1,966 research outputs found
SN 2015U: A Rapidly Evolving and Luminous Type Ibn Supernova
Supernova (SN) 2015U (also known as PSN J07285387+3349106) was discovered in
NGC 2388 on 2015 Feb. 11. A rapidly evolving and luminous event, it showed
effectively hydrogen-free spectra dominated by relatively narrow helium P-Cygni
spectral features and it was classified as a SN Ibn. In this paper we present
photometric, spectroscopic, and spectropolarimetric observations of SN 2015U,
including a Keck/DEIMOS spectrum (resolution 5000) which fully
resolves the optical emission and absorption features. We find that SN 2015U is
best understood via models of shock breakout from extended and dense
circumstellar material (CSM), likely created by a history of mass loss from the
progenitor with an extreme outburst within 1-2 yr of core collapse (but
we do not detect any outburst in our archival imaging of NGC 2388). We argue
that the high luminosity of SN 2015U was powered not through Ni decay
but via the deposition of kinetic energy into the ejecta/CSM shock interface.
Though our analysis is hampered by strong host-galaxy dust obscuration (which
likely exhibits multiple components), our dataset makes SN 2015U one of the
best-studied Type Ibn supernovae and provides a bridge of understanding to
other rapidly fading transients, both luminous and relatively faint.Comment: 20 pages, 15 figures, 4 table
Early postpartum restingâstate functional connectivity for mothers receiving buprenorphine treatment for opioid use disorder: A pilot study
Between 1999 and 2014, the prevalence of opioid use disorder (OUD) among pregnant women quadrupled in the USA. The standard treatment for peripartum women with OUD is buprenorphine. However, the maternal behavior neurocircuit that regulates maternal behavior and motherâinfant bonding has not been previously studied for human mothers receiving buprenorphine treatment for OUD (BT). Rodent research shows opioid effects on reciprocal inhibition between maternal care and defence maternal brain subsystems: the hypothalamus and periaqueductal gray, respectively. We conducted a longitudinal functional magnetic resonance imaging (fMRI) pilot study in humans to specifically examine restingâstate functional connectivity (rsâFC) between the periaqueductal gray and hypothalamus, as well as to explore associations with maternal bonding for BT. We studied 32 mothers who completed fMRI scans at 1Â month (T1) and 4Â months postpartum (T2), including seven mothers receiving buprenorphine for OUD and 25 nonâOUD mothers as a comparison group (CG). The participants underwent a 6âminute restingâstate fMRI scan at each time point. We measured potential bonding impairments using the Postpartum Bonding Questionnaire to explore how rsâFC with periaqueductal gray is associated with bonding impairments. Compared to CG, BT mothers differed in periaqueductal grayâdependent rsâFC with the hypothalamus, amygdala, insular cortex and other brain regions at T1, with many of these differences disappearing at T2, suggesting potential therapeutic effects of continuing buprenorphine treatment. In contrast, the ârejection and pathological angerâ subscale of the Postpartum Bonding Questionnaire at T1 and T2 was associated with the T1âtoâT2 increases in periaqueductal grayâdependent rsâFC with the hypothalamus and amygdala. Preliminary evidence links maternal bonding problems for mothers with OUD early in the postpartum to connectivity between specific care and defence maternal brain circuits, which may be mitigated by buprenorphine treatment. This exploratory study supports a potential mechanism for investigating both the therapeutic benefits and risks of opioids for maternal care and bonding with infants.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151866/1/jne12770.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151866/2/jne12770_am.pd
Classical integrability of Schrodinger sigma models and q-deformed Poincare symmetry
We discuss classical integrable structure of two-dimensional sigma models
which have three-dimensional Schrodinger spacetimes as target spaces. The
Schrodinger spacetimes are regarded as null-like deformations of AdS_3. The
original AdS_3 isometry SL(2,R)_L x SL(2,R)_R is broken to SL(2,R)_L x U(1)_R
due to the deformation. According to this symmetry, there are two descriptions
to describe the classical dynamics of the system, 1) the SL(2,R)_L description
and 2) the enhanced U(1)_R description. In the former 1), we show that the
Yangian symmetry is realized by improving the SL(2,R)_L Noether current. Then a
Lax pair is constructed with the improved current and the classical
integrability is shown by deriving the r/s-matrix algebra. In the latter 2), we
find a non-local current by using a scaling limit of warped AdS_3 and that it
enhances U(1)_R to a q-deformed Poincare algebra. Then another Lax pair is
presented and the corresponding r/s-matrices are also computed. The two
descriptions are equivalent via a non-local map.Comment: 20 pages, no figure, further clarification and references adde
A systematic review of school-based sexual health interventions to prevent STI/HIV in sub-Saharan Africa
Background
The HIV/AIDS epidemic remains of global significance and there is a need to target (a) the adolescent age-groups in which most new infections occur; and (b) sub-Saharan Africa where the greatest burden of the epidemic lies. A focused systematic review of school-based sexual health interventions in sub-Saharan Africa to prevent HIV/AIDS and Sexually Transmitted Infections (STI) in this age group was therefore conducted.
