THE PRIMING OF VISUAL FEATURE INTEGRATION AND ILLUSORY CONJUNCTIONS

Whether non-spatial previewing can interact with the process of integrating visual features and thereby affect the formation of illusory conjunctions was studied. A series of ten experiments were undertaken that employed methods borrowed from the illusory conjunction and visual previewing paradigms. Participants reported the identities of two briefly presented target objects. Preview stimuli were presented prior to the to-be-reported target stimuli. The preview objects and target objects were colour-filled geometric shapes. The effects of two types of non-spatial previewing were investigated; feature previewing and conjunction previewing. In feature previewing the preview stimuli were congruent or incongruent with one of the target stimuli on a single stimulus dimension. The results suggest that feature previewing does not affect the production of illusory conjunctions. In conjunction previewing the preview display contains an object composed of two features that also appear in the subsequent target display. A congruent conjunction preview display contains an object that is identical to one of the target objects. An incongruent conjunction preview display contains an object composed of a colour and a shape that appear in different target objects. The results suggest that incongruent conjunction previews cause more illusory conjunctions than congruent conjunction previews do. Conjunction previews appear to priming of the process of visual feature integration. Alternative explanations of the results were ruled out by subsequent experiments. The finding of the conjunction preview effect has implications for the current theories of visual feature integration and illusory conjunctions; e.g., feature integration theory (Treisman 1990; Treisman & Gelade) and location uncertainty theory (Ashby, Prinzmetal, Ivry & Maddox, 1996; Prinzmetal &. Keysar, 1989)

Sports’ Relationship with Reaction Time and Working Memory Capacity

37 pagesThis paper examines different relationships between reaction time and working memory capacity in athletes and non-athletes. It also examines relationships between reaction time and working memory with different types of athletes sorted by time spent playing sports and the sport the athlete plays. This experiment found evidence that supports current theories that athletes have faster reaction times than non-athletes. It found no relationship between working memory capacity and athletes, however certain sports showed potential. Athletes with more years of sports experience performed worse on each task, although most were not significant. Finally, Basketball players were found to have significantly faster reaction time than non-athletes and Football players significantly outperformed non-athletes on one working memory task. Soccer and Volleyball players all had higher average mean scores on the three working memory tasks than non-athletes. However these were not significant. Football players also outperformed non-athletes on two of the three working memory tasks, one of which was significant and barely underperformed on the other task. These findings indicate there might be a potential for athletes from these three sports to have higher working memory capacity than non-athletes. This study struggles due to small sample sizes for specific sports. Future studies should aim to recruit a set amount of athletes from each different sport to prevent this issue

The impact of soft errors in logic and its commercialisation in ARM IP

The significance of soft errors in logic has grown because of reduced memory vulnerability and the shrinking dimensions of semiconductor technology coupled with the increasing amount of logic integrated into a chip. Consequently, some of ARM’s customers are concerned about how soft errors on the bus interconnect will affect the dependability of their systems, since the interconnect is a critical hub of communication in a SoC and represents a substantial and growing amount of logic. With the rising complexity of their systems, the interconnect will become larger and more complex in the future, adding to their concern. In this work the impact of soft errors on the bus interconnect logic was investigated and a product was developed to ameliorate the effects of such errors on ARM’s customers’ products. Methods to measure the SER of ARM IP were investigated by focusing on logical masking, which is a component in the calculation of the SER. The effect that the topology of a combinatorial logic circuit has on its logical masking rate was considered by performing gate-level statistical fault injection on different implementations of adder circuits. Significant variation in logical masking was found ranging from a factor of 3.1 at a synthesis frequency of 100 MHz to a factor of 2.1 at 900 MHz. This difference is explained in an original way by correlating logical masking with the circuit’s path length and fan-out. These properties could be used to create a static method of measuring the logical masking rather than the current time-consuming method of dynamic simulation. Additionally, nearly 30% of faults injected cause more than one error, which means that the combinational SER will be underestimated if research does not take gate fan-out into consideration. Using this methodology a circuit designer can now base his choice or development of a circuit on its reliability as well as its performance, power, and area. Studying the variation in the factors that affect the SER is important to ensure accuracy in addressing customer requirements. Although it is important to consider the rate of soft error occurrence, in this work the impact of errors is demonstrated to be critical. Using protocol-level fault injection it is shown that faults on the ARM AXI bus interconnect can have a serious effect on the reliability of the entire SoC such as deadlock, memory corruption, or undefined behaviour. Using a fault-path traversal algorithm, it is demonstrated that traditional error detection codes are not sufficient at preventing these failures when faults occur on certain AXI bus signals. This led to the development of novel fault tolerant methods that provide protection for these identified signals. Based on these developments, a product was proposed for an add-on to the AXI bus interconnect that can detect, correct, and report logic soft errors without changing the AMBA standard or the customer’s connecting IP

