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RATIONALE: Understanding and manipulating the cardiomyocyte cell cycle has been the focus of decades of research, however the ultimate goal of activating mitotic activity in adult mammalian cardiomyocytes remains elusive and controversial. The relentless pursuit of controlling cardiomyocyte mitosis has been complicated and obfuscated by a multitude of indices used as evidence of cardiomyocyte cell cycle activity that lack clear identification of cardiomyocyte "proliferation" versus cell cycle progression, endoreplication, endomitosis, and even DNA damage. Unambiguous appreciation of the complexity of cardiomyocyte replication that avoids oversimplification and misinterpretation is desperately needed. OBJECTIVE: Track cardiomyocyte cell cycle activity and authenticate fidelity of proliferation markers as indicators of de novo cardiomyogenesis in post-mitotic cardiomyocytes. METHODS AND RESULTS: Cardiomyocytes expressing the FUCCI construct driven by the α-myosin heavy chain promoter were readily and uniformly detected through the myocardium of transgenic mice. Cardiomyocyte cell cycle activity peaks at postnatal day 2 and rapidly declines thereafter with almost all cardiomyocytes arrested at the G1/S cell cycle transition. Myocardial infarction injury in adult hearts prompts transient small increases in myocytes progressing through cell cycle without concurrent mitotic activity, indicating lack of cardiomyogenesis. In comparison, cardiomyogenic activity during early postnatal development correlated with coincidence of FUCCI and cKit+ cells that were undetectable in the adult myocardium. CONCLUSIONS: Cardiomyocyte-specific expression of Fluorescence Ubiquitination-based Cell Cycle Indicators (FUCCI) reveals previously unappreciated aspects of cardiomyocyte cell cycle arrest and biological activity in postnatal development and in response to pathologic damage. Compared to many other methods and model systems, the FUCCI transgenic (FUCCI-Tg) mouse represents a valuable tool to unambiguously track cell cycle and proliferation of the entire cardiomyocyte population in the adult murine heart. FUCCI-Tg provides a desperately needed novel approach in the armamentarium of tools to validate cardiomyocyte proliferative activity that will reveal cell cycle progression, discriminate between cycle progression, DNA replication, and proliferation, and provide important insight for enhancing cardiomyocyte proliferation in the context of adult myocardial tissue.
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Ciclo Celular , Técnicas de Transferência de Genes , Coração/fisiologia , Miócitos Cardíacos/citologia , Ubiquitinação , Animais , Animais Recém-Nascidos , Pontos de Checagem do Ciclo Celular , Divisão Celular , Proliferação de Células , Células Cultivadas , Fluorescência , Camundongos Transgênicos , Especificidade de ÓrgãosRESUMO
OBJECTIVE: Although meningioma patients show deficits in objective cognitive functioning (OCF) measured with neuropsychological tests, subjective cognitive functioning (SCF) has received little attention. We investigate SCF from pre- to postsurgery and its associations with OCF, psychological, sociodemographic, and clinical characteristics. METHODS: SCF was measured using the Cognitive Failures Questionnaire (CFQ) 1 day before (T0) and 3 (T3) and 12 months (T12) after surgery. Patients' scores were compared with normative data and changes over time were assessed. The neuropsychological battery CNS Vital Signs and the Hospital Anxiety and Depression Scale were administered. Correlations of SCF with OCF, psychological, sociodemographic, and clinical characteristics were explored. RESULTS: Patients reported significantly better SCF as compared with controls at T0 (N = 54) and T3 (N = 242), but not at T12 (N = 50). A significant decrease in group level SCF was observed from T0 to T12 (n = 24, P < .001). SCF was associated with anxiety at all time points (rs = -0.543 to -0.352) and with depression at T3 and T12 (r = -0.338 and -0.574), but not with OCF, sociodemographic, or clinical characteristics (rs = -0.202 to 0.288). CONCLUSIONS: Meningioma patients experienced better SCF as compared with controls before and 3 months after surgery, which might be the result of phenomena related to disease and recovery. As the findings suggest that cognitive symptoms might increase later on, future studies should further investigate the course of SCF in meningioma patients. In clinical practice, measurements of SCF should be combined with those of OCF and psychological distress in order to determine whether and which interventions are needed.
