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1.
J Nutr Health Aging ; 26(11): 973-980, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36437764

RESUMEN

OBJECTIVES: Understanding how aging impacts swallowing can help differentiate typical from atypical behaviors. This study aimed to quantify age-related swallowing alterations observed during a modified barium swallow study. DESIGN: Cross-sectional study. SETTING: Adult fluoroscopy suite in a metropolitan hospital at an academic center. PARTICIPANTS: 195 healthy adults distributed across 3 age categories: 21-39; 40-59; 60+ years. MEASUREMENTS: 17 physiologic components of swallowing across three functional domains (oral, pharyngeal, esophageal), including summed composite scores (Oral Total [OT] and Pharyngeal Total [PT]), from the validated and standardized Modified Barium Swallow Impairment Profile. RESULTS: Most components (65%) demonstrated no impairment (scores of "0"). The odds of a worse (higher) score increased significantly with age for: Tongue Control during Bolus Hold, Hyolaryngeal Movement, Laryngeal Closure, Pharyngeal Contraction, and Pharyngoesophageal Segment Opening. OT and PT scores for 40-59-year-olds were worse than the youngest group (p=.01 and p <.001, respectively). Adults 60+ years had significantly worse PT scores among all groups (p-values <.01). CONCLUSION: Oropharyngeal swallowing physiology evolves as healthy adults age and should be considered during clinical decision-making.


Asunto(s)
Trastornos de Deglución , Deglución , Humanos , Deglución/fisiología , Bario , Estudios Transversales , Fluoroscopía
2.
J Low Temp Phys ; 199(3-4)2020.
Artículo en Inglés | MEDLINE | ID: mdl-33487736

RESUMEN

We describe the design and measurement of feedhorn-coupled, transition-edge sensor (TES) polarimeters with two passbands centered at 220 GHz and 280 GHz, intended for observations of the cosmic microwave background. Each pixel couples polarized light in two linear polarizations by use of a planar orthomode transducer and senses power via four TES bolometers, one for each band in each linear polarization. Previous designs of this detector architecture incorporated passbands from 27 to 220 GHz; we now demonstrate this technology at frequencies up to 315 GHz. Observational passbands are defined with an on-chip diplexer, and Fourier-transform-spectrometer measurements are in excellent agreement with simulations. We find coupling from feedhorn to TES bolometer using a cryogenic, temperature-controlled thermal source. We determine the optical efficiency of our device is η = 77% ± 6% (75% ± 5%) for 220 (280) GHz, relative to the designed passband shapes. Lastly, we compare two power-termination schemes commonly used in wide-bandwidth millimeter-wave polarimeters and find equal performance in terms of optical efficiency and passband shape.

3.
Phys Rev Lett ; 123(18): 181301, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31763885

RESUMEN

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500 deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.

4.
J Low Temp Phys ; 193(3-4)2018.
Artículo en Inglés | MEDLINE | ID: mdl-34815585

RESUMEN

Microwave Kinetic Inductance Detectors (MKIDs) provide a compelling path forward to the large-format polarimeter, imaging, and spectrometer arrays needed for next-generation experiments in millimeter-wave cosmology and astronomy. We describe the development of feedhorn-coupled MKID detectors for the TolTEC millimeter-wave imaging polarimeter being constructed for the 50-meter Large Millimeter Telescope (LMT). Observations with TolTEC are planned to begin in early 2019. TolTEC will comprise ∼7,000 polarization sensitive MKIDs and will represent the first MKID arrays fabricated and deployed on monolithic 150 mm diameter silicon wafers - a critical step towards future large-scale experiments with over 105 detectors. TolTEC will operate in observational bands at 1.1, 1.4, and 2.0 mm and will use dichroic filters to define a physically independent focal plane for each passband, thus allowing the polarimeters to use simple, direct-absorption inductive structures that are impedance matched to incident radiation. This work is part of a larger program at NIST-Boulder to develop MKID-based detector technologies for use over a wide range of photon energies spanning millimeter-waves to X-rays. We present the detailed pixel layout and describe the methods, tools, and flexible design parameters that allow this solution to be optimized for use anywhere in the millimeter and sub-millimeter bands. We also present measurements of prototype devices operating in the 1.1 mm band and compare the observed optical performance to that predicted from models and simulations.

