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1.
Nat Commun ; 14(1): 2313, 2023 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-37085476

RESUMO

The ability of reefs to protect coastlines from storm-driven flooding hinges on their capacity to keep pace with sea-level rise. Here, we show how and whether coral restoration could achieve the often-cited goal of reversing the impacts of coral-reef degradation to preserve this essential function. We combined coral-growth measurements and carbonate-budget assessments of reef-accretion potential at Buck Island Reef, U.S. Virgin Islands, with hydrodynamic modeling to quantify future coastal flooding under various coral-restoration, sea-level rise, and storm scenarios. Our results provide guidance on how restoration of Acropora palmata, if successful, could mitigate the most extreme impacts of coastal flooding by reversing projected trajectories of reef erosion and allowing reefs to keep pace with the ~0.5 m of sea-level rise expected by 2100 with moderate carbon-emissions reductions. This highlights the potential long-term benefits of pursuing coral-reef restoration alongside climate-change mitigation to support the persistence of essential coral-reef ecosystem services.


Assuntos
Antozoários , Recifes de Corais , Animais , Ecossistema , Elevação do Nível do Mar , Mudança Climática
3.
Am J Vet Res ; 82(2): 152-157, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33480279

RESUMO

OBJECTIVE: To evaluate surfactant protein D (SP-D) concentrations in serum and bronchoalveolar lavage fluid (BALF) from young healthy horses on pasture or housed in a typical barn. ANIMALS: 20 young healthy horses. PROCEDURES: Horses were randomly assigned to 1 of 2 groups (pasture, n = 10; barn, 10), and serum and BALF samples were collected for SP-D determination at baseline (all horses on pasture) and 2 weeks and 4 weeks after the barn group of horses was relocated from the pasture to the barn. Other evaluations included physical and tracheoscopic examinations. Findings were compared within and between groups. RESULTS: Physical and tracheoscopic examinations, CBC, and serum biochemical analysis did not reveal evidence of respiratory disease, and no significant differences were present within and between groups. Serum SP-D concentrations did not significantly differ within and between groups, but BALF SP-D concentrations were significantly lower for the barn group at 2 weeks but not at 4 weeks, compared with baseline. The BALF SP-D concentration-to-BALF total protein concentration ratio was < 1.5 and did not significantly differ within and between groups. CONCLUSIONS AND CLINICAL RELEVANCE: A mild decrease was evident in the concentration of SP-D in the BALF collected from young healthy horses after 2 weeks of exposure to a barn environment. The clinical importance of this finding remains to be determined.


Assuntos
Doenças dos Cavalos , Doenças Respiratórias , Animais , Lavagem Broncoalveolar/veterinária , Líquido da Lavagem Broncoalveolar , Cavalos , Proteína D Associada a Surfactante Pulmonar , Doenças Respiratórias/veterinária
4.
Ecology ; 101(12): e03180, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32882749

RESUMO

What happens in meadows after populations of natural grazers rebound following centuries of low abundance? Many seagrass ecosystems are now experiencing this phenomenon with the recovery of green turtles (Chelonia mydas), large-bodied marine herbivores that feed on seagrasses. These seagrass ecosystems provide a rare opportunity to study ecosystem-wide shifts that result from a recovery of herbivores. We evaluate changes in regulation of seagrass productivity in a naturally grazed tropical ecosystem by (1) comparing Thalassia testudinum productivity in grazed and ungrazed areas and (2) evaluating potential regulating mechanisms of T. testudinum productivity. We established 129 green turtle exclusion cages in grazed and ungrazed areas to quantify T. testudinum growth (linear, area, mass, productivity : biomass [P:B]). In each exclosure, we recorded temperature, irradiance, water depth, nitrogen : phosphorus ratio (N:P) of blade tissue, grazing intensity before cage placement, and T. testudinum structural and nutrient characteristics. Thalassia testudinum exhibited compensatory growth in grazed areas via stimulated blade linear growth, blade area growth, and P:B across seasonal high and low growth periods and in shallow (3-4 m) and deep (9-10 m) seagrass meadows. Irradiance, depth, and N:P ratios had significant roles in regulating mass growth and P:B of T. testudinum in ungrazed areas. Depth was a significant regulating factor of mass growth and P:B in grazed areas; rates were higher and more variable in shallow meadows than in deep meadows. Grazing intensity was also a significant regulating factor for P:B, stimulating tissue turnover with increasing grazing pressure. This study provides important insights into how recovery of a large marine herbivore can result in dramatic, sustainable changes in the regulation of seagrass productivity. We also highlight the need for a historical perspective and use of appropriate indicators, including P:B and grazing intensity, when evaluating seagrass response to green turtle grazing as meadows are returned to a natural grazed state. In an age of green turtle recovery and global seagrass decline due to anthropogenic threats, a thorough understanding of green turtle-seagrass interactions at the ecosystem level is critical to ensure the restoration of seagrass ecosystems and continued recovery of green turtle populations.