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Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/psicologia , Neoplasias Meníngeas/psicologia , Neoplasias Meníngeas/cirurgia , Meningioma/psicologia , Meningioma/cirurgia , Medidas de Resultados Relatados pelo Paciente , Adulto , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/etiologia , Autoavaliação Diagnóstica , Feminino , Seguimentos , Humanos , Masculino , Neoplasias Meníngeas/complicações , Meningioma/complicações , Pessoa de Meia-Idade , Testes Neuropsicológicos , Adulto JovemRESUMO
INTRODUCTION: Many patients with brain cancer experience cognitive problems. In this narrative review, we comprehensively evaluated empirical studies on various intervention approaches for cognitive problems in these patients. METHODS: Intervention studies that reported effects on cognitive functioning (either objectively tested or subjectively reported) in adult patients with primary and/or secondary brain tumours were identified through online searches in PubMed (MEDLINE) and Web of Science up to 13 March 2019. RESULTS: Of the 364 identified records, 10 pharmacological (including five randomised placebo-controlled trials), 10 cognitive rehabilitation (including five [pilot] RCTs) and two multiple-group exercise studies matched the inclusion criteria. Seventeen of 22 studies had final sample sizes smaller than 40. Several cognitive rehabilitation studies and some pharmacological approaches (donepezil and memantine) showed (at least partial) benefits for cognitive problems in adults with brain cancer. The effects of other pharmacological and exercise interventions were inconclusive and/or preliminary. CONCLUSION: Overall, drawing firm conclusions is complicated due to various methodological shortcomings, including the absence of a (placebo) control group and small sample sizes. Promising effects have been reported for cognitive rehabilitation and some pharmacological approaches. Suggestions for more thorough research with respect to the various approaches are provided.
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Neoplasias Encefálicas/reabilitação , Estimulantes do Sistema Nervoso Central/uso terapêutico , Inibidores da Colinesterase/uso terapêutico , Disfunção Cognitiva/reabilitação , Remediação Cognitiva , Dopaminérgicos/uso terapêutico , Exercício Físico , Neoplasias Encefálicas/psicologia , Cognição , Disfunção Cognitiva/psicologia , Donepezila/uso terapêutico , Ginkgo biloba , Humanos , Memantina/uso terapêutico , Extratos Vegetais/uso terapêuticoRESUMO
Electronic defect states at material interfaces provide highly deleterious sources of noise in solid-state nanostructures, and even a single trapped charge can qualitatively alter the properties of short one-dimensional nanowire field-effect transistors (FET) and quantum bit (qubit) devices. Understanding the dynamics of trapped charge is thus essential for future nanotechnologies, but their direct detection and manipulation is rather challenging. Here, a transistor-based set-up is used to create and probe individual electronic defect states that can be coherently driven with microwave (MW) pulses. Strikingly, we resolve a large number of very high quality (Q â¼ 1 × 105) resonances in the transistor current as a function of MW frequency and demonstrate both long decoherence times (â¼1 µs-40 µs) and coherent control of the defect-induced dynamics. Efficiently characterizing over 800 individually addressable resonances across two separate defect-hosting materials, we propose that their properties are consistent with weakly driven two-level systems.
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The Cassini spacecraft orbiting Saturn carries the composite infrared spectrometer (CIRS) designed to study thermal emission from Saturn and its rings and moons. CIRS, a Fourier transform spectrometer, is an indispensable part of the payload providing unique measurements and important synergies with the other instruments. It takes full advantage of Cassini's 13-year-long mission and surpasses the capabilities of previous spectrometers on Voyager 1 and 2. The instrument, consisting of two interferometers sharing a telescope and a scan mechanism, covers over a factor of 100 in wavelength in the mid and far infrared. It is used to study temperature, composition, structure, and dynamics of the atmospheres of Jupiter, Saturn, and Titan, the rings of Saturn, and surfaces of the icy moons. CIRS has returned a large volume of scientific results, the culmination of over 30 years of instrument development, operation, data calibration, and analysis. As Cassini and CIRS reach the end of their mission in 2017, we expect that archived spectra will be used by scientists for many years to come.
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This publisher's note renumbers the reference list in Appl. Opt.56, 5274 (2017)APOPAI0003-693510.1364/AO.56.005274.
