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1.
Nature ; 630(8016): 447-456, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38839969

RESUMO

Increasing rates of autoimmune and inflammatory disease present a burgeoning threat to human health1. This is compounded by the limited efficacy of available treatments1 and high failure rates during drug development2, highlighting an urgent need to better understand disease mechanisms. Here we show how functional genomics could address this challenge. By investigating an intergenic haplotype on chr21q22-which has been independently linked to inflammatory bowel disease, ankylosing spondylitis, primary sclerosing cholangitis and Takayasu's arteritis3-6-we identify that the causal gene, ETS2, is a central regulator of human inflammatory macrophages and delineate the shared disease mechanism that amplifies ETS2 expression. Genes regulated by ETS2 were prominently expressed in diseased tissues and more enriched for inflammatory bowel disease GWAS hits than most previously described pathways. Overexpressing ETS2 in resting macrophages reproduced the inflammatory state observed in chr21q22-associated diseases, with upregulation of multiple drug targets, including TNF and IL-23. Using a database of cellular signatures7, we identified drugs that might modulate this pathway and validated the potent anti-inflammatory activity of one class of small molecules in vitro and ex vivo. Together, this illustrates the power of functional genomics, applied directly in primary human cells, to identify immune-mediated disease mechanisms and potential therapeutic opportunities.


Assuntos
Inflamação , Macrófagos , Proteína Proto-Oncogênica c-ets-2 , Humanos , Proteína Proto-Oncogênica c-ets-2/genética , Proteína Proto-Oncogênica c-ets-2/metabolismo , Macrófagos/metabolismo , Macrófagos/imunologia , Inflamação/genética , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/genética , Haplótipos/genética , Doenças Inflamatórias Intestinais/genética , Animais , Masculino , Feminino , Camundongos , Regulação da Expressão Gênica
2.
Hum Genet ; 137(9): 723-734, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30167848

RESUMO

Rare variants are thought to contribute to the genetics of inflammatory bowel disease (IBD), which is more common amongst the Ashkenazi Jewish (AJ) population. A family-based approach using exome sequencing of AJ individuals with IBD was employed with a view to identify novel rare genetic variants for this disease. Exome sequencing was performed on 960 Jewish individuals including 513 from 199 multiplex families with up to eight cases. Rare, damaging variants in loci prioritized by linkage analysis and those shared by multiple affected individuals within the same family were identified. Independent evidence of association of each variant with disease was assessed. A number of candidate variants were identified, including in genes involved in the immune system. The ability to achieve statistical significance in independent case/control replication data was limited by power and was only achieved for variants in the well-established Crohn's disease gene, NOD2. This work demonstrates the challenges of identifying disease-associated rare damaging variants from exome data, even amongst a favorable cohort of familial cases from a genetic isolate. Further research of the prioritized rare candidate variants is required to confirm their association with the disease.


Assuntos
Predisposição Genética para Doença , Variação Genética , Doenças Inflamatórias Intestinais/genética , Judeus/genética , Proteína Adaptadora de Sinalização NOD2/genética , Fases de Leitura Aberta , Estudos de Casos e Controles , Feminino , Ligação Genética , Humanos , Masculino , Linhagem , Análise de Sequência de DNA/métodos
4.
Scand J Rheumatol ; 47(1): 62-70, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28990485

RESUMO

OBJECTIVES: Systemic sclerosis (SSc) is heterogenous. The objectives of this study were to evaluate the purpose, strengths and limitations of existing SSc subset criteria, and identify ideas among experts about subsets. METHODS: We conducted semi-structured interviews with randomly sampled international SSc experts. The interview transcripts underwent an iterative process with text deconstructed to single thought units until a saturated conceptual framework with coding was achieved and respondent occurrence tabulated. Serial cross-referential analyses of clusters were developed. RESULTS: Thirty experts from 13 countries were included; 67% were male, 63% were from Europe and 37% from North America; median experience of 22.5 years, with a median of 55 new SSc patients annually. Three thematic clusters regarding subsetting were identified: research and communication; management; and prognosis (prediction of internal organ involvement, survival). The strength of the limited/diffuse system was its ease of use, however 10% stated this system had marginal value. Shortcomings of the diffuse/limited classification were the risk of misclassification, predictions/generalizations did not always hold true, and that the elbow or knee threshold was arbitrary. Eighty-seven percent use more than 2 subsets including: SSc sine scleroderma, overlap conditions, antibody-determined subsets, speed of progression, and age of onset (juvenile, elderly). CONCLUSIONS: We have synthesized an international view of the construct of SSc subsets in the modern era. We found a number of factors underlying the construct of SSc subsets. Considerations for the next phase include rate of change and hierarchal clustering (e.g. limited/diffuse, then by antibodies).


