Search

Ageing is associated with reductions in appetite and food intake leading to unintentional weight loss. Such weight loss, particularly through muscle mass reduction, is associated with muscle weakness and functional decline, which represent predictors of poor health outcomes and contribute to frailty in older adults. Exercise-induced anorexia is an established phenomenon in young adults; however appetite and energy intake (EI) responses to resistance exercise are unknown in older adults. Twenty healthy older adults (68 ± 5 years, BMI 26.2 ± 4.5 kg.m-2 ) undertook two 5-hour experimental trials. Participants rested for 30 minutes before being provided with a standardised breakfast (196 kcal, 75.2% carbohydrate, 8.9% protein and 15.9% fat). Participants then rested for 1-hour before completing: 1-hour resistance exercise bout followed by 2-hour of rest (RE) or, a control condition (CON) where participants rested for 3 hours, in a randomised crossover design. Appetite perceptions were measured throughout both trials and on cessation, an ad libitum meal was provided to assess EI. A repeated-measures ANOVA revealed no significant condition x time interaction for subjective appetite (p = 0.153). However, area under the curve for appetite was significantly lower in the RE compared with CON (49 ± 8mm•hour-1 vs. 52 ± 9mm•hour-1, p = 0.007, d = 0.27). There was no difference in EI (RE = 681 ± 246 kcal; CON = 673 ± 235 kcal; p = 0.865), suggesting that resistance exercise does not affect EI 2 hours post-exercise in older adults despite a significant but modest reduction in appetite over a 5-h period. In conclusion, resistance exercise may be an appropriate means for optimising muscle mass adaptations without attenuating acute EI of older adults.

This paper explores the combination of Attention Restoration Theory and immersive virtual technology as a novel therapy for short-term stress reduction in the workplace. The goal of this work is to understand how various immersive technologies impact the effect of both nature and urban environments on acute stress. In order to assess this, study participants were guided through “micro-vacations,” or a series of virtual nature or urban images, after being induced with stress. The micro-vacations were presented via three different virtual immersive technologies: a virtual reality (VR) experience using a headset in a booth, a GeoDome experience, or a 2D experience which acted as a control. Biometric, subjective mood and comfort data were gathered from the participants throughout the study in order to measure the changes in stress and mood before, during, and after the microvacation experiences. We hypothesize that the nature environments are more relaxing than the urban environments, and that both the VR booth and GeoDome will reduce stress levels in participants to a greater degree than the 2D images.

Stress and trauma are ubiquitous parameters of law enforcement and it is highly likely that police officers may experience symptoms of burnout and compassion fatigue. In the present chapter, the authors explore the definition and negative impact of compassion fatigue and burnout on police officers' health, wellbeing, and job performance. The overlap in symptomatology and the distinguishing factors between compassion fatigue and posttraumatic stress disorder (PTSD) are also considered. The authors address the stigma associated with an officer's reporting of mental health issues and discuss the maladaptive coping strategies that officers often employ instead of dealing with the experienced issue with adaptive way of coping. While maladaptive coping may suppress issues, those issues remain unresolved and can accumulate over time as officers are continuously exposed to traumatic, critical incidents throughout their careers. Additionally, compassion satisfaction has been reported to decrease amongst officers experiencing high levels of compassion fatigue, whereas burnout has been associated with a decreased sense of personal satisfaction for contributions made in the workplace. The impact of compassion fatigue and burnout are reversible and preventable as long as officers engage in healthy, holistic, and adaptive coping strategies to deal with stressors and traumatic incidents experienced on the job.

Several rare diseases are regularly identified during the prenatal and perinatal periods, including dysmelia. How these are communicated to parents has a marked emotional impact, but minimal research has investigated this. The purpose of this study was to explore parent experiences and preferences when their baby was diagnosed with dysmelia. Mothers and fathers were interviewed. Data were analyzed using thematic analysis. The overriding emotion parents experienced was shock, but the extent of this was influenced by several factors including their previous experience of disability. Four key needs of parents were identified, including the need for signposting to peer support organizations, for information, for sensitive communication, and for a plan regarding their child's care. Parents wanted immediate information provision and signposting to peer support, and for discussions regarding possible causes of the dysmelia or termination (in the case of prenatal identification) to be delayed until they had processed the news.

