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1.
Environ Sci Technol ; 54(12): 7034-7036, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32510208
2.
J Antimicrob Chemother ; 74(2): 349-356, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30476137

RESUMO

Background: Increasing resistance drives empirical use of less potent and previously reserved antibiotics, including for urinary tract infections (UTIs). Molecular profiling, without culture, might better guide early therapy. Objectives: To explore the potential of AusDiagnostics multiplex tandem (MT) PCR UTI assays. Methods: Two MT-PCR assays were developed successively, seeking 8 or 16 resistance genes. Amplification was tracked in real time, with melting temperatures used to confirm product identity. Assays were variously performed on: (i) extracted DNA; (ii) cultured bacteria; (iii) urine spiked with reference strains; and (iv) bacteria harvested from clinical urines. Results were compared with those from sequencing, real-time SybrGreen PCR or phenotypic susceptibility. Results: Performance was similar irrespective of whether DNA, cultures or urines were used, with >90% sensitivity and specificity with respect to common ß-lactamases, dfr genes and aminoglycoside resistance determinants except aadA1/A2/A3, for which carriage correlated poorly with streptomycin resistance. Fluoroquinolone-susceptible and -resistant Escherichia coli (but not other species) were distinguished by the melting temperatures of their gyrA PCR products. The time from urine to results was <3 h. Conclusions: The MT-PCR assays rapidly identified resistance genes from Gram-negative bacteria in urines as well as from cultivated bacteria. Used directly on urines, this assay has the potential to guide early therapy.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Enterobacteriaceae/urina , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/genética , Reação em Cadeia da Polimerase Multiplex/métodos , DNA Bacteriano/genética , Infecções por Enterobacteriaceae/diagnóstico , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Fluoroquinolonas/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Sensibilidade e Especificidade , Infecções Urinárias/diagnóstico , Infecções Urinárias/microbiologia
3.
Br Dent J ; 225(3): 229-234, 2018 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-30095124

RESUMO

Objectives: The aim of this study was to investigate the reasons for placement and replacement of crowns in general dental practice. Methods: Forty general dental practitioners recorded the principal reason for the provision of new (initial) and replacement crowns for a maximum of up to 20 patients over a 20-week period. Results: A total of 664 patients received 783 crowns during the period of this study. Of these, 69% (n = 542) were new (initial) placements and 31% (n = 241) were replacements. Overall, tooth fracture (45%, n = 241) was the most frequently reported reason for new/ initial crown placements. Aesthetics (21%, n = 53) and secondary/recurrent caries (20%; n = 47) were the most frequent reasons for crown replacement. Maxillary premolars (27%, n = 145) and mandibular molars (25%, n = 137) were the teeth that received most initial crown placements. In contrast, maxillary incisors (50%, n = 115) were the most common teeth to receive a replacement crown. Dentists were more likely to replace a crown if they had not placed the original crown: 74% of replacement crowns (n = 178) were placed by a different dentist. Most patients had only one crown placed or replaced per course of treatment (n = 611; 90%). Conclusions: The results of this study reveal the prescribing habits of dentists in relation to provision of initial and replacement crowns. The vast majority of patients had only one crown provided per course of treatment, which is probably a reflection of funding schemes and changing patterns of oral health. This sample reported fewer replacement crowns than previous studies. In keeping with existing literature, crowns were more frequently replaced when the treating dentist had not placed the initial crown. However, against this, more replacements were provided for more long-standing patients (5+ years attendance) compared to those with shorter attendance history (<5 years). In an area where high quality evidence is lacking, further consensus on the need for placement and replacement crowns is needed. Such information would assist dentists to provide high-quality care and commissioners in developing an evidence-based service.


Assuntos
Coroas , Cárie Dentária/terapia , Padrões de Prática Odontológica , Fraturas dos Dentes/terapia , Estética Dentária , Humanos , Recidiva
4.
Biogeochemistry ; 135(1): 1-34, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-32009689

