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1.
Skin Res Technol ; 24(2): 256-264, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29057507

RESUMEN

BACKGROUND: Basal cell carcinoma (BCC) is the most common skin cancer, which is highly damaging in its advanced stages. Computer-aided techniques provide a feasible option for early detection of BCC. However, automated BCC detection techniques immensely rely on handcrafting high-level precise features. Such features are not only computationally complex to design but can also represent a very limited aspect of the lesion characteristics. This paper proposes an automated BCC detection technique that directly learns the features from image data, eliminating the need for handcrafted feature design. METHODS: The proposed method is composed of 2 parts. First, an unsupervised feature learning framework is proposed which attempts to learn hidden characteristics of the data including vascular patterns directly from the images. This is done through the design of a sparse autoencoder (SAE). After the unsupervised learning, we treat each of the learned kernel weights of the SAE as a filter. Convolving each filter with the lesion image yields a feature map. Feature maps are condensed to reduce the dimensionality and are further integrated with patient profile information. The overall features are then fed into a softmax classifier for BCC classification. RESULTS: On a set of 1199 BCC images, the proposed framework achieved an area under the curve of 91.1%, while the visualization of learned features confirmed meaningful clinical interpretation of the features. CONCLUSION: The proposed framework provides a non-invasive fast BCC detection tool that incorporates both dermoscopic lesional features and clinical patient information, without the need for complex handcrafted feature extraction.


Asunto(s)
Carcinoma Basocelular/patología , Neoplasias Cutáneas/patología , Dermoscopía/métodos , Diagnóstico por Computador/métodos , Detección Precoz del Cáncer , Humanos , Examen Físico
2.
Haemophilia ; 23(3): 466-475, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28205396

RESUMEN

BACKGROUND: Thrombin generation test (TGT) is a global haemostasis assay with a potential to predict bleeding tendencies and treatment effects in patients with haemophilia. Despite 15 years of clinical research, the diagnostic value of TGT remains controversial, possibly due to suboptimal sensitivity to coagulation deficiencies, robustness and reproducibility. OBJECTIVE: The goal of this study was to explore the effect of calcium chloride (CaCl2 ) concentration on the TGT's response to intrinsic coagulation factors (F) VIII, IX and XIa. METHODS: Normal and factor-deficient plasmas supplemented with lacking coagulation factor and different CaCl2 levels were tested by calibrated thrombinography assay. RESULTS: Thrombin peak height (TPH) was strongly CaCl2 dependent, increasing sharply from no TG at 5 mm to a peak at 13.8 mm of CaCl2 (95% confidence interval [CI]: 13.0, 14.5) in normal and normalized deficient plasmas and at 11.9 mm (CI: 9.7, 14.2) in deficient plasmas, and then decreasing slowly to a complete inhibition at 30-40 mm. In contrast, TG lag time, time to peak and endogenous thrombin potential were nearly insensitive to CaCl2 concentrations between 10 and 20 mm. The maximal difference between the TPH in deficient and supplemented plasmas was observed at 15.5 mm (CI: 12.8, 18.1). CONCLUSION: Variations in CaCl2 concentration in the assay mixture and sodium citrate concentrations in patient plasma samples may affect TGT responses, sensitivity and result in increased inter- and intra-laboratory variance. Implementation of TGT by clinical and quality control laboratories may require optimization of CaCl2 concentration.


Asunto(s)
Análisis Químico de la Sangre/métodos , Cloruro de Calcio/farmacología , Hemorragia/diagnóstico , Hemostasis/efectos de los fármacos , Trombina/biosíntesis , Relación Dosis-Respuesta a Droga , Hemofilia A/complicaciones , Hemorragia/sangre , Hemorragia/complicaciones , Trombina/metabolismo , Tromboplastina/metabolismo
8.
Arch Dermatol Res ; 315(3): 541-550, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36173455