Assuntos
Medição de Risco/métodos , Escleroderma Sistêmico/diagnóstico , Adulto , Estudos Transversais , Progressão da Doença , Feminino , Humanos , Masculino , Prognóstico
5.
Aliment Pharmacol Ther ; 43(8): 910-923, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-26892328

RESUMO

BACKGROUND: Infliximab and adalimumab have established roles in inflammatory bowel disease (IBD) therapy. UK regulators mandate reassessment after 12 months' anti-TNF therapy for IBD, with consideration of treatment withdrawal. There is a need for more data to establish the relapse rates following treatment cessation. AIM: To establish outcomes following anti-TNF withdrawal for sustained remission using new data from a large UK cohort, and assimilation of all available literature for systematic review and meta-analysis. METHODS: A retrospective observational study was performed on 166 patients with IBD (146 with Crohn's disease (CD) and 20 with ulcerative colitis [UC) and IBD unclassified (IBDU)] withdrawn from anti-TNF for sustained remission. Meta-analysis was undertaken of all published studies incorporating 11 further cohorts totalling 746 patients (624 CD, 122 UC). RESULTS: Relapse rates in the UK cohort were 36% by 1 year and 56% by 2 years for CD, and 42% by 1 year and 47% by 2 years for UC/IBDU. Increased relapse risk in CD was associated with age at diagnosis [hazard ratio (HR) 2.78 for age <22 years], white cell count (HR 3.22 for >5.25 × 109 /L) and faecal calprotectin (HR 2.95 for >50 µg/g) at drug withdrawal. Neither continued immunomodulators nor endoscopic remission were predictors. In the meta-analysis, estimated 1-year relapse rates were 39% and 35% for CD and UC/IBDU respectively. Retreatment with anti-TNF was successful in 88% for CD and 76% UC/IBDU. CONCLUSIONS: Assimilation of all available data reveals remarkable homogeneity. Approximately one-third of patients with IBD flare within 12 months of withdrawal of anti-TNF therapy for sustained remission.


Assuntos
Colite Ulcerativa/tratamento farmacológico , Doença de Crohn/tratamento farmacológico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adalimumab/administração & dosagem , Adulto , Fezes/química , Feminino , Humanos , Fatores Imunológicos/uso terapêutico , Infliximab/administração & dosagem , Masculino , Modelos de Riscos Proporcionais , Recidiva , Estudos Retrospectivos , Fatores de Tempo
6.
Eur J Clin Microbiol Infect Dis ; 34(1): 13-18, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25097085

RESUMO

As scientific techniques for the detection of cytomegalovirus (CMV) improve, we are able to detect small amounts of CMV in the mucosal wall. As clinicians, we are unsure how to interpret the results of this novel test. There is controversy in the literature as to the significance of the detection of CMV in the gut. Whilst the importance of CMV and reactivation of the virus is clear in those patients such as allograft recipients with established immune compromise, the role is less clear in patients with less damaged immune systems. We explore whether the detection of CMV in such cases influences outcome and how it should be optimally managed. We discuss the optimal management of such cases, according to current guidelines, with a review of the literature.


