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1.
Phys Rev Lett ; 132(6): 065104, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38394572

RESUMO

As fusion experiments at the National Ignition Facility (NIF) approach and exceed breakeven, energy from the burning capsule is predicted to couple to the gold walls and reheat the hohlraum. On December 5, 2022, experiment N221204 exceeded target breakeven, historically achieving 3.15 MJ of fusion energy from 2.05 MJ of laser drive; for the first time, energy from the igniting capsule reheated the hohlraum beyond the peak laser-driven radiation temperature of 313 eV to a peak of 350 eV, in less than half a nanosecond. This reheating effect has now been unambiguously observed by the two independent Dante calorimeter systems across multiple experiments, and is shown to result from reheating of the remnant tungsten-doped ablator by the exploding core, which is heated by alpha deposition.

2.
HERD ; 17(1): 148-163, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37340757

RESUMO

OBJECTIVE: Translational research to advance design criteria and apply the Childbirth Supporter Study (CSS) findings to practice. BACKGROUND: The physical design of birth environments has not undergone substantial improvements in layout or ambiance since the initial move to hospitals. Cooperative, continuously present childbirth supporters are beneficial and are an expectation for most modern birth practices, yet the built environment does not offer support for the supporter. METHODS: To advance design criteria, we use a comparative case study approach to create translational findings. Specifically, CSS findings were used as indicators to advance the Birth Unit Design Spatial Evaluation Tool (BUDSET) design characteristics in pursuit of better support for childbirth supporters in the built hospital birth environment. RESULTS: This comparative case study provides eight new BUDSET design domain suggestions to benefit the supporter-woman dyad, and subsequently the baby and care providers. CONCLUSIONS: Research-informed design imperatives are needed to guide the inclusion of childbirth supporters as both a supporter and as an individual in the birth space. Increased understanding of relationships between specific design features and childbirth supporters' experiences and reactions are provided. Suggestions to enhance the applicability of the BUDSET for birth unit design facility development are made, specifically ones that will better accommodate childbirth supporters.


Assuntos
Centros de Assistência à Gravidez e ao Parto , Arquitetura Hospitalar , Gravidez , Feminino , Humanos , Recém-Nascido , Parto Obstétrico , Projetos de Pesquisa , Instalações de Saúde , Parto
3.
J Neurosci Methods ; 363: 109352, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34508784

RESUMO

BACKGROUND: Statistical detection methods are routinely used to automate auditory evoked response (AER) detection and assist clinicians with AER measurements. However, many of these methods are built around statistical assumptions that can be violated for AER data, potentially resulting in reduced or unpredictable test performances. This study explores a frequency domain bootstrap (FDB) and some FDB modifications to preserve test performance in serially correlated non-stationary data. METHOD: The FDB aims to generate many surrogate recordings, all with similar serial correlation as the original recording being analysed. Analysing the surrogates with the detection method then gives a distribution of values that can be used for inference. A potential limitation of the conventional FDB is the assumption of stationary data with a smooth power spectral density (PSD) function, which is addressed through two modifications. COMPARISONS WITH EXISTING METHODS: The FDB was compared to a conventional parametric approach and two modified FDB approaches that aim to account for heteroskedasticity and non-smooth PSD functions. Hotelling's T2(HT2) test applied to auditory brainstem responses was the test case. RESULTS: When using conventional HT2, false-positive rates deviated significantly from the nominal alpha-levels due to serial correlation. The false-positive rates of the modified FDB were consistently closer to the nominal alpha-levels, especially when data was strongly heteroskedastic or the underlying PSD function was not smooth due to e.g. power lines noise. CONCLUSION: The FDB and its modifications provide accurate, recording-dependent approximations of null distributions, and an improved control of false-positive rates relative to parametric inference for auditory brainstem response detection.


