368 research outputs found
Island resort runoff threatens reef ecosystems: an isotopic assessment of the extent and impact of sewage-derived nitrogen across Redang Island, Terengganu, Peninsular Malaysia
Multiplicity dependence of identical particle correlations in the quantum optical approach
Identical particle correlations at fixed multiplicity are consideres in the
presence of chaotic and coherent fields. The multiplicity distribution,
one-particle momentum density, and two-particle correlation function are
obtained based on the diagrammatic representation for cmulants in
semi-inclusive events. Our formulation is applied to the analysis of the
experimental data on the multiplicity dependence of correlation functions
reported by the UA1 and the OPAL Collaborations.Comment: 14 pages, 7 figure
Analyses of multiplicity distributions with \eta_c and Bose-Einstein correlations at LHC by means of generalized Glauber-Lachs formula
Using the negative binomial distribution (NBD) and the generalized
Glauber-Lachs (GGL) formula, we analyze the data on charged multiplicity
distributions with pseudo-rapidity cutoffs \eta_c at 0.9, 2.36, and 7 TeV by
ALICE Collaboration and at 0.2, 0.54, and 0.9 TeV by UA5 Collaboration. We
confirm that the KNO scaling holds among the multiplicity distributions with
\eta_c = 0.5 at \sqrt{s} = 0.2\sim2.36 TeV and estimate the energy dependence
of a parameter 1/k in NBD and parameters 1/k and \gamma (the ratio of the
average value of the coherent hadrons to that of the chaotic hadrons) in the
GGL formula. Using empirical formulae for the parameters 1/k and \gamma in the
GGL formula, we predict the multiplicity distributions with \eta_c = 0.5 at 7
and 14 TeV. Data on the 2nd order Bose-Einstein correlations (BEC) at 0.9 TeV
by ALICE Collaboration and 0.9 and 2.36 TeV by CMS Collaboration are also
analyzed based on the GGL formula. Prediction for the 3rd order BEC at 0.9 and
2.36 TeV are presented. Moreover, the information entropy is discussed
Thermalized Displaced and Squeezed Number States in Coordinate Representation
Within the framework of thermofield dynamics, the wavefunctions of the
thermalized displaced number and squeezed number states are given in the
coordinate representation. Furthermore, the time evolution of these
wavefunctions is considered by introducing a thermal coordinate representation,
and we also calculate the corresponding probability densities, average values
and variances of position coordinate, which are consistent with results in the
literature.Comment: 12 pages, no figures, Revtex. v3: substantially revise
Decadal demographic shifts and size-dependent disturbance responses of corals in a subtropical warming hotspot
Funding supporting this research was provided by an Australian Research Council Discovery Early Career Research Award (DE230100141) and a University of Sydney Fellowship to BS, by the Australian Research Council Centre of Excellence for Coral Reef Studies (CE140100020) to JMP and others, the Australian Research Council Centre of Excellence for Environmental Decisions (CE110001014) and the Winifred Violet Scott Charitable Trust to MB, the Royal Geographical Society’s Ralph Brown Expedition Grant to MB and JC, the Natural Environment Research Council’s Sphere Doctoral Training Partnership to JC and the Natural Environment Research Council’s ONE Planet Doctoral Training Partnership (NE/S007512/1) and the European Commission’s Erasmus Traineeship to LL. This project has further received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant agreement TRIM-DLV-747102 to MB.Long-term demographic studies at biogeographic transition zones can elucidate how body size mediates disturbance responses. Focusing on subtropical reefs in eastern Australia, we examine trends in the size-structure of corals with contrasting life-histories and zoogeographies surrounding the 2016 coral bleaching event (2010–2019) to determine their resilience and recovery capacity. We document demographic shifts, with disproportionate declines in the number of small corals and long-term persistence of larger corals. The incidence of bleaching (Pocillopora, Turbinaria) and partial mortality (Acropora, Pocillopora) increased with coral size, and bleached corals had greater risk of partial mortality. While endemic Pocillopora experienced marked declines, decadal stability of Turbinaria despite bleaching, coupled with abundance increase and bleaching resistance in Acropora indicate remarkable resilience of these taxa in the subtropics. Declines in the number of small corals and variable associations with environmental drivers indicate bottlenecks to recovery mediated by inhibitory effects of thermal extremes for Pocillopora (heat stress) and Acropora (heat and cold stress), and stimulatory effects of chlorophyll-a for Turbinaria. Although our study reveals signs of resilience, it foreshadows the vulnerability of subtropical corals to changing disturbance regimes that include marine heatwaves. Disparity in population dynamics suggest that subtropical reefs are ecologically distinct from tropical coral reefs.Peer reviewe