RESUMEN

The epidemiology of vitiligo, especially its disease burden on the healthcare system, can be assessed indirectly by analyzing health insurance claims data. Validating this approach is integral to ensuring accurate case identification and cohort characterization. The primary aim of this study was to develop and validate an indirect measure of vitiligo ascertainment using health insurance claims data. These data were used secondarily to identify demographic characteristics, body site involvement, vitiligo subtypes, disease associations, and treatments. This study assessed the validity of identifying vitiligo from billing claims within a Canadian provincial universal health insurance program, versus vitiligo cases accrued from direct medical chart reviews. Claims-based algorithms combining ICD-9-CM diagnostic code 709 with treatment-specific data were derived and tested to identify vitiligo patients. This was compared against cases arising from the manual review of medical records of 606 patient with a diagnostic code for "dyschromia" (ICD-9-CM diagnostic code 709) from January 1 to December 31, 2016. Based on the chart reviews, 204 (33.7%) patients were confirmed to have vitiligo. 42 separate claims-based algorithms combining ICD-9-CM diagnostic code 709 with treatment data specific to vitiligo were modeled and individually tested to evaluate their accuracy for vitiligo ascertainment. One algorithm achieved a sensitivity, specificity, PPV and NPV of 86.8% (95% CI 82.1-91.4), 92.5% (95% CI 90.0-95.1), 85.5% (95% CI 80.7-90.3), and 93.2% (95% CI 90.8-95.7), respectively. There was a 2.2 female-to-male ratio. The most common medical treatments were tacrolimus (74.5%) and topical corticosteroids (54.3%). Hypertension (24.2%) and hypothyroidism (19.6%) were the predominant co-morbidities associated with vitiligo. Health insurance claims data can be used to indirectly ascertain vitiligo for epidemiologic purposes with relatively high diagnostic performance between 85.5 and 93.2%.


Asunto(s)
Vitíligo , Humanos , Masculino , Femenino , Vitíligo/diagnóstico , Vitíligo/epidemiología , Vitíligo/terapia , Canadá , Algoritmos , Clasificación Internacional de Enfermedades , Revisión de Utilización de Seguros , Bases de Datos Factuales
9.
Acta Virol ; 56(3): 187-98, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23043598

RESUMEN

UNLABELLED: Sweet potato leaf curl disease (SPLCD) was primarily identified in sweet potato fields in Korea in 2003, and the complete genomic sequence of sweet potato leaf curl virus (SPLCV) has been cloned. The genome of the Korean SPLCV isolate (SPLCV-KR) comprises 2,828 nucleotides with six open reading frames in DNA-A, similar to a monopartite begomovirus. Additionally, neither the genome B genomic component nor the DNA beta sequence was detected. The results of phylogenetic analysis using the maximum parsimony method showed that SPLCV-KR is more closely related to SPLCV-US (US) than SPLCV-CN (China) and SPLCV-JP (Japan). A tandem repeat dimer of SPLCV-KR was cloned and found to be infectious in sweet potatoes (Ipomoea batatas) via biolistic inoculation. The SPLCV-infected sweet potatoes exhibited mild leaf curl symptoms of SPLCD, and the newly-replicated viral DNA was detected via Southern blot analysis. Results of biotic, molecular, and phylogenetic characterization suggest that SPLCV-KR is a new strain of SPLCV and is importantly placed in the evolutionary progression from curtoviruses to begomoviruses. KEYWORDS: sweet potato leaf curl virus; sweet potato leaf curl disease; phylogenetic analysis; infectious clone; biolistic infection.


Asunto(s)
Begomovirus/genética , Begomovirus/aislamiento & purificación , Ipomoea batatas/virología , Enfermedades de las Plantas/virología , Secuencia de Bases , Begomovirus/clasificación , Genoma Viral , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Filogenia , República de Corea , Proteínas Virales/genética
10.
Nat Commun ; 12(1): 5436, 2021 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-34521833

RESUMEN

The rich phenomena in the FeSe and related compounds have attracted great interests as it provides fertile material to gain further insight into the mechanism of high temperature superconductivity. A natural follow-up work was to look into the possibility of superconductivity in MnSe. We demonstrated in this work that high pressure can effectively suppress the complex magnetic characters of MnSe, and induce superconductivity with Tc ~ 5 K at pressure ~12 GPa confirmed by both magnetic and resistive measurements. The highest Tc is ~ 9 K (magnetic result) at ~35 GPa. Our observations suggest the observed superconductivity may closely relate to the pressure-induced structural change. However, the interface between the metallic and insulating boundaries may also play an important role to the pressure induced superconductivity in MnSe.

