279 research outputs found
Trace Anomaly in Quantum Spacetime Manifold
In this paper we investigate the trace anomaly in a spacetime where single
events are de-localized as a consequence of short distance quantum coordinate
fluctuations. We obtain a modified form of heat kernel asymptotic expansion
which does not suffer from short distance divergences. Calculation of the trace
anomaly is performed using an IR regulator in order to circumvent the absence
of UV infinities. The explicit form of the trace anomaly is presented and the
corresponding 2D Polyakov effective action and energy momentumtensor are
obtained. The vacuum expectation value of the energy momentum tensor in the
Boulware, Hartle-Hawking and Unruh vacua is explicitly calculated in a
(rt)-section of a recently found, noncommutative geometry inspired,
Schwarzschild-like solution of the Einstein equations. The standard short
distance divergences in the vacuum expectation values are regularized in
agreement with the absence of UV infinities removed by quantum coordinate
fluctuations.Comment: 15pages, RevTex, no figures, 1 Tabl
Female Blow Flies As Vertebrate Resource Indicators
Rapid vertebrate diversity evaluation is invaluable for monitoring changing ecosystems worldwide. Wild blow flies naturally recover DNA and chemical signatures from animal carcasses and feces. We demonstrate the power of blow flies as biodiversity monitors through sampling of flies in three environments with varying human influences: Indianapolis, IN and two national parks (the Great Smoky Mountains and Yellowstone). Dissected fly guts underwent vertebrate DNA sequencing (12S and 16S rRNA genes) and fecal metabolite screening. Integrated Nested Laplace Approximation (INLA) was used to determine the most important abiotic factor influencing fly-derived vertebrate richness. In 720âmin total sampling time, 28 vertebrate species were identified, with 42% of flies containing vertebrate resources: 23% DNA, 5% feces, and 14% contained both. The species of blow fly used was not important for vertebrate DNA recovery, however the use of female flies versus male flies directly influenced DNA detection. Temperature was statistically relevant across environments in maximizing vertebrate detection (meanâ=â0.098, sdâ=â0.048). This method will empower ecologists to test vertebrate community ecology theories previously out of reach due practical challenges associated with traditional sampling
Feynman Path Integral on the Noncommutative Plane
We formulate Feynman path integral on a non commutative plane using coherent
states. The propagator for a free particle exhibits UV cut-off induced by the
parameter of non commutativity.Comment: 7pages, latex 2e, no figures. Accepted for publication on J.Phys.
Some Usability Issues and Research Priorities in Spoken Dialog Applications
Abstract As a priority-setting exercise, we examined interactions between users and a simple spoken dialog system in comparison to interactions with a human operator. Based on the differences seen we propose seven priority issues for research
UV divergence-free QFT on noncommutative plane
We formulate Noncommutative Qauntum Field Theory in terms of fields defined
as mean value over coherent states of the noncommutative plane. No *-product is
needed in this formulation and noncommutativity is carried by a modified
Fourier transform of fields. As a result the theory is UV finite and the cutoff
is provided by the noncommutative parameter theta.Comment: 6 pages, Latex, no figures. Accepted for publication in J.Phys.A. New
references adde
Asia-Pacific ICEMR: Understanding Malaria Transmission to Accelerate Malaria Elimination in the Asia Pacific Region
Gaining an in-depth understanding of malaria transmission requires integrated, multifaceted research approaches. The Asia-Pacific International Center of Excellence in Malaria Research (ICEMR) is applying specifically developed molecular and immunological assays, in-depth entomological assessments, and advanced statistical and mathematical modeling approaches to a rich series of longitudinal cohort and cross-sectional studies in Papua New Guinea and Cambodia. This is revealing both the essential contribution of forest-based transmission and the particular challenges posed by Plasmodium vivax to malaria elimination in Cambodia. In Papua New Guinea, these studies document the complex hostâvectorâparasite interactions that are underlying both the stunning reductions in malaria burden from 2006 to 2014 and the significant resurgence in transmission in 2016 to 2018. Here we describe the novel analytical, surveillance, molecular, and immunological tools that are being applied in our ongoing Asia-Pacific ICEMR research program
Prokineticin Receptor-1 Signaling Inhibits Dose- and Time-Dependent Anthracycline-Induced Cardiovascular Toxicity Via Myocardial and Vascular Protection
Abstract Background High prevalence of heart failure during and following cancer treatments remains a subject of intense research and therapeutic interest. Objectives This study investigated how different concentrations of doxorubicin (DOX) can affect the function of the cardiac cells. This study also examined whether activation of prokineticin receptor-1 (PKR1) by a nonpeptide agonist, IS20, prevents DOX-induced cardiovascular toxicity in mouse models. Methods We used cultured cardiomyocytes, endothelial cells (ECs), and epicardium-derived progenitor cells (EPDCs) for in vitro, assays and tumor-bearing and acute and chronic toxicity mouse models for in vivo assays. Results Brief exposure to cardiomyocytes with high-dose DOX increases the accumulation of reactive oxygen species (ROS) by inhibiting a detoxification mechanism via stabilization of cytoplasmic NRF2. Prolonged exposure to medium-dose DOX induces apoptosis in cardiomyocytes, ECs, and EPDCs. However, low-dose DOX promotes functional defects without inducing apoptosis in EPDCs and ECs. IS20 alleviates detrimental effects of DOX in cardiac cells via activating AKT or mitogen-activated protein kinase pathways. Genetic or pharmacological inactivation of PKR1 subdues these effects of IS20. In a chronic mouse model of DOX cardiotoxicity, IS20 normalizes an elevated serum marker of cardiotoxicity and vascular and EPDC deficits, attenuates apoptosis and fibrosis, and improves the survival rate and cardiac function. IS20 does not interfere with the cytotoxicity or antitumor effects of DOX in breast cancer lines or in a mouse model of breast cancer but attenuates the decreases in LV diastolic volume induced by acute DOX treatment. Conclusions This study identifies the molecular and cellular signature of dose-dependent DOX-mediated cardiotoxicity and provides evidence that PKR1 is a promising target to combat cardiotoxicity of cancer treatments
The Carnegie Supernova Project I: photometry data release of low-redshift stripped-envelope supernovae
The first phase of the Carnegie Supernova Project (CSP-I) was a dedicated
supernova follow-up program based at the Las Campanas Observatory that
collected science data of young, low-redshift supernovae between 2004 and 2009.
