1,243 research outputs found

    Formation of Ultracold Molecules by Merging Optical Tweezers

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    We demonstrate the formation of a single RbCs molecule during the merging of two optical tweezers, one containing a single Rb atom and the other a single Cs atom. Both atoms are initially predominantly in the motional ground states of their respective tweezers. We confirm molecule formation and establish the state of the molecule formed by measuring its binding energy. We find that the probability of molecule formation can be controlled by tuning the confinement of the traps during the merging process, in good agreement with coupled-channel calculations. We show that the conversion efficiency from atoms to molecules using this technique is comparable to magnetoassociation

    The Link Between Everyday Discrimination, Healthcare Utilization, and Health Status Among a National Sample of Women

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    Background: Research has not adequately examined the potential negative effects of perceiving routine discrimination on general healthcare utilization or health status, especially among reproductive-aged women. We sought to evaluate the association between everyday discrimination, health service use, and perceived health among a national sample of women in the United States. Materials and Methods: Data were drawn from the Women's Healthcare Experiences and Preferences survey, a randomly selected, national probability sample of 1078 U.S. women aged 18?55 years. We examined associations between everyday discrimination (via a standardized scale) on frequency of health service utilization and perceived general health status using chi-square and multivariable logistic regression modeling. Results: Compared with women who reported healthcare visits every 3 years or less (reference group), each one-point increase in discrimination score was associated with higher odds of having healthcare visits annually or more often (odds ratio [OR]?=?1.36, confidence interval [95% CI]?=?1.01?1.83). Additionally, each one-point increase in discrimination score was significantly associated with lower odds of having excellent/very good perceived health (OR?=?0.65; 95% CI?=?0.54?0.80). Conclusion: Perceived discrimination was associated with increased exposure to the healthcare setting among this national sample of women. Perceived discrimination was also inversely associated with excellent/very good perceived health status.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140141/1/jwh.2015.5522.pd

    Potentiality in Biology

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    We take the potentialities that are studied in the biological sciences (e.g., totipotency) to be an important subtype of biological dispositions. The goal of this paper is twofold: first, we want to provide a detailed understanding of what biological dispositions are. We claim that two features are essential for dispositions in biology: the importance of the manifestation process and the diversity of conditions that need to be satisfied for the disposition to be manifest. Second, we demonstrate that the concept of a disposition (or potentiality) is a very useful tool for the analysis of the explanatory practice in the biological sciences. On the one hand it allows an in-depth analysis of the nature and diversity of the conditions under which biological systems display specific behaviors. On the other hand the concept of a disposition may serve a unificatory role in the philosophy of the natural sciences since it captures not only the explanatory practice of biology, but of all natural sciences. Towards the end we will briefly come back to the notion of a potentiality in biology

    Acid treatment biasing to C/N, δ13C and δ15N of organic matter: A Molecular insight

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    (DIPPI-C) - Development of Isotopic Proxies for Palaeoenvironmental Interpretation: a Carbon PerspectiveIt is known that acid treatment methods employed to remove inorganic carbon (IC) from sample material prior to analysis for C/N, δ13C and δ15N cause non-linear, unpredictable biasing to the organic matter (OM) fraction. Consequently, measured C/N, δ13C and δ15N have an uncertainty much greater than instrument precision: uncertainties for C/N are reported in the range of 1 – 100, for δ13C in the range of 0.2 – 6.8 ‰ and for δ15N in the range of 0.2 – 1.5 ‰, in both modern and palaeo environmental materials. Brodie et al (2011) extended this investigation to a down-core lake sedimentary archive (Lake Tianyang, South China) and noted the potential for uncertainties to preclude “common” interpretations of the data (e.g., C/N values a s a n OM p rovenance tool; δ 13C as a proxy for changes in C3 and C4 vegetation). It is evident that the size of uncertainty between sample horizons varies considerably implying a differential relative reaction to acid treatment down-core (i.e., as the type, relative amount and physical state of organic and inorganic components change). We are now investigating this biasing at the molecular level by employing 13C-NMR and GCIRMS techniques on a suite of modern and palaeo environmental materials and on a lake sedimentary archive. This will provide an important insight into the effect of acid treatment on organic compounds (i.e. removal from the sample, breakdown of compounds and partial removal) and associated isotopic fractionation. From an improved understanding of the type of compounds most susceptible to alteration/removal during the acid treatment processes it will be possible to consider refinements to the acid pre-treatment process and provide information on the relative down-core changes in those compounds susceptible to change (which we may be able to glean environmental information from).postprintThe 1st DIPPI-C Workshop, Durham, UK., 8-10 May 2012. In Abstract Bok of the 1st DIPPI-C Workshop, 2012, p. 1