5.
Ann R Coll Surg Engl ; 98(2): 77-9, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26829665

RESUMEN

'Continuous effort, not strength or intelligence, is the key to understanding our potential.' Margaret J Wheatley. The focus of any academic or research author is to share his or her findings, and to gain respect and reward for publishing. The ideal journal is one that not only publishes an article quickly but also helps the author to improve the article before publication through peer review, selects only the best research so that the author's article lies alongside other high quality articles, and provides maximum (and long-term) visibility and access to the article. Unfortunately, in the real world, authors need to make tradeoffs between high quality journals, those that work quickly, those that are willing to accept the article and those that provide the best access. Into this mix has come the potential of open access as a means of increasing visibility: journals publish the article without a subscription barrier so anyone, anywhere, can read the article. However, the growth of open access (pushed by institutions, grant bodies and governments as a means of improving human health and knowledge) has come with some unforeseen consequences. In this article, Jeffrey Beall discusses one recent phenomenon that has arisen from the open access movement: that of 'predatory publishers'. These are individuals or companies that use the open access financial system (author pays, rather than library subscribes) to defraud authors and readers by promising reputable publishing platforms but delivering nothing of the sort. They frequently have imaginary editorial boards, do not operate any peer review or quality control, are unclear about payment requirements and opaque about ownership or location, include plagiarised content and publish whatever somebody will pay them to publish. Predatory publishers generally make false promises to authors and behave unethically. They also undermine the scholarly information and publishing environment with a deluge of poor quality, unchecked and invalidated articles often published on temporary sites, thus losing the scholarly record. Jeffrey Beall, a librarian in Denver, US, has watched the rise of such fraudulent practice, and manages a blog site that names publishers and journals that he has identified as predatory. While Beall's lists can provide librarians and knowledgeable authors with information on which journals and publishers to be cautious about, several legitimate publishers, library groups and others have joined forces to educate and inform authors in what to look for when selecting journals to publish in (or read). This initiative, called Think. Check. Submit. (http://thinkchecksubmit.org/), was launched in the latter half of 2015 and hopes to raise awareness of disreputable journals while clearly separating them from valid, high quality, open access journals (of which there are many). PIPPA SMART Guest Editor.


Asunto(s)
Cirugía General , Publicaciones Periódicas como Asunto/normas , Edición/normas , Humanos
6.
Phys Rev Lett ; 111(14): 141301, 2013 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-24138230

RESUMEN

Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable.

7.
Appl Opt ; 52(36): 8747-58, 2013 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-24513939

RESUMEN

The increasing scale of cryogenic detector arrays for submillimeter and millimeter wavelength astrophysics has led to the need for large aperture, high index of refraction, low loss, cryogenic refracting optics. Silicon with n=3.4, low loss, and high thermal conductivity is a nearly optimal material for these purposes but requires an antireflection (AR) coating with broad bandwidth, low loss, low reflectance, and a matched coefficient of thermal expansion. We present an AR coating for curved silicon optics comprised of subwavelength features cut into the lens surface with a custom three-axis silicon dicing saw. These features constitute a metamaterial that behaves as a simple dielectric coating. We have fabricated silicon lenses as large as 33.4 cm in diameter with micromachined layers optimized for use between 125 and 165 GHz. Our design reduces average reflections to a few tenths of a percent for angles of incidence up to 30° with low cross polarization. We describe the design, tolerance, manufacture, and measurements of these coatings and present measurements of the optical properties of silicon at millimeter wavelengths at cryogenic and room temperatures. This coating and lens fabrication approach is applicable from centimeter to submillimeter wavelengths and can be used to fabricate coatings with greater than octave bandwidth.

8.
Rev Sci Instrum ; 83(9): 093113, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23020368

RESUMEN

Improvements in superconductor device fabrication, detector hybridization techniques, and superconducting quantum interference device readout have made square-centimeter-sized arrays of gamma-ray microcalorimeters, based on transition-edge sensors (TESs), possible. At these collecting areas, gamma microcalorimeters can utilize their unprecedented energy resolution to perform spectroscopy in a number of applications that are limited by closely-spaced spectral peaks, for example, the nondestructive analysis of nuclear materials. We have built a 256 pixel spectrometer with an average full-width-at-half-maximum energy resolution of 53 eV at 97 keV, a useable dynamic range above 400 keV, and a collecting area of 5 cm(2). We have demonstrated multiplexed readout of the full 256 pixel array with 236 of the pixels (91%) giving spectroscopic data. This is the largest multiplexed array of TES microcalorimeters to date. This paper will review the spectrometer, highlighting the instrument design, detector fabrication, readout, operation of the instrument, and data processing. Further, we describe the characterization and performance of the newest 256 pixel array.

