1,104 research outputs found
A multiple scales approach to maximal superintegrability
In this paper we present a simple, algorithmic test to establish if a
Hamiltonian system is maximally superintegrable or not. This test is based on a
very simple corollary of a theorem due to Nekhoroshev and on a perturbative
technique called multiple scales method. If the outcome is positive, this test
can be used to suggest maximal superintegrability, whereas when the outcome is
negative it can be used to disprove it. This method can be regarded as a finite
dimensional analog of the multiple scales method as a way to produce soliton
equations. We use this technique to show that the real counterpart of a
mechanical system found by Jules Drach in 1935 is, in general, not maximally
superintegrable. We give some hints on how this approach could be applied to
classify maximally superintegrable systems by presenting a direct proof of the
well-known Bertrand's theorem.Comment: 30 pages, 4 figur
BRST Detour Quantization
We present the BRST cohomologies of a class of constraint (super) Lie
algebras as detour complexes. By giving physical interpretations to the
components of detour complexes as gauge invariances, Bianchi identities and
equations of motion we obtain a large class of new gauge theories. The pivotal
new machinery is a treatment of the ghost Hilbert space designed to manifest
the detour structure. Along with general results, we give details for three of
these theories which correspond to gauge invariant spinning particle models of
totally symmetric, antisymmetric and K\"ahler antisymmetric forms. In
particular, we give details of our recent announcement of a (p,q)-form K\"ahler
electromagnetism. We also discuss how our results generalize to other special
geometries.Comment: 43 pages, LaTeX, added reference
High Temperature Stability of Onion-Like Carbon vs Highly Oriented Pyrolytic Graphite
Abstract
The thermodynamic stability of onion-like carbon (OLC) nanostructures with respect to highly oriented pyrolytic graphite
(HOPG) was determined in the interval 765–1030 K by the electromotive force (emf) measurements of solid electrolyte
galvanic cell: (Low) Pt|Cr3C2,CrF2,OLC|CaF2s.c.|Cr3C2,CrF2,HOPG|Pt (High). The free energy change of transformation
HOPG = OLC was found positive below 920.6 K crossing the zero value at this temperature. Its trend with temperature was
well described by a 3rd degree polynomial. The unexpected too high values of
LDrHT
LT
P
~DcPĂ°TĂž jointly to the HR-TEM,
STEM and EELS evidences that showed OLC completely embedded in rigid cages made of a Cr3C2/CrF2 matrix, suggested
that carbon in the electrodes experienced different internal pressures. This was confirmed by the evaluation under constant
volume of
dP
dT
by the
a
k
ratio for OLC (0.5 MPa K21) and HOPG (8 Pa K21) where a and k are the isobaric thermal expansion
and isothermal compressibility coefficients, respectively. The temperature dependency of the pressure was derived and
utilized to calculate the enthalpy and entropy changes as function of temperature and pressure. The highest value of the
internal pressure experienced by OLC was calculated to be about 7 GPa at the highest temperature. At 920.6 K, DrH and
DrS values are 95.8 kJ mol21 and 104.1 JK21 mol21, respectively. The surface contributions to the energetic of the system
were evaluated and they were found negligible compared with the bulk terms. As a consequence of the high internal
pressure, the values of the enthalpy and entropy changes were mainly attributed to the formation of carbon defects in OLC
considered as multishell fullerenes. The change of the carbon defect fraction is reported as a function of temperature
Pentraxin 3 in cardiovascular disease
The long pentraxin PTX3 is a member of the pentraxin family produced locally by stromal and myeloid cells in response to proinflammatory signals and microbial moieties. The prototype of the pentraxin family is C reactive protein (CRP), a widely-used biomarker in human pathologies with an inflammatory or infectious origin. Data so far describe PTX3 as a multifunctional protein acting as a functional ancestor of antibodies and playing a regulatory role in inflammation. Cardiovascular disease (CVD) is a leading cause of mortality worldwide, and inflammation is crucial in promoting it. Data from animal models indicate that PTX3 can have cardioprotective and atheroprotective roles regulating inflammation. PTX3 has been investigated in several clinical settings as possible biomarker of CVD. Data collected so far indicate that PTX3 plasma levels rise rapidly in acute myocardial infarction, heart failure and cardiac arrest, reflecting the extent of tissue damage and predicting the risk of mortality
Threat of Sexual Disqualification: The Consequences of Erectile Dysfunction and Other Sexual Changes for Gay and Bisexual Men With Prostate Cancer.
