Comparison of diagnostic ability between a fast strategy, tendency-oriented perimetry, and the standard bracketing strategy

Purpose: To compare the diagnostic abilities of the standard bracketing strategy (BR) and a fast strategy, the tendency-oriented perimetry (TOP). Methods: Seventy-seven controls and 91 eyes from patients with glaucoma were analyzed with the strategies TOP and BR. Sensitivity (Se), specificity (Sp), the area under the receiver operating characteristic (ROC) curve (AC) and the optimum cutoff value (CO) were calculated for the visual field indices mean defect (MD), the square root of the loss variance (sLV) and the number of pathological points (NPP). Results: In the glaucoma group, the mean MD value using TOP and BR was 7.5 and 8.3 dB, respectively. The mean sLV value using TOP and BR was 5.0 and 5.3 dB, respectively. Indices provided by TOP had higher ROC values than the ones provided by BR. Using TOP, the index with the best diagnostic ability was sLV (Sp = 94.8, Se = 90.1, AC = 0.966, CO = 2.5 dB), followed by NPP and MD. Using BR, the best results were obtained for MD (Sp = 92.2, Se = 81.3, AC = 0.900, CO = 2.5 dB) followed by sLV and NPP. Conclusions: A fast strategy, TOP, had superior diagnostic ability than the standard BR. Although TOP provided lower LV values than BR, the diagnostic ability of this index was higher than that of the conventional strategy. Copyright © 2005 S. Karger AG.

Primary assembly of soil communities: disentangling the effect of dispersal and local environment

It has long been recognised that dispersal abilities and environmental factors are important in shaping invertebrate communities, but their relative importance for primary soil community assembly has not yet been disentangled. By studying soil communities along chronosequences on four recently emerged nunataks (ice-free land in glacial areas) in Iceland, we replicated environmental conditions spatially at various geographical distances. This allowed us to determine the underlying factors of primary community assembly with the help of metacommunity theories that predict different levels of dispersal constraints and effects of the local environment. Comparing community assembly of the nunataks with that of non-isolated deglaciated areas indicated that isolation of a few kilometres did not affect the colonisation of the soil invertebrates. When accounting for effects of geographical distances, soil age and plant richness explained a significant part of the variance observed in the distribution of the oribatid mites and collembola communities, respectively. Furthermore, null model analyses revealed less co-occurrence than expected by chance and also convergence in the body size ratio of co-occurring oribatids, which is consistent with species sorting. Geographical distances influenced species composition, indicating that the community is also assembled by dispersal, e.g. mass effect. When all the results are linked together, they demonstrate that local environmental factors are important in structuring the soil community assembly, but are accompanied with effects of dispersal that may "override" the visible effect of the local environment.

Design of a wideband conformal array antenna system with beamforming and null steering, for application in a DVB-T based passive radar

The use of radars in detecting low flying, small targets is being explored for several decades now. However radar with counter-stealth abilities namely the passive, multistatic, low frequency radars are in the focus recently. Passive radar that uses Digital Video Broadcast Terrestrial (DVB-T) signals as illuminator of opportunity is a major contender in this area. A DVB-T based passive radar requires the development of an antenna array that performs satisfactorily over the entire DVB-T band. At Fraunhofer FHR, there is currently a need for an array antenna to be designed for operation over the 450-900 MHz range with wideband beamforming and null steering capabilities. This would add to the ability of the passive radar in detecting covert targets and would improve the performance of the system. The array should require no mechanical adjustments to inter-element spacing to correspond to the DVB-T carrier frequency used for any particular measurement. Such an array would have an increased flexibility of operation in different environment or locations.

The design of such an array antenna and the applied techniques for wideband beamforming and null steering are presented in the thesis. The interaction between the inter-element spacing, the grating lobes and the mutual couplings had to be carefully studied and an optimal solution was to be reached at that meets all the specifications of the antenna array for wideband applications. Directional beams, nulls along interference directions, low sidelobe levels, polarization aspects and operation along a wide bandwidth of 450-900 MHz were some of the key considerations.

