67 research outputs found
A deficit of spatial remapping in constructional apraxia after right-hemisphere stroke
This Article is provided by the Brunel Open Access Publising Fund - Copyright @ 2010 Oxford University PressConstructional apraxia refers to the inability of patients to copy accurately drawings or three-dimensional constructions. It is a common disorder after right parietal stroke, often persisting after initial problems such as visuospatial neglect have resolved. However, there has been very little experimental investigation regarding mechanisms that might contribute to the syndrome. Here, we examined whether a key deficit might be failure to integrate visual information correctly from one fixation to the next. Specifically, we tested whether this deficit might concern remapping of spatial locations across saccades. Right-hemisphere stroke patients with constructional apraxia were compared to patients without constructional problems and neurologically healthy controls. Participants judged whether a pattern shifted position (spatial task) or changed in pattern (non-spatial task) across two saccades, compared to a control condition with an equivalent delay but without intervening eye movements. Patients with constructional apraxia were found to be significantly impaired in position judgements with intervening saccades, particularly when the first saccade of the sequence was to the right. The importance of these remapping deficits in constructional apraxia was confirmed through a highly significant correlation between saccade task performance and constructional impairment on standard neuropsychological tasks. A second study revealed that even single saccades to the right can impair constructional apraxia patientsā perception of location shifts. These data are consistent with the view that rightward eye movements result in loss of remembered spatial information from previous fixations, presumably due to constructional apraxia patientsā damage to the right-hemisphere regions involved in remapping locations across saccades. These findings provide the first evidence for a deficit in remapping visual information across saccades underlying right-hemisphere constructional apraxia.European Commission Marie Curie Intra-European Fellowship (011457 to C.R.) and a Wellcome Trust Senior Fellowship (to M.H.)
Model Averaging in Markov-Switching Models: Predicting National Recessions with Regional Data
Coastal high-frequency radars in the Mediterranean ??? Part 2: Applications in support of science priorities and societal needs
International audienceThe Mediterranean Sea is a prominent climate-change hot spot, with many socioeconomically vital coastal areas being the most vulnerable targets for maritime safety, diverse met-ocean hazards and marine pollution. Providing an unprecedented spatial and temporal resolution at wide coastal areas, high-frequency radars (HFRs) have been steadily gaining recognition as an effective land-based remote sensing technology for continuous monitoring of the surface circulation, increasingly waves and occasionally winds. HFR measurements have boosted the thorough scientific knowledge of coastal processes, also fostering a broad range of applications, which has promoted their integration in coastal ocean observing systems worldwide, with more than half of the European sites located in the Mediterranean coastal areas. In this work, we present a review of existing HFR data multidisciplinary science-based applications in the Mediterranean Sea, primarily focused on meeting end-user and science-driven requirements, addressing regional challenges in three main topics: (i) maritime safety, (ii) extreme hazards and (iii) environmental transport process. Additionally, the HFR observing and monitoring regional capabilities in the Mediterranean coastal areas required to underpin the underlying science and the further development of applications are also analyzed. The outcome of this assessment has allowed us to provide a set of recommendations for future improvement prospects to maximize the contribution to extending science-based HFR products into societally relevant downstream services to support blue growth in the Mediterranean coastal areas, helping to meet the UN's Decade of Ocean Science for Sustainable Development and the EU's Green Deal goals
Coastal high-frequency radars in the Mediterranean ??? Part 1: Status of operations and a framework for future development
Due to the semi-enclosed nature of the Mediterranean
Sea, natural disasters and anthropogenic activities impose
stronger pressures on its coastal ecosystems than in any
other sea of the world.With the aim of responding adequately
to science priorities and societal challenges, littoral waters
must be effectively monitored with high-frequency radar
(HFR) systems. This land-based remote sensing technology
can provide, in near-real time, fine-resolution maps of the
surface circulation over broad coastal areas, along with reliable
directional wave and wind information. The main goal
of this work is to showcase the current status of the Mediterranean
HFR network and the future roadmap for orchestrated
actions. Ongoing collaborative efforts and recent progress of
this regional alliance are not only described but also connected
with other European initiatives and global frameworks,
highlighting the advantages of this cost-effective instrument
for the multi-parameter monitoring of the sea state.
Coordinated endeavors between HFR operators from different
multi-disciplinary institutions are mandatory to reach a
mature stage at both national and regional levels, striving to
do the following: (i) harmonize deployment and maintenance
practices; (ii) standardize data, metadata, and quality control
procedures; (iii) centralize data management, visualization,
and access platforms; and (iv) develop practical applications
of societal benefit that can be used for strategic planning and
informed decision-making in the Mediterranean marine environment.
Such fit-for-purpose applications can serve for
search and rescue operations, safe vessel navigation, tracking
of marine pollutants, the monitoring of extreme events,
the investigation of transport processes, and the connectivity
between offshore waters and coastal ecosystems. Finally, future
prospects within the Mediterranean framework are discussed
along with a wealth of socioeconomic, technical, and
scientific challenges to be faced during the implementatio
Balancing Flexibility and Discipline in Microfinance: Innovative Financial Products That Benefit Clients and Service Providers
The Effect of Volatile Anesthetics on Respiratory System Resistance in Patients with Chronic Obstructive Pulmonary Disease
- ā¦