11.
Soc Sci Med ; 253: 112940, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32234584

RESUMEN

BACKGROUND: Stigma can exacerbate negative health outcomes in people living with HIV (PLWH). This longitudinal, cluster randomized controlled trial in rural Mpumalanga, South Africa, examined the interdependence of HIV-related stigma among pregnant couples living with HIV, and the potential impact of a lay health worker delivered intervention, Protect Your Family, on changes in stigma over time across couples, controlling for physical intimate partner violence (IPV), verbal IPV, gender, HIV knowledge, and months since HIV diagnosis. Using a form of the Actor-Partner Interdependence model, changes in stigma over time were also examined within each dyad of seroconcordant participants with HIV. METHOD: Antenatal clinics were randomized to experimental or control conditions, and participants completed baseline antenatal and 12-month postpartum assessments. Both women and male partners participated in intervention sessions in gender concordant groups and couple or individual sessions. RESULTS: Multilevel models (N = 1475) revealed stigma was related to condition and verbal intimate partner violence, but not time. Using an Actor-Partner Interdependence cross-lagged path model to examine within dyad changes in stigma for seroconcordant couples (n = 201), intervention condition participants' stigma levels were not interdependent over time. Women's 12-month stigma was related to their partners' stigma at baseline in the control condition, but not in the intervention condition. DISCUSSION: Compared to women in the control condition, postpartum stigma among women in the intervention condition was not related to their male partners' stigma, suggesting that women's perception of stigma became uncoupled from that of their partners. The intervention may have promoted female empowerment to shape their own beliefs and attitudes towards what it means to be infected with HIV, and express their own agency in responding to how others treat them and they treat themselves.


Asunto(s)
Infecciones por VIH , Violencia de Pareja , Femenino , Humanos , Masculino , Embarazo , Población Rural , Parejas Sexuales , Estigma Social , Sudáfrica
12.
Gut Microbes ; 12(1): 1732852, 2020 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-32167011

RESUMEN

BACKGROUND: . Oral administration of bovine antibodies active against enterotoxigenic Escherichia coli (ETEC) have demonstrated safety and efficacy against diarrhea in human challenge trials. The efficacy of bovine serum immunoglobulins (BSIgG) against recombinant colonization factor CS6 or whole cell ETEC strain B7A was assessed against challenge with the CS6-expressing B7A. METHODS: . This was a randomized, double-blind, placebo-controlled trial in which healthy adults received oral hyperimmune BSIgG anti-CS6, anti-B7A whole cell killed or non-hyperimmune BSIgG (placebo) in a 1:1:1 ratio then challenged with ETEC B7A. Two days pre-challenge, volunteers began a thrice daily, seven day course of immunoprophylaxis. On day 3, subjects received 1 × 1010 CFUs of B7A. Subjects were observed for safety and the primary endpoint of moderate-severe diarrhea (MSD). RESULTS: . A total of 59 volunteers received product and underwent ETEC challenge. The BSIgG products were well-tolerated across all subjects. Upon challenge, 14/20 (70%) placebo recipients developed MSD, compared to 12/19 (63%; p = .74) receiving anti-CS6 BSIgG and 7/20 (35%; p = .06) receiving anti-B7A BSIgG. Immune responses to the ETEC infection were modest across all groups. CONCLUSIONS: . Bovine-derived serum antibodies appear safe and well tolerated. Antibodies derived from cattle immunized with whole cell B7A provided 50% protection against MSD following B7A challenge; however, no protection was observed in subjects receiving serum antibodies targeting CS6. The lack of observed efficacy in this group may be due to low CS6 surface expression on B7A, the high dose challenge inoculum and/or the use of serum derived antibodies versus colostrum-derived antibodies.


Asunto(s)
Anticuerpos Antibacterianos/inmunología , Antígenos Bacterianos/inmunología , Escherichia coli Enterotoxigénica/inmunología , Infecciones por Escherichia coli/tratamiento farmacológico , Proteínas de Escherichia coli/inmunología , Vacunas contra Escherichia coli/inmunología , Adolescente , Adulto , Animales , Anticuerpos Antibacterianos/administración & dosificación , Bovinos , Diarrea/tratamiento farmacológico , Método Doble Ciego , Enterotoxinas/inmunología , Femenino , Humanos , Inmunoglobulina G/administración & dosificación , Inmunoglobulina G/inmunología , Masculino , Persona de Mediana Edad , Placebos/administración & dosificación , Profilaxis Pre-Exposición , Adulto Joven
13.
Science ; 213(4504): 233-5, 1981 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-6787705

RESUMEN

Biologically active compounds were entrapped in cross-linked serum albumin microbeads. Injection of these drug-impregnated beads into rabbits produced no adverse immunological reactions. Sustained release (20 days) of progesterone was demonstrated in vivo.