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Introduction: eHealth seems promising in addressing challenges in the provision of care for Huntington's disease (HD) across Europe. By harnessing information and communication technologies, eHealth can partially relocate care from specialized centers to the patients' home, thereby increasing the availability and accessibility of specialty care services beyond regional borders. Previous research on eHealth (development) in HD is however limited, especially when it comes to including eHealth services specifically designed together with HD gene expansion carriers (HDGECs) and their partners to fit their needs and expectations. Methods: This article describes the qualitative human-centered design process and first evaluations of the Huntington Support App prototype: a web-app aimed to support the quality of life (QoL) of HDGECs and their partners in Europe. Prospective end-users, i.e., HDGECs, their partners, and healthcare providers (HCPs), from different countries were involved throughout the development process. Through interviews, we captured people's experiences with the disease, quality of life (QoL), and eHealth. We translated their stories into design directions that were further co-designed and subsequently evaluated with the user groups. Results: The resulting prototype centralizes clear and reliable information on the disease, HD-related news and events, as well as direct contact possibilities with HCPs via an online walk-in hour or by scheduling an appointment. The app's prototype was positively received and rated as (very) appealing, pleasant, easy to use and helpful by both HDGECs and partners. Discussion: By involving end-users in every step, we developed a healthcare app that meets relevant needs of individuals affected by HD and therefore may lead to high adoption and retention rates. As a result, the app provides low-threshold access to reliable information and specialized care for HD in Europe. A description of the Huntington Support App as well as implications for further development of the app's prototype are provided.
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BACKGROUND: The Simulated Colonoscopy Objective Performance Evaluation (SCOPE) was developed to fill the need for a lower-cost, non-virtual-reality (VR)-based assessment tool. This study aimed to evaluate the ability of SCOPE to assess endoscopic skills objectively. METHODS: Four tasks were created using the Kyoto Kagaku colonoscopy model (Kyoto Kagaku Co., Ltd., Kyoto, Japan). The SCOPE tasks included Scope Manipulation (SM) requiring torque and tip deflection to align a shape in the colon with a matching shape on the monitor; Tool Targeting (TT) requiring coordination with biopsy forceps to contact a metal target; Loop Management (LM) requiring prevention, recognition, and reduction of a redundant sigmoid colon with navigation to the cecum; and Mucosal Inspection (MI) requiring identification of simulated polyps during withdrawal and retroflexion. Key performance metrics were identified, and a normalized scoring system was developed. For the study, 35 subjects were stratified into three cohorts based on colonoscopy experience: novice (0-50 colonoscopies; n = 11), intermediate (51-139 colonoscopies; n = 13), and experienced (>140 colonoscopies; n = 11). The subjects performed two trials of all four tasks. RESULTS: Across all four tasks, the experienced endoscopists (E) consistently outperformed the intermediates (I), who in turn outperformed the novices (N). The mean normalized scores with 95 % confidence intervals (CI) are as follows: SM: N (54; range, 26-82), I (92; range, 79-106), E (106; range, 93-118) (p = 0.0006). TT: N (40; range, 24-55), I (77; range, 63-91), E (88; range, 72-105) (p < 0.0001). LM: N (51; range, 24-79), I (80; range, 59-101), E (101; range, 98-105) (p = 0.003). MI: N (73; range, 53-92), I (85; range, 76-95), E (100; range, 91-108) (p = 0.013). Total score: N (218; range, 155-280), I (335; range, 299-371), E (395; range, 371-419) (p < 0.0001). The test-retest reliability (0.6) for the expert total score was respectable. CONCLUSIONS: The validity evidence from this study shows that scores on SCOPE tasks can differentiate between groups expected to have different levels of technical skill. This model shows promise as a low-technology tool for objective assessment or training of endoscopic skills.
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Competência Clínica , Colonoscopia/educação , Avaliação Educacional/economia , Avaliação Educacional/métodos , Modelos Educacionais , Controle de Custos , Feminino , Humanos , Japão , Reprodutibilidade dos Testes , Análise e Desempenho de TarefasRESUMO
BACKGROUND: Huntington's disease (HD) is a genetic, neurodegenerative disease. Due to the progressive nature of HD and the absence of a cure, (health-related) quality of life ((HR)QoL) is an important topic. Several studies have investigated (HR)QoL in HD, yet a clear synthesis of the existing literature is lacking to date. We performed a systematic review on self-reported (HR)QoL, and factors and intervention effects associated with (HR)QoL in premanifest and manifest HD gene expansion carriers (pHDGECs and mHDGECs, respectively). METHODS: PubMed, EMBASE, Web of Science, and PsycINFO were searched systematically from September 17th, 2021, up to August 11th, 2022. Methodological and conceptual quality of the included studies was assessed with two appraisal tools. RESULTS: 30 out of 70 eligible articles were included. mHDGECs experienced lower (HR)QoL compared to pHDGECs and controls, whereas mixed findings were reported when compared to other neurological diseases. Several factors were associated with (HR)QoL that might contribute to lower (HR)QoL in mHDGECs, including depressive symptoms, physical and psychological symptoms, lower functional capacity, lower support, and unmet needs. Multidisciplinary rehabilitation programs and a respiratory muscle training were beneficial for (HR)QoL in mHDGECs. DISCUSSION: (HR)QoL is experienced differently across the course of the disease. Although (HR)QoL is key for understanding the impact of HD and the effect of symptomatic treatment, there is a need to improve the methodological and conceptual shortcomings that were found in most studies, especially regarding the conceptual clarity when reporting on QoL and HRQoL. Suggestions for strengthening these shortcomings are provided in this review.
