Environmental context explains Lévy and Brownian movement patterns of marine predators

An optimal search theory, the so-called Levy-flight foraging hypothesis(1), predicts that predators should adopt search strategies known as Levy flights where prey is sparse and distributed unpredictably, but that Brownian movement is sufficiently efficient for locating abundant prey(2-4). Empirical studies have generated controversy because the accuracy of statistical methods that have been used to identify Levy behaviour has recently been questioned(5,6). Consequently, whether foragers exhibit Levy flights in the wild remains unclear. Crucially, moreover, it has not been tested whether observed movement patterns across natural landscapes having different expected resource distributions conform to the theory's central predictions. Here we use maximum-likelihood methods to test for Levy patterns in relation to environmental gradients in the largest animal movement data set assembled for this purpose. Strong support was found for Levy search patterns across 14 species of open-ocean predatory fish (sharks, tuna, billfish and ocean sunfish), with some individuals switching between Levy and Brownian movement as they traversed different habitat types. We tested the spatial occurrence of these two principal patterns and found Levy behaviour to be associated with less productive waters (sparser prey) and Brownian movements to be associated with productive shelf or convergence-front habitats (abundant prey). These results are consistent with the Levy-flight foraging hypothesis(1,7), supporting the contention(8,9) that organism search strategies naturally evolved in such a way that they exploit optimal Levy patterns.

Comparison of a centralised and distributed approach for a generic scheduling system

PEGS (Production and Environmental Generic Scheduler) is a generic production scheduler that produces good schedules over a wide range of problems. It is centralised, using search strategies with the Shifting Bottleneck algorithm. We have also developed an alternative distributed approach using software agents. In some cases this reduces run times by a factor of 10 or more. In most cases, the agent-based program also produces good solutions for published benchmark data, and the short run times make our program useful for a large range of problems. Test results show that the agents can produce schedules comparable to the best found so far for some benchmark datasets and actually better schedules than PEGS on our own random datasets. The flexibility that agents can provide for today's dynamic scheduling is also appealing. We suggest that in this sort of generic or commercial system, the agent-based approach is a good alternative.

Strasheela: Design and usage of a music composition environment based on the Oz programming model

Strasheela provides a means for the composer to create a symbolic score by formally describing it in a rule-based way. The environment defines a rich music representation for complex polyphonic scores. Strasheela enables the user to define expressive compositional rules and then to apply them to the score. Compositional rules can restrict many aspects of the music - including the rhythmic structure, the melodic structure and the harmonic structure - by constraining the parameters (e.g. duration or pitch) of musical events according to some numerical or logical relation. Strasheela combines this expressivity with efficient search strategies.

Environmental context explains Levy and Brownian movement patterns of marine predators

An optimal search theory, the so-called Levy-flight foraging hypothesis(1), predicts that predators should adopt search strategies known as Levy flights where prey is sparse and distributed unpredictably, but that Brownian movement is sufficiently efficient for locating abundant prey(2-4). Empirical studies have generated controversy because the accuracy of statistical methods that have been used to identify Levy behaviour has recently been questioned(5,6). Consequently, whether foragers exhibit Levy flights in the wild remains unclear. Crucially, moreover, it has not been tested whether observed movement patterns across natural landscapes having different expected resource distributions conform to the theory's central predictions. Here we use maximum-likelihood methods to test for Levy patterns in relation to environmental gradients in the largest animal movement data set assembled for this purpose. Strong support was found for Levy search patterns across 14 species of open-ocean predatory fish (sharks, tuna, billfish and ocean sunfish), with some individuals switching between Levy and Brownian movement as they traversed different habitat types. We tested the spatial occurrence of these two principal patterns and found Levy behaviour to be associated with less productive waters (sparser prey) and Brownian movements to be associated with productive shelf or convergence-front habitats (abundant prey). These results are consistent with the Levy-flight foraging hypothesis(1,7), supporting the contention(8,9) that organism search strategies naturally evolved in such a way that they exploit optimal Levy patterns.

