The transfer of water from a swimming pool to the treatment location is key in determining the effectiveness of water treatment by filtration in removing turbidity and managing the risk from ...particulate material, including microbial pathogens, such as Cryptosporidium spp. A key recommendation for pool operators when dealing with an accidental faecal release (the likely main source of high Cryptosporidium oocyst concentrations in pools) is that the pool water should be filtered for at least six turnover cycles prior to use. This paper briefly outlines the theoretical basis of what has become known as the Gage–Bidwell Law of Dilution, which provides a basis for this recommendation, and extends the idea to account for the impact of filter efficiency. The Gage–Bidwell Law reveals that for each pool turnover 63% of the water resident in the pool at the start of the turnover period will have been recirculated. Building on this, we demonstrate that both filter efficiency and water-turnover time are important in determining filtration effectiveness and can be combined through a single parameter we term ‘particle-turnover’. We consider the implications of the Gage–Bidwell Law (as referred to in the original 1926 paper) for the dynamics of the ‘dirt’ content of pool water, whether in terms of a specific particle size range (e.g., Cryptosporidium oocysts) or turbidity.
We describe in detail the instrumentation and calibrations used in the Atmospheric Lifetime Experiment (ALE), the Global Atmospheric Gases Experiment (GAGE), and the Advanced Global Atmospheric Gases ...Experiment (AGAGE) and present a history of the majority of the anthropogenic ozone‐depleting and climate‐forcing gases in air based on these experiments. Beginning in 1978, these three successive automated high‐frequency in situ experiments have documented the long‐term behavior of the measured concentrations of these gases over the past 20 years, and show both the evolution of latitudinal gradients and the high‐frequency variability due to sources and circulation. We provide estimates of the long‐term trends in total chlorine contained in long‐lived halocarbons involved in ozone depletion. We summarize interpretations of these measurements using inverse methods to determine trace gas lifetimes and emissions. Finally, we provide a combined observational and modeled reconstruction of the evolution of chlorocarbons by latitude in the atmosphere over the past 60 years which can be used as boundary conditions for interpreting trapped air in glaciers and oceanic measurements of chlorocarbon tracers of the deep oceanic circulation. Some specific conclusions are as follows: (1) International compliance with the Montreal Protocol is so far resulting in chlorofluorocarbon and chlorocarbon mole fractions comparable to target levels; (2) mole fractions of total chlorine contained in long‐lived halocarbons (CCl2F2, CCl3F, CH3CCl3, CCl4, CHClF2, CCl2FCClF2, CH3Cl, CH2Cl2, CHCl3, CCl2=CCl2) in the lower troposphere reached maximum values of about 3.6 ppb in 1993 and are beginning to slowly decrease in the global lower atmosphere; (3) the chlorofluorocarbons have atmospheric lifetimes consistent with destruction in the stratosphere being their principal removal mechanism; (4) multiannual variations in chlorofluorocarbon and chlorocarbon emissions deduced from ALE/GAGE/AGAGE data are consistent approximately with variations estimated independently from industrial production and sales data where available (CCl2F2 (CFC‐12) and CCl2FCClF2 (CFC‐113) show the greatest discrepancies); (5) the mole fractions of the hydrochlorofluorocarbons and hydrofluorocarbons, which are replacing the regulated halocarbons, are rising very rapidly in the atmosphere, but with the exception of the much longer manufactured CHClF2 (HCFC‐22), they are not yet at levels sufficient to contribute significantly to atmospheric chlorine loading. These replacement species could in the future provide independent estimates of the global weighted‐average OH concentration provided their industrial emissions are accurately documented; (6) in the future, analysis of pollution events measured using high‐frequency in situ measurements of chlorofluorocarbons and their replacements may enable emission estimates at the regional level, which, together with industrial end‐use data, are of sufficient accuracy to be capable of identifying regional noncompliance with the Montreal Protocol.
Purpose
Benefit from convalescent plasma therapy for coronavirus disease 2019 (COVID-19) has been inconsistent in randomized clinical trials (RCTs) involving critically ill patients. As COVID-19 ...patients are immunologically heterogeneous, we hypothesized that immunologically similar COVID-19 subphenotypes may differ in their treatment responses to convalescent plasma and explain inconsistent findings between RCTs .