    The bashful and the boastful : prestigious leaders and social change in Mesolithic Societies

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    The creation and maintenance of influential leaders and authorities is one of the key themes of archaeological and historical enquiry. However the social dynamics of authorities and leaders in the Mesolithic remains a largely unexplored area of study. The role and influence of authorities can be remarkably different in different situations yet they exist in all societies and in almost all social contexts from playgrounds to parliaments. Here we explore the literature on the dynamics of authority creation, maintenance and contestation in egalitarian societies, and discuss the implications for our interpretation and understanding of the formation of authorities and leaders and changing social relationships within the Mesolithic

    The prognosis of allocentric and egocentric neglect : evidence from clinical scans

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    We contrasted the neuroanatomical substrates of sub-acute and chronic visuospatial deficits associated with different aspects of unilateral neglect using computed tomography scans acquired as part of routine clinical diagnosis. Voxel-wise statistical analyses were conducted on a group of 160 stroke patients scanned at a sub-acute stage. Lesion-deficit relationships were assessed across the whole brain, separately for grey and white matter. We assessed lesions that were associated with behavioural performance (i) at a sub-acute stage (within 3 months of the stroke) and (ii) at a chronic stage (after 9 months post stroke). Allocentric and egocentric neglect symptoms at the sub-acute stage were associated with lesions to dissociated regions within the frontal lobe, amongst other regions. However the frontal lesions were not associated with neglect at the chronic stage. On the other hand, lesions in the angular gyrus were associated with persistent allocentric neglect. In contrast, lesions within the superior temporal gyrus extending into the supramarginal gyrus, as well as lesions within the basal ganglia and insula, were associated with persistent egocentric neglect. Damage within the temporo-parietal junction was associated with both types of neglect at the sub-acute stage and 9 months later. Furthermore, white matter disconnections resulting from damage along the superior longitudinal fasciculus were associated with both types of neglect and critically related to both sub-acute and chronic deficits. Finally, there was a significant difference in the lesion volume between patients who recovered from neglect and patients with chronic deficits. The findings presented provide evidence that (i) the lesion location and lesion size can be used to successfully predict the outcome of neglect based on clinical CT scans, (ii) lesion location alone can serve as a critical predictor for persistent neglect symptoms, (iii) wide spread lesions are associated with neglect symptoms at the sub-acute stage but only some of these are critical for predicting whether neglect will become a chronic disorder and (iv) the severity of behavioural symptoms can be a useful predictor of recovery in the absence of neuroimaging findings on clinical scans. We discuss the implications for understanding the symptoms of the neglect syndrome, the recovery of function and the use of clinical scans to predict outcome

    Insightful Problem Solving in an Asian Elephant

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    The “aha” moment or the sudden arrival of the solution to a problem is a common human experience. Spontaneous problem solving without evident trial and error behavior in humans and other animals has been referred to as insight. Surprisingly, elephants, thought to be highly intelligent, have failed to exhibit insightful problem solving in previous cognitive studies. We tested whether three Asian elephants (Elephas maximus) would use sticks or other objects to obtain food items placed out-of-reach and overhead. Without prior trial and error behavior, a 7-year-old male Asian elephant showed spontaneous problem solving by moving a large plastic cube, on which he then stood, to acquire the food. In further testing he showed behavioral flexibility, using this technique to reach other items and retrieving the cube from various locations to use as a tool to acquire food. In the cube's absence, he generalized this tool utilization technique to other objects and, when given smaller objects, stacked them in an attempt to reach the food. The elephant's overall behavior was consistent with the definition of insightful problem solving. Previous failures to demonstrate this ability in elephants may have resulted not from a lack of cognitive ability but from the presentation of tasks requiring trunk-held sticks as potential tools, thereby interfering with the trunk's use as a sensory organ to locate the targeted food
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