The Analogical Peacock Hypothesis: The Sexual Selection of Mind-Reading and Relational Cognition in Human Communication

This integrative review presents a novel hypothesis as a basis for integrating two evolutionary viewpoints on the origins of human cognition and communication, the sexual selection of human mental capacities, and the social brain hypothesis. This new account suggests that mind-reading social skills increased reproductive success and consequently became targets for sexual selection. The hypothesis proposes that human communication has three purposes: displaying mind-reading abilities, aligning and maintaining representational parity between individuals to enable displays, and the exchange of propositional information. Intelligence, creativity, language, and humor are mental fitness indicators that signal an individual’s quality to potential mates, rivals, and allies. Five features central to the proposed display mechanism unify these indicators, the relational combination of concepts, large conceptual knowledge networks, processing speed, contextualization, and receiver knowledge. Sufficient between-mind alignment of conceptual networks allows displays based upon within-mind conceptual mappings. Creative displays communicate previously unnoticed relational connections and novel conceptual combinations demonstrating an ability to read a receiver’s mind. Displays are costly signals of mate quality with costs incurred in the developmental production of the neural apparatus required to engage in complex displays and opportunity costs incurred through time spent acquiring cultural knowledge. Displays that are fast, novel, spontaneous, contextual, topical, and relevant are hard-to-fake for lower quality individuals. Successful displays result in elevated social status and increased mating options. The review addresses literatures on costly signaling, sexual selection, mental fitness indicators, and the social brain hypothesis; drawing implications for nonverbal and verbal communication.

Efficacy of Biocides Used in the Modern Food Industry To Control Salmonella enterica, and Links between Biocide Tolerance and Resistance to Clinically Relevant Antimicrobial Compounds

Biocides play an essential role in limiting the spread of infectious disease. The food industry is dependent on these agents, and their increasing use is a matter for concern. Specifically, the emergence of bacteria demonstrating increased tolerance to biocides, coupled with the potential for the development of a phenotype of cross-resistance to clinically important antimicrobial compounds, needs to be assessed. In this study, we investigated the tolerance of a collection of susceptible and multidrug-resistant (MDR) Salmonella enterica strains to a panel of seven commercially available food-grade biocide formulations. We explored their abilities to adapt to these formulations and their active biocidal agents, i.e., triclosan, chlorhexidine, hydrogen peroxide, and benzalkonium chloride, after sequential rounds of in vitro selection. Finally, cross-tolerance of different categories of biocidal formulations, their active agents, and the potential for coselection of resistance to clinically important antibiotics were investigated. Six of seven food-grade biocide formulations were bactericidal at their recommended working concentrations. All showed a reduced activity against both surface-dried and biofilm cultures. A stable phenotype of tolerance to biocide formulations could not be selected. Upon exposure of Salmonella strains to an active biocidal compound, a high-level of tolerance was selected for a number of Salmonella serotypes. No cross-tolerance to the different biocidal agents or food-grade biocide formulations was observed. Most tolerant isolates displayed changes in their patterns of susceptibility to antimicrobial compounds. Food industry biocides are effective against planktonic Salmonella. When exposed to sublethal concentrations of individual active biocidal agents, tolerant isolates may emerge. This emergence was associated with changes in antimicrobial susceptibilities.

Fraternities and Labor Market Outcomes

We model how student choices to rush a fraternity, and fraternity admission choices, interact with signals firms receive about student productivities to determine labor-market outcomes. The fraternity and students value wages and fraternity socializing values. We provide sufficient conditions under which, in equilibrium, most members have intermediate abilities: weak students apply, but are rejected unless they have high socializing values, while most able students do not apply to avoid taint from association with weaker members.

