1,413 research outputs found
Categorization of compensatory motions in transradial myoelectric prosthesis users
Background: Prosthesis users perform various compensatory motions to accommodate for the loss of the hand and wrist as well as the reduced functionality of a prosthetic hand.
Objectives: Investigate different compensation strategies that are performed by prosthesis users.
Study Design: Comparative analysis
Methods: 20 able-bodied subjects and 4 prosthesis users performed a set of bimanual activities. Movements of the trunk and head were recorded using a motion capture system, and a digital video recorder. Clinical motion angles were calculated to assess the compensatory motions made by the prosthesis users. The video recording also assisted in visually identifying the compensations.
Results: Compensatory motions by the prosthesis users were evident in the tasks performed (slicing and stirring activities) as compared to the benchmark of able-bodied subjects. Compensations took the form of a measured increase in range of motion, an observed adoption of a new posture during task execution, and pre-positioning of items in the workspace prior to initiating a given task.
Conclusion: Compensatory motions were performed by prosthesis users during the selected tasks. These can be categorized into three different types of compensations
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ADC Nonlinearity Correction for the Majorana Demonstrator
Imperfections in analog-to-digital conversion (ADC) cannot be ignored when signal digitization requirements demand both wide dynamic range and high resolution, as is the case for the Majorana Demonstrator 76Ge neutrinoless double-beta decay search. Enabling the experiment's high-resolution spectral analysis and efficient pulse shape discrimination required careful measurement and correction of ADC nonlinearities. A simple measurement protocol was developed that did not require sophisticated equipment or lengthy data-taking campaigns. A slope-dependent hysteresis was observed and characterized. A correction applied to digitized waveforms prior to signal processing reduced the differential and integral nonlinearities by an order of magnitude, eliminating these as dominant contributions to the systematic energy uncertainty at the double-beta decay Q value
Different atmospheric moisture divergence responses to extreme and moderate El Niños
On seasonal and inter-annual time scales, vertically integrated moisture divergence provides a useful measure of the tropical atmospheric hydrological cycle. It reflects the combined dynamical and thermodynamical effects, and is not subject to the limitations that afflict observations of evaporation minus precipitation. An empirical orthogonal function (EOF) analysis of the tropical Pacific moisture divergence fields calculated from the ERA-Interim reanalysis reveals the dominant effects of the El Niño-Southern Oscillation (ENSO) on inter-annual time scales. Two EOFs are necessary to capture the ENSO signature, and regression relationships between their Principal Components and indices of equatorial Pacific sea surface temperature (SST) demonstrate that the transition from strong La Niña through to extreme El Niño events is not a linear one. The largest deviation from linearity is for the strongest El Niños, and we interpret that this arises at least partly because the EOF analysis cannot easily separate different patterns of responses that are not orthogonal to each other. To overcome the orthogonality constraints, a self-organizing map (SOM) analysis of the same moisture divergence fields was performed. The SOM analysis captures the range of responses to ENSO, including the distinction between the moderate and strong El Niños identified by the EOF analysis. The work demonstrates the potential for the application of SOM to large scale climatic analysis, by virtue of its easier interpretation, relaxation of orthogonality constraints and its versatility for serving as an alternative classification method. Both the EOF and SOM analyses suggest a classification of “moderate” and “extreme” El Niños by their differences in the magnitudes of the hydrological cycle responses, spatial patterns and evolutionary paths. Classification from the moisture divergence point of view shows consistency with results based on other physical variables such as SST
Beyond Volume: The Impact of Complex Healthcare Data on the Machine Learning Pipeline
From medical charts to national census, healthcare has traditionally operated
under a paper-based paradigm. However, the past decade has marked a long and
arduous transformation bringing healthcare into the digital age. Ranging from
electronic health records, to digitized imaging and laboratory reports, to
public health datasets, today, healthcare now generates an incredible amount of
digital information. Such a wealth of data presents an exciting opportunity for
integrated machine learning solutions to address problems across multiple
facets of healthcare practice and administration. Unfortunately, the ability to
derive accurate and informative insights requires more than the ability to
execute machine learning models. Rather, a deeper understanding of the data on
which the models are run is imperative for their success. While a significant
effort has been undertaken to develop models able to process the volume of data
obtained during the analysis of millions of digitalized patient records, it is
important to remember that volume represents only one aspect of the data. In
fact, drawing on data from an increasingly diverse set of sources, healthcare
data presents an incredibly complex set of attributes that must be accounted
for throughout the machine learning pipeline. This chapter focuses on
highlighting such challenges, and is broken down into three distinct
components, each representing a phase of the pipeline. We begin with attributes
of the data accounted for during preprocessing, then move to considerations
during model building, and end with challenges to the interpretation of model
output. For each component, we present a discussion around data as it relates
to the healthcare domain and offer insight into the challenges each may impose
on the efficiency of machine learning techniques.Comment: Healthcare Informatics, Machine Learning, Knowledge Discovery: 20
Pages, 1 Figur
On the power and the systematic biases of the detection of chromosomal inversions by paired-end genome sequencing
