Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM

Transmission spectroscopy1-3 of exoplanets has revealed signatures of water vapour, aerosols and alkali metals in a few dozen exoplanet atmospheres4,5. However, these previous inferences with the Hubble and Spitzer Space Telescopes were hindered by the observations' relatively narrow wavelength range and spectral resolving power, which precluded the unambiguous identification of other chemical species-in particular the primary carbon-bearing molecules6,7. Here we report a broad-wavelength 0.5-5.5 µm atmospheric transmission spectrum of WASP-39b8, a 1,200 K, roughly Saturn-mass, Jupiter-radius exoplanet, measured with the JWST NIRSpec's PRISM mode9 as part of the JWST Transiting Exoplanet Community Early Release Science Team Program10-12. We robustly detect several chemical species at high significance, including Na (19σ), H2O (33σ), CO2 (28σ) and CO (7σ). The non-detection of CH4, combined with a strong CO2 feature, favours atmospheric models with a super-solar atmospheric metallicity. An unanticipated absorption feature at 4 µm is best explained by SO2 (2.7σ), which could be a tracer of atmospheric photochemistry. These observations demonstrate JWST's sensitivity to a rich diversity of exoplanet compositions and chemical processes.

COMPOSITIONAL DIVERSITY IN THE ATMOSPHERES OF HOT NEPTUNES, WITH APPLICATION TO GJ 436b

Neptune-sized extrasolar planets that orbit relatively close to their host stars - often called "hot Neptunes" - are common within the known population of exoplanets and planetary candidates. Similar to our own Uranus and Neptune, inefficient accretion of nebular gas is expected produce hot Neptunes whose masses are dominated by elements heavier than hydrogen and helium. At high atmospheric metallicities of 10-10,000× solar, hot Neptunes will exhibit an interesting continuum of atmospheric compositions, ranging from more Neptune-like, H2-dominated atmospheres to more Venus-like, CO2-dominated atmospheres. We explore the predicted equilibrium and disequilibrium chemistry of generic hot Neptunes and find that the atmospheric composition varies strongly as a function of temperature and bulk atmospheric properties such as metallicity and the C/O ratio. Relatively exotic H2O, CO, CO2, and even O2-dominated atmospheres are possible for hot Neptunes. We apply our models to the case of GJ 436b, where we find that a CO-rich, CH4-poor atmosphere can be a natural consequence of a very high atmospheric metallicity. From comparisons of our results with Spitzer eclipse data for GJ 436b, we conclude that although the spectral fit from the high-metallicity forward models is not quite as good as the best fit obtained from pure retrieval methods, the atmospheric composition predicted by these forward models is more physically and chemically plausible in terms of the relative abundance of major constituents. High-metallicity atmospheres (orders of magnitude in excess of solar) should therefore be considered as a possibility for GJ 436b and other hot Neptunes.

Increasing pneumococcal vaccination rates among residents of long-term--care facilities: provider-based improvement strategies implemented by peer-review organizations in four western states

OBJECTIVE

To evaluate collaborative efforts and intervention strategies by peer-review organizations (PROs) and long-term-care facilities (LTCFs) for improving pneumococcal vaccination rates among residents of LTCFs.

DESIGN

Prospective, before-after quality improvement project.

SETTING

133 LTCFs in Alaska, Idaho, Montana, and Wyoming.

PATIENTS

All residents of participating LTCFs.

METHODS

Baseline pneumococcal vaccination rates were determined by medical-record review, self-reporting by patient or family members, and review of Medicare claims information. Remeasurement of vaccination rates was accomplished from documentation of vaccination of eligible residents by each LTCF.

RESULTS

133 LTCFs with 7,623 residents from Alaska, Idaho, Montana, and Wyoming participated in this quality-improvement project. This accounted for 41% (133/321) of the potential nursing homes and resident population in the participating states. Baseline overall vaccination rates were 40% (3,050/7,589). The overall vaccination rate improved to 75% (5,720/7,623, P<.001). The number of facilities meeting the Healthy People 2000 vaccination goal of 80% improved from 18% (24/133) to 62% (83/133, P<.001). Initial use of chart stickers and implementation of standing orders led to similar increases in vaccination rates, but the standing-order strategy required commitment of fewer PRO resources at a statewide level. Remeasurement of vaccination rates in a subset of participating Idaho LTCFs 1 year after initial vaccination efforts demonstrated a sustained vaccination rate of 70% in facilities enforcing a standing-order policy.

CONCLUSIONS

Simple and straightforward vaccination strategies implemented in LTCFs over a short period of time can have a significant impact on vaccination rates. Collaborative efforts between state PROs and LTCFs enhance implementation of these strategies and can result in the achievement of national vaccination objectives. Standing orders appear to be one intervention effective in sustaining successful vaccination efforts. Regardless of the specific interventions employed, PROs played a significant role in facilitating vaccination program development and intervention implementation.