Assuntos
Ecossistema , Hydrocharitaceae , Animais , Biomassa , Região do Caribe , Herbivoria
5.
Artigo em Inglês | MEDLINE | ID: mdl-30036457

RESUMO

OBJECTIVE: To investigate blood pressure (BP) changes within the first 3 days after initiating antipsychotic medication in psychiatric inpatients. METHODS: Through retrospective chart review using a repeated measures design, vital signs data were collected on 60 adult psychiatric inpatients who were psychiatrically hospitalized May 26, 2011, through September 4, 2012, at 9 time points within 3 days of initiation of 1 of 6 different antipsychotic medications. The random sample included patients with the following DSM-IV-TR diagnoses: schizophrenia (n = 25), schizoaffective disorder (either type; n = 19), and bipolar I disorder (n = 16). Data were analyzed using mixed-effects repeated measures analysis of variance to evaluate associations between the antipsychotic initiated and subsequent changes in BP. The main outcome variable was change in BP from baseline, and independent variables included age, sex, psychiatric diagnosis, and type of antipsychotic medication. Logistic regression was used to assess the relationship between each type of antipsychotic and hypotension (BP < 90/60 mm Hg) and hypertension (BP ≥ 140/90 mm Hg). RESULTS: Olanzapine (P < .01) and risperidone (P = .01) raised systolic BP to a statistically significant degree during the first 3 days after initiation. Clozapine, on the other hand, significantly reduced systolic BP (P = .02) and was associated with hypotension on linear regression. No statistically significant associations were found between the other antipsychotics and acute systolic BP changes or between any of the 6 antipsychotics and diastolic BP changes. CONCLUSIONS: Initiation of certain antipsychotic medications may be associated with statistically significant acute BP changes. These findings require further evaluation in well-designed prospective studies.


Assuntos
Antipsicóticos/uso terapêutico , Transtorno Bipolar/tratamento farmacológico , Pressão Sanguínea/efeitos dos fármacos , Transtornos Psicóticos/tratamento farmacológico , Esquizofrenia/tratamento farmacológico , Adulto , Análise de Variância , Antipsicóticos/efeitos adversos , Transtorno Bipolar/fisiopatologia , Feminino , Hospitalização , Humanos , Hipertensão/induzido quimicamente , Hipotensão/induzido quimicamente , Modelos Lineares , Modelos Logísticos , Masculino , Transtornos Psicóticos/fisiopatologia , Estudos Retrospectivos , Esquizofrenia/fisiopatologia , Fatores de Tempo
6.
J Fish Biol ; 93(4): 649-663, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29971766

RESUMO

Analysing the associations between the endangered White's seahorse Hippocampus whitei and characteristics of its environment (including habitat, prey and predator variables) in an estuary in New South Wales, Australia, revealed that seahorses had a greater number of significant associations with environmental correlates within a single seagrass bed than among seagrass beds. Predator abundance was negatively correlated with H. whitei abundances among seven seagrass beds (200-6,000 m apart) and no ecological correlate was associated with H. whitei body size distributions. Within the seagrass bed with the greatest number of H. whitei, individuals preferentially selected locations that were deeper, had denser seagrass, more epiphytic prey types and fewer predators. Smaller H. whitei were associated with greater depths within the bed. In this study, each class of ecological correlate (habitat, prey, predators) was found to have at least one significant relationship with H. whitei, depending on the scale, demonstrating that all three are important to H. whitei populations. As such, future studies that evaluate animal populations may benefit from holistic approaches that consider each of these together. For animals that are experiencing dramatic population declines due to habitat destruction, as H. whitei has over the last decade, a better understanding of its relationship to its environment is important to inform conservation action.


