Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Am J Public Health ; 104(11): 2103-13, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25211758

RESUMEN

OBJECTIVES: We explored differences in health and education outcomes between children living in social housing and not, and effects of social housing's neighborhood socioeconomic status. METHODS: In this cohort study, we used the population-based repository of administrative data at the Manitoba Centre for Health Policy. We included children aged 0 to 19 years in Winnipeg, Manitoba, in fiscal years 2006-2007 to 2008-2009 (n = 13,238 social housing; n = 174,017 others). We examined 5 outcomes: age-2 complete immunization, a school-readiness measure, adolescent pregnancy (ages 15-19 years), grade-9 completion, and high-school completion. Logistic regression and generalized estimating equation modeling generated rates. We derived neighborhood income quintiles (Q1 lowest, Q5 highest) from average household income census data. RESULTS: Children in social housing fared worse than comparative children within each neighborhood income quintile. When we compared children in social housing by quintile, preschool indicators (immunization and school readiness) were similar, but adolescent outcomes (grade-9 and high-school completion, adolescent pregnancy) were better in Q3 to Q5. CONCLUSIONS: Children in social housing had poorer health and education outcomes than all others, but living in social housing in wealthier areas was associated with better adolescent outcomes.


Asunto(s)
Escolaridad , Estado de Salud , Vivienda Popular , Características de la Residencia , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Manitoba/epidemiología , Evaluación de Procesos y Resultados en Atención de Salud , Vivienda Popular/estadística & datos numéricos , Características de la Residencia/estadística & datos numéricos , Factores Socioeconómicos , Adulto Joven
2.
Front Psychol ; 12: 733173, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34712180

RESUMEN

In this paper, we describe the model for faculty diversity developed as part of the Professorial Advancement Initiative (PAI) funded under the NSF AGEP program. The PAI, consisting of 12 of the 14 Big Ten Academic Alliance universities, had the goal of doubling the rate at which the universities hired tenure-track minoritized faculty, defined by National Science Foundation as African Americans, Hispanic/Latinx, Native Americans, and Pacific Islanders. This paper reviews the key programmatic elements of the PAI and discusses lessons learned and the practices developed that helped the Alliance achieve its faculty diversity goal.

4.
IEEE Trans Image Process ; 18(8): 1717-23, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19423446

RESUMEN

Subband decompositions for image coding have been explored extensively over the last few decades. The condensed wavelet packet (CWP) transform is one such decomposition that was recently shown to have coding performance advantages over conventional decompositions. A special feature of the CWP is that its design and implementation are performed in the cyclic frequency domain. While performance gains have been reported, efficient implementations of the CWP (or more generally, efficient implementations of cyclic filter banks) have not yet been fully explored. In this paper, we present efficient block-based implementations of cyclic filter banks along with an analysis of the arithmetic complexity. Block-based cyclic filter bank implementations of the CWP coder are compared with conventional subband/wavelet image coders whose filter banks are implemented in the time domain. It is shown that block-based cyclic filter bank implementations can result in CWP coding systems that outperform the popular image coding systems both in terms of arithmetic complexity and coding performance.

5.
IEEE Trans Med Imaging ; 27(3): 370-7, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18334432

RESUMEN

A new technique is presented for interpolating between grey-scale images in a medical data set. Registration between neighboring slices is achieved with a modified control grid interpolation algorithm that selectively accepts displacement field updates in a manner optimized for performance. A cubic interpolator is then applied to pixel intensities correlated by the displacement fields. Special considerations are made for efficiency, interpolation quality, and compression in the implementation of the algorithm. Experimental results show that the new method achieves good quality, while offering dramatic improvement in efficiency relative to the best competing method.


Asunto(s)
Algoritmos , Inteligencia Artificial , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Técnica de Sustracción , Aumento de la Imagen/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
6.
IEEE Trans Image Process ; 17(2): 177-89, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18270110

RESUMEN

In subband/wavelet image coding, size-limited subband decompositions are ordinarily used to avoid increasing the number of samples that need to be coded. To reduce coding distortions that can occur at the borders, the symmetric extension filter bank is typically employed. This paper introduces some new perspectives and improvements to that decomposition. The symmetric extension filter bank is couched in the cyclic frequency domain, providing a framework that accommodates FIR and IIR filters in a natural way, all with perfect reconstruction. IIR filters with both rational and irrational transfer functions can be implemented and, in the context of symmetric extension, can accommodate IIRs that effectively have perfect stopband suppression. Enhancements to the filter bank at a tree-structured system level are also presented and include the application of spectral reversal correction and a transition band normalization approach to designing the constituent filters of the symmetric extension wavelet packet transform.