Gay and bisexual (GB) men with prostate cancer (PCa) have been described as an "invisible diversity" in PCa research due to their lack of visibility, and absence of identification of their needs. This study examined the meaning and consequences of erectile dysfunction (ED) and other sexual changes in 124Â GB men with PCa and 21 male partners, through an on-line survey. A sub-sample of 46 men with PCa and seven partners also took part in a one-to-one interview. ED was reported by 72Â % of survey respondents, associated with reports of emotional distress, negative impact on gay identities, and feelings of sexual disqualification. Other sexual concerns included loss of libido, climacturia, loss of sensitivity or pain during anal sex, non-ejaculatory orgasms, and reduced penis size. Many of these changes have particular significance in the context of gay sex and gay identities, and can result in feelings of exclusion from a sexual community central to GB men's lives. However, a number of men were reconciled to sexual changes, did not experience a challenge to identity, and engaged in sexual re-negotiation. The nature of GB relationships, wherein many men are single, engage in casual sex, or have concurrent partners, influenced experiences of distress, identity, and renegotiation. It is concluded that researchers and clinicians need to be aware of the meaning and consequences of sexual changes for GB men when designing studies to examine the impact of PCa on men's sexuality, advising GB men of the sexual consequences of PCa, and providing information and support to ameliorate sexual changes
(p,q)-form Kaehler Electromagnetism
We present a gauge invariant generalization of Maxwell's equations and p-form
electromagnetism to Kaehler spacetimes.Comment: 5 pages, LaTe
Local attitudes toward Apennine brown bears: Insights for conservation issues
Human-carnivore coexistence is a multi-faceted issue that requires an understanding of the diverse attitudes and perspectives of the communities living with large carnivores. To inform initiatives that encourage behaviors in line with conservation goals, we focused on assessing the two components of attitudes (i.e., feelings and beliefs), as well as norms of local communities coexisting with Apennine brown bears (Ursus arctos marsicanus) for a long time. This bear population is under serious extinction risks due to its persistently small population size, which is currently confined to the long-established protected area of Abruzzo, Lazio and Molise National Park (PNALM) and its surrounding region in central Italy. We interviewed 1,611 residents in the PNALM to determine attitudes and values toward bears. We found that support for the bear's legal protection was widespread throughout the area, though beliefs about the benefits of conserving bears varied across geographic administrative districts. Our results showed that residents across our study areas liked bears. At the same time, areas that received more benefits from tourism were more strongly associated with positive feelings toward bears. Such findings provide useful information to improve communication efforts of conservation authorities with local communities
Health-Related Quality of Life, Psychological Distress, and Sexual Changes Following Prostate Cancer: A Comparison of Gay and Bisexual Men with Heterosexual Men.
INTRODUCTION: Decrements in health-related quality of life (HRQOL) and sexual difficulties are a recognized consequence of prostate cancer (PCa) treatment. However little is known about the experience of gay and bisexual (GB) men. AIM: HRQOL and psychosexual predictors of HRQOL were examined in GB and heterosexual men with PCa to inform targeted health information and support. METHOD: One hundred twenty-four GB and 225 heterosexual men with PCa completed a range of validated psychosexual instruments. MAIN OUTCOME MEASURE: Functional Assessment of Cancer Therapy-Prostate (FACT-P) was used to measure HRQOL, with validated psychosexual measures, and demographic and treatment variables used as predictors. RESULTS: GB men were significantly younger (64.25 years) than heterosexual men (71.54 years), less likely to be in an ongoing relationship, and more likely to have casual sexual partners. Compared with age-matched population norms, participants in both groups reported significantly lower sexual functioning and HRQOL, increased psychological distress, disruptions to dyadic sexual communication, and lower masculine self-esteem, sexual confidence, and sexual intimacy. In comparison with heterosexual men, GB men reported significantly lower HRQOL (P = .046), masculine self-esteem (P < .001), and satisfaction with treatment (P = .013); higher psychological distress (P = .005), cancer related distress (P < .001) and ejaculatory concern (P < .001); and higher sexual functioning (P < .001) and sexual confidence (P = .001). In regression analysis, psychological distress, cancer-related distress, masculine self-esteem, and satisfaction with treatment were predictors of HRQOL for GB men (R2Adj = .804); psychological distress and sexual confidence were predictors for heterosexual men (R2Adj = .690). CONCLUSION: These findings confirm differences between GB and heterosexual men in the impact of PCa on HRQOL across a range of domains, suggesting there is a need for GB targeted PCa information and support, to address the concerns of this "hidden population" in PCa care
Osteopontin as Candidate Biomarker of Coronary Disease despite Low Cardiovascular Risk: Insights from CAPIRE Study
Stratification according high cardiovascular (CV) risk categories, still represents a clinical challenge. In this analysis of the CAPIRE study (NCT02157662), we investigate whether inflammation could fit between CV risk factors (RFs) and the presence of coronary artery disease (CAD). In total, 544 patients were included and categorized according with the presence of CAD and CV risk factor burden (low/multiple). The primary endpoint was to verify any independent association of neutrophil-related biomarkers with CAD across CV risk categories. The highest values of osteo-pontin (OPN) were detected in the low RF group and associated with CAD (23.2 vs. 19.4 ng/mL; p = 0.001), although no correlation with plaque extent and/or composition were observed. Con-versely, myeloperoxidase (MPO) and resistin did not differ by CAD presence. Again, OPN was identified as independent variable associated with CAD but only in the low RF group (adjOR 8.42 [95% CI 8.42\u201346.83]; p-value = 0.015). As an ancillary finding, a correlation linked OPN with the neutrophil degranulation biomarker MPO (r = 0.085; p = 0.048) and resistin (r = 0.177; p = 3.4
7 10 125 ). In the present study, OPN further strengthens its role as biomarker of CAD, potentially bridging subclinical CV risk with development of atherosclerosis
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