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Oxidation of sulfur dioxide (SO2) in cloud water by reaction with ozone is an important sulfate aerosol formation mechanism and strongly dependent on the acidity of cloud water. Decadal reductions in Northern Hemisphere sulfur emissions have contributed to higher cloud water pH, thereby altering sulfate formation rates. Here we use a global composition‐climate model to show that changes in cloud water pH over the 1970–2009 period strongly affects the aerosol particle size distribution, cloud condensation nuclei concentrations, and the magnitude of aerosol radiative forcing. The simulated all‐sky aerosol radiative forcing (1970–2009) over the North Atlantic is +1.2 W m−2if pH remains constant at 5.0, as in many climate models. However, the forcing increases to +5.2 W m−2if pH is assumed to increase by 1.0 unit over this period. Global composition climate models need to account for variations in cloud water pH to improve the representation of sulfate aerosol formation and aerosol radiative effects. Particles in the atmosphere (aerosols) can be harmful to human health at the surface and also affect the Earth's climate. Sulfate is a major component of atmospheric aerosols. It is formed from chemical reactions involving sulfur dioxide, which has large man‐made sources in the energy and industrial sectors. This study investigates the sensitivity of sulfate aerosol formation in clouds to the assumed acidity of the cloud water. Large changes in man‐made emissions over the Northern Hemisphere in the last 30 years have altered the acidity of cloud water. Here we used climate model simulations that include a representation of aerosols and chemistry to investigate the effect of changes in cloud water acidity on sulfate aerosol formation between 1970 and 2009. Our analysis shows that changes in the acidity of cloud water has a strong effect on the properties of aerosols and how they interact with the Earth's radiative balance. The impact is shown to be particularly important for cloudy regions like the North Atlantic that are sensitive to changes in aerosols. The results highlight that the impact of changes in cloud water acidity on aerosols should be included within climate models to improve our representation of aerosols and their interaction with climate. Increases in assumed cloud water pH can improve simulation of sulfate aerosolsAerosol radiative forcing over the last 40 years is sensitive to the value of cloud water pHGlobal composition climate models assuming a fixed value of cloud water pH do not fully account for recent aerosol radiative forcing

Understanding how air pollution events may change in the future is of key importance to decision makers. Multi‐model intercomparison projects focusing on atmospheric chemistry and air quality have been performed to inform the latest IPCC assessments. Future anthropogenic emission changes have generally been the foci of such model experiments, envisaged as the dominant driver of future atmospheric composition. The latest model assessments such as AerChemMIP utilize multi‐model ensembles but also have limited individual model ensembles which permit different sources of uncertainty to be characterized. The recent study by Fiore et al. (2022, https://doi.org/10.1029/2021JD035985) specifically considers a multi‐model and multi‐member ensemble approach. It adds to the quantification of uncertainty in future projections through delineating uncertainty due to model diversity and due to internal or natural climate variability within the climate system, for mean and high PM2.5 air pollution events over the Eastern USA in the 21st century. Exploring the separate roles of internal climate variability and model diversity adds further value to the important research issue of quantifying how future anthropogenic climate change impacts air quality. Future multi‐model intercomparisons need to balance the additional knowledge gained from research into understanding multiple sources of uncertainty that can inform decision making vs. the resource costs of performing these experiments using Earth System Models with interactive chemistry. Climate change projections are inherently uncertain. There are several main sources of uncertainty that arise from: (a) future changes in emissions related to human activity, (b) models responding differently to climate change and/or emission changes, (c) natural variability in the climate system. To determine the impact of these sources of uncertainty on future air quality, complex Earth System Models are required which are extremely resource intensive. Therefore, most studies to date have not been able to evaluate all the relevant sources of uncertainty because multiple models and multiple simulations are required to do this. The study by Fiore et al. (2022, https://doi.org/10.1029/2021JD035985) uses results from multiple models and multiple simulations to explore uncertainty due to different model responses and to natural climate variability. In doing so, this study provides a more robust assessment of climate change impacts on air pollution events in the 21st century for the Eastern USA and sets out a framework for understanding how uncertainty impacts on future projections of atmospheric composition. Several main sources of uncertainty impact projections of future air qualityEarth System Models with interactive chemistry are computationally expensive, hence understanding which sources of uncertainty are most important is crucialThe capability to explore and partition the uncertainty in multi‐model responses for future air quality assessments is being realized Several main sources of uncertainty impact projections of future air quality Earth System Models with interactive chemistry are computationally expensive, hence understanding which sources of uncertainty are most important is crucial The capability to explore and partition the uncertainty in multi‐model responses for future air quality assessments is being realized