Asunto(s)
Algoritmos , Gráficos por Computador , Compresión de Datos/métodos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Procesamiento de Señales Asistido por Computador , Análisis Numérico Asistido por Computador , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
7.
Nutr Rev ; 76(9): 708-721, 2018 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-30010929

RESUMEN

Folic acid, a B vitamin, is vital for early neurodevelopment and is well known for its protective effect against neural tube defects. Various national health agencies worldwide recommend that women of childbearing age take approximately 0.4 to 1 mg of supplemental folic acid daily to reduce the risk of neural tube defects in offspring. Several countries have tried to promote folic acid intake through mandatory fortification programs to reduce neural tube defects. Supplementation combined with mandatory fortification of foods has led to high levels of folic acid and related metabolites in women of childbearing age. Recent studies have reported that oversupplementation, defined as exceeding either the recommended dietary allowance or the upper limit of the daily reference intake of folic acid, may have negative effects on human health. This review examines whether maternal oversupplementation with folic acid affects the neurodevelopment of offspring. Data from animal studies suggest there are behavioral, morphological, and molecular changes in the brain of offspring. Additional studies are required to determine both the dosage of folic acid and the timing of folic acid intake needed for optimal neurodevelopment in humans.


Asunto(s)
Suplementos Dietéticos/efectos adversos , Ácido Fólico/efectos adversos , Trastornos del Neurodesarrollo/inducido químicamente , Hipernutrición/etiología , Complicaciones del Embarazo/etiología , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Animales , Femenino , Ácido Fólico/administración & dosificación , Alimentos Fortificados , Humanos , Recién Nacido , Masculino , Defectos del Tubo Neural/prevención & control , Embarazo , Ingesta Diaria Recomendada
8.
J Affect Disord ; 104(1-3): 37-44, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17367867

RESUMEN

BACKGROUND: Depressed patients show mood-congruent errors in the identification of emotion in facial expressions. Errors consist of impaired performance (recognition errors) and negative bias (seeing faces as sadder than they are). This abnormal processing may both reflect and contribute to the negative affective state. In this study, we administered an emotional recognition in facial expression task to women with premenstrual dysphoric disorder (PMDD) to determine whether processing errors similar to those in depression were present and whether they were confined to the luteal phase (i.e., state dependent). METHODS: The Facial Discrimination Task (FDT) was administered in the follicular and luteal phases to women with PMDD (n=28) and asymptomatic controls (n=27). RESULTS: ANOVA with repeated measures identified significantly increased negative judgments (both performance errors and bias) in women with PMDD during the luteal phase (more neutral to sad misjudgments and higher negative bias index) as well as impaired "specificity" of judgments [an inability to discriminate neutral from emotional stimuli] (diagnosis by phase interactions, p<0.05), findings similar to those observed in depression. No menstrual cycle effects were seen in controls, and no differences between patients and controls were seen on a control task (age assessment of pictured subjects). LIMITATIONS: The levels of significance obtained were modest and would not withstand correction for multiple comparisons. CONCLUSION: Women with PMDD display a luteal phase-dependent impairment (negative bias) in the processing of non-verbal affective information. This negative bias may contribute to the generation of negative mood states during the luteal phase and could suggest the presence of dysfunction in those brain regions whose coordinated activity mediates the recognition of emotion in facial expression.


Asunto(s)
Afecto , Discriminación en Psicología , Expresión Facial , Juicio , Ciclo Menstrual/fisiología , Síndrome Premenstrual/psicología , Adulto , Depresión/diagnóstico , Depresión/epidemiología , Depresión/psicología , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Femenino , Fase Folicular/fisiología , Humanos , Fase Luteínica/fisiología , Síndrome Premenstrual/diagnóstico , Síndrome Premenstrual/epidemiología , Pruebas Psicológicas , Reconocimiento en Psicología
9.
Simul Healthc ; 12(6): 356-363, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29210891

