607 research outputs found
Tsallis holographic dark energy under Complex form of Quintessence model
In this paper, we use a Tsallis holographic dark energy model in two forms,
interacting and non-interacting cases, to acquire some parameters as the
equation of state for the energy density of the Tsallis model in the FRW
universe concerning the complex form of quintessence model. We will study the
cosmology of complex quintessence by revamping the potential and investigating
the scalar field dynamics. Then we analyze () and stability in
two cases, i.e., non-interacting and interacting. We will explore whether these
cases describe a real universe by calculating fractional energy density
and concerning two parts of the quintessence field effect (
complex and real part ) by considering the real part of this field to be a
slow-roll field. We know that the part in which the fractional energy density
() does not describe a real universe. Also, we specified an
interacting coupling parameter that depends on the constant parameter
of the Tsallis holographic model () with respect to fractional energy
density (). Unlike independence between the fractional energy density and
interacting coupling in the real quintessence model, we determine a
relationship among these parameters in this theory. Finally, by plotting some
figures, we specify the features of () and () in
two cases and compare the result with each other.Comment: 22 pages, 4 figures, Accepted for publication in Communications in
Theoretical Physic
Photoluminescence studies of individual and few GaSb/GaAs quantum rings
We present optical studies of individual and few GaSb quantum rings embedded in a GaAs matrix. Contrary to expectation for type-II confinement, we measure rich spectra containing sharp lines. These lines originate from excitonic recombination and are observed to have resolution-limited full-width at half maximum of 200 µeV. The detail provided by these measurements allows the characteristic type-II blueshift, observed with increasing excitation power, to be studied at the level of individual nanostructures. These findings are in agreement with hole-charging being the origin of the observed blueshif
The evolving landscape of sea-level rise science from 1990 to 2021
As sea-level rise (SLR) accelerates due to climate change, its multidisciplinary field of science has similarly expanded, from 41 articles published in 1990 to 1475 articles published in 2021, and nearly 15,000 articles published in the Web of Science over this 32-year period. Here, big-data bibliometric techniques are adopted to systematically analyse this large literature set. Four main research clusters (themes) emerge: (I) geological dimensions and sea-level indicators, (II) impacts, risks, and adaptation, (III) physical components of sea-level change, and (IV) coastal ecosystems and habitats, with 16 associated sub-themes. This analysis provides insights into the evolution of research agendas, the challenges and opportunities for future assessments (e.g. next IPCC reports), and growing focus on adaptation. For example, the relative importance of sub-themes evolves consistently with a relative decline in pure science analysis towards solution-focused topics associated with SLR risks such as high-end rises, declining ecosystem services, flood hazards, and coastal erosion/squeeze
The Green Bank North Celestial Cap Pulsar Survey. IV: Four New Timing Solutions
We present timing solutions for four pulsars discovered in the Green Bank
Northern Celestial Cap (GBNCC) survey. All four pulsars are isolated with spin
periods between 0.26s and 1.84s. PSR J00382501 has a 0.26s
period and a period derivative of ,
which is unusually low for isolated pulsars with similar periods. This low
period derivative may be simply an extreme value for an isolated pulsar or it
could indicate an unusual evolution path for PSR J00382501, such as a
disrupted recycled pulsar (DRP) from a binary system or an orphaned central
compact object (CCO). Correcting the observed spin-down rate for the Shklovskii
effect suggests that this pulsar may have an unusually low space velocity,
which is consistent with expectations for DRPs. There is no X-ray emission
detected from PSR J00382501 in an archival swift observation, which suggests
that it is not a young orphaned CCO. The high dispersion measure of PSR
J1949+3426 suggests a distance of 12.3kpc. This distance indicates that PSR
J1949+3426 is among the most distant 7% of Galactic field pulsars, and is one
of the most luminous pulsars.Comment: 7 pages, 5 figure