Assuntos
Colite/diagnóstico , Colite/virologia , Infecções por Citomegalovirus/diagnóstico , Citomegalovirus/isolamento & purificação , Humanos , Mucosa Intestinal/virologia
7.
Eye (Lond) ; 28(10): 1218-22, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25081290

RESUMO

PURPOSE: To determine the effect of oral acetazolamide on lowering the peak and duration of intraocular pressure (IOP) rise in glaucoma and glaucoma suspect patients, following intravitreal injection of ranibizumab for neovascular age-related macular degeneration. METHODS: The study was an open-label, parallel, randomised, controlled trial (EudraCT Number: 2010-023037-35). Twenty-four glaucoma or glaucoma suspect patients received either 500 mg acetazolamide or no treatment 60-90 min before 0.5 mg ranibizumab. The primary outcome measure was the difference in IOP immediately after injection (T0) and 5, 10, and 30 min following injection. ANCOVA was used to compare groups, adjusting for baseline IOP. The study was powered to detect a 9-mm Hg difference at T0. RESULTS: The IOP at T0 was 2.3 mm Hg higher in the non-treated group (mean 44.5 mm Hg, range (19-86 mm Hg)) compared with the treated group (mean 42.2 mm Hg, range (25-58 mm Hg)), but was not statistically significant after adjusting for baseline IOP (P=0.440). At 30 min, IOP was 4.9 mm Hg higher in the non-treated group (mean 20.6 mm Hg, range (11-46 mm Hg)) compared with the treated group (mean 15.7 mm Hg, range (8-21 mm Hg)). This was statistically significant after adjusting for baseline IOP (P=0.013). CONCLUSIONS: Although the primary end points were not reached, 500 mg oral acetazolamide, 60-90 min before intravitreal injection, results in a statistically significant reduction in IOP at 3O min post injection. Prophylactic treatment may be considered as an option to minimise neuro-retinal rim damage in high-risk glaucoma patients who are most vulnerable to IOP spikes and undergoing repeated intravitreal injections of ranibizumab.


Assuntos
Acetazolamida/administração & dosagem , Inibidores da Angiogênese/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Inibidores da Anidrase Carbônica/administração & dosagem , Glaucoma/prevenção & controle , Pressão Intraocular/efeitos dos fármacos , Degeneração Macular Exsudativa/tratamento farmacológico , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Injeções Intravítreas , Masculino , Hipertensão Ocular/prevenção & controle , Soluções Oftálmicas , Ranibizumab , Tonometria Ocular , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores
8.
Eye (Lond) ; 27(5): 652-6, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23449510

RESUMO

PURPOSE: To describe the incidence and features of intraoperative retinal breaks caused by induction of posterior hyaloid face (PHF) separation during 23-gauge pars plana vitrectomy (PPV). METHODS: A prospective, consecutive, single surgeon, observational study of patients undergoing 23-gauge transconjunctival sutureless vitrectomy for macular pathology or floaters, was carried out between 2009 and 2011 at Calderdale Royal Hospital, UK. PHF separations were categorised as either suction induced or requiring membrane blue (DORC Limited) with suction (adherent). The outcome measure was dichotomised into retinal break or tear and no retinal break or tear. Forced entry and parsimonious multiple logistic regression analyses were conducted, using statistical software, to test for significance of association of the set of recorded factors and covariates with the dichotomised outcome measure. RESULTS: Data were collected and analysed from 137 patients. The incidence of iatrogenic retinal breaks associated with PHF separation during 23-gauge PPV was 18.2%. Under both forced entry and parsimonious multiple logistic regression models, the odds of a retinal break or tear reduce by about 3-4% for each increasing year of age. Findings also showed some substantive association in the forced entry model, with the odds of a retinal break or tear for adherent cases being around 3.8 times those for suction-only cases. CONCLUSIONS: Mechanical detachment of the PHF represents an important risk factor in the formation of retinal breaks. Particular care should be taken to examine intraoperatively for iatrogenic breaks in order to prevent missed breaks and subsequent rhegmatogenous retinal detachments.