Periodontal-endodontic (perio-endo) lesions involve pulpal and periodontal disease in the same tooth and are seen routinely by dental practitioners. An unusual presentation of a perio-endo lesion in the lower left mandible is demonstrated. It caused significant buccal expansion and perforation of the lingual plate, and was provisionally diagnosed as a malignancy. CPD/Clinical Relevance: This case has highlighted the need for clinicians to be aware of the unusual way that periodontal-endodontic lesions may present both clinically and radiographically.

Invasive species management typically aims to promote diversity and wildlife habitat, but little is known about how management techniques affect wetland carbon (C) dynamics. Since wetland C uptake is largely influenced by water levels and highly productive plants, the interplay of hydrologic extremes and invasive species is fundamental to understanding and managing these ecosystems. During a period of rapid water level rise in the Laurentian Great Lakes, we tested how mechanical treatment of invasive plant Typha × glauca shifts plant-mediated wetland C metrics. From 2015 to 2017, we implemented large-scale treatment plots (0.36-ha) of harvest (i.e., cut above water surface, removed biomass twice a season), crush (i.e., ran over biomass once mid-season with a tracked vehicle), and Typha-dominated controls. Treated Typha regrew with approximately half as much biomass as unmanipulated controls each year, and Typha production in control stands increased from 500 to 1500 g-dry mass m-2 yr-1 with rising water levels (~10 to 75 cm) across five years. Harvested stands had total in-situ methane (CH4) flux rates twice as high as in controls, and this increase was likely via transport through cut stems because crushing did not change total CH4 flux. In 2018, one year after final treatment implementation, crushed stands had greater surface water diffusive CH4 flux rates than controls (measured using dissolved gas in water), likely due to anaerobic decomposition of flattened biomass. Legacy effects of treatments were evident in 2019; floating Typha mats were present only in harvested and crushed stands, with higher frequency in deeper water and a positive correlation with surface water diffusive CH4 flux. Our study demonstrates that two mechanical treatments have differential effects on Typha structure and consequent wetland CH4 emissions, suggesting that C-based responses and multi-year monitoring in variable water conditions are necessary to accurately assess how management impacts ecological function.

Overactive bladder (OAB) affects adults of all ages. The risk for medication-related adverse events (AEs) may differ between age groups, given age-related changes in pharmacokinetics and pharmacodynamics. No previous study has differentiated the risk of AEs between older and non-older adults with OAB. Our objective was to assess the risk of AEs and treatment discontinuations between older and non-older adults with OAB initiated on an antimuscarinic. We searched MEDLINE (PubMed interface), Embase, SCOPUS, and Cochrane Central Register for Controlled Trials in a previous analysis in February 2015 and repeated the search in August 2018, with no additional studies identified. Studies that delineated AEs or treatment discontinuations between the older and non-older (age

We present a 16-year-old boy with a history of ankylosis of the temporomandibular joint (TMJ) who had been treated with a costochondral graft and mandibular distraction. The distraction seems to have caused pulp canal obliteration of the lower right second premolar and lower right first molar on radiographic examination. To our knowledge this is the only reported instance of such damage related to mandibular distraction. We aim to highlight the risks of this complication and the importance of discussing it with patients as part of the process of informed consent.

Background and Hypothesis: There is an unmet need for interventions that prevent bone loss induced by sex steroid deficiency. Loss of estrogens or androgens increases ROS in bone. We hypothesized that diets containing blueberries with antioxidant properties would protect from bone loss induced by sex steroid deficiency, depending on sex and on the expression of Nrf2, a transcription factor that regulates the endogenous antioxidant response. Experimental Design: SHAM, ovariectomized (OVX), or orchidectomized (ORX) 4-month-old, wild type (WT) or Nrf2 knockout (KO) male and female mice were fed with control diet or diets containing 3 types of blueberries. Bone mineral density (BMD) and bone microarchitecture were measured by dual-energy x-ray absorptiometry and microscopic computed tomography, respectively; and gene expression was quantified in bone RNA by quantitative PCR. Results: Control-fed OVX or ORX mice exhibited the expected BMD loss, to a similar extent, in WT and KO mice. One of the blueberry diets (Montgomery) prevented bone loss, totally in females and partially in males; and prevented ~50% of microarchitecture deterioration in ORX mice, independently of Nrf2 expression. OVX and ORX decreased expression of estrogen-response-element gene C3 or androgen-response-element gene Rhox5, respectively, in both WT and KO mice fed control or Montgomery diets, indicating that bone protection is not due to estrogenic/androgenic actions of the diet. Conclusion and Potential Impact: Montgomery diet prevented bone loss due to sex steroid deficiency fully in females and partially in males. Thus, optimal skeletal benefits might be achieved by tailoring antioxidant-rich diets to patients of either sex.

