Comments on "Vortex Glass and Lattice Melting Transitions in a YNi_2B_2C Single Crystal"

Recently, Mun et.al. (Phys. Rev. Lett., 76, 2790 (1996)) have published their results on single crystal YNi_2B_2C, claiming that their experimental observations can be explained in terms of formation of Vortex Glass and Lattice melting. Our experiments, carried out on samples obtained from the SAME source, reveal a much richer phase diagram and span wider regions of experimental parameter space than Mun et. al. that encompasses most of their observations. We speculate that this material has anomalous intrinsic properties and the results cannot be explained by simple models about the flux lattice.Comment: 1 page, LaTeX type, 1 PostScript figure, Uses PRABIB.STY file, 600 dpi PS file available at http://sagar.physics.neu.edu/preprints.html To appear in Physical Review Letter

Environmental Factors Determine Where the Dutch Live: Results From the Netherlands Twin Register

The heritability of the degree of residential area urbanization in twins and their siblings in the Dutch population was examined. The postal code was known for 6879 twins and 2724 siblings registered with the Netherlands Twin Register and born between 1940 and 1983. Using data from Statistics Netherlands (Centraal Bureau voor de Statistiek, 2001), these postal codes could be related to residential area characteristics, including urbanization level. The degree of urbanization was assessed on a 5-point scale: very heavy, heavy, moderate, low and not urbanized. Genetic model-fitting was carried out in three age cohorts: young adults (born 1975 to 1983), adults (born 1965 to 1974) and older adults (born 1940 to 1964). Twin and sibling resemblance in urbanization level was expressed in polychoric correlations. These correlations decreased from the youngest cohort (.66 to .86) to the oldest cohort (.20 to .58). In all 3 age cohorts, genetic factors did not contribute to familial resemblance. The influence of common environment decreased in importance from the young cohort (70% to 83%) to the old cohort (46% to 47%) and was lower in women than in men in all but the oldest age cohort. This study did not replicate Australian findings of a genetic contribution in the older cohorts; common environmental factors and, increasingly with age, unique environmental factors determine where the Dutch live. Future studies in European and other populations will reveal whether these results are specific to the Dutch population

Behaviorism is Not Enough: Better Recommendations Through Listening to Users

Behaviorism is the currently-dominant paradigm for building and evaluating recommender systems. Both the operation and the evaluation of recommender system applications are most often driven by analyzing the behavior of users. In this paper, we argue that listening to what users say — about the items and recommendations they like, the control they wish to exert on the output, and the ways in which they perceive the system — and not just observing what they do will enable important developments in the future of recommender systems. We provide both philosophical and pragmatic motivations for this idea, describe the various points in the recommendation and evaluation processes where explicit user input may be considered, and discuss benefits that may result from considered incorporation of user preferences at each of these points. In particular, we envision recommender applications that aim to support users’ better selves: helping them live the life that they desire to lead. For example, recommender-assisted behavior change requires algorithms to predict not what users choose or do now, inferable from behavioral data, but what they should choose or do in the future to become healthier, fitter, more sustainable, or culturally aware. We hope that our work will spur useful discussion and many new ideas for recommenders that empower their users

Cellular and mucosal immune reactions to mental and cold stress: Associations with gender and cardiovascular reactivity

To examine gender differences in immune reactions to stress and relationships between immune and cardiovascular reactivity, measures of cellular and mucosal immunity and cardiovascular activity were recorded in 77 men and 78 women at rest and in response to active (mental arithmetic) and passive (cold pressor) stress tasks. Both tasks reduced CD4+ T cells and the CD4/8 ratio. Total lymphocytes, NK cells, CD8+ T cells, and secretory immunoglobulin A (sIgA) increased with active stress. Passive stress decreased sIgA. At rest, men had more NK cells, less CD4+ T cells, and fewer neutrophils than women. Mental stress increased sIgA in men but not women. Cardiovascular reactivity to active stress was associated with increases in NK cells. The data support the hypothesis that stress-related increases in lymphocytes are beta-adrenergically mediated, and suggest that the fall in CD4+ T cells may be alpha-adrenergically driven. Mechanisms underlying sIgA reactions are more difficult to determine. Men and women differed in some cell counts, but not in reactivity, although gender influenced sIgA reactions to arithmetic

Critical State Flux Penetration and Linear Microwave Vortex Response in YBa_2Cu_3O_{7-x} Films