RESUMEN

INTRODUCTION: Although recent literature suggests that students should be trained in the care of persons with disability (PWDs) as a form of cultural sensitivity (CS), healthcare professionals may receive limited experience during their formal training. After pharmacy students in 2 previous years of testing failed to adequately assess and plan for the care of a standardized patient's chief complaint and disability in an Objective Structured Clinical Examination (OSCE), the investigators added debriefing to the OSCE to determine if it would improve student's ability to assess and plan for the care of PWD. METHODS: Two sequentially enrolled second-year pharmacy school student cohorts participated in this study (control n = 90; intervention n = 82). During the OSCE, students interviewed and examined a standardized patient with a simulated physical disability and other chronic disease states. Students were then instructed to develop a care plan considering the patient's disability and other disease states. The intervention cohort received debriefing; the control did not. Students documented the care plan in a subjective, objective, assessment, and plan (SOAP) note. Investigators assessed SOAP note score (general ability of students to write a SOAP note) and CS score (specific ability to care for PWD) to determine the effectiveness of the debriefing. RESULTS: The intervention group showed a significantly higher percent mean CS score than the control group (93.6% ± 19% and 61.1% ± 30.7%, respectively, P < 0.001), translating to a mean of 56.2/60 points earned for the intervention group and 36.7/60 points earned for the control group. Scores ranged from 0 to 60 points for both intervention and control groups. Students in the intervention group had an absolute improvement in pass rates (those students scoring ≥70% on the OSCE) of 59.4% with 92.7% of the students passing in the intervention group versus 33.3% of the students passing in the control group (P < 0.001). The overall SOAP note scores were no different between the 2 cohorts (P = 0.353). CONCLUSIONS: Debriefing added to an OSCE improved students' performance in developing care plans for disabled patients. Ideally, longitudinal studies should be completed to determine if these skills transfer from debriefings to clinical practice. Development of effective training and assessment methods is essential for students to obtain adequate skills and knowledge to care for persons with disabilities.


Asunto(s)
Personas con Discapacidad/rehabilitación , Educación en Farmacia/organización & administración , Retroalimentación Formativa , Adulto , Competencia Clínica , Comunicación , Evaluación Educacional , Femenino , Humanos , Masculino , Adulto Joven
10.
Arch Gen Psychiatry ; 62(2): 154-62, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15699292

RESUMEN

CONTEXT: Alternative and over-the-counter medicines have become increasingly popular choices for many patients who prefer not to take traditional antidepressants. The adrenal androgen and neurosteroid dehydroepiandrosterone (DHEA) is available as over-the-counter hormonal therapy and previously has been reported to have antidepressant-like effects. OBJECTIVE: To evaluate the efficacy of DHEA as a monotherapy treatment for midlife-onset depression. DESIGN: A double-blind, randomized, placebo-controlled, crossover treatment study was performed from January 4, 1996, through August 31, 2002. Settings The National Institute of Mental Health Midlife Outpatient Clinic in the National Institutes of Health Clinical Center, Bethesda, Md. Patients Men (n = 23) and women (n = 23) aged 45 to 65 years with midlife-onset major or minor depression participated in this study. None of the subjects received concurrent antidepressant medications. Intervention Six weeks of DHEA therapy, 90 mg/d for 3 weeks and 450 mg/d for 3 weeks, and 6 weeks of placebo. MAIN OUTCOME MEASURES: The 17-Item Hamilton Depression Rating Scale and Center for Epidemiologic Studies Depression Scale. Additional measures included the Derogatis Interview for Sexual Functioning. Results were analyzed by means of repeated-measures analysis of variance and post hoc Bonferroni t tests. RESULTS: Six weeks of DHEA administration was associated with a significant improvement in the 17-Item Hamilton Depression Rating Scale and the Center for Epidemiologic Studies Depression Scale ratings compared with both baseline (P<.01) and 6 weeks of placebo treatment (P<.01). A 50% or greater reduction in baseline Hamilton Depression Rating Scale scores was observed in 23 subjects after DHEA and in 13 subjects after placebo treatments. Six weeks of DHEA treatment also was associated with significant improvements in Derogatis Interview for Sexual Functioning scores relative to baseline and placebo conditions. CONCLUSION: We find DHEA to be an effective treatment for midlife-onset major and minor depression.


