815 research outputs found

    Biomimetic Based EEG Learning for Robotics Complex Grasping and Dexterous Manipulation

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    There have been tremendous efforts to understand the biological nature of human grasping, in such a way that it can be learned and copied to prosthesis–robotics and dextrous grasping applications. Several biomimetic methods and techniques have been adopted, hence applied to analytically comprehend ways human performs grasping to duplicate human knowledge. A major topic for further study, is related to decoding the resulting EEG brainwaves during motorizing of fingers and moving parts. To accomplish this, there are a number of phases that are performed, including recording, pre-processing, filtration, and understanding of the waves. However, there are two important phases that have received substantial research attentions. The classification and decoding, of such massive and complex brain waves, as they are two important steps towards understanding patterns during grasping. In this respect, the fundamental objective of this research is to demonstrate how to employ advanced pattern recognition methods, like fuzzy c-mean clustering for understanding resulting EEG brain waves, in such a way to control a prosthesis or robotic hand, while relying sets of detected EEG brainwaves. There are a number of decoding and classification methods and techniques, however we shall look into fuzzy based clustering blended with principle component analysis (PAC) technique to help for the decoding mechanism. EEG brainwaves during a grasping and manipulation have been used for this analysis. This involves, movement of almost five fingers during a grasping defined task. The study has found that, it is not a straight forward task to decode all human fingers motions, as due to the complexity of grasping tasks. However, the adopted analysis was able to classify and identify the different narrowly performed and related fundamental events during a simple grasping task

    A case study with breast cancer and brain metastasis encompassing acute onset of amnesia and altered mental status due to limbic encephalitis - biochemical and proteomic aspects

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    A biochemical case study is reported on a 50-year old lady known to have breast cancer. The woman was treated by mastectomy and this was followed by unraveling brain metastases three years post-diagnosis of the cancer, which was treated by radiation and chemotherapy. Two months after ending her treatment, she exhibited acute changes in her mental status manifested by severe amnesia and fever. A generalized analytical and biochemical assessment revealed the presence of paraneoplastic limbic encephalitis

    WISE-2005: prolongation of left ventricular pre-ejection period with 56 days head-down bed rest in women

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    This study tested the hypothesis that prolonged physical deconditioning affects the coupling of left ventricular depolarization to its ejection (the pre-ejection period, PEPi) and that this effect is minimized by exercise countermeasures. Following assignment to non-exercise (Control) and exercise groups (Exercise), 14 females performed 56 days of continuous head-down tilt bed rest. Measurements of the electrocardiogram (ECG) and stroke volume (Doppler ultrasound) during supine rest were obtained at baseline prior to (Pre) and after (Post) the head-down tilt bed rest (HDBR) period. Compared with Pre, the PEPi was increased following head-down tilt bed rest (main effect, P \u3c 0.005). This effect was most dominant in the Control group [Pre = 0.038 ± 0.06 s (s.d.) versus Post = 0.054 ± 0.011 s; P \u3c 0.001]. In the Exercise group, PEPi was 0.032 ± 0.005 s Pre and 0.038 ± 0.018 s Post; P= 0.08. Neither the QRS interval nor cardiac afterload was modified by head-down tilt bed rest in Control or Exercise groups. Low-dose isoprenaline infusion reversed the head-down tilt bed rest-induced delay in the PEPi. These results suggest that head-down tilt bed rest leads to a delayed onset of systolic ejection following left ventricular depolarization in a manner that is affected little by the exercise countermeasure but is related to Β-adrenergic pathways. The delayed onset of systole following head-down tilt bed rest appears to be related to mechanism(s) affecting contraction of the left ventricle rather than its depolarization. © 2010 The Authors. Journal compilation © 2010 The Physiological Society

    Caracterização de sementes de variedades locais de feijão-de-corda (Vigna unguiculata) do Acre.

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    O feijão-de-corda (Vigna unguiculata) apresenta grande importância social, cultural, agronômica e econômica para os agricultores familiares no Acre que trouxeram o hábito de cultivo e consumo do feijão-de-corda do Nordeste. Este trabalho teve como objetivo caracterizar as sementes de variedades locais de feijão-de-corda coletadas em feiras e mercados públicos em diversos municípios do Acre no primeiro semestre de 2012. Em laboratório foram identificados descritores biométricos, forma, cor, brilho e peso de 100 sementes. Foram detectadas cinco formas de sementes, quatro cores distintas e três classes de brilho sendo duas variedades opacas. As variedades mostraram grande variabilidade no fator peso de 100 sementes com amplitude de 26,9 g. Quanto aos caracteres quantitativos observou-se grande variação nos valores de comprimento, largura e espessura das sementes entre as variedades mostrando que há variação genética entre os quinze cultivares de feijão-de-corda avaliados

    Germinação e florescimento de cultivares locais de feijão-de-corda e feijoeiro comum em Rio Branco, Acre.