Assuntos
Potenciais Evocados Auditivos do Tronco Encefálico , Potenciais Evocados Auditivos , Ruído
4.
J Psychiatr Res ; 143: 183-188, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34500347

RESUMO

BACKGROUND: Results of research regarding a possible causal relation between autism spectrum disorders (ASDs) and violence are mixed. Several explanations have been proposed. AIMS: To assess prevalence rates of comorbid disorders in a large sample of mentally ill offenders diagnosed with ASD. Offenders with and without comorbid mental disorders were compared on several characteristics. To better understand the relationship between ASD and violent criminal behavior, the predictive value of several proposed risk factors (comorbidity, negative social network/influenceability, and childhood trauma/victimization) on violent offending was investigated. METHOD: Data of 394 male offenders with a diagnosis of ASD were included. Prevalence rates of comorbid mental disorders next to ASD were calculated, and characteristics were compared using chi-square or t-tests. The predictive value of the risk factors was assessed using a binary logistic regression (n = 357). RESULTS: High rates of comorbidity were found (78.9%), specifically for substance use disorders (39.8%), schizophrenia spectrum disorders (31.7%), and neurodevelopmental disorder other than ASD (24.1%). Offenders with and without comorbidity differed significantly in their criminal and mental health care history. Both comorbidity (OR = 1.68; 95% CI 1.27-2.18) and a negative social network/influenceability (OR = 1.49; 95% CI 1.11-1.99) showed to be significant predictors of violent offending within this sample. CONCLUSIONS: The highest rates of comorbid disorders found were disorders that have been previously linked to violent offending, and the risk of violent offending could be unrelated to ASD. However, the role of social functioning indicates a risk specific to the symptoms of ASD.


Assuntos
Transtorno do Espectro Autista , Transtornos Mentais , Pessoas Mentalmente Doentes , Prisioneiros , Transtornos Relacionados ao Uso de Substâncias , Transtorno do Espectro Autista/epidemiologia , Humanos , Masculino , Transtornos Mentais/epidemiologia , Fatores de Risco , Violência
5.
Int J Audiol ; 58(10): 618-627, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31259611

RESUMO

Objective: To detect the auditory brainstem response (ABR) automatically using an innovative sequentially applied Hotelling's T 2 test, with the overall goal of optimising test time whilst controlling the false-positive rate (FPR). Design: The stage-wise critical decision boundaries for accepting or rejecting the null hypothesis were found using a new approach called the Convolutional Group Sequential Test (CGST). Specificity, sensitivity, and test time were evaluated using simulations and subject recorded data. Study sample: Data consists of click-evoked ABR threshold series from 12 normal hearing adults, and recordings of EEG background activity from 17 normal hearing adults. Results: Reductions in mean test time of up to 40-45% were observed for the sequential test, relative to a conventional "single shot" test where the statistical test is applied to the data just once. To obtain these results, it will occasionally be necessary to run the test to a higher number of stimuli, i.e. the maximum test time needs to be increased. Conclusions: The CGST can be used to control the specificity of a sequentially applied ABR detection method. Doing so can reduce test time, relative to the "single shot" test, when considered across a cohort of test subjects.


Assuntos
Técnicas de Diagnóstico Neurológico , Potenciais Evocados Auditivos do Tronco Encefálico , Humanos , Sensibilidade e Especificidade , Estatística como Assunto
6.
Int J Audiol ; 57(6): 468-478, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29537327

RESUMO

OBJECTIVE: To evaluate and compare the specificity, sensitivity and detection time of various time-domain and multi-band frequency domain methods when detecting the auditory brainstem response (ABR). DESIGN: Simulations and subject recorded data were used to assess and compare the performance of the Hotelling's T2 test (applied in either time or frequency domain), two versions of the modified q-sample uniform scores test and both the Fsp and Fmp, which were evaluated using both conventional F-distributions with assumed degrees of freedom and a bootstrap approach. STUDY SAMPLE: Data consisted of click-evoked ABRs and recordings of EEG background activity from 12 to 17 normal hearing adults, respectively. RESULTS: An overall advantage in sensitivity and detection time was demonstrated for the Hotelling's T2 test. The false-positive rates (FPRs) of the Fsp and Fmp were also closer to the nominal alpha-level when evaluating statistical significance using the bootstrap approach, as opposed to using conventional F-distributions. The FPRs of the remaining methods were slightly higher than expected. CONCLUSIONS: In this work, Hotelling's T2 outperformed the alternative methods for automatically detecting ABRs. Its promise as a sensitive and efficient detection method should now be tested in a larger clinical study.