Asunto(s)
Deshidroepiandrosterona/uso terapéutico , Trastorno Depresivo Mayor/tratamiento farmacológico , Trastorno Depresivo/tratamiento farmacológico , Anciano , Atención Ambulatoria , Estudios Cruzados , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/psicología , Trastorno Depresivo Mayor/diagnóstico , Trastorno Depresivo Mayor/psicología , Método Doble Ciego , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inventario de Personalidad , Placebos , Escalas de Valoración Psiquiátrica , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
11.
Biol Psychiatry ; 54(7): 757-62, 2003 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-14512217

RESUMEN

BACKGROUND: Premenstrual syndrome (PMS) involves an aberrant behavioral response to normal hormone secretion. Pathogenetic theories posit abnormal modulation of gamma-aminobutyric acid (GABA) transmission in the brain by neuroactive metabolites of progesterone (neurosteroids). In earlier transcranial magnetic stimulation (TMS) studies of the motor cortex, we showed that inhibition increases in the luteal phase, consistent with neurosteroid action at the GABA(A) receptor. Here, we studied women with PMS to see if their response to endogenous progesterone differed from that of control subjects. METHODS: We studied nine women with PMS and 14 control subjects during the midfollicular and luteal phases with paired TMS. Subthreshold conditioning TMS was followed by test stimulation that produced a motor evoked potential (MEP) in a hand muscle. We gave pairs at each of seven intervals (2-10 msec) and unconditioned stimuli, measuring the amplitude ratio of the average MEP from the pairs at each interval to that from the unconditioned stimuli (ratio < 1 = inhibition). RESULTS: Both groups showed the same follicular phase response to paired TMS. Control subjects showed more inhibition in the luteal phase. Women with PMS showed relative facilitation. CONCLUSIONS: This is the first physiological evidence for an abnormal brain response to progesterone in PMS.


Asunto(s)
Potenciales Evocados Motores/fisiología , Fase Folicular/fisiología , Fase Luteínica/fisiología , Corteza Motora/fisiopatología , Síndrome Premenstrual/fisiopatología , Adulto , Análisis de Varianza , Estudios de Casos y Controles , Condicionamiento Clásico , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Umbral Diferencial , Estradiol/análisis , Femenino , Humanos , Progesterona/análisis , Factores de Tiempo
12.
Am J Psychiatry ; 159(11): 1876-81, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12411222

RESUMEN

OBJECTIVE: The authors investigated the role of acute serotonergic modulation in the efficacy of selective serotonin reuptake inhibitors (SSRIs) in women with premenstrual dysphoric disorder. METHOD: Patients with premenstrual dysphoric disorder (whose symptoms had remitted during treatment with fluoxetine) and a group of unmedicated healthy comparison women received the serotonin receptor antagonist metergoline as part of a double-blind, placebo-controlled crossover study. RESULTS: The patients with premenstrual dysphoric disorder experienced a return of symptoms 24 hours after treatment with metergoline but not diphenhydramine (active placebo). The comparison women experienced no changes in mood. CONCLUSIONS: These data support the role of altered serotonergic transmission in the efficacy of SSRI treatment for premenstrual dysphoric disorder.


Asunto(s)
Depresión/fisiopatología , Metergolina , Síndrome Premenstrual/fisiopatología , Receptores de Serotonina/fisiología , Antagonistas de la Serotonina , Adulto , Afecto/efectos de los fármacos , Afecto/fisiología , Depresión/diagnóstico , Depresión/tratamiento farmacológico , Depresión/psicología , Difenhidramina/efectos adversos , Difenhidramina/uso terapéutico , Método Doble Ciego , Femenino , Fluoxetina/efectos adversos , Fluoxetina/uso terapéutico , Humanos , Inventario de Personalidad , Síndrome Premenstrual/diagnóstico , Síndrome Premenstrual/tratamiento farmacológico , Síndrome Premenstrual/psicología , Receptores de Serotonina/efectos de los fármacos , Inhibidores Selectivos de la Recaptación de Serotonina/efectos adversos , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Resultado del Tratamiento
13.
J Psychiatr Res ; 37(1): 75-83, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12482472

