Experimental observation of the 'Tilting Mode' of an array of vortices in a dilute Bose-Einstein Condensate

We have measured the precession frequency of a vortex lattice in a Bose-Einstein condensate of 87Rb atoms. The observed mode corresponds to a collective motion in which all the vortices in the array are tilted by a small angle with respect to the z-axis (the symmetry axis of the trapping potential) and synchronously rotate about this axis. This motion corresponds to excitation of a Kelvin wave along the core of each vortex and we have verified that it has the handedness expected for such helical waves, i.e. precession in the opposite sense to the rotational flow around the vortices. The experimental method used to excite this collective mode closely resembles that used to study the scissors mode and excitation of the scissors mode for a condensate containing a vortex array was used to determine the angular momentum of the system. Indeed, the collective tilting of the array that we have observed has previously been referred to as an `anomalous' scissors mode.Comment: 5 pages, 7 figures to be published in PR

‘Elite’ and ‘Excellence’ from the perspective of young people and their peers

info:eu-repo/semantics/acceptedVersio

Antioxidant Feeding Does Not Impact Incidence or Severity of Liver Abscesses

Liver abscesses are a large source of economic loss in feedlot cattle. Not only do liver abscesses lead to a decrease in feedlot performance, but these livers are condemned in the abattoir and can also lead to a further decrease in carcass value due to trim loss. Tylosin phosphate is a metaphylactic macrolide drug that effectively decreases the occurrence of liver abscesses. The drug is approved by the Food and Drug Administration for over-the-counter use. However, in January 2017 the FDA will require a veterinary feed directive for medically important antibiotics (antibiotics that are used in human health) used in production animal feed. Macrolides are one class of antibiotic that will require a veterinary feed directive. A drug that is accompanied by a veterinary feed directive will require it to be used within the regulations that the FDA has set for the specific drug. This new directive is to encourage the animal production industry to use less medically important antibiotics. It is therefore important to look at alternatives to control liver abscesses in feedlot cattle. Various studies have shown that α-tocopherol acetate increases the humoral response and that ascorbate increases mononuclear lymphocyte counts. These antioxidants are also known to maintain the integrity and structure of ruminal papillae, thereby inhibiting pathogenic bacteria that lead to the formation of liver abscesses from gaining access to the portal blood and then eventually the liver. The objective of this study was to evaluate the impact of antioxidants on feedlot performance, carcass characteristics, and incidence and severity of liver abscesses in finishing heifers

The Genetic and Environmental Sources of Resemblance Between Normative Personality and Personality Disorder Traits

Recent work has suggested a high level of congruence between normative personality, most typically represented by the big five factors, and abnormal personality traits. In 2,293 Norwegian adult twins ascertained from a population-based registry, the authors evaluated the degree of sharing of genetic and environmental influences on normative personality, assessed by the Big Five Inventory (BFI), and personality disorder traits (PDTs), assessed by the Personality Inventory for DSM-S-Norwegian Brief Form (PID-5NBF). For four of the five BFI dimensions, the strongest genetic correlation was observed with the expected PID-5-NBF dimension (e.g., neuroticism with negative affectivity [+], conscientiousness with disinhibition [-]). However, neuroticism, conscientiousness, and agreeableness had substantial genetic correlations with other PID-S-NBF dimensions (e.g., neuroticism with compulsivity [+], agreeableness with detachment [-]). Openness had no substantial genetic correlations with any PID-5-NBF dimension. The proportion of genetic risk factors shared in aggregate between the BFI traits and the PID-5-NBF dimensions was quite high for conscientiousness and neuroticism, relatively robust for extraversion and agreeableness, but quite low for openness. Of the six PID-S-NBF dimensions, three (negative affectivity, detachment, and disinhibition) shared, in aggregate, most of their genetic risk factors with normative personality traits. Genetic factors underlying psychoticism, antagonism, and compulsivity were shared to a lesser extent, suggesting that they are influenced by etiological factors not well indexed by the BFI

Attribution and Categorization Effects in the Representation of Gender Stereotypes

Social stereotypes involve judgments of how typical certain personality traits are of a group. According to the attribution hypothesis, judgments of trait typicality depend on the perceived prevalence of the trait in the target group. According to the categorization hypothesis, such judgments depend on the degree to which a trait is thought to be more or less prevalent in the target group than in a relevant comparison group. A study conducted with women and men as target groups showed that the attribution hypothesis fit the data best when typicality ratings were made in an absolute format. When, however, typicality ratings were made in a comparative format (how typical is the trait of women as compared with men?), both hypotheses received support. Analytical derivation, supported by empirical evidence, showed an inverse relationship between the size of perceived group differences and their weight given in stereotyping. Implications for stereotype measurement and the rationality of social perception are discussed

Maintaining human wellbeing as socio-environmental systems undergo regime shifts

Global environmental change is pushing many socio-environmental systems towards critical thresholds, where ecological systems' states are on the precipice of tipping points and interventions are needed to navigate or avert impending transitions. Flickering, where a system vacillates between alternative stable states, is touted as a useful early warning signal of irreversible transitions to undesirable ecological regimes. However, while flickering may presage an ecological tipping point, these dynamics also pose unique challenges for human adaptation. In this work, we link an ecological model that can exhibit flickering to a model of human adaptation to a changing environment. This allows us to explore the impact of flickering on the utility of adaptive agents in a coupled socio-environmental system. We highlight the conditions under which flickering causes wellbeing to decline disproportionately, and explore how these dynamics impact the optimal timing of a transformational change that partially decouples wellbeing from environmental variability. The implications of flickering on nomadic communities in Mongolia, artisanal fisheries, and wildfire systems are explored as possible case studies. Flickering, driven in part by climate change and changes to governance systems, may already be impacting communities. We argue that governance interventions investing in adaptive capacity could blunt the negative impact of flickering that can occur as socio-environmental systems pass through tipping points, and therefore contribute to the sustainability of these systems

Surface-induced charge state conversion of nitrogen-vacancy defects in nanodiamonds

We present a study of the charge state conversion of single nitrogen-vacancy (NV) defects hosted in nanodiamonds (NDs). We first show that the proportion of negatively-charged NV$^{-}$ defects, with respect to its neutral counterpart NV$^{0}$, decreases with the size of the ND. We then propose a simple model based on a layer of electron traps located at the ND surface which is in good agreement with the recorded statistics. By using thermal oxidation to remove the shell of amorphous carbon around the NDs, we demonstrate a significant increase of the proportion of NV$^{-}$ defects in 10-nm NDs. These results are invaluable for further understanding, control and use of the unique properties of negatively-charged NV defects in diamondComment: 6 pages, 4 figure