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1.
Neurourol Urodyn ; 39(2): 863-870, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31845393

RESUMEN

AIMS: Antenatal pelvic floor muscle training (PFMT) may be effective for the prevention and treatment of urinary and fecal incontinence both in pregnancy and postnatally, but it is not routinely implemented in practice despite guideline recommendations. This review synthesizes evidence that exposes challenges, opportunities, and concerns regarding the implementation of PFMT during the childbearing years, from the perspective of individuals, healthcare professionals (HCPs), and organizations. METHODS: Critical interpretive synthesis of systematically identified primary quantitative or qualitative studies or research syntheses of women's and HCPs attitudes, beliefs, or experiences of implementing PFMT. RESULTS: Fifty sources were included. These focused on experiences of postnatal urinary incontinence (UI) and perspectives of individual postnatal women, with limited evidence exploring the views of antenatal women and HCP or wider organizational and environmental issues. The concept of agency (people's ability to effect change through their interaction with other people, processes, and systems) provides an over-arching explanation of how PFMT can be implemented during childbearing years. This requires both individual and collective action of women, HCPs, maternity services and organizations, funders and policymakers. CONCLUSION: Numerous factors constrain women's and HCPs capacity to implement PFMT. It is unrealistic to expect women and HCPs to implement PFMT without reforming policy and service delivery. The implementation of PFMT during pregnancy, as recommended by antenatal care and UI management guidelines, requires policymakers, organizations, HCPs, and women to value the prevention of incontinence throughout women's lives by using low-risk, low-cost, and proven strategies as part of women's reproductive health.


Asunto(s)
Diafragma Pélvico , Modalidades de Fisioterapia , Atención Prenatal , Trastornos Puerperales/prevención & control , Incontinencia Urinaria/prevención & control , Actitud del Personal de Salud , Actitud Frente a la Salud , Atención a la Salud , Terapia por Ejercicio , Incontinencia Fecal/prevención & control , Incontinencia Fecal/terapia , Femenino , Política de Salud , Humanos , Guías de Práctica Clínica como Asunto , Embarazo , Complicaciones del Embarazo , Trastornos Puerperales/terapia , Investigación Cualitativa , Reino Unido , Incontinencia Urinaria/terapia
2.
J Autoimmun ; 77: 11-38, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27939129

RESUMEN

Campylobacter jejuni is a leading cause of bacterial gastroenteritis linked to several serious autoimmune sequelae such as the peripheral neuropathies Guillain Barré syndrome (GBS) and Miller Fisher syndrome (MFS). We hypothesized that GBS and MFS can result in NOD wild type (WT) mice or their congenic interleukin (IL)-10 or B7-2 knockouts secondary to C. jejuni infection. Mice were gavaged orally with C. jejuni strains HB93-13 and 260.94 from patients with GBS or CF93-6 from a patient with MFS and assessed for clinical neurological signs and phenotypes, anti-ganglioside antibodies, and cellular infiltrates and lesions in gut and peripheral nerve tissues. Significant increases in autoantibodies against single gangliosides (GM1, GQ1b, GD1a) occurred in infected NOD mice of all genotypes, although the isotypes varied (NOD WT had IgG1, IgG3; NOD B7-2-/- had IgG3; NOD IL-10-/- had IgG1, IgG3, IgG2a). Infected NOD WT and NOD IL-10-/- mice also produced anti-ganglioside antibodies of the IgG1 isotype directed against a mixture of GM1/GQ1b gangliosides. Phenotypic tests showed significant differences between treatment groups of all mouse genotypes. Peripheral nerve lesions with macrophage infiltrates were significantly increased in infected mice of NOD WT and IL-10-/- genotypes compared to sham-inoculated controls, while lesions with T cell infiltrates were significantly increased in infected mice of the NOD B7-2-/- genotype compared to sham-inoculated controls. In both infected and sham inoculated NOD IL-10-/- mice, antibiotic treatment exacerbated neurological signs, lesions and the amount and number of different isotypes of antiganglioside autoantibodies produced. Thus, inducible mouse models of post-C. jejuni GBS are feasible and can be characterized based on evaluation of three factors-onset of GBS clinical signs/phenotypes, anti-ganglioside autoantibodies and nerve lesions. Based on these factors we characterized 1) NOD B-7-/- mice as an acute inflammatory demyelinating polyneuropathy (AIDP)-like model, 2) NOD IL-10-/- mice as an acute motor axonal neuropathy (AMAN)-like model best employed over a limited time frame, and 3) NOD WT mice as an AMAN model with mild clinical signs and lesions. Taken together these data demonstrate that C. jejuni strain genotype, host genotype and antibiotic treatment affect GBS disease outcomes in mice and that many disease phenotypes are possible.