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Doença de Huntington , Doenças Neurodegenerativas , Humanos , Qualidade de Vida/psicologia , Doenças Neurodegenerativas/complicações , AutorrelatoRESUMO
Background: Huntington's disease (HD) is an autosomal dominant neurodegenerative disease that affects the quality of life (QoL) of HD gene expansion carriers (HDGECs) and their partners. Although HD expertise centers have been emerging across Europe, there are still some important barriers to care provision for those affected by this rare disease, including transportation costs, geographic distance of centers, and availability/accessibility of these services in general. eHealth seems promising in overcoming these barriers, yet research on eHealth in HD is limited and fails to use telehealth services specifically designed to fit the perspectives and expectations of HDGECs and their families. In the European HD-eHelp study, we aim to capture the needs and wishes of HDGECs, partners of HDGECs, and health care providers (HCPs) in order to develop a multinational eHealth platform targeting QoL of both HDGECs and partners at home. Methods: We will employ a participatory user-centered design (UCD) approach, which focusses on an in-depth understanding of the end-users' needs and their contexts. Premanifest and manifest adult HDGECs (n = 76), partners of HDGECs (n = 76), and HCPs (n = 76) will be involved as end-users in all three phases of the research and design process: (1) Exploration and mapping of the end-users' needs, experiences and wishes; (2) Development of concepts in collaboration with end-users to ensure desirability; (3) Detailing of final prototype with quick review rounds by end-users to create a positive user-experience. This study will be conducted in the Netherlands, Germany, Czech Republic, Italy, and Ireland to develop and test a multilingual platform that is suitable in different healthcare systems and cultural contexts. Discussion: Following the principles of UCD, an innovative European eHealth platform will be developed that addresses the needs and wishes of HDGECs, partners and HCPs. This allows for high-quality, tailored care to be moved partially into the participants' home, thereby circumventing some barriers in current HD care provision. By actively involving end-users in all design decisions, the platform will be tailored to the end-users' unique requirements, which can be considered pivotal in eHealth services for a disease as complex and rare as HD.
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AIMS: Telomere attrition in cardiomyocytes is associated with decreased contractility, cellular senescence, and up-regulation of proapoptotic transcription factors. Pim1 is a cardioprotective kinase that antagonizes the aging phenotype of cardiomyocytes and delays cellular senescence by maintaining telomere length, but the mechanism remains unknown. Another pathway responsible for regulating telomere length is the transforming growth factor beta (TGFß) signalling pathway where inhibiting TGFß signalling maintains telomere length. The relationship between Pim1 and TGFß has not been explored. This study delineates the mechanism of telomere length regulation by the interplay between Pim1 and components of TGFß signalling pathways in proliferating A549 cells and post-mitotic cardiomyocytes. METHODS AND RESULTS: Telomere length was maintained by lentiviral-mediated overexpression of PIM1 and inhibition of TGFß signalling in A549 cells. Telomere length maintenance was further demonstrated in isolated cardiomyocytes from mice with cardiac-specific overexpression of PIM1 and by pharmacological inhibition of TGFß signalling. Mechanistically, Pim1 inhibited phosphorylation of Smad2, preventing its translocation into the nucleus and repressing expression of TGFß pathway genes. CONCLUSION: Pim1 maintains telomere lengths in cardiomyocytes by inhibiting phosphorylation of the TGFß pathway downstream effectors Smad2 and Smad3, which prevents repression of telomerase reverse transcriptase. Findings from this study demonstrate a novel mechanism of telomere length maintenance and provide a potential target for preserving cardiac function.