Assuntos
Estimulação Acústica/métodos , Limiar Auditivo/fisiologia , Eletroencefalografia/estatística & dados numéricos , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Tempo de Reação , Adulto , Reações Falso-Positivas , Feminino , Humanos , Masculino , Sensibilidade e Especificidade , Fatores de Tempo
7.
Int J Offender Ther Comp Criminol ; 62(13): 4158-4173, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29426253

RESUMO

There is evidence that psychiatric patients with psychotic or manic disorders who are incarcerated suffer from the same symptoms as psychiatric patients who are treated in the community. There are also indications that their symptoms might be more severe. The aim of this study was to examine the severity of psychotic and manic symptoms, as well as to collect information about the emotional functioning of patients admitted to a prison psychiatric ward. Incarcerated patients with a diagnosis of psychotic or a manic disorder were examined with the Brief Psychiatric Rating Scale-Expanded (BPRS-E). With the scores of 140 assessments, a symptom profile was created using the domains of the BPRS-E. This profile was compared with the clinical profile of three nonincarcerated patient groups described in literature with a diagnosis in the same spectrum. We found high scores on positive and manic psychotic symptoms and hostility, and low scores on guilt, depression, and negative symptoms. High scores on manic and psychotic symptoms are often accompanied by violent behavior. Low scores on guilt, depression, and negative symptoms could be indicative of externalizing coping skills. These characteristics could complicate treatment in the community and warrant further research along with clinical consideration.


Assuntos
Transtornos Psicóticos Afetivos/diagnóstico , Prisioneiros/psicologia , Transtornos Psicóticos/diagnóstico , Índice de Gravidade de Doença , Adulto , Transtornos Psicóticos Afetivos/psicologia , Transtorno Bipolar/diagnóstico , Escalas de Graduação Psiquiátrica Breve , Depressão/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prisões , Transtornos Psicóticos/psicologia , Adulto Jovem
8.
Psychol Med ; 47(10): 1784-1793, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28173890

RESUMO

BACKGROUND: A growing body of neuropsychological and neurobiological research shows a relationship between functioning of the prefrontal cortex and criminal and violent behaviour. The prefrontal cortex is crucial for executive functions such as inhibition, attention, working memory, set-shifting and planning. A deficit in these functions - a prefrontal deficit - may result in antisocial, impulsive or even aggressive behaviour. While several meta-analyses show large effect sizes for the relationship between a prefrontal deficit, executive dysfunction and criminality, there are few studies investigating differences in executive functions between violent and non-violent offenders. Considering the relevance of identifying risk factors for violent offending, the current study explores whether a distinction between violent and non-violent offenders can be made using an extensive neuropsychological test battery. METHOD: Male remand prisoners (N = 130) in Penitentiary Institution Amsterdam Over-Amstel were administered an extensive neuropsychological test battery (Cambridge Automated Neuropsychological Test Battery; CANTAB) measuring response inhibition, planning, attention, set-shifting, working memory and impulsivity/reward sensitivity. RESULTS: Violent offenders performed significantly worse on the stop-signal task (partial correlation r = 0.205, p = 0.024), a task measuring response inhibition. No further differences were found between violent and non-violent offenders. Explorative analyses revealed a significant relationship between recidivism and planning (partial correlation r = -0.209, p = 0.016). CONCLUSION: Violent offenders show worse response inhibition compared to non-violent offenders, suggesting a more pronounced prefrontal deficit in violent offenders than in non-violent offenders.


Assuntos
Criminosos , Função Executiva/fisiologia , Inibição Psicológica , Córtex Pré-Frontal/fisiopatologia , Violência , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Prisioneiros , Adulto Jovem
9.
Nurs Ethics ; 24(2): 177-189, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26208721