RESUMO

Continental shelf sediments are globally important for biogeochemical activity. Quantification of shelf-scale stocks and fluxes of carbon and nutrients requires the extrapolation of observations made at limited points in space and time. The procedure for selecting exemplar sites to form the basis of this up-scaling is discussed in relation to a UK-funded research programme investigating biogeochemistry in shelf seas. A three-step selection process is proposed in which (1) a target area representative of UK shelf sediment heterogeneity is selected, (2) the target area is assessed for spatial heterogeneity in sediment and habitat type, bed and water column structure and hydrodynamic forcing, and (3) study sites are selected within this target area encompassing the range of spatial heterogeneity required to address key scientific questions regarding shelf scale biogeochemistry, and minimise confounding variables. This led to the selection of four sites within the Celtic Sea that are significantly different in terms of their sediment, bed structure, and macrofaunal, meiofaunal and microbial community structures and diversity, but have minimal variations in water depth, tidal and wave magnitudes and directions, temperature and salinity. They form the basis of a research cruise programme of observation, sampling and experimentation encompassing the spring bloom cycle. Typical variation in key biogeochemical, sediment, biological and hydrodynamic parameters over a pre to post bloom period are presented, with a discussion of anthropogenic influences in the region. This methodology ensures the best likelihood of site-specific work being useful for up-scaling activities, increasing our understanding of benthic biogeochemistry at the UK-shelf scale.

5.
J Hosp Infect ; 94(4): 373-380, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27810221

RESUMO

BACKGROUND: All health workers should take responsibility for infection prevention and control (IPC). Recent reduction in key reported healthcare-associated infections in the UK is impressive, but the determinants of success are unknown. It is imperative to understand how IPC strategies operate as new challenges arise and threats of antimicrobial resistance increase. METHODS: The authors undertook a retrospective, independent evaluation of an action plan to enhance IPC and 'ownership' (individual accountability) for IPC introduced throughout a healthcare organization. Twenty purposively selected informants were interviewed. Data were analysed inductively. Normalization Process Theory (NPT) was applied to interpret the findings and explain how the action plan was operating. FINDINGS: Six themes emerged through inductive analysis. Theme 1: 'Ability to make sense of ownership' provided evidence of the first element of NPT (coherence). Regardless of occupational group or seniority, informants understood the importance of IPC ownership and described what it entailed. They identified three prerequisites: 'Always being vigilant' (Theme 2), 'Importance of access to information' (Theme 3) and 'Being able to learn together in a no-blame culture' (Theme 4). Data relating to each theme provided evidence of the other elements of NPT that are required to embed change: planning implementation (cognitive participation), undertaking the work necessary to achieve change (collective action), and reflection on what else is needed to promote change as part of continuous quality improvement (reflexive monitoring). Informants identified barriers (e.g. workload) and facilitators (clear lines of communication and expectations for IPC). CONCLUSION: Eighteen months after implementing the action plan incorporating IPC ownership, there was evidence of continuous service improvement and significant reduction in infection rates. Applying a theory that identifies factors that promote/inhibit routine incorporation ('normalization') of IPC into everyday health care can help explain the success of IPC initiatives and inform implementation.


Assuntos
Infecção Hospitalar/prevenção & controle , Controle de Infecções/métodos , Controle de Infecções/organização & administração , Responsabilidade Social , Infecção Hospitalar/epidemiologia , Feminino , Pesquisa sobre Serviços de Saúde , Humanos , Masculino , Estudos Retrospectivos , Reino Unido/epidemiologia
6.
J Hosp Infect ; 89(2): 77-81, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25549828

RESUMO

Little research has been undertaken on how infection prevention and control (IPC) teams operate and how their effectiveness is assessed. This review aimed to explore how IPC teams embed IPC throughout hospitals, balance outbreak management with strategic aspects of IPC work (e.g. education), and how IPC team performance is measured. A scoping exercise was performed combining literature searches, evidence synthesis, and intelligence from expert advisers. Eleven publications were identified. One paper quantified how IPC nurses spend their time, two described daily activities of IPC teams, five described initiatives to embed IPC across organizations following legislation since 1999 in the UK or changes in the delivery of healthcare, and three explored the contribution of IPC intermediaries (link nurses and champions). Eight publications reported research findings. The others reported how IPC teams are embedding IPC practice in UK hospitals. In conclusion, there is scope for research to explore different models of IPC team-working and effectiveness, and cost-effectiveness. Other topics that need addressing are the willingness and ability of ward staff to assume increased responsibility for IPC and the effectiveness of intermediaries.


