Ancient eruptions of Eta Carinae: A tale written in proper motions

We analyze eight epochs of Hubble Space Telescope H$\alpha$+[N II] imaging of Eta Carinae's outer ejecta. Proper motions of nearly 800 knots reveal that the detected ejecta are divided into three apparent age groups, dating to around 1250 A.D., to around 1550 A.D., and to during or shortly before the Great Eruption of the 1840s. Ejecta from these groups reside in different locations and provide a firm constraint that Eta Car experienced multiple major eruptions prior to the 19th century. The 1250 and 1550 events did not share the same axisymmetry as the Homunculus; the 1250 event was particularly asymmetric, even one-sided. In addition, the ejecta in the S ridge, which have been associated with the Great Eruption, appear to predate the ejection of the Homunculus by several decades. We detect essentially ballistic expansion across multiple epochs. We find no evidence for large-scale deceleration of the observed knots that could power the soft X-ray shell by plowing into surrounding material, suggesting that the observed X-rays arise instead from fast, rarefied ejecta from the 1840s overtaking the older dense knots. Early deceleration and subsequent coasting cannot explain the origin of the older outer ejecta---significant episodic mass loss prior to the 19th century is required. The timescale and geometry of the past eruptions provide important constraints for any theoretical physical mechanisms driving Eta Car's behavior. Non-repeating mechanisms such as the merger of a close binary in a triple system would require additional complexities to explain the observations.Comment: 14 pages, 11 figures, accepted for publication in MNRA

Proper motions of collimated jets from intermediate-mass protostars in the Carina Nebula

We present proper motion measurements of 37 jets and HH objects in the Carina Nebula measured in two epochs of H$\alpha$ images obtained $\sim 10$ yrs apart with HST/ACS. Transverse velocities in all but one jet are faster than $\gtrsim 25$ km s$^{-1}$, confirming that the jet-like H$\alpha$ features identified by Smith et al. (2010) trace outflowing gas. Proper motions constrain the location of the jet-driving source and provide kinematic confirmation of the intermediate-mass protostars that we identify for 20/37 jets. Jet velocities do not correlate with the estimated protostar mass and embedded driving sources do not have slower jets. Instead, transverse velocities (median $\sim 75$ km s$^{-1}$) are similar to those in jets from low-mass stars. Assuming a constant velocity since launch, we compute jet dynamical ages (median $\sim 10^4$ yr). If continuous emission from inner jets traces the duration of the most recent accretion bursts, then these episodes are sustained longer (median $\sim 700$ yr) than the typical decay time of an FU Orionis outburst. These jets can carry appreciable momentum that may be injected into the surrounding environment. The resulting outflow force, $dP/dt$, lies between that measured in low- and high-mass sources, despite the very different observational tracers used. Smooth scaling of the outflow force argues for a common physical process underlying outflows from protostars of all masses. This latest kinematic result adds to a growing body of evidence that intermediate-mass star formation proceeds like a scaled-up version of the formation of low-mass stars.Comment: accepted to MNRAS, 29 pages, 30 figures, 3 table

Proper motions of five OB stars with candidate dusty bow shocks in the Carina Nebula

We constrain the proper motions of five OB stars associated with candidate stellar wind bow shocks in the Carina Nebula using HST ACS imaging over 9--10 year baselines. These proper motions allow us to directly compare each star's motion to the orientation of its candidate bow shock. Although these stars are saturated in our imaging, we assess their motion by the shifts required to minimize residuals in their Airy rings. The results limit the direction of each star's motion to sectors less than 90 degrees wide. None of the five stars are moving away from the Carina Nebula's central clusters as runaway stars would be, confirming that a candidate bow shock is not necessarily indicative of a runaway star. Two of the five stars are moving tangentially relative to the orientation of their candidate bow shocks, both of which point at the OB cluster Trumpler 14. In these cases, the large-scale flow of the interstellar medium, powered by feedback from the cluster, appears to dominate over the motion of the star in producing the observed candidate bow shock. The remaining three stars all have some component of motion toward the central clusters, meaning that we cannot distinguish whether their candidate bow shocks are indicators of stellar motion, of the flow of ambient gas, or of density gradients in their surroundings. In addition, these stars' lack of outward motion hints that the distributed massive-star population in Carina's South Pillars region formed in place, rather than migrating out from the association's central clusters.Comment: 13 pages, 5 figures, accepted for publication in MNRA