RESUMO

BACKGROUND: Conducting video-research in birth settings raises challenges for ethics review boards to view birthing women and research-midwives as capable, autonomous decision-makers. AIM: This study aimed to gain an understanding of how the ethical approval process was experienced and to chronicle the perceived risks and benefits. RESEARCH DESIGN: The Birth Unit Design project was a 2012 Australian ethnographic study that used video recording to investigate the physical design features in the hospital birthing space that might influence both verbal and non-verbal communication and the experiences of childbearing women, midwives and supporters. Participants and research context: Six women, 11 midwives and 11 childbirth supporters were filmed during the women's labours in hospital birth units and interviewed 6 weeks later. Ethical considerations: The study was approved by an Australian Health Research Ethics Committee after a protracted process of negotiation. FINDINGS: The ethics committee was influenced by a traditional view of research as based on scientific experiments resulting in a poor understanding of video-ethnographic research, a paradigmatic view of the politics and practicalities of modern childbirth processes, a desire to protect institutions from litigation, and what we perceived as a paternalistic approach towards protecting participants, one that was at odds with our aim to facilitate situations in which women could make flexible, autonomous decisions about how they might engage with the research process. DISCUSSION: The perceived need for protection was overly burdensome and against the wishes of the participants themselves; ultimately, this limited the capacity of the study to improve care for women and babies. CONCLUSION: Recommendations are offered for those involved in ethical approval processes for qualitative research in childbirth settings. The complexity of issues within childbirth settings, as in most modern healthcare settings, should be analysed using a variety of research approaches, beyond efficacy-style randomised controlled trials, to expand and improve practice-based results.


Assuntos
Trabalho de Parto , Parto , Projetos de Pesquisa , Gravação em Vídeo/ética , Austrália , Tomada de Decisões , Doulas , Comissão de Ética , Feminino , Humanos , Consentimento Livre e Esclarecido , Entrevistas como Assunto , Tocologia , Gravidez , Privacidade , Gravação em Vídeo/legislação & jurisprudência
10.
Nature ; 540(7631): 104-108, 2016 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-27905442

RESUMO

The majority of the Earth's terrestrial carbon is stored in the soil. If anthropogenic warming stimulates the loss of this carbon to the atmosphere, it could drive further planetary warming. Despite evidence that warming enhances carbon fluxes to and from the soil, the net global balance between these responses remains uncertain. Here we present a comprehensive analysis of warming-induced changes in soil carbon stocks by assembling data from 49 field experiments located across North America, Europe and Asia. We find that the effects of warming are contingent on the size of the initial soil carbon stock, with considerable losses occurring in high-latitude areas. By extrapolating this empirical relationship to the global scale, we provide estimates of soil carbon sensitivity to warming that may help to constrain Earth system model projections. Our empirical relationship suggests that global soil carbon stocks in the upper soil horizons will fall by 30 ± 30 petagrams of carbon to 203 ± 161 petagrams of carbon under one degree of warming, depending on the rate at which the effects of warming are realized. Under the conservative assumption that the response of soil carbon to warming occurs within a year, a business-as-usual climate scenario would drive the loss of 55 ± 50 petagrams of carbon from the upper soil horizons by 2050. This value is around 12-17 per cent of the expected anthropogenic emissions over this period. Despite the considerable uncertainty in our estimates, the direction of the global soil carbon response is consistent across all scenarios. This provides strong empirical support for the idea that rising temperatures will stimulate the net loss of soil carbon to the atmosphere, driving a positive land carbon-climate feedback that could accelerate climate change.


Assuntos
Atmosfera/química , Ciclo do Carbono , Carbono/análise , Geografia , Aquecimento Global , Solo/química , Bases de Dados Factuais , Ecossistema , Retroalimentação , Modelos Estatísticos , Reprodutibilidade dos Testes , Temperatura
11.
HERD ; 9(3): 135-61, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26794236

RESUMO

OBJECTIVE: To explore inhibiting and facilitating design factors influencing childbirth supporters' experiences. BACKGROUND: Birthing women benefit from the continuous, cooperative presence of supporters. However, little research has investigated how birth room design facilitates or inhibits supporters' role navigation. METHODS: We conducted an exploratory video ethnographic single case study of childbirth supporters' experiences, within an Australian hospital birth environment. Video, field notes, and video-cued reflexive interviews with the woman, her midwives, and supporters were thematically analyzed using ethnographic/symbolic interactionist perspectives to frame supporters' understandings. RESULTS: Findings suggest supporters' experiences are complex, made more complicated by sparse understanding or accommodation of their needs in the built environment. Supporters' presence and roles are not facilitated by the physical space; they experience "an unbelonging paradox" of being needed, yet uncertain and "in the way" during "tenuous nest-building" activities. CONCLUSIONS: Suggested design guidelines to facilitate supporters' well-being and their roles in designed hospital birth spaces are provided.


