INVESTIGATING THE ROLES OF MECHANORECEPTIVE CHANNELS IN TACTILE APPARENT MOTION PERCEPTION: A VIBROTACTILE STUDY

Tactile apparent motion (TAM) is a perceptual phenomenon in which consecutive presentation of multiple tactile stimuli creates an illusion of motion. Employing a novel tactile display device, the Latero, allowed us to investigate this. The current study focused on the Rapidly Adapting (RA) channel and Slowly Adapting I (SAI) channel on the index finger. The experiment implemented vibrotactile masking stimuli to target the mechanoreceptive channels with the goal of gaining better insight into the involvement of mechanoreceptive channels in the perception of TAM. Masking stimuli were used because previous studies have used them to differentiate between different channels; a certain masking stimulus will impact a mechanoreceptive channel more than others. The experiment began by measuring participants’ threshold for TAM stimuli by varying the stimulus intensity in a two-choice task (left vs right); participants received test trials consisting of TAM stimuli with 25 Hz and 6 Hz testing for the RA and SAI channels, respectively. Next, participants performed a series of test trials with vibrotactile masking stimuli that preceded the TAM stimuli mentioned above. The vibrotactile masking stimulus varied in duration (4 seconds vs 8 seconds) and intensity (two times vs three times the intensity of the TAM stimuli). The results suggest that there was no difference in accuracy when testing for the RA and SAI channels. The results also showed that the introduction of the masking stimuli significantly lowered accuracy. Overall, neither the RA nor the SAI channel may be uniquely involved in TAM perception. However, further improvement on the current design may aid in isolating each channel to help better understand the channel’s role in TAM perception

Hierarchical Group and Attribute-Based Access Control: Incorporating Hierarchical Groups and Delegation into Attribute-Based Access Control

Attribute-Based Access Control (ABAC) is a promising alternative to traditional models of access control (i.e. Discretionary Access Control (DAC), Mandatory Access Control (MAC) and Role-Based Access control (RBAC)) that has drawn attention in both recent academic literature and industry application. However, formalization of a foundational model of ABAC and large-scale adoption is still in its infancy. The relatively recent popularity of ABAC still leaves a number of problems unexplored. Issues like delegation, administration, auditability, scalability, hierarchical representations, etc. have been largely ignored or left to future work. This thesis seeks to aid in the adoption of ABAC by filling in several of these gaps. The core contribution of this work is the Hierarchical Group and Attribute-Based Access Control (HGABAC) model, a novel formal model of ABAC which introduces the concept of hierarchical user and object attribute groups to ABAC. It is shown that HGABAC is capable of representing the traditional models of access control (MAC, DAC and RBAC) using this group hierarchy and that in many cases it’s use simplifies both attribute and policy administration. HGABAC serves as the basis upon which extensions are built to incorporate delegation into ABAC. Several potential strategies for introducing delegation into ABAC are proposed, categorized into families and the trade-offs of each are examined. One such strategy is formalized into a new User-to-User Attribute Delegation model, built as an extension to the HGABAC model. Attribute Delegation enables users to delegate a subset of their attributes to other users in an off-line manner (not requiring connecting to a third party). Finally, a supporting architecture for HGABAC is detailed including descriptions of services, high-level communication protocols and a new low-level attribute certificate format for exchanging user and connection attributes between independent services. Particular emphasis is placed on ensuring support for federated and distributed systems. Critical components of the architecture are implemented and evaluated with promising preliminary results. It is hoped that the contributions in this research will further the acceptance of ABAC in both academia and industry by solving the problem of delegation as well as simplifying administration and policy authoring through the introduction of hierarchical user groups

Meteorites in the collections of Yale University

More than 400 localities where meteorites fell are recorded in this first list compiled in more than fifty years. The list combines the catalogues of two major collections housed in Yale University: the Peabody Museum Collection and the Carl Bosch Collection, which has been catalogued and is now being published for the first time

The Thin Ideal and Body Positivity: How Do Influencers Affect Female Instagram Users?