The proliferation of social media usage has changed the way individuals express public discourse regarding social issues. These expressions and interactions form a digitally networked connective action, where actors share information and ideas about a specific social issue absent of hierarchical leadership. Previous studies have proposed these connective actions are influenced by associated offline events but have neglected to examine the actors in the network and how the composition of the networks change. Through the lens of connective action logic, this research seeks to explore the effects of offline events on connective action participation and interactions between communities. Using content and social network analyses, this research examined #BoycottNFL, a connective action created to discontinue support of the National Football League. Findings suggest associated offline trigger events affect the diversity of actors participating in connective action and fostering interactions between actors and communities of diverse backgrounds. Implications are discussed in the context of organizational strategies for addressing social issues and harnessing the power of social media to transform connective actions.

The Fostering Learning Improvements in Physics project is examining the international status of subject-based educational research in physics and the potential for work in this field to impact the teaching and learning of undergraduate physics in UK universities. While focused specifically on physics, outcomes of the project may be relevant to subject-based educational research and to teaching and learning within the physical sciences more generally. We report on the aims, approaches and current status at the mid-point of this one-year study.

BackgroundPatients can play a role in achieving an earlier diagnosis of cancer by monitoring and re-appraising symptoms after initially presenting to primary care. It is not clear what interventions exist, or what the components of an intervention to engage patients at this diagnostic stage are.AimThe review had two aims: 1) to identify interventions that involve patients, and 2) to establish key components for engaging patients in the diagnosis of cancer in primary care at the post-presentation stage.Design and settingEmpirical studies and non-empirical articles were identified searching Ovid MEDLINE, PsycINFO, and Embase databases, relevant journals, and available key author publication lists.MethodAbstracts and titles were screened against inclusion and exclusion criteria. Qualitative synthesis of empirical research and current opinion from across all articles was used to select, organise, and interpret findings.ResultsNo interventions were found. Sixteen articles provided suggestions for potential interventions and components important at the post-presentation stage. Factors contributing to patients not always being engaged in assisting with diagnosis, strategies to foster patient involvement, and moderators and benefits to patients and health services (proximal and distal outcomes) were captured in a logic model.ConclusionThere is an absence of interventions involving patients during the post-presentation stage of the diagnostic process. Limited literature was drawn upon to identify potential barriers and facilitators for engaging patients at this diagnostic stage, and to establish possible mechanisms of change and measurable outcomes. Findings can direct future research and the development of interventions.

Social responsibility has rapidly gained popularity among consumers specifically among Millennials born 1980 to 2000. Millennials are characterized by their willingness to get involved with social and political initiatives and a high affinity for technology. Literature has examined psychological antecedents and demographic characteristics of socially responsible (SR) consumers. To date, no research has explored the commitment to an identity as an underlying factor in understanding Millennials decision to engage in routes of SR consumption behavior. The purpose of this study is to explore the socio-cognitive process Millennials engage in when making SR consumption decisions. Using Identity theory and Symbolic Self-Completion theory as a conceptual framework, this research aims to contribute to the body of literature pertaining to Millennials and social responsibility. Structural equation modeling revealed a positive relationship between SR identity commitment and SR private and public consumption behavior, which was completely mediated by SR personal identity salience.

