6,304 research outputs found
Making a difference - the appropriate use of web technology
Much has been written elsewhere about how, different Information Technology tools, can in principle be used by groups or communities to make their web sites more effective for Continued Professional Development. In practice, complex use is not often the case. In particular, three sites were studied in Scotland, which provided web facilities for the over 60s. The sites, and the communities they served, used only simple Information Technology. Nevertheless, they enabled their communities to participate effectively, on the 'right side', of the European population's 'digital divide'
Projected impacts of 21st century climate change on diapause in Calanus finmarchicus
Diapause plays a key role in the life cycle of high latitude zooplankton. During diapause animals avoid starving in winter by living in deep waters where metabolism is lower and met by lipid reserves. Global warming is therefore expected to shorten the maximum potential diapause duration by increasing metabolic rates and by reducing body size and lipid reserves. This will alter the phenology of zooplankton, impact higher trophic levels and disrupt biological carbon pumps. Here we project the impacts of climate change on the key North Atlantic copepod Calanus finmarchicus under IPCC RCP 8.5. Potential diapause duration is modelled in relation to body size and overwintering temperature. The projections show pronounced geographic variations. Potential diapause duration reduces by more than 30% in the Western Atlantic, whereas in the key overwintering centre of the Norwegian Sea it changes only marginally. Surface temperature rises, which reduce body size and lipid reserves, will have a similar impact to deep water changes on diapause in many regions. Because deep water warming lags that at the surface, animals in the Labrador Sea could offset warming impacts by diapausing in deeper waters. However, the ability to control diapause depth may be limited
The Nuclear Ionized Gas in the Radio Galaxy M84 (NGC 4374)
We present optical images of the nucleus of the nearby radio galaxy M84 (NGC
4374 = 3C272.1) obtained with the Wide Field/Planetary Camera 2 (WFPC2) aboard
the Hubble Space Telescope (HST). Our three images cover the H + [N II]
emission lines as well as the V and I continuum bands. Analysis of these images
confirms that the H + [N II] emission in the central 5'' (410 pc) is
elongated along position angle (P.A.) \approx 72\arcdeg, which is roughly
parallel to two nuclear dust lanes.Our high-resolution images reveal that the
H + [N II] emission has three components, namely a nuclear gas disk,an
`ionization cone', and outer filaments. The nuclear disk of ionized gas has
diameter pc and major axis P.A. \approx 58\arcdeg \pm
6\arcdeg. On an angular scale of 0\farcs5, the major axis of this nuclear
gas disk is consistent with that of the dust. However, the minor axis of the
gas disk (P.A. \approx 148\arcdeg) is tilted with respect to that of the
filamentary H + [N II] emission at distances > 2'' from the nucleus;
the minor axis of this larger scale gas is roughly aligned with the axis of the
kpc-scale radio jets (P.A. \approx 170\arcdeg). The ionization cone (whose
apex is offset by \approx 0\farcs3 south of the nucleus) extends 2'' from the
nucleus along the axis of the southern radio jet. This feature is similar to
the ionization cones seen in some Seyfert nuclei, which are also aligned with
the radio axes.Comment: 11 pages plus 4 figure
Constraining the Kahler Moduli in the Heterotic Standard Model
Phenomenological implications of the volume of the Calabi-Yau threefolds on
the hidden and observable M-theory boundaries, together with slope stability of
their corresponding vector bundles, constrain the set of Kaehler moduli which
give rise to realistic compactifications of the strongly coupled heterotic
string. When vector bundles are constructed using extensions, we provide simple
rules to determine lower and upper bounds to the region of the Kaehler moduli
space where such compactifications can exist. We show how small these regions
can be, working out in full detail the case of the recently proposed Heterotic
Standard Model. More explicitely, we exhibit Kaehler classes in these regions
for which the visible vector bundle is stable. On the other hand, there is no
polarization for which the hidden bundle is stable.Comment: 28 pages, harvmac. Exposition improved, references and one figure
added, minor correction
Tubuloglomerular feedback and interstitial pressure in obstructive nephropathy
Tubuloglomerular feedback and interstitial pressure in obstructive nephropathy. The possible role of the tubuloglomerular feedback (TGF) mechanism in the altered glomerular hemodynamics and tubular reabsorption which occur with prolonged (24-hr) ureteral obstruction and the changes in renal interstitial hydrostatic and oncotic pressure which may modulate TGF sensitivity were examined. The proximal tubule stop-flow pressure (PSF) response to increased distal tubular flow rates (TGF activity) was determined in rats with sham operation, 24-hr unilateral ureteral obstruction (UUO), or 24-hr bilateral ureteral obstruction (BUO), both before and for 2 hr after relief of obstruction. Subcapsular hydrostatic pressure, lymph flow and oncotic pressure, clearance and excretory data were measured in the second series of animals. During and after release of UUO, TGF