4,066 research outputs found
Multi-thermal dynamics and energetics of a coronal mass ejection in the low solar atmosphere
The aim of this work is to determine the multi-thermal characteristics and
plasma energetics of an eruptive plasmoid and occulted flare observed by Solar
Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA). We study an event
from 03-Nov-2010 (peaking at 12:20UT in GOES soft X-rays) of a coronal mass
ejection and occulted flare which demonstrates the morphology of a classic
erupting flux rope. The high spatial, and time resolution, and six coronal
channels, of the SDO/AIA images allows the dynamics of the multi-thermal
emission during the initial phases of eruption to be studied in detail. The
Differential Emission Measure (DEM) is calculated, using an optimised version
of a regularized inversion method (Hannah & Kontar 2012), for each pixel across
the six channels at different times, resulting in emission measure maps and
movies in a variety of temperature ranges. We find that the core of the
erupting plasmoid is hot (8-11, 11-14MK) with a similarly hot filamentary
"stem" structure connecting it to the lower atmosphere, which could be
interpreted as the current sheet in the flux rope model, though is wider than
these models suggest. The velocity of the leading edge of the eruption is
597-664 km s in the temperature range 3-4MK and between 1029-1246
km s for 2-3MK. We estimate the density (in 11-14 MK) of the
erupting core and stem during the impulsive phase to be about
cm, cm, cm in the plasmoid
core, stem and surrounding envelope of material. This gives thermal energy
estimates of erg, erg and
erg. The kinetic energy for the core and envelope is slightly smaller. The
thermal energy of the core and current sheet grows during the eruption,
suggesting continuous influx of energy presumably via reconnection.Comment: Submitted to A&A: in revisio
Ethnicity and health: key themes in a developing field
Ethnicity is a social division that is increasingly difficult to ignore. Ethnicity has to be considered alongside other social divisions including socioeconomic status which is crucial to explaining minority disadvantages in health. Identity is a key dimension of ethnicity, which encompasses self-ascribed and externally-imposed elements. The stigma associated with particular conditions, combined with the effects of racism and economic marginalization, can be central to some minority groups' ability to discuss disease and seek treatment. In a world where human rights are taken seriously, minority ethnic groups' presence in research has to become a routine consideration, rather than an optional extra. In research, as in service provision, planning for linguistic and cultural diversity represents additional work and will require extra resources
Locating ethnicity and health: exploring concepts and contexts
With the rapid development of ethnicity and health as a field of sociological research, this paper seeks to re-evaluate the development of ideas around ethnicity, 'race' and culture and consider how they have been applied to the question of health. Ethnicity as a social characteristic is contingent on the situation in which it is manifest. The process of marking 'other' ethnic groups includes stereotyping and racialisation, a process through which 'racial' or ethnic differences predominate to the exclusion of a consideration of social, economic and power relations. In the British context, the history of empire and medicine's justification of racist treatment of enslaved and colonised people, is relevant to understanding how ethnic and cultural differences have come to be essentialised and pathologised. Immigration to Britain only became a mass phenomenon after World War II, with settlement patterns following employment opportunities and kinship alliances. The state has a longstanding history of 'managing' diversity, sometimes essentialising differences between groups, at other times tackling disadvantage and discrimination experiences through policy action. Sociologists of health were slow to study ethnicity, with initial research coming from tropical disease specialists. The tendency of medicine to pathologise minority cultures is explored through case studies of the approach to rickets and the assessment of health risks associated with consanguineous marriage. Anti-racist approaches have encouraged the consideration of discrimination against and socioeconomic position of minorities. The field has developed with work on nomenclature and the operationalisation of ethnic identity, necessary to study health inequalities between ethnic groups and paying due heed to the contribution of socioeconomic position and racism to group experiences. Research into chronic conditions with complex analysis of a number of distinct contributory variables has been published of late. However, the excessive focus on South Asians and the record of measuring, analysing, but not necessarily tackling health disadvantage, are problems that remain to be addressed
Planet Shadows in Protoplanetary Disks. I: Temperature Perturbations
Planets embedded in optically thick passive accretion disks are expected to
produce perturbations in the density and temperature structure of the disk. We
calculate the magnitudes of these perturbations for a range of planet masses
and distances. The model predicts the formation of a shadow at the position of
the planet paired with a brightening just beyond the shadow. We improve on
previous work on the subject by self-consistently calculating the temperature
and density structures under the assumption of hydrostatic equilibrium and
taking the full three-dimensional shape of the disk into account rather than
assuming a plane-parallel disk. While the excursion in temperatures is less
than in previous models, the spatial size of the perturbation is larger. We
demonstrate that a self-consistent calculation of the density and temperature
structure of the disk has a large effect on the disk model. In addition, the
temperature structure in the disk is highly sensitive to the angle of incidence
of stellar irradition at the surface, so accurately calculating the shape of
the disk surface is crucial for modeling the thermal structure of the disk.Comment: 14 pages, 14 figures. To appear in Ap
RAGE Signaling in Skeletal Biology
PURPOSE OF REVIEW:
The receptor for advanced glycation end products (RAGE) and several of its ligands have been implicated in the onset and progression of pathologies associated with aging, chronic inflammation, and cellular stress. In particular, the role of RAGE and its ligands in bone tissue during both physiological and pathological conditions has been investigated. However, the extent to which RAGE signaling regulates bone homeostasis and disease onset remains unclear. Further, RAGE effects in the different bone cells and whether these effects are cell-type specific is unknown. The objective of the current review is to describe the literature over RAGE signaling in skeletal biology as well as discuss the clinical potential of RAGE as a diagnostic and/or therapeutic target in bone disease.