Aims: The aim of this study was to investigate the relationships between depressive symptoms, burnout and perceptions of patient safety. A mediation model was proposed whereby the association between symptoms of depression and patient safety perceptions was mediated by burnout. BACKGROUND: There is growing interest in the relationships between depressive symptoms and burnout in healthcare staff and the safety of patient care. Depressive symptoms are higher in healthcare staff than the general population and overlap conceptually with burnout. However, minimal research has investigated these variables in nurses. Given the conceptual overlap between depressive symptoms and burnout, there is also a need for an explanatory model outlining the relative contributions of these factors to patient safety. AIMS: To investigate the relationships between depressive symptoms, burnout and perceptions of patient safety. A mediation model was proposed whereby the association between symptoms of depression and patient safety perceptions was mediated by burnout. DESIGN: A cross-sectional questionnaire was distributed at three acute NHS Trusts. METHOD: Three-hundred and twenty-three hospital nursing staff completed measures of depressive symptoms, burnout and patient safety perceptions (including measures at the level of the individual and the work area/unit) between December 2015 - February 2016. RESULTS: When tested in separate analyses, depressive symptoms and burnout facets were each associated with both patient safety measures. Furthermore, the proposed mediation model was supported, with associations between depressive symptoms and patient safety perceptions fully mediated by burnout. CONCLUSION: These results suggest that symptoms of depression and burnout in hospital nurses may have implications for patient safety. However, interventions to improve patient safety may be best targeted at improving burnout in particular, with burnout interventions known to be most effective when focused at both the individual and the organisational level.

The Fostering Learning Improvements in Physics project is examining the international status of subject-based educational research in physics and the potential for work in this field to impact the teaching and learning of undergraduate physics in UK universities. While focused specifically on physics, outcomes of the project may be relevant to subject-based educational research and to teaching and learning within the physical sciences more generally. We report on the aims, approaches and current status at the mid-point of this one-year study.

Gender serves as an important basis for market segmentation and is frequently used because market segments are large enough to be profitable and are easily identified (Darley and Smith, 1995). Product aesthetics has been growing in importance for all industries and product categories, as it increases customer satisfaction and loyalty (Schmitt and Simonson, 1997). The purpose of this research is to explore how gender interacts with design complexity of hedonic and utilitarian products to influence consumers’ aesthetic preferences.

When I started this piece, I didn't remember. I had post-traumatic stress disorder. I thought I was writing a piece about making rugs. (1) [ILLUSTRATION OMITTED] I always had a fascination with bell sounds, and it was only after I had amassed quite a large collection that I began to think about why. (2) [ILLUSTRATION OMITTED] I was thinking about rugs, something me and Morty [Feldman] always shared. But when I started composing, I started thinking about my father, who loved the violin, and was always singing. And how the sound of the viola is like my father's voice. [ILLUSTRATION OMITTED] There's a feeliness to these sounds, like touch. A loving quality. A little girl singing a love song to her daddy. And I started to have memories. (3) I realized that I never had curtains or drapes in my house. That sound of curtains being scraped on a metal rod has always bothered me. [ILLUSTRATION OMITTED] When I began writing my piece and listening to bell sounds, I found myself remembering being in hospital as a child and hearing the sound of hospital curtains. (4) Five years after I wrote the piece, I started to have memories of my father coming into my bedroom at night and having sex with me as a child. (5) [ILLUSTRATION OMITTED] Suddenly I'm back there in that bed. [ILLUSTRATION OMITTED] [ILLUSTRATION OMITTED] I also have a suspicion that I was sexually abused in hospital and that this is bound up with the sound of those hospital curtains closing. To me, that's the creepiest sound in the piece. (6) [ILLUSTRATION OMITTED] THIS ESSAY BEGINS WITH THE FRAGMENTARY voices and evocative sounds of two contemporary composers who were both sexually abused as children. As we can easily observe, their traumatic childhood memories--so distant and elusive and yet so sensationally raw--emerge primarily through the languages of sounds: sinuous, shimmering string sonorities; rich, echoic timbres of bells and distant voices; and thick, reverberant juxtapositions of acousmatic noise. If we listen carefully, we will also realize that it was the sounds themselves-these strings and bells and metallic scrapes--that triggered these survivors' memories in the first place, that resurrected from the depths of their psyches shocking, devastating sense-memories of violation that seem to have otherwise been cognitively inaccessible, locked away, repressed, dissociated, or forgotten. We can also observe that these composers' sound-triggered recollections present as primarily somatic: their descriptions of the sounds as "cold," "feely, like touch," "white," and "full of pain" suggest that their long-buried memories of trauma are somehow more embodied than cognitively remembered, stored more in the blood and tissue of torso and limb or the deep, elderly smell-regions of the cerebellum than in the swifter, more evolved, and efficiently streamlined neural pathways of the cortex. Their descriptions also suggest that all these sense-memories are deeply intertwined with sound to an almost synaesthetic degree: violins become touch, bells become cold, metallic scrapes become white and painful, memory becomes sensation. (7) In the words of the second composer, "It is like the memories are buried deep inside those muscles, held there in tension ... and now released." (8) How literally can we interpret these sonicsomatic sensations as long-buried, recently recovered memories, as bodily traces of injurious pasts? Can we regard them as actual, physical reenactments of past traumas, as trustworthily engraved on the body as if they had been recorded on tape or camera? Or should we abide a more metaphoric understanding of these testimonies as descriptions of what trauma feels like rather than what it literally is? These two achingly personal stories of abuse and violation illustrate a problem that trauma scholars have been debating for decades, namely, the question of whether it is physiologically possible to involuntarily forget a traumatic experience for years, only to regain memories of the event through accidental or therapeutic exposure to relevant stimuli: smells, songs, touches, colors, sounds. …