Assuntos
Membrana Epirretiniana/cirurgia , Doença Iatrogênica , Complicações Intraoperatórias , Perfurações Retinianas/etiologia , Vitrectomia/efeitos adversos , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Doença Iatrogênica/epidemiologia , Incidência , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Perfurações Retinianas/epidemiologia , Fatores de Risco , Reino Unido/epidemiologia , Vitrectomia/métodos
9.
Science ; 327(5972): 1470-5, 2010 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-20299586

RESUMO

We review our understanding of Saturn's rings after nearly 6 years of observations by the Cassini spacecraft. Saturn's rings are composed mostly of water ice but also contain an undetermined reddish contaminant. The rings exhibit a range of structure across many spatial scales; some of this involves the interplay of the fluid nature and the self-gravity of innumerable orbiting centimeter- to meter-sized particles, and the effects of several peripheral and embedded moonlets, but much remains unexplained. A few aspects of ring structure change on time scales as short as days. It remains unclear whether the vigorous evolutionary processes to which the rings are subject imply a much younger age than that of the solar system. Processes on view at Saturn have parallels in circumstellar disks.


Assuntos
Gelo , Saturno , Evolução Planetária , Astronave , Água
10.
Aliment Pharmacol Ther ; 29(5): 552-60, 2009 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-19076934

RESUMO

BACKGROUND: Acute physical stress causes alteration in gut autonomic function and visceral hypersensitivity in patients with irritable bowel syndrome (IBS). We have developed a model to measure this stress response. AIM: To assess whether treatment with a drug effective in treating IBS (amitriptyline) alters the response to acute stress in IBS patients. METHODS: Nineteen patients with IBS were given amitriptyline 25-50 mg. Patients underwent physical stress (cold pressor) test at baseline and after 3 months of treatment. Physiological parameters measured were: stress perception; systemic autonomic tone [heart rate (HR) and blood pressure (BP)]; gut specific autonomic innervation [rectal mucosal blood flow (RMBF)] and visceral sensitivity (rectal electrosensitivity). RESULTS: Fourteen of 19 (74%) patients improved symptomatically after 3 months of amitriptyline. Acute stress induced increased perception of stress and systemic autonomic tone and reduced RMBF in symptomatic responders and nonresponders (P > 0.05 for all). All nonresponders but only 3 of 14 responders continued to exhibit stress-induced reduced pain threshold at 3 months (change from baseline -31% vs. +2%, P < 0.03 respectively). CONCLUSION: In this open study, amitriptyline appears to decrease stress-induced electrical hypersensitivity; this effect is independent of autonomic tone. The gut response to acute stress deserves further study as a model to study drug efficacy in IBS.


Assuntos
Amitriptilina/uso terapêutico , Analgésicos não Narcóticos/uso terapêutico , Hipersensibilidade/tratamento farmacológico , Síndrome do Intestino Irritável/tratamento farmacológico , Reto/efeitos dos fármacos , Vísceras/efeitos dos fármacos , Adulto , Feminino , Humanos , Hipersensibilidade/fisiopatologia , Síndrome do Intestino Irritável/fisiopatologia , Masculino , Pessoa de Meia-Idade , Medição da Dor , Limiar da Dor/efeitos dos fármacos , Limiar da Dor/fisiologia , Reto/fisiopatologia , Estatística como Assunto , Vísceras/fisiopatologia , Adulto Jovem
11.
Aliment Pharmacol Ther ; 25(6): 693-702, 2007 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-17311602

RESUMO

BACKGROUND: Constipation, diminished gut blood flow, ischaemic colitis and drug therapy may be associated. AIM: To study the effect of constipating medication on, and the regulation of, gut blood flow. METHODS: 24 healthy females (mean age 30) received, in a double-blind, three-way crossover study: (i) placebo, (ii) ipratropium 40 microg by inhalation (positive control known to reduce rectal mucosal blood flow) and (iii) oral loperamide 4 mg. Mucosal blood flow was measured at the splenic flexure and rectum using laser Doppler flowmetry. Blood flow in the superior and inferior mesenteric arteries was measured by trans-abdominal Doppler ultrasound. RESULTS: Ipratropium decreased rectal mucosal blood flow by 16% (P=0.009) and splenic flexure mucosal blood flow by 8% (P=0.075). Loperamide caused no change in rectal (P=0.40) or splenic flexure mucosal blood flow (P=0.73). Neither treatment changed superior or inferior mesenteric artery blood flow. Splenic flexure mucosal blood flow showed a positive correlation with rectal mucosal blood flow (r=0.69; P<0.0001). CONCLUSIONS: Vasoactive agents may reduce gut mucosal blood flow in the absence of reduced large vessel flow. Constipating drugs do not necessarily reduce gut blood flow. Rectal mucosal blood flow correlates with splenic flexure mucosal flow, and potentially may be used as a more convenient surrogate for studying splenic flexure blood flow.