Asunto(s)
Antibacterianos/efectos adversos , Infecciones por Campylobacter/complicaciones , Infecciones por Campylobacter/microbiología , Campylobacter jejuni , Síndrome de Guillain-Barré/etiología , Síndrome de Guillain-Barré/patología , Animales , Antibacterianos/farmacología , Anticuerpos Antibacterianos/inmunología , Autoanticuerpos/inmunología , Infecciones por Campylobacter/tratamiento farmacológico , Citocinas/sangre , Citocinas/metabolismo , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Ganglios Espinales/inmunología , Ganglios Espinales/metabolismo , Ganglios Espinales/patología , Síndrome de Guillain-Barré/fisiopatología , Inmunoglobulina G/inmunología , Ratones , Ratones Endogámicos NOD , Ratones Noqueados , Nervios Periféricos/metabolismo , Nervios Periféricos/patología , Nervios Periféricos/fisiopatología , Nervios Periféricos/virología , Fenotipo , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo
3.
Surgeon ; 13(1): 5-8, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24461620

RESUMEN

BACKGROUND: Hip and knee arthroplasties are very common operations in the UK with over 150,000 hip and knee arthroplasties taking place in England and Wales in 2011. Fortunately mortality following these operations is rare. This study aimed to evaluate the incidence and causes of death within 30 days after undergoing hip or knee arthroplasty in our unit and to highlight possible risk factors. METHODS: We looked at 30-day mortality in all patients undergoing hip or knee arthroplasty in our institution between 2005 and 2011. Data on post-operative deaths was requested from the Information Services Division (ISD) and correlated with procedural and demographic data from our hospital Patient Administration System (PAS). The notes of all patients who died within 30 days were reviewed to collect data on co-morbid conditions, pre-operative investigations, post-operative thromboprophylaxis and cause of death. All primary and revision knee and hip arthroplasties including bilateral procedures were included. Arthroplasty for trauma was excluded. RESULTS: 12,243 patients underwent hip or knee arthroplasty within the study period. The male:female ratio was 2:3. The mean age was 68 with a range of 21-91. Ten patients died giving a 30-day mortality rate of 0.08%. The most common cause of death was myocardial infarction (7/10 patients). CONCLUSIONS: Our finding of a mortality rate of 0.08% is similar or lower to those found in previous studies. To our knowledge this is the first series of this size looking at mortality from hip and knee arthroplasty within a single centre in the UK.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Artroplastia de Reemplazo de Rodilla , Procedimientos Quirúrgicos Electivos , Complicaciones Posoperatorias/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia/tendencias , Reino Unido/epidemiología , Adulto Joven
4.
Microb Pathog ; 54: 1-19, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22960579

RESUMEN

Human Campylobacter jejuni infection can result in an asymptomatic carrier state, watery or bloody diarrhea, bacteremia, meningitis, or autoimmune neurological sequelae. Infection outcomes of C57BL/6 IL-10(-/-) mice orally infected with twenty-two phylogenetically diverse C. jejuni strains were evaluated to correlate colonization and disease phenotypes with genetic composition of the strains. Variation between strains was observed in colonization, timing of development of clinical signs, and occurrence of enteric lesions. Five pathotypes of C. jejuni in C57BL/6 IL-10(-/-) mice were delineated: little or no colonization, colonization without disease, colonization with enteritis, colonization with hemorrhagic enteritis, and colonization with neurological signs with or without enteritis. Virulence gene content of ten sequenced strains was compared in silico; virulence gene content of twelve additional strains was compared using a C. jejuni pan-genome microarray. Neither total nor virulence gene content predicted pathotype; nor was pathotype correlated with multilocus sequence type. Each strain was unique with regard to absences of known virulence-related loci and/or possession of point mutations and indels, including phase variation, in virulence-related genes. An experiment in C. jejuni 11168-infected germ-free mice showed that expression levels of ninety open reading frames (ORFs) were significantly up- or down-regulated in the mouse cecum at least two-fold compared to in vitro growth. Genomic content of these ninety C. jejuni 11168 ORFs was significantly correlated with the capacity to colonize and cause enteritis in C57BL/6 IL-10(-/-) mice. Differences in gene expression levels and patterns are thus an important determinant of pathotype in C. jejuni strains in this mouse model.