RESUMEN

While diagnostic criteria for premenstrual syndromes (PMS) exist, studies rarely state how these criteria are operationally applied. We examined the consequences of application of different operational methods for DSM-IV criteria for premenstrual dysphoric disorder (PMDD) to individual cycles in women with PMS and controls. PMDD criteria require the presence of both certain types or numbers of symptoms (5/11 symptoms present premenstrually, at least one being one of four mood symptoms) and certain phenomenal characteristics (present premenstrually, absent postmenstrually, causing interference premenstrually). We identified individual cycles as symptomatic or asymptomatic by applying criteria that operationalized the required phenomenal elements of PMDD according to four severity thresholds: literal (i.e. present or absent), 30%, 50%, 70%. Data examined were Daily Rating Form symptom scores from two symptomatic menstrual cycles both in 25 women with PMS and 25 controls. Literal thresholds correctly identified 28% of symptomatic and 4% of asymptomatic cycles, compared with 86 and 70% identification with a 30% threshold, 60 and 86% with a 50% threshold, and 0 and 100% with a 70% threshold. An "optimal" combination of 30% thresholds for premenstrual symptomatology and premenstrual interference and a 50% threshold for postmenstrual symptomatology correctly identified 92% of symptomatic cycles in women with PMS and 72% of asymptomatic cycles in controls. Different criteria for cycle inclusion yield markedly different sample compositions. No single operational threshold of the phenomenal features maximizes selection of both symptomatic and asymptomatic cycles, largely consequent to the ubiquity of postmenstrual symptoms and premenstrual "interference" even in women without PMS. At the very least, the method for operationalizing DSM-IV criteria should be described in studies of PMDD.


Asunto(s)
Ciclo Menstrual/psicología , Síndrome Premenstrual/diagnóstico , Adulto , Diagnóstico Diferencial , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Femenino , Humanos , Síndrome Premenstrual/clasificación , Prevalencia , Estudios Prospectivos , Escalas de Valoración Psiquiátrica , Psicometría , Índice de Severidad de la Enfermedad
14.
Inorg Chem ; 35(9): 2611-2615, 1996 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-11666476

RESUMEN

The reactions of Ga(CH(2)CH(3))(3) with variable amounts of elemental sulfur, S(8), in toluene or benzene at different temperatures result in the insertion of sulfur into the Ga-C bonds to form the compounds Ga[(S-S)CH(2)CH(3)](3) (I) and Ga[(S-S-S)CH(2)CH(3)](3) (II). Compound I was isolated from the reaction at low temperature while at room temperature; compound II was the major product. Compound II exhibited the maximum extent of sulfur insertion even when the reactions were carried out with more than 9.0 equiv of sulfur. The reactions of Ga(CH(3))(3) with various amounts of sulfur in toluene or benzene only result in the formation of compound III, Ga[(S-S)CH(3)](3). In pyridine at -30 degrees C, deinsertion of the sulfur atoms from Ga-S-S-C bonds was observed for the first time from compounds I and III resulting in formation of the six-membered Ga-S ring compounds IV, [PyEtGaS](3), and V, [PyMeGaS](3), respectively. Compounds IV and V were characterized by (1)H NMR, (13)C NMR, elemental analyses, thermogravimetric analysis, and single-crystal X-ray diffraction. Compound IV crystallized in the monoclinic space group P2(1)/n, with a = 9.288(2) Å, b = 14.966(2) Å, c = 19.588(3) Å, beta = 90.690(10) degrees, and Z = 4. Compound V crystallized in the monoclinic space group P2(1)/c, with a = 10.385(1) Å, b = 15.300(2) Å, c = 15.949(2) Å, beta = 107.01(1) degrees, Z = 4, unit cell volume = 2423.5(5) Å(3), R = 0.030, and R(w) = 0.026. The sulfur insertion reaction pathway was investigated by time-dependent and variable-temperature (1)H NMR spectroscopy.

