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1.
Nat Commun ; 14(1): 7404, 2023 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-37973878

RESUMO

Understanding how tropical systems have responded to large-scale climate change, such as glacial-interglacial oscillations, and how human impacts have altered those responses is key to current and future ecology. A sedimentary record recovered from Lake Junín, in the Peruvian Andes (4085 m elevation) spans the last 670,000 years and represents the longest continuous and empirically-dated record of tropical vegetation change to date. Spanning seven glacial-interglacial oscillations, fossil pollen and charcoal recovered from the core showed the general dominance of grasslands, although during the warmest times some Andean forest trees grew above their modern limits near the lake. Fire was very rare until the last 12,000 years, when humans were in the landscape. Here we show that, due to human activity, our present interglacial, the Holocene, has a distinctive vegetation composition and ecological trajectory compared with six previous interglacials. Our data reinforce the view that modern vegetation assemblages of high Andean grasslands and the presence of a defined tree line are aspects of a human-modified landscape.


Assuntos
Florestas , Árvores , Humanos , Árvores/fisiologia , Pólen , Fósseis , Mudança Climática , Ecossistema
2.
Nature ; 607(7918): 301-306, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35831604

RESUMO

Our understanding of the climatic teleconnections that drove ice-age cycles has been limited by a paucity of well-dated tropical records of glaciation that span several glacial-interglacial intervals. Glacial deposits offer discrete snapshots of glacier extent but cannot provide the continuous records required for detailed interhemispheric comparisons. By contrast, lakes located within glaciated catchments can provide continuous archives of upstream glacial activity, but few such records extend beyond the last glacial cycle. Here a piston core from Lake Junín in the uppermost Amazon basin provides the first, to our knowledge, continuous, independently dated archive of tropical glaciation spanning 700,000 years. We find that tropical glaciers tracked changes in global ice volume and followed a clear approximately 100,000-year periodicity. An enhancement in the extent of tropical Andean glaciers relative to global ice volume occurred between 200,000 and 400,000 years ago, during sustained intervals of regionally elevated hydrologic balance that modified the regular approximately 23,000-year pacing of monsoon-driven precipitation. Millennial-scale variations in the extent of tropical Andean glaciers during the last glacial cycle were driven by variations in regional monsoon strength that were linked to temperature perturbations in Greenland ice cores1; these interhemispheric connections may have existed during previous glacial cycles.

3.
Public Health ; 184: 41-45, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32402593

RESUMO

OBJECTIVES: Gambling availability, participation and expenditure have increased markedly in many parts of the world. This is expected to continue and have significant public health impacts. The purpose of this study is to examine the changing epidemiology of gambling and gambling-related harm and its implications for public health policy and practice. STUDY DESIGN: This is a narrative review. METHODS: Relevant literature, with an emphasis on recent studies and reviews, was examined to identify major epidemiological findings and trends. RESULTS: Greater gambling availability was associated with an increase in participation and expenditure and a rise in at-risk and problem gambling prevalence rates. While problem gamblers experience considerable harm, most harm arises from non-problem gamblers. These harms are substantial and impact disproportionately marginalised populations. The burden of harm is mainly due to financial problems, damage to relationships and health, psychological distress and adverse effects on work and education. Although at-risk and problem gambling rates initially increased in many jurisdictions, they subsequently declined. More recently, in some jurisdictions, while gambling participation has declined, at-risk and problem gambling rates have plateaued. This at least partly is due to an accumulating 'pool' of past problem gamblers who are highly prone to relapse and other vulnerable groups continuing to experience heavy gambling exposure. CONCLUSION: Public health policies need to focus strongly on reducing exposure to more 'toxic' gambling forms as well as increasing the availability of interventions to assist at-risk and problem gamblers and prevent relapse. Policies and programmes are likely to be more effective if population heterogeneity is considered, and they also address the wide range of modifiable risk and protective factors at individual, community and societal levels. Many of these are shared with other health and social morbidities.


