1,833 research outputs found
Face recognition system using fringe projection and moiré: characterization with fractal parameters
We show a new method for face recognition which combines the projection of structures with different characteristics (fringes, bars or grids, dots or speckle) over the face. These projections will then allow the creation of a computer-generated moiré pattern over which different kinds of fractal and complex geometry parameters are then measured. Such parameters will then be used as inputs for a neuro-symbolic hybrid system. Here, we analyze the incidence of some parameters on the efficience for the face recognition method
Paramagnetic GaN:Fe and ferromagnetic (Ga,Fe)N - relation between structural, electronic, and magnetic properties
We report on the metalorganic chemical vapor deposition (MOCVD) of GaN:Fe and
(Ga,Fe)N layers on c-sapphire substrates and their thorough characterization
via high-resolution x-ray diffraction (HRXRD), transmission electron microscopy
(TEM), spatially-resolved energy dispersive X-ray spectroscopy (EDS),
secondary-ion mass spectroscopy (SIMS), photoluminescence (PL), Hall-effect,
electron-paramagnetic resonance (EPR), and magnetometry employing a
superconducting quantum interference device (SQUID). A combination of TEM and
EDS reveals the presence of coherent nanocrystals presumably FexN with the
composition and lattice parameter imposed by the host. From both TEM and SIMS
studies, it is stated that the density of nanocrystals and, thus the Fe
concentration increases towards the surface. In layers with iron content x<0.4%
the presence of ferromagnetic signatures, such as magnetization hysteresis and
spontaneous magnetization, have been detected. We link the presence of
ferromagnetic signatures to the formation of Fe-rich nanocrystals, as evidenced
by TEM and EDS studies. This interpretation is supported by magnetization
measurements after cooling in- and without an external magnetic field, pointing
to superparamagnetic properties of the system. It is argued that the high
temperature ferromagnetic response due to spinodal decomposition into regions
with small and large concentration of the magnetic component is a generic
property of diluted magnetic semiconductors and diluted magnetic oxides showing
high apparent Curie temperature.Comment: 21 pages, 30 figures, submitted to Phys. Rev.
Limited tumor infiltration by activated T effector cells restricts the therapeutic activity of regulatory T cell depletion against established melanoma
Interference with inhibitory immunological checkpoints controlling T cell activation provides new opportunities to augment cancer immunotherapies. Whereas cytotoxic T lymphocyte–associated antigen-4 blockade has shown promising preclinical and clinical results, therapeutic CD4+CD25+ T reg cell depletion has failed to consistently enhance immune-based therapies. Using B16/BL6, a transplantable murine melanoma model, we show a dichotomy between the effects of T reg cell depletion on tumor rejection dependent on whether depletion occurs before (prophylactic) or after (therapeutic) tumor engraftment. Failure to promote rejection with therapeutic depletion is not related to lack of T reg cell depletion, to elimination of CD25+ effector T cells, or to a failure to enhance systemic antitumor T cell responses, but correlates with failure of effector cells to infiltrate the tumor and increase the intratumor ratio of effector T cell/T reg cell. Finally, systemic antitumor responses generated upon therapeutic T reg cell depletion are significantly stronger than those generated in the presence of T reg cells, and are capable of eliciting rejection of established tumors after transfer into immunoablated recipients receiving combination immunotherapy. The data demonstrate a dissociation between measurable systemic responses and tumor rejection during CD25-directed T reg cell depletion, and suggest an alternative, clinically applicable strategy for the treatment of established tumors
Novel, bilateral, two-bellied muscles span the extensor forearm, thenar eminence to insert on the proximal phalanx of the thumb: clinical and embryological significance
Muscle and tendon variations in the forearm, wrist and hand are commonly reported in the anatomical and surgical literature. They are frequently the source of inflammatory conditions such as de Quervain’s tenosynovitis or carpal tunnel syndrome. During academic dissection, a cadaver presented with bilateral, additional muscles running parallel to the abductor pollicis longus muscles (APL) in the extensor compartment of the forearm. Both additional muscles had two bellies, one proximal and one distal, with an intervening tendon. The proximal bellies were separate and distinct from the adjacent APLs. The tendons traversed the first dorsal compartments with the tendons of the APLs and the extensor pollicis brevis muscles (EPB). The distal bellies lay adjacent to the abductor pollicis brevis (APB) muscles in the thenar compartments, and inserted onto the volar base of the proximal phalanges of the thumbs. Following a thorough search of the literature, we determined that these additional muscles constitute a previously unreported variation. This report details the variation, compares it with other reported variations, presents the related embryology, and reviews the significance of this variation as it relates to inflammatory conditions and surgical procedures
Obesity by BMI and central obesity in adolescents from Comodoro Rivadavia, Patagonia Argentina