Assuntos
Colo Transverso/irrigação sanguínea , Ipratrópio/farmacologia , Loperamida/farmacologia , Reto/irrigação sanguínea , Circulação Esplâncnica/efeitos dos fármacos , Administração por Inalação , Administração Oral , Adulto , Constipação Intestinal/tratamento farmacológico , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Mucosa Intestinal/irrigação sanguínea , Fluxometria por Laser-Doppler , Artéria Mesentérica Inferior/efeitos dos fármacos , Artéria Mesentérica Superior/efeitos dos fármacos , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional
12.
Neurogastroenterol Motil ; 18(12): 1112-20, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17109695

RESUMO

Ghrelin has been shown to decrease firing of gastric vagal afferents at doses comparable with circulating levels in the fasted state. This raises the possibility that ghrelin may have a hormonal action on other vagal afferent populations. The aim of this study was to determine the effects of ghrelin on jejunal afferent activity; including responses to distension, 2-methyl-5-hydroxytryptamine (2-methyl-5-HT) and cholecystokinin (CCK) in both naïve and vagotomized rats. Ghrelin significantly augmented the afferent response to distension. No effect was observed on baseline afferent discharge, or the response to 2-methyl-5-HT and CCK. The effect of ghrelin was more pronounced at lower ramp distending pressures (0-30 mmHg). Similarly, ghrelin augmented the jejunal afferent responses to phasic distension at 10-30 mmHg, but had no effect at higher pressures. Chronic subdiaphragmatic vagotomy and administration of the growth hormone secretagogue receptor (GHS-R) antagonist [D-Lys3]-GHRP-6 prevented the augmentation of the afferent responses to distension indicating ghrelin is acting through the GHS-R on vagal afferent fibres. Ghrelin augments the mechanosensation of jejunal vagal afferents and hence may lead to increased perception of hunger contractions.


Assuntos
Jejuno/inervação , Jejuno/fisiologia , Hormônios Peptídicos/farmacologia , Hormônios Peptídicos/fisiologia , Fibras Aferentes Viscerais/efeitos dos fármacos , Fibras Aferentes Viscerais/fisiologia , Animais , Cateterismo , Colagogos e Coleréticos/farmacologia , Colecistocinina/farmacologia , Complacência (Medida de Distensibilidade) , Eletrofisiologia , Grelina , Fome/fisiologia , Técnicas In Vitro , Mecanorreceptores/efeitos dos fármacos , Mecanorreceptores/fisiologia , Oligopeptídeos/farmacologia , Ratos , Ratos Sprague-Dawley , Serotonina/análogos & derivados , Serotonina/farmacologia , Cloreto de Sódio/farmacologia , Vagotomia
13.
Science ; 311(5766): 1393-401, 2006 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-16527964

RESUMO

Cassini has identified a geologically active province at the south pole of Saturn's moon Enceladus. In images acquired by the Imaging Science Subsystem (ISS), this region is circumscribed by a chain of folded ridges and troughs at approximately 55 degrees S latitude. The terrain southward of this boundary is distinguished by its albedo and color contrasts, elevated temperatures, extreme geologic youth, and narrow tectonic rifts that exhibit coarse-grained ice and coincide with the hottest temperatures measured in the region. Jets of fine icy particles that supply Saturn's E ring emanate from this province, carried aloft by water vapor probably venting from subsurface reservoirs of liquid water. The shape of Enceladus suggests a possible intense heating epoch in the past by capture into a 1:4 secondary spin/orbit resonance.


