325 research outputs found

    An Audio-visual Solution to Sound Source Localization and Tracking with Applications to HRI

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    Robot audition is an emerging and growing branch in the robotic community and is necessary for a natural Human-Robot Interaction (HRI). In this paper, we propose a framework that integrates advances from Simultaneous Localization And Mapping (SLAM), bearing-only target tracking, and robot audition techniques into a unifed system for sound source identification, localization, and tracking. In indoors, acoustic observations are often highly noisy and corrupted due to reverberations, the robot ego-motion and background noise, and possible discontinuous nature of them. Therefore, in everyday interaction scenarios, the system requires accommodating for outliers, robust data association, and appropriate management of the landmarks, i.e. sound sources. We solve the robot self-localization and environment representation problems using an RGB-D SLAM algorithm, and sound source localization and tracking using recursive Bayesian estimation in the form of the extended Kalman Filter with unknown data associations and an unknown number of landmarks. The experimental results show that the proposed system performs well in the medium-sized cluttered indoor environment

    Immunization with one Theileria parva strain results in similar level of CTL strain-specificity and protection compared to immunization with the three-component Muguga cocktail in MHC-matched animals

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    Abstract Background The tick-borne protozoan parasite Theileria parva causes a usually fatal cattle disease known as East Coast fever in sub-Saharan Africa, with devastating consequences for poor small-holder farmers. Immunity to T. parva, believed to be mediated by a cytotoxic T lymphocyte (CTL) response, is induced following natural infection and after vaccination with a live vaccine, known as the Infection and Treatment Method (ITM). The most commonly used version of ITM is a combination of parasites derived from three isolates (Muguga, Kiambu 5 and Serengeti-transformed), known as the “Muguga cocktail”. The use of a vaccine comprising several strains is believed to be required to induce a broad immune response effective against field challenge. In this study we investigated whether immunization with the Muguga cocktail induces a broader CTL response than immunization with a single strain (Muguga). Results Four MHC haplotype-matched pairs of cattle were immunized with either the trivalent Muguga cocktail or the single Muguga strain. CTL specificity was assessed on a panel of five different strains, and clonal responses to these strains were also assessed in one of the MHC-matched pairs. We did not find evidence for a broader CTL response in animals immunized with the Muguga cocktail compared to those immunized with the Muguga strain alone, in either the bulk or clonal CTL analyses. This was supported by an in vivo trial in which all vaccinated animals survived challenge with a lethal dose of the Muguga cocktail vaccine stabilate. Conclusion We did not observe any substantial differences in the immunity generated from animals immunized with either Muguga alone or the Muguga cocktail in the animals tested here, corroborating earlier results showing limited antigenic diversity in the Muguga cocktail. These results may warrant further field studies using single T. parva strains as future vaccine candidates

    Does the surgeon still have a role to play in the diagnosis and management of lymphomas?