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    Este trabalho teve como objetivo quantificar os processos de germinação de sementes em campo e laboratório e o florescimento de seis variedades locais de feijão comum e de quatro variedades de feijão-de-corda no Acre. Os dez materiais genéticos avaliados foram coletados no Acre no primeiro semestre de 2012. O teste de germinação em laboratório foi realizado usando 100 sementes mantidas em estufa a 250C por sete dias. No campo o experimento foi conduzido em delineamento em quatro blocos casualizados sendo contabilizada a germinação das plantas aos sete dias e o número de dias para florescimento. A germinação das sementes em campo foi superior ao teste de laboratório para maioria das variedades. O florescimento variou entre 23 e 56 dias dependendo da variedade

    Frequency of LCT -13910C>T single nucleotide polymorphism associated with adult-type hypolactasia/lactase persistence among Brazilians of different ethnic groups

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    <p>Abstract</p> <p>Background</p> <p>Adult-type hypolactasia, the physiological decline of lactase some time after weaning, was previously associated with the LCT -13910C>T polymorphism worldwide except in Africa. Lactase non-persistence is the most common phenotype in humans, except in northwestern Europe with its long history of pastoralism and milking. We had previously shown association of LCT -13910C>T polymorphism with adult-type hypolactasia in Brazilians; thus, we assessed its frequency among different Brazilian ethnic groups.</p> <p>Methods</p> <p>We investigated the ethnicity-related frequency of this polymorphism in 567 Brazilians [mean age, 42.1 ± 16.8 years; 157 (27.7%) men]; 399 (70.4%) White, 50 (8.8%) Black, 65 (11.5%) Brown, and 53 (9.3%) Japanese-Brazilian. DNA was extracted from leukocytes; LCT -13910C>T polymorphism was analyzed by PCR-restriction fragment length polymorphism.</p> <p>Results</p> <p>Prevalence of the CC genotype associated with hypolactasia was similar (57%) among White and Brown groups; however, prevalence was higher among Blacks (80%) and those of Japanese descent (100%). Only 2 (4%) Blacks had TT genotype, and 8 (16%) had the CT genotype. Assuming an association between CC genotype and hypolactasia, and CT and TT genotypes with lactase persistence, 356 (62.8%) individuals had hypolactasia and 211 (37.2%) had lactase persistence. The White and Brown groups had the same hypolactasia prevalence (~57%); nevertheless, was 80% among Black individuals and 100% among Japanese-Brazilians (<it>P </it>< 0.01).</p> <p>Conclusion</p> <p>The lactase persistence allele, LCT -13910T, was found in about 43% of both White and Brown and 20% of the Black Brazilians, but was absent among all Japanese Brazilians studied.</p

    Super-radiant light scattering from trapped Bose Einstein condensates

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    We propose a new formulation for atomic side mode dynamics from super-radiant light scattering of trapped atoms. A detailed analysis of the recently observed super-radiant light scattering from trapped bose gases [S. Inouye {\it et al.}, Science {\bf 285}, 571 (1999)] is presented. We find that scattered light intensity can exhibit both oscillatory and exponential growth behaviors depending on densities, pump pulse characteristics, temperatures, and geometric shapes of trapped gas samples. The total photon scattering rate as well as the accompanied matter wave amplification depends explicitly on atom number fluctuations in the condensate. Our formulation allows for natural and transparent interpretations of subtle features in the MIT data, and provides numerical simulations in good agreement with all aspects of the experimental observations.Comment: 24 pages,16 figures, submitted to Phys.Rev.

    Association of LEC and tnpA Helicobacter pylori genes with gastric cancer in a Brazilian population

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    <p>Abstract</p> <p>Background</p> <p><it>H. pylori </it>seroprevalence in Brazilians varies and is dependent on socioeconomic status, sanitation conditions and ethnicity; furthermore, <it>H. pylori </it>is not always associated with the incidence of gastric cancer, suggesting the role of more virulent strains. The purpose of this study was to analyze the association of more virulent <it>H. pylori </it>strains with gastric cancer.</p> <p>Methods</p> <p>DNA was extracted from gastric biopsies of thirty-four cases of gastric cancer (11 intestinal-type, 23 diffuse-type), and thirty-four of patients with endoscopic gastritis. The presence of <it>cag</it>PAI genes (<it>cagA</it>, <it>cagA </it>promoter, <it>cagE</it>, <it>cagM</it>, <it>tnpB</it>, <it>tnpA</it>, <it>cagT </it>and the left end of the <it>cag</it>II (LEC)) and <it>babA </it>were analyzed by PCR.</p> <p>Results</p> <p>Comparison of <it>H. pylori </it>isolates from gastric cancer and gastritis patients showed significant associations of <it>tnpA </it>and LEC with gastric cancer (73.5% [OR, 6.66; 95% CI, 2.30-19.25] and 58.8% [OR, 10.71; 95% CI, 3.07-37.28] of cases, respectively). Other <it>cag</it>PAI genes were detected in both groups at similar frequencies.</p> <p>Conclusions</p> <p><it>tnpA </it>and LEC of <it>H. pylori cag</it>PAI were associated with gastric cancer; nonetheless, these results were restricted within this group of patients and further studies are needed to confirm these results in a larger sample and determine their role in gastric carcinogenesis.</p

    The role of self-efficacy as an attribute of principals’ leadership effectiveness in K-12 private and public institutions in Lebanon

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    © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. The aim of this study is to explore the role of K-12 school principals’ self-efficacy as an attribute for their leadership effectiveness in Lebanon. The Norwegian principal self-efficacy scale (NPSES) instrument was translated into Arabic and used to collect quantitative data from participants. Internal consistency of factors within this study was checked (24 items; α = 0.73). By comparing private and public schools in Lebanon, all located in the governorate of Mount Lebanon, the researchers revealed the extent to which principals’ self-efficacy plays a role in their leadership. In addition, while no statistical difference was found between self-efficacy levels of private and public principals, females reported higher scores on the majority of the dimensions than their male counterparts in both types of schools. This study highlights the importance of the interaction effect of age and gender on self-efficacy levels. Moreover, it offers knowledge and practice to policy makers when recruiting principals or designing training programs. It also suggests the implementation of an in-house mentoring program to create school-school partnerships. Finally, this paper offers a platform for future researchers interested in principal self-efficacy in similar conflict-affected places with high economic depression. Limitations are further mentioned
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