Assuntos
Jogo de Azar/epidemiologia , Jogo de Azar/prevenção & controle , Humanos , Prática de Saúde Pública , Política Pública
4.
Public Health ; 184: 56-59, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32402594

RESUMO

OBJECTIVES: There has been unprecedented growth in commercial gambling. Increasingly gambling has migrated to the Internet and become readily accessible via mobile devices. Gambling disorder and gambling-related harm present a significant global public health challenge. To date, few jurisdictions have included gambling in health policies and addressed gambling-related harm within a comprehensive public health framework. The purpose of this study is to examine recent developments at the global level that may change this. STUDY DESIGN: This is a narrative review and examination of meeting content and outcomes. METHODS: Relevant literature was reviewed, and the content and outcomes of recent International Think Tank on Gambling Research, Policy and Practice and World Health Organization (WHO) meetings were identified, summarised and discussed. RESULTS: Although gambling disorder was included in the International Statistical Classification of Diseases in 1975, relatively little attention has been given to assessing wider gambling-related harms and addressing them within a public health framework. In recent years, this has changed with the first gambling studies to use burden of disease methodologies and the development of harm classifications and conceptual frameworks. This research has strengthened calls for gambling to be included in public health agendas. While few member states have done this, in the past few years gambling has received increased attention from the WHO. This includes its placement alongside alcohol and drugs in 2017 and 2019 WHO global forums and annual WHO meetings on public health implications of addictive behaviours. These and planned WHO meetings and activities are laying the groundwork for a WHO international gambling programme and work plan. CONCLUSION: A significant start has been made to address gambling disorder and gambling-related harm as an important global health issue. This has potential to encourage member states to explicitly include gambling in national and subnational public health plans. However, this progress may be precarious and is likely to require concerted advocacy and support from academic and other civil society organisations to sustain.


Assuntos
Jogo de Azar/epidemiologia , Jogo de Azar/prevenção & controle , Saúde Global , Humanos , Prática de Saúde Pública , Organização Mundial da Saúde
5.
Bull Math Biol ; 82(5): 56, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32356149

RESUMO

As zebrafish develop, black and gold stripes form across their skin due to the interactions of brightly colored pigment cells. These characteristic patterns emerge on the growing fish body, as well as on the anal and caudal fins. While wild-type stripes form parallel to a horizontal marker on the body, patterns on the tailfin gradually extend distally outward. Interestingly, several mutations lead to altered body patterns without affecting fin stripes. Through an exploratory modeling approach, our goal is to help better understand these differences between body and fin patterns. By adapting a prior agent-based model of cell interactions on the fish body, we present an in silico study of stripe development on tailfins. Our main result is a demonstration that two cell types can produce stripes on the caudal fin. We highlight several ways that bone rays, growth, and the body-fin interface may be involved in patterning, and we raise questions for future work related to pattern robustness.


Assuntos
Modelos Biológicos , Peixe-Zebra/crescimento & desenvolvimento , Nadadeiras de Animais/anatomia & histologia , Nadadeiras de Animais/citologia , Nadadeiras de Animais/crescimento & desenvolvimento , Animais , Padronização Corporal/genética , Padronização Corporal/fisiologia , Comunicação Celular/fisiologia , Diferenciação Celular/fisiologia , Movimento Celular/fisiologia , Simulação por Computador , Epitélio/crescimento & desenvolvimento , Conceitos Matemáticos , Mutação , Pigmentação da Pele/genética , Pigmentação da Pele/fisiologia , Análise de Sistemas , Peixe-Zebra/genética , Peixe-Zebra/fisiologia
6.
J Child Orthop ; 12(3): 273-278, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29951127

