1,268 research outputs found

    Guide to the Common Fishes of South Dakota

    Get PDF
    South Dakota is home to more than 100 fish species. This guide is a reference to the most common 50 species. Included are tips for identification, distribution maps and brief life histories. Also included is a comprehensive listing of the known fish species in South Dakota

    Correlated interaction fluctuations in photosynthetic complexes

    Full text link
    The functioning and efficiency of natural photosynthetic complexes is strongly influenced by their embedding in a noisy protein environment, which can even serve to enhance the transport efficiency. Interactions with the environment induce fluctuations of the transition energies of and interactions between the chlorophyll molecules, and due to the fact that different fluctuations will partially be caused by the same environmental factors, correlations between the various fluctuations will occur. We argue that fluctuations of the interactions should in general not be neglected, as these have a considerable impact on population transfer rates, decoherence rates and the efficiency of photosynthetic complexes. Furthermore, while correlations between transition energy fluctuations have been studied, we provide the first quantitative study of the effect of correlations between interaction fluctuations and transition energy fluctuations, and of correlations between the various interaction fluctuations. It is shown that these additional correlations typically lead to changes in interchromophore transfer rates, population oscillations and can lead to a limited enhancement of the light harvesting efficiency

    EPR, Bell, and Quantum Locality

    Full text link
    Maudlin has claimed that no local theory can reproduce the predictions of standard quantum mechanics that violate Bell's inequality for Bohm's version (two spin-half particles in a singlet state) of the Einstein-Podolsky-Rosen problem. It is argued that, on the contrary, standard quantum mechanics itself is a counterexample to Maudlin's claim, because it is local in the appropriate sense (measurements at one place do not influence what occurs elsewhere there) when formulated using consistent principles in place of the inconsistent appeals to "measurement" found in current textbooks. This argument sheds light on the claim of Blaylock that counterfactual definiteness is an essential ingredient in derivations of Bell's inequality.Comment: Minor revisions to previous versio

    The construct of psychopathy in a Chilean prison population

    Get PDF
    Objective: To test the four-factor model of the Hare Psychopathy Checklist-Revised (PCL-R) empirical construct of psychopathy in a Chilean prison population by using instruments that supply different types of data. Methods: Two hundred and nine male inmates of the Prison of Los Andes, Chile, were evaluated. Confirmatory factor analysis was carried out with the PCL-R and the Self-Report of Psychopathy-III-Short Form (SRP-III-SF). Results: The distributions of total PCL-R and SRP-III-SF scores were normal (Kolmorogov-Smirnov [K-S] = 1.04, p = 0.230; K-S = 0.812, p = 0.525, respectively), with means of 20.9±6.8 for the former and 61.6±15.2 for the latter. Model fit was good for the PCL-R (Tucker Lewis index [TLI] = 0.96; root mean square error of approximation [RMSEA] = 0.04) and for the SRP-SF (TLI = 0.94, RMSEA = 0.04). Conclusions: The results obtained with the PCL-R and the SRP-SF showed adequate fit to the empirical four-factor model of psychopathy and support this model. As foreseeable, fit was better for the PCL-R, which combines several sources of information.Facultad de Ciencias Médica

    A plea for scale, and why it matters for invasive species management, biodiversity and conservation

    Get PDF
    Invasive species are suspected to be major contributors to biodiversity declines worldwide. Counterintuitively, however, invasive species effects are likely scale dependent and are hypothesized to be positively related to biodiversity at large spatial scales. Past studies investigating the effect of invasion on biodiversity have been mostly conducted at small scales (\u3c100 m2) that cannot represent large dynamic landscapes by design. Therefore, replicated experimental evidence supporting a negative effect of invasive plants on biodiversity is lacking across many landscape types, including large grasslands. We collected data across eight large (333–809 ha) grassland landscapes managed with pyric herbivory—that is the recoupling of fire and grazing—to test how an invasive legume Lespedeza cuneata affected plant and bird communities at spatial grains ranging from 0.1 m2 to \u3e3,000,000 m2. Lespedeza cuneata invasion effects on grassland plant diversity and composition changed with scale, being negative at small spatial grains (0.1 m2) and neutral or positive at large spatial grains (\u3e3,000,000 m2). Lespedeza cuneata abundance did not significantly affect bird diversity at any spatial grain measured. Lespedeza cuneata may negatively affect biodiversity if abundances are greater than those observed in this study. However, previous research suggests that Lespedeza cuneata may not be capable of exceeding 20% canopy cover across large landscapes (\u3e400 ha). Control and eradication strategies can be costly and are fraught with risk. If data do not clearly support a negative Lespedeza cuneata abundance–biodiversity relationship, and if invasion is spatially limited across large landscapes, ongoing control and eradication efforts may be unwarranted and ineffective. Synthesis and applications: Invasive species effects gleaned from small-scale studies may not reliably predict their effects at larger scales. Although we recognize the importance of small-scale studies in potentially isolating individual mechanisms, management strategies based solely on results from small-scale studies of invasion are unlikely to increase or conserve biodiversity across large landscapes. Rather, processes that generate landscape heterogeneity—like pyric herbivory—are probably more important for promoting biodiversity across all scales. Scale is a central problem in ecology, and defining scale in management objectives is essential for effective biodiversity conservation

    Macro-nutritional balancing in a circumpolar boreal ruminant under winter conditions

    Get PDF
    Differences in botanical diet compositions among a large number of moose faecal samples collected during winter correlated with the nutritional differences identified in the same samples (Mantel-r = 0.89, p = 0.001), but the nutritional differences were significantly smaller (p  Nutritional geometry revealed that moose mixed Scots pine Pinus sylvestris and Vaccinium spp. as nutritionally complementary foods to reach a nutritional target resembling Salix spp. twigs, and selected for Salix spp. browse (Jacob's D > 0). Available protein (AP) and total non-structural carbohydrates (TNC) were significantly correlated in observed diets but not in hypothetical diets based on food availability. The level of Acetoacetate in moose serum (i.e. ‘starvation’) was weakly negatively associated with digestibility of diets (p = 0.08) and unrelated to increasing AP:TNC and AP:NDF ratios in diets (p > 0.1). Our study is the first to demonstrate complementary feeding in free-ranging moose to attain a nutritional target that has previously been suggested in a feeding trial with captive moose. Our results add support to the hypothesis of nutritional balancing as a driver in the nutritional strategy of moose with implications for both the management of moose and food resources. </ol
    • …
    corecore