Assuntos
Ecossistema , Smegmamorpha/fisiologia , Animais , Austrália , Tamanho Corporal , Estuários , New South Wales , Densidade Demográfica , Smegmamorpha/anatomia & histologia
7.
Ecol Appl ; 28(2): 336-347, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29350826

RESUMO

Population size is widely used as a unit of ecological analysis, yet to estimate population size requires accounting for observed and latent heterogeneity influencing dispersion of individuals across landscapes. In newly established populations, such as when animals are translocated for conservation, dispersal and availability of resources influence patterns of abundance. We developed a process to estimate population size using N-mixture models and spatial models for newly established and dispersing populations. We used our approach to estimate the population size of critically endangered St. Croix ground lizards (Ameiva polops) five years after translocation of 57 individuals to Buck Island, an offshore island of St. Croix, United States Virgin Islands. Estimates of population size incorporated abiotic variables, dispersal limits, and operative environmental temperature available to the lizards to account for low species detection. Operative environmental temperature and distance from the translocation site were always important in fitting the N-mixture model indicating effects of dispersal and species biology on estimates of population size. We found that the population is increasing its range across the island by 5-10% every six months. We spatially interpolated site-specific abundance from the N-mixture model to the entire island, and we estimated 1,473 (95% CI, 940-1,802) St. Croix ground lizards on Buck Island in 2013 corresponding to survey results. This represents a 26-fold increase since the translocation. We predicted the future dispersal of the lizards to all habitats on Buck Island, with the potential for the population to increase by another five times in the future. Incorporating biologically relevant covariates as explicit parameters in population models can improve predictions of population size and the future spread of species introduced to new localities.


Assuntos
Distribuição Animal , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Lagartos , Animais , Ecossistema , Feminino , Masculino , Densidade Demográfica , Ilhas Virgens Americanas
8.
Br J Anaesth ; 119(3): 384-393, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28969313

RESUMO

BACKGROUND: We assessed whether a near-infrared spectroscopy (NIRS)-based algorithm for the personalized optimization of cerebral oxygenation during cardiopulmonary bypass combined with a restrictive red cell transfusion threshold would reduce perioperative injury to the brain, heart, and kidneys. METHODS: In a randomized controlled trial, participants in three UK centres were randomized with concealed allocation to a NIRS (INVOS 5100; Medtronic Inc., Minneapolis, MN, USA)-based 'patient-specific' algorithm that included a restrictive red cell transfusion threshold (haematocrit 18%) or to a 'generic' non-NIRS-based algorithm (standard care). The NIRS algorithm aimed to maintain cerebral oxygenation at an absolute value of > 50% or at > 70% of baseline values. The primary outcome for the trial was cognitive function measured up to 3 months postsurgery. RESULTS: The analysis population comprised eligible randomized patients who underwent valve or combined valve surgery and coronary artery bypass grafts using cardiopulmonary bypass between December 2009 and January 2014 ( n =98 patient-specific algorithm; n =106 generic algorithm). There was no difference between the groups for the three core cognitive domains (attention, verbal memory, and motor coordination) or for the non-core domains psychomotor speed and visuo-spatial skills. The NIRS group had higher scores for verbal fluency; mean difference 3.73 (95% confidence interval 1.50, 5.96). Red cell transfusions, biomarkers of brain, kidney, and myocardial injury, adverse events, and health-care costs were similar between the groups. CONCLUSIONS: These results do not support the use of NIRS-based algorithms for the personalized optimization of cerebral oxygenation in adult cardiac surgery. CLINICAL TRIAL REGISTRATION: http://www.controlled-trials.com , ISRCTN 23557269.