We exploit deep combined observations with Spitzer and Chandra of the SWIRE survey in the ELAIS-N1 region, to investigate the nature of the faint X-ray and IR sources in common, to identify AGN/starburst diagnostics, and to study the sources of the X-ray and IR cosmic backgrounds. In the 17'x17' area of the Chandra ACIS-I image there are 3400 SWIRE near-IR sources with 4 sigma detections in at least 2 IRAC bands and 988 sources detected at 24micron with MIPS brighter than 0.1 mJy. Of these, 102 IRAC and 59 MIPS sources have Chandra counterparts, out of a total of 122 X-ray sources present in the area with S(0.5-8 kev)>10^(-15) erg/cm^2/s. We have constructed SEDs for each source using data from the 4 IRAC wavebands, Chandra fluxes, and optical follow-up data in the wavebands U, g', r', i', Z, and H. We fit a number of spectral templates to the SEDs at optical and infrared wavelengths to determine photometric redshifts and spectral categories, and also make use of diagnostics based on the X-ray luminosities, hardness ratios, X-ray to infrared spectral slopes and optical morphologies. Although we have spectroscopic redshifts for only a minority of the Chandra sources, the available SEDs constrain the redshifts for most of the sample sources, which turn out to be typically at 0.5, Comment: Accepted for publication in AJ, March 2005 issue

Very deep near-infrared observations have recently uncovered a significant population of red galaxies at redshifts z>2. These distant red galaxies (DRGs) are efficiently selected by the criterion J-K>2.3. We use Chandra data to examine the X-ray emission from DRGs in the 5'x5' FIRES MS1054-03 field. Two of 40 DRGs with K 1.2x10^43 ergs/s. This fraction is smaller than that inferred from optical and near-IR spectroscopy, probably largely due to strong spectroscopic selection biases. By stacking all undetected DRGs we find that their average X-ray flux in the 0.5-8 keV band is ~4.6x10^-17 ergs/s/cm^2. The detection is only significant in the soft and full energy bands. The mean detection may result from star formation, the presence of low luminosity AGN, or a combination of both. Assuming the detection is due exclusively to star formation, we find an average instantaneous star formation rate of 214 +- 68 (random) +- 73 (systematic) solar masses per year, in excellent agreement with previous results from spectral energy distribution fitting when constant star formation histories are assumed. These results may imply that DRGs contribute significantly to the cosmic star formation rate at z~2.5. However, the mean X-ray flux strictly provides only an upper limit to the star formation rate due to the uncertain contribution of low luminosity, possibly obscured AGNs. Observations at other wavelengths are needed to provide independent estimates of the star formation rate of DRGs.

