Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 225
Filtrar
1.
Sci Rep ; 10(1): 7932, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32404966

RESUMO

Cassini's Grand Finale orbits provided for the first time in-situ measurements of Saturn's topside ionosphere. We present the Pedersen and Hall conductivities of the top near-equatorial dayside ionosphere, derived from the in-situ measurements by the Cassini Radio and Wave Plasma Science Langmuir Probe, the Ion and Neutral Mass Spectrometer and the fluxgate magnetometer. The Pedersen and Hall conductivities are constrained to at least 10-5-10-4 S/m at (or close to) the ionospheric peak, a factor 10-100 higher than estimated previously. We show that this is due to the presence of dusty plasma in the near-equatorial ionosphere. We also show the conductive ionospheric region to be extensive, with thickness of 300-800 km. Furthermore, our results suggest a temporal variation (decrease) of the plasma densities, mean ion masses and consequently the conductivities from orbit 288 to 292.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31091463

RESUMO

AMP-activated protein kinase (AMPK) is considered as the master cellular metabolism regulator that activates various proteins, including O-GlcNAc transferase (OGT). Physiological roles of AMPK and OGT, including the relationship between their mRNA expression and food intake, are poorly understood in channel catfish. This study examined the tissue distribution of AMPK and OGT mRNA and changes in their expression in response to changes in food intake in channel catfish. Expression of all AMPK subunit and OGT mRNA was detectable in the whole brain, liver, heart, spleen, white muscle, and kidney of channel catfish. The OGT mRNA was highly localized in the brain compared to other tissues. 28-day fasting increased hepatic expression of AMPK α1, ß1, and OGT mRNA while refeeding fish for 14 days after the 14-day fast decreased their expression to the level similar to that of fish that were fed daily. No changes were noted in the expression of muscle and brain AMPK mRNA or OGT mRNA by fasting and refeeding. Hepatic AMPK α1, α2 and ß1 mRNA decreased in response to increased feeding frequency, whereas no changes in the expression of AMPK or OGT mRNA were noted in the brain or the muscle. Results of the current study indicated that the hepatic expression of AMPK and OGT mRNA appeared to be more sensitive to changes in food intake in channel catfish. However, further studies are needed to clearly demonstrate if food intake influences the expression of AMPK and OGT mRNA in various tissues, including the hypothalamus.


Assuntos
Peixes-Gato/genética , N-Acetilglucosaminiltransferases/genética , Proteínas Quinases/genética , Quinases Proteína-Quinases Ativadas por AMP , Animais , Ingestão de Alimentos/genética , Regulação da Expressão Gênica/genética , Hipotálamo/enzimologia , Fígado/enzimologia , Músculos/enzimologia , RNA Mensageiro/genética , Distribuição Tecidual/genética
3.
Aliment Pharmacol Ther ; 47(8): 1071-1078, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29508432

RESUMO

BACKGROUND: Swallowed topical corticosteroids are prescribed for eosinophilic oesophagitis (EoE), but there is a theoretical risk of adrenal insufficiency from their use. AIMS: To determine if the use of topical corticosteroids to treat EoE is associated with the development of adrenal insufficiency. METHOD: We conducted a systematic review of the published literature from January 1, 1950 to April 1, 2017 using Pubmed, Embase, Web of Science and Cochrane Central. Studies and meeting abstracts were included that described patients with EoE who received swallowed topical corticosteroids and any investigation for adrenal insufficiency. RESULTS: The search revealed 1610 unique publications, and 17 met inclusion criteria. There were 7 randomised controlled trials (RCTs), 6 prospective observational studies, 3 retrospective observational studies, and 1 case report. Cortisol measurements were performed on 596 individuals with EoE who received topical corticosteroids. Adrenal testing was abnormal, as defined by each study, in 94/596 patients (crude rate of 15.8%). Only 2 studies were considered to have a low risk of bias, being randomised controlled trials that estimated adrenal insufficiency in the active treatment and placebo groups, before and after treatment. None of the seven randomised controlled trials demonstrated statistically significantly different rates of adrenal insufficiency between topical corticosteroid and placebo over treatment intervals of 2-12 weeks. CONCLUSION: Topical corticosteroids were associated with adrenal insufficiency in a minority of patients. Most cases came from uncontrolled observational studies, with widely varying definitions of adrenal insufficiency. Longer follow-up and larger controlled studies are needed to quantify the risk of adrenal insufficiency with maintenance topical corticosteroid therapy in EoE.