Assuntos
Saturno , Meio Ambiente Extraterreno/química , Astronave , Análise Espectral
14.
Gut ; 54(12): 1693-8, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16085693

RESUMO

BACKGROUND: Diabetic gastroparesis is a disabling condition with no consistently effective treatment. In animals, ghrelin increases gastric emptying and reverses postoperative ileus. We present the results of a double blind, placebo controlled, crossover study of ghrelin in gastric emptying in patients with diabetic gastroparesis. METHODS: Ten insulin requiring diabetic patients (five men, six type I) referred with symptoms indicative of gastroparesis received a two hour infusion of either ghrelin (5 pmol/kg/min) or saline on two occasions. Blood glucose was controlled by euglycaemic clamp. Gastric emptying rate (GER) was calculated by real time ultrasound following a test meal. Blood was sampled for ghrelin, growth hormone (GH), and pancreatic polypeptide (PP) levels. Cardiovagal neuropathy was assessed using the Mayo Clinic composite autonomic severity score (range 0 (normal)-3). RESULTS: Baseline ghrelin levels were mean 445 (SEM 36) pmol/l. Ghrelin infusion achieved a peak plasma level of 2786 (188) pmol/l at 90 minutes, corresponding to a peak GH of 70.9 (19.8) pmol/l. Ghrelin increased gastric emptying in seven of 10 patients (30 (6)% to 43 (5)%; p = 0.04). Impaired cardiovagal tone correlated inversely with peak postprandial PP values (p < 0.05) but did not correlate with GER. CONCLUSIONS: Ghrelin increases gastric emptying in patients with diabetic gastroparesis. This is independent of vagal tone. We propose that analogues of ghrelin may represent a new class of prokinetic agents.


Assuntos
Complicações do Diabetes/tratamento farmacológico , Esvaziamento Gástrico/efeitos dos fármacos , Gastroparesia/tratamento farmacológico , Hormônios Peptídicos/uso terapêutico , Adulto , Estudos Cross-Over , Complicações do Diabetes/diagnóstico por imagem , Complicações do Diabetes/fisiopatologia , Método Duplo-Cego , Esquema de Medicação , Feminino , Gastroparesia/diagnóstico por imagem , Gastroparesia/fisiopatologia , Grelina , Humanos , Masculino , Pessoa de Meia-Idade , Hormônios Peptídicos/sangue , Estômago/diagnóstico por imagem , Ultrassonografia
15.
Science ; 307(5713): 1226-36, 2005 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-15731439

RESUMO

Images acquired of Saturn's rings and small moons by the Cassini Imaging Science Subsystem (ISS) during the first 9 months of Cassini operations at Saturn have produced many new findings. These include new saturnian moons; refined orbits of new and previously known moons; narrow diffuse rings in the F-ring region and embedded in gaps within the main rings; exceptionally fine-scale ring structure in moderate- to high-optical depth regions; new estimates for the masses of ring-region moons, as well as ring particle properties in the Cassini division, derived from the analysis of linear density waves; ring particle albedos in select ring regions; and never-before-seen phenomena within the rings.

16.
Science ; 307(5713): 1237-42, 2005 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-15731440

RESUMO

The Cassini Imaging Science Subsystem acquired high-resolution imaging data on the outer Saturnian moon, Phoebe, during Cassini's close flyby on 11 June 2004 and on Iapetus during a flyby on 31 December 2004. Phoebe has a heavily cratered and ancient surface, shows evidence of ice near the surface, has distinct layering of different materials, and has a mean density that is indicative of an ice-rock mixture. Iapetus's dark leading side (Cassini Regio) is ancient, heavily cratered terrain bisected by an equatorial ridge system that reaches 20 kilometers relief. Local albedo variations within and bordering Cassini Regio suggest mass wasting of ballistically deposited material, the origin of which remains unknown.