Methods
Searches were conducted in Medline, Embase, Cinahl and PsychINFO according to agreed a priori criteria for studies published between 1986 and 2006. Further searches were conducted in UNAIDS and WHO (World Health Organization) websites, and 'Google'. Relevant journals were hand-searched and references cited in identified articles were followed up.
Data extraction and quality assessment was carried out on studies selected for full text appraisal, and results were analysed and presented in narrative format.
Results
Some 1,020 possible titles and abstracts were found, 23 full text articles were critically appraised, and 12 articles (10 studies) reviewed, reflecting the paucity of published studies conducted relative to the magnitude of the HIV epidemic in sub-Saharan Africa. Knowledge and attitude-related outcomes were the most associated with statistically significant change. Behavioural intentions were more difficult to change and actual behaviour change was least likely to occur. Behaviour change in favour of abstinence and condom use appeared to be greatly influenced by pre-intervention sexual history.
Conclusion
There is a great need in sub-Saharan Africa for well-evaluated and effective school-based sexual health interventions
Fusarium graminearum in a Papilloma Virus Infected Friesian Bull in Vom, Nigeria: Case Report
Importation of exotic cattle to improve the yield and productivityof the local 'White Fulani' breed of cattle has been on the rise inNigeria. The problem most farmers faces with the Friesian hasalways been the adaptation to the weather and endemic diseaseconditions in Nigeria. Fungal infections represent an importantcomplication for immunosuppressed animals and are associatedwith high morbidity and mortality (De Pauw and Meunier, 1999).Fusarium is one of the most important fungal genera, whichincludes many species that are pathogenic to plants and responsible for a broad range of diseases while others are highly mycotoxigenic (Viquez et al., ) and some cause opportunistic infections in humans and in farm animals. Fusarium graminearum (Gibberella zeae) is an importantpathogen of commercial crops such as wheat, maize, and rice.Infection with F. graminearum causes yield losses in grains anddegrades their nutritive, physical and chemical qualities, resultingin their being used for animal feed rather than for human consumption (Charmley et al., 1994). A contaminated crop can be salvaged by feeding it to livestock or poultry, but further losses may be incurred due to the negative effects of mycotoxins on animal performance. Potent toxins such as the estrogenic toxin zearalenone (F-2) have been reported by Vesonder and Hesseltine, (1980) but the most common mycotoxins produced byF. graminearum are deoxynivalenol (DON, also known as vomitoxin), 15-acetyldeoxynivalenol, and nivalenol belonging to a group of compounds known as trichothecenes (Homdork et al., 2000; Council for Agricultural Science and Technology, CAST, 2003). These mycotoxins are known to diminish feed consumption in domestic livestock, especially swine (CAST 2003). Because of their apparent tolerance for higher levels of dietary DON, Fusarium-infested grains are often fed to cattle or sheep asopportunity feeds. This may be due to little or insufficient information describing the pathogenesis and the ability of this plant pathogen to survive as they move through the gastrointestinal tract of cattle or on a compromised skin (Kedar and Gemerlyn, 2008)
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