Assuntos
Corticosteroides/efeitos adversos , Insuficiência Adrenal/induzido quimicamente , Esofagite Eosinofílica/tratamento farmacológico , Administração Oral , Humanos , Estudos Observacionais como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
J Genet Couns ; 27(1): 16-20, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29052810

RESUMO

As of May 2017, there were 4242 Certified Genetic Counselors (CGC) (American Board of Genetic Counseling, Inc. 2017) and 41 graduate-level genetic counseling training programs (Accreditation Council for Genetic Counseling 2017) in North America, and the demand for CGCs continues to increase. In the Fall of 2015 the Genetic Counselor Workforce Working Group, comprised of representatives from the American Board of Genetic Counseling (ABGC), the Accreditation Council for Genetic Counseling (ACGC), the Association of Genetic Counseling Program Directors (AGCPD), the American Society of Human Genetics (ASHG), and the National Society of Genetic Counselors (NSGC) commissioned a formal workforce study to project supply of and demand for CGCs through 2026. The data indicate a shortage of genetic counselors engaged in direct patient care. Assuming two scenarios for demand, supply is expected to reach equilibrium between 2024 and 2030. However, given the rate of growth in genetic counseling training programs in the six months since the study was completed, it is reasonable to expect that the number of new programs may be higher than anticipated by 2026. If true, and assuming that growth in programs is matched by equivalent growth in clinical training slots, the supply of CGCs in direct patient care would meet demand earlier than these models predict.


Assuntos
Pessoal Técnico de Saúde/organização & administração , Certificação , Conselheiros/organização & administração , Aconselhamento Genético/organização & administração , Papel Profissional , Acreditação , Aconselhamento/organização & administração , Educação de Pós-Graduação , Humanos , Estados Unidos
5.
Pharm. care Esp ; 20(6): 442-477, 2018.
Artigo em Espanhol | IBECS | ID: ibc-176675

RESUMO

La inclusión reciente de farmacéuticos en atención primaria en Brasil a través del Equipo de Apoyo de Salud Familiar los ha alentado a reflexionar sobre la necesidad de dejar de ser un profesional enfocado en los medicamentos a un profesional enfocado en las personas. La autoetnografía le permitió a una farmacéutica confrontar sus perspectivas sobre la práctica clínica entre 2014 y 2016, período en el que ella decidió desafiar, como farmacéutica, su formación tradicional centrada en los medicamentos. Utilizando como marco teórico la práctica del Pharmaceutical Care que había impulsadoa la profesión farmacéutica a cambiar su enfoque hacia el paciente, los autores colaboraron en la construcción de un monólogo sobre lo que significa centrarse en el paciente,de manera que éste cautivara a los lectores. Los hallazgos de la investigación también respaldan la versatilidad de la aplicación del proceso reflexivo proporcionado por la autoetnografía. Durante el trabajo de campo, a través de una redacción reflexiva y la realización de entrevistas, la farmacéutica descubrió una nueva forma de relacionarse con el "cuidado" y los "pacientes" en su rutina diaria


The recent inclusion of pharmacists in primary healthcare in Brazil through the Family Health Support Team has encouraged them to reflect on the need to change from a professional focused on medications to one focusedon individuals. This autoethnography allowed a pharmacist to confront her perspectives on clinical practice between 2014 and 2016, a period when she decided to challenge her traditional training as a pharmacist centered on medications. Using pharmaceutical care practice as the theoretical framework that prompted the profession of pharmacy to change its focus to the patient, the authors collaborated to construct a monologue that engages readers in the meanings of becoming patient centered. The research findings also support the versatility of application of the reflective process provided by autoethnography. Through fieldwork, reflective writing and interviews, the pharmacist discovered a new way to relate to "caring" and "patients" in her daily routine


Assuntos
Humanos , Atenção Primária à Saúde , Atitude do Pessoal de Saúde , Antropologia Cultural , Educação em Farmácia/métodos , Brasil , Educação em Farmácia/organização & administração , Educação em Farmácia/ética
6.
Vasc Endovascular Surg ; 51(4): 199-202, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28424038

RESUMO

Open aortic aneurysm repair in the setting of bilateral hypogastric aneurysms is technically challenging. We present a novel technique for open surgical repair for bilateral hypogastric aneurysms using the Gore hybrid vascular graft (GVHG; W. L. Gore and Associates Inc, Flagstaff, Arizona). The GVHG is an expanded polytetrafluoroethylene graft with a nitinol stent at 1 end designed for hemodialysis access. The GVHG has been also been used for aortic debranching and treatment of occlusive disease. We describe the first report using GVHG to repair hypogastric aneurysms.