RECENT FINDINGS:
The role of RAGE and its ligands during skeletal homeostasis, tissue repair, and disease onset/progression is beginning to be uncovered. For example, detrimental effects of the RAGE ligands, advanced glycation end products (AGEs), have been identified for osteoblast viability/activity, while others have observed that low level AGE exposure stimulates osteoblast autophagy, which subsequently promotes viability and function. Similar findings have been reported with HMGB1, another RAGE ligand, in which high levels of the ligand are associated with osteoblast/osteocyte apoptosis, whereas low level/short-term administration stimulates osteoblast differentiation/bone formation and promotes fracture healing. Additionally, elevated levels of several RAGE ligands (AGEs, HMGB1, S100 proteins) induce osteoblast/osteocyte apoptosis and stimulate cytokine production, which is associated with increased osteoclast differentiation/activity. Conversely, direct RAGE-ligand exposure in osteoclasts may have inhibitory effects. These observations support a conclusion that elevated bone resorption observed in conditions of high circulating ligands and RAGE expression are due to actions on osteoblasts/osteocytes rather than direct actions on osteoclasts, although additional work is required to substantiate the observations. Recent studies have demonstrated that RAGE and its ligands play an important physiological role in the regulation of skeletal development, homeostasis, and repair/regeneration. Conversely, elevated levels of RAGE and its ligands are clearly related with various diseases associated with increased bone loss and fragility. However, despite the recent advancements in the field, many questions regarding RAGE and its ligands in skeletal biology remain unanswered
PREVIEW; Maryland Casualty Company v. The Asbestos Claims Court, and the Honorable Amy Eddy, Asbestos Claims Court Judge: \u3cem\u3eWhat Duty does a Workers\u27 Compensation Insurer Owe the Employees of its Insured?\u3c/em\u3e
This case presents two significant issues. The overarching issue is whether a Writ of Supervisory Control will be granted to resolve the underlying issue: what duty, if any, a workers’ compensation insurer owes the employees of its insured. The resolution of the underlying issue will be an important one, both within the multitude of pending asbestos claims in Montana and beyond. The Petitioner, Maryland Casualty Company, claims the Asbestos Claims Court used an improper standard in determining that Maryland Casualty Company owed a duty to the employees of its insured, W.R. Grace & Company
The Stigmatization of Vaginal Masturbation and Its Effect on Sexual Pleasure
Starting in ancient times and continuing for the next several centuries vaginal and penile masturbation were viewed as unnatural in the religious sense as well as unhealthy. Physicians such as Galen and Hippocrates decided that masturbation caused physical damage including spinal cord deterioration. Until the mid-20th-century there was heavy punishment for those who masturbated, these punishments ranged from clitoridectomy and circumcision to straight jackets. It was not until 1948 when Alfred Kinsey published a study titled, “Sexual Behavior In The Human Male, that feelings towards masturbating started to shift. The study found that masturbation does not cause ill health. Although this case created a large amount of backlash, it paved the way for the slow progression towards the acceptance of masturbation for males. While masturbation is more accepted today, studies still show that it is more talked about among men than women and that more men masturbate than women. Studies also show an increase in sexual pleasure during intercourse for women amongst those who masturbate. Orgasming during sex for women is not always easy but usually becomes easier through masturbation. Men have a far easier time orgasming during sex and separately, masturbation is less stigmatized for them. Therefore, I have theorized that as the stigmatization of vaginal masturbation increases, orgasms during sex decrease. In my thesis exhibition, I created a comfortable and private space where viewers could learn about vaginal masturbation. Through making two installations that provided space for multiple viewers, I also stimulated conversation
Constraints on the Formation of the Planet Around HD188753A
The claimed discovery of a Jupiter-mass planet in the close triple star
system HD 188753 poses a problem for planet formation theory. A circumstellar
disk around the planet's parent star would be truncated close to the star,
leaving little material available for planet formation. In this paper, we
attempt to model a protoplanetary disk around HD 188753A using a fairly simple
alpha-disk model, exploring a range of parameters constrained by observations
of T Tauri-type stars. The disk is truncated to within 1.5 to 2.7 AU, depending
on model parameters. We find that the in situ formation of the planet around HD
188753A is implausible.Comment: Accepted version, to appear in ApJ. 23 pages, 5 figures (3 in color
Quantitative profiling of the human substantia nigra proteome from laser-capture microdissected FFPE tissue
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