Assuntos
Infecção Hospitalar/prevenção & controle , Controle de Infecções/métodos , Atitude do Pessoal de Saúde , Competência Clínica , Análise Custo-Benefício , Infecção Hospitalar/epidemiologia , Surtos de Doenças/prevenção & controle , Humanos , Controle de Infecções/normas , Enfermeiras e Enfermeiros , Guias de Prática Clínica como Assunto
7.
Sci Rep ; 4: 6463, 2014 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-25249055

RESUMO

The importance of individual species in mediating ecosystem process and functioning is generally accepted, but categorical descriptors that summarize species-specific contributions to ecosystems tend to reference a limited number of biological traits and underestimate the importance of how organisms interact with their environment. Here, we show how three functionally contrasting sediment-dwelling marine invertebrates affect fluid and particle transport - important processes in mediating nutrient cycling - and use high-resolution reconstructions of burrow geometry to determine the extent and nature of biogenic modification. We find that individual functional effect descriptors fall short of being able to adequately characterize how species mediate the stocks and flows of important ecosystem properties and that, in contrary to common practice and understanding, they are not substitutable with one another because they emphasize different aspects of species activity and behavior. When information derived from these metrics is combined with knowledge of how species behave and modify their environment, however, detailed mechanistic information emerges that increases the likelihood that a species functional standing will be appropriately summarized. Our study provides evidence that more comprehensive functional effect descriptors are required if they are to be of value to those tasked with projecting how altered biodiversity will influence future ecosystems.


Assuntos
Biodiversidade , Ecossistema , Extinção Biológica , Sedimentos Geológicos , Animais , Meio Ambiente , Poliquetos/química , Especificidade da Espécie
8.
Health Educ Res ; 29(5): 715-29, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24974218

RESUMO

The coalition literature recognizes context (geography, demographics and history) as a variable of interest, yet few coalition evaluation studies have focused on it. This study explores the association between geographic context and structures (e.g. member type) with functional characteristics (e.g. decision making or levels of conflict) in a statewide system of community health councils (coalitions). The study was part of a multiyear, statewide evaluation of New Mexico's health councils' contributions to systems-level changes. We adapted the Coalition Self-Assessment Survey (CSAS) for all county health council members and paid council coordinators. Both multilevel univariate and multivariate procedures were used to compare index scores, summaries of CSAS questions used to characterize council functions, with selected demographic variables and region. Member type was associated with decision making and policy capacity; paid staff expressed higher levels of agreement than voting members for both items. Length of membership was associated with decision making, positive leadership and shared vision. Results indicated that geographic context was significantly associated with many functional characteristics. The study highlights the idea that geographic context may influence coalition functioning. Understanding how geographic context influences coalition planning and actions may help explain differences among coalitions that on the surface share common organizational characteristics and external goals.


Assuntos
Participação da Comunidade , Comportamento Cooperativo , Coalizão em Cuidados de Saúde/organização & administração , Adolescente , Adulto , Idoso , Planejamento em Saúde Comunitária , Consenso , Tomada de Decisões Gerenciais , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Liderança , Masculino , Pessoa de Meia-Idade , Modelos Organizacionais , New Mexico , Saúde Pública/métodos , Adulto Jovem
9.
Diabet Med ; 31(11): 1431-8, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24798205

RESUMO

AIM: To develop and test a format of delivery of diabetes self-management education by paired professional and lay educators. METHODS: We conducted an equivalence trial with non-randomized participant allocation to a Diabetes Education and Self Management for Ongoing and Newly Diagnosed Type 2 diabetes (DESMOND) course, delivered in the standard format by two trained healthcare professional educators (to the control group) or by one trained lay educator and one professional educator (to the intervention group). A total of 260 people with Type 2 diabetes diagnosed within the previous 12 months were referred for self-management education as part of routine care and attended either a control or intervention format DESMOND course. The primary outcome measure was change in illness coherence score (derived from the Diabetes Illness Perception Questionnaire-Revised) between baseline and 4 months after attending education sessions. Secondary outcome measures included change in HbA1c level. The trial was conducted in four primary care organizations across England and Scotland. RESULTS: The 95% CI for the between-group difference in positive change in coherence scores was within the pre-set limits of equivalence (difference = 0.22, 95% CI 1.07 to 1.52). Equivalent changes related to secondary outcome measures were also observed, including equivalent reductions in HbA1c levels. CONCLUSION: Diabetes education delivered jointly by a trained lay person and a healthcare professional educator with the same educator role can provide equivalent patient benefits. This could provide a method that increases capacity, maintains quality and is cost-effective, while increasing access to self-management education.