University Competition, Grading Standards, and Grade Inflation

We develop a model of strategic grade determination by universities distinguished by their distributions of student academic abilities. Universities choose grading standards to maximize the total wages of graduates, taking into account how the grading standards affect firms' productivity assessment and job placement. We identify conditions under which better universities set lower grading standards, exploiting the fact that firms cannot distinguish between good and badA''s. In contrast, a social planner sets stricter standards at better universities. We show how increases in skilled jobs drive grade inflation, and determine when grading standards fall faster at better schools. (JEL I21)

Using a Systematic Approach To Develop a Chemistry Course Introducing Students to Instrumental Analysis

A systematic approach to develop the teaching of instrumental analytical chemistry is discussed, as well as a conceptual framework for organizing and executing lectures and a laboratory course. Three main components are used in this course: theoretical knowledge developed in the classroom, simulations via a virtual laboratory, and practical training via experimentation. Problem-based learning and cooperative-learning methods are applied in both the classroom and laboratory aspects of the course. In addition, some reflections and best practices are presented on how to encourage students to learn actively. Overall, a student-centered environment is proposed that aims to cultivate students' practical abilities and individual talents.

A leadership framework to support the use of e-learning resources

Aim
This inquiry aims to apply the NHS leadership framework to nurse education for the implementation of e-learning.
Background
Recognition needs to be given to the emerging postgraduate nursing students new status of consumer and the challenge now for nurse education is how to remain relevant and competitive in this consumer led market. The move towards an e-learning paradigm has been suggested as a competitive and contemporary way forward for the student consumer. The successful introduction of e-learning in nurse education will require leadership and a strong organisational management system.
Discussion
Each element of the NHS leadership framework is described and interpreted for application in a higher education setting for the implementation of e-learning.
Conclusions
Change in the delivery of post graduate nurse education is necessary to ensure it remains current and reflective of consumer need in a competitive marketplace. By applying a leadership framework that acknowledges the skills and abilities of staff and encourages the formation of collaborative partnerships from within the wider university community, educators can begin to develop skills and confidence in teaching using e-learning resources.

Next generation femtocells: An enabler for high efficiency multimedia transmission

The first generation of femtocells is evolving to the next generation with many more capabilities in terms of better utilisation of radio resources and support of high data rates. It is thus logical to conjecture that with these abilities and their inherent suitability for home environment, they stand out as an ideal enabler for delivery of high efficiency multimedia services. This paper presents a comprehensive vision towards this objective and extends the concept of femtocells from indoor to outdoor environments, and strongly couples femtocells to emergency and safety services. It also presents and identifies relevant issues and challenges that have to be overcome in realization of this vision.

Flexibility of Continental Navigation and Migration in European Mallards

The ontogeny of continent-wide navigation mechanisms of the individual organism, despite being crucial for the understanding of animal movement and migration, is still poorly understood. Several previous studies, mainly conducted on passerines, indicate that inexperienced, juvenile birds may not generally correct for displacement during fall migration. Waterbirds such as the mallard (Anas platyrhynchos, Linnaeus 1758) are more flexible in their migration behavior than most migratory songbirds, but previous experiments with waterbirds have not yet allowed clear conclusions about their navigation abilities. Here we tested whether immature mallard ducks correct for latitudinal displacement during fall migration within Europe. During two consecutive fall migration periods, we caught immature females on a stopover site in southeast Sweden, and translocated a group of them ca. 1,000 km to southern Germany. We followed the movements of the ducks via satellite GPS-tracking and observed their migration decisions during the fall and consecutive spring migration. The control animals released in Ottenby behaved as expected from banding recoveries: they continued migration during the winter and in spring returned to the population's breeding grounds in the Baltics and Northwest Russia. Contrary to the control animals, the translocated mallards did not continue migration and stayed at Lake Constance. In spring, three types of movement tactics could be observed: 61.5% of the ducks (16 of 26) stayed around Lake Constance, 27% (7 of 26) migrated in a northerly direction towards Sweden and 11.5% of the individuals (3 of 26) headed east for ca. 1,000 km and then north. We suggest that young female mallards flexibly adjust their migration tactics and develop a navigational map that allows them to return to their natal breeding area.