RESUMO

PURPOSE: The Ponseti method of treatment is the standard of care for idiopathic clubfoot. Following serial casting, percutaneous tendo-Achilles tenotomy (TAT) is performed to correct residual equinus. This procedure can be performed in either the outpatient clinic or the operating room. The purpose of this study was to evaluate the expense of this procedure by examining hospital charges in both settings. METHODS: We retrospectively reviewed charts of 382 idiopathic clubfoot patients with a mean age of 2.4 months (0.6 to 26.6) treated with the Ponseti method at three institutions. Patients were divided into three groups depending on the setting for the TAT procedure: 140 patients in the outpatient clinic (CL), 219 in the operating room with discharge following the procedure (OR) and 23 in the operating room with admission to hospital for observation (OR+). Medical records were reviewed to analyze age, deformity, perioperative complications and specific time spent in each setting. Hospital charges for all three groups were standardized to one institution's charge structure. RESULTS: Charges among the three groups undergoing TAT (CL, OR, OR+) were found to be significantly different ($3840.60 versus $7962.30 versus $9110.00, respectively; p ≤ 0.001), and remained significant when separating unilateral and bilateral deformities (p < 0.001). There were nine total perioperative complications (six returns to the ER and three unexpected admissions to the hospital): five (2.3%) in the OR group, four (17.4%) in the OR+ group and none in the CL group. The OR+ group statistically had a higher rate of complications compared with the other two groups (p = 0.006). The total event time of the CL group was significantly shorter compared with the OR and OR+ groups (129.1, 171.7 and 1571.6 minutes respectively; p < 0.001). CONCLUSION: Hospital charges and total event time were significantly less when percutaneous TAT was performed in the outpatient clinic compared with the operating room. In addition, performing the procedure in clinic was associated with the lowest rate of complications. LEVEL OF EVIDENCE: Therapeutic, Level III.

7.
BMJ Open ; 7(3): e013490, 2017 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-28255094

RESUMO

INTRODUCTION: The primary purpose of this study is to evaluate the relative effectiveness of 2 of the best developed and most promising forms of therapy for problem gambling, namely face-to-face motivational interviewing (MI) combined with a self-instruction booklet (W) and follow-up telephone booster sessions (B; MI+W+B) and face-to-face cognitive-behavioural therapy (CBT). METHODS AND ANALYSIS: This project is a single-blind pragmatic randomised clinical trial of 2 interventions, with and without the addition of relapse-prevention text messages. Trial assessments take place pretreatment, at 3 and 12 months. A total of 300 participants will be recruited through a community treatment agency that provides services across New Zealand and randomised to up to 10 face-to-face sessions of CBT or 1 face-to-face session of MI+W+up to 5 B. Participants will also be randomised to 9 months of postcare text messaging. Eligibility criteria include a self-perception of having a current gambling problem and a willingness to participate in all components of the study (eg, read workbook). The statistical analysis will use an intent-to-treat approach. Primary outcome measures are days spent gambling and amount of money spent per day gambling in the prior month. Secondary outcome measures include problem gambling severity, gambling urges, gambling cognitions, mood, alcohol, drug use, tobacco, psychological distress, quality of life, health status and direct and indirect costs associated with treatment. ETHICS AND DISSEMINATION: The research methods to be used in this study have been approved by the Ministry of Health, Health and Disability Ethics Committees (HDEC) 15/CEN/99. The investigators will provide annual reports to the HDEC and report any adverse events to this committee. Amendments will also be submitted to this committee. The results of this trial will be submitted for publication in peer-reviewed journals and as a report to the funding body. Additionally, the results will be presented at national and international conferences. TRIAL REGISTRATION NUMBER: ACTRN12615000637549.


Assuntos
Comportamento Aditivo/terapia , Terapia Cognitivo-Comportamental/métodos , Jogo de Azar/terapia , Entrevista Motivacional , Folhetos , Envio de Mensagens de Texto , Feminino , Humanos , Masculino , Projetos de Pesquisa , Método Simples-Cego , Telefone
8.
Addict Behav ; 39(12): 1713-7, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25117847