Standardized surveillance of hemodialysis vascular access infections: 18-month experience at an outpatient, multifacility hemodialysis center

OBJECTIVE

To develop a standardized surveillance system for monitoring hemodialysis vascular-access infections in order to compare infection rates between outpatient sites and to assess the effectiveness of infection control interventions.

DESIGN

Prospective descriptive analysis of incidence infection rates.

SETTING

An outpatient hemodialysis center with facilities in Idaho and Oregon.

PATIENTS

All outpatients receiving chronic outpatient hemodialysis.

RESULTS

There were 38,096 hemodialysis sessions (31,603 via permanent fistulae or grafts, 5,060 via permanent tunneled central catheters, and 1,433 via temporary catheters) during an 18-month study period in 1997 to 1998. We identified 176 total infections, for a rate of 4.62/1,000 dialysis sessions (ds). Of the 176, 80 involved permanent fistulae or grafts (2.53/1,000 ds), 69 involved permanent tunneled central catheter infections (13.64/1,000 ds), and 27 involved temporary catheter infections (18.84/1,000 ds). There were 35 blood-stream infections (0.92/1,000 ds) and 10 episodes of clinical sepsis (0.26 /1,000 ds). One hundred thirty-one vascular-site infections without bacteremia were identified (3.44/1,000 ds), including 65 permanent fistulae or graft infections (2.06/1,000 ds), 42 permanent tunneled central catheter infections (8.3/1,000 ds), and 24 temporary catheter infections (16.75/1,000 ds).

CONCLUSIONS

Infection rates were highest among temporary catheters and lowest among permanent native arteriovenous fistulae or synthetic grafts. This represents the first report of extensive incidence data on hemodialysis vascular access infections and represents a standardized surveillance and data-collection system that could be implemented in hemodialysis facilities to allow for reliable data comparison and benchmarking.

Regional data set of infection rates for long-term care facilities: description of a valuable benchmarking tool

BACKGROUND

Surveillance for nosocomial infections has been clearly established as a key element of all infection control programs. Surveillance programs in long-term care facilities (LTCFs) have been described, but published infection rates vary widely depending on the type of facility studied, nature of resident population, definitions used for LTCF-acquired infections, and type of data analysis. The aim of this initial study was to create a standardized regional data set of infection rates that could provide an external benchmark for interfacility comparison.

METHODS

The study included 6 LTCFs in close geographic proximity with similar patient populations. Surveillance in each facility was conducted by a licensed nurse supervised by an infectious diseases physician. Standard definitions for infections and uniform reporting forms were used. Data were pooled in an aggregate cumulative fashion, and data analysis was patterned after the National Nosocomial Infection Surveillance System.

RESULTS

The data set consisted of 328,065 resident-days of care during 30 months, with a total of 1252 infections for a pooled mean rate of 3.82 infections per 1000 resident-days of care. Infections for specific categories were 496 urinary tract infections (rate 1.51), 376 respiratory tract infections (rate 1.15), 88 gastroenteritis infections (rate 0.27), 283 skin and soft tissue infections (rate 0.86), 2 bloodstream infections (rate 0.06), and 3 unexplained febrile illnesses (rate 0. 09). Data analysis for comparison included interfacility means +/-2 standard deviations and percentiles of distribution.

CONCLUSIONS

A regional data set of infection rates for LTCFs allowed for meaningful interfacility comparison of overall and specific endemic rates and is a valuable benchmarking tool for participating facilities.

Enterococcal meningitis: report of four cases and review

Enterococci, a significant cause of human infections outside of the CNS, have only rarely been documented to cause meningitis. To add to our understanding of this uncommon infectious process, we report our experience with four patients with enterococcal meningitis and summarize findings associated with 28 additional cases found in the medical literature. The majority of the adult patients with this condition had coexistent chronic underlying illnesses and were frequently exposed to immunosuppressive therapy. In addition, more than one-third of these patients had experienced CNS trauma or surgery, and 31% had an infection with enterococci at a site other than the CNS. Pediatric patients predominantly had underlying CNS pathology primarily consisting of neural tube defects or hydrocephalus. Primary meningitis occurred in 25% of pediatric patients, with most of these episodes occurring in neonates. Most patients presented with expected signs, symptoms, and physical features of acute bacterial meningitis and had typical CSF abnormalities, including leukocytic pleocytosis, elevated protein levels, and hypoglycorrhachia. The overall mortality rate among patients with enterococcal meningitis was 13%. The small number of patients in this review failed to demonstrate a definite difference in mortality among patients treated with cell wall-active agents alone vs. those treated with combination therapy with an aminoglycoside, although studies of patients with other complicated enterococcal infections suggest that combination therapy would be preferable.