Induction of strain-transcendent antibodies to placental-type isolates with VAR2CSA DBL3 or DBL5 recombinant proteins

<p>Abstract</p> <p>Background</p> <p>Pregnancy associated malaria is a severe clinical syndrome associated with sequestration of <it>Plasmodium falciparum</it>-infected erythrocytes in the placenta. Placental binding is mediated by VAR2CSA, which adheres to chondroitin sulphate A (CSA). VAR2CSA is a large and polymorphic protein that has six Duffy binding-like (DBL) domains. There is still limited understanding as to how effective individual VAR2CSA domains are at generating inhibitory antibodies or the number of domain variants needed for universal vaccine coverage.</p> <p>Methods</p> <p>To investigate the immunogenic properties of single domain VAR2CSA recombinant proteins, rats or rabbits were immunized with five of the six VAR2CSA domains produced in <it>Pichia pastoris</it>. Immune plasma was analysed against a geographically diverse panel of CSA-binding lab lines to assess antibody breadth and inhibitory activity.</p> <p>Results</p> <p>Of the five domains, DBL3, and to a lesser extent DBL5, induced antibodies that cross-reacted on five diverse CSA-binding parasite lines by flow cytometry. By comparison, anti-DBL6 antibodies were highly strain-specific and anti-DBL1 and anti-DBL4 antibodies were poorly reactive by flow cytometry. From this series of recombinant proteins, adhesion-blocking activity was restricted to a single rat immunized against a DBL4 recombinant protein.</p> <p>Conclusions</p> <p>Single domain VAR2CSA recombinant proteins produced in <it>P. pastoris </it>had limited efficacy in eliciting adhesion blocking antibody responses, but VAR2CSA DBL3 and DBL5 domains contain strain-transcendent epitopes that can be targeted by vaccination and may have application for vaccine development.</p

Screening for Elder Mistreatment among Older Adults Seeking Legal Assistance Services

Introduction: The aging population is a rapidly growing demographic in the United States. Isolation, limited autonomy, and declining physical and mental health render many older adults vulnerable to elder mistreatment (EM). The purpose of this study was to assess the prevalence and correlates of EM among a sample of older adults using legal assistance services in Atlanta, Georgia. Methods: Researchers administered surveys to consenting older adults (aged 60þ) in 5 metro Atlanta community centers that hosted legal assistance information sessions as part of the Elderly Legal Assistance Program. The surveys screened for risk factors and prevalence of EM risk using valid and reliable measures and included additional questions regarding demographics characteristics and healthcare use behaviors. Results: Surveys were completed by 112 participants. Findings reveal that 32 (28.6%) respondents met the criteria for elder abuse / neglect risk; 17 (15.2%) respondents met criteria for depression; and 105 (93.7%) had visited a healthcare provider during the past 6 months. Conclusion: The rates of EM risk in this sample were higher than those previously reported in research. Findings support continued examination of unique risks that may be present among older adults who may be possibly facing legal issues. Additionally, the reported frequency of healthcare visits among participants reveals a promising opportunity to examine development of a more widespread EM screening approach to be conducted in non-emergency settings. Interdisciplinary collaboration is required to inform screening approaches that account for complexities that EM cases present. [West J Emerg Med. 2013;14(4):309–315.] INTRODUCTIO

Mental Health Assessments in ICU and Acute Care

The purpose of our critically appraised topic is to provide a brief summary of assessments that may be relevant to the burn unit or ICU setting, including their validity, reliability, specificity, sensitivity, and limitations. We had a total of eight articles with the following study designs: Systematic Review (2 articles), Longitudinal Study (1 article), Comparative Analysis (1 article), Correlational Analysis (2 articles) and Methodological (2 articles). These articles looked at the reliability, validity, specificity, and sensitivity of the following assessments: Abbreviated Burn Specific Anxiety Scale (A-BSPAS), Beck Depression Inventory-II, Brief Coping Orientation to Problems Experience (B-COPE), Concise Mental Health Checklist (CMHC-9), Confusion Assessment Method for Intensive Care Units (CAM-ICU), Startle, Physiological arousal, Anger, and Numbness (SPAN), Trauma Screening Questionnaire (TSQ), The Confusion Assessment Method (CAM), and Wound-Quality of Life. We found the following assessments applicable for the burn unit or ICU: CAM, B-COPE, CAM-ICU Flowsheet. Our clinical recommendations are for these assessments to be used to perform a screening of the client\u27s mental state, which will help the Occupational therapist develop and plan interventions