Assuntos
Centros de Assistência à Gravidez e ao Parto/normas , Doulas/psicologia , Arquitetura Hospitalar/normas , Enfermeiros Obstétricos/psicologia , Parto/psicologia , Gestantes/psicologia , Adulto , Austrália , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gravidez , Apoio Social
12.
Tijdschr Psychiatr ; 55(5): 325-35, 2013.
Artigo em Holandês | MEDLINE | ID: mdl-23696335

RESUMO

BACKGROUND: The Dutch government and the Council for public prosecutions consider aggression against and violence directed against public officers and care workers as unacceptable. But what is the attitude of these official bodies to violence directed against mental health care workers? AIM: To examine the nature and the prevalence of violence against mental health care professionals and the possible judicial consequences of this violence. METHOD: Dutch mental health professionals who work in the psychiatric hospitals and clinics were asked to fill in an online questionnaire about their experiences, over the past five years, of violence perpetrated by patients. RESULTS: The 1534 respondents had encountered violence regularly in the course of their work. Some of the violence was of a very serious nature and sometimes had severe consequences. Only a small number of the violent incidents were reported to the police and ultimately brought to court. The victims were poorly informed about the possible judicial consequences of the violence they had encountered. CONCLUSION: Not only should the mental health institutes counsel and inform the employees who have been victims of violence, they should also promote the development and implementation of an effective prosecution policy.


Assuntos
Agressão , Vítimas de Crime/legislação & jurisprudência , Serviços de Saúde Mental , Violência/estatística & dados numéricos , Local de Trabalho/estatística & dados numéricos , Adulto , Idoso , Vítimas de Crime/estatística & dados numéricos , Dissidências e Disputas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos , Saúde Ocupacional , Relações Médico-Paciente , Prevalência , Recursos Humanos , Adulto Jovem
13.
Phys Rev Lett ; 108(13): 135006, 2012 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-22540711

RESUMO

We have imaged hard x-ray (>100 keV) bremsstrahlung emission from energetic electrons slowing in a plastic ablator shell during indirectly driven implosions at the National Ignition Facility. We measure 570 J in electrons with E>100 keV impinging on the fusion capsule under ignition drive conditions. This translates into an acceptable increase in the adiabat α, defined as the ratio of total deuterium-tritium fuel pressure to Fermi pressure, of 3.5%. The hard x-ray observables are consistent with detailed radiative-hydrodynamics simulations, including the sourcing and transport of these high energy electrons.

14.
Int J Law Psychiatry ; 34(5): 317-23, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21924773

RESUMO

The number of (severe) violent incidents against staff caused by psychiatric inpatients is high. Victims often do not report these incidents to the police, because of various reasons. But if they do report these incidents, the judicial authorities are often reluctant in prosecuting and convicting these patients. The central question in this article is 'in which cases is it appropriate to prosecute assaultive psychiatric patients?' In order to identify the influential factors in the decision in respectively reporting, prosecuting and convicting psychiatric patients who assault staff, a literature review has been performed. On the basis of this literature it is advised to report and investigate a case when the incident resulted in severe injury, the incident is a sexual offence, or when a patient repetitively causes violent incidents. Moreover, it appears that, although large amount of studies has been published on violence in psychiatry, the prosecution of violent psychiatric patients has hardly received any attention in the international literature. Empirical studies on this subject are suggested, in order to develop a uniform policy, which is embraced by all parties involved.


Assuntos
Pacientes Internados/psicologia , Aplicação da Lei , Serviços de Saúde Mental , Exposição Ocupacional/legislação & jurisprudência , Auxiliares de Psiquiatria , Violência , Feminino , Pessoal de Saúde , Humanos , Masculino , Recursos Humanos
15.
Poult Sci ; 90(3): 694-700, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21325244