We present an analysis of two deep (75 ks) Chandra observations of the European Large Area ISO Survey (ELAIS) fields N1 and N2 as the first results from the ELAIS deep X-ray survey. This survey is being conducted in well studied regions with extensive multi-wavelength coverage. Here we present the Chandra source catalogues along with an analysis of source counts, hardness ratios and optical classifications. A total of 233 X-ray point sources are detected in addition to 2 soft extended sources, which are found to be associated with galaxy clusters. An over-density of sources is found in N1 with 30% more sources than N2, which we attribute to large-scale structure. A similar variance is seen between other deep Chandra surveys. The source count statistics reveal an increasing fraction of hard sources at fainter fluxes. The number of galaxy-like counterparts also increases dramatically towards fainter fluxes, consistent with the emergence of a large population of obscured sources., 17 pages, 15 figures, MNRAS accepted; fig 2 corrected, differential counts added, text revised and updated. Further information including electronic source catalogues can be found at http://www.roe.ac.uk/~jcm/edxs/index.html

Emotional Support and Stress Reduction in the Pediatric Dental Setting: Therapy Dog as Part of the Dental Team Dental visits can be stressful not only for the adult but also for the pediatric dental patient. Stress related to dental appointments may be caused by …

We expect the evolution of massive stars to be strongly influenced by mass loss and hence to be sensitive to metallicity. It should be possible to test this "Conti scenario" be comparing the populations of evolved massive stars among the Local Group galaxies, but such investigations have been hampered by incompleteness. In a previous paper, we presented results of a new survey for red supergiants (RSGs) in selected regions of the Local Group galaxies M33, M31, and NGC 6822. In the present paper, we survey eight fields in M33 for Wolf-Rayet stars (WRs), using interference-filter imaging with a CCD to select candidates. Follow-up spectroscopy is used to confirm 22 newly found WR stars, 21 of WN type. We establish that our survey would readily detect WRs as weak-lined as any known, and we conclude that our survey is essentially complete. This survey confirms suspicions that the previous photographic surveys were only 50% complete for WN-type WRs and allows us to combine the data with equally complete samples on other Local Group galaxies. We find that the relative number of WC- and WN-type WRs correlates extremely well with metallicity, varying by a factor of 3 with galactocentric distance within the plane of M33, and continuing the trend to lower and higher metallicity galaxies. The WC/WN ratio within 3 kpc of the sun is slightly above this trend, and we argue that WN stars are underrepresented in this sample. The WC/WN ratio is anomalously high in IC 10, given its low metallicity, and we demonstrate that this is not because of selection effects but is likely caused by IC 10's current status as a starburst system. We examine the spectral properties of WC stars within these galaxies, confirming the previously reported trends that the spectral lines are stronger and broader in regions of lower metallicity. We suggest that the different WC spectral subclasses do not primarily indicate different physical properties for these stars but rather are simply a reflection of the effect that the initial metal abundances has had on the stellar wind structure. Finally, we compare the luminous RSGs with WRs in these galaxies. We find that there is a very strong correlation of the relative numbers of RSGs and WRs with metallicity, in the sense predicted by Maeder, Lequeux, & Azzopardi: at lower metallicities the fraction of luminous (Mbol < -7) RSGs is higher, with a factor of 6 change within the disk of M33 [Δ log (O/H) = 0.35 dex], and a factor of ~10 change from M31 (or the inner portions of M33) to NGC 6822 [Δ log (O/H) = 0.5 dex]. This is easily explained by the Conti scenario in terms of massive stars spending proportionately less of their He-burning lifetimes as RSGs rather than WRs at higher metallicities and hence higher mass-loss rates. Finally, we note that the presence of luminous RSGs and WRs stars is extremely well correlated for the OB associations in M31 and M33: where one finds one, one finds the other. To the extent that an association is strictly coeval, this argues that some stars of 15 M☉ and above indeed do go through both RSG and WR stages. The presence of WR stars of both WN and WC types in the same associations as luminous RSGs further suggests that some WCs, at least, have gone through the RSG phase. We include an Appendix providing a complete catalog of confirmed WR stars in Local Group galaxies beyond the Magellanic Clouds.