Assuntos
Aneurisma/cirurgia , Artérias/cirurgia , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Aneurisma Ilíaco/cirurgia , Pelve/irrigação sanguínea , Politetrafluoretileno , Stents , Idoso , Ligas , Aneurisma/diagnóstico por imagem , Artérias/diagnóstico por imagem , Angiografia por Tomografia Computadorizada , Feminino , Humanos , Aneurisma Ilíaco/diagnóstico por imagem , Desenho de Prótese , Resultado do Tratamento
7.
J Geophys Res Space Phys ; 121(1): 338-357, 2016 01.
Artigo em Inglês | MEDLINE | ID: mdl-27610291

RESUMO

Studies of Saturn's magnetosphere with the Cassini mission have established the importance of Enceladus as the dominant mass source for Saturn's magnetosphere. It is well known that the ionosphere is an important mass source at Earth during periods of intense geomagnetic activity, but lesser attention has been dedicated to study the ionospheric mass source at Saturn. In this paper we describe a case study of data from Saturn's magnetotail, when Cassini was located at ≃ 2200 h Saturn local time at 36 RS from Saturn. During several entries into the magnetotail lobe, tailward flowing cold electrons and a cold ion beam were observed directly adjacent to the plasma sheet and extending deeper into the lobe. The electrons and ions appear to be dispersed, dropping to lower energies with time. The composition of both the plasma sheet and lobe ions show very low fluxes (sometimes zero within measurement error) of water group ions. The magnetic field has a swept-forward configuration which is atypical for this region, and the total magnetic field strength is larger than expected at this distance from the planet. Ultraviolet auroral observations show a dawn brightening, and upstream heliospheric models suggest that the magnetosphere is being compressed by a region of high solar wind ram pressure. We interpret this event as the observation of ionospheric outflow in Saturn's magnetotail. We estimate a number flux between (2.95 ± 0.43) × 109 and (1.43 ± 0.21) × 1010 cm-2 s-1, 1 or about 2 orders of magnitude larger than suggested by steady state MHD models, with a mass source between 1.4 ×102 and 1.1 ×103 kg/s. After considering several configurations for the active atmospheric regions, we consider as most probable the main auroral oval, with associated mass source between 49.7 ±13.4 and 239.8 ±64.8 kg/s for an average auroral oval, and 10 ±4 and 49 ±23 kg/s for the specific auroral oval morphology found during this event. It is not clear how much of this mass is trapped within the magnetosphere and how much is lost to the solar wind.

8.
Phys Rev Lett ; 115(12): 125001, 2015 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-26430997

RESUMO

Shock waves exist throughout the Universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this Letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasiperpendicular shocks across 2 orders of magnitude in Alfvén Mach number (M_{A}) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted time scale of ~0.3τ_{c}, where τ_{c} is the ion gyroperiod. In addition, we experimentally reveal the relationship between reformation and M_{A} and focus on the magnetic structure of such shocks to further show that for the same M_{A}, a reforming shock exhibits stronger magnetic field amplification than a shock that is not reforming.

9.
J Geophys Res Space Phys ; 120(5): 3603-3617, 2015 05.
Artigo em Inglês | MEDLINE | ID: mdl-27570722

RESUMO

We present a case study of an event from 20 August (day 232) of 2006, when the Cassini spacecraft was sampling the region near 32 RS and 22 h LT in Saturn's magnetotail. Cassini observed a strong northward-to-southward turning of the magnetic field, which is interpreted as the signature of dipolarization of the field as seen by the spacecraft planetward of the reconnection X line. This event was accompanied by very rapid (up to ~1500 km s-1) thermal plasma flow toward the planet. At energies above 28 keV, energetic hydrogen and oxygen ion flow bursts were observed to stream planetward from a reconnection site downtail of the spacecraft. Meanwhile, a strong field-aligned beam of energetic hydrogen was also observed to stream tailward, likely from an ionospheric source. Saturn kilometric radiation emissions were stimulated shortly after the observation of the dipolarization. We discuss the field, plasma, energetic particle, and radio observations in the context of the impact this reconnection event had on global magnetospheric dynamics.

