The neural basis of centre-surround interactions in visual motion processing

Perception of a moving visual stimulus can be suppressed or enhanced by surrounding context in adjacent parts of the visual field. We studied the neural processes underlying such contextual modulation with fMRI. We selected motion selective regions of interest (ROI) in the occipital and parietal lobes with sufficiently well defined topography to preclude direct activation by the surround. BOLD signal in the ROIs was suppressed when surround motion direction matched central stimulus direction, and increased when it was opposite. With the exception of hMT+/V5, inserting a gap between the stimulus and the surround abolished surround modulation. This dissociation between hMT+/V5 and other motion selective regions prompted us to ask whether motion perception is closely linked to processing in hMT+/V5, or reflects the net activity across all motion selective cortex. The motion aftereffect (MAE) provided a measure of motion perception, and the same stimulus configurations that were used in the fMRI experiments served as adapters. Using a linear model, we found that the MAE was predicted more accurately by the BOLD signal in hMT+/V5 than it was by the BOLD signal in other motion selective regions. However, a substantial improvement in prediction accuracy could be achieved by using the net activity across all motion selective cortex as a predictor, suggesting the overall conclusion that visual motion perception depends upon the integration of activity across different areas of visual cortex

Developing a discourse for CPD leadership in the secondary school sector in England

This study was founded upon an assumption that the discourses of leadership and Continuing Professional Development (CPD) in England are different, and that leading CPD in England is complex and difficult to manage. The overall goal was first to develop a shared understanding of concepts of CPD leadership which underpin the complexity, and second to assist overcoming the confusion. Both the assumption and the stated goal emanate from the researcher’s own professional position. The researcher is professionally active in the field, as a provider of CPD, and also as a representative of the University sector. As chair of the Universities’ Council for the Education of Teachers (UCET) CPD committee, the researcher has lobbied for academically accredited CPD. This presupposes a respect for teachers’ criticality and a reflective approach to Government proposed policy. The work examines policies and practices of CPD since 2000. Significant organisations (e.g. General Teaching Council for England, Training and Development Agency for Schools, National College of Leadership for Schools and Children’s Services) have based their work on a number of concepts which have contributed to a confusion and complexity for leaders of CPD tasked with shaping practice. The initial literature review showed how concepts associated with CPD leadership are emerging, and that therefore any research could not be based upon a static focus. The study explored concepts of educational leadership, noting the emphasis on individual styles, behaviours and performance of leaders. This analysis contrasted with findings that CPD is more focussed on the collective effort of professionals. The study is based upon professionally focussed research. Findings varied according to different stakeholder groups’ attitudes and tacit understandings. The methodology adopted was essentially qualitative and consisted of approaches and techniques associated with phenomenology, action research and grounded theory. Although the term ‘discourse’ is frequently used, it is in the sense of ‘discourse analysis’, rather than of ‘discourse theory’. Outcomes of the work were the identification of four dimensions, which may be seen to drive CPD leadership, and which served to provide an underpinning framework to help the analysis of the research. The uncovering of nine variables, which determine the emphasis contained within different approaches to CPD, served as finer detail to aid CPD leaders. These perspectives were developed into a survey tool, and served as stimuli for interviews. Use of the survey and interviews provided data sets for close scrutiny, leading to a visual representation of different stakeholder perspectives, and indications of how and why each group differed from others. The findings also showed areas of agreement and shared understanding. The work ends with a consideration of how identifying the concepts and perspectives underpinning a CPD initiative can assist CPD leaders in shaping their behaviour and practice

Reevaluating evaluative conditioning: A nonassociative explanation of conditioning effects in the visual evaluative conditioning paradigm

