4,261 research outputs found
Chern-Simons terms in Noncommutative Geometry and its application to Bilayer Quantum Hall Systems
Considering bilayer systems as extensions of the planar ones by an internal
space of two discrete points, we use the ideas of Noncommutative Geometry to
construct the gauge theories for these systems. After integrating over the
discrete space we find an effective action involving an extra complex
scalar field, which can be interpreted as arising from the tunneling between
the layers. The gauge fields are found in different phases corresponding to the
different correlations due to the Coulomb interaction between the layers. In a
particular phase, when the radial part of the complex scalar field is a
constant, we recover the Wen-Zee model of Bilayer Quantum Hall systems. There
are some circumstances, where this radial part may become dynamical and cause
dissipation in the oscillating supercurrent between the layers.Comment: 17 pages, more explanations have been added to make our points
clearer compared with the previous densed versio
A measurement of the attenuation of radiation from F-18 by a PET/MR scanner
This is the peer reviewed version of the following article: Wendt, R.E., III, Ai, H.A., Meier, J.G., Lopez, B.P., Fahrenholtz, S.J. and Mawlawi, O.R. (2018), A measurement of the attenuation of radiation from F-18 by a PET/MR scanner. J Appl Clin Med Phys, 19: 336-340. , which has been published in final form at https://doi.org/10.1002/acm2.12479. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.https://openworks.mdanderson.org/mdacc_imgphys_pubs/1004/thumbnail.jp
Associations between sexual activity and weight status: Findings from the English Longitudinal Study of Ageing.
OBJECTIVE: To investigate the association between weight status and sexual activity in middle-aged and older adults. METHODS: Cross-sectional analysis on Wave 6 (2012/13) of the English Longitudinal Study of Ageing. Data were from 2,200 men and 2,737 women aged ≥50 years (mean 68.2 years). The explanatory variable was weight status, defined as normal-weight (BMI: ≤24.9), overweight (BMI: 25.0-29.9) or obese (BMI: ≥30) based on objective measurements of height and weight. Outcome variables were any self-reported sexual activity in the last year (yes/no) and, if yes, frequency of sexual intercourse in the last month. Covariates included a range of sociodemographic, lifestyle, and health-related variables. Associations were analysed using binary (past-year sexual activity) and ordinal (frequency of past-month sexual intercourse) logistic regression models. RESULTS: The majority (73.3%) of men and half (50.0%) of women reported any sexual activity in the last year. The odds of reporting any sexual activity in the last year did not differ significantly by weight status in either men or women. However, among those who were sexually active, men with overweight (OR = 1.45, 95% CI 1.15-1.81, p = 0.002) or obesity (OR = 1.38, 95% CI 1.07-1.77, p = 0.015), and women with overweight (OR = 1.34, 95% CI 1.05-1.71, p = 0.017) reported significantly more frequent sexual intercourse in the last month compared with those who had a BMI in the normal-weight range, after adjustment for covariates. CONCLUSION: Older adults with overweight or obesity who are sexually active engage in more frequent sexual activity than those who are normal weight
Effect of a Saline Nutritional Regime on Tomato Fruit Yield and on Enhancement of Fruit Quality
The effect of a saline nutritional regime on tomato (Lycopersicon esculentum Mill.) fruit yield and fruit quality enhancement for five cultivars (CLN 425, Pearson, Napoli, Hymar, and Sierra) was studied. The saline nutrient treatment consisted of (i) a control. Hoagland's solution (EC=2.5 mScm -1), (ii) Hoagland's solution + 50 mM NaCl (EC=7.46 mScm-1), (iii) Hoagland's solution + 50 mM NaCl + 4 mM K2SO4 + 2 mM H3PO4 (EC=8.31mScm-1), (iv) same as in (iii)3 but applied when plants were at 50% flowering, then the plants were irrigated with Hoagland’s solution as in the control, and (v) same as in (iii) until the plans were at 5096 flowering, thereafter NaCl concentration was reduced to 25mM (EC=5.87 mscm-1). Plans were seven weeks old at the start of the saline treatments. Each plant was in PVC cylindrical pots (15 cm diameter and 27 cm height) containing washed quartz sand. Fruits were harvested once weekly for ten weeks at incipient red. The control gave a higher fruit yield than the saline treatments. However, the tomato fruits from thesaline treatments had higher titratable acidity, higher total soluble solids, and higher total solid indicating better quality of the fruits than those from the control. Of the five cultivars studied, Hymar had the highest fruit yield followed by Pearson. Hymar’s quality was also highest, followed by CLN 425. Napoli was the most susceptible to salinity and Sierra had the lowest quality