10.
Geophys Res Lett ; 42(17): 6890-6898, 2015 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-27609998

RESUMO

For over 10 years, the Cassini spacecraft has patrolled Saturn's magnetosphere and observed its magnetopause boundary over a wide range of prevailing solar wind and interior plasma conditions. We now have data that enable us to resolve a significant dawn-dusk asymmetry and find that the magnetosphere extends farther from the planet on the dawnside of the planet by 7 ± 1%. In addition, an opposing dawn-dusk asymmetry in the suprathermal plasma pressure adjacent to the magnetopause has been observed. This probably acts to reduce the size asymmetry and may explain the discrepancy between the degree of asymmetry found here and a similar asymmetry found by Kivelson and Jia (2014) using MHD simulations. Finally, these observations sample a wide range of season, allowing the "intrinsic" polar flattening (14 ± 1%) caused by the magnetodisc to be separated from the seasonally induced north-south asymmetry in the magnetopause shape found theoretically (5 ± 1% when the planet's magnetic dipole is tilted away from the Sun by 10-17°).

11.
J Geophys Res Space Phys ; 120(9): 7289-7306, 2015 09.
Artigo em Inglês | MEDLINE | ID: mdl-27867793

RESUMO

Saturn's magnetic field acts as an obstacle to solar wind flow, deflecting plasma around the planet and forming a cavity known as the magnetosphere. The magnetopause defines the boundary between the planetary and solar dominated regimes, and so is strongly influenced by the variable nature of pressure sources both outside and within. Following from Pilkington et al. (2014), crossings of the magnetopause are identified using 7 years of magnetic field and particle data from the Cassini spacecraft and providing unprecedented spatial coverage of the magnetopause boundary. These observations reveal a dynamical interaction where, in addition to the external influence of the solar wind dynamic pressure, internal drivers, and hot plasma dynamics in particular can take almost complete control of the system's dayside shape and size, essentially defying the solar wind conditions. The magnetopause can move by up to 10-15 planetary radii at constant solar wind dynamic pressure, corresponding to relatively "plasma-loaded" or "plasma-depleted" states, defined in terms of the internal suprathermal plasma pressure.

12.
J Geophys Res Space Phys ; 119(3): 1994-2008, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26167441

RESUMO

We examine a unique data set from seven Hubble Space Telescope (HST) "visits" that imaged Saturn's northern dayside ultraviolet emissions exhibiting usual circumpolar "auroral oval" morphologies, during which Cassini measured the interplanetary magnetic field (IMF) upstream of Saturn's bow shock over intervals of several hours. The auroras generally consist of a dawn arc extending toward noon centered near ∼15° colatitude, together with intermittent patchy forms at ∼10° colatitude and poleward thereof, located between noon and dusk. The dawn arc is a persistent feature, but exhibits variations in position, width, and intensity, which have no clear relationship with the concurrent IMF. However, the patchy postnoon auroras are found to relate to the (suitably lagged and averaged) IMF Bz , being present during all four visits with positive Bz and absent during all three visits with negative Bz . The most continuous such forms occur in the case of strongest positive Bz . These results suggest that the postnoon forms are associated with reconnection and open flux production at Saturn's magnetopause, related to the similarly interpreted bifurcated auroral arc structures previously observed in this local time sector in Cassini Ultraviolet Imaging Spectrograph data, whose details remain unresolved in these HST images. One of the intervals with negative IMF Bz however exhibits a prenoon patch of very high latitude emission extending poleward of the dawn arc to the magnetic/spin pole, suggestive of the occurrence of lobe reconnection. Overall, these data provide evidence of significant IMF dependence in the morphology of Saturn's dayside auroras. KEY POINTS: We examine seven cases of joint HST Saturn auroral images and Cassini IMF dataThe persistent but variable dawn arc shows no obvious IMF dependencePatchy postnoon auroras are present for northward IMF but not for southward IMF.