One of the most used techniques to study structural variation at a genome level is paired-end mapping (PEM). PEM has the advantage of being able to detect balanced events, such as inversions and translocations. However, inversions are still quite difficult to predict reliably, especially from high-throughput sequencing data. We simulated realistic PEM experiments with different combinations of read and library fragment lengths, including sequencing errors and meaningful base-qualities, to quantify and track down the origin of false positives and negatives along sequencing, mapping, and downstream analysis. We show that PEM is very appropriate to detect a wide range of inversions, even with low coverage data. However, % of inversions located between segmental duplications are expected to go undetected by the most common sequencing strategies. In general, longer DNA libraries improve the detectability of inversions far better than increments of the coverage depth or the read length. Finally, we review the performance of three algorithms to detect inversions -SVDetect, GRIAL, and VariationHunter-, identify common pitfalls, and reveal important differences in their breakpoint precisions. These results stress the importance of the sequencing strategy for the detection of structural variants, especially inversions, and offer guidelines for the design of future genome sequencing projects
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How Emerging Organizations Take Form: The Role of Imprinting and Values in Organizational Bricolage
We examine how emerging organizations acquire shape by drawing on multiple organizational forms, a process we call organizational bricolage. Studying Indymedia London, a grassroots media collective, we propose a grounded theory of organizational bricolage that identifies how various types of organizational forms are selected and how they are instantiated into the organization. Whereas extant research has emphasized imprinting as a primary mechanism shaping newly founded organizations, we point to the additional role of organizational values. Emerging organizations augment their imprinted forms by using ancillary forms aligned with their organizational values and reinforce their core features by differentiating themselves from antagonistic forms that conflict with their values. We contribute to the literature on organizational formation by developing a process model that details how imprinted forms are subsequently modified. Moreover, we extend theories of bricolage by specifying the limits to the relative arbitrariness of bricolage as an activity, and we contribute to the study of organizational values by suggesting that they act as a focusing device shaping organizational structure
Psychologists’ dilemmas in career counselling practice
In this study, we explored main dilemmas psychologists face in career
counselling in two main professional settings: employment and education. Participants
included 24 experienced Portuguese psychologists, working in employment
(n = 14) and educational (n = 10) settings. We used consensual qualitative
research to conduct and analyse semi-structured interviews. Results revealed
dilemmas’ in five domains: neutrality, assessment, dual loyalty, role boundaries, and
confidentiality, with the typical dilemma in the domain of neutrality. Differences
between groups were found in the domains of dual loyalty and role boundaries.Dans cette étude, nous avons exploré les principaux dilemmes rencontrés
par les psychologues dans le conseil en orientation dans deux milieux professionnels
centraux: le placement et l’éducation. Parmi les participants figuraient 24 psychologues
portugais expérimentés travaillant dans des contextes de placement (n = 14)
et d’éducation (n = 10). Nous avons utilisé la recherche qualitative consensuelle
pour mener et analyser les entretiens semi-structurés. Les re´sultats ont révé lé des
dilemmes dans cinq domaines: la neutralité, l’évaluation, la double loyauté, les
limites du rôle, et la confidentialité, avec le dilemme typique dans le domaine de la
neutralité. Les différences entre les groupes ont été identifiees dans les domaines de
la double loyauté et les limites du rôle.In dieser Studie untersuchten wir die hauptsä chlichen Dilemmata, mit denen Psychologen in der Berufsberatung in zwei wesentlichen professionellen
Einrichtungen konfrontiert sind: Beruf und Bildung. Zu den Teilnehmern geho
¨rten 24 erfahrene portugiesische Psychologen, die in Einrichtungen von Beruf
(n = 14) und Bildung (n = 10) arbeiteten. Wir verwendeten einvernehmliche
qualitative Forschung um semi-strukturierte Interviews durchzufu¨hren und zu
analysieren. Die Ergebnisse zeigten Dilemmata in fünf Bereichen: Neutralität,
Beurteilung, doppelte Loyalität, Rollengrenzen und Vertraulichkeit, mit dem
typischen Dilemma in der Domäne der Neutralität. Unterschiede zwischen den
Gruppen wurden in den Bereichen der doppelten Loyalität und Rollengrenzen
gefunden
Refined clothespin relocation test and assessment of motion
Background: Advancements in upper limb prosthesis design have focused on providing increased degrees of freedom for the end effector through multiple articulations of a prosthetic hand, wrist and elbow. Measuring improvement in patient function with these devices requires development of appropriate assessment tools.
Objectives: This study presents a refined clothespin relocation test for measuring performance and assessing compensatory motion between able-bodied subjects and subjects with upper limb impairments.
Study Design: Comparative analysis
Methods: Trunk and head motions of 13 able-bodied subjects who performed the refined clothespin relocation test were compared to the motion of a transradial prosthesis user with a single degree of freedom hand.
Results: There were observable differences between the prosthesis user and the able-bodied group. The assessment used provided a clear indication of the differences in motion through analysis of compensatory motion.
Conclusion: The refined clothespin relocation test provides additional benefits over the standard clothespin assessment and makes identification of compensatory motions easily identifiable to the researcher. While this paper establishes the method for the new assessment, further validation will need to be performed with more users
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Results of the MAJORANA DEMONSTRATOR's Search for Double-Beta Decay of 76Ge to Excited States of 76Se
The MAJORANA DEMONSTRATOR is searching for double-beta decay of 76Ge to excited states (E.S.) in 76Se using a modular array of high purity Germanium detectors. 76Ge can decay into three E.S.s of 76Se. The E.S. decays have a clear event signature consisting of a ββ-decay with the prompt emission of one or two γ-rays, resulting in with high probability in a multi-site event. The granularity of the DEMONSTRATOR detector array enables powerful discrimination of this event signature from backgrounds. Using 21.3 kg-y of isotopic exposure, the DEMONSTRATOR has set world leading limits for each E.S. decay, with 90% CL lower half-life limits in the range of (0.56 2.1) ⋅ 1024 y. In particular, for the 2v transition to the first 0+ E.S. of 76Se, a lower half-life limit of 0.68 ⋅ 1024 at 90% CL was achieved
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