Asunto(s)
Infecciones por Campylobacter/inmunología , Infecciones por Campylobacter/patología , Campylobacter jejuni/inmunología , Campylobacter jejuni/patogenicidad , Interleucina-10/deficiencia , Sistemas de Lectura Abierta , Factores de Virulencia/genética , Animales , Infecciones por Campylobacter/microbiología , Campylobacter jejuni/clasificación , Campylobacter jejuni/genética , Femenino , Expresión Génica , Genotipo , Interleucina-10/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Tipificación de Secuencias Multilocus , Virulencia , Factores de Virulencia/metabolismo
5.
Nature ; 441(7089): 62-4, 2006 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-16672964

RESUMEN

The rotation rate of a planet is one of its fundamental properties. Saturn's rotation, however, is difficult to determine because there is no solid surface from which to time it, and the alternative 'clock'--the magnetic field--is nearly symmetrically aligned with the rotation axis. Radio emissions, thought to provide a proxy measure of the rotation of the magnetic field, have yielded estimates of the rotation period between 10 h 39 min 22 s and 10 h 45 min 45 s (refs 8-10). Because the period determined from radio measurements exhibits large time variations, even on timescales of months, it has been uncertain whether the radio-emission periodicity coincides with the inner rotation rate of the planet. Here we report magnetic field measurements that revealed a time-stationary magnetic signal with a period of 10 h 47 min 6 s +/- 40 s. The signal appears to be stable in period, amplitude and phase over 14 months of observations, pointing to a close connection with the conductive region inside the planet, although its interpretation as the 'true' inner rotation period is still uncertain.

6.
Spinal Cord ; 50(11): 844-7, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22584282

RESUMEN

STUDY DESIGN: Grounded theory. OBJECTIVES: To explore to better understand the decision-making process of people with tetraplegia regarding reconstructive upper limb (UL) surgery. SETTING: New Zealand. METHODS: In-depth interviews with 22 people with tetraplegia, 10 of whom had UL surgery and 12 had not. Verbatim transcripts were analysed using constructivist grounded theory. RESULTS: The primary reason for having reconstructive UL surgery was to improve independence and return to previous pastimes. Reasons not to have surgery were hope for further recovery or cure, and inadequate physical environment or social supports while rehabilitating. In addition, women identified the temporary loss of independence and need for increased care while rehabilitating as issues. Importantly, these issues were not static, often changing in importance or relevance over time. CONCLUSIONS: The moment of making the decision for reconstructive UL surgery is elusive; therefore, multiple offers of surgery at different timeframes in an individual's life are required. In addition, flexibility in timing for surgery would allow for surgery to better coordinate with an individual's goals and priorities.


Asunto(s)
Actitud Frente a la Salud , Procedimientos de Cirugía Plástica , Cuadriplejía/cirugía , Extremidad Superior/cirugía , Adulto , Toma de Decisiones , Femenino , Humanos , Masculino , Cuadriplejía/complicaciones
7.
Spinal Cord ; 48(11): 832-7, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20157314

RESUMEN

STUDY DESIGN: Retrospective case series. OBJECTIVE: To describe the uptake of upper limb surgery by individuals with tetraplegia in New Zealand (NZ). SETTING: New Zealand. METHODS: The clinical notes of all individuals who sustained a cervical spinal cord injury between 1 January 2001 and 31 December 2005 were retrospectively reviewed for those who met the clinical criteria to undergo upper limb surgery. Cases were cross-referenced to the hand surgery record to determine the uptake of upper limb surgery in this cohort. RESULTS: The uptake of upper limb surgery for people with tetraplegia in NZ was 44% of the eligible cohort and 59% of those assessed for surgery. This is notably higher than the reported proportion in other developed countries. The data also suggested that women and those who identified as NZ Maori were less likely to undergo upper limb surgery than were men and those of NZ European ethnicity. CONCLUSION: Utilization of upper limb surgery in the eligible tetraplegic population in NZ was high. However, it seemed that some groups were less likely to undergo surgery. Further research into the factors that affect an individual's decision to undergo upper limb surgery could explain the observed pattern.