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    <p>Abstract</p> <p>Background</p> <p>Over the course of the past 40 years, there have been a significant number of changes in the way in which lymphomatous disease is diagnosed and managed. With the advent of computed tomography, there is little role for staging laparotomy and the surgeon's role may now more diagnostic than therapeutic.</p> <p>Aims</p> <p>To review all cases of lymphoma diagnosed at a single institution in order determine the current role of the surgeon in the diagnosis and management of lymphoma.</p> <p>Patients and methods</p> <p>Computerized pathology records were reviewed for a five-year period 1996 to 2000 to determine all cases of lymph node biopsy (incisional or excisional) in which tissue was obtained as part of a planned procedure. Cases of incidental lymphadenopathy were thus excluded.</p> <p>Results</p> <p>A total of 297 biopsies were performed of which 62 (21%) yielded lymphomas. There were 22 females and 40 males with a median age of 58 years (range: 19–84 years). The lymphomas were classified as 80% non-Hodgkin's lymphoma, 18% Hodgkin's lymphoma and 2% post-transplant lymphoproliferative disorder. Diagnosis was established by general surgeons (n = 48), ENT surgeons (n = 9), radiologists (n = 4) and ophthalmic surgeons (n = 1). The distribution of excised lymph nodes was: cervical (n = 23), inguinal (n = 15), axillary (n = 11), intra-abdominal (n = 6), submandibular (n = 2), supraclavicular (n = 2), periorbital (n = 1), parotid (n = 1) and mediastinal (n = 1). Fine needle aspiration cytology had been performed prior to biopsy in only 32 (52%) cases and had suggested: lymphoma (n = 10), reactive changes (n = 13), normal (n = 5), inadequate (n = 4). The majority (78%) of cervical lymph nodes were subjected to FNAC prior to biopsy whilst this was performed in only 36% of non-cervical lymphadenopathy.</p> <p>Conclusion</p> <p>The study has shown that lymphoma is a relatively common cause of surgical lymphadenopathy. Given the limitations of FNAC, all suspicious lymph nodes should be biopsied following FNAC even if the FNAC is reported normal or demonstrating reactive changes only. With the more widespread application of molecular techniques, and the development of improved minimally-invasive procedures, percutaneous and endoscopic techniques may come to dominate, however, at present; the surgeon still has an important role to play in the diagnosis if not treatment of lymphomas.</p

    Caracterización de pacientes con mielopatía espondilótica cervical intervenidos por disectomía anterior

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    Introduction: cervical spondylotic myelopathy is a common disease, which accounts for a quarter of all upper-limb paresthesia. Anterior graft discectomy is one of the most widely used surgical techniques in the world to treat this disease.Objective: to characterize patients with cervical spondylotic myelopathy who underwent surgery using the anterior discectomy with graft technique.Methods: a retrospective, descriptive, longitudinal study was conducted in 35 patients with cervical spondylotic myelopathy who underwent surgery using the anterior graft discectomy technique at “Lucia Iñiguez Landín” Clinical Surgical Teaching Hospital from January 2017 to December 2019. The variables studied were: age, sex, race, personal pathological history, signs and symptoms (before the surgery), cervical level affected, sequelae and complications.Results: male patients predominated (59,9 %), with ages between 45 and 60 years (45,71 %) and with personal pathological history of obesity (40 %). The prevailing clinical manifestations before surgery were hyperreflexia (65,71 %) and paresthesia (62,85 %). The most affected cervical segment was C5-C7 (91,42 %). The main complications were generalized hyperreflexia (17,14 %) and pain (8,57 %).Conclusions: patients with cervical spondylotic myelopathy surgically treated by the anterior discectomy with graft technique were mostly male, in ages after the fourth decade of life. Patients presented hyperreflexia before the surgery, and could develop generalized hyperreflexia as a complication.Introducción: la mielopatía espondilótica cervical es una enfermedad frecuente, que representa la cuarta parte de las parestesias en miembros superiores.  La disectomía anterior con injerto es una de las técnicas quirúrgicas más utilizadas en el mundo para tratar esta enfermedad.Objetivo: Caracterizar los pacientes con mielopatía espondilótica cervical intervenidos quirúrgicamente por la técnica disectomía anterior con injerto.Método: Se realizó un estudio observacional, descriptivo, longitudinal retrospectivo en 35 pacientes con mielopatía espondilótica cervical intervenidos quirúrgicamente por la técnica de disectomía anterior con injerto en el Hospital Clínico Quirúrgico Docente “Lucia Iñiguez Landín” en el período de enero del 2017 a diciembre del 2019. Las variables estudiadas fueron: edad, sexo, color de piel, antecedentes patológicos personales, signos y síntomas (antes de la operación), nivel cervical afectado, secuelas y complicaciones.Resultados: Se encontró predominio de pacientes masculinos (59,9 %), con edades entre 45 y 60 años (45,71 %) y con antecedentes patológicos personales de obesidad (40 %). Las manifestaciones clínicas que predominaron antes de la intervención quirúrgica fueron la hiperreflexia (65,71 %) y la parestesia (62,85 %). El segmento cervical más afectado fue C5-C7 (91,42 %). Las principales complicaciones fueron la hiperreflexia generalizada (17,14 %) y el dolor (8,57).Conclusiones: los pacientes con mielopatía espondilótica cervical intervenidos quirúrgicamente por la técnica disectomía anterior con injerto fueron de sexo masculino en su mayoría, con edades pasadas de la cuarta década de vida. Los pacientes presentaron hiperreflexia antes de la operación, pudiendo desarrollar hiperreflexia generalizada como complicación