On average, about 25% of male and 50% of female enlisted recruits sustain one or more injuries during basic training. Because data on military officer populations are sparse, this study investigated injury incidence, injury rates, and modified duty days that occurred during Marine Corps officer basic training (6 weeks in length). Subjects were 480 officer candidates (including 30 females) undergoing training at Quantico, Virginia. The cumulative injury incidence (one or more injuries) was 60.8%, and the injury rate was 3.9 per 1,000 candidate hours of training. There were 378 primary injury encounters (first visit for a specific injury). The highest injury rates occurred during weeks 2, 3, and 6. Male injury categories with the highest rates (injuries per 100 trainees per 1,000 training hours) were blisters (0.68), sprains (0.58), and bone stress reactions (0.40). The highest injury rates in females were for bone stress reactions (1.35). On average, a total of 3.1% of training days constituted modified duty for each candidate. This study provides basic descriptive injury data for this unique military population that can assist in future planning for injury management and preventive interventional strategies.

Fasciola hepaticainfection of cattle and sheep is an important cause of clinical disease and production losses, and is controlled at present by a combination of chemotherapy and management measures. However, the prospects for the control ofF. hepaticainfection by vaccination are good, and we have previously shown substantial protection of cattle against experimental challenge infection following immunisation with a combination of the purified fluke-derived enzymes cathepsin L1 (CATL1), cathepsin L2 (CATL2) and fluke-derived Hb fraction (FHB). This and other recent studies have also demonstrated fundamental differences between protective and non-protective immune responses to liver fluke infection. In this present study we have further analysed the response of animals to liver fluke challenge following experimental vaccination. Calves were vaccinated with eitherCATL2 plusFHB, orCATL1 plusCATL2. Partial protection against challenge infection was achieved in both vaccinated groups, with the greatest level of protection (55 per cent reduction in fluke burdens) recorded in the group vaccinated withCATL1 plusCATL2. This latter group also showed the greater level of lymphocyte proliferation and the greater production of γ-INF in response to stimulation with fluke antigen in vitro following challenge. These results are significant in our attempts to characterise the elements within the immune response to vaccination which are protective.

Morbid obesity is often associated with cardiac dilatation and left ventricular dysfunction. The present study investigated whether a similar relationship exists between mild and moderate obesity and left ventricular reserve function in 28 middle aged and older men (58.6± 6.1 years, mean± SD). Subjects had a body mass index of 26.4± 2.9 kg/m2, a percent body fat determined by hydrodensitometry ranging from 9.5% to 33.8%, and were carefully screened to exclude cardiovascular disease. Left ventricular function was assessed by gated blood pool scans at rest and during exhaustive upright cycle exercise. There were no significant relationships between resting or exercise cardiac volumes or ejection fraction with percent bodyfat; however, peak work rate/kg correlated inversely with percent body fat (r=- 0.68, p<0.0001). Heart rate reserve, defined as heart rate at peak work rate minus resting heart rate, declined significantly with increasing percent body fat (r=- 0.47, p=0.01). End diastolic volume index reserve also tended to decline with increasing percent body fat, but stroke volume index and cardiac index reserve were maintained because the decrease in end systolic volume index from rest to maximal exercise was greatest in those subjects with highest percent body fat (r=- 0.41, p=0.03). Therefore, rest and exercise left ventricular function are not related to percent body fat in healthy older men. However, older more obese men have a smaller increase in heart rate and end diastolic volume and a greater decrease in end systolic volumefrom rest to peak effort as a mechanism to augment exercise cardiac output. (Aging Clin. Exp. Res. 6: 257–265, 1994)