RESUMO

The primary aim of this study was to explore the prevalence and patterns of family violence in treatment-seeking problem gamblers. Secondary aims were to identify the prevalence of problem gambling in a family violence victimisation treatment sample and to explore the relationship between problem gambling and family violence in other treatment-seeking samples. Clients from 15 Australian treatment services were systematically screened for problem gambling using the Brief Bio-Social Gambling Screen and for family violence using single victimisation and perpetration items adapted from the Hurt-Insulted-Threatened-Screamed (HITS): gambling services (n=463), family violence services (n=95), alcohol and drug services (n=47), mental health services (n=51), and financial counselling services (n=48). The prevalence of family violence in the gambling sample was 33.9% (11.0% victimisation only, 6.9% perpetration only, and 16.0% both victimisation and perpetration). Female gamblers were significantly more likely to report victimisation only (16.5% cf. 7.8%) and both victimisation and perpetration (21.2% cf. 13.0%) than male gamblers. There were no other demographic differences in family violence prevalence estimates. Gamblers most commonly endorsed their parents as both the perpetrators and victims of family violence, followed by current and former partners. The prevalence of problem gambling in the family violence sample was 2.2%. The alcohol and drug (84.0%) and mental health (61.6%) samples reported significantly higher rates of any family violence than the gambling sample, while the financial counselling sample (10.6%) reported significantly higher rates of problem gambling than the family violence sample. The findings of this study support substantial comorbidity between problem gambling and family violence, although this may be accounted for by a high comorbidity with alcohol and drug use problems and other psychiatric disorders. They highlight the need for routine screening, assessment and management of problem gambling and family violence in a range of services.


Assuntos
Violência Doméstica/estatística & dados numéricos , Jogo de Azar/epidemiologia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Comorbidade , Estudos Transversais , Feminino , Jogo de Azar/terapia , Humanos , Masculino , Transtornos Mentais/epidemiologia , Transtornos Mentais/terapia , Pessoa de Meia-Idade , Prevalência , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/terapia , Adulto Jovem
10.
Health Phys ; 106(5 Suppl 2): S65-70, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24667387

RESUMO

Response to a large-scale radiological incident could require timely medical interventions to minimize radiation casualties. Proper medical care requires knowing the victim's radiation dose. When physical dosimetry is absent, radiation-specific chromosome aberration analysis can serve to estimate the absorbed dose in order to assist physicians in the medical management of radiation injuries. A mock exercise scenario was presented to six participating biodosimetry laboratories as one individual acutely exposed to Co under conditions suggesting whole-body exposure. The individual was not wearing a dosimeter and within 2-3 h of the incident began vomiting. The individual also had other medical symptoms indicating likelihood of a significant dose. Physicians managing the patient requested a dose estimate in order to develop a treatment plan. Participating laboratories in North and South America, Europe, and Asia were asked to evaluate more than 800 electronic images of metaphase cells from the patient to determine the dicentric yield and calculate a dose estimate with 95% confidence limits. All participants were blind to the physical dose until after submitting their estimates based on the dicentric chromosome assay (DCA). The exercise was successful since the mean biological dose estimate was 1.89 Gy whereas the actual physical dose was 2 Gy. This is well within the requirements for guidance of medical management. The exercise demonstrated that the most labor-intensive step in the entire process (visual evaluation of images) can be accelerated by taking advantage of world-wide expertise available on the Internet.


Assuntos
Bioensaio/métodos , Aberrações Cromossômicas/efeitos da radiação , Cromossomos Humanos/efeitos da radiação , Internet/estatística & dados numéricos , Laboratórios/normas , Incidentes com Feridos em Massa/prevenção & controle , Lesões por Radiação/diagnóstico , Células Cultivadas , Cromossomos Humanos/genética , Radioisótopos de Cobalto/efeitos adversos , Relação Dose-Resposta à Radiação , Humanos , Processamento de Imagem Assistida por Computador , Linfócitos/efeitos da radiação , Metáfase/efeitos da radiação , Lesões por Radiação/genética , Lesões por Radiação/prevenção & controle , Liberação Nociva de Radioativos/prevenção & controle , Radiometria
12.
AJNR Am J Neuroradiol ; 35(1): 191-5, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23886739

