1,720,956 research outputs found
Flywheel–infinitely variable transmissions for energy recovery capabilities in artificial knee joints
No full textIn this work, we present a novel architecture of the flywheel–infinitely variable transmission (F-IVT) actuator with increased energy saving performance. The F-IVT is an actuator for artificial knee joints with energy recovery capabilities. It uses a flywheel and an IVT with the purpose of storing and releasing energy and stabilizing the motor working point. The architecture proposed herein, named “linear F-IVT”, is compared with the rotating F-IVT and with the clutchable-series elastic actuator, through a model-based approach. By simulating the operation of these actuators in walking at different speed and stairs climbing of different inclination, the linear F-IVT results to be the most effective in reducing the peak of electric power and motor torque, also achieving a reduction of the electric energy demanded. These results suggest the possibility to achieve a significant motor downsizing, possibly leading to the development of a lightweight actuator to improve the portability and the operating range of wearable robots for lower limbs. Abbreviations: BS: ball screw; C-SEA: clutchable - series elastic actuator; CVT: continuously variable transmission; F-IVT: flywheel–infinitely variable transmission; HD: harmonic drive; IVT: infinitely variable transmissio
Antihypertensive and neuroprotective effects of catestatin in spontaneously hypertensive rats: interaction with GABAergic transmission in amygdala and brainstem.
No full textThe chromogranin A-derived peptide catestatin (CST) exerts sympathoexcitatory and hypertensive effects when microinjected into the rostral ventrolateral medulla (RVLM: excitatory output); it exhibits sympathoinhibitory and antihypertensive effects when microinjected into the caudal ventrolateral medulla (CVLM: inhibitory output) of vagotomized normotensive rats. Here, continuous infusion of CST into the central amygdalar nucleus (CeA) of spontaneously hypertensive rats (SHRs) for 15 days resulted in a marked decrease of blood pressure (BP) in 6-month- (by 37 mm Hg) and 9-month- (by 65 mm Hg)old rats. Whole-cell patch-clamp recordings on pyramidal CeA neurons revealed that CST increased both spontaneous inhibitory postsynaptic current (sIPSC) amplitude plus frequency, along with reductions of sIPSC rise time and decay time. Inhibition of GABAA receptors (GABAARs) by bicuculline completely abolished CST-induced sIPSC, corroborating that CST signals occur through this major neuroreceptor complex. Hypertension is a major risk factor for cerebrovascular diseases, leading to vascular dementia and neurodegeneration. We found a marked neurodegeneration in the amygdala and brainstem of 9-month-old SHRs, while CST and the GABAAR agonist Muscimol provided significant neuroprotection. Enhanced phosphorylation of Akt and ERK accounted for these neuroprotective effects through anti-inflammatory and anti-apoptotic activities. Overall our results point to CST exerting potent antihypertensive and neuroprotective effects plausibly via a GABAergic output, which constitute a novel therapeutic measure to correct defects in blood flow control in disorders such as stroke and Alzheimer's disease
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Antihypertensive and neuroprotective effects of catestatin in spontaneously hypertensive rats: Interaction with GABAergic transmission in amygdala and brainstem.
No full textThe chromogranin A-derived peptide catestatin
(CST) exerts sympathoexcitatory and hypertensive effects
when microinjected into the rostral ventrolateral medulla
(RVLM: excitatory output); it exhibits sympathoinhibitory
and antihypertensive effects when microinjected into the
caudal ventrolateral medulla (CVLM: inhibitory output) of
vagotomized normotensive rats. Here, continuous infusion
of CST into the central amygdalar nucleus (CeA) of spontaneously
hypertensive rats (SHRs) for 15 days resulted in a
marked decrease of blood pressure (BP) in 6-month- (by
37 mmHg) and 9-month- (by 65 mmHg)old rats. Whole-cell
patch-clamp recordings on pyramidal CeA neurons revealed
that CST increased both spontaneous inhibitory postsynaptic
current (sIPSC) amplitude plus frequency, along with
reductions of sIPSC rise time and decay time. Inhibition of
GABAA receptors (GABAARs) by bicuculline completely
abolished CST-induced sIPSC, corroborating that CST signals
occur through this major neuroreceptor complex.
Hypertension is a major risk factor for cerebrovascular diseases,
leading to vascular dementia and neurodegeneration.
We found a marked neurodegeneration in the amygdala and
brainstem of 9-month-old SHRs, while CST and the GABAAR agonist Muscimol provided significant neuroprotection.
Enhanced phosphorylation of Akt and ERK accounted for
these neuroprotective effects through anti-inflammatory
and anti-apoptotic activities. Overall our results point to
CST exerting potent antihypertensive and neuroprotective
effects plausibly via a GABAergic output, which constitute
a novel therapeutic measure to correct defects in blood flow
control in disorders such as stroke and Alzheimer’s disease
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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