Assuntos
Fortalecimento Institucional , Diabetes Mellitus Tipo 2/terapia , Hiperglicemia/prevenção & controle , Educação de Pacientes como Assunto , Assistência Centrada no Paciente , Autocuidado , Idoso , Estudos de Coortes , Diabetes Mellitus Tipo 2/sangue , Inglaterra , Feminino , Seguimentos , Hemoglobinas Glicadas/análise , Processos Grupais , Humanos , Masculino , Mentores , Pessoa de Meia-Idade , Cooperação do Paciente , Projetos Piloto , Escócia , Recursos Humanos
10.
Infect Drug Resist ; 5: 155-61, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23118545

RESUMO

BACKGROUND: The safety and protection of patients and health care workers is of paramount importance in dentistry, and this includes students in training who provide clinical care. Given the nature of dental care, adverse incidents can and do occur, exposing health care workers to body fluids and putting them at risk of infection, including contracting a blood-borne virus. The aim of this research was to analyze trends in the volume, rate, nature, management, and outcome of adverse incidents reported at one dental teaching hospital from 2005 to 2010. METHODS: Descriptive analysis of trends in the volume, rate, nature, management, and outcome of adverse incidents reported at one dental teaching hospital over a six-year period was undertaken in relation to the level of outpatient and day surgery activity. RESULTS: In total, 287 incidents were reported over a six-year period, which amounted to 0.039% of outpatient or day surgery appointments. Nearly three quarters of all the incidents (n = 208, 72%) took place during treatment or whilst clearing away after the appointment. The most frequent incidents were associated with administration of local anesthetic (n = 63, 22%), followed by burs used in dental hand pieces (n = 51, 18%). CONCLUSION: This research confirms that adverse incidents are a feature of dental hospitals and reports the common sources. The importance of accurate and consistent reporting of data to ensure that these issues are monitored to inform action and reduce risks to staff, students, and patients are highlighted.

11.
Environ Entomol ; 41(5): 1190-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23068177

RESUMO

The temperature-dependent development of tomato psyllid (also called potato psyllid), Bactericera cockerelli (Sulc), was studied in the laboratory at seven constant temperatures (8, 10, 15, 20, 23, 27, and 31°C), 50-60% RH, and a photoperiod of 16:8 (L:D) h on leaves of whole potato (Solanum tuberosum L.) and tomato (Solanum lycopersicum L.) plants. Developmental time in days for immature stages and total development (egg to adult) on both host species were inversely proportional to temperature between 8 and 27°C but increased at 31°C. One linear and two nonlinear models were fitted to the data. The lower developmental thresholds, calculated using the linear model for egg, total nymph, and total development (from oviposition to adult emergence) were 7.9, 4.2, and 7.1°C (reared on potato) and 7.2, 5.3, and 7.5°C (reared on tomato), respectively. The thermal constant (K) for total development was 358 (reared on potato), and 368 (reared on tomato) degree-days (DD). Two nonlinear models, Briere and Lactin, fit the data well as measured by goodness-of-fit criteria, the residual sum of square (RSS) and Akaike information criterion (AIC). Temperature threshold parameters for these nonlinear models (T(0), T(opt), and T(max)) were estimated for eggs, total nymphal stages, and total development time (egg to adult). The Briere model is highly recommended for the description of temperature-dependent development of tomato psyllid. Results from this study will provide basic information on the biology of tomato psyllid and have potential for the development of predictive models of the seasonal progress of this invasive pest.


Assuntos
Hemípteros/crescimento & desenvolvimento , Interações Hospedeiro-Parasita , Solanum lycopersicum/parasitologia , Solanum tuberosum/parasitologia , Temperatura , Animais , Feminino , Modelos Lineares , Masculino , Ninfa/crescimento & desenvolvimento , Óvulo/crescimento & desenvolvimento
12.
West Indian med. j ; 61(6): 580-586, Sept. 2012. graf, tab
Artigo em Inglês | LILACS | ID: lil-672961

RESUMO

OBJECTIVE: To evaluate the impact of a theory-based health education intervention on awareness of prostate cancer and intention to screen among men in Western Jamaica. METHODS: One hundred and eighty-eight men attending outpatient clinics in a hospital in Western Jamaica completed an interviewer-administered pretest survey. Following the pretest, participants received a health education intervention related to prostate cancer and an immediate post-test survey. RESULTS: There were statistically significant increases in the percentage of correct responses between the pretest and post-test (p < 0.05). The greatest improvement was among items measuring knowledge of prostate cancer screening tests. Participants moved across the Stages of Change theoretical constructs indicating intention to screen. CONCLUSION: The sample was receptive to information about prostate cancer and the use of a theory-based educational intervention positively influenced knowledge of prostate cancer risk factors, symptoms, and types of screenings. Practice implications: This theory-based patient education programme can be replicated to promote awareness of prostate cancer and informed screening methods including potential risk associated with screening behaviours.