13.
Geophys Res Lett ; 41(5): 1382-1388, 2014 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-25821276

RESUMO

We report on the first analysis of magnetospheric cusp observations at Saturn by multiple in situ instruments onboard the Cassini spacecraft. Using this we infer the process of reconnection was occurring at Saturn's magnetopause. This agrees with remote observations that showed the associated auroral signatures of reconnection. Cassini crossed the northern cusp around noon local time along a poleward trajectory. The spacecraft observed ion energy-latitude dispersions-a characteristic signature of the terrestrial cusp. This ion dispersion is "stepped," which shows that the reconnection is pulsed. The ion energy-pitch angle dispersions suggest that the field-aligned distance from the cusp to the reconnection site varies between ∼27 and 51 RS . An intensification of lower frequencies of the Saturn kilometric radiation emissions suggests the prior arrival of a solar wind shock front, compressing the magnetosphere and providing more favorable conditions for magnetopause reconnection. KEY POINTS: We observe evidence for reconnection in the cusp plasma at SaturnWe present evidence that the reconnection process can be pulsed at SaturnSaturn's cusp shows similar characteristics to the terrestrial cusp.

14.
Geophys Res Lett ; 41(10): 3323-3330, 2014 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-26074636

RESUMO

We present observations of significant dynamics within two UV auroral storms observed on Saturn using the Hubble Space Telescope in April/May 2013. Specifically, we discuss bursts of auroral emission observed at the poleward boundary of a solar wind-induced auroral storm, propagating at ∼330% rigid corotation from near ∼01 h LT toward ∼08 h LT. We suggest that these are indicative of ongoing, bursty reconnection of lobe flux in the magnetotail, providing strong evidence that Saturn's auroral storms are caused by large-scale flux closure. We also discuss the later evolution of a similar storm and show that the emission maps to the trailing region of an energetic neutral atom enhancement. We thus identify the auroral form with the upward field-aligned continuity currents flowing into the associated partial ring current.

15.
Geophys Res Lett ; 41(20): 7011-7018, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26074639

RESUMO

On 26 September 2005, Cassini conducted its only close targeted flyby of Saturn's small, irregularly shaped moon Hyperion. Approximately 6 min before the closest approach, the electron spectrometer (ELS), part of the Cassini Plasma Spectrometer (CAPS) detected a field-aligned electron population originating from the direction of the moon's surface. Plasma wave activity detected by the Radio and Plasma Wave instrument suggests electron beam activity. A dropout in energetic electrons was observed by both CAPS-ELS and the Magnetospheric Imaging Instrument Low-Energy Magnetospheric Measurement System, indicating that the moon and the spacecraft were magnetically connected when the field-aligned electron population was observed. We show that this constitutes a remote detection of a strongly negative (∼ -200 V) surface potential on Hyperion, consistent with the predicted surface potential in regions near the solar terminator.

16.
Astrobiology ; 13(10): 991-1004, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24143869

RESUMO

In this paper, we provide a detailed review of Ganymede's characteristics that are germane to any consideration of its planetary protection requirements. Ganymede is the largest moon in our solar system and is the subject of one of the main science objectives of the JUICE mission to the jovian system. We explore the probability of the occurrence of potentially habitable zones within Ganymede at present, including those both within the deep liquid ocean and those in shallow liquid reservoirs. We consider the possible exchange processes between the surface and any putative habitats to set some constraints on the planetary protection approach for this moon. As a conclusion, the "remote" versus "significant" chance of contamination will be discussed, according to our current understanding of this giant icy moon. Based on the different estimates we investigate here, it appears extremely unlikely that material would be exchanged downward through the upper icy layer of Ganymede and, thus, bring material into the ocean over timescales consistent with the survival of microorganisms.


Assuntos
Meio Ambiente Extraterreno , Júpiter , Exobiologia , Gelo , Temperatura
17.
J Food Sci ; 77(6): S211-5, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22591245

RESUMO

UNLABELLED: During smoked salmon processing, the dark meat along the lateral line is removed before packaging; this by-product currently has little economic value. In this study, the dark meat trim was incorporated into an extruded jerky. Three formulations were processed: 100% smoked trim, 75% : 25% smoked trim : fresh salmon fillet, and 50% : 50% smoked trim : fresh salmon blends (w/w basis). The base formulation contained salmon (approximately 83.5%), tapioca starch (8%), pregelatinized potato starch (3%), sucrose (4%), salt (1.5%), sodium nitrate (0.02%), and ascorbyl palmitate (0.02% of the lipid content). Blends were extruded in a laboratory-scale twin-screw extruder and then hot-smoked for 5 h. There were no significant differences among formulations in moisture, water activity, and pH. Protein was highest in the 50 : 50 blend jerky. Ash content was highest in the jerky made with 100% trim. Total lipids and salt were higher in the 100% trim jerky than in the 50 : 50 blend. Hot smoking did not adversely affect docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) content in lipids from 100% smoked trim jerky. Servings of salmon jerky made with 75% and 100% smoked trim provided at least 500 mg of EPA and DHA. The 50 : 50 formulation had the highest Intl. Commission on Illumination (CIE) L*, a*, and b* color values. Seventy consumers rated all sensory attributes as between "like slightly" and "like moderately." With some formulation and processing refinements, lateral line trim from smoked salmon processors has potential to be incorporated into acceptable, healthful snack products. PRACTICAL APPLICATION: Dark meat along the lateral line is typically discarded by smoked salmon processors. This omega-3 fatty acid rich by-product can be used to make a smoked salmon jerky that provides a convenient source of these healthful lipids for consumers.