15.
Inorg Chem ; 35(24): 6995-7000, 1996 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-11666878

RESUMEN

The synthesis, characterization, and reactivity of new polyether adducts of strontium and barium carboxylates of general composition M(O(2)CCF(3))(n)()(L) (M = Ba, L = 15-crown-5, (1); M = Ba (2), Sr (3), respectively, with L = tetraglyme are reported. The compounds were synthesized by reaction of BaCO(3) or MH(2) (M = Sr or Ba) with organic acids in the presence of the polyether ligands. These compounds have been characterized by IR and (13)C and (1)H NMR spectroscopies, elemental analyses, and thermogravimetric analysis. The species Ba(2)(O(2)CCF(3))(4)(15-crown-5)(2) (1) and [Ba(2)(O(2)CCF(3))(4)(tetraglyme)](infinity) (2), were also characterized by single-crystal X-ray diffraction. Ba(2)(O(2)CCF(3))(4)(15-crown-5)(2) (1) crystallizes in the orthorhombic space group Cccm with cell dimensions of a = 13.949(1) Å, b = 19.376(2) Å, c = 16.029(1) Å, and Z = 8. [Ba(2)(O(2)CCF(3))(4)(tetraglyme)](infinity) (2) crystallizes in the monoclinic space group C2/c with cell dimensions of a = 12.8673(12) Å, b = 16.6981(13) Å, c = 15.1191(12) Å, beta = 99.049(8) degrees, and Z = 4. Compounds 1-3 thermally decompose at high temperatures in the solid state to give MF(2). However, solutions of compounds 1-3 dissolved in ethanol with Ti(O-i-Pr)(4) give crystalline perovskite phase MTiO(3) films, or in the case of mixtures of 2 and 3, Ba(1)(-)(x)()Sr(x)()TiO(3) films below 600 degrees C when spin coated onto silicon substrates and thermally treated. The crystallinity, purity, and elemental composition of the films was determined by glancing angle X-ray diffraction and Auger electron spectroscopy.

16.
Inorg Chem ; 36(10): 2218-2224, 1997 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-11669848

RESUMEN

A series of group 12 metal thiocarboxylate species, M(SOCR)(2)Lut(2) [M = Cd, Zn; R = CH(3), C(CH(3))(3); Lut = 3,5-dimethylpyridine (lutidine)], were synthesized to investigate their potential to act as precursors for the formation of metal sulfide materials. These species were expected to undergo thiocarboxylic anhydride elimination to give stoichiometric metal sulfides and remove the organic supporting ligands cleanly. These species were characterized by (1)H, (13)C, and (where appropriate) (113)Cd NMR spectroscopies, TGA, elemental analysis, and single-crystal X-ray diffraction. The spectroscopic and analytical data were consistent with the formulas identified above, and in the solid state the compounds are monomeric with approximate tetrahedral metal coordination environments and monodentate S-bond thiocarboxylate ligands. Crystal data for Cd(SOCCH(3))(2)Lut(2): crystallized in the triclinic space group P&onemacr;, with a = 8.267(1) Å, b = 9.467(1) Å, c = 14.087(1) Å, alpha = 94.04(1) degrees, beta = 91.49(1) degrees, gamma = 104.03(1) degrees, and Z = 2. Thermal decomposition of these compounds in the solid state or in solution resulted in formation of the corresponding metal sulfide at low temperatures, as seen by powder X-ray diffraction. Evidence for thiocarboxylic anhydride elimination was documented by NMR in solution phase reactions. The effects on thiocarboxylic anhydride elimination, resulting from varying M, R, or solvent media, were examined by heating NMR tube solutions of M(SOCR)(2)Lut(2) in pyridine or toluene. Heating toluene or pyridine solutions of Cd(SOCCH(3))(2)Lut(2) resulted in formation of nanocrystalline, sphalerite CdS, as determined by X-ray diffraction and TEM. These preliminary reactivity studies have revealed the great potential of this highly tailorable chemical system as precursors to group 12 metal sulfido species.

17.
IEEE Trans Biomed Eng ; 50(2): 197-206, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12665033

RESUMEN

The problem of interslice magnetic resonance (MR) image reconstruction arises in a broad range of medical applications. In such cases, there is a need to approximate information present in the original subject that is not reflected in contiguously acquired MR images because of hardware sampling limitations. In the context of vascular morphology reconstruction, this information is required in order for subsequent visualization and computational analysis of blood vessels to be most effective. Toward that end we have developed a method of vascular morphology reconstruction based on adaptive control grid interpolation (ACGI) to function as a precursor to visualization and computational analysis. ACGI has previously been implemented in addressing various problems including video coding and tracking. This paper focuses on the novel application of the technique to medical image processing. ACGI combines features of optical flow-based and block-based motion estimation algorithms to enhance insufficiently dense MR data sets accurately with a minimal degree of computational complexity. The resulting enhanced data sets describe vascular geometries. These reconstructions can then be used as visualization tools and in conjunction with computational fluid dynamics (CFD) simulations to offer the pressure and velocity information necessary to quantify power loss. The proposed ACGI methodology is envisioned ultimately to play a role in surgical planning aimed at producing optimal vascular configurations for successful surgical outcomes.