Assuntos
Encéfalo/irrigação sanguínea , Encéfalo/fisiologia , Procedimentos Cirúrgicos Cardíacos , Circulação Cerebrovascular/fisiologia , Transtornos Cognitivos/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Ponte Cardiopulmonar , Transfusão de Eritrócitos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Reino Unido , Adulto Jovem
10.
Eur J Surg Oncol ; 41(8): 1005-12, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25986853

RESUMO

BACKGROUND: Prophylactic mastectomy (PM) has become increasingly common but is not without complications especially if accompanied by reconstructive surgery. In patients with sporadic unilateral breast cancer, contralateral PM offers no survival advantage. Multidisciplinary team (MDT) communication and interaction may facilitate shared decision-making and curtail PM rates. The aim of this study was investigate the effect of a regional MDT meeting on PM decision-making. METHODS: We conducted an observational study involving retrospective review of prospectively recorded MDT meeting records for a 151 patient requests for PM from 2011 to 2014. Final MDT decisions were recorded as PM 'accepted', 'declined' or 'pending'. For MDT sanctioned requests, the factors justifying PM were recorded. Where PM was declined, justification for MDT refusal was sought and recorded. RESULTS: Approximately half of all requests for PM have been upheld (53.0%) and 1/3 of requests have been declined (32.5%). Of those declined, low risk of contralateral breast cancer versus relatively high risk of systemic relapse were commonly cited as justification for PM refusal (45.7%). A proportion of patients who initiated PM discussion subsequently changed their minds (19.6%), or failed to attend clinic appointments (6.5%). Some patients were deemed medically unfit for complex reconstructive surgery (13%), or were declined on the basis of an apparent cosmetic drive for surgery (6.5%), concerns regarding depression or anxiety (2.2%) and/or if family history could not be substantiated (6.5%). DISCUSSION: MDT meetings facilitate cross-specialty interrogation of requests for PM, minimise unnecessary surgery and restrict PM to those likely to derive maximum benefit.


Assuntos
Neoplasias da Mama/prevenção & controle , Tomada de Decisões , Comunicação Interdisciplinar , Mastectomia/estatística & dados numéricos , Feminino , Humanos , Equipe de Assistência ao Paciente , Estudos Retrospectivos
12.
Environ Entomol ; 41(1): 72-80, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22525061

RESUMO

Diversity and abundance of ground beetles (Coleoptera: Carabidae) can be enhanced in vegetable and field intercropping systems, but the complexity of polycultures precludes the application of generalized assumptions of effects for novel intercropping combinations. In a field experiment conducted at Lacombe and Ellerslie, Alberta, Canada, in 2005 and 2006, we investigated the effects of intercropping canola (Brassica napus L.) with wheat (Triticum aestivum L.) on the diversity and community structure of carabid beetles, and on the activity density responses of individual carabid species. Shannon-Wiener diversity index scores and species evenness increased significantly as the proportion of wheat comprising total crop plant populations increased in one site-year of the study, indicating a positive response to enhanced crop plant species evenness in the intercrops, and in that same site-year, ground beetle communities in intercrops shifted to more closely approximate those in wheat monocultures as the percentage of wheat in the intercrops increased. Individual carabid species activity densities showed differing responses to intercropping, although activity densities of some potential root maggot (Delia spp.) (Diptera: Anthomyiidae) predators were greater in intercrops with high proportions of wheat than in canola monocultures. The activity density of Pterostichus melanarius (Illiger), the most abundant species collected, tended to be greater in canola monocultures than high-wheat intercrops or wheat monocultures. We conclude that intercrops of canola and wheat have the potential to enhance populations of some carabid species, therefore possibly exerting increased pressure on some canola insect pests.


Assuntos
Agentes de Controle Biológico , Biota , Besouros/fisiologia , Agricultura/métodos , Alberta , Animais , Brassica napus , Cadeia Alimentar , Densidade Demográfica , Estações do Ano , Triticum
13.
Clin Orthop Relat Res ; 470(3): 815-23, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21874389