Measurements and analysis of large-scale fading characteristics in curved subway tunnels at 920 MHz, 2400 MHz, and 5705 MHz
ave propagation characteristics in curved tunnels are of importance for designing reliable communications in subway systems. This paper presents the extensive propagation measurements conducted in two typical types of subway tunnels—traditional arched “Type I” tunnel and modern arched “Type II” tunnel—with300- and 500-m radii of curvature with different configurations—horizontal and vertical polarizations at 920, 2400, and 5705 MHz, respectively. Based on the measurements, statistical metrics of propagation loss and shadow fading (path-loss exponent, shadow fading distribution, autocorrelation, and cross-correlation) in all the measurement cases are extracted. Then, the large-scale fading characteristics in the curved subway tunnels are compared with the cases of road and railway tunnels, the other main rail traffic scenarios, and some “typical” scenarios to give a comprehensive insight into the propagation in various scenarios where the intelligent transportation systems are deployed. Moreover, for each of the large-scale fading parameters, extensive analysis and discussions are made to reflect the physical laws behind the observations. The quantitative results and findings are useful to realize intelligent transportation systems in the subway system
Association of VAV2 and VAV3 polymorphisms with cardiovascular risk factors
Hypertension, diabetes and obesity are cardiovascular risk factors closely associated to the development of renal and cardiovascular target organ damage. VAV2 and VAV3, members of the VAV family proto-oncogenes, are guanosine nucleotide exchange factors for the Rho and Rac GTPase family, which is related with cardiovascular homeostasis. We have analyzed the relationship between the presence of VAV2 rs602990 and VAV3 rs7528153 polymorphisms with cardiovascular risk factors and target organ damage (heart, vessels and kidney) in 411 subjects. Our results show that being carrier of the T allele in VAV2 rs602990 polymorphism is associated with an increased risk of obesity, reduced levels of ankle-brachial index and diastolic blood pressure and reduced retinal artery caliber. In addition, being carrier of T allele is associated with increased risk of target organ damage in males. On the other hand, being carrier of the T allele in VAV3 rs7528153 polymorphism is associated with a decreased susceptibility of developing a pathologic state composed by the presence of hypertension, diabetes, obesity or cardiovascular damage, and with an increased risk of developing altered basal glycaemia. This is the first report showing an association between VAV2 and VAV3 polymorphisms with cardiovascular risk factors and target organ damage
Functional and molecular characterization of inherited platelet disorders in the Iberian Peninsula: results from a collaborative study
BACKGROUND:
The diagnostic evaluation of inherited platelet disorders (IPDs) is complicated and time-consuming, resulting in a relevant number of undiagnosed and incorrectly classified patients. In order to evaluate the spectrum of IPDs in individuals with clinical suspicion of these disorders, and to provide a diagnostic tool to centers not having access to specific platelets studies, we established the project "Functional and Molecular Characterization of Patients with Inherited Platelet Disorders" under the scientific sponsorship of the Spanish Society of Thrombosis and Haemostasis.
PATIENTS/METHODS:
Subjects were patients from a prospective cohort of individuals referred for clinical suspicion of IPDs as well as healthy controls. Functional studies included light transmission aggregation, flow cytometry, and when indicated, Western-blot analysis of platelet glycoproteins, and clot retraction analysis. Genetic analysis was mainly performed by sequencing of coding regions and proximal regulatory regions of the genes of interest.
RESULTS:
Of the 70 cases referred for study, we functionally and molecularly characterized 12 patients with Glanzmann Thrombasthenia, 8 patients with Bernard Soulier syndrome, and 8 with other forms of IPDs. Twelve novel mutations were identified among these patients. The systematic study of patients revealed that almost one-third of patients had been previously misdiagnosed.