OBJETIVO: Evaluar el impacto de una intervención de base teórica en educación para la salud sobre la conciencia acerca del cáncer de próstata y la disposición de los hombres en la región occidental de Jamaica, a someterse a pruebas de detección. MÉTODOS: Ciento ochenta y ocho hombres que asistían a las clínicas de consulta externa en un hospital en el occidente de Jamaica llenaron una encuesta de entrada administrada por el entrevistador. Tras la prueba de entrada, los participantes recibieron una intervención de educación para la salud en relación con el cáncer de la próstata e inmediatamente una encuesta de salida. RESULTADOS: Hubo aumentos estadísticamente significativos en el porcentaje de respuestas correctas entre la prueba de entrada y la prueba de salida (p < 0.05). La mayor mejora se observó en los ítems que medían el conocimiento acerca de las pruebas de detección del cáncer de próstata. Los participantes se movieron a través de los constructos teóricos de las etapas de cambio, indicando la intención de tamizaje. CONCLUSIÓN: La muestra fue receptiva a la información sobre el cáncer de próstata, y el uso de una intervención educativa de base teórica tuvo una influencia positiva sobre el conocimiento acerca de los factores de riesgo, síntomas y tipos de pruebas de detección del cáncer de próstata.


Assuntos
Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Neoplasias da Próstata/psicologia , Detecção Precoce de Câncer , Jamaica , Modelos Teóricos , Avaliação de Programas e Projetos de Saúde , Neoplasias da Próstata/diagnóstico
13.
West Indian Med J ; 61(6): 580-6, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23441351

RESUMO

OBJECTIVE: To evaluate the impact of a theory-based health education intervention on awareness of prostate cancer and intention to screen among men in Western Jamaica. METHODS: One hundred and eighty-eight men attending outpatient clinics in a hospital in Western Jamaica completed an interviewer-administered pretest survey. Following the pretest, participants received a health education intervention related to prostate cancer and an immediate post-test survey RESULTS: There were statistically significant increases in the percentage of correct responses between the pretest and post-test (p < 0.05). The greatest improvement was among items measuring knowledge of prostate cancer screening tests. Participants moved across the Stages of Change theoretical constructs indicating intention to screen. CONCLUSION: The sample was receptive to information about prostate cancer and the use of a theory-based educational intervention positively influenced knowledge of prostate cancer risk factors, symptoms, and types of screenings. PRACTICE IMPLICATIONS: This theory-based patient education programme can be replicated to promote awareness of prostate cancer and informed screening methods including potential risk associated with screening behaviours.


Assuntos
Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Neoplasias da Próstata/psicologia , Adulto , Idoso , Detecção Precoce de Câncer , Humanos , Jamaica , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Avaliação de Programas e Projetos de Saúde , Neoplasias da Próstata/diagnóstico
15.
Neurology ; 76(10): 914-22, 2011 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-21383328

RESUMO

BACKGROUND: Previous systematic reviews that examined whether atrial fibrillation (AF) is associated with dementia have relied on different study designs (including retrospective ones) and did not evaluate risk using meta-analysis. METHODS: We searched Medline, Embase, and PsychINFO in September 2010 for published prospective studies reporting on the association between baseline AF and incident dementia. Pooled odds ratios for AF and dementia were calculated using the random effects model, with heterogeneity assessed using I(2). RESULTS: We identified 15 relevant studies covering 46,637 participants, mean age 71.7 years. One study that reported no significant difference in Mini-Mental State Examination scores between patients with or without AF could not be pooled. Meta-analysis of the remaining 14 studies showed that AF was associated with a significant increase in dementia overall (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.4 to 2.7, p < 0.0001), with substantial heterogeneity (I(2) = 75%). When stratified by participants, the association was significant (with little heterogeneity) in studies focusing solely on patients with stroke (7 studies, OR 2.4, 95% CI 1.7 to 3.5, p < 0.001, I(2) = 10%), and of borderline significance (with substantial heterogeneity) for studies in broader populations (7 studies, OR 1.6, 95% CI 1.0 to 2.7, p = 0.05, I(2) = 87%). For conversion of mild cognitive impairment to dementia, one study showed a significant association with AF (OR 4.6, 95% CI 1.7 to 12.5). CONCLUSION: There is consistent evidence supporting an association between AF and increased incidence of dementia in patients with stroke whereas there remains considerable uncertainty about any link in the broader population. The potential association between AF and incident dementia in mild cognitive impairment merits further investigation.