With the vast increase in social media use, there has also been an increase of exposure to body image ideals via photos shared online. Accordingly, it has become more important to understand the association between social media and how its users view their body image, as well as how social media users’ practices are affected by posted pictures. Therefore, this study employed three focus groups to explore young women’s perceptions of potential ideal images, how they compare themselves to these images, and how these ideas affect the practices used within their own Instagram accounts. An analysis of the qualitative data from 15 participants revealed three themes and one subtheme: admiration, but not participation; panel for posting with the subtheme three is a sweet spot ; and societal standards destroy self-image. The themes and subtheme represent the participants’ thoughts and actions surrounding social media images and practices carried out within their own Instagram accounts. Further, the analysis revealed a dual and paradoxical pattern related to the thin ideal as participants do not like the thin ideal, but want to fit into it, while also understanding that they should not model themselves after thin-ideal influencers. They also support the body positivity movement but are not comfortable posting body positive content. To manage the paradox, participants took actions to create an idealized Instagram account while also taking steps to avoid the thin ideal

A differential genome-wide transcriptome analysis : impact of cellular copper on complex biological processes like aging and development

The regulation of cellular copper homeostasis is crucial in biology. Impairments lead to severe dysfunctions and are known to affect aging and development. Previously, a loss-of-function mutation in the gene encoding the copper-sensing and copper-regulated transcription factor GRISEA of the filamentous fungus Podospora anserina was reported to lead to cellular copper depletion and a pleiotropic phenotype with hypopigmentation of the mycelium and the ascospores, affected fertility and increased lifespan by approximately 60% when compared to the wild type. This phenotype is linked to a switch from a copper-dependent standard to an alternative respiration leading to both a reduced generation of reactive oxygen species (ROS) and of adenosine triphosphate (ATP). We performed a genome-wide comparative transcriptome analysis of a wild-type strain and the copper-depleted grisea mutant. We unambiguously assigned 9,700 sequences of the transcriptome in both strains to the more than 10,600 predicted and annotated open reading frames of the P. anserina genome indicating 90% coverage of the transcriptome. 4,752 of the transcripts differed significantly in abundance with 1,156 transcripts differing at least 3-fold. Selected genes were investigated by qRT-PCR analyses. Apart from this general characterization we analyzed the data with special emphasis on molecular pathways related to the grisea mutation taking advantage of the available complete genomic sequence of P. anserina. This analysis verified but also corrected conclusions from earlier data obtained by single gene analysis, identified new candidates of factors as part of the cellular copper homeostasis system including target genes of transcription factor GRISEA, and provides a rich reference source of quantitative data for further in detail investigations. Overall, the present study demonstrates the importance of systems biology approaches also in cases were mutations in single genes are analyzed to explain the underlying mechanisms controlling complex biological processes like aging and development

Binocular Vision And The Kinematics Of Human Prehension

A series of experiments was devised to examine the contribution of binocular depth and distance cues to skilled reaching and grasping movements in humans. These movements were monitored using a high resolution opto-electronic recording device.;In the initial experiment, subjects reached out and grasped oblong blocks under conditions of either monocular or binocular vision. Kinematic analyses revealed that grasping movements made under monocular viewing conditions showed longer movement times, lower peak velocities, proportionately longer deceleration phases, and smaller grip apertures than movements made under binocular viewing. In short, subjects appeared to be underestimating the distance of objects (and as a consequence, their size) under monocular viewing.;The contribution of binocular visual feedback to the kinematics of human prehension was studied in two further experiments. In both experiments, the field of view of each eye could be independently controlled at various points during the trials by means of goggles fitted with liquid-crystal shutters. Subjects were required to reach out and grasp a target object, which varied in size and position from trial to trial. In one of these experiments, binocular vision was either available throughout the entire trial or the initial binocular view was replaced by a monocular view after the reaching movement had been initiated. When only monocular feedback was available, subjects showed a prolonged deceleration phase. In the other experiment, monocular vision was either available throughout a given trial or was replaced by binocular vision upon movement initiation. Subjects in this experiment also displayed a prolonged deceleration phase in the monocular feedback condition relative to their performance in the binocular feedback.;The final experiment examined the role that binocular information might play in the control of reaching movements directed at moving objects. No differences were found between a monocular and binocular viewing condition using this paradigm. It appears, then, that the moving targets provide adequate monocular depth and direction information (on the basis of optic flow) for the control of skilled interceptive movements directed at them.;The nature of visual and visuomotor representations is discussed. It is argued that the representation of depth and distance in the visual domain is rather different than the representation of such attributes in the visuomotor domain. Further, it is suggested that separate neural substrates subserve these two fundamentally different processes

TMS-induced Neural Noise in Sensory Cortex Interferes with Short-term Memory Storage in Prefrontal Cortex