Assuntos
Saturno , Meio Ambiente Extraterreno , Sedimentos Geológicos , Gelo , Astronave , Água
17.
Science ; 307(5713): 1243-7, 2005 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-15731441

RESUMO

The Cassini Imaging Science Subsystem (ISS) began observing Saturn in early February 2004. From analysis of cloud motions through early October 2004, we report vertical wind shear in Saturn's equatorial jet and a maximum wind speed of approximately 375 meters per second, a value that differs from both Hubble Space Telescope and Voyager values. We also report a particularly active narrow southern mid-latitude region in which dark ovals are observed both to merge with each other and to arise from the eruptions of large, bright storms. Bright storm eruptions are correlated with Saturn's electrostatic discharges, which are thought to originate from lightning.


Assuntos
Saturno , Atmosfera , Meio Ambiente Extraterreno , Astronave , Vento
18.
Disabil Rehabil ; 26(16): 963-73, 2004 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-15371044

RESUMO

PURPOSE: To gain an understanding of the embodied perceptual experience of successful prosthesis. METHOD: The data for this study were transcripts derived from in-depth semi-structured e-mail (n=21) and face-to-face (n=14) interviews, and the documentary analysis of an e-mail discussion group for prosthesis users. This qualitative data was subject to an Interpretative Phenomenological Analysis. RESULTS: Analysis of the research data identified six themes in the perceptually embodied experiences of prosthesis users: Adjusting to a prosthetic; The Balance of the Body; Awareness of the Prosthesis; The Knowing Body; The Phantom Becomes the Prosthesis: Extending the Body; and The Prosthesis as Tool or Corporeal Structure. CONCLUSION: The often-cited reasons for the rejection of prostheses are frequently part of the initial experiences of 'successful' prosthesis users also. This suggests the need to sufficiently motivate potential prosthesis users in the period between an experience of prosthesis use as unnatural and wieldy to one of pre-reflective, natural use. In addition, two broad forms of prosthesis experience were identified: one in which the prosthesis was experienced as a corporeal structure; and one in which it was viewed as a tool. While future work may be able to explore the psychosocial correlates of these experiences, it is nonetheless the case that persons with these differing experiences were able to enjoy the benefits imbued by prosthesis use.


Assuntos
Adaptação Psicológica , Membros Artificiais/psicologia , Imagem Corporal , Adolescente , Adulto , Idoso , Conscientização , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Membro Fantasma/psicologia , Equilíbrio Postural , Reino Unido
19.
Disabil Rehabil ; 26(13): 808-16, 2004 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-15371053

RESUMO

PURPOSE: To investigate the meaning and experience of being a stroke survivor. METHOD: Qualitative in-depth semi-structured interviews were conducted with 10 stroke survivors (five face-to-face and five e-mail interviews). The interview data were transcribed verbatim (these were pre-transcribed in e-mail exchange) and analysed using Interpretative Phenomenological Analysis. RESULTS: Four themes emerged from the analysis: Disrupted embodiment and the loss of self; Invisibility of emotional difficulties; Gender, romance and sexuality; and Social interaction. These themes, respectively, revealed that participants often had difficulties with psychological adaptation to the physically disabling aspects of their stroke; they experienced enduring and disabling emotional difficulties; they had a particular concern for the viability and maintenance of romantic and sexual relationships; and they often became socially withdrawn, resulting in an increased pressure on familial caregivers. CONCLUSION: The findings of the present work suggest the need for post-stroke counselling regarding romantic and sexual relationships, as well as promoting acceptance of some of the physical disabilities that come with having a stroke and encouraging positive self-regard. There would also appear to be a need to address the issue of social withdrawal and familial relationships, perhaps when health professionals convey information regarding the person's stroke, and in counselling targeted specifically at family caregivers.


Assuntos
Acidente Vascular Cerebral/psicologia , Sobreviventes/psicologia , Adaptação Psicológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Relações Interpessoais , Entrevistas como Assunto , Masculino , Homens/psicologia , Pessoa de Meia-Idade , Sexualidade/psicologia , Isolamento Social , Mulheres/psicologia
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