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Senescência Celular/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Homeostase do Telômero/efeitos dos fármacos , Fator de Crescimento Transformador beta1/farmacologia , Células A549 , Animais , Humanos , Masculino , Camundongos Knockout , Miócitos Cardíacos/enzimologia , Fosforilação , Proteínas Proto-Oncogênicas c-pim-1/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transdução de Sinais , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Telomerase/metabolismoRESUMO
Two recent reports have highlighted ANK3 as a susceptibility gene for bipolar disorder (BD). We first reported association between BD and the ANK3 marker rs9804190 in a genome-wide association study (GWAS) of two independent samples (Baum et al., 2008). Subsequently, a meta-analysis of GWAS data based on samples from the US and the UK reported association with a different ANK3 marker, rs10994336 (Ferreira et al., 2008). The markers lie about 340 kb apart in the gene. Here, we test both markers in additional samples and characterize the contribution of each marker to BD risk. Our previously reported findings at rs9804190, which had been based on DNA pooling, were confirmed by individual genotyping in the National Institute of Mental Health (NIMH) waves 1-4 (P=0.05; odds ratio (OR)=1.24) and German (P=0.0006; OR=1.34) samples. This association was replicated in an independent US sample known as NIMH wave 5 (466 cases, 212 controls; P=0.017; OR=1.38). A random-effects meta-analysis of all three samples was significant (P=3 x 10(-6); OR=1.32), with no heterogeneity. Individual genotyping of rs10994336 revealed a significant association in the German sample (P=0.0001; OR=1.70), and similar ORs in the NIMH 1-4 and NIMH 5 samples that were not significant at the P<0.05 level. Meta-analysis of all three samples supported an association with rs10994336 (P=1.7 x 10(-5); OR=1.54), again with no heterogeneity. There was little linkage disequilibrium between the two markers. Further analysis suggested that each marker contributed independently to BD, with no significant marker x marker interaction. Our findings strongly support ANK3 as a BD susceptibility gene and suggest true allelic heterogeneity.
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Anquirinas/genética , Transtorno Bipolar/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único/genética , Adulto , Estudos de Casos e Controles , Feminino , Frequência do Gene , Estudo de Associação Genômica Ampla/métodos , Genótipo , Alemanha , Humanos , Desequilíbrio de Ligação , Masculino , Metanálise como Assunto , Pessoa de Meia-Idade , National Institute of Mental Health (U.S.) , Fatores de Risco , Estados Unidos , Adulto JovemRESUMO
The Earth's equatorial stratosphere shows oscillations in which the east-west winds reverse direction and the temperatures change cyclically with a period of about two years. This phenomenon, called the quasi-biennial oscillation, also affects the dynamics of the mid- and high-latitude stratosphere and weather in the lower atmosphere. Ground-based observations have suggested that similar temperature oscillations (with a 4-5-yr cycle) occur on Jupiter, but these data suffer from poor vertical resolution and Jupiter's stratospheric wind velocities have not yet been determined. Here we report maps of temperatures and winds with high spatial resolution, obtained from spacecraft measurements of infrared spectra of Jupiter's stratosphere. We find an intense, high-altitude equatorial jet with a speed of approximately 140 m s(-1), whose spatial structure resembles that of a quasi-quadrennial oscillation. Wave activity in the stratosphere also appears analogous to that occurring on Earth. A strong interaction between Jupiter and its plasma environment produces hot spots in its upper atmosphere and stratosphere near its poles, and the temperature maps define the penetration of the hot spots into the stratosphere.
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Spectral features observed with the Mariner 9 interferometer spectrometer are identified as those of H(2)O ice. The measured spectra are compared with theoretical calculations for the transfer of radiation through clouds of ice particles with variations in size distribution and integrated cloud mass. Comparisons with an observed spectrum from the Tharsis Ridge region indicate H(2)O ice clouds composed of particles with a mean radius of 2.0 micrometers and an integrated cloud mass of 5 x 10(-5) grain per square centimeter.
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The Mariner 9 infrared spectroscopy experiment has provided goodquality spectra of many areas of Mars, predominantly in the southern hemisphere. Large portions of the thermal emission spectra are significantly affected by dust with a silicon oxide content approximately corresponding to that of an intermediate igneous rock, thus implying that Mars has undergone substantial geochemical differentiation. Derived temperature profiles indicate a warm daytime upper atmosphere with a strong warming over the south polar cap. Atmospheric water vapor is clearly observed over the south polar area and less strongly over other regions.