In 2 studies, the authors investigated whether evaluative conditioning (EC) is an associative phenomenon. Experiment 1 compared a standard EC paradigm with nonpaired and no-treatment control conditions. EC effects were obtained only when the conditioned stimulus (CS) and unconditioned stimulus (UCS) were rated as perceptually similar. However, similar EC effects were obtained in both control groups. An earlier failure to obtain EC effects was reanalyzed in Experiment 2. Conditioning-like effects were found when comparing a CS with the most perceptually similar UCSs used in the procedure but not when analyzing a CS rating with respect to the UCS with which it was paired during conditioning. The implications are that EC effects found in many studies are not due to associative learning and that the special characteristics of EC (conditioning without awareness and resistance to extinction) are probably nonassociative artifacts of the EC paradigm

Experimental evidence for radiative attachment in astrochemistry from electron attachment to NCCCCN

Electron attachment to NCCCCN, dicyanoacetylene (2-butynedinitrile), has been observed. Metastable parent anions, NCCCCN_∗, with microsecond or longer lifetimes are formed close to 0 eV electron energy with a cross section of ≥0.25 2. The stability of NCCCCN suggests that radiative attachment to NCCCCN and similar _∗ °A linear carbon chain molecules may be an important mechanism for the formation of negatively charged molecular ions in astrophysical environments. CCCN_ and CN_ fragment anions are formed at ∼3 and ∼6 eV

A climatically-derived global soil moisture data set for use in the GLAS atmospheric circulation model seasonal cycle experiment

Algorithms for point interpolation and contouring on the surface of the sphere and in Cartesian two-space are developed from Shepard's (1968) well-known, local search method. These mapping procedures then are used to investigate the errors which appear on small-scale climate maps as a result of the all-too-common practice of of interpolating, from irregularly spaced data points to the nodes of a regular lattice, and contouring Cartesian two-space. Using mean annual air temperatures field over the western half of the northern hemisphere is estimated both on the sphere, assumed to be correct, and in Cartesian two-space. When the spherically- and Cartesian-approximted air temperature fields are mapped and compared, the magnitudes (as large as 5 C to 10 C) and distribution of the errors associated with the latter approach become apparent

On the Production of Homeland Security Under True Uncertainty

Homeland security against possible terrorist attacks involves making decisions under true uncertainty. Not only are we ignorant of the form, place, and time of potential terrorist attacks, we are also largely ignorant of the likelihood of these attacks. In this paper, we conceptualize homeland security under true uncertainty as society’s immunity to unacceptable losses. We illustrate and analyze the consequences of this notion of security with a simple model of allocating a fixed budget for homeland security to defending the pathways through which a terrorist may launch an attack and to mitigating the damage from an attack that evades this defense. In this problem, immunity is the range of uncertainty about the likelihood of an attack within which the actual expected loss will not exceed some critical value. We analyze the allocation of a fixed homeland security budget to defensive and mitigative efforts to maximize immunity to alternative levels of expected loss. We show that the production of homeland security involves a fundamental trade-off between immunity and acceptable loss; that is, for fixed resources that are optimally allocated to defense and mitigation, increasing immunity requires accepting higher expected losses, and reducing acceptable expected losses requires lower immunity. Greater investments in homeland security allow society to increase its immunity to a particular expected loss, reduce the expected losses to which we are immune while holding the degree of immunity constant, or some combination of increased immunity to a lower critical expected loss.Homeland Security, Terrorism, True Uncertainty

Satellite versus ground-based estimates of burned area: a comparison between MODIS based burned area and fire agency reports over North America in 2007

North American wildfire management teams routinely assess burned area on site during firefighting campaigns; meanwhile, satellite observations provide systematic and global burned-area data. Here we compare satellite and ground-based daily burned area for wildfire events for selected large fires across North America in 2007 on daily timescales. In a sample of 26 fires across North America, we found the Global Fire Emissions Database Version 4 (GFED4) estimated about 80% of the burned area logged in ground-based Incident Status Summary (ICS-209) over 8-day analysis windows. Linear regression analysis found a slope between GFED and ICS-209 of 0.67 (with R = 0.96). The agreement between these data sets was found to degrade at short timescales (from R = 0.81 for 4-day to R = 0.55 for 2-day). Furthermore, during large burning days (> 3000 ha) GFED4 typically estimates half of the burned area logged in the ICS-209 estimates