Asunto(s)
Brazo/cirugía , Procedimientos Ortopédicos/estadística & datos numéricos , Procedimientos de Cirugía Plástica/estadística & datos numéricos , Cuadriplejía/cirugía , Traumatismos de la Médula Espinal/cirugía , Adolescente , Adulto , Anciano , Brazo/inervación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Ortopédicos/métodos , Procedimientos Ortopédicos/psicología , Cuadriplejía/etiología , Cuadriplejía/psicología , Procedimientos de Cirugía Plástica/métodos , Procedimientos de Cirugía Plástica/psicología , Estudios Retrospectivos , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/psicología , Adulto Joven
8.
Stem Cell Res Ther ; 11(1): 184, 2020 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-32430075

RESUMEN

BACKGROUND: Tendon injuries occur frequently in human and equine athletes. Treatment options are limited, and the prognosis is often poor with functionally deficient scar tissue resulting. Fetal tendon injuries in contrast are capable of healing without forming scar tissue. Embryonic stem cells (ESCs) may provide a potential cellular therapeutic to improve adult tendon regeneration; however, whether they can mimic the properties of fetal tenocytes is unknown. To this end, understanding the unique expression profile of normal adult and fetal tenocytes is crucial to allow validation of ESC-derived tenocytes as a cellular therapeutic. METHODS: Equine adult, fetal and ESC-derived tenocytes were cultured in a three-dimensional environment, with histological, morphological and transcriptomic differences compared. Additionally, the effects on gene expression of culturing adult and fetal tenocytes in either conventional two-dimensional monolayer culture or three-dimensional culture were compared using RNA sequencing. RESULTS: No qualitative differences in three-dimensional tendon constructs generated from adult, fetal and ESCs were found using histological and morphological analysis. However, genome-wide transcriptomic analysis using RNA sequencing revealed that ESC-derived tenocytes' transcriptomic profile more closely resembled fetal tenocytes as opposed to adult tenocytes. Furthermore, this study adds to the growing evidence that monolayer cultured cells' gene expression profiles converge, with adult and fetal tenocytes having only 10 significantly different genes when cultured in this manner. In contrast, when adult and fetal tenocytes were cultured in 3D, large distinctions in gene expression between these two developmental stages were found, with 542 genes being differentially expressed. CONCLUSION: The information provided in this study makes a significant contribution to the investigation into the differences between adult reparative and fetal regenerative cells and supports the concept of using ESC-derived tenocytes as a cellular therapy. Comparing two- and three-dimensional culture also indicates three-dimensional culture as being a more physiologically relevant culture system for determining transcriptomic difference between the same cell types from different developmental stages.


Asunto(s)
Células Madre Embrionarias , Tenocitos , Animales , Diferenciación Celular , Células Cultivadas , Perfilación de la Expresión Génica , Caballos , Humanos , Tendones
9.
Int J Cardiol ; 321: 24-29, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-32800911

RESUMEN

OBJECTIVE: We aimed to assess the use of enhanced stent visualisation (ESV) on outcomes, after PCI with overlapping stents, specifically using CLEARstent technology. BACKGROUND: Stent underexpansion and overlap are both significant risk factors for restenosis and stent thrombosis. Enhanced stent visualisation (e.g. CLEARstent) systems could provide important data to reduce under-expansion and stent overlap. METHODS: This was a cohort study based on this institution's percutaneous coronary intervention (PCI) registry. A total of 2614 patients who had PCI for stable angina or acute coronary syndromes (ACS, excluding cardiogenic shock) with overlapping 2nd generation drug eluting stents (DES) in the same vessel between May 2015 and January 2018 were included in the analysis. Patients were divided into ESV (n = 1354) and no ESV guided intervention (n = 1260). The primary end-point was major adverse cardiovascular events (MACE: target vessel revascularisation, target vessel myocardial infarction and all-cause mortality) recorded at a median follow up of 2.4 years. RESULTS: Groups were comparable for patient characteristics (age, diabetes mellitus, ACS presentation). A significant difference in MACE was observed between patients who underwent ESV-guided PCI (9.5%) compared with patients who underwent Standard PCI (14.4%, p = .018). This difference was mainly driven by reduced rates of target vessel revascularisation and recurrent myocardial infarction. Overall this difference persisted after multivariate Cox analysis (HR 0.86, 95% CI: 0.73-0.98) and propensity matching (HR = 0.88, 95% CI: 0.69-0.99). CONCLUSION: We suggest that routine clinical use of ESV technology during PCI can be useful, and is associated with better medium-term angiographic and clinical outcomes. Further study is required to build on this promising signal.