    Efficacy of a 3 month training program on the jump-landing technique in jump-landing sports. Design of a cluster randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>With the relatively high rate of injuries to the lower extremity due to jump-landing movement patterns and the accompanied high costs, there is need for determining potential preventive programs. A program on the intervention of jump-landing technique is possibly an important preventative measure since it appeared to reduce the incidence of lower extremity injuries. In real life situations, amateur sports lack the infrastructure and funds to have a sports physician or therapist permanently supervising such a program. Therefore the current prevention program is designed so that it could be implemented by coaches alone.</p> <p>Objective</p> <p>The objective of this randomized controlled trial is to evaluate the effect of a coach supervised intervention program targeting jump-landing technique on the incidence of lower extremity injuries.</p> <p>Methods</p> <p>Of the 110 Flemish teams of the elite division, 24 teams are included and equally randomized to two study groups. An equal selection of female and male teams with allocation to intervention and control group is obtained. The program is a modification of other prevention programs previously proven to be effective. All exercises in the current program are adjusted so that a more progressive development in the exercise is presented. Both the control and intervention group continue with their normal training routine, while the intervention group carries out the program on jump-landing technique. The full intervention program has a duration of three months and is performed 2 times a week during warm-up (5-10 min). Injuries are registered during the entire season.</p> <p>Discussion</p> <p>The results of this study can give valuable information on the effect of a coach supervised intervention program on jump-landing technique and injury occurrence. Results will become available in 2011.</p> <p>Trial registration</p> <p>Trial registration number: NTR2560</p

    An ISO Long Wavelength Spectrometer detection of CH in NGC 7027 and an HeH + upper limit

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    We have detected an emission line at 149.18 ± 0.06 Ωm in the ISO Long Wavelength Spectrometer (LWS) grating spectrum of the planetary nebula NGC 7027. This Une coincides in wavelength with both the HeH+ J=1-0 fundamental pure rotational line at 149.14 urn and the CH 2Π3/2 (F2) J=3/2-2Πl/2 (F2) 7= 1/2 fundamental pure rotational lines at 149.09 and 149.39 μm. Another feature of similar strength at 180.7 urn is well-fitted by the CH doublet 2Π1/2 (F1) J=5/2-3/2 at 180.48 and 180.93 μm. We therefore attribute both the 149.18- and 180.7-um lines to CH, the first evidence of this molecule in NGC 7027 and the first detection anywhere of the far-infrared lines of CH in emission. We estimate a CH/CO abundance ratio of ∼ 0.06 and a CH/CH+ ratio of ∼0.2, the latter being more than an order of magnitude lower than predicted for photodissociation regions. The contribution from the HeH+ J=1−0 line to the 149.18-μm feature is at least a factor of three lower than the predictions of Cecchi-Pestellini & Dalgarno (1993)

    Processing of Body Odor Signals by the Human Brain

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    Brain development in mammals has been proposed to be promoted by successful adaptations to the social complexity as well as to the social and non-social chemical environment. Therefore, the communication via chemosensory signals might have been and might still be a phylogenetically ancient communication channel transmitting evolutionary significant information. In humans, the neuronal underpinnings of the processing of social chemosignals have been investigated in relation to kin recognition, mate choice, the reproductive state and emotional contagion. These studies reveal that human chemosignals are probably not processed within olfactory brain areas but through neuronal relays responsible for the processing of social information. It is concluded that the processing of human social chemosignals resembles the processing of social signals originating from other modalities, except that human social chemosignals are usually communicated without the allocation of attentional resources, that is below the threshold of consciousness. Deviances in the processing of human social chemosignals might be related to the development and maintenance of mental disorders

    Sexual dimorphism in relation to adipose tissue and intrahepatocellular lipid deposition in early infancy

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    Sexual dimorphism in adiposity is well described in adults, but the age at which differences first manifest is uncertain. Using a prospective cohort, we describe longitudinal changes in directly measured adiposity and intrahepatocellular lipid (IHCL) in relation to sex in healthy term infants. At median ages of 13 and 63 days, infants underwent quantification of adipose tissue depots by whole-body magnetic resonance imaging and measurement of IHCL by in vivo proton magnetic resonance spectroscopy. Longitudinal data were obtained from 70 infants (40 boys and 30 girls). In the neonatal period girls are more adipose in relation to body size than boys. At follow-up (median age 63 days), girls remained significantly more adipose. The greater relative adiposity that characterises girls is explained by more subcutaneous adipose tissue and this becomes increasingly apparent by follow-up. No significant sex differences were seen in IHCL. Sex-specific differences in infant adipose tissue distribution are in keeping with those described in later life, and suggest that sexual dimorphism in adiposity is established in early infancy

    Urinary C-Peptide Measurement as a Marker of Nutritional Status in Macaques

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    Studies of the nutritional status of wild animals are important in a wide range of research areas such as ecology, behavioural ecology and reproductive biology. However, they have so far been strongly limited by the indirect nature of the available non-invasive tools for the measurement of individual energetic status. The measurement of urinary C-peptide (UCP), which in humans and great apes shows a close link to individual nutritional status, may be a more direct, non-invasive tool for such studies in other primates as well and possibly even in non-primate mammals. Here, we test the suitability of UCPs as markers of nutritional status in non-hominid primates, investigating relationships between UCPs and body-mass-index (BMI), skinfold fatness, and plasma C-peptide levels in captive and free-ranging macaques. We also conducted a food reduction experiment, with daily monitoring of body weight and UCP levels. UCP levels showed significant positive correlations with BMI and skinfold fatness in both captive and free-ranging animals and with plasma C-peptide levels in captive ones. In the feeding experiment, UCP levels were positively correlated with changes in body mass and were significantly lower during food reduction than during re-feeding and the pre-experimental control condition. We conclude that UCPs may be used as reliable biomarkers of body condition and nutritional status in studies of free-ranging catarrhines. Our results open exciting opportunities for energetic studies on free-ranging primates and possibly also other mammals

    Approaches to vaccination against Theileria parva and Theileria annulata

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    Despite having different cell tropism, the pathogenesis and immunobiology of the diseases caused by Theileria parva and Theileria annulata are remarkably similar. Live vaccines have been available for both parasites for over 40 years, but although they provide strong protection, practical disadvantages have limited their widespread application. Efforts to develop alternative vaccines using defined parasite antigens have focused on the sporozoite and intracellular schizont stages of the parasites. Experimental vaccination studies using viral vectors expressing T. parva schizont antigens and T. parva and T. annulata sporozoite antigens incorporated in adjuvant have, in each case, demonstrated protection against parasite challenge in a proportion of vaccinated animals. Current work is investigating alternative antigen delivery systems in an attempt to improve the levels of protection. The genome architecture and protein-coding capacity of T. parva and T. annulata are remarkably similar. The major sporozoite surface antigen in both species and most of the schizont antigens are encoded by orthologous genes. The former have been shown to induce species cross-reactive neutralizing antibodies, and comparison of the schizont antigen orthologues has demonstrated that some of them display high levels of sequence conservation. Hence, advances in development of subunit vaccines against one parasite species are likely to be readily applicable to the other
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