Asunto(s)
Progesterona/administración & dosificación , Albúmina Sérica Bovina/administración & dosificación , Animales , Preparaciones de Acción Retardada , Glutaral , Inyecciones Intramusculares , Inyecciones Subcutáneas , Cinética , Masculino , Microscopía Electrónica de Rastreo , Norgestrel/administración & dosificación , Progesterona/sangre , Conejos
14.
Acta Neurochir Suppl ; 101: 39-43, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18642632

RESUMEN

OBJECTIVE: The authors report stereotactically created lesioning by radiofrequency or Cyberknife radiosurgery for patients with mental illness. MATERIALS AND METHODS: Since 1993, thirty-eight patients have undergone stereotactic psychosurgery for medically intractable mental illnesses. Two patients had aggressive behavior. Twenty-five patients suffered from Obsessive-Compulsive Disorder (OCD) and ten patients had depression. Another patient suffered from atypical psychosis. Bilateral amygdalotomy and subcaudate tractotomy were done for aggressive behavior. Limbic leucotomy or anterior cingulotomy was done for OCD and subcaudate tractotomy with or without cingulotomy was done for depression. In twenty-three patients, the lesions were made by a radiofrequency (RF) lesion generator. In fifteen cases, the lesions were made with CyberKnife Radiosurgery (CKRS). RESULTS: The Overt Aggression Scale (OAS) declined from 8 to 2 with clinical improvement during follow up period. With long-term follow up (meaning 57 months) in 25 OCDs, the mean Yale Brown Obsessive Compulsive Score (YBOCS) declined from 34 to 13 (n = 25). The Hamilton Depression scale (HAMD) for ten patients with depression declined from 38.5 to 10.5 (n = 10). There was no operative mortality and no significant morbidity except one case with transient urinary incontinence. CONCLUSION: Authors suggest that stereotactic psychosurgery by RF and CKRS could be a safe and effective means of treating some medically intractable mental illnesses.


Asunto(s)
Trastornos Mentales/cirugía , Radiocirugia/métodos , Humanos , Estudios Longitudinales , Imagen por Resonancia Magnética , Trastornos Mentales/clasificación , Pruebas Neuropsicológicas , Escalas de Valoración Psiquiátrica , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
15.
Anat Histol Embryol ; 47(1): 64-70, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29152768

RESUMEN

GABAergic interneurons regulate the degree of glutamatergic excitation and output of projection neurons. In this study, we investigated the distribution of calbindinD-28k (CB) and parvalbumin (PV) in the somatosensory area of the pigeon pallium using immunohistochemical method. Our results show that anatomical structures of the somatosensory area of the pigeon pallium consisted of several subdivisions including the hyperpallium, intercalated hyperpallium, mesopallium, nidopallium and basorostralis. Neuronal density was significantly higher in the intercalated hyperpallium and basorostralis than that in the other subdivisions. The density of the CB immunoreactive neurons was generally similar in all the subdivisions; however, the density of PV immunoreactive neurons was particularly prominent in the basorostralis compared with that in the other subdivisions. In addition, the mean proportion of PV immunoreactive neurons to total neurons was higher than that in the CB immunoreactive neurons in all the subdivisions. In brief, our present study shows that PV immunoreactive neurons in the somatosensory area of the pigeon pallium were significantly abundant compared with CB immunoreactive neurons. This finding needs more studies regarding CB- and PV-related functions in the somatosensory area of the avian pallium.


Asunto(s)
Calbindina 1/metabolismo , Columbidae/metabolismo , Neuronas/metabolismo , Parvalbúminas/metabolismo , Corteza Somatosensorial/metabolismo , Animales , Benzoxazinas , Recuento de Células/veterinaria , Colorantes , Sustancia Gris/citología , Sustancia Gris/metabolismo , Inmunohistoquímica/veterinaria , Masculino , Neuronas/citología , Corteza Somatosensorial/citología , Telencéfalo/citología , Telencéfalo/metabolismo , Sustancia Blanca/citología , Sustancia Blanca/metabolismo
16.
J Clin Invest ; 73(6): 1524-31, 1984 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-6373826