Asunto(s)
Algoritmos , Vasos Sanguíneos/anatomía & histología , Procedimiento de Fontan/métodos , Aumento de la Imagen/métodos , Imagenología Tridimensional/métodos , Imagen por Resonancia Magnética/métodos , Artefactos , Vasos Sanguíneos/fisiopatología , Retroalimentación , Humanos , Movimiento (Física) , Fantasmas de Imagen , Arteria Pulmonar/anatomía & histología , Arteria Pulmonar/fisiopatología , Procedimientos de Cirugía Plástica/métodos , Tamaño de la Muestra , Procedimientos Quirúrgicos Vasculares/métodos
18.
IEEE Trans Image Process ; 13(11): 1424-31, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15540452

RESUMEN

This paper introduces an improved structure for directional filter banks (DFBs) that preserves the visual information in the subband domain. The new structure achieves this outcome while preserving both the efficient polyphase implementation and the exact reconstruction property. The paper outlines a step-by-step framework in which to examine the DFB, and within this framework discusses how, through the insertion of post-sampling matrices, visual distortions can be removed. In addition to the efficient tree structure, attention is given to the form and design of efficient linear phase filters. Most notably, linear phase IIR prototype filters are presented, together with the design details. These filters can enable the DFB to have more than a three-fold improvement in complexity reduction over quadrature mirror filters (QMFs).


Asunto(s)
Algoritmos , Inteligencia Artificial , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Almacenamiento y Recuperación de la Información/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Procesamiento de Señales Asistido por Computador , Gráficos por Computador , Imagenología Tridimensional/métodos , Análisis Numérico Asistido por Computador , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Técnica de Sustracción
19.
Can J Cardiol ; 29(5): 606-12, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23395221

RESUMEN

BACKGROUND: Hypertension is a substantial health concern because it poses significant risks for cardiovascular morbidity and mortality and is highly prevalent in the population. Tracking hypertension is important because it is a risk factor for other conditions, but prevalence estimates might vary depending on the data source used. METHODS: This report describes 3 national population-based data sources for estimating hypertension prevalence in Canada and discusses their strengths and weaknesses to aid in their use for policy and program planning. They are compared based on: sample coverage, case identification, and prevalence estimates. RESULTS: Each source produces a different measure of hypertension prevalence, as follows: (1) diagnosed hypertension from the Canadian Chronic Disease Surveillance System (CCDSS) (2007/2008); (2) self-reported diagnosed hypertension from the Canadian Community Health Survey (CCHS) (2007-2008); and, (3) physically-measured hypertension from the Canadian Health Measures Survey (CHMS) (2007-2009). Crude rates and counts of hypertension prevalence among individuals aged 20 to 79 years of age, excluding pregnant women, are compared, resulting in prevalence ranging from 18.2% in self-report data to 20.3% in diagnosed data. The data sources differ in terms of target population, case identification, and limitations, which affects the estimates. CONCLUSIONS: Each source has unique strengths and is best suited for addressing particular research questions. For example, diagnosed hypertension can be used to determine health care utilization patterns, self-reported to examine health determinants, and measured high blood pressure to improve awareness, treatment, and control. Combined, they can address multiple issues and increase our knowledge of hypertension in Canada.


Asunto(s)
Técnicas y Procedimientos Diagnósticos , Encuestas Epidemiológicas , Hipertensión/diagnóstico , Adulto , Anciano , Canadá/epidemiología , Femenino , Humanos , Hipertensión/epidemiología , Masculino , Persona de Mediana Edad , Embarazo , Prevalencia , Vigilancia en Salud Pública , Autoinforme , Adulto Joven
20.
IEEE Trans Image Process ; 20(11): 3063-72, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22010123

RESUMEN

Two-band analysis-synthesis filters or wavelet filters are used pervasively for compressing natural images. Both FIR and IIR filters have been studied in this context, the former being the most popular. In this paper, we examine the compression performance of these two-band filters in a dyadic wavelet decomposition and attempt to isolate features that contribute most directly to the performance gain. Then, employing the general exact reconstruction condition, hybrid FIR-IIR analysis-synthesis filters are designed to maximize compression performance for natural images. Experimental results are presented that compare performance with the popular biorthogonal filters in terms of peak SNR, subjective quality, and computational complexity.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA