RESUMO
Community disassembly is the non-random process of progressive species declines and losses. This process is usually studied to determine how various forces extirpate species, such as catastrophic disturbance, species invasions, habitat fragmentation, or unnatural/anthropogenic stressors. However, in ephemeral ecosystems, community disassembly is a natural and repeatable process. While many ephemeral ecosystems are aquatic (vernal pools, playa lakes, rock pools, saline lakes, phytotelmata, etc.), some disassembly patterns are applicable to other ecosystem types, including terrestrial ecosystems. As ephemeral waterbodies near the end of their hydroperiod, certain aspects fundamentally change. These fundamental changes or mechanisms cause visible patterns of community disassembly. Decreasing habitat size eliminates microhabitats and increases encounter rates between organisms, possibly increasing predation and competition. A harshening habitat eliminates low-tolerance species, changes the proportions of specialists/generalists, and forces organisms to acclimate, emigrate, or die. Additionally, ultraviolet light affects more of the water column, eliminating unprotected species. Furthermore, the entire metacommunity is often in similar stages of disassembly and collapses. Many of these mechanisms drive disassembly of terrestrial ephemeral habitats, such as animal carcasses, dung pads, or fungal fruiting bodies. Organisms obligate to ephemeral habitats have evolved to optimize their life history for a rapid life cycle with specific adaptations for themselves or their offspring to survive through the inactive period of the ecosystem. While some disassembly may occur too fast for biotic interactions or compensatory dynamics to be important, organisms undergoing natural disassembly should "expect" it. Thus, predictions of disassembly based on internal or biotic patterns may be more common in natural disassembly scenarios than in human-induced disassembly of permanent ecosystems. Additionally, natural community disassembly should be more predictable and understandable than a permanent community's reaction to a never-before-seen anthropogenic disturbance. Community disassembly is an important ecological component of ephemeral ecosystems. The processes that occur during disassembly shape assemblages over ecologically and evolutionary relevant timescales. Understanding how natural disassembly can feed back to ultimately drive ecosystem structure and function increases our knowledge of fundamental ecology and provides for a new frontier of study.
Assuntos
Biodiversidade , Cadeia Alimentar , Áreas Alagadas , Animais , Fatores de TempoRESUMO
Approximately 5.7 million people in the United States experience heart failure, and about 670 000 new cases are diagnosed annually. Patients who are ineligible for heart transplant may benefit from a left ventricular assist device. These devices have provided patients with an increased life span, but eventually patients die of the underlying heart disease. This case study illustrates the appropriate use of palliative care teams to address preparedness planning and help decrease moral distress among nursing staff. (Critical Care Nurse. 2014; 34[2]:47-56).
Assuntos
Insuficiência Cardíaca/terapia , Cuidados Paliativos , Idoso , Ética Médica , Insuficiência Cardíaca/cirurgia , Coração Auxiliar , Humanos , MasculinoRESUMO
STUDY OBJECTIVE: Although 80-lead ECG body surface mapping is more sensitive for ST-elevation myocardial infarction (STEMI) than the 12-lead ECG, its clinical utility in chest pain in the emergency department (ED) has not been studied. We sought to determine the prevalence, clinical care patterns, and clinical outcomes of patients with STEMI identified on 80-lead but not on 12-lead (80-lead-only STEMI). METHODS: The Optimal Cardiovascular Diagnostic Evaluation Enabling Faster Treatment of Myocardial Infarction trial was a multicenter prospective observational study of moderate- to high-risk chest pain patients presenting to the ED. Patients received simultaneous 12-lead and 80-lead ECGs as part of their initial evaluation and were treated according to the standard of care, with clinicians blinded to the 80-lead results. The primary outcome of the trial was door-to-sheath time in patients with 80-lead-only STEMI versus patients with STEMI identified by 12-lead alone (12-lead STEMI). Secondary outcomes included angiographic and clinical outcomes at 30 days. RESULTS: One thousand eight hundred thirty patients were evaluated, 91 had a discharge diagnosis of 12-lead STEMI, and 25 patients met criteria for 80-lead-only STEMI. Eighty-four of the 91 12-lead STEMI patients underwent cardiac catheterization, with a median door-to-sheath time of 54 minutes, versus 14 of the 25 80-lead-only STEMI patients, with a door-to-sheath time of 1,002 minutes (estimated treatment difference in median=881; 95% confidence interval 181 to 1,079 minutes). Clinical outcomes and revascularization rates, however, were similar between 80-lead-only STEMI and 12-lead STEMI patients. CONCLUSION: The 80-lead ECG provides an incremental 27.5% increase in STEMI detection versus the 12-lead. Patients with 80-lead-only STEMI have adverse outcomes similar to those of 12-lead STEMI patients but are treated with delayed or conservative invasive strategies.
Assuntos
Mapeamento Potencial de Superfície Corporal , Infarto do Miocárdio/diagnóstico , Síndrome Coronariana Aguda/diagnóstico , Idoso , Erros de Diagnóstico/prevenção & controle , Método Duplo-Cego , Eletrocardiografia/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Análise de SobrevidaRESUMO
Investigations of outcomes of interprofessional education as a component of the basic preparation of health and human service professionals have lacked a strong focus on student perceptions, the student voice. This qualitative study examined students' insights regarding the interprofessional component of an elective course offered to 23 students; five from medicine and six from each of pharmaceutical sciences, nursing and social work. Fourteen students participated in focus group interviews at the conclusion of the course and 12 participated in telephone interviews six months later. The interviews explored perceptions regarding learning, including insights about the effectiveness of teaching-learning strategies, and improvements required. Experiential components of the course were more meaningful to students than theoretical components. Students perceived the use of practice-based learning, student interprofessional teams, and interprofessional collaboration in the classroom as particularly effective. The course contributed to students' development of their own professional voices and their understanding of those of other professions. Additional interpretive studies of students' experiences and those of faculty and professionals in practice are needed, particularly regarding strategies for increasing the effectiveness of experiential learning.