RESUMO

BACKGROUND AND PURPOSE: Contrast is used in CT-guided epidural steroid injections to ensure proper needle placement. Once injected, undiluted contrast often obscures the needle, hindering subsequent repositioning. The purpose of this investigation was to establish the optimal contrast dilution for CT-guided epidural steroid injections. MATERIALS AND METHODS: This investigation consisted of an initial phantom study, followed by a prospective, randomized, single-center trial assessing a range of contrast dilutions. In the phantom study, a phantom housing a chamber containing a 22-gauge needle and various dilutions of contrast was scanned, and images were evaluated for needle visibility. On the basis of these results, concentrations of 66, 100, 133, and 150 mg/mL iodine were selected for evaluation in a clinical study. Patients presenting for CT-guided epidural steroid injections were randomly assigned to a contrast dilution, and images from the procedure were evaluated by 2 readers blinded to the contrast assignment. Needle visibility was scored by use of a 5-point scale. RESULTS: In the phantom study, the needle was not visible at contrast concentrations of ≥133 mg/mL. In the clinical study, needle visibility was strongly associated with contrast concentration (P < .0001). Significant improvements in visibility were found in 66 mg/mL and 100 mg/mL compared with higher iodine concentrations; no difference was found comparing 66 mg/mL with 100 mg/mL iodine. Neither injection location (cervical versus lumbar) nor technique (interlaminar versus transforaminal) influenced visibility scores. CONCLUSIONS: For CT-guided epidural steroid injections, the optimal contrast concentration is 66-100 mg/mL iodine. Because these concentrations are not commercially available, proceduralists must dilute their contrast for such procedures.


Assuntos
Iodo/administração & dosagem , Mielografia/métodos , Intensificação de Imagem Radiográfica/métodos , Radiografia Intervencionista/métodos , Esteroides/administração & dosagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Meios de Contraste/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Humanos , Injeções Epidurais/métodos , Masculino , Pessoa de Meia-Idade , Mielografia/instrumentação , Imagens de Fantasmas , Radiografia Intervencionista/instrumentação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/instrumentação , Adulto Jovem
13.
Health Educ Res ; 28(3): 375-91, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23660461

RESUMO

The most effective woman-initiated method to prevent HIV/sexually transmitted infections is the female condom (FC). Yet, FCs are often difficult to find and denigrated or ignored by community health and service providers. Evidence increasingly supports the need to develop and test theoretically driven, multilevel interventions using a community-empowerment framework to promote FCs in a sustained way. We conducted a study in a midsized northeastern US city (2009-2013) designed to create, mobilize and build capacity of a community group to develop and implement multilevel interventions to increase availability, accessibility and support for FCs in their city. The Community Action and Advocacy Board (CAAB) designed and piloted interventions concurrently targeting community, organizational and individual levels. Ethnographic observation of the CAAB training and intervention planning and pilot implementation sessions documented the process, preliminary successes, challenges and limitations of this model. The CAAB demonstrated ability to conceptualize, plan and initiate multilevel community change. However, challenges in group decision-making and limitations in members' availability or personal capacity constrained CAAB processes and intervention implementation. Lessons from this experience could inform similar efforts to mobilize, engage and build capacity of community coalitions to increase access to and support for FCs and other novel effective prevention options for at-risk women.


Assuntos
Participação da Comunidade , Preservativos Femininos , Defesa do Paciente , Participação da Comunidade/métodos , Preservativos Femininos/estatística & dados numéricos , Preservativos Femininos/provisão & distribuição , Feminino , Humanos , Meio-Oeste dos Estados Unidos , Estudos de Casos Organizacionais
14.
Interface Focus ; 3(1): 20120036, 2013 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-24427509