Do Nonagenarians siblings provide mutual support? Insights from the EU GeHA project

Introduction.– Sibling relationships have been described as intimate,
congenial, loyal, apathetic or hostile but little is known about
sibling relationships in very old age.Weasked nonagenarian brothers
and sisters from the EU-funded Genetics of Healthy Ageing
(GeHA) project whether they had felt supported by having a living
sibling to have better coping abilities.
Methods and results.– Nonagenarian siblings were a convenience
sample from four countries from the GeHA study–Italy, Poland,
N Ireland, Finland. All were consented willing participants. Most
male/female dyads demonstrated healthy respect for each other’s
opinion and their sibling relationship fits the “loyal” type, though
with a clear sense of independence.Noneof the eight female/female
nor the one male/male dyad seemed to fit the “intimate” description;
two might be described as “apathetic”, while the other two
seemed to show aspects of family “loyalty”, alongside other traits
perhaps best described as “congenial”. There were apparent different
cultural influences across Europe with siblings in Italy and
Poland more likely to report supportive siblinghood, compared to
sibling pairs/trios in Finland or N Ireland where self-resilience and
independence seemed more common. Polish and Italian nonagenarians
often felt supported by their religious faith and church.
Conclusions.– In general, nonagenarian siblings most often demonstrated
loyal family relationships, which may have helped each
other’s coping and survival mechanisms. However, there was
widespread evidence of tolerance for individual decision-making.
Perhaps rather, these 90-year-olds survive because they are
resilient and independent and don’t need to depend on each other!

Dorsal and ventral stream mediated visual processing in genetic subtypes of Prader-Willi syndrome

Previous work has suggested that there are specific deficits in dorsal stream processing in a variety of developmental disorders. Prader-Willi syndrome (PWS) is associated with two main genetic subtypes, deletion and disomy. Relative strengths in visual processing are shown in PWS, although these strengths may be specific to the deletion subtype. We investigated visual processing in PWS using an adapted Simon task which contrasted location (dorsal stream) and shape identity (ventral stream) tasks. Compared to a group of typically developing children, children with PWS deletion showed a greater degree of impairment in the dorsal stream task than in the ventral stream task, a pattern similar to that shown in a group of boys with Fragile-X syndrome. When matched on a measure of non-verbal ability, children with PWS disomy showed the opposite pattern with better performance in the location compared to the shape task, although these task performance asymmetries may have been linked to executive control processes. It is proposed that children with PWS deletion show a relative strength in visual processing in the ventral stream along with a specific deficit in dorsal stream processing. In contrast, children with PWS disomy show neither effect. (C) 2009 Published by Elsevier Ltd.

Tutoría entre iguales recíproca y virtual para la mejora de habilidades lingüísticas en español e inglés

This paper reports data from an on-line peer tutoring project, the objective being the learning and improvement of the Spanish and English language. Pupils aged between 9 and 12 years old from Scotland and Catalonia were paired for the purpose of each pupil acting as a tutor of their own language within his or her pair. The aim was to improve the knowledge and use of their own language (by correcting their tutee) as well as the modern language (through the help of their tutor) acting as tutors and also as a tutees. The research combines a quasi-experimental design, using control groups, and in depth analysis of the process throughout the exchanges (texts and corrections) and interviews with the subjects. The results show that the degree of help offered by the tutors appears to be a very relevant factor when assessing the improvement detected in the linguistic abilities. © 2010 Fundación Infancia y Aprendizaje.

Temporal and statistical information in causal structure learning

Three experiments examined children’s and adults’ abilities to use statistical and temporal information to distinguish between common cause and causal chain structures. In Experiment 1, participants were provided with conditional probability information and/or temporal information and asked to infer the causal structure of a three-variable mechanical system that operated probabilistically. Participants of all ages preferentially relied on the temporal pattern of events in their inferences, even if this conflicted with statistical information. In Experiments 2 and 3, participants observed a series of interventions on the system, which in these experiments operated deterministically. In Experiment 2, participants found it easier to use temporal pattern information than statistical information provided as a result of interventions. In Experiment 3, in which no temporal pattern information was provided, children from 6-7 years, but not younger children, were able to use intervention information to make causal chain judgments, although they had difficulty when the structure was a common cause. The findings suggest that participants, and children in particular, may find it more difficult to use statistical information than temporal pattern information because of its demands on information processing resources. However, there may also be an inherent preference for temporal information.