Antecedentes: La prevalencia de obesidad infantil y adolescente resulta relevante ya que con frecuencia el sobrepeso a esa edad persistirá en la vida adulta. Objetivo: Determinar sobrepeso y obesidad en una población adolescente de Comodoro Rivadavia, Patagonia Argentina. Métodos: Se utilizaron las tablas propuestas para el índice de masa corporal (IMC) y la circunferencia de cintura (CC) por los siguientes tres grupos: International Obesity Taskforce (IOTF), Centers for Disease Control and Prevention (CDC) y la Organización Mundial de la Salud (OMS). Se evaluó el grado de concordancia en las definiciones, en relación a las tablas empleadas. Se estudiaron por muestreo no probabilístico y consecutivo, 402 voluntarios (279 mujeres y 123 varones) de edades comprendidas entre 12 y 16 ± 0,5 años. Con consentimiento escrito de los padres y asentimiento de los voluntarios, se midió peso, talla presión arterial y CC. Se calcularon percentiles del IMC y de la CC. Resultados: Al utilizar tanto las tablas IOTF como CDC más del 40 % de la población presentó sobrepeso u obesidad según el IMC. No se evidenciaron diferencias estadísticamente significativas al evaluar sobrepeso según sexo mientras que los varones presentaron mayores índices de obesidad con ambas definiciones (p0,05). Conclusiones: La prevalencia de obesidad es elevada tanto al considerar percentiles tanto de IMC, como de CC. El grado de acuerdo de las definiciones es adecuado. Estos resultados aportan información regional inexistente hasta este momento y alertan sobre una situación que requiere una urgente intervención sanitaria.Background: The prevalence of overweight and obesity in childhood and adolescence is important because it will frequently persist in adult life. Objective: To determine overweight and obesity in a group of adolescents from Comodoro Rivadavia, Argentine Patagonia through the use of body mass index (BMI) and waist circumference. Methods: Obesity Taskforce (IOTF), Centers for Disease Control and Prevention (CDC) and Word Health Organization (WHO) tables were used. The agreement degree in the definitions was evaluated in relation with the tables used. 402 volunteers were studied, aged between 12 to 16 years old ± 0.5. Written parental consent and assent of volunteers were obtained. Anthropometry, blood pressure were measured, andbody mass index and waist circumference´s percentile (Pc) were calculated. Results: Over 40 % of the adolescents were obese or overweight (BMI equal or major 95 or 85, respectively). There weren´t significant statistic difference between overweight and gender while the males showed majors obesity index with both definitions (p0.05). Conclusions: The prevalence of obesity is high with both BMI, as waist circumference percentiles. The degree agreement of the definition is adequate. These results contribute regional information that actually it is non-existent up to now and it alert about a situation that requires an urgent sanitary intervention.Fil: Ponce, Graciela M.. Universidad Nacional de la Patagonia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Quezada, Andrés O.. Universidad Nacional de la Patagonia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodríguez, María A. Universidad Nacional de la Patagonia; ArgentinaFil: Boeri, Mónica P.. Universidad Nacional de la Patagonia; ArgentinaFil: Soto, Mariana S.. Universidad Nacional de la Patagonia; ArgentinaFil: Brites, Fernando Daniel. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Genetic analysis of porcine circovirus type 2 from pigs affected with PMWS in Chile reveals intergenotypic recombination
Background: Porcine circovirus type 2 (PCV2) is a very small, non-enveloped and icosahedral virus, with circular single stranded DNA genome. This virus is the most ubiquitous and persistent pathogen currently affecting the swine industry worldwide. PCV2 has been implicated as the major causative agent of postweaning multisystemic wasting syndrome (PMWS), a disease which is characterized by severe immunosuppressive effects in the porcine host. Worldwide PCV2 isolates have been classified into four different genotypes, PCV2a, PCV2b, PCV2c and PCVd. The goal of this work was to conduct the first phylogenetic analysis of PCV2 in Chile. Methods: PCV2 partial ORF2 sequences (462 nt) obtained from 29 clinical cases of PMWS in 22 Chilean intensive swine farms, covering over the 90% of the local pork-production, were analyzed. Results: 14% and 52% of sequences belonged to the genotypes PCV2a and PCV2b, respectively. Surprisingly, 34% of sequences were PCV2a/PCV2d recombinant viruses. Conclusions: Our findings suggested that a novel cluster of Chilean sequences emerged resulting from intergenotypic recombination between PCV2a and PCV2d
Patient-initiated second medical consultations: patient characteristics and motivating factors, impact on care and satisfaction: A systematic review
Objectives: To review the characteristics and motivations of patients seeking second opinions, and the impact of such opinions on patient management, satisfaction, and cost-effectiveness. Data sources: Embase, Medline, PsycINFO and HMIC databases. Study design: A systematic literature search was performed for terms related to second opinion and patient characteristics. Study quality was assessed using the National Institutes of Health (NIH) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Data collection / Extraction methods: We included articles focused on patient-initiated second opinions, which provided quantitative data on their impact on diagnosis, treatment, prognosis or patient satisfaction, described the characteristics or motivating factors of patients who initiated a second opinion, or the cost-effectiveness of patient-initiated second opinions. Principal findings: Thirty-one articles were included in the review. 27 studies considered patient characteristics, 18 patient motivating factors, 10 patient satisfaction, and 17 clinical agreement between the first and second opinion. Seeking a second opinion was more common in women, middle age patients, more educated patients; and in people having a chronic condition, with higher income or socioeconomic status or living in central urban areas. Patients seeking a second opinion sought to gain more information or reassurance about their diagnosis or treatment. While many second opinions confirm the original diagnosis or treatment, discrepancies in opinions had a potential major impact on patient outcomes in up to 58% of cases. No studies reporting on the cost-effectiveness of patient initiated second opinions. Conclusions: Seeking a second opinion was more common in women, middle-age patients, and more educated patients, and in people having a chronic condition, with higher income or socioeconomic status or living in central urban areas. Patients seeking a second opinion sought to gain more information or reassurance about their diagnosis or treatment
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