, phenomenology, onomastics (the study of names), cartographic theory, choreography and architectural and urban formation analysis.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    A SQUAMOSA MADS-box gene involved in the regulation of anthocyanin accumulation in bilberry fruits

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    Anthocyanins are important health promoting phytochemicals that are abundant in many fleshy fruits. Bilberry (Vaccinium myrtillus L.) is one of the best sources of these compounds. Here we report on the expression pattern and functional analysis of a SQUAMOSA (SQUA) class MADS-box transcription factor, VmTDR4, associated with anthocyanin biosynthesis in bilberry. Levels of VmTDR4 expression were spatially and temporally linked with colour development and anthocyanin-related gene expression. Virus induced gene silencing (VIGS) was used to suppress VmTDR4 expression in bilberry resulting in substantial reduction in anthocyanin levels in fully ripe fruits. Chalcone synthase was used a positive control in the VIGS experiments. Additionally, in sectors of fruit tissue in which the expression of the VmTDR4 gene was silenced, the expression of R2R3 MYB family transcription factors related to the biosynthesis of flavonoids were also altered. We conclude that VmTDR4 plays an important role in the accumulation of anthocyanins during normal ripening in bilberry; probably through direct or indirect control of transcription factors belonging to the R2R3 MYB family

    Cognitive and neural signatures of the APOE E4 allele in mid-aged adults

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    The apolipoprotein E (APOE) e4 allele is strongly associated with increased risk of cognitive impairments in older adulthood. There is also a possible link to enhanced cognitive performance in younger adults, and the APOE e4 allele may constitute an example of antagonistic pleiotropy. The aim of this work was to investigate the cognitive and neural (functional) effects of the APOE e4 allele during mid-age (45-55 years), where a transition toward cognitive deficit might be expected. APOE e4 carriers (e4+) were compared with non-e4 carriers (e4-) on tasks of sustained and covert attention and prospective memory, and functional magnetic resonance imaging data acquired. Performance by e4+ was equivalent or better than e4- on all 3 tasks, although performance benefits were less pronounced than in youth. Neurally, e4+ showed less task-related recruitment of extrastriate and parietal areas. This became more evident when neural activation data were compared with that of young adults acquired in a parallel study. As expected, mid-age participants showed more diffuse neural activation. Notable was the fact that e4+ showed a relative inability to recruit parietal regions as they aged. This was coupled with a tendency to show greater recruitment of frontal regions, and underactivation of extrastriate visual regions. Thus, mid-age e4+ show a pattern of neural recruitment usually seen later in life, possibly reflecting the source of an accelerated aging profile that describes the e4 genotype

    Rhenium Complexes Bearing Tridentate and Bidentate Phosphinoamine Ligands in the Production of Biofuel Alcohols via the Guerbet Reaction

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    We report a variety of rhenium complexes supported by bidentate and tridentate phosphinoamine ligands and their use in the formation of the advanced biofuel isobutanol from methanol and ethanol. Rhenium pincer complexes 1–3 are effective catalysts for this process, with 2 giving isobutanol in 35% yields, with 97% selectivity in the liquid fraction, over 16 h with catalyst loadings as low as 0.07 mol %. However, these catalysts show poorer overall selectivity, with the formation of a significant amount of carboxylate salt solid byproduct also being observed. Production of the active catalyst 1d has been followed by 31P NMR spectroscopy, and the importance of the presence of base and elevated temperatures to catalyst activation has been established. Complexes supported by diphosphine ligands are inactive for Guerbet chemistry; however, complexes supported by bidentate phosphinoamine ligands show greater selectivity for isobutanol formation over carboxylate salts. The novel complex 7 was able to produce isobutanol in 28% yield over 17 h. The importance of the N–H moiety to the catalytic performance has also been established, giving further weight to the hypothesis that these catalysts operate via a cooperative mechanism

    Developmental neurotoxicants and the vulnerable male brain: a systematic review of suspected neurotoxicants that disproportionally affect males