The Effects of Lower Body Positive Pressure Treadmill Running on Acute Femoral Cartilage Deformation

Purpose: Examine and compare the acute response of femoral cartilage in healthy individuals after running at full bodyweight (BW) (100%) and 80% BW on a lower body positive pressure treadmill. Methods: Crossover study consisted of 20 total healthy participants (10 males, 10 females). Femoral cartilage width was assessed using ultrasonography before and after the assigned running conditions. The control condition consisted of running at 6mph for 30 minutes at 100% BW, while the experimental condition consisted of running at 6mph for 30 minutes at 80% BW. Each participant ran both BW conditions, exactly one week apart. The order of conditions was randomly assigned to each participant. All running conditions were completed on the same AlterG Via X treadmill. Results: A significant reduction in cartilage width was found in both the right (p=0.001) and left (p=0.016) knees after running at 100% BW. Baseline cartilage measurements were comparative prior to each running condition and between limbs. There were no significant differences between limbs for either running condition. A significant reduction in cartilage width was seen after running at 80% body weight only in the right lateral compartment (p=0.006). Cartilage showed greater deformation after 100% BW than 80% BW in right (p=0.033) and left (p=0.011) knees. Conclusions: Cartilage thickness change proved to be lower after 80% BW running compared to 100% BW, which could have implications for long term cartilage health and future research into anti-gravity running

Social Functioning in Children with Brain Insult

Social dysfunction is commonly reported by survivors of brain insult, and is often rated as the most debilitating of all sequelae, impacting on many areas of daily life, as well as overall quality of life. Within the early brain insult (EBI) literature, physical and cognitive domains have been of primary interest and social skills have received scant attention. As a result it remains unclear how common these problems are, and whether factors predictive of recovery (insult severity, lesion location, age at insult, environment) in other functional domains (motor, speech, cognition) also contribute to social outcome. This study compared social outcomes for children sustaining EBI at different times from gestation to late childhood to determine whether EBI was associated with an increased risk of problems. Children with focal brain insults were categorized according to timing of brain insult: (i) Congenital (n = 38): EBI: first–second trimester; (ii) Perinatal (n = 33); EBI: third trimester to 1-month post-natal; (iii) Infancy (n = 23): EBI: 2 months–2 years post-birth; (iv) Preschool (n = 19): EBI: 3–6 years; (v) Middle Childhood (n = 31): EBI: 7–9 years; and (vi) Late Childhood (n = 19): EBI: after age 10. Children's teachers completed questionnaires measuring social function (Strengths and Difficulties Questionnaire, Walker–McConnell Scale of Social Competence and School Adjustment). Results showed that children with EBI were at increased risk for social impairment compared to normative expectations. EBI before age 2 years was associated with most significant social impairment, while children with EBI in the preschool years and in late childhood recorded scores closer to normal. Lesion location and laterality were not predictive of social outcome, and nor was social risk. In contrast, presence of disability (seizures) and family function were shown to contribute to aspects of social function

Proximity Effects and Nonequilibrium Superconductivity in Transition-Edge Sensors

We have recently shown that normal-metal/superconductor (N/S) bilayer TESs (superconducting Transition-Edge Sensors) exhibit weak-link behavior.1 Here we extend our understanding to include TESs with added noise-mitigating normal-metal structures (N structures). We find TESs with added Au structures also exhibit weak-link behavior as evidenced by exponential temperature dependence of the critical current and Josephson-like oscillations of the critical current with applied magnetic field. We explain our results in terms of an effect converse to the longitudinal proximity effect (LoPE)1, the lateral inverse proximity effect (LaiPE), for which the order parameter in the N/S bilayer is reduced due to the neighboring N structures. Resistance and critical current measurements are presented as a function of temperature and magnetic field taken on square Mo/Au bilayer TESs with lengths ranging from 8 to 130 {\mu}m with and without added N structures. We observe the inverse proximity effect on the bilayer over in-plane distances many tens of microns and find the transition shifts to lower temperatures scale approximately as the inverse square of the in- plane N-structure separation distance, without appreciable broadening of the transition width. We also present evidence for nonequilbrium superconductivity and estimate a quasiparticle lifetime of 1.8 \times 10-10 s for the bilayer. The LoPE model is also used to explain the increased conductivity at temperatures above the bilayer's steep resistive transition.Comment: 10 pages, 8 figure