9.
Curr Biol ; 11(15): 1183-7, 2001 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-11516949

RESUMEN

Fundamental to the process of mammalian development is the timed and coordinated regulation of gene expression. This requires transcription of a precise subset of the total complement of genes. It is clear that chromatin architecture plays a fundamental role in this process by either facilitating or restricting transcription factor binding [1]. How such specialized chromatin structures are established to regulate gene expression is poorly understood. All eukaryotic organisms contain specialized histone variants with distinctly different amino acid sequences that are even more conserved than the major core histones [2]. On the basis of their highly conserved sequence, histone variants have been assumed critical for the function of mammalian chromatin; however, a requirement for a histone variant has not been shown in mammalian cells. Mice with a deletion of H1 degrees have been generated by gene targeting in ES cells, but these mice show no phenotypic consequences, perhaps due to redundancy of function [3]. Here we show for the first time that a mammalian histone variant, H2A.Z, plays a critical role in early development, and we conclude that this histone variant plays a pivotal role in establishing the chromatin structures required for the complex patterns of gene expression essential for normal mammalian development.


Asunto(s)
Desarrollo Embrionario y Fetal/fisiología , Histonas/fisiología , Animales , Secuencia de Bases , Línea Celular , Cartilla de ADN , Eliminación de Gen , Histonas/genética , Ratones
10.
J Org Chem ; 65(20): 6508-14, 2000 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-11052095

RESUMEN

A novel strategy for the synthesis of D,L-glucosylceramide 1, a member of the glycosphingolipid class of natural products is described. Reagent-controlled asymmetric Brown allylboration gave excellent stereochemical control in the construction of adjacent stereocenters in the sphingoid base portion of the molecule. The trans-configured double bond was obtained as a single geometrical isomer by use of silicon-tethered olefin metathesis employing the Schrock carbene [(CF3)2MeCO]2Mo(=CHCMe2Ph)(=NC6H3-2,6-i-Pr2++ +) and in situ PhLi-induced ring-opening of the intermediate 5,6-dihydro-2H-1,2-oxasiline followed by protodesilylation with TBAF in DMSO. The synthesis was completed by long chain amide formation and global deprotection.


Asunto(s)
Glicoesfingolípidos/síntesis química , Alquenos , Compuestos Alílicos , Compuestos de Boro , Glucosilceramidas/síntesis química , Ozono
11.
Environ Health Perspect ; 106 Suppl 1: 383-5, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9539034

RESUMEN

The U.S. Department of Energy (U.S. DOE) maintains several programs to study and understand the health and environmental effects of exposure to low levels of energy-related agents. These programs include research to understand the mechanisms of action of agents of concern and to assess the risks associated with exposures of people and ecological systems to these agents. They also include implementing appropriate occupational safety and health standards and remediating waste sites to environmental standards. These programs require that the U.S. DOE pursue a realistic understanding of the effects of exposures to small amounts of energy-related agents. The largest of these programs involves hazardous waste remediation and includes potentially harmful exposures to low levels of numerous agents. The U.S. DOE conducts research to establish the scientific bases for the realistic assessment of risks of exposure to such wastes. As part of the U.S. DOE efforts to understand the risks of low-level exposures to hazardous waste, the Office of Health and Environmental Research and the Office of Environmental Management recently launched a broad cooperative program. It is comprised of research projects in nine general scientific areas and includes research on the health impacts and risk estimation of exposure to low levels of hazardous wastes. Projects for this new cooperative research program were selected from 610 applications and totaled approximately $47 million in fiscal year 1996. This program marks a new approach by using basic research to reduce cleanup costs and to develop scientific foundations for advances in environmental technologies. The research will also examine the effects of exposure to low levels of chemical and radiological wastes.