RESUMO

Three poultry chilling methods, namely, water chilling (WC), air chilling (AC), and evaporative air chilling (EAC), were compared to evaluate their effects on broiler breast meat quality and consumer sensory characteristics. A total of 189 birds were processed with 1 of the 3 chilling methods. One-third of the birds were hard scalded (57.7°C, 120 s) and subjected to WC (an ice slurry immersion at 0°C). The remaining birds were soft scalded (50°C, 220 s) and randomly assigned to either AC (blowing air, 1.0 m/s) or EAC (blowing air plus each carcass sprayed with 0.5 L of 0.4°C water) in a chilling room (0.9 ± 0.4°C). Water chilling reduced the carcass temperature most efficiently (57 min), whereas AC and EAC were the least (125 min) and intermediate (93 min) in efficiency, respectively. No significant difference was found among the chilling methods in moisture content, cooking yield, and shear force of deskinned breast fillets stored overnight. However, the pH (5.6) of 24-h stored fillets was higher in WC fillets than in AC (5.5) and EAC (5.5) fillets. For the surface color of skinless breasts, WC carcasses showed a higher Commission Internationale de l'Éclairage (CIE) L* value than AC or EAC carcasses, whereas AC carcasses exhibited more redness (higher CIE a*) and yellowness (higher CIE b*) than the other 2 chilling methods. When raw breast meat was made into cooked gels, no significant difference was observed in cooking loss, moisture content, shear stress, and shear strain, regardless of the chilling method. In consumer sensory evaluations, AC breasts had a higher juiciness score than did WC and EAC breasts, but no significant difference was found for flavor, texture, and overall acceptability.


Assuntos
Manipulação de Alimentos/métodos , Carne/normas , Refrigeração/métodos , Animais , Inteligência Artificial , Galinhas , Comportamento do Consumidor , Humanos
16.
Ecology ; 89(10): 2700-11, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18959308

RESUMO

The biodiversity scaling metrics widely studied in macroecology include the species-area relationship (SAR), the scale-dependent species-abundance distribution (SAD), the distribution of masses or metabolic energies of individuals within and across species, the abundance-energy or abundance-mass relationship across species, and the species-level occupancy distributions across space. We propose a theoretical framework for predicting the scaling forms of these and other metrics based on the state-variable concept and an analytical method derived from information theory. In statistical physics, a method of inference based on information entropy results in a complete macro-scale description of classical thermodynamic systems in terms of the state variables volume, temperature, and number of molecules. In analogy, we take the state variables of an ecosystem to be its total area, the total number of species within any specified taxonomic group in that area, the total number of individuals across those species, and the summed metabolic energy rate for all those individuals. In terms solely of ratios of those state variables, and without invoking any specific ecological mechanisms, we show that realistic functional forms for the macroecological metrics listed above are inferred based on information entropy. The Fisher log series SAD emerges naturally from the theory. The SAR is predicted to have negative curvature on a log-log plot, but as the ratio of the number of species to the number of individuals decreases, the SAR becomes better and better approximated by a power law, with the predicted slope z in the range of 0.14-0.20. Using the 3/4 power mass-metabolism scaling relation to relate energy requirements and measured body sizes, the Damuth scaling rule relating mass and abundance is also predicted by the theory. We argue that the predicted forms of the macroecological metrics are in reasonable agreement with the patterns observed from plant census data across habitats and spatial scales. While this is encouraging, given the absence of adjustable fitting parameters in the theory, we further argue that even small discrepancies between data and predictions can help identify ecological mechanisms that influence macroecological patterns.


Assuntos
Biodiversidade , Entropia , Modelos Biológicos , Modelos Teóricos , Animais , Biomassa , Demografia , Ecossistema , Densidade Demográfica , Dinâmica Populacional , Especificidade da Espécie
17.
J Vet Intern Med ; 15(1): 7-13, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11215916

RESUMO

The objectives of this study were to investigate the prevalence of food sensitivity in cats with chronic idiopathic gastrointestinal problems, to identify the food ingredients responsible, and to characterize the clinical features. Seventy cats that presented for chronic gastrointestinal signs underwent diagnostic investigation. Fifty-five cats had idiopathic problems and were entered into the study. Diagnosis of food sensitivity was made by dietary elimination-challenge studies by using commercial selected-protein diets as the elimination diet. Sixteen (29%) of the 55 cats with chronic idiopathic gastrointestinal problems were diagnosed as food sensitive. The clinical signs of another 11 cats (20%) resolved on the elimination diet but did not recur after challenge with their previous diet. The foods or food ingredients responsible for the clinical signs were dietary staples. Fifty percent of affected cats were sensitive to more than 1 food ingredient. The clinical feature most suggestive of food sensitivity was concurrent occurrence of gastrointestinal and dermatological signs. Weight loss occurred in 11 of the affected cats, and large-bowel diarrhea was more common than small-bowel diarrhea. Assay of serum antigen-specific immunoglobulin E (IgE) had limited value as a screening test, and gastroscopic food sensitivity testing was not helpful. In conclusion, adverse reactions to dietary staples were common in this population of cats, and they responded well to selected-protein diets. Diagnosis requires dietary elimination-challenge trials and cannot be made on the basis of clinical signs, routine clinicopathological data, serum antigen-specific IgE assay, gastroscopic food sensitivity testing, or gastrointestinal biopsy.