Assuntos
Fibrilação Atrial/epidemiologia , Demência/epidemiologia , Bases de Dados Factuais/estatística & dados numéricos , Humanos , Incidência , Razão de Chances
16.
J R Army Med Corps ; 156(2): 121-4, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20648953

RESUMO

Severe facial wounds frequently result from improvised explosive devices (IEDs) as the face is still vulnerable despite advances in personal protection of soldiers. In contrast to the poor outcomes with civilian maxillofacial trauma management methods initially employed by the US Army for maxillofacial wounds from IEDs, advances in wound management methods for such injuries by the US Army have resulted in significant improvements in appearance and function. This article describes the features of a short course in the primary management of combat related maxillofacial wounds for deployed health care personnel who may not be facial specialists, including contemporary treatment techniques for those confronting wounds from IEDs which are explained in this course.


Assuntos
Traumatismos por Explosões/cirurgia , Educação Médica Continuada , Traumatismos Maxilofaciais/cirurgia , Militares/educação , Procedimentos Cirúrgicos Bucais/educação , Campanha Afegã de 2001- , Austrália , Traumatismos por Explosões/complicações , Humanos , Guerra do Iraque 2003-2011 , Traumatismos Maxilofaciais/etiologia , Cicatrização
17.
19.
Ecology ; 87(7): 1696-709, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16922320

RESUMO

Animals can be important in nutrient cycling in particular ecosystems, but few studies have examined how this importance varies along environmental gradients. In this study we quantified the nutrient cycling role of an abundant detritivorous fish species, the gizzard shad (Dorosoma cepedianum), in reservoir ecosystems along a gradient of ecosystem productivity. Gizzard shad feed mostly on sediment detritus and excrete sediment-derived nutrients into the water column, thereby mediating a cross-habitat translocation of nutrients to phytoplankton. We quantified nitrogen and phosphorus cycling (excretion) rates of gizzard shad, as well as nutrient demand by phytoplankton, in seven lakes over a four-year period (16 lake-years). The lakes span a gradient of watershed land use (the relative amounts of land used for agriculture vs. forest) and productivity. As the watersheds of these lakes became increasingly dominated by agricultural land, primary production rates, lake trophic state indicators (total phosphorus and chlorophyll concentrations), and nutrient flux through gizzard shad populations all increased. Nutrient cycling by gizzard shad supported a substantial proportion of primary production in these ecosystems, and this proportion increased as watershed agriculture (and ecosystem productivity) increased. In the four productive lakes with agricultural watersheds (>78% agricultural land), gizzard shad supported on average 51% of phytoplankton primary production (range 27-67%). In contrast, in the three relatively unproductive lakes in forested or mixed-land-use watersheds (>47% forest, <52% agricultural land), gizzard shad supported 18% of primary production (range 14-23%). Thus, along a gradient of forested to agricultural landscapes, both watershed nutrient inputs and nutrient translocation by gizzard shad increase, but our data indicate that the importance of nutrient translocation by gizzard shad increases more rapidly. Our results therefore support the hypothesis that watersheds and gizzard shad jointly regulate primary production in reservoir ecosystems.


Assuntos
Ecossistema , Peixes/fisiologia , Água Doce , Animais , Cadeia Alimentar , Fitoplâncton/fisiologia
20.
Int J Gynaecol Obstet ; 94(3): 382-5, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16839555

RESUMO

Professional liability insurance costs have increased rapidly in the last 10 years in the United States, while availability of companies offering professional liability insurance has decreased. The result is that ob-gyn physicians are changing their practice patterns. Many are no longer performing difficult or complex surgical procedures while others have stopped caring for obstetrical patients. Some physicians are retiring early or moving to other localities where there are less liability concerns. These changes all impact on the availability of health care for women. In addition, these problems have become a concern of medical students, and this is reducing the numbers considering a career in ob-gyn. Even where ob-gyns are available, hospitals and insurance carriers are limiting their ability to practice the wide range of procedures for which they were trained. Although legislative efforts to correct the problems are proposed, very few have been enacted. The end result is that women's health care has been threatened and will continue to face shortages and restrictions.


Assuntos
Seguro de Responsabilidade Civil/estatística & dados numéricos , Imperícia , Saúde da Mulher , Feminino , Ginecologia/legislação & jurisprudência , Acessibilidade aos Serviços de Saúde , Humanos , Responsabilidade Legal/economia , Imperícia/economia , Imperícia/legislação & jurisprudência , Imperícia/estatística & dados numéricos , Obstetrícia/legislação & jurisprudência , Estados Unidos
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