Mixed-monolayer glyconanoparticles for the detection of cholera toxin by surface enhanced raman spectroscopy

The same interactions that a pathogen uses for establishment in a host can be exploited in its detection. The carbohydrates comprising the intestinal cell surface GM1-ganglioside, are targeted by vibrio cholerae via the lectin, cholera toxin, to initiate infection. We report on the preparation of mixed-monolayer, carbohydrate-coated silver nanoparticles (glyconanoparticles) for the sensitive (56 ng/mL), low volume detection of cholera toxin B-subunit (CTB) in synthetic freshwater samples and in 5 minutes by surface enhanced Raman spectroscopy (SERS). The detection limit falls within the recommended detection range and matches WHO approved test limits. PEGylated galactose and sialic acid are added in a specific ratio to coat the particles in GM1-ganglioside mimics for interaction with CTB and display a synergic effect greater than either glycan alone. This demonstrates the first use of a mixed-monolayer glyconanoparticle which mimics the GM1 ligand, allowing selective interaction with CTB

Doing more harm than good? Community based natural resource management and the neglect of local institutions in policy development

Approaches to natural resource management emphasise the importance of involving local people and institutions in order to build capacity, limit costs, and achieve environmental sustainability. Governments worldwide, often encouraged by international donors, have formulated devolution policies and legal instruments that provide an enabling environment for devolved natural resource management. However, implementation of these policies reveals serious challenges. This article explores the effects of limited involvement of local people and institutions in policy development and implementation. An in-depth study of the Forest Policy of Malawi and Village Forest Areas in the Lilongwe district provides an example of externally driven policy development which seeks to promote local management of natural resources. The article argues that policy which has weak ownership by national government and does not adequately consider the complexity of local institutions, together with the effects of previous initiatives on them, can create a cumulative legacy through which destructive resource use practices and social conflict may be reinforced. In short, poorly developed and implemented community based natural resource management policies can do considerably more harm than good. Approaches are needed that enable the policy development process to embed an in-depth understanding of local institutions whilst incorporating flexibility to account for their location-specific nature. This demands further research on policy design to enable rigorous identification of positive and negative institutions and ex-ante exploration of the likely effects of different policy interventions

Jim Allen : radical drama beyond 'days of hope'

Due to a desire to establish television as a serious medium, television drama has often been seen as a forum for writers, with names such as David Mercer, Dennis Potter and Trevor Griffiths identified by critics as the driving force, or auteur, behind the works that bear their names rather than, as in much writing about film, the director. However, while this has been so, there are also many examples of writers whose contribution to television writing has been much less celebrated, often due to their close collaboration with a high-profile director who in many critics’ view remains the most influential contributor to the final piece of work. One practitioner who arguably has failed to get the critical credit he is due is Jim Allen, a writer still perhaps best known for his work with one such high-profile director, Ken Loach

Complexity in decision making: Determining university library opening hours.