Fodrin and band 4.1 in a plasma membrane-associated fraction of human neutrophils

Erythrocytes possess a well-characterized submembranous filamentous network which interacts with transmembrane glycoproteins and is composed primarily of spectrin, ankyrin, band 4.1, and short actin filaments. An analogous structure was recently described in platelets. Human polymorphonuclear leukocytes (PMNs) were examined for the presence and plasma membrane association of similar proteins. Isolated PMNs, free of contamination with erythrocytes or platelets, were disrupted by nitrogen cavitation and separated into subcellular organelles on a discontinuous Percoll gradient. Detergent lysates of plasma membrane vesicles, but not azurophilic or specific granules, contained insoluble actin filaments and associated proteins. Immunoblots of detergent-insoluble plasma membrane fractions contained proteins recognized by antibodies to brain fodrin and erythrocyte band 4.1, whereas blots probed with antibodies to erythrocyte spectrin and ankyrin were negative. Fodrin and band 4.1 were not detected in granule fractions, but some fodrin was present in the cytosol. The association of proteins related to fodrin and band 4.1 with the plasma membrane suggests that PMNs contain a submembranous skeleton structurally analogous to that of erythrocytes and platelets. The specific function of these proteins and their structural organization in human PMNs await further study.

The neutrophil glycoprotein Mo1 is an integral membrane protein of plasma membranes and specific granules

The glycoprotein Mo1 has previously been demonstrated to be on the cell surface and in the specific granule fraction of neutrophils and to be translocated to the cell surface during degranulation. It is not known, however, whether Mo1 is an integral membrane protein or a soluble, intragranular constituent loosely associated with the specific granule membrane. Purified neutrophils were disrupted by nitrogen cavitation and separated on Percoll density gradients into four fractions enriched for azurophilic granules, specific granules, plasma membrane, and cytosol, respectively. The glycoproteins in these fractions were labeled with 3H-borohydride reduction, extracted with Triton X-114, and immunoprecipitated with 60.3, an anti-Mo1 monoclonal antibody Mo1 was detected only in the specific granule and plasma membrane fractions and partitioned exclusively into the detergent-rich fraction consistent with Mo1 being an integral membrane protein. In addition, treatment of specific granule membranes with a high salt, high urea buffer to remove absorbed or peripheral proteins failed to dissociate Mo1. These data support the hypothesis that Mo1 is an integral membrane protein of plasma and specific granule membranes in human neutrophils.

The neutrophil glycoprotein Mo1 is an integral membrane protein of plasma membranes and specific granules

The glycoprotein Mo1 has previously been demonstrated to be on the cell surface and in the specific granule fraction of neutrophils and to be translocated to the cell surface during degranulation. It is not known, however, whether Mo1 is an integral membrane protein or a soluble, intragranular constituent loosely associated with the specific granule membrane. Purified neutrophils were disrupted by nitrogen cavitation and separated on Percoll density gradients into four fractions enriched for azurophilic granules, specific granules, plasma membrane, and cytosol, respectively. The glycoproteins in these fractions were labeled with 3H-borohydride reduction, extracted with Triton X-114, and immunoprecipitated with 60.3, an anti-Mo1 monoclonal antibody Mo1 was detected only in the specific granule and plasma membrane fractions and partitioned exclusively into the detergent-rich fraction consistent with Mo1 being an integral membrane protein. In addition, treatment of specific granule membranes with a high salt, high urea buffer to remove absorbed or peripheral proteins failed to dissociate Mo1. These data support the hypothesis that Mo1 is an integral membrane protein of plasma and specific granule membranes in human neutrophils.

Eucaloric substitution of medium chain triglycerides for dietary long chain fatty acids in acquired total lipodystrophy: effects on hyperlipoproteinemia and endogenous insulin resistance

Previous studies have suggested that reduction of dietary fat intake, with or without caloric restriction, may lead to improvement in certain of the characteristic abnormalities that accompany total lipodystrophy (TLD). We have studied the effects of eucaloric medium chain triglyceride (MCT) substitution for dietary long chain fatty acids in a patient with acquired total lipodystrophy and unusual somatic and visceral anomalies. The patient exhibited insulin resistance, carbohydrate intolerance, striking fasting- and glucose-stimulated hyperinsulinemia, hyperglucagonemia, type V hyperlipoproteinemia, and lipoprotein lipase deficiency on a normal diet. Improvement in chylomicronemia, hypertriglyceridemia, and xanthomatosis occurred during eucaloric MCT substitution. Carbohydrate intolerance decreased and fasting immunoreactive glucagon and insulin concentrations fell 37% and 83%, respectively. Plasma triglyceride polyunsaturated fatty acid concentrations decreased to very low levels. With long term MCT feeding supplemented by polyunsaturated fatty acids, hepatomegaly has gradually decreased, while body weight has remained stable. The patient has not yet required insulin therapy. These observations suggest that the abnormalities in carbohydrate metabolism are closely linked to, and perhaps dependent on, the abnormalities in lipoprotein transport in TLD. Long chain triglyceride restriction and MCT supplementation should be attempted in additional patients with the features of TLD to determine whether this is a generally effective therapeutic approach.