Although exercise-induced supraventricular arrhythmias (EISVA) increase with advancing age, it is unclear whether age-associated changes in cardiac structure or function play a major role in this increase. To address this question, we examined the relationship between M-mode echocardiographic variables and EISVA occurring during maximal treadmill exercise in 366 healthy volunteers aged 20 to 90 years from the Baltimore Longitudinal Study of Aging. Simple (i.e., isolated) EISVA were detected in 69 subjects (19%), and complex EISVA (i.e., comprising >10% of beats in any minute or occurring in runs) in another 29 subjects (8%). Univariate predictors of any EISVA, whether simple or complex, were older age (p<0.0001), male gender (p<0.05), greater left atrial size (p<0.01), left ventricular mass index (p<0.0001), interventricular septal thickness (ps0.001), isovolumic relaxation time (p<0.01), atrial filling fraction (p<0.01), reduced mitral E-F closure slope (p<0.001), peak E velocity (p<0.02), and peak E/A ratio (p<0.0001). Lesser exercise duration (p<0.01), lower maximal heart rate (p<0.0001), and higher peak systolic and diastolic blood pressures (p<0.001) were also associated with EISVA. However, by multiple logistic regression analysis, age (p<0.0001) was the only independent predictor of any EISVA. Univariate predictors of complex EISVA were greater age (p<0.0001), atrial filling fraction (p<0.001), diastolic blood pressure (p<0.05), lesser mitral E-F slope (p<0.004), exercise duration (p<0.005) and maximal heart rate (p<0.01). However, only age (p<0.0001) independently predicted complex EISVA. Thus, in healthy volunteers undergoing maximal treadmill exercise, EISVA are associated with greater left ventricular wall thickness, reduced early diastolic performance, diminished exercise capacity and elevated exercise blood pressure. However, none of these variables are independent predictors of EISVA over and above the powerful effect of age.

Immunoreactive secretin (IRS) and immunoreactive insulin (IRI) levels were measured in humans and dogs following the intraduodenal instillation of hydrochloric acid. IRS levels rose after acid in both instances, but a concomitant rise in peripheral IRI levels was not noted. Premedication of the humans with Scopolamine prevented a rise of IRS in the human subjects. It is concluded that the endogenous release of IRS alone does not result in increased IRI levels in peripheral blood and that IRS release may be under vagal control.

In a recent article, Plotz1 reported twenty-one cases of infestation with Diphyllobothrium latum, the broad fish tapeworm, occurring in New York City. Five of the patients were native-born Americans. With the increasing number of native cases appearing in cities located at some distance from the endemic areas, it is important to study the sources of the disease. Three cases in New York City, reports of which had not been published, were studied with special reference to their common source of infestation. CASE 1. —J. K., a Jewish girl, aged 5 years, who was born and had always lived in New York City, came to the Presbyterian Hospital, July 11, 1927, because of nausea, vomiting, poor appetite, and the passing of segments of tapeworm for the past six months. She was also troubled with bronchitis. A stool examination showed ova of Diphyllobothrium latum. There was no anemia. Following treatment with

THE ecology of the terrestrial Enchytraeidae has been neglected mainly because of the lack of an adequate technique for assessing population size and partly because of taxonomic difficulties. Recently, Overgaard Nielsen1has described a method for the large-scale extraction of these worms from soil. This consists of heating soil cores in an earthenware cylinder over a water-bath, and driving the worms upwards into a layer of cooled sand on top of the soil. The enchytraeids are then recovered by washing from the sand.

NATURAL populations of the common enchytraeid worm Lumbricillus lineatus Müll., occurring in decaying seaweed, contain diploid (2n= 26) and triploid (3n = 39) individuals. The Enchytraeidae are normally hermaphrodite but the triploid form of L. lineatus reproduces parthenogenetically and is distinguishable from the diploid type by the absence of seminal vesicles. Spermatogenesis in the partheno-genetic form does not proceed beyond the spermatid stage and no mature spermatozoa are produced1. In spite of this, the spermathecæ of triploid worms from natural populations always contain spermatozoa. Experiments were designed to determine the origin of these spermatozoa as well as their possible role in the activation of cleavage in triploid eggs. The triploid form will be referred to as L. lineatus 3 × and the diploid as L. lineatus 2 ×.