Sewage-derived resort runoff threatens coral reefs? A pilot isotopic assessment of nitrogen at Pulau Redang, Malaysia
High-latitude marginal reefs support fewer but bigger corals than their tropical counterparts
Anthropogenic impacts are typically detrimental to tropical coral reefs, but the effect of increasing environmental stress and variability on the size structure of coral communities remains poorly understood. This limits our ability to effectively conserve coral reef ecosystems because size specific dynamics are rarely incorporated. Our aim is to quantify variation in the size structure of coral populations across 20 sites along a tropical-to-subtropical environmental gradient on the east coast of Australia (~ 23 to 30°S), to determine how size structure changes with a gradient of sea surface temperature, turbidity, productivity and light levels. We use two approaches: 1) linear regression with summary statistics (such as median size) as response variables, a method frequently favoured by ecologists and 2) compositional functional regression, a novel method using entire size–frequency distributions as response variables. We then predict coral population size structure with increasing environmental stress and variability. Together, we find fewer but larger coral colonies in marginal reefs, where conditions are typically more variable and stressful, than in tropical reefs. Our model predicts that coral populations may become gradually dominated by larger colonies (> 148 cm2) with increasing environmental stress. Fewer but bigger corals suggest low survival of smaller corals, slow growth, and/or poor recruitment. This finding is concerning for the future of coral reefs, as it implies that current marginal populations, or future reefs in increasingly stressful environmental conditions may have low recovery potential. We highlight the importance of continuously monitoring changes to population structure over biogeographic scales
Natural selection could determine whether <em>Acropora</em> corals persist under expected climate change
Prescribing Patterns of Fall Risk-Increasing Drugs in Older Adults Hospitalized for Heart Failure
BACKGROUND: Older adults hospitalized for heart failure (HF) are at risk for falls after discharge. One modifiable contributor to falls is fall risk-increasing drugs (FRIDs). However, the prevalence of FRIDs among older adults hospitalized for HF is unknown. We describe patterns of FRIDs use and examine predictors of a high FRID burden.
METHODS: We used the national biracial REasons for Geographic and Racial Differences in Stroke (REGARDS) study, a prospective cohort recruited from 2003-2007. We included REGARDS participants aged ≥ 65 years discharged alive after a HF hospitalization from 2003-2017. We determined FRIDs -cardiovascular (CV) and non-cardiovascular (non-CV) medications - at admission and discharge from chart abstraction of HF hospitalizations. We examined the predictors of a high FRID burden at discharge via modified Poisson regression with robust standard errors.
RESULTS: Among 1147 participants (46.5% women, mean age 77.6 years) hospitalized at 676 hospitals, 94% were taking at least 1 FRID at admission and 99% were prescribed at least 1 FRID at discharge. The prevalence of CV FRIDs was 92% at admission and 98% at discharge, and the prevalence of non-CV FRIDs was 32% at admission and discharge. The most common CV FRID at admission (88%) and discharge (93%) were antihypertensives; the most common agents were beta blockers (61% at admission, 75% at discharge), angiotensin-converting enzyme inhibitors (36% vs. 42%), and calcium channel blockers (32% vs. 28%). Loop diuretics had the greatest change in prevalence (53% vs. 72%). More than half of the cohort (54%) had a high FRID burden (Agency for Healthcare Research and Quality (AHRQ) score ≥ 6), indicating high falls risk after discharge. In a multivariable Poisson regression analysis, the factors strongly associated with a high FRID burden at discharge included hypertension (PR: 1.41, 95% CI: 1.20, 1.65), mood disorder (PR: 1.24, 95% CI: 1.10, 1.38), and hyperpolypharmacy (PR: 1.88, 95% CI: 1.64, 2.14).
CONCLUSIONS: FRID use was nearly universal among older adults hospitalized for HF; more than half had a high FRID burden at discharge. Further work is needed to guide the management of a common clinical conundrum whereby guideline indications for treating HF may contribute to an increased risk for falls
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