Methods
We tested this hypothesis in a substudy involving 1239 patients, by measuring 26 biomarkers (cytokines, chemokines, endothelial biomarkers) within the randomized, embedded, multifactorial, adaptive platform trial for community-acquired pneumonia (REMAP-CAP) that assigned 2097 critically ill COVID-19 patients to either high-titer convalescent plasma or usual care. Primary outcome was organ support free days at 21 days (OSFD-21) .
Results
Unsupervised analyses identified three subphenotypes/endotypes. In contrast to the more homogeneous subphenotype-2 (
N
= 128 patients, 10.3%; with elevated type i and type ii effector immune responses) and subphenotype-3 (
N
= 241, 19.5%; with exaggerated inflammation), the subphenotype-1 had variable biomarker patterns (
N
= 870 patients, 70.2%). Subphenotypes-2, and -3 had worse outcomes, and subphenotype-1 had better outcomes with convalescent plasma therapy compared with usual care (median (IQR). OSFD-21 in convalescent plasma vs usual care was 0 (− 1, 21) vs 10 (− 1, to 21) in subphenotype-2; 1.5 (− 1, 21) vs 12 (− 1, to 21) in suphenotype-3, and 0 (− 1, 21) vs 0 (− 1, to 21) in subphenotype-1 (test for between-subphenotype differences in treatment effects
p
= 0.008).
Conclusions
We reported three COVID-19 subphenotypes, among critically ill adults, with differential treatment effects to ABO-compatible convalescent plasma therapy. Differences in subphenotype prevalence between RCT populations probably explain inconsistent results with COVID-19 immunotherapies.
The accumulation of human-derived debris in the oceans is a global concern and a serious threat to marine wildlife. There is a volume of evidence that points to deleterious effects of marine debris ...(MD) on cetaceans in terms of both entanglement and ingestion. This review suggests that about 68% of cetacean species are affected by interacting with MD with an increase in the number of species reported to have interacted with it over the past decades. Despite the growing body of evidence, there is an ongoing debate on the actual effects of plastics on cetaceans and, in particular, with reference to the ingestion of microplastics and their potential toxicological and pathogenic effects. Current knowledge suggests that the observed differences in the rate and nature of interactions with plastics are the result of substantial differences in species-specific diving and feeding strategies. Existing projections on the production, use and disposal of plastics suggest a further increase of marine plastic pollution. In this context, the contribution of the ongoing COVID-19 pandemic to marine plastic pollution appears to be substantial, with potentially serious consequences for marine life including cetaceans. Additionally, the COVID-19 pandemic offers an opportunity to investigate the direct links between industry, human behaviours and the effects of MD on cetaceans. This could help inform management, prevention efforts, describe knowledge gaps and guide advancements in research efforts. This review highlights the lack of assessments of population-level effects related to MD and suggests that these could be rather immediate for small populations already under pressure from other anthropogenic activities. Finally, we suggest that MD is not only a pollution, economic and social issue, but also a welfare concern for the species and populations involved.
Display omitted
•The build-up of human-derived debris in the oceans is a global environmental plague.•68% of cetacean species are affected by marine debris either by ingestion or entanglement.•Covid-19 related debris are likely to further affect cetacean species.•Long-term population consequences of marine debris have not been assessed in 50 years.•Welfare concerns relating to marine debris are overlooked in conservation plans.
Dolphins are typically regarded as highly social animals. However, some individuals live apart from their own species and may come to socialize with people through a recognized series of stages which ...are presented and expanded on in this paper. The term "solitary-sociable dolphins" has been used to describe these animals and such individuals have been identified from several different species and reported in many parts of the world. In many instances, the interactions with people that may follow their original isolation, and which typically become more intense over time, have created situations where the welfare of the animal has been compromised by disturbance, injury, the feeding of inappropriate items and aggressive human behavior. Several solitary-sociable dolphins have also been deliberately injured and killed by humans. People who interact with these dolphins may also put themselves at risk of injury. This paper reports on recent cases drawing on published and unpublished sources. Since 2008, 32 solitary dolphins have been recorded including 27 bottlenose dolphins (25
and two
), two striped dolphins and three common dolphins. Four solitary belugas have also been recorded. There are some ten solitary dolphins and one beluga known at the present time. Laws and guidelines currently in place to protect solitary-sociable dolphins need to be strengthened and interactions with people should be avoided or, at the least, carefully managed to protect both the dolphin and the humans involved in the interaction. Terms, such as disturbance and harassment which are included in laws need to be clearly defined. Additionally, management plans for solitary-sociable dolphins need to be developed and adapted on a case by case basis taking into account the individual dolphin's sex, age, personality, stage of sociability and home range. It is also important that government officials and local stakeholders work together to implement guidelines which set out how the public can observe or interact with the dolphin safely.