RESUMO

BACKGROUND: As measured via static stability tests, the PCL is the dominant restraint to posterior tibial translation while the posterolateral corner is the dominant restraint to external tibial rotation. However, these uniplanar static tests may not predict multiplanar instability. The reverse pivot shift is a dynamic examination maneuver that may identify complex knee instability. QUESTIONS/PURPOSES: In this cadaver study, we asked whether (1) isolated sectioning or (2) combined sectioning of the PCL and posterolateral corner increased the magnitude of the reverse pivot shift and (3) the magnitude of the reverse pivot shift correlated with static external rotation or posterior drawer testing. METHODS: In Group I, we sectioned the PCL followed by structures of the posterolateral corner. In Group II, we sectioned the posterolateral corner structures before sectioning the PCL. We performed posterior drawer, external rotation tests, and mechanized reverse pivot shift for each specimen under each condition and measured translations via navigation. RESULTS: Isolated sectioning of the PCL or posterolateral corner had no effect on the reverse pivot shift. Conversely, combined sectioning of the PCL and posterolateral corner structures increased the magnitude of the reverse pivot shift. The magnitude of the reverse pivot shift correlated with the posterior drawer and external rotation tests. CONCLUSIONS: Combined sectioning of the PCL and posterolateral corner was required to cause an increase in the magnitude of the mechanized reverse pivot shift. The reverse pivot shift correlated with both static measures of stability. CLINICAL RELEVANCE: Combined injury to the PCL and posterolateral corner should be considered in the presence of a positive reverse pivot shift.


Assuntos
Instabilidade Articular/diagnóstico , Articulação do Joelho/fisiopatologia , Ligamento Cruzado Posterior/fisiopatologia , Adulto , Humanos , Instabilidade Articular/fisiopatologia , Pessoa de Meia-Idade , Exame Físico , Ligamento Cruzado Posterior/cirurgia , Rotação , Tíbia/fisiopatologia
14.
PLoS One ; 6(7): e21902, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21779351

RESUMO

BACKGROUND: Asthma exacerbations remain a major unmet clinical need. The difficulty in obtaining airway tissue and bronchoalveolar lavage samples during exacerbations has greatly hampered study of naturally occurring exacerbations. This study was conducted to determine if mRNA profiling of peripheral blood mononuclear cells (PBMCs) could provide information on the systemic molecular pathways involved during asthma exacerbations. METHODOLOGY/PRINCIPAL FINDINGS: Over the course of one year, gene expression levels during stable asthma, exacerbation, and two weeks after an exacerbation were compared using oligonucleotide arrays. For each of 118 subjects who experienced at least one asthma exacerbation, the gene expression patterns in a sample of peripheral blood mononuclear cells collected during an exacerbation episode were compared to patterns observed in multiple samples from the same subject collected during quiescent asthma. Analysis of covariance identified genes whose levels of expression changed during exacerbations and returned to quiescent levels by two weeks. Heterogeneity among visits in expression profiles was examined using K-means clustering. Three distinct exacerbation-associated gene expression signatures were identified. One signature indicated that, even among patients without symptoms of respiratory infection, genes of innate immunity were activated. Antigen-independent T cell activation mediated by IL15 was also indicated by this signature. A second signature revealed strong evidence of lymphocyte activation through antigen receptors and subsequent downstream events of adaptive immunity. The number of genes identified in the third signature was too few to draw conclusions on the mechanisms driving those exacerbations. CONCLUSIONS/SIGNIFICANCE: This study has shown that analysis of PBMCs reveals systemic changes accompanying asthma exacerbation and has laid the foundation for future comparative studies using PBMCs.


Assuntos
Asma/sangue , Asma/metabolismo , Transdução de Sinais/fisiologia , Adulto , Asma/genética , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Análise de Componente Principal , Transdução de Sinais/genética
15.
Science ; 333(6047): 1258-61, 2011 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-21737700

RESUMO

We report far-infrared and submillimeter observations of supernova 1987A, the star whose explosion was observed on 23 February 1987 in the Large Magellanic Cloud, a galaxy located 160,000 light years away. The observations reveal the presence of a population of cold dust grains radiating with a temperature of about 17 to 23 kelvin at a rate of about 220 times the luminosity of the Sun. The intensity and spectral energy distribution of the emission suggest a dust mass of about 0.4 to 0.7 times the mass of the Sun. The radiation must originate from the supernova ejecta and requires the efficient precipitation of all refractory material into dust. Our observations imply that supernovae can produce the large dust masses detected in young galaxies at very high redshifts.