RESUMEN

Experiments were carried out to examine relationships between alveolar macrophage maturity and amounts of tissue factor (Clotting Factor III) in these cells under physiologic conditions and during immunologically induced pneumonitis. Using discontinuous density gradient centrifugation, alveolar macrophages from healthy rabbits were rapidly isolated into five subpopulations at different stages of maturation, as demonstrated by morphologic and morphometric evaluation. Very large amounts of tissue factor activity were found in fully mature cells that were purified in the lowest density subpopulation and assayed without preliminary in vitro stimulation or culture. In the remaining four subpopulations of increasing density, amounts of tissue factor were found to progressively diminish in direct correlation with declines of cell maturity. These differences at mean levels were as great as 35-fold. In addition, blood monocytes had less than 1/219 and less than 1/6 of the activity of the fully mature and the least mature subpopulations, respectively. After 16 h culture of the five isolated subpopulations in the absence of lymphokines or of significant numbers of lymphocytes, tissue factor activity increased in inverse correlation with the preincubation stage of cell maturity (2,387 and 109% in the least mature and most mature subpopulations, respectively). These increases required protein synthesis and were accompanied by morphologic and morphometric changes which indicated cellular maturation during the period of tissue factor activity generation in vitro, thus further demonstrating relationships between macrophage maturity and tissue factor content. In additional experiments, direct correlations between cell maturity and tissue factor activity content were also found in activated alveolar macrophage populations from rabbits with Bacillus Calmette Guering (BCG)-induced granulomatous pneumonitis. However, as compared with controls, the BCG populations had increased total amounts of tissue factor activity due to the presence of large numbers of mature alveolar macrophage forms that had high levels of the procoagulant. Thus, tissue factor activity in alveolar macrophages is a marker of cellular maturation in vivo and in vitro. Increased amounts of this initiator of the extrinsic clotting pathway, as found in alveolar macrophage populations from animals with granulomatous pneumonitis induced by BCG hypersensitivity, suggest that alveolar macrophage tissue factor may contribute to the pathology of immune lung diseases.


Asunto(s)
Macrófagos/fisiología , Neumonía/fisiopatología , Tromboplastina/fisiología , Animales , Separación Celular , Células Cultivadas , Femenino , Macrófagos/citología , Monocitos/citología , Monocitos/fisiología , Mycobacterium bovis/patogenicidad , Conejos , Tuberculosis/fisiopatología
17.
Nat Biotechnol ; 15(10): 971-5, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9335047

RESUMEN

Deficiency or abnormality of coagulation factor VIII (FVIII) causes a bleeding disorder called hemophilia A. Treatment involves FVIII concentrates prepared from pooled human plasma or recombinant FVIII (rFVIII) prepared from mammalian cell culture. The cost of highly purified FVIII or rFVIII is a major factor in hemophilia therapy and restricts prophylaxis. We have sought to generate a new source of rFVIII by targeting expression of the human FVIII cDNA to the mammary gland of transgenic pigs using the regulatory sequences of the mouse whey acidic protein gene. The identity of processed heterodimeric rFVIII was confirmed using specific antibodies, by thrombin digestion and activity assays. The secretion of as much as 2.7 micrograms/ml of rFVIII in milk was over tenfold higher than in normal plasma. Up to 0.62 U/ml of rFVIII was detected in an assay in which rFVIII restored normal clotting activity to FVIII-deficient human plasma.


Asunto(s)
ADN Complementario/biosíntesis , Factor VIII/biosíntesis , Glándulas Mamarias Animales/metabolismo , Leche/química , Porcinos/genética , Animales , Animales Modificados Genéticamente , Coagulación Sanguínea/efectos de los fármacos , Dimerización , Factor VIII/genética , Factor VIII/farmacología , Femenino , Regulación de la Expresión Génica/genética , Hemofilia A/tratamiento farmacológico , Hemofilia A/economía , Humanos , Ratones , Proteínas de la Leche/genética , Proteínas Recombinantes/biosíntesis , Trombina
18.
J Thromb Haemost ; 15(4): 709-720, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28109042

RESUMEN

Essentials Recombinant factor VIII (FVIII) is known to be expressed at a low level in cell culture. To increase expression, we used codon-optimization of a B-domain deleted FVIII (BDD-FVIII). This resulted in 7-fold increase of the expression level in cell culture. The biochemical properties of codon-optimized BDD-FVIII were similar to the wild-type protein. SUMMARY: Background Production of recombinant factor VIII (FVIII) is challenging because of its low expression. It was previously shown that codon-optimization of a B-domain-deleted FVIII (BDD-FVIII) cDNA resulted in increased protein expression. However, it is well recognized that synonymous mutations may affect the protein structure and function. Objectives To compare biochemical properties of a BDD-FVIII variants expressed from codon-optimized and wild-type cDNAs (CO and WT, respectively). Methods Each variant of the BDD-FVIII was expressed in several independent Chinese hamster ovary (CHO) cell lines, generated using a lentiviral platform. The proteins were purified by two-step affinity chromatography and analyzed in parallel by PAGE-western blot, mass spectrometry, circular dichroism, surface plasmon resonance, and chromogenic, clotting and thrombin generation assays. Results and conclusion The average yield of the CO was 7-fold higher than WT, whereas both proteins were identical in the amino acid sequences (99% coverage) and very similar in patterns of the molecular fragments (before and after thrombin cleavage), glycosylation and tyrosine sulfation, secondary structures and binding to von Willebrand factor and to a fragment of the low-density lipoprotein receptor-related protein 1. The CO preparations had on average 1.5-fold higher FVIII specific activity (activity normalized to protein mass) than WT preparations, which was attributed to better preservation of the CO structure as a result of considerably higher protein concentrations during the production. We concluded that the codon-optimization of the BDD-FVIII resulted in significant increase of its expression and did not affect the structure-function properties.