In a previous study, Harris et al. (2002) found disruption of vibrotactile short-term memory after applying single-pulse transcranial magnetic stimulation (TMS) to primary somatosensory cortex (SI) early in the maintenance period, and suggested that this demonstrated a role for SI in vibrotactile memory storage. While such a role is compatible with recent suggestions that sensory cortex is the storage substrate for working memory, it stands in contrast to a relatively large body of evidence from human EEG and single-cell recording in primates that instead points to prefrontal cortex as the storage substrate for vibrotactile memory. In the present study, we use computational methods to demonstrate how Harris et al.\u27s results can be reproduced by TMS-induced activity in sensory cortex and subsequent feedforward interference with memory traces stored in prefrontal cortex, thereby reconciling discordant findings in the tactile memory literature

INVESTIGATING THE ROLES OF MECHANORECEPTIVE CHANNELS IN TACTILE APPARENT MOTION PERCEPTION: A VIBROTACTILE STUDY

Tactile apparent motion (TAM) is a perceptual phenomenon in which consecutive presentation of multiple tactile stimuli creates an illusion of motion. Employing a novel tactile display device, the Latero, allowed us to investigate this. The current study focused on the Rapidly Adapting (RA) channel and Slowly Adapting I (SAI) channel on the index finger. The experiment implemented vibrotactile masking stimuli to target the mechanoreceptive channels with the goal of gaining better insight into the involvement of mechanoreceptive channels in the perception of TAM. Masking stimuli were used because previous studies have used them to differentiate between different channels; a certain masking stimulus will impact a mechanoreceptive channel more than others. The experiment began by measuring participants’ threshold for TAM stimuli by varying the stimulus intensity in a two-choice task (left vs right); participants received test trials consisting of TAM stimuli with 25 Hz and 6 Hz testing for the RA and SAI channels, respectively. Next, participants performed a series of test trials with vibrotactile masking stimuli that preceded the TAM stimuli mentioned above. The vibrotactile masking stimulus varied in duration (4 seconds vs 8 seconds) and intensity (two times vs three times the intensity of the TAM stimuli). The results suggest that there was no difference in accuracy when testing for the RA and SAI channels. The results also showed that the introduction of the masking stimuli significantly lowered accuracy. Overall, neither the RA nor the SAI channel may be uniquely involved in TAM perception. However, further improvement on the current design may aid in isolating each channel to help better understand the channel’s role in TAM perception

e-Social work and digital society: re-conceptualizing approaches, practices and technologies

Introduction The digitalisation of society is changing our behaviour, our institutions and the helping professions, among them social work. Adapting to this new environment is one of the main challenges facing social work as both a scientific discipline and a helping profession. This new technological environment is not only impacting on teaching methods in higher education, but also diagnostic and social intervention techniques. At the same time, processes of social exclusion are taking place in the digital domain that require social workers to become more specialised. In introducing this themed issue of the journal, we examine how social work can benefit from e-social work to adapt to the new demands and needs of today's digital society..

Las organizaciones no gubernamentales para el desarrollo (ONGD) en España

We present a study of the Non-governmental Organisations for the Development (NGOD) Spanish, members of Coordinator of NGOD- Spain (CNGOD-AND). These organisations represent a set Consolidated within sector wider of the Non-profít Organisations. They have gone from the social invisibility to the growing presence in the media and in the imaginary of the society. They have been Consolidated as social actors and as political actors. In fact, from a sociological point of view they are considered as a fundamental part of the new social movements. Also, they are economic agents, since they manage tens of million of pesetas around the beginning of the eighties and 40 billion in the year 1996. We analyse also the structural transformation that they have experimented in the last five years: contracted personnel increase, number of volunteer, number of Services offer and International presence.En este artículo se analizan las Organizaciones No Gubernamentales para el Desarrollo (ONGD) españolas, federadas en el marco de la Coordinadora de ONGD-España (CONGD-E). Estas organizaciones representan un conjunto consolidado dentro del sector más amplio de las Organizaciones No Lucrativas. Han pasado de la invisibilidad social, a la presencia creciente en los medios de comunicación y en el imaginario de la sociedad. Se han consolidado como actores sociales y como actores políticos. De hecho, desde un punto de vista sociológico son consideradas como una parte fundamental de los llamados nuevos movimientos sociales. Asimismo, también son agentes económicos que han pasado de la gestión de poco más de unas decenas de millones de pesetas a comienzos de los años ochenta, a unos ingresos de 40.000 millones en el año 1996. Junto a esto hay que destacar también la transformación estructural que han experimentado: incremento de personal contratado, de voluntariado, de oferta de servicios, de presencia internacional