Asunto(s)
Residuos Peligrosos/efectos adversos , Humanos
12.
Nucleic Acids Res ; 24(13): 2511-8, 1996 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-8692689

RESUMEN

In an effort to understand how the heme biosynthetic pathway is uniquely regulated in erythroid cells, we examined the structure of the gene encoding murine delta-aminolevulinate dehydratase (ALAD; EC4.2.1.24), which is the second enzyme of the pathway. The gene contains two first exons, named 1A and 1B, which are alternatively spliced to exon 2, where the coding region begins. Each first exon has its own promoter. The promoter driving exon 1A expression is TATA-less and contains many GC boxes. In contrast, the exon 1B promoter bears regulatory sequences similar to those found for beta-globin and other erythroid-specific genes. Tissue distribution studies reveal that ALAD mRNA containing axon 1A is ubiquitous, whereas mRNA containing axon 1B is found only in erythroid tissues. This finding, together with our further observation that GATA-1 mRNA levels increase 3-fold during maturation of murine erythroid progenitor cells, may help explain simultaneous 3-fold increases in exon 1B expression. The unexpected result that axon 1A expression also increases 3-fold during CFU-E maturation may be attributable to the action of NF-E2, since there is a potential binding site in a position analogous to the NF-E2 site in the locus control region of the beta-globin gene cluster.


Asunto(s)
Eritropoyesis/genética , Regulación del Desarrollo de la Expresión Génica , Porfobilinógeno Sintasa/genética , Animales , Secuencia de Bases , Cromosomas Humanos Par 9 , Codón Iniciador , Proteínas de Unión al ADN/biosíntesis , Factores de Unión al ADN Específico de las Células Eritroides , Exones , Factor de Transcripción GATA1 , Humanos , Ratones , Datos de Secuencia Molecular , Factor de Transcripción NF-E2 , Subunidad p45 del Factor de Transcripción NF-E2 , Iniciación de la Cadena Peptídica Traduccional , Empalme del ARN , ARN Mensajero/genética , Ratas , Especificidad de la Especie , Distribución Tisular , Factores de Transcripción/biosíntesis , Transcripción Genética
13.
Gend Dev ; 4(1): 9-16, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12346985

RESUMEN

PIP: Women's priorities have often been ignored in the design of human settlements, the location of housing, and the provision of urban services. New forms of urban partnership are needed to develop participatory processes which include women and men at all stages of urban development. Participation is most commonly associated with political participation or activity. The author gives an overview of the "gendered city", then looks at how men and women benefit and contribute to urban life, through examples of opportunities for making a living and for using urban resources and services. She then moves away from participation as entitlement to consider participation as empowerment, looking at some problems faced by women in public office and grassroots organizations. The paper concludes in arguing that a gender perspective will not inform urban policy and planning processes automatically. Sections discuss gender and poverty in the city, making a living in the city, urban planning as a gender issue, getting around the city, access to resources and services, violence in the city, women's participation in urban governance, women's representation in public office, community organization and advocacy, men and gender issues, and forging linkages through participation.^ieng


Asunto(s)
Planificación en Salud , Relaciones Interpersonales , Población Urbana , Urbanización , Derechos de la Mujer , Conducta , Demografía , Economía , Geografía , Organización y Administración , Población , Características de la Población , Conducta Social , Factores Socioeconómicos
14.
Cytotechnology ; 5(3): 223-31, 1991 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1367549

RESUMEN

A model mammalian cell system for the production of recombinant proteins was investigated. Murine myeloma cells which had lost the ability to produce both heavy and light chain immunoglobulin molecules were transfected with a vector containing the immunoglobulin heavy chain promoter and enhancer elements linked to the human growth hormone gene. The growth kinetics of G32, a clonal isolate, were found to be similar to both the parent myeloma and hybridomas. However, production of hGH by G32 was growth associated, rather than as a secondary metabolite as is the case for hybridomas. In addition, G32 produced hGH at molar levels greater than most hybridomas.