The HepHIV 2023 Madrid conference: A call to action for political leadership in reaching the sustainable development goals on earlier testing and linkage to care for HIV, viral hepatitis, and sexually transmitted infections
Introduction and Objectives: The HepHIV 2023 Conference, held in Madrid in November 2023, highlighted how Europe is not on track to meet the United Nations (UN) sustainable development goals and Joint UN Programme on HIV/AIDS (UNAIDS) targets. This article presents the outcomes of the conference, which focus on ways to improve testing and linkage to care for HIV, viral hepatitis, and other sexually transmitted infections. HIV-related stigma and discrimination, a major barrier to progress, was a key concept of the conference and on the agenda of the Spanish Presidency of the European Union. Methods: The HepHIV 2023 organizing committee, alongside the Spanish Ministry of Health, oversaw the conference organization and prepared the scientific programme based on abstract rankings. Key outcomes are derived from conference presentations and discussions. Results: Conference presentations covered the obstacles that HIV-related stigma and discrimination continue to pose to access to services, models for data collection to better monitor progress in the future, and examples of legislative action that can be taken at national levels. Diversification of testing approaches was also highlighted, to reach key populations, (e.g. migrant populations), to increase testing offered in healthcare settings (e.g. emergency departments), and to account for different stages of epidemics across the region. Conclusion: With a strong call for intensified action to address the impact of HIV-related stigma and discrimination on testing uptake, the conference concluded that strengthened collaboration is required between governments and implementers around testing and linkage to care. There is also an ongoing need to ensure sustainable political commitment and appropriate resource allocation to address gaps and inequalities in access for key populations and to focus on the implementation of integrated responses to HIV, viral hepatitis, and sexually transmitted infections. © 2024 The Author(s). HIV Medicine published by John Wiley & Sons Ltd on behalf of British HIV Association
Strategic foresight: towards enhancing leadership capabilities and business sustainability
СЕКЦИЯ 9. АКТУАЛЬНЫЕ ФИНАНСОВЫЕ И ЭКОНОМИЧЕСКИЕ АСПЕКТЫ
РАЗВИТИЯ ОТРАСЛЕ
Prognostic and Mechanistic Potential of Progesterone Sulfates in Intrahepatic Cholestasis of Pregnancy and Pruritus Gravidarum
A challenge in obstetrics is to distinguish pathological symptoms from those associated with normal changes of pregnancy, typified by the need to differentiate whether gestational pruritus of the skin is an early symptom of intrahepatic cholestasis of pregnancy (ICP) or due to benign pruritus gravidarum. ICP is characterized by raised serum bile acids and complicated by spontaneous preterm labor and stillbirth. A biomarker for ICP would be invaluable for early diagnosis and treatment and to enable its differentiation from other maternal diseases. Three progesterone sulfate compounds, whose concentrations have not previously been studied, were newly synthesized and assayed in the serum of three groups of ICP patients and found to be significantly higher in ICP at 9-15 weeks of gestation and prior to symptom onset (group 1 cases/samples: ICP n = 35/80, uncomplicated pregnancy = 29/100), demonstrating that all three progesterone sulfates are prognostic for ICP. Concentrations of progesterone sulfates were associated with itch severity and, in combination with autotaxin, distinguished pregnant women with itch that would subsequently develop ICP from pruritus gravidarum (group 2: ICP n = 41, pruritus gravidarum n = 14). In a third group of first-trimester samples all progesterone sulfates were significantly elevated in serum from low-risk asymptomatic women who subsequently developed ICP (ICP/uncomplicated pregnancy n = 54/51). Finally, we show mechanistically that progesterone sulfates mediate itch by evoking a Tgr5-dependent scratch response in mice. Conclusion: Our discovery that sulfated progesterone metabolites are a prognostic indicator for ICP will help predict onset of ICP and distinguish it from benign pruritus gravidarum, enabling targeted obstetric care to a high-risk population. Delineation of a progesterone sulfate-TGR5 pruritus axis identifies a therapeutic target for itch management in ICP
Acute maternal infection and risk of pre-eclampsia: a population-based case-control study.