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    The prevalence of neurodevelopmental disorders (NDs), including autism spectrum disorder, attention‑deficit/hyperactivity disorder, tic disorder, obsessive‑compulsive disorder, and emotional disturbances, has increased notably in the past few decades. To date, debate continues as to the origins of NDs. Increases in widespread exposure to and bioaccumulation of chemical neurotoxicants have paralleled the upsurge in NDs, and are suggested to be causal agents for NDs. One consistent aspect of NDs is the male preponderance. This review considers the issue of male preponderance by reviewing the gender‑specific neurotoxic effects of recognized neurotoxicant chemicals to assess their possible etiology in NDs. This investigation consisted of a systematic literature review of original studies published from 1970-2016 on suspected neurotoxicants, to examine whether they have a disproportionate adverse effect based on gender. Based on that review, the neurotoxicants exhibiting consistent gender‑specific effects, with exposed males being more affected (than similarly exposed females), were: lead, Thimerosal/ethylmercury, some organochlorine pesticides (e.g., dieldrin, endosulfan, and heptachlor), and air pollution. The next group identified were neurotoxicants exhibiting gender‑specific neurotoxic effects, with males being somewhat (but not consistently) more affected than females: mercury vapor, polychlorinated biphenyls (PCBs), and organophosphate pesticides. Finally, there was a group of studies in which the neurotoxicants exhibited apparent gender‑related neurotoxic effects but failed to show whether exposed males were consistently more affected than females: inorganic mercury salts, methylmercury species, and certain endocrine disruptors (e.g., phthalates and BPA). The overall conclusion from the studies reviewed was that the brain in males is more vulnerable to many toxic exposures than it is in females. Evidence suggests that the reasons for the male brain being more vulnerable include: (1) greater glutathione availability in females; (2) greater sulfate‑based detoxification capacity in females; (3) potentiating effects of co‑exposure to neurotoxicants and testosterone; (4) greater neuroinflammatory response in males; (5) reduced vulnerability to oxidative stress in females; and (6) neuroprotective effects of female hormones (estrogen and progesterone), especially in the reduction of inflammation and oxidative stress

    Dark resonances as a probe for the motional state of a single ion

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    Single, rf-trapped ions find various applications ranging from metrology to quantum computation. High-resolution interrogation of an extremely weak transition under best observation conditions requires an ion almost at rest. To avoid line-broadening effects such as the second order Doppler effect or rf heating in the absence of laser cooling, excess micromotion has to be eliminated as far as possible. In this work the motional state of a confined three-level ion is probed, taking advantage of the high sensitivity of observed dark resonances to the trapped ion's velocity. Excess micromotion is controlled by monitoring the dark resonance contrast with varying laser beam geometry. The influence of different parameters such as the cooling laser intensity has been investigated experimentally and numerically

    Ultraviolet Emission Line Ratios of Cataclysmic Variables

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    We present a statistical analysis of the ultraviolet emission lines of cataclysmic variables (CVs) based on ≈430\approx 430 ultraviolet spectra of 20 sources extracted from the International Ultraviolet Explorer Uniform Low Dispersion Archive. These spectra are used to measure the emission line fluxes of N V, Si IV, C IV, and He II and to construct diagnostic flux ratio diagrams. We investigate the flux ratio parameter space populated by individual CVs and by various CV subclasses (e.g., AM Her stars, DQ Her stars, dwarf novae, nova-like variables). For most systems, these ratios are clustered within a range of ∼1\sim 1 decade for log Si IV/C IV ≈−0.5\approx -0.5 and log He II/C IV ≈−1.0\approx -1.0 and ∼1.5\sim 1.5 decades for log N V/C IV ≈−0.25\approx -0.25. These ratios are compared to photoionization and collisional ionization models to constrain the excitation mechanism and the physical conditions of the line-emitting gas. We find that the collisional models do the poorest job of reproducing the data. The photoionization models reproduce the Si IV/C IV line ratios for some shapes of the ionizing spectrum, but the predicted N V/C IV line ratios are simultaneously too low by typically ∼0.5\sim 0.5 decades. Worse, for no parameters are any of the models able to reproduce the observed He II/C IV line ratios; this ratio is far too small in the collisional and scattering models and too large by typically ∼0.5\sim 0.5 decades in the photoionization models.Comment: LaTeX format, uses aaspp4.sty, 28 pages, 11 Postscript figures, accepted for publication in The Astrophysical Journal 10/16/9
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