Using the Very Large Array, we have observed the H66α radio recombination line (RRL) emission at 1.3 cm and the H52α RRL emission at 7 mm toward the ultracompact H II region M17-UC1 and the nearby arc-shaped structure to the east. The angular resolution of the data is 1''-2''. The compact H II region (deconvolved size ~06 or 0.006 pc) is one of a number of H II regions with broad (≥35 km s-1) RRLs. The line parameters of the nearby arc of ionized emission (hereafter the Arc), about 1'' or 0.01 pc to the east of UC1, are remarkably constant over an area of 165 × 3'' (0.17 pc × 0.03 pc). The derived LTE electron temperature from the H66α line (T) is 6600 K in M17-UC1 and 8200 K in the Arc region. H2O maser emission at 1.3 cm from the region of M17-UC1 was observed in the D array with a beam of 4''. Observations of the H2O maser emission toward M17-UC1 reveal four masers within 30'' of M17-UC1; two of these sources were previously known. We discuss the region near M17-UC1 as an example of shock-induced star formation consisting of a hot, young, massive star surrounded by ionized material, perhaps resulting from a stellar wind outflow. We compare M17-UC1 with the six other known examples of broad-line RRL emission from ultracompact H II regions.

We present a cross-correlation of the European Large Area ISO survey (ELAIS) with the ELAIS Deep X-ray Survey of the N1 and N2 fields. There are 7 Chandra point sources with matches in the ELAIS Final Analysis 15um catalogue, out of a total of 28 extragalactic ISO sources present in the Chandra fields. Five of these are consistent with AGN giving an AGN fraction of ~19 per cent in the 15um flux range 0.8-6 mJy. We have co-added the hard X-ray fluxes of the individually-undetected ISO sources and find a low significance detection consistent with star formation in the remaining population. We combine our point source cross-correlation fraction with the XMM-Newton observations of the Lockman Hole and Chandra observations of the Hubble Deep Field North to constrain source count models of the mid-infrared galaxy population. The low dust-enshrouded AGN fraction in ELAIS implied by the number of cross-identifications between the ELAIS mid-infrared sample and the Chandra point sources is encouraging for the use of mid-infrared surveys to constrain the cosmic star formation history, provided there are not further large undetected populations of Compton-thick AGN., Comment: 9 pages, 6 figures, MNRAS accepted

Hard X-ray surveys have uncovered a large population of heavily obscured AGN. They also reveal a population of quasars with moderate obscuration at both visible and X-ray wavelengths. We use Chandra selected samples of quasars from the ELAIS Deep X-ray Survey (EDXS) and CDF-N to investigate the obscuration towards the nuclei of moderately obscured AGN. We find an inverse correlation between the optical to X-ray flux ratio and the X-ray hardness ratio which can be interpreted as due to obscuration at visible and X-ray wavelengths. We present detailed optical and near-infrared data for a sample of optically-faint (R>23) quasars from the EDXS. These are used to constrain the amount of rest-frame UV/optical reddening towards these quasars. It is found that optically-faint quasars are mostly faint due to obscuration, not because they are intrinsically weak. After correcting for reddening, the optical magnitudes of most of these quasars are similar to the brighter quasars at these X-ray fluxes. Combining with gas column densities inferred from the X-ray observations we consider the gas-to-dust ratios of the obscuring matter. We find that the quasars generally have higher gas-to-dust absorption than that seen in the Milky Way - similar to what has been found for nearby Seyfert galaxies. We consider the possible existence of a large population of X-ray sources which have optical properties of Type 1 (unobscured) quasars, but X-ray properties of Type 2 (obscured) quasars. We show that the observed distribution of optical-to-X-ray flux ratios of quasars at z>1 is skewed to low values compared to the intrinsic distribution..., 12 pages, 10 figures, ApJ, in press