Systematic review of reviews of risk factors for intracranial aneurysms

Systematic reviews of systematic reviews identify good quality reviews of earlier studies of medical conditions. This article describes a systematic review of systematic reviews performed to investigate factors that might influence the risk of rupture of an intracranial aneurysm. It exemplifies the technique of this type of research and reports the finding of a specific study. The annual incidence of subarachnoid haemorrhage resulting from the rupture of intracranial aneurysms is estimated to be nine per 100,000. A large proportion of people who have this bleed, will die or remain dependent on the care of others for some time. Reliable knowledge about the risks of subarachnoid haemorrhage in different populations will help in planning, screening and prevention strategies and in predicting the prognosis of individual patients. If the necessary data were available in the identified reviews, an estimate for the numerical relationship between a particular characteristic and the risk of subarachnoid haemorrhage was included in this report. The identification of eligible systematic reviews relied mainly on the two major bibliographic databases of the biomedical literature: PubMed and EMBASE. These were searched in 2006, using specially designed search strategies. Approximately 2,000 records were retrieved and each of these was checked carefully against the eligibility criteria for this systematic review. These criteria required that the report be a systematic review of studies assessing the risk of subarachnoid haemorrhage in patients known to have an unruptured intracranial aneurysm or of studies that had investigated the characteristics of people who experienced a subarachnoid haemorrhage without previously being known to have an unruptured aneurysm. Reports which included more than one systematic review were eligible and each of these reviews was potentially eligible. The quality of each systematic review was assessed. In this review, 16 separate reports were identified, including a total of 46 eligible systematic reviews. These brought together research studies for 24 different risk factors. This has shown that the following factors appear to be associated with a higher risk of subarachnoid haemorrhage: being a woman, older age, posterior circulation aneurysms, larger aneurysms, previous symptoms,

Functional and Structural Diversification of the Anguimorpha Lizard Venom System

Venom has only been recently discovered to be a basal trait of the Anguimorpha lizards. Consequently, very little is known about the timings of toxin recruitment events, venom protein molecular evolution, or even the relative physical diversifications of the venom system itself. A multidisciplinary approach was used to examine the evolution across the full taxonomical range of this similar to 130 million-year-old clade. Analysis of cDNA libraries revealed complex venom transcriptomes. Most notably, three new cardioactive peptide toxin types were discovered (celestoxin, cholecystokinin, and YY peptides). The latter two represent additional examples of convergent use of genes in toxic arsenals, both having previously been documented as components of frog skin defensive chemical secretions. Two other novel venom gland-overexpressed modified versions of other protein frameworks were also recovered from the libraries (epididymal secretory protein and ribonuclease). Lectin, hyaluronidase, and veficolin toxin types were sequenced for the first time from lizard venoms and shown to be homologous to the snake venom forms. In contrast, phylogenetic analyses demonstrated that the lizard natriuretic peptide toxins were recruited independently of the form in snake venoms. The de novo evolution of helokinestatin peptide toxin encoding do-mains within the lizard venom natriuretic gene was revealed to be exclusive to the helodermatid/anguid subclade. New isoforms were sequenced for cysteine-rich secretory protein, kallikrein, and phospholipase A 2 toxins. Venom gland morphological analysis revealed extensive evolutionary tinkering. Anguid glands are characterized by thin capsules and mixed glands, serous at the bottom of the lobule and mucous toward the apex. Twice, independently this arrangement was segregated into specialized serous protein-secreting glands with thick capsules with the mucous lobules now distinct (Heloderma and the Lanthanotus/Varanus clade). The results obtained highlight the importance of utilizing evolution-based search strategies for biodiscovery and emphasize the largely untapped drug design and development potential of lizard venoms. Molecular & Cellular Proteomics 9:2369-2390, 2010.

Dietary fiber and the risk of precancerous lesions and cancer of the esophagus:a systematic review and meta-analysis

Dietary fiber has several anticarcinogenic effects and is thought to be protective against esophageal cancer. The aim of this systematic review was to quantify the association between dietary fiber and the risk of esophageal cancer by investigating histological subtypes of esophageal cancer and the stage at which fiber may influence the carcinogenic pathway. Systematic search strategies were used to identify relevant studies, and adjusted odds ratios (ORs) were combined using random-effects meta-analyses to assess the risk of cancer when comparing extreme categories of fiber intake. Ten relevant case-control studies were identified within the timeframe searched. Pooled estimates from eight studies of esophageal adenocarcinoma revealed a significant inverse association with the highest fiber intakes (OR 0.66; 95% confidence interval [CI] 0.44-0.98). Two studies also identified protective effects of dietary fiber against Barrett's esophagus. Similar, though nonsignificant, associations were observed when results from five studies of fiber intake and risk of squamous cell carcinoma were combined (OR 0.61; 95%CI 0.31-1.20). Dietary fiber is associated with protective effects against esophageal carcinogenesis, most notably esophageal adenocarcinoma. Potential methods of action include modification of gastroesophageal reflux and/or weight control.

Supported decision making: a review of the international literature

Supported decision making (SDM) refers to the process of supporting people, whose decision making ability may be impaired, to make decisions and so promote autonomy and prevent the need for substitute decision making. There have been developments in SDM but mainly in the areas of intellectual disabilities and end-of-life care rather than in mental health. The main aim of this review was to provide