16.
Rev Sci Instrum ; 82(3): 033707, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21456751

RESUMO

In this paper, a novel scanning probe microscope (SPM) modeling technique is presented. The novelty of this technique is that it exploits the SPM's probe-surface interaction measurement capabilities [e.g., the topography signal in atomic force microscopy (AFM)] to determine the SPM's lateral positioning dynamics. SPM operation speed is limited due to mechanical vibrations induced by movement of the SPM nanopositioner. In order to facilitate high-speed SPM operation, the dynamics of the SPM can be modeled and used to design feedforward and feedback controllers that reduce nanopositioner vibrations. The proposed technique seeks to develop a transfer function model of the SPM dynamics using only the SPM probe-surface interaction signal obtained while scanning a calibration sample. The technique is presented in the context of an AFM example, errors associated with the method are analyzed, and the method is experimentally verified using a commercial AFM. Experimental modeling results show that the method is capable of modeling the dynamics of SPM systems.

17.
J Econ Entomol ; 102(1): 219-28, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19253640

RESUMO

Reductions in oviposition and subsequent damage by root maggots (Diptera: Anthomyiidae, Delia spp.) to brassicaceous crops in the presence of nonhost plants has been demonstrated, but such investigations have not been conducted using intercrops of species commonly grown in the large-scale agricultural production systems of western Canada. A field experiment was conducted at three sites in Alberta, Canada, in 2005 and 2006 to determine interactions between root maggots and the various proportions of canola (Brassica napus L.) making up the total crop plant populations in intercrops with wheat (Triticum aestivum L.). The effect of a neonicotinoid seed treatment also was investigated. Root maggot damage to canola taproots decreased with increasing proportions of wheat in the intercrops. The presence of wheat in the intercrops had little effect on root maggot adult abundance in any single site-by-year combination or when data were combined over all sites and years, with different Delia species and sexes responding differently. Similarly, per plant root maggot egg populations were unaffected by intercropping, although egg populations were reduced on a per unit land area basis in intercrops compared with monocultures. Insecticidal seed treatment did not affect root maggot egg populations or canola root damage. Variable abundances and phenologies of the principal root maggot species infesting canola at different sites and years may influence their responses to canola-wheat intercrops. Intercropping canola and wheat may provide an opportunity for reducing crop damage from root maggot attack without compromising environmental sustainability.


Assuntos
Agricultura/métodos , Brassica napus/parasitologia , Dípteros/fisiologia , Controle de Insetos/métodos , Triticum , Animais , Brassica napus/crescimento & desenvolvimento , Comportamento Alimentar , Feminino , Interações Hospedeiro-Parasita , Larva , Masculino , Oviposição , Raízes de Plantas/parasitologia , Densidade Demográfica , Triticum/crescimento & desenvolvimento
18.
J Am Acad Orthop Surg ; 16(12): 679-88, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19056917

RESUMO

The Lachman and the pivot shift are the two clinical tests most commonly used to assess instability in the anterior cruciate ligament (ACL)-deficient knee. Because it is quantifiable, the Lachman test has become the benchmark for assessing the success of ACL reconstruction. As a result, surgical techniques have been developed that effectively eliminate anterior laxity of the knee. Recent studies have shown, however, that rotational stability is not always restored after ACL reconstruction. Furthermore, there is mounting evidence that the pivot shift examination correlates with functional instability and patient outcomes better than does any other physical examination test. This test attempts to reproduce the functional combined rotary and translational instability in the ACL-deficient knee. Although the pathologic kinematics of the pivot shift are difficult to measure, recent technological advances have allowed more accurate and objective descriptions of the pivot shift, which have furthered our understanding of the complex motions involved. These advances may lead to a method of quantifying the pivot shift for research purposes and, ultimately, to ACL reconstruction that is tailored specifically to each patient's objectively measured rotational instability.


Assuntos
Lesões do Ligamento Cruzado Anterior , Instabilidade Articular/diagnóstico , Traumatismos do Joelho/diagnóstico , Exame Físico/métodos , Ligamento Cruzado Anterior/fisiopatologia , Ligamento Cruzado Anterior/cirurgia , Humanos , Instabilidade Articular/fisiopatologia , Instabilidade Articular/cirurgia , Traumatismos do Joelho/fisiopatologia , Traumatismos do Joelho/cirurgia , Amplitude de Movimento Articular/fisiologia
19.
Knee Surg Sports Traumatol Arthrosc ; 16(5): 487-92, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18311485