Background ozone O
3 observations at Mace Head on the west coast of Ireland since 1987 show a significant positive trend of 0.49±0.19
ppb
year
−1 through to 2003. Increasing trends are observed for ...all seasons, with the largest trends during the winter season, 0.63±0.31
ppb
year
−1 and the smallest trends during the summer, 0.39±0.25
ppb
year
–1. However, this growth rate has not been consistent over time with a major anomaly evident in 1998–1999. This major O
3 perturbation is correlated with variations of CO
2, CO, CH
4, H
2 and CH
3Cl, which are likely due to large-scale biomass burning events in tropical and boreal regions during 1997–1999 coupled with an intense El Niño event. Over the 16 years of observations background O
3 has increased by about 8
ppb (∼24%) in the clean oceanic sectors representative of the Northern Hemisphere marine boundary layer.
The influence of topographic and temporal variables on cetacean distribution at a fine-scale is still poorly understood. To study the spatial and temporal distribution of harbour porpoise Phocoena ...phocoena and the poorly known Risso's dolphin Grampus griseus we carried out land-based observations from Bardsey Island (Wales, UK) in summer (2001-2007). Using Kernel analysis and Generalized Additive Models it was shown that porpoises and Risso's appeared to be linked to topographic and dynamic cyclic variables with both species using different core areas (dolphins to the West and porpoises to the East off Bardsey). Depth, slope and aspect and a low variation in current speed (for Risso's) were important in explaining the patchy distributions for both species. The prime temporal conditions in these shallow coastal systems were related to the tidal cycle (Low Water Slack and the flood phase), lunar cycle (a few days following the neap tidal phase), diel cycle (afternoons) and seasonal cycle (peaking in August) but differed between species on a temporary but predictable basis. The measure of tidal stratification was shown to be important. Coastal waters generally show a stronger stratification particularly during neap tides upon which the phytoplankton biomass at the surface rises reaching its maximum about 2-3 days after neap tide. It appeared that porpoises occurred in those areas where stratification is maximised and Risso's preferred more mixed waters. This fine-scale study provided a temporal insight into spatial distribution of two species that single studies conducted over broader scales (tens or hundreds of kilometers) do not achieve. Understanding which topographic and cyclic variables drive the patchy distribution of porpoises and Risso's in a Headland/Island system may form the initial basis for identifying potentially critical habitats for these species.
The effectiveness of surgery for colorectal cancer depends on it being carried out safely, which allows most patients to return to productive lives, with an improved postoperative life expectancy, or ...at least one that is not diminished by the surgery. Because colorectal cancer is a major cause of morbidity and mortality in elderly people, we have examined how the outcomes of surgery in elderly patients differ from those in younger patients.
We did a systematic review of published and aggregate data provided by investigators. Studies were identified by computerised and manual searches of published and unpublished reports, scanning references, and contacting investigators. Within each study, outcomes for patients aged 65–74 years, 75–84 years, and 85+ years were expressed in relation to those aged less than 65 years.
From 28 independent studies, and a total of 34194 patients, we found that elderly patients had an increased frequency of comorbid conditions, were more likely to present with later-stage disease and undergo emergency surgery, and less likely to have curative surgery than younger patients. The incidence of postoperative morbidity and mortality increased progressively with advancing age. Overall survival was reduced in elderly patients, but for cancer specific survival age-related differences were much less striking.
The relation between age and outcomes from colorectal cancer surgery is complex and may be confounded by differences in stage at presentation, tumour site, pre-existing comorbidities, and type of treatment received. However, selected elderly patients benefit from surgery since a large proportion survive for 2 or more years, irrespective of their age.
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