BACKGROUND: Infection in pregnancy may be involved in the aetiology of pre-eclampsia. However, a clear association between acute maternal infection and pre-eclampsia has not been established. We assessed whether acute urinary tract infection, respiratory tract infection, and antibiotic drug prescriptions in pregnancy (a likely proxy for maternal infection) are associated with an increased risk of pre-eclampsia. METHODS AND FINDINGS: We used a matched nested case-control design and data from the UK General Practice Research Database to examine the association between maternal infection and pre-eclampsia. Primiparous women aged at least 13 years and registered with a participating practice between January 1987 and October 2007 were eligible for inclusion. We selected all cases of pre-eclampsia and a random sample of primiparous women without pre-eclampsia (controls). Cases (n=1533) were individually matched with up to ten controls (n=14236) on practice and year of delivery. We calculated odds ratios and 95% confidence intervals for pre-eclampsia comparing women exposed and unexposed to infection using multivariable conditional logistic regression. After adjusting for maternal age, pre-gestational hypertension, diabetes, renal disease and multifetal gestation, the odds of pre-eclampsia were increased in women prescribed antibiotic drugs (adjusted odds ratio 1.28;1.14-1.44) and in women with urinary tract infection (adjusted odds ratio 1.22;1.03-1.45). We found no association with maternal respiratory tract infection (adjusted odds ratio 0.91;0.72-1.16). Further adjustment for maternal smoking and pre-pregnancy body mass index made no difference to our findings. CONCLUSIONS: Women who acquire a urinary infection during pregnancy, but not those who have a respiratory infection, are at an increased risk of pre-eclampsia. Maternal antibiotic prescriptions are also associated with an increased risk. Further research is required to elucidate the underlying mechanism of this association and to determine whether, among women who acquire infections in pregnancy, prompt treatment or prophylaxis against infection might reduce the risk of pre-eclampsia
Mpox vaccination willingness, determinants, and communication needs in gay, bisexual, and other men who have sex with men, in the context of limited vaccine availability in the Netherlands (Dutch Mpox-survey)
IntroductionIn the 2022 multicountry mpox (formerly named monkeypox) outbreak, several countries offered primary preventive vaccination (PPV) to people at higher risk for infection. We study vaccine acceptance and its determinants, to target and tailor public health (communication-) strategies in the context of limited vaccine supply in the Netherlands. MethodsOnline survey in a convenience sample of gay, bisexual and other men who have sex with men, including transgender persons (22/07-05/09/2022, the Netherlands). We assessed determinants for being (un)willing to accept vaccination. We used multivariable multinominal regression and logistic regression analyses, calculating adjusted odds ratios (aOR) and 95 percent confidence-intervals. An open question asked for campaigning and procedural recommendations. ResultsOf respondents, 81.5% (n = 1,512/1,856) were willing to accept vaccination; this was 85.2% (799/938) in vaccination-eligible people and 77.7% (713/918) in those non-eligible. Determinants for non-acceptance included: urbanization (rural: aOR:2.2;1.2-3.7; low-urban: aOR:2.4;1.4-3.9; vs. high-urban), not knowing mpox-vaccinated persons (aOR:2.4;1.6-3.4), and lack of connection to gay/queer-community (aOR:2.0;1.5-2.7). Beliefs associated with acceptance were: perception of higher risk/severity of mpox, higher protection motivation, positive outcome expectations post vaccination, and perceived positive social norms regarding vaccination. Respondents recommended better accessible communication, delivered regularly and stigma-free, with facts on mpox, vaccination and procedures, and other preventive options. Also, they recommended, "vaccine provision also at non-clinic settings, discrete/anonymous options, self-registration" to be vaccinated and other inclusive vaccine-offers (e.g., also accessible to people not in existing patient-registries). ConclusionIn the public health response to the mpox outbreak, key is a broad and equitable access to information, and to low-threshold vaccination options for those at highest risk. Communication should be uniform and transparent and tailored to beliefs, and include other preventive options. Mpox vaccine willingness was high. Public health efforts may be strengthened in less urbanized areas and reach out to those who lack relevant (community) social network influences
First Discovery of a Fast Radio Burst at 350 MHz by the GBNCC Survey
We report the first discovery of a fast radio burst (FRB), FRB 20200125A, by
the Green Bank Northern Celestial Cap (GBNCC) Pulsar Survey conducted with the
Green Bank Telescope at 350 MHz. FRB 20200125A was detected at a Galactic
latitude of 58.43 degrees with a dispersion measure of 179 pc cm, while
electron density models predict a maximum Galactic contribution of 25 pc
cm along this line of sight. Moreover, no apparent Galactic foreground
sources of ionized gas that could account for the excess DM are visible in
multi-wavelength surveys of this region. This argues that the source is
extragalactic. The maximum redshift for the host galaxy is ,
corresponding to a maximum comoving distance of approximately 750 Mpc. The
measured peak flux density for FRB 20200125A is 0.37 Jy, and we measure a pulse
width of 3.7 ms, consistent with the distribution of FRB widths observed at
higher frequencies. Based on this detection and assuming an Euclidean flux
density distribution of FRBs, we calculate an all-sky rate at 350 MHz of
FRBs sky day above a peak flux
density of 0.42 Jy for an unscattered pulse having an intrinsic width of 5 ms,
consistent with rates reported at higher frequencies. Given the recent
improvements in our single-pulse search pipeline, we also revisit the GBNCC
survey sensitivity to various burst properties. Finally, we find no evidence of
interstellar scattering in FRB 20200125A, adding to the growing evidence that
some FRBs have circumburst environments where free-free absorption and
scattering are not significant.Comment: 15 pages, 6 figures, Submitted to Ap
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