81 research outputs found
Disturbance Driven Colony Fragmentation as a Driver of a Coral Disease Outbreak
In September of 2010, Brewer’s Bay reef, located in St. Thomas (U.S. Virgin Islands), was simultaneously affected by
abnormally high temperatures and the passage of a hurricane that resulted in the mass bleaching and fragmentation of its
coral community. An outbreak of a rapid tissue loss disease among coral colonies was associated with these two
disturbances. Gross lesion signs and lesion progression rates indicated that the disease was most similar to the Caribbean
coral disease white plague type 1. Experiments indicated that the disease was transmissible through direct contact between
colonies, and five-meter radial transects showed a clustered spatial distribution of disease, with diseased colonies being
concentrated within the first meter of other diseased colonies. Disease prevalence and the extent to which colonies were
bleached were both significantly higher on unattached colony fragments than on attached colonies, and disease occurred
primarily on fragments found in direct contact with sediment. In contrast to other recent studies, disease presence was not
related to the extent of bleaching on colonies. The results of this study suggest that colony fragmentation and contact with
sediment played primary roles in the initial appearance of disease, but that the disease was capable of spreading among
colonies, which suggests secondary transmission is possible through some other, unidentified mechanism
Coral recruitment is impacted by the presence of a sponge community
© 2019 Peng Luo et al., published by De Gruyter, Berlin/Boston. C23H13NO4, monoclinic, P21/n (no. 14), a = 11.6537(6) Å, b = 5.1315(2) Å, c = 26.8047(13) Å, β = 96.266(3)°, V = 1593.4(13) Å3, Z = 4, Rgt(F) = 0.0531, wRref(F2) = 0.1432, T = 90.0(5) K
Dynamics of an Acute Coral Disease Outbreak Associated with the Macroalgae \u3cem\u3eDictyota\u3c/em\u3e SPP. in Dry Tortugas National Park, Florida, USA
Reports of coral disease outbreaks have increased in recent decades, but often few details are known about these outbreaks, such as environmental triggers, associated biological variables, or even the precise temporal span of the outbreak. Here we document an acute outbreak of a rapid tissue loss disease on the highest live coral cover (15%–30%) reefs within Dry Tortugas National Park, Florida, USA. This disease exhibited similar signs to white plague disease with the notable exception that a white film often was observed on the recently denuded skeleton. The temporal span of the disease was short (\u3c2 mo). Partial mortality was recorded but there was no detectable impact to overall coral cover. A significant increase and then decrease in the cover of macroalgae, primarily of the genus Dictyota, occurred simultaneously with the increase and drop in disease lesion density (number of lesions per living tissue area), respectively. No other anomalous biological or physical factors (e.g., unusual temperature, turbidity, passage of storms) corresponded with the outbreak, although it is likely that some environmental anomaly that was undetectable with the methods employed favored both disease and Dictyota expansion. This is the first study to associate a rapid increase in a macroalgal population with a coral disease outbreak. We highlight the need for increased study of the initiation of such outbreaks in the caribbean
Longitudinal Medication Usage in Alzheimer Disease Patients
This study examined in detail patterns of cholinesterase inhibitors (ChEIs) and memantine use and explored the relationship between patient characteristics and such use. Patients with probable Alzheimer disease AD (n=201) were recruited from the Predictors Study in 3 academic AD centers and followed from early disease stages for up to 6 years. Random effects logistic regressions were used to examine effects of patient characteristics on ChEIs/memantine use over time. Independent variables included measures of function, cognition, comorbidities, the presence of extrapyramidal signs, psychotic symptoms, age, sex, and patient's living situation at each interval. Control variables included assessment interval, year of study entry, and site. During a 6-year study period, rate of ChEIs use decreased (80.6% to 73.0%) whereas memantine use increased (2.0% to 45.9%). Random effects logistic regression analyses showed that ChEI use was associated with better function, no psychotic symptoms, and younger age. Memantine use was associated with better function, poorer cognition, living at home, later assessment interval, and later year of study entry. Results suggest that high rate of ChEI use and increasing memantine use over time are consistent with current practice guidelines of initiation of ChEIs in mild-to-moderate AD patients and initiation of memantine in moderate-to-severe patients
Utilization of Antihypertensives, Antidepressants, Antipsychotics, and Hormones in Alzheimer Disease
This study explores the longitudinal relationship between patient characteristics and use of 4 drug classes (antihypertensives, antidepressants, antipsychotics, and hormones) that showed significant changes in use rates over time in patients with Alzheimer disease. Patient/caregiver-reported prescription medication usage was categorized by drug class for 201 patients from the Predictors Study. Patient characteristics included use of cholinesterase inhibitors and/or memantine, function, cognition, living situation, baseline age, and sex. Assessment interval, year of study entry, and site were controlled for. Before adjusting for covariates, useage increased for antihypertensives (47.8% to 62.2%), antipsychotics (3.5% to 27.0%), and antidepressants (32.3% to 40.5%); use of hormones decreased (19.4% to 5.4%). After controlling for patient characteristics, effects of time on the use of antidepressants were no longer significant. Antihypertensive use was associated with poorer functioning, concurrent use of memantine, and older age. Antipsychotic use was associated with poorer functioning and poorer cognition. Antidepressant use was associated with younger age, poorer functioning, and concurrent use of cholinesterase inhibitors and memantine. Hormone use was associated with being female and younger age. Findings suggest accurate modeling of the Alzheimer disease treatment paradigm for certain subgroups of patients should include antihypertensives and antipsychotics in addition to cholinesterase inhibitors and memantine
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An Investigation of Clinical Correlates of Lewy Bodies in Autopsy-Proven Alzheimer Disease
Background: Studies of patients meeting clinical and pathologic criteria for Alzheimer disease (AD) have not consistently found associations between the presence of Lewy bodies (LBs) at postmortem examination and a higher frequency during life of the clinical features of dementia with LBs. Objective: To evaluate the clinical correlates of LBs in patients with AD. Design and Methods: Fifty-one patients were diagnosed as having probable AD during life and met pathologic criteria for AD. Semiquantitative ratings for LBs were obtained in 4 brain regions: substantia nigra, cingulate, insular cortex, and hippocampus. The patients had been followed up semiannually for up to 9.9 years before death, and clinical features associated with dementia with LBs, including extrapyramidal signs and visual hallucinations, were assessed at each study visit. Logistic regression analyses determined whether patients who had LBs were more likely than those without LBs to express specific clinical signs during follow-up. Cox analyses determined whether patients with LBs developed clinical signs or died earlier. Generalized estimating equations were used to compare rates of cognitive or functional change. Results: Nineteen of the 51 patients had at least 1 LB in one of the studied regions. In no case was a significant relation noted between LBs and the presence of a measured clinical sign. No LB measure was associated with an increased risk of developing any of the evaluated clinical signs earlier in the disease. There was no association between the presence of LBs and more rapid mortality or more rapid disease progression. Conclusions: In patients diagnosed as having AD during life, we did not observe a relation of LBs noted during postmortem examination with the presence of any clinical feature that we assessed or with the rapidity of disease progression. The relation between LBs and specific clinical manifestations may be tenuous in these patients
Long-Term Associations between Cholinesterase Inhibitors and Memantine Use and Health Outcomes among Patients with Alzheimer's Disease
OBJECTIVES: To examine in an observational study (1) relationships between cholinesterase inhibitors (ChEI) and memantine use, and functional and cognitive end points and mortality in patients with Alzheimer's disease (AD); (2) relationships between other patient characteristics and these clinical end points; and (3) whether effects of the predictors change across time. METHODS: The authors conducted a multicenter, natural history study that included three university-based AD centers in the United States. A total of 201 patients diagnosed with probable AD with modified Mini-Mental State Examination (MMSE) scores >/= 30 at study entry were monitored annually for 6 years. Discrete-time hazard analyses were used to examine relationships between ChEI and memantine use during the previous 6 months reported at each assessment, and time to cognitive (MMSE score /= 10) end points and mortality. Analyses controlled for clinical characteristics, including baseline cognition, function, and comorbid conditions, and presence of extrapyramidal signs and psychiatric symptoms at each assessment interval. Demographic characteristics included baseline age, sex, education, and living arrangement at each assessment interval. RESULTS: ChEI use was associated with delayed time in reaching the functional end point and death. Memantine use was associated with delayed time to death. Different patient characteristics were associated with different clinical end points. CONCLUSIONS: Results suggest long-term beneficial effects of ChEI and memantine use on patient outcomes. As for all observational cohort studies, observed relationships should not be interpreted as causal effects
Stony coral tissue loss disease: a review of emergence, impacts, etiology, diagnostics, and intervention
Stony coral tissue loss disease (SCTLD) is destructive and poses a significant threat to Caribbean coral reef ecosystems. Characterized by the acute loss of coral tissue, SCTLD has impacted over 22 stony coral species across the Caribbean region, leading to visible declines in reef health. Based on the duration, lethality, host range, and spread of this disease, SCTLD is considered the most devastating coral disease outbreak ever recorded. Researchers are actively investigating the cause and transmission of SCTLD, but the exact mechanisms, triggers, and etiological agent(s) remain elusive. If left unchecked, SCTLD could have profound implications for the health and resilience of coral reefs worldwide. To summarize what is known about this disease and identify potential knowledge gaps, this review provides a holistic overview of SCTLD research, including species susceptibility, disease transmission, ecological impacts, etiology, diagnostic tools, host defense mechanisms, and treatments. Additionally, future research avenues are highlighted, which are also relevant for other coral diseases. As SCTLD continues to spread, collaborative efforts are necessary to develop effective strategies for mitigating its impacts on critical coral reef ecosystems. These collaborative efforts need to include researchers from diverse backgrounds and underrepresented groups to provide additional perspectives for a disease that requires creative and urgent solutions
Smoking, self-regulation and moral positioning: a focus group study with British smokers from a disadvantaged community
Smoking in many Western societies has become a both moral aand health issue in recent years, but little is known about how smokers position themselves and regulate their behaviour in this context. In this article, we report the findings from a study investigating how smokers from an economically disadvantaged community in the East Midlands (UK) respond to concerns about the health impact of smoking on others. We conducted ten focus group (FG) discussions with mixed groups (by smoking status and gender; N = 58 participants) covering a range of topics, including smoking norms, self-regulation, and smoking in diverse contexts. We transcribed all FG discussions before analysing the data using techniques from discourse anlysis. Smokers in general positioned themselves as socially responsible smokers and morally upstanding citizens. This position was bolstered in two main ways: ‘everyday accommodation', whereby everyday efforts to accommodate the needs of non-smokers were referenced, and ‘taking a stand', whereby proactive interventions to prevent smoking in (young) others were cited. We suggest that smoking cessation campaigns could usefully be informed by this ethic of care for others
U.S. Billion-ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry
The Report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of “potential” biomass within the contiguous United States based on numerous assumptions about current and future inventory and production capacity, availability, and technology. In the 2005 BTS, a strategic analysis was undertaken to determine if U.S. agriculture and forest resources have the capability to potentially produce at least one billion dry tons of biomass annually, in a sustainable manner—enough to displace approximately 30% of the country’s present petroleum consumption. To ensure reasonable confidence in the study results, an effort was made to use relatively conservative assumptions. However, for both agriculture and forestry, the resource potential was not restricted by price. That is, all identified biomass was potentially available, even though some potential feedstock would more than likely be too expensive to actually be economically available.
In addition to updating the 2005 study, this report attempts to address a number of its shortcoming
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