We are undertaking the first systematic study of the prevalence of AGN activity in a large sample of high redshift galaxy clusters. Local clusters contain mainly red elliptical galaxies, and have little or no luminous AGN activity. However, recent studies of some moderate to high redshift clusters have revealed significant numbers of luminous AGN within the cluster. This effect may parallel the Butcher-Oemler effect - the increase in the fraction of blue galaxies in distant clusters compared to local clusters. Our aim is to verify and quantify recent evidence that AGN activity in dense environments increases with redshift, and to evaluate the significance of this effect. As cluster AGN are far less prevalent than field sources, a large sample of over 120 cluster fields at z > 0.1 has been selected from the Chandra archives and is being analysed for excess point sources. The size of the excess, the radial distribution and flux of the sources and the dependence of these on cluster redshift and luminosity will reveal important information about the triggering and fueling of AGN., 2 pages, to appear in proceedings of 'Multi-wavelength AGN surveys', Cozumel, 2003

We explore the relationship between the hard X-ray and sub-mm populations using deep Chandra observations of a large, contiguous SCUBA survey. In agreement with other recent findings, we confirm that the direct overlap is small. Of the 17 sub-mm sources detected in this field at 850 microns, only one is coincident with a Chandra source. The resulting limits imply that the majority of SCUBA sources are not powered by AGN, unless the central engine is obscured by Compton-thick material with a low (1 even if they are purely starburst galaxies. Despite the low detection rate, we find evidence for strong angular clustering between the X-ray and sub-mm populations. The implication is that AGN and SCUBA sources trace the same large-scale structure but do not generally coincide. If bright sub-mm sources represent massive elliptical galaxies in formation, we suggest that (for a given galaxy) the major episode of star-formation must be distinct from the period of observable quasar activity., 12 pages, 8 figures, MNRAS in press. Minor revision, including a comparison with the SED of Arp-220 and an X-ray stacking analysis for the SCUBA sources

The Chandra X-ray Observatory was successfully launched on July 23, 1999, and subsequently began an intensive calibration phase. We present preliminary results from in- flight calibration of the low energy response of the High Resolution Camera Spectroscopic readout (HRC-S) combined with the Low Energy Transmission Grating (LETG) aboard Chandra. These instruments comprise the Low Energy Transmission Grating Spectrometer (LETGS). For this calibration study, we employ a pure hydrogen non-LTE white dwarf emission model (Teff equals 25000 K and log g equals 9.0) for comparison with the Chandra observations of Sirius B. Pre-flight calibration of the LETGS effective area was conducted only at wavelengths shortward of 45 angstroms (E > 0.277 keV). Our Sirius B analysis shows that the HRC-S quantum efficiency (QE) model assumed for longer wavelengths overestimates the effective area on average by a factor of 1.6. We derive a correction to the low energy HRC-S QE model to match the predicted and observed Sirius B spectra over the wavelength range of 45 - 185 angstroms. We make an independent test of our results by comparing a Chandra LETGS observation of HZ 43 with pure hydrogen model atmosphere predictions and find good agreement.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The High Resolution Camera (HRC) is one of two focal plane instruments on the NASA Chandra X-ray Observatory which was successfully launched on July 23, 1999. The Chandra X-ray Observatory was designed to perform high resolution spectroscopy and imaging in the X-ray band of 0.07 to 10 keV. The HRC instrument consists of two detectors, HRC-I for imaging and HRC-S for spectroscopy. Each HRC detector consists of a thin aluminized polyimide blocking filter, a chevron pair of microchannel plates and a crossed grid charge readout. The HRC-I is an approximately 100 X 100 mm detector optimized for high resolution imaging and timing, the HRC-S is an approximately 20 X 300 detector optimized to function as the readout for the Low Energy Transmission Grating. In this paper we discuss the in-flight performance of the HRC-S, and present preliminary analysis of flight calibration data and compare it with the results of the ground calibration and pre-flight predictions. In particular we will compare ground data and in-flight data on detector background, quantum efficiency, spatial resolution, pulse height resolution, and point spread response function.

The Chandra spacecraft has been launched successfully on July 23, 1999. The payload consists of a high resolution X- ray telescope, two imaging detector systems in the focal plane and two transmission gratings. Each one of the two gratings can be put in the beam behind the telescope and the grating spectrometers are optimized for high and low energy, respectively. The Low Energy Transmission Grating Spectrometer consists of three parts: the high-resolution telescope, the transmission grating array and the detector, to read-out the spectral image.