RESUMO

The development of efficient and commercially viable bioprocesses is essential for reducing the need for fossil-derived products. Increasingly, pharmaceuticals, fuel, health products and precursor compounds for plastics are being synthesized using bioprocessing routes as opposed to more traditional chemical technologies. Production vessels or reactors are required for synthesis of crude product before downstream processing for extraction and purification. Reactors are operated either in discrete batches or, preferably, continuously in order to reduce waste, cost and energy. This review describes the oscillatory baffled reactor (OBR), which, generally, has a niche application in performing 'long' processes in plug flow conditions, and so should be suitable for various bioprocesses. We report findings to suggest that OBRs could increase reaction rates for specific bioprocesses owing to low shear, good global mixing and enhanced mass transfer compared with conventional reactors. By maintaining geometrical and dynamic conditions, the technology has been proved to be easily scaled up and operated continuously, allowing laboratory-scale results to be easily transferred to industrial-sized processes. This is the first comprehensive review of bioprocessing using OBRs. The barriers facing industrial adoption of the technology are discussed alongside some suggested strategies to overcome these barriers. OBR technology could prove to be a major aid in the development of commercially viable and sustainable bioprocesses, essential for moving towards a greener future.

15.
Radiat Res ; 172(6): 746-52, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19929421

RESUMO

The international radiation biodosimetry community has recently been engaged in activities focused on establishing cooperative networks for biodosimetric triage for radiation emergency scenarios involving mass casualties. To this end, there have been several recent publications in the literature regarding the potential for shared scoring in such an accident or incident. We present details from a medical irradiation case where two independently validated laboratories found very different yields of dicentric chromosome aberrations. The potential reasons for this disparity are discussed, and the actual reason is identified as being the partial-body nature of the radiation exposure combined with differing criteria for metaphase selection. In the context of the recent networking activity, this report is intended to highlight the fact that shared scoring may produce inconsistencies and that further validation of the scoring protocols and experimental techniques may be required before the networks are prepared to deal satisfactorily with a radiological or nuclear emergency. Also, the findings presented here clearly demonstrate the limitations of the dicentric assay for estimating radiation doses after partial-body exposures and bring into question the usefulness of rapid "triage mode" scoring in such exposure scenarios.


Assuntos
Aberrações Cromossômicas , Cromossomos Humanos , Raios X , Humanos , Doses de Radiação
16.
Korean J Radiol ; 8(6): 506-11, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18071281

RESUMO

OBJECTIVE: The purpose of this study is to evaluate the airway dynamics of the upper airway as depicted on cine MRI in children with tracheotomy tubes during two states of airflow through the upper airway. MATERIALS AND METHODS: Sagittal fast gradient echo cine MR images of the supra-glottic airway were obtained with a 1.5T MRI scanner on seven children with tracheotomy tubes. Two sets of images were obtained with either the tubes capped or uncapped. The findings of the cine MRI were retrospectively reviewed. Volume segmentation of the cine images to compare the airway volume change over time (mean volume, standard deviation, normalized range, and coefficient of variance) was performed for the capped and uncapped tubes in both the nasopharynx and hypopharynx (Signed Rank Test). RESULTS: Graphical representation of the airway volume over time demonstrates a qualitative increased fluctuation in patients with the tracheotomy tube capped as compared to uncapped in both the nasopharyngeal and hypopharyngeal regions of interest. In the nasopharynx, the mean airway volume (capped 2.72 mL, uncapped 2.09 mL, p = 0.0313), the airway volume standard deviation (capped 0.42 mL, uncapped 0.20 mL, p = 0.0156), and the airway volume range (capped 2.10 mL, uncapped 1.09 mL, p = 0.0156) were significantly larger in the capped group of patients. In the hypopharynx, the airway volume standard deviation (capped 1.54 mL, uncapped 0.67 mL, p = 0.0156), and the airway volume range (capped 6.44 mL, uncapped 2.93 mL, p = 0.0156) were significantly larger in the capped tubes. The coefficient of variance (capped 0.37, uncapped 0.26, p = 0.0469) and the normalized range (capped 1.52, uncapped 1.09, p = 0.0313) were significantly larger in the capped tubes. CONCLUSION: There is a statistically significant change in airway dynamics in children with tracheotomy tubes when breathing via the airway as compared to breathing via the tracheotomy tube.