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Infrared spectra obtainedfrom Voyager 2 have provided additional data on the Jovian system, complementing those obtained from Voyager 1. The abundance ratio of ethane to acetylene in Jupiter's atmosphere appears to be about three times larger in the polar regions than at lower latitudes. A decidedly hemispherical asymmetry exists, with somewhat higher ratios prevailing in northern latitudes. An overall increase in the abundance ratio by a factor of about 1.7 appears to have occurred between the Voyager 1 and 2 encounters. Global brightness temperature maps of Jupiter at 226 and 602 cm(-1) exhibit a large amount of local- and planetary-scale structure, as well as temporal variability. Although heterogeneous cloud structure and ammonia concentration in the lower troposphere may contribute to the appearance of the 226-cm(-1) map, the detail in the 602-cm(-1) maps probably represents the actual horizontal thermal structure near the tropopause and suggests that dynamical heating and cooling processes are important. Low-latitude surface temperatures on the Galilean satellites rangefrom approximately 80 K on the dark sides to 155 K at the subsolar point on Callisto. Below a thin insulating layer, the thermal inertia of Callisto is somewhat greater than that of Earth's moon. Upper limits on the infrared optical depth of the Jovian ring rangingfrom approximately 3 x 10(-4) at 250 cm(-1) to 3 x 10(-3) at 600 cm(-1) have been found.
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The infrared spectroscopy and radiometry investigation has obtained spectra of Jupiter and its satellites between approximately 180 and 2500 cm(-1) with a spectral resolution of 4.3 cm(-1). The Jupiter spectra show clear evidence of H(2), CH(4) C(2)H(2), C(2)H(6), CH(3)D, NH(3), PH(3), H(2)O, and GeH(4). A helium concentration of 0.11 +/- 0.03 by volume is obtained. Meridional temperature cross sections show considerable structure. At high latitudes, the stratosphere is warmer in the north than in the south. The upper troposphere and lower stratosphere are locally cold over the Great Red Spot. Amalthea is warmer than expected. Considerable thermal structure is observed on Io, including a relatively hot region in the vicinity of a volcanic feature.
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The infrared interferometer spectrometer (IRIS) on Voyager 2 recorded thermal emission spectra of Uranus between 200 and 400 cm(-1) and of Miranda and Ariel between 200 and 500 cm(-1) with a spectral resolution of 4.3 cm(-1). Reflected solar radiation was also measured with a single-channel radiometer sensitive in the visible and near infrared. By combining IRIS spectra with radio science results, a mole fraction for atmospheric helium of 0.15 +/- 0.05 (mass fraction, 0.26 +/- 0.08) is found. Vertical temperature profiles between 60 and 900 millibars were derived from average polar and equatorial spectra. Temperatures averaged over a layer between 400 to 900 millibars show nearly identical values at the poles and near the equator but are 1 or 2 degrees lower at mid-latitudes in both hemispheres. The cooler zone in the southern hemisphere appears darker in reflected sunlight than the adjacent areas. An upper limit for the effective temperature of Uranus is 59.4 kelvins. Temperatures of Miranda and Ariel at the subsolar point are 86 +/- 1 and 84 +/- 1 kelvins, respectively, implying Bond albedos of 0.24 +/- 0.06 and 0.31 +/- 0.06, respectively. Estimates of phase integrals suggest that these satellites have unusual surface microstructure.
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During the passage of Voyager 2 through the Saturn system, infrared spectral and radiometric data were obtained for Saturn, Titan, Enceladus, Tethys, Iapetus, and the rings. Combined Voyager 1 and Voyager 2 observations of temperatures in the upper troposphere of Saturn indicate a seasonal asymmetry between the northern and southern hemispheres, with superposed small-scale meridional gradients. Comparison of high spatial resolution data from the two hemispheres poleward of 60 degrees latitude suggests an approximate symmetry in the small-scale structure, consistent with the extension of a symmetric system of zonal jets into the polar regions. Longitudinal variations of 1 to 2 K are observed. Disk- averaged infrared spectra of Titan show little change over the 9-month interval between Voyager encounters. By combining Voyager 2 temperature measurements with ground-based geometric albedo determinations, phase integrals of 0.91 +/- 0.13 and 0.89 +/- 0.09 were derived for Tethys and Enceladus, respectively. The subsolar point temperature of dark material on Iapetus must exceed 110 K. Temperatures (and infrared optical depths) for the A and C rings and for the Cassini division are 69 +/- 1 K (0.40 +/- 0.05), 85 +/- 1 K (0.10 +/- 0.03), and 85 +/- 2 K (0.07 +/- 0.04), respectively.