Assuntos
Ração Animal/efeitos adversos , Doenças do Gato/diagnóstico , Doenças do Gato/epidemiologia , Proteínas Alimentares/administração & dosagem , Hipersensibilidade Alimentar/veterinária , Gastroenteropatias/veterinária , Animais , Doenças do Gato/terapia , Gatos , Diarreia/veterinária , Feminino , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/epidemiologia , Hipersensibilidade Alimentar/terapia , Gastroenteropatias/diagnóstico , Gastroenteropatias/epidemiologia , Gastroenteropatias/terapia , Imunoglobulina E/análise , Masculino , Prevalência , Vômito/veterinária , Redução de Peso
18.
Am Nat ; 157(4): 374-86, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18707248

RESUMO

Patterns in the relationships among the range, abundance, and distribution of species within a biome are of fundamental interest in ecology. A self-similarity condition, imposed at the community level and previously demonstrated to lead to the power-law form of the species-area relationship, is extended to the species level and shown to predict testable power-law relationships between range size and both species abundance and area of census cell across scales of spatial resolution. The predicted slopes of plots of log(range size) versus log(abundance) are shown to be in good agreement with data from British breeding bird and mammal censuses and with data on the distribution of fern species in old-growth forest. The predicted slopes of plots of log(range size) versus log (area of census cell) are consistent with the limited available data for British plant species. Self-similarity provides a testable theoretical framework for a unified understanding of patterns among the range, abundance, and distribution of species.

19.
J Vet Intern Med ; 14(6): 598-608, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11110381

RESUMO

The efficacy, safety, and metabolic consequences of rapid weight loss in privately owned obese cats by means of a canned weight-reduction diet and the influence of orally administered L-carnitine on rate of weight loss, routine clinical evaluations, hepatic ultrasonography, plasma amino acid profiles, and carnitine analytes were evaluated. A double-blinded placebo-controlled design was used with cats randomly divided into 2 groups: Group 1 (n = 14) received L-carnitine (250 mg PO q24h) in aqueous solution and group 2 (n = 10) received an identical-appearing water placebo. Median obesity (body condition scores and percentage ideal body weight) in each group was 25%. Caloric intake was restricted to 60% of maintenance energy requirements (60 kcal/kg) for targeted ideal weight. The reducing formula was readily accepted by all cats. Significant weight loss was achieved by week 18 in each group without adverse effects (group 1 = 23.7%, group 2 = 19.6%). Cats receiving carnitine lost weight at a significantly faster rate (P < .05). Significant increases in carnitine values developed in each group (P < .02). However, significantly higher concentrations of all carnitine moieties and a greater percentage of acetylcarnitine developed in cats of group 1 (P < .01). The dietary formula and described reducing strategy can safely achieve a 20% weight reduction within 18 weeks in obese cats. An aqueous solution of L-carnitine (250 mg PO q12h) was at least partially absorbed, was nontoxic, and significantly increased plasma carnitine analyte concentrations as well as rate of weight loss.


Assuntos
Carnitina/administração & dosagem , Doenças do Gato/dietoterapia , Dieta Redutora/veterinária , Obesidade/veterinária , Redução de Peso , Ácido 3-Hidroxibutírico/sangue , Abdome/fisiologia , Aminoácidos/sangue , Ração Animal , Animais , Animais Domésticos , Disponibilidade Biológica , Análise Química do Sangue/veterinária , Carnitina/sangue , Carnitina/farmacocinética , Doenças do Gato/metabolismo , Gatos , Suplementos Nutricionais , Método Duplo-Cego , Ingestão de Alimentos , Feminino , Fígado/diagnóstico por imagem , Masculino , Obesidade/dietoterapia , Obesidade/metabolismo , Espectrometria de Massas de Bombardeamento Rápido de Átomos/veterinária , Estatísticas não Paramétricas , Ultrassonografia
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