RESUMO

ACL insufficiency can be documented clinically with the pivot shift maneuver, but the specific pathologic kinematics of the pivot shift is difficult to quantify. Navigation provides an opportunity to analyze in vivo the motions that comprise the pivot shift and the kinematic changes that are inherent after ACL reconstruction. We hypothesized that tibial rotation, anterior tibial translation (ATT), acceleration of posterior translation (APT) and the newly described angle of P, quantified during navigated pivot shift examination, correlate with clinical grading of the pivot shift phenomena. Navigation data from 12 patients who underwent navigated ACL surgery were retrospectively reviewed. A characteristic P-shaped track of motion is recorded by the navigation software during the pivot-shift examination. The "angle of P" was developed as a means characterizing this track of motion and was measured in all cases. The tibial rotation, maximum anterior tibial translation and acceleration of posterior translation during the pivot shift were also measured. The charts of these patients were reviewed to obtain information on the clinical grading of the pivot-shift before and after ACL reconstruction. Spearman correlation analysis was then used to identify significant correlations between clinical grade of the pivot shift and the angle of p measured with computer navigation. After reconstruction, the clinical grade of the pivot shift was zero in all patients. The tibial rotation, maximum ATT, APT and the angle of p also decreased. On analysis of 24 EUAs, 12 before reconstruction and 12 after, there was excellent and significant correlation between the clinical grade of pivot shift examination and the angle of P (R2 = 0.97, p < 0.001). Only good correlation was noted between the clinical pivot shift and the rotation (R2 = 0.77, p < 0.0001), maximum ATT (R2 = 0.87, p < 0.0001) and APT (R2 = 0.81, p < 0.0001). There was a stepwise increase of 6-7 mm of translation and 5-6 degrees of rotation for each increasing grade of pivot shift. There were also increases in the angle of P and APT for each increasing grade of pivot. A decrease in tibial rotation, maximum ATT, APT and angle ofp is detected by computer navigation with ACL reconstruction, correlating with clinical grading. Clinical quantification of the distinct elements of the pivot shift may allow for more accurate evaluation of different ACL reconstruction constructs. There is also potential for these variables to be measured intraoperatively and guide ACL reconstruction when computer navigation is employed.


Assuntos
Ligamento Cruzado Anterior/cirurgia , Instabilidade Articular/fisiopatologia , Articulação do Joelho/fisiopatologia , Cirurgia Assistida por Computador , Tíbia/fisiopatologia , Adolescente , Adulto , Lesões do Ligamento Cruzado Anterior , Enxerto Osso-Tendão Patelar-Osso , Feminino , Humanos , Masculino , Estudos Retrospectivos , Rotação
20.
Environ Entomol ; 37(6): 1451-60, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19161688

RESUMO

Aleochara bilineata Gyllenhal (Coleoptera: Staphylinidae) is an important natural enemy of root maggots (Delia spp.) (Diptera: Anthomyiidae), which are serious pests of brassicaceous crops in North America and Europe. Adults of A. bilineata feed on eggs and larvae of root maggots, and A. bilineata larvae parasitize Delia spp. pupae. Emergence and seasonal activity patterns of A. bilineata were investigated during 2003-2005 in canola (Brassica rapa L. and Brassica napus L.) in central Alberta, Canada, in relation to degree-day (DD) accumulations and Julian date. Captures of A. bilineata adults from pitfall traps within emergence cages situated over canola stubble from the previous year indicated that approximately 428, 493, and 455 DD (soil base 5.57 degrees C) and 187, 189, and 180 Julian days were required for 50% emergence in 2003, 2004, and 2005, respectively (3-yr mean = 185.1 +/- 2.8 Julian days [SEM]). Captures of A. bilineata adults from pitfall traps placed in current canola crops determined that 50% levels of activity density required 379 DD and 180 Julian days in 2004. A logistic model that described the relationship of degree-days and Julian days with emergence of adult beetles was appraised, and good correspondence was evident between predicted and observed cumulative emergence patterns. Emergence and seasonal activity periods of A. bilineata in canola were well synchronized with occurrence of preimaginal life stages of its principal hosts, Delia radicum (L.) and Delia platura Meigen, with beetle emergence beginning shortly after the onset of root maggot oviposition.


Assuntos
Brassica , Besouros/fisiologia , Controle Biológico de Vetores , Estações do Ano , Alberta , Animais , Brassica/crescimento & desenvolvimento , Feminino , Modelos Logísticos , Masculino , Densidade Demográfica
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