Asunto(s)
Intervención Coronaria Percutánea , Angiografía , Estudios de Cohortes , Angiografía Coronaria , Humanos , Intervención Coronaria Percutánea/efectos adversos , Factores de Riesgo , Stents , Resultado del Tratamiento
10.
Science ; 268(5213): 1005-7, 1995 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-7754377

RESUMEN

Ulysses has explored the field and particle environment of the sun's polar region. The solar wind speed was fast and nearly constant above -50 degrees latitude. Compositional differences were observed in slow (low-latitude) solar wind and in fast (high-latitude) solar wind. The radial magnetic field did not change with latitude, implying that polar cap magnetic fields are transported toward the equator. The intensity of galactic cosmic rays was nearly independent of latitude. Their access to the polar region is opposed by outward-traveling, large amplitude waves in the magnetic field.


Asunto(s)
Medio Ambiente Extraterrestre , Sistema Solar , Nave Espacial , Radiación Cósmica , Campos Electromagnéticos
11.
Science ; 257(5076): 1503-7, 1992 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-17776156

RESUMEN

In February 1992, the Ulysses spacecraft flew through the giant magnetosphere of Jupiter. The primary objective of the encounter was to use the gravity field of Jupiter to redirect the spacecraft to the sun's polar regions, which will now be traversed in 1994 and 1995. However, the Ulysses scientific investigations were well suited to observations of the Jovian magnetosphere, and the encounter has resulted in a major contribution to our understanding of this complex and dynamic plasma environment. Among the more exciting results are (i) possible entry into the polar cap, (ii) the identification of magnetospheric ions originating from Jupiter's ionosphere, lo, and the solar wind, (iii) observation of longitudinal asymmetries in density and discrete wave-emitting regions of the lo plasma torus, (iv) the presence of counter-streaming ions and electrons, field-aligned currents, and energetic electron and radio bursts in the dusk sector on high-latitude magnetic field lines, and (v) the identification of the direction of the magnetic field in the dusk sector, which is indicative of tailward convection. This overview serves as an introduction to the accompanying reports that present the preliminary scientific findings. Aspects of the encounter that are common to all of the investigations, such as spacecraft capabilities, the flight path past Jupiter, and unique aspects of the encounter, are presented herein.

12.
Science ; 268(5213): 1007-10, 1995 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-17774226

RESUMEN

Magnetic field measurements from the Ulysses space mission overthe south polar regions of the sun showed that the structure and properties of the three-dimensional heliosphere were determined by the fast solar wind flow and magnetic fields from the large coronal holes in the polar regions of the sun. This conclusion applies at the current, minimum phase of the 11-year solar activity cycle. Unexpectedly, the radial component of the magnetic field was independent of latitude. The high-latitude magnetic field deviated significantly from the expected Parker geometry, probably because of large amplitude transverse fluctuations. Low-frequency fluctuations had a high level of variance. The rate of occurrence of discontinuities also increased significantly at high latitudes.