sensitivity was increased, as indicated by the marked decrease in the loop perfusion rate at which 50% of the maximum decrease in PSF occurred (the turning point of TGF activation). Interstitial oncotic pressure but not hydrostatic pressure was significantly increased in UUO kidneys. In BUO rats, the turning point for TGF activation was slightly higher than the controls and the change in PSF with maximum loop perfusion rates was reduced, indicating a blunting of the TGF response before and particularly during postobstructive diuresis after release of BUO. Interstitial hydrostatic and oncotic pressures were both slightly increased resulting in no changes in net interstitial Starling forces. We conclude that enhanced TGF sensitivity after release of prolonged UUO, associated with increased interstitial oncotic pressure, may play a role in preventing postobstructive diuresis, while the blunting of TGF sensitivity after BUO may contribute to this phenomenon.Rétrocontrôle glomérulo-tubulaire et pression interstitielle au cours de la néphropathie obstructive. Le rôle possible du mécanisme de rétrocontrôle glomérulo-tubulaire (TGF) dans l'altération de l'hémadynamique glomérulaire et la réabsorption tubulaire qui se produisent lors d'une obstruction urétérale prolongée (24 heures) et les modifications des pressions hydrostatiques et oncotiques interstitielles rénales qui pourraient moduler la sensibilité TGF ont été étudiés. La réponse de pression en flux interrompu (PSF) du tubule proximal à une augmentation des débits tubulaires distaux a été déterminée chez des rats ayant subi un simulacre d'intervention, lors d'une obstruction urétérale unilatérale de 24 heures (UUO) ou lors d'une obstruction urétérale bilatérale de 24 heures (BUO), avant et 2 heures après la levée de l'obstruction. La pression hydrostatique sous-capsulaire, le flux et la pression oncotique lymphatiques, les paramètres de clearance et d'excrétion ont été mesurés chez une deuxième série d'animaux. Pendant et après levée de l'UUO, la sensibilité TGF a augmenté, comme le montrait la diminution marquée du débit de perfusion de l'anse pour lequel 50% de la chute maximale de PSF se produisait (le point d'inflexion de l'activation TGF). La pression oncotique mais non la pression hydrostatique interstitielle était significativement accrue dans les reins UUO. Chez les rats BUO, le point d'inflexion de l'activation TGF était légèrement plus élevé que chez les contrôles, et la modification de PSF aux débits de perfusion de l'anse maxima était diminuée, indiquant une altération de la réponse TGF avant et surtout pendant la diurèse post-obstructive, après levée de la BUO. Les pressions interstitielles hydrostatiques et oncotiques légèrement augmentées, d'où l'absence de modification des forces de Starling interstitielles nettes. Nous concluons que l'augmentation de la sensibilité TGF après levée d'une UUO prolongée associée à une élévation de la pression oncotique interstitielle, pourrait jouer un rôle pour prévenir la diurèse post-obstructive, alors que l'altération de la sensibilité TGF après BUO pourrait contribuer à ce phénomène
Recommended from our members
Inferred summer precipitation for southern Ontario back to AD 610, as reconstructed from ring widths of Thuja occidentalis
We present a network of seven ring-width chronologies of eastern white-cedar (Thuja occidentalis L.) from the Niagara Escarpment in southern Ontario, Canada. Using principal component regression, a 350-year June-July precipitation reconstruction (SOR) is developed for the region. Prior to the 20th century, the SOR series shows reasonable coherence, particularly at the decadal scale, with an independent tree-ring-based reconstruction of the Palmer drought severity index (PDSI) for roughly the same region. A weakening of the tree-growth – climate relationship in recent decades results in a regression model explaining 21% of the variance in the original climate series when the recent data are used for calibration. We therefore compromise with a model, calibrated for the period 1900–1960, which explains 33% of the variance. The model, while not terribly strong, does pass verification tests, indicating some degree of predictive skill. The longest chronology in our network, the 2787-year Flowerpot Island (FLOW) chronology, also exhibits common variability with the PDSI reconstruction, particularly on decadal and longer time scales and was used to infer hydroclimatic conditions back to AD 610. The combined information of the SOR, PDSI, and FLOW series suggests that dry conditions existed for the periods 1700–1725, 1750–1800, and 1840–1900, and wet conditions for the periods 1675–1700, 1730–1750, and 1810–1840. Over longer time scales, the FLOW chronology shows that summer precipitation was particularly variable during the 7th, 9th, 13th, and 16th centuries
Executive Summary: Diagnosis and Management of Prosthetic Joint Infection: Clinical Practice Guidelines by the Infectious Diseases Society of Americaa
These guidelines are intended for use by infectious disease specialists, orthopedists, and other healthcare professionals who care for patients with prosthetic joint infection (PJI). They include evidence-based and opinion-based recommendations for the diagnosis and management of patients with PJI treated with debridement and retention of the prosthesis, resection arthroplasty with or without subsequent staged reimplantation, 1-stage reimplantation, and amputatio
- …