Assuntos
Fast Foods/análise , Ácidos Graxos Ômega-3/análise , Produtos Pesqueiros/análise , Manipulação de Alimentos , Alimentos em Conserva/análise , Resíduos Industriais/análise , Salmo salar , Animais , Comportamento do Consumidor , Gorduras na Dieta/análise , Proteínas Alimentares/análise , Fast Foods/economia , Feminino , Produtos Pesqueiros/economia , Proteínas de Peixes/análise , Preferências Alimentares , Alimentos em Conserva/economia , Indústria de Processamento de Alimentos/economia , Humanos , Resíduos Industriais/economia , Masculino , Fenômenos Mecânicos , Pigmentação , Sensação , Fumaça , Cloreto de Sódio na Dieta/análise
19.
Clin Neuropathol ; 30(5): 235-41, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21955927

RESUMO

Two unrelated female infants presented at 9 days and 2 months, respectively, with apneic episodes in the former and gaze preference in the latter. MRI revealed enlargement of almost the entire right hemisphere, apparently smooth cortex, simplification of the gyral pattern, and expanded white matter with abnormal signal intensity containing multiple intraparenchymal cysts. Histologic examination of both cases revealed white matter infiltration by a hypocellular lesion composed of uniform, fibrillary astrocytes in a microcystic background. Multilocular tumor cysts were prominent, but Rosenthal fibers and eosinophilic granular bodies were absent. Very rare mitoses were seen in the absence of necrosis or vascular change. There was no convincing cortical infiltration, but the subpial zone was diffusely expanded by a band of astrocytes set in a dense fibrillar feltwork which opened out into numerous cystic spaces. No desmoplastic changes or associated atypical ganglion cells were identified. There was no evidence for a BRAFKIAA1549 fusion or BRAF mutation in one case tested. In conclusion, both lesions are not desmoplastic infantile astrocytoma/ganglioglioma, fibrillary astrocytoma, or typical for pilocytic astrocytoma. Such extreme subpial spread with cysts is most unusual and may suggest a novel variant of infantile astrocytoma.


Assuntos
Astrocitoma/patologia , Neoplasias Encefálicas/patologia , Cistos/patologia , Astrocitoma/metabolismo , Neoplasias Encefálicas/metabolismo , Cistos/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Recém-Nascido
20.
CBE Life Sci Educ ; 10(3): 318-27, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21885828

RESUMO

Science education in the United States will increasingly be driven by testing and accountability requirements, such as those mandated by the No Child Left Behind Act, which rely heavily on learning outcomes, or "standards," that are currently developed on a state-by-state basis. Those standards, in turn, drive curriculum and instruction. Given the importance of standards to teaching and learning, we investigated the quality of life sciences/biology standards with respect to genetics for all 50 states and the District of Columbia, using core concepts developed by the American Society of Human Genetics as normative benchmarks. Our results indicate that the states' genetics standards, in general, are poor, with more than 85% of the states receiving overall scores of Inadequate. In particular, the standards in virtually every state have failed to keep pace with changes in the discipline as it has become genomic in scope, omitting concepts related to genetic complexity, the importance of environment to phenotypic variation, differential gene expression, and the differences between inherited and somatic genetic disease. Clearer, more comprehensive genetics standards are likely to benefit genetics instruction and learning, help prepare future genetics researchers, and contribute to the genetic literacy of the U.S. citizenry.


Assuntos
Currículo/normas , Genética/educação , Genética/normas , Instituições Acadêmicas/normas , Humanos , Ensino/normas , Estados Unidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...