CONCLUSIONS:
Our study provides a global picture of the current limitations and access to the diagnosis of IPDs, identifies and confirms new genetic variants that cause these disorders, and emphasizes the need of creating reference centers that can help health care providers in the recognition of these defects
The luminosity function of field galaxies
Schmidt's method for construction of luminosity function of galaxies is
generalized by taking into account the dependence of density of galaxies from
the distance in the near Universe. The logarithmical luminosity function (LLF)
of field galaxies depending on morphological type is constructed. We show that
the LLF for all galaxies, and also separately for elliptical and lenticular
galaxies can be presented by Schechter function in narrow area of absolute
magnitudes. The LLF of spiral galaxies was presented by Schechter function for
enough wide area of absolute magnitudes: . Spiral galaxies differ slightly by
parameter . At transition from early spirals to the late spirals parameter in
Schechter function is reduced. The reduction of mean luminosity of galaxies is
observed at transition from elliptical galaxies to lenticular galaxies, to
early spiral galaxies, and further, to late spiral galaxies, in a bright end, .
The completeness and the average density of samples of galaxies of different
morphological types are estimated. In the range the mean number density of all
galaxies is equal 0.127 Mpc-3.Comment: 14 page, 8 figures, to appear in Astrophysic
Cognitive appraisal of environmental stimuli induces emotion-like states in fish
The occurrence of emotions in non-human animals has been the focus of debate over the years. Recently, an interest in expanding this debate to non-tetrapod vertebrates and to invertebrates has emerged. Within vertebrates, the study of emotion in teleosts is particularly interesting since they represent a divergent evolutionary radiation from that of tetrapods, and thus they provide an insight into the evolution of the biological mechanisms of emotion. We report that Sea Bream exposed to stimuli that vary according to valence (positive, negative) and salience (predictable, unpredictable) exhibit different behavioural, physiological and neuromolecular states. Since according to the dimensional theory of emotion valence and salience define a two-dimensional affective space, our data can be interpreted as evidence for the occurrence of distinctive affective states in fish corresponding to each the four quadrants of the core affective space. Moreover, the fact that the same stimuli presented in a predictable vs. unpredictable way elicited different behavioural, physiological and neuromolecular states, suggests that stimulus appraisal by the individual, rather than an intrinsic characteristic of the stimulus, has triggered the observed responses. Therefore, our data supports the occurrence of emotion-like states in fish that are regulated by the individual's perception of environmental stimuli.European Commission [265957 Copewell]; Fundacao para a Ciencia e Tecnologia [SFRH/BD/80029/2011, SFRH/BPD/72952/2010]info:eu-repo/semantics/publishedVersio
Discovery of the first dual GSK3 beta inhibitor/Nrf2 inducer. A new multitarget therapeutic strategy for Alzheimer's disease
The formation of neurofibrillary tangles (NFTs), oxidative stress and neuroinflammation have emerged as key targets for the treatment of Alzheimer’s disease (AD), the most prevalent neurodegenerative disorder. These pathological hallmarks are closely related to the over-activity of the enzyme GSK3β and the downregulation of the defense pathway Nrf2-EpRE observed in AD patients. Herein, we report the synthesis and pharmacological evaluation of a new family of multitarget 2,4-dihydropyrano[2,3-c]pyrazoles as dual GSK3β inhibitors and Nrf2 inducers. These compounds are able to inhibit GSK3β and induce the Nrf2 phase II antioxidant and anti-inflammatory pathway at micromolar concentrations, showing interesting structure-activity relationships. The association of both activities has resulted in a remarkable anti-inflammatory ability with an interesting neuroprotective profile on in vitro models of neuronal death induced by oxidative stress and energy depletion and AD. Furthermore, none of the compounds exhibited in vitro neurotoxicity or hepatotoxicity and hence they had improved safety profiles compared to the known electrophilic Nrf2 inducers. In conclusion, the combination of both activities in this family of multitarget compounds confers them a notable interest for the development of lead compounds for the treatment of AD
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