679 research outputs found
Report drawn up on behalf of the Committee on Development and Cooperation on the situation in the Central African Republic. Working Documents 1980-1981, Document 1-149/80, 8 May 1980
Resource tiered reviews – a provisional reporting checklist
AFJEM is committed to publishing review articles that will benefit acute care providers, independent of the resources available to them. As a result we have compiled a checklist aimed specifically at best evidence in the resource-restricted setting (Table 1). The aim is to guide authors in producing a report which is a combination between a clinical guideline and a systematic review. Best available evidence, using a transparent and systematic approach to find and evaluate relevant studies, is still key; but with additional focus on resource availability. In effect it will be more rigorous than a narrative review but less time-consuming than a systematic review or meta-analysis. In order to apply the content to different resource levels, authors are advised to start by describing the very best evidence available; then assume the resources for this level are not available and describe the next tier of evidence until all options are exhausted. For example, if we return to our patient with chest pain: the recommended treatment for a patient with STEMI is primary percutaneous coronary intervention; if this treatment is not available, then thrombolytics should be considered; if that is not available then antiplatelet therapy and anticoagulation should be used, and so on and so forth
Outflows from young objects observed with the ISO-LWS I. Fine structure lines [O I] 63, [O I]145 and [C II]157 micron
Far infrared fine structure line data from the ISO archive have been
extracted for several hundred YSOs and their outflows, including molecular (CO)
outflows, optical jets and Herbig-Haro (HH) objects. Given the importance of
these lines to astrophysics, their excitation and transfer ought to be
investigated in detail and, at this stage, the reliability of the diagnostic
power of the fine structure transitions of O I and C II has been examined.
Several issues, such as the extremely small intensity ratios of the oxygen 63
micron to 145 micron lines, are still awaiting an explanation. It is
demonstrated that, in interstellar cloud conditions, the 145 micron line is
prone to masing, but that this effect is likely an insufficient cause of the
line ratio anomaly observed from cold dark clouds. Very optically thick
emission could in principle also account for this, but would need similar,
prohibitively high column densities and must therefore be abondoned as a viable
explanation. One is left with [O I] 63 micron self absorption by cold and
tenuous foreground gas, as has been advocated for distant luminous sources.
Recent observations with the submillimeter observatory Odin support this
scenario also in the case of nearby dark molecular clouds. On the basis of this
large statistical material we are led to conclude that in star forming regions,
the [O I] and [C II] lines generally have only limited diagnostic value.Comment: 8 pages, 8 figures (in color), to appear in Astronomy & Astrophysic
The deep-sea hub of the ANTARES neutrino telescope
The ANTARES neutrino telescope, currently under construction at 2500 m depth off the French Mediterranean coast, will contain 12 detection lines, powered and read out through a deep-sea junction box (JB) hub. Electrical energy from the shore station is distributed through a transformer with multiple secondary windings and a plugboard with 16 deep sea-mateable electro-optic connectors. Connections are made to the JB outputs using manned or remotely operated submersible vehicles. The triply redundant power management and slow control system is based on two identical AC-powered systems, communicating with the shore through 160 Mb/s fibre G-links and a third battery-powered system using a slower link. We describe the power and slow control systems of the underwater hub
Reactive oxygen-related diseases: therapeutic targets and emerging clinical indications
SIGNIFICANCE
Enhanced levels of reactive oxygen species (ROS) have been associated with different disease states. Most attempts to validate and exploit these associations by chronic antioxidant therapies have provided disappointing results. Hence, the clinical relevance of ROS is still largely unclear.
RECENT ADVANCES
We are now beginning to understand the reasons for these failures, which reside in the many important physiological roles of ROS in cell signaling. To exploit ROS therapeutically, it would be essential to define and treat the disease-relevant ROS at the right moment and leave physiological ROS formation intact. This breakthrough seems now within reach.
CRITICAL ISSUES
Rather than antioxidants, a new generation of protein targets for classical pharmacological agents includes ROS-forming or toxifying enzymes or proteins that are oxidatively damaged and can be functionally repaired.
FUTURE DIRECTIONS
Linking these target proteins in future to specific disease states and providing in each case proof of principle will be essential for translating the oxidative stress concept into the clinic. Antioxid. Redox Signal. 23, 1171-1185
On the gas temperature in circumstellar disks around A stars
In circumstellar disks or shells it is often assumed that gas and dust
temperatures are equal where the latter is determined by radiative equilibrium.
This paper deals with the question whether this assumption is applicable for
tenous circumstellar disks around young A stars. In this paper the thin
hydrostatic equilibrium models described by Kamp & Bertoldi (2000) are combined
with a detailed heating/cooling balance for the gas. The most important heating
and cooling processes are heating through infrared pumping, heating due to the
drift velocity of dust grains, and fine structure and molecular line cooling.