Assuntos
Hipofaringe/fisiologia , Imagem Cinética por Ressonância Magnética/métodos , Nasofaringe/fisiologia , Traqueostomia/instrumentação , Trabalho Respiratório/fisiologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Hipofaringe/anatomia & histologia , Processamento de Imagem Assistida por Computador , Masculino , Nasofaringe/anatomia & histologia , Estudos Retrospectivos , Fatores de Tempo
18.
J Nucl Med ; 48(11): 1796-9, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17942815

RESUMO

UNLABELLED: Small-animal imaging systems are often characterized using phantoms, which may not predict performance in clinical applications. An implantable synthetic SPECT lesion would facilitate characterization of lesion detectability in a living animal. METHODS: Anion-exchange columns with bed volumes of 100-300 nL were constructed from medical-grade polyvinyl chloride tubing and resin. The columns were tested in an excised mouse femur and implanted in the femur of a living mouse. Imaging was performed using a prototype dual-modality SPECT/CT system. RESULTS: Activity of 7.4-22.2 MBq (0.2-0.6 mCi) localized within the synthetic lesion. The synthetic lesions were reused multiple times. Mice tolerated the implanted columns without complications for up to 8 wk. CONCLUSION: A reusable, synthetic SPECT lesion was constructed and implanted in the femur of a living mouse. The synthetic lesion is useful for the development of imaging schemes and for more realistically evaluating imaging-system performance in the context of a living animal.


Assuntos
Fêmur/diagnóstico por imagem , Imagens de Fantasmas , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Animais , Camundongos , Cloreto de Polivinila , Próteses e Implantes , Tomografia Computadorizada por Raios X
19.
Proc Natl Acad Sci U S A ; 103(24): 8937-42, 2006 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-16740660

RESUMO

The underlying causes of late-Holocene climate variability in the tropics are incompletely understood. Here we report a 1,500-year reconstruction of climate history and glaciation in the Venezuelan Andes using lake sediments. Four glacial advances occurred between anno Domini (A.D.) 1250 and 1810, coincident with solar-activity minima. Temperature declines of -3.2 +/- 1.4 degrees C and precipitation increases of approximately 20% are required to produce the observed glacial responses. These results highlight the sensitivity of high-altitude tropical regions to relatively small changes in radiative forcing, implying even greater probable responses to future anthropogenic forcing.


Assuntos
Clima , Luz Solar , Temperatura , Clima Tropical , Sedimentos Geológicos , Camada de Gelo , Modelos Teóricos , Venezuela
20.
Neurology ; 66(7): 1016-20, 2006 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-16606912

RESUMO

OBJECTIVE: To determine whether the rate of clinical progression in Huntington disease (HD) is influenced by the size of the CAG expansion. METHODS: The dataset consisted of 3,402 examinations of 512 subjects seen through the Baltimore Huntington's Disease Center. Subjects were seen for a mean of 6.64 visits, with mean follow-up of 6.74 years. Subjects were administered the Quantified Neurological Examination, with its subsets the Motor Impairment and Chorea Scores, the Mini-Mental State Examination, and the HD Activities of Daily Living (ADL) Scale. RESULTS: In an analysis based on the Random Effects Model, CAG length was significantly associated with the rate of progression of all measures except chorea and ADL. There was a significant interaction term between CAG length and disease duration for all measures except chorea. Further graphical exploration of the data supported these linear models and suggested that subjects at the low end of the expanded CAG repeat range may experience a more benign late course. CONCLUSIONS: CAG repeat length has a small effect on rate of progression that may be clinically important over time. Individuals with the shortest expansions appear to have the best prognosis. These effects of the CAG length may be relevant in the analysis of clinical trials.


Assuntos
Doença de Huntington/genética , Doença de Huntington/fisiopatologia , Repetições de Trinucleotídeos/genética , Baltimore , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
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