13.
Science ; 232(4748): 377-81, 1986 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-17792149

RESUMEN

The plasma wave instrument on the International Cometary Explorer (ICE) detected bursts of strong ion acoustic waves almost continuously when the spacecraft was within 2 million kilometers of the nucleus of comet Giacobini-Zinner. Electromagnetic whistlers and low-level electron plasma oscillations were also observed in this vast region that appears to be associated with heavy ion pickup. As ICE came closer to the anticipated location of the bow shock, the electromagnetic and electrostatic wave levels increased significantly, but even in the midst of this turbulence the wave instrument detected structures with familiar bow shock characteristics that were well correlated with observations of localized electron heating phenomena. Just beyond the visible coma, broadband waves with amplitudes as high as any ever detected by the ICE plasma wave instrument were recorded. These waves may account for the significant electron heating observed in this region by the ICE plasma probe, and these observations of strong wave-particle interactions may provide answers to longstanding questions concerning ionization processes in the vicinity of the coma. Near closest approach, the plasma wave instrument detected broadband electrostatic noise and a changing pattern of weak electron plasma oscillations that yielded a density profile for the outer layers of the cold plasma tail. Near the tail axis the plasma wave instrument also detected a nonuniform flux of dust impacts, and a preliminary profile of the Giacobini-Zinner dust distribution for micrometer-sized particles is presented.

14.
Science ; 232(4748): 382-5, 1986 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-17792150

RESUMEN

The vector helium magnetometer on the International Cometary Explorer observed the magnetic fields induced by the interaction of comet Giacobini-Zinner with the solar wind. A magnetic tail was penetrated approximately 7800 kilometers downstream from the comet and was found to be 10(4) kilometers wide. It consisted of two lobes, containing oppositely directed fields with strengths up to 60 nanoteslas, separated by a plasma sheet approximately 10(3)kilometers thick containing a thin current sheet. The magnetotail was enclosed in an extended ionosheath characterized by intense hydromagnetic turbulene and interplanetary fields draped around the comet. A distant bow wave, which may or may not have been a bow shock, was observed at both edges of the ionosheath. Weak turbulence was observed well upstream of the bow wave.

15.
Science ; 207(4429): 407-10, 1980 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-17833549

RESUMEN

The Pioneer Saturn vector helium magnetometer has detected a bow shock and magnetopause at Saturn and has provided an accurate characterization of the planetary field. The equatorial surface field is 0.20 gauss, a factor of 3 to 5 times smaller than anticipated on the basis of attempted scalings from Earth and Jupiter. The tilt angle between the magnetic dipole axis and Saturn's rotation axis is < 1 degrees , a surprisingly small value. Spherical harmonic analysis of the measurements shows that the ratio of quadrupole to dipole moments is < 10 percent, indicating that the field is more uniform than those of the Earth or Jupiter and consistent with Saturn having a relatively small core. The field in the outer magnetosphere shows systematic departures from the dipole field, principally a compression of the field near noon and an equatorial orientation associated with a current sheet near dawn. A hydromagnetic wake resulting from the interaction of Titan with the rotating magnetosphere appears to have been observed.

16.
Science ; 158(3809): 1669-73, 1967 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-17749787

RESUMEN

Abrupt changes in the amplitude of the magnetic fluctuations, in the field strength, and in the plasma properties, were observed with Mariner V near Venus. They provide clear evidence for the presence of a bow shock around the planet, similar to, but much smaller than, that observed at Earth. The observations appear consistent with an interaction of the solar wind with the ionosphere of Venus. No planetary field could be detected, but a steady radial field and very low plasma density were found 10,000 to 20,000 kilometers behind Venus and 8,000 to 12,000 kilometers from the Sun-Venus line. These observations may be interpreted as relating to an expansion wave tending to fill the cavity produced by Venus in the solar wind. The upper limit to the magnetic dipole moment of Venus is estimated to be within a factor of 2 of 10(-3) items that of Earth.

17.
Science ; 183(4122): 305-6, 1974 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-17821088

RESUMEN

Jupiter's magnetic field and its interaction with the magnetized solar wind were observed with the Pioneer 10 vector helium magnetometer. The magnetic dipole is directed opposite to that of the earth with a moment of 4.0 gauss R(J)(3) (R(J), Jupiter radius), and an inclination of 15 degrees lying in a system III meridian of 230 degrees . The dipole is offset about 0.1 R(J) north of the equatorial plane and about 0.2 R(J) toward longitude 170 degrees . There is severe stretching of the planetary field parallel to the equator throughout the outer magnetosphere, accompanied by a systematic departure from meridian planes. The field configuration implies substantial plasma effects inside the magnetosphere, such as thermal pressure, centrifugal forces, and differential rotation. As at the earth, the outer boundary is thin, nor diffuse, and there is a detached bow shock.