Asunto(s)
Hormona del Crecimiento/genética , Proteínas Recombinantes/genética , Transfección , Células Tumorales Cultivadas , Animales , División Celular , Glucosa/metabolismo , Hormona del Crecimiento/biosíntesis , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas Ligeras de Inmunoglobulina/genética , Cinética , Lactatos/metabolismo , Ratones , Regiones Promotoras Genéticas , Proteínas Recombinantes/biosíntesis
18.
Parasite Immunol ; 9(5): 615-26, 1987 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-3684328

RESUMEN

The proteins and antigens of different life stages of Trichostrongylus colubriformis were compared with those of Ostertagia circumcincta in an attempt to identify the subset of parasite molecules that is genus-specific and that may therefore be involved in the induction of genus-specific, host-protective immunity. Novel short-term culture techniques were instituted to label biosynthetically the proteins of the infective larval and adult stages of the parasites using 35S-methionine. High resolution, two-dimensional electrophoretic profiles of the labelled proteins indicated that the majority of proteins synthesized by adults were also present in the larval stages. Qualitative differences in the levels of these common proteins were observed, indicating differences in protein expression or turnover. There was extensive homology between larvae from the different species, with only eight major differences apparent in their profiles of biosynthetically-labelled proteins. Western blot analysis using immune sheep sera indicated that extensive homology also existed between the antigens of T. colubriformis and O. circumcincta larvae.


Asunto(s)
Antígenos Helmínticos/análisis , Ostertagia/inmunología , Proteínas/análisis , Trichostrongylus/inmunología , Animales , Reacciones Cruzadas , Electroforesis en Gel de Poliacrilamida , Inmunoensayo , Marcaje Isotópico , Larva/inmunología , Ostertagia/análisis , Especificidad de la Especie , Trichostrongylus/análisis
19.
Cell ; 45(2): 269-80, 1986 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-2421919

RESUMEN

Evidence is presented that the IIb-IIIa glycoprotein complex, which functions as the receptor for fibrinogen on platelets and is central to platelet aggregation, is expressed on the surface of leukocytes where it may function as a receptor for fibronectin. F(ab')2 fragments of a monoclonal antibody, 25E11, raised against activated large granular lymphocytes, inhibited killing by natural killer cells, blocked the binding of fibronectin-coated particles by monocytes, and stimulated neutrophils to exhibit increased antibody-dependent killing. Immunoprecipitation studies of leukocytes and platelets, and the ability of 25E11 to inhibit platelet aggregation, identified the antigen as an epitope on the IIb-IIIa complex. This glycoprotein thus constitutes the first example of a receptor mediating both platelet aggregation and leukocyte adhesion.


Asunto(s)
Adhesión Celular , Leucocitos/citología , Agregación Plaquetaria , Receptores de Superficie Celular/fisiología , Adulto , Anticuerpos Monoclonales/inmunología , Niño , Citotoxicidad Inmunológica , Epítopos/inmunología , Fibronectinas/metabolismo , Humanos , Fragmentos Fab de Inmunoglobulinas/inmunología , Células Asesinas Naturales/inmunología , Glicoproteínas de Membrana Plaquetaria , Receptores de Fibronectina , Receptores Inmunológicos/metabolismo , Trombastenia/inmunología , Trombastenia/patología
20.
Mol Biochem Parasitol ; 18(3): 333-42, 1986 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3515179

RESUMEN

A cloned library of DNA complementary to the mRNA of adult Schistosoma japonicum has been prepared and expressed as fusion proteins with Escherichia coli beta-galactosidase. Colonies expressing the S. japonicum cDNA clones were screened both with antibodies from individuals with a history of schistosomiasis and with antibodies obtained from a rabbit immunized with whole adult worms. In both cases colonies were detected which bound antibody, although the frequency of antigen-positive clones was much higher with the rabbit antiserum than with human sera. In both cases the proportion of colonies reacting with antibodies was markedly lower than that published for equivalent screens of Plasmodium falciparum cDNA with sera from individuals with a history of falciparum malaria. Several major S. japonicum antigens were identified by the affinity purification of antibodies using immobilised fusion proteins produced during lytic growth of the recombinant bacteriophage.


Asunto(s)
Antígenos Helmínticos/genética , Proteínas Recombinantes/genética , Schistosoma japonicum/inmunología , Anticuerpos/aislamiento & purificación , Cromatografía de Afinidad , Clonación Molecular , ADN/genética , Escherichia coli/genética , Regulación de la Expresión Génica , Vectores Genéticos , Schistosoma japonicum/genética
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