Making decisions on academic library opening hours is complex with many pressures on managers. This research surveys senior academic library managers from the UK, using a questionnaire to reveal views on library opening hours, the decision making process, and the pressures which influenced their decisions. A variety of factors were found, in particular satisfying undergraduate demands. The research also revealed the sources of information important in making decisions on opening hours and the influence of ‘political’ issues in the decision making process. Some institutions remove complexity by utilising 24/7 opening, though this is not an option for many

Stellar clustering and the kinematics of stars around Collinder 121 using Gaia DR3

We study the region around Collinder 121 (Cr 121) using newly available 6-dimensional data from the Gaia DR3 catalogue. Situated in the third quadrant, near the galactic plane, Collinder 121 lies in the region of Canis Major centred around l = 236 degrees, b = -10 degrees. Previous studies have suggested that the stellar associations in this region comprise an OB association (CMa OB2) lying at about 740 pc with a more distant open cluster (Cr 121) at approximately 1170 pc. Despite these studies, the precise nature of Collinder 121 remains uncertain. This study investigates the region bounded by the box l = 225 to 245 degrees, b = 0.00 to -20.00 degrees to a depth of 700 pc from 500 to 1200 pc which fully encompasses the region discussed in the literature. Using Gaia DR3 data, we do not find associations at the distances given in the literature. Instead, using the HDBSCAN machine learning algorithm, we find a major association of OB stars centred around 803 pc. Within this association we find four smaller subgroups that may be indicative of a larger association and which are located at a mean distance of 827 pc. Proper motion studies find coherence between these four subgroups and show a distinctive east to west increase in the size of the velocity vectors which supports contemporary studies that show similar trends in OB populations in Cygnus and within the Carina spiral Arm. Therefore, we hypothesize that Cr 121 and CMa OB2 are the same cluster, consistent with the 1977 study by Hoogerwerf

Luminal Ca2+–regulated Mg2+ Inhibition of Skeletal RyRs Reconstituted as Isolated Channels or Coupled Clusters

In resting muscle, cytoplasmic Mg2+ is a potent inhibitor of Ca2+ release from the sarcoplasmic reticulum (SR). It is thought to inhibit calcium release channels (RyRs) by binding both to low affinity, low specificity sites (I-sites) and to high affinity Ca2+ sites (A-sites) thus preventing Ca2+ activation. We investigate the effects of luminal and cytoplasmic Ca2+ on Mg2+ inhibition at the A-sites of skeletal RyRs (RyR1) in lipid bilayers, in the presence of ATP or modified by ryanodine or DIDS. Mg2+ inhibits RyRs at the A-site in the absence of Ca2+, indicating that Mg2+ is an antagonist and does not simply prevent Ca2+ activation. Cytoplasmic Ca2+ and Cs+ decreased Mg2+ affinity by a competitive mechanism. We describe a novel mechanism for luminal Ca2+ regulation of Ca2+ release whereby increasing luminal [Ca2+] decreases the A-site affinity for cytoplasmic Mg2+ by a noncompetitive, allosteric mechanism that is independent of Ca2+ flow. Ryanodine increases the Ca2+ sensitivity of the A-sites by 10-fold, which is insufficient to explain the level of activation seen in ryanodine-modified RyRs at nM Ca2+, indicating that ryanodine activates independently of Ca2+. We describe a model for ion binding at the A-sites that predicts that modulation of Mg2+ inhibition by luminal Ca2+ is a significant regulator of Ca2+ release from the SR. We detected coupled gating of RyRs due to luminal Ca2+ permeating one channel and activating neighboring channels. This indicated that the RyRs existed in stable close-packed rafts within the bilayer. We found that luminal Ca2+ and cytoplasmic Mg2+ did not compete at the A-sites of single open RyRs but did compete during multiple channel openings in rafts. Also, luminal Ca2+ was a stronger activator of multiple openings than single openings. Thus it appears that RyRs are effectively “immune” to Ca2+ emanating from their own pore but sensitive to Ca2+ from neighboring channels