Throughout the whole disk gas and dust are not efficiently coupled by
collisions and hence their temperatures are quite different. Most of the gas in
the disk models considered here stays well below 300 K. In the temperature
range below 300 K the gas chemistry is not much affected by T_gas and therefore
the simplifying approximation T_gas = T_dust can be used for calculating the
chemical structure of the disk. Nevertheless the gas temperature is important
for the quantitative interpretation of observations, like fine structure and
molecular lines.Comment: 16 pages, 31 figures, A&A accepted May 4, 200
The gas temperature in flaring disks around pre-main sequence stars
A model is presented which calculates the gas temperature and chemistry in
the surface layers of flaring circumstellar disks using a code developed for
photon-dominated regions. Special attention is given to the influence of dust
settling. It is found that the gas temperature exceeds the dust temperature by
up to several hundreds of Kelvins in the part of the disk that is optically
thin to ultraviolet radiation, indicating that the common assumption that
Tgas=Tdust is not valid throughout the disk. In the optically thick part, gas
and dust are strongly coupled and the gas temperature equals the dust
temperature. Dust settling has little effect on the chemistry in the disk, but
increases the amount of hot gas deeper in the disk. The effects of the higher
gas temperature on several emission lines arising in the surface layer are
examined. The higher gas temperatures increase the intensities of molecular and
fine-structure lines by up to an order of magnitude, and can also have an
important effect on the line shapes.Comment: 14 pages, 10 figures, accepted for publication in A&
Tracking of fluorescently labeled polymer particles reveals surface effects during shear-controlled aggregation
Surface chemistry is believed to be the key parameter affecting the aggregation and breakage of colloidal suspensions when subjected to shear. To date, only a few works dealt with the understanding of the role of the physical and chemical properties of the particles’ surface upon aggregation under shear. Previous studies suggested that surface modifications strongly affect polymer particles’ adhesion, but it was very challenging to demonstrate this effect and monitor these alterations upon prolonged exposure to shear forces. More importantly, the mechanisms leading to these changes remain elusive. In this work, shear-induced aggregation experiments of polymer colloidal particles have been devised with the specific objective of highlighting material transfer and clarifying the role of the softness of the particle’s surface. To achieve this goal, polymer particles with a core–shell structure comprising fluorescent groups have been prepared so that the surface’s softness could be tuned by the addition of monomer acting as a plasticizer and the percentage of fluorescent particles could be recorded over time via confocal microscopy to detect eventual material transfer among different particles. For the first time, material exchange occurring on the soft surface of core–shell polymer microparticles upon aggregation under shear was observed and proved. More aptly, starting from a 50% labeled/nonlabeled mixture, an increase in the percentage of particles showing a fluorescent signature was recorded over time, reaching a fraction of 70% after 5 h
Influence of the gender on the relationship between heart rate and blood pressure
Blood Pressure (BP) and Heart Rate (HR) provide information on clin-ical
condition along 24h. Both signals present circadian changes due to
sympa-thetic/parasympathetic control system that influence the relationship
between them. Moreover, also the gender could modify this relation, acting on
both con-trol systems. Some studies, using office measurements examined the
BP/HR re-lation, highlighting a direct association between the two variables,
linked to sus-pected coronary heart disease. Nevertheless, till now such
relation has not been studied yet using ambulatory technique that is known to
lead to additional prog-nostic information about cardiovascular risks. In order
to examine in a more ac-curate way this relation, in this work we evaluate the
influence of gender on the BP/HR relationship by using hour-to-hour 24h
ambulatory measurements. Data coming from 122 female and 50 male normotensive
subjects were recorded using a Holter Blood Pressure Monitor and the parameters
of the linear regression fit-ting BP/HR were calculated. Results confirmed
those obtained in previous stud-ies using punctual office measures in males and
underlined a significant relation between Diastolic BP and HR during each hour
of the day in females; a different trend in the BP/HR relation between genders
was found only during night-time. Moreover, the circadian rhythm of BP/HR is
similar in both genders but with different values of HR and BP at different
times of the day
Continuum and line modeling of disks around young stars II. Line diagnostics for GASPS from the DENT grid
Aims. We want to understand the chemistry and physics of disks on the basis
of a large unbiased and statistically relevant grid of disk models. One of the
main goals is to explore the diagnostic power of various gas emission lines and
line ratios for deriving main disk parameters such as the gas mass. Methods. We
explore the results of the DENT grid (Disk Evolution with Neat Theory) that
consists of 300 000 disk models with 11 free parameters. Through a statistical
analysis, we search for correlations and trends in an effort to find tools for
disk diagnostic. Results. All calculated quantities like species masses,
temperatures, continuum and line fluxes differ by several orders of magnitude
across the entire parameter space. The broad distribution of these quantities
as a function of input parameters shows the limitation of using a prototype T
Tauri or Herbig Ae/Be disk model. The statistical analysis of the DENT grid
shows that CO gas is rarely the dominant carbon reservoir in disks. Models with
large inner radii (10 times the dust condensation radius) and/or shallow
surface density gradients lack massive gas phase water reservoirs. Also, 60% of
the disks have gas temperatures averaged over the oxygen mass in the range
between 15 and 70 K; the average gas temperatures for CO and O differ by less
than a factor two. Studying the observational diagnostics, the [CII] 158 \mum
fine structure line flux is very sensitive to the stellar UV flux and presence
of a UV excess and it traces the outer disk radius (Rout). In the submm, the CO
low J rotational lines also trace Rout. Low [OI] 63/145 line ratios (< a few)
can be explained with cool atomic O gas in the uppermost surface layers leading
to self-absorption in the 63 \mum line; this occurs mostly for massive
non-flaring, settled disk models without UV excess. ... abbreviatedComment: 15 pages, 25 figures, accepted for publication in A&
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