Presented in this paper is the CSP-I photometric data release of low-redshift
stripped-envelope core-collapse supernovae. The data consist of optical
(uBgVri) photometry of 34 objects, with a subset of 26 having near-infrared
(YJH) photometry. Twenty objects have optical pre-maximum coverage with a
subset of 12 beginning at least five days prior to the epoch of B-band maximum
brightness. In the near-infrared, 17 objects have pre-maximum observations with
a subset of 14 beginning at least five days prior to the epoch of J-band
maximum brightness. Analysis of this photometric data release is presented in
companion papers focusing on techniques to estimate host-galaxy extinction
(Stritzinger et al., submitted) and the light-curve and progenitor star
properties of the sample (Taddia et al., submitted). The analysis of an
accompanying visual-wavelength spectroscopy sample of ~150 spectra will be the
subject of a future paper.Comment: Updated a couple of small error
Insect chemical ecology: chemically mediated interactions and novel applications in agriculture
Forum PaperInsect chemical ecology (ICE) evolved as a discipline concerned with plantâinsect interactions, and also with a strong
focus on intraspecific pheromone-mediated communication. Progress in this field has rendered a more complete picture of
how insects exploit chemical information in their surroundings in order to survive and navigate their world successfully.
Simultaneously, this progress has prompted new research questions about the evolution of insect chemosensation and related
ecological adaptations, molecular mechanisms that mediate commonly observed behaviors, and the consequences of chemically
mediated interactions in different ecosystems. Themed meetings, workshops, and summer schools are ideal platforms
for discussing scientific advancements as well as identifying gaps and challenges within the discipline. From the 11th to the
22nd of June 2018, the 11th annual PhD course in ICE was held at the Swedish University of Agricultural Sciences (SLU)
Alnarp, Sweden. The course was made up of 35 student participants from 22 nationalities (Fig. 1a) as well as 32 lecturers.
Lectures and laboratory demonstrations were supported by literature seminars, and four broad research areas were covered:
(1) multitrophic interactions and plant defenses, (2) chemical communication focusing on odor sensing, processing, and
behavior, (3) disease vectors, and (4) applied aspects of basic ICE research in agriculture. This particular article contains a
summary and brief synthesis of these main emergent themes and discussions from the ICE 2018 course. In addition, we also
provide suggestions on teaching the next generation of ICE scientists, especially during unprecedented global situationsinfo:eu-repo/semantics/publishedVersio
Heterosexual oral and anal sex in Kinshasa (D.R.Congo): Data from OKAPI prospective cohort
Background
Sexually transmitted infections can be spread through oral and anal heterosexual sex. There are few data on these practices in Sub-Saharan Africa. We analyzed the prevalence of heterosexual oral and anal sex among HIV Voluntary Counseling and Testing (VCT) attendees in Kinshasa and the associated sociodemographics, perceptions and behavioral factors.
Methods
OKAPI (Observational Kinshasa AIDS Prevention Initiative) prospective cohort study. It evaluates the VCT impact on HIV-related knowledge and behaviors at 6 and 12-month follow-up. Since April 2016 until April 2018, 797 persons aged 15â59 years were HIV tested and replied to a baseline interview, including information about anal and oral sex. Descriptive, bi- and multivariate analyses were performed using baseline data.
Results
Among 718 sexually active participants reporting heterosexual sex, 59% had had oral sex, 22% anal sex and 18% both practices. Among participants reporting ânotâ having had sex, 6% reported oral sex, 3% anal sex and 1% both. Oral sex was associated with a daily use of the Internet/mobile phone, perceiving low community HIV risk, reporting HIV-related behaviors (multiple partners, inconsistent condom use, anal, paid and forced sex) and having been pregnant. Being married-monogamous was inversely associated with oral sex. Anal sex was directly associated with having other risk sexual behaviors.
Conclusions
Oral and anal sex were common among people reporting heterosexual sex in Kinshasa. Perceiving a low community HIV risk and having other sexual risk behaviors are associated with these practices, which are commonly not considered as risky despite their strong association with HIV/STIs. They need to be considered when designing preventive strategies in Kinshasa
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