The vortex contribution to the dc field (H) dependent microwave surface impedance Z_s = R_s+iX_s of YBa_2Cu_3O_{7-x} thin films was measured using suspended patterned resonators. Z_s(H) is shown to be a direct measure of the flux density B(H) enabling a very precise test of models of flux penetration. Three regimes of field-dependent behavior were observed: (1) Initial flux penetration occurs on very low field scales H_i(4.2K) 100Oe, (2) At moderate fields the flux penetration into the virgin state is in excellent agreement with calculations based upon the field-induced Bean critical state for thin film geometry, parametrized by a field scale H_s(4.2K) J_c*d 0.5T, (3) for very high fields H >>H_s, the flux density is uniform and the measurements enable direct determination of vortex parameters such as pinning force constants \alpha_p and vortex viscosity \eta. However hysteresis loops are in disagreement with the thin film Bean model, and instead are governed by the low field scale H_i, rather than by H_s. Geometric barriers are insufficient to account for the observed results.Comment: 20 pages, LaTeX type, Uses REVTeX style files, Submitted to Physical Review B, 600 dpi PostScript file with high resolution figures available at http://sagar.physics.neu.edu/preprints.htm

Results and long-term patient satisfaction after gluteal augmentation with platelet-rich plasma-enriched autologous fat

BACKGROUND: Buttock augmentation is gaining increasing popularity in aesthetic surgery. The relatively high incidence of complications after silicone implant placement lead to the increased use of lipofilling techniques, yielding variable results with respect to graft take rate and long-term stability. Platelet-rich plasma (PRP) has been shown to have beneficial effects on wound healing and angiogenesis in the past. Therefore, we aimed at investigating the long-term results and patient satisfaction after PRP-enriched lipofilling for buttock augmentation. METHODS: Twenty-four bilateral gluteal augmentations with PRP-enriched autologous fat were performed. Additionally, contour shaping was achieved by liposuction of the adjacent zones. Post-operative results and complications were recorded, and satisfaction with buttock shape was estimated by a patient questionnaire. RESULTS: Mean follow-up time was 44 months, and mean amount of transferred fat was 481 cc for both sides. No seroma or hematoma formation, infection or liponecrosis were reported during the post-operative follow-up. Subjective patient satisfaction in general increased from preoperatively to 3 months postoperatively and declined only slightly in the long-term course. Satisfaction levels in general were specific for each patient. Patient recovery was quick, and the majority of patients returned to work within 10 days after surgery. CONCLUSIONS: PRP-enhanced lipofilling of the buttocks proved to be a safe procedure including a low complication rate and consistent results. However, subjective patient expectations have to be taken into account when choosing the indication. Further large volume studies are needed to elucidate the potential and benefit of PRP in this context. Level of Evidence: Level IV, therapeutic study

Heritability of self-reported asthma and allergy: A study in adult Dutch twins, siblings and parents.

The present study assessed the prevalence of asthma and allergy, and estimated the importance of genetic and environmental influences on asthma and allergy liability and their association. Longitudinal data on self-reported, doctor-diagnosed asthma and allergy were collected in over 14,000 individuals registered with the Netherlands Twin Register. Structural equation modeling was used for univariate and bivariate genetic analyses on data from twins, their siblings, and parents. Results showed no sex, age, and minimal birth cohort effects for asthma prevalence (11.8%). For allergy, prevalence was higher in women (19.8%) than in men (13.9%). Allergy prevalence at ages 22, 23, and 24 years increased from the 1970 to the 1980 birth cohort. The prevalence of allergy, but not of asthma, was higher in nontwin siblings than in twins. No assortative mating was observed. High (broad-sense) heritabilities were found for asthma (75%) and allergy (66%), with evidence for nonadditive genetic effects in asthma. The association between asthma and allergy (correlation = .65) was largely due to common genes (70%). No sex differences in genetic architecture were found. In conclusion, the prevalence of allergy but not of asthma increased in recent years. Individual differences in the liability to asthma, allergy and their co-occurrence are for a large part accounted for by differences in genetic background. Nonadditive gene action is important, which may have consequences for gene hunting strategies

Heritability of Daytime Ambulatory Blood Pressure in an Extended Twin Design.

The present study estimated the genetic influences on ambulatory systolic and diastolic blood pressure, and on hypertensive status derived from ambulatory levels, in a family sample of 535 twins and 257 singleton siblings. This "extended twin design" was used to explicitly test the possibility that results obtained in singleton siblings are different from those obtained in twins. To examine the effects of excluding (medicated) hypertensive subjects, the genetic analyses were first performed under strict exclusion (medication and/or blood pressure > 135/85 mm Hg), then without the medicated subjects, and, finally, without any exclusion. For the latter analysis, the untreated blood pressure values in subjects using antihypertensive medication were estimated by augmenting the observed blood pressure by the published efficacy of the specific antihypertensive medication used. No evidence was found for differential means, variances, or covariances of ambulatory blood pressure in singletons compared with twins. This indicates that estimates of heritability of ambulatory blood pressure from twin studies can be generalized to the singleton population. Heritability of hypertension, defined as a mean daytime blood pressure > 135/85 mm Hg or antihypertensive medication use, was 61%. Genetic contribution to ambulatory blood pressure was highest when all subjects were included (systolic, 44% to 57%; diastolic, 46% to 63%) and lowest under strict exclusion (systolic, 32% to 50%; diastolic, 31% to 55%). We conclude that exclusion of (medicated) hypertensives removes part of the true genetic variance in ambulatory blood pressure