Asunto(s)
Codón , Factor VIII/genética , Ingeniería de Proteínas , Animales , Células CHO , Línea Celular , Cricetinae , Cricetulus , ADN Complementario/metabolismo , Factor VIII/metabolismo , Vectores Genéticos , Glicosilación , Humanos , Lentivirus , Mutación , Fragmentos de Péptidos/genética , Estructura Secundaria de Proteína , Relación Estructura-Actividad , Tirosina/química
19.
Anat Histol Embryol ; 46(6): 528-532, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28901020

RESUMEN

Few studies regarding the anatomical distribution of motor neurons innervating muscles of the arm have been demonstrated in avian brains. The purpose of this study was to finely determine the localization of cerebral neurons innervating the biceps brachii muscle in the pigeon. The cholera toxin B subunit (CTB) was employed as a retrograde tracer to determine the location of neurons controlling the biceps brachii muscle in the telencephalon following intramuscular injection in male pigeons (n = 7), which were killed 14 days after intramuscular injection with CTB. We found that CTB-labelled neurons were located contralaterally in the hyperpallium apicale of the rostral telencephalon and that most of the CTB-labelled neurons were pyramidal in shape. This study shows that CTB is easily taken up by nerve terminals which innervate the biceps brachii muscle of the pigeon and that cerebral motor neurons controlling the biceps brachii muscle are located in the hyperpallium apicale.


Asunto(s)
Columbidae/anatomía & histología , Músculo Esquelético/inervación , Neuronas/citología , Telencéfalo/citología , Alas de Animales/inervación , Animales , Benzoxazinas , Toxina del Cólera , Colorantes , Columbidae/fisiología , Masculino , Músculo Esquelético/citología , Músculo Esquelético/fisiología , Alas de Animales/citología , Alas de Animales/fisiología
20.
Class Quantum Gravity ; 34(No 6)2017.
Artículo en Inglés | MEDLINE | ID: mdl-29722360

RESUMEN

With the first direct detection of gravitational waves, the advanced laser interferometer gravitational-wave observatory (LIGO) has initiated a new field of astronomy by providing an alternative means of sensing the universe. The extreme sensitivity required to make such detections is achieved through exquisite isolation of all sensitive components of LIGO from non-gravitational-wave disturbances. Nonetheless, LIGO is still susceptible to a variety of instrumental and environmental sources of noise that contaminate the data. Of particular concern are noise features known as glitches, which are transient and non-Gaussian in their nature, and occur at a high enough rate so that accidental coincidence between the two LIGO detectors is non-negligible. Glitches come in a wide range of time-frequency-amplitude morphologies, with new morphologies appearing as the detector evolves. Since they can obscure or mimic true gravitational-wave signals, a robust characterization of glitches is paramount in the effort to achieve the gravitational-wave detection rates that are predicted by the design sensitivity of LIGO. This proves a daunting task for members of the LIGO Scientific Collaboration alone due to the sheer amount of data. In this paper we describe an innovative project that combines crowdsourcing with machine learning to aid in the challenging task of categorizing all of the glitches recorded by the LIGO detectors. Through the Zooniverse platform, we engage and recruit volunteers from the public to categorize images of time-frequency representations of glitches into pre-identified morphological classes and to discover new classes that appear as the detectors evolve. In addition, machine learning algorithms are used to categorize images after being trained on human-classified examples of the morphological classes. Leveraging the strengths of both classification methods, we create a combined method with the aim of improving the efficiency and accuracy of each individual classifier. The resulting classification and characterization should help LIGO scientists to identify causes of glitches and subsequently eliminate them from the data or the detector entirely, thereby improving the rate and accuracy of gravitational-wave observations. We demonstrate these methods using a small subset of data from LIGO's first observing run.

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