18.
Science ; 188(4187): 451-5, 1975 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-17734359

RESUMEN

The Pioneer 11 vector helium magnetometer provided precise, contititious measurements of the magnetic fields in interplanetary space, inside Jupiter's magnetosphere, and in the near vicinity of Jupiter. As with the Pioneer 10 data, evidence was seen of the dynanmic interaction of Jupiter with the solar wind which leads to a variety of phenomena (bow shock, upstream waves, nonlinear magnetosheath impulses) and to changes in the dimension of the dayside magnetosphere by as much as a factor of 2. The magnetosphere clearly appears to be blunt, not disk-shaped, with a well-defined outer boundary. In the outer magnetosphere, the magnetic field is irregular but exhibits a persistent southward component indicative of a closed magnetosphere. The data contain the first clear evidence in the dayside magnetosphere of the current sheet, apparently associated with centrifugal forces, that was a donminatnt feature of the outbound Pionieer 10 data. A modest westward spiraling of the field was again evident inbound but not outbound at higher latitudes and nearer the Sun-Jupiter direction. Measurements near periapsis, which were nearer the planet and provide better latitude and longitude coverage than Pioneer 10, have revealed a 5 percent discrepancy with the Pioneer 10 offset dipole mnodel (D(2)). A revised offset dipole (6-parameter fit) is presented as well as the results of a spherical harmonic analysis (23 parameters) consisting of an interior dipole, quadrupole, and octopole and an external dipole and quadrupole. The dipole moment and the composite field appear moderately larger than inferred from Pioneer 10. Maximum surface fields of 14 and 11 gauss in the northern and southern hemispheres are inferred. Jupiter's planetary field is found to be slightly more irregular than that of Earth.

19.
Science ; 257(5076): 1515-8, 1992 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-17776160

RESUMEN

The Jovian flyby of the Ulysses spacecraft presented the opportunity to confirm and complement the findings of the four previous missions that investigated the structure and dynamics of the Jovian magnetosphere and magnetic field, as well as to explore for the first time the high-latitude dusk side of the magnetosphere and its boundary regions. In addition to confirming the general structure of the dayside magnetosphere, the Ulysses magnetic field measurements also showed that the importance of the current sheet dynamics extends well into the middle and outer magnetosphere. On the dusk side, the magnetic field is swept back significantly toward the magnetotail. The importance of current systems, both azimuthal and field-aligned, in determining the configuration of the field has been strongly highlighted by the Ulysses data. No significant changes have been found in the internal planetary field; however, the need to modify the external current densities with respect to previous observations on the inbound pass shows that Jovian magnetic and magnetospheric models are highly sensitive to both the intensity and the structure assumed for the current sheet and to any time dependence that may be assigned to these. The observations show that all boundaries and boundary layers in the magnetosphere have a very complex microstructure. Waves and wave-like structures were observed throughout the magnetosphere; these included the longest lasting mirror-mode wave trains observed in space.

20.
Anim Genet ; 40(2): 134-41, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19067672

RESUMEN

The mitochondrial genome (mtGenome) has been little studied in the turkey (Meleagris gallopavo), a species for which there is no publicly available mtGenome sequence. Here, we used PCR-based methods with 19 pairs of primers designed from the chicken and other species to develop a complete turkey mtGenome sequence. The entire sequence (16,717 bp) of the turkey mtGenome was obtained, and it exhibited 85% similarity to the chicken mtGenome sequence. Thirteen genes and 24 RNAs (22 tRNAs and 2 rRNAs) were annotated. An mtGenome-based phylogenetic analysis indicated that the turkey is most closely related to the chicken, Gallus gallus, and quail, Corturnix japonica. Given the importance of the mtGenome, the present work adds to the growing genomic resources needed to define the genetic mechanisms that underlie some economically significant traits in the turkey.


Asunto(s)
Evolución Molecular , Genoma Mitocondrial , Pavos/genética , Animales , Proteínas Aviares/genética , Secuencia de Bases , Pollos/genética , Coturnix/genética , Cartilla de ADN/genética , ADN Mitocondrial/genética , Filogenia , Reacción en Cadena de la Polimerasa , ARN Ribosómico/genética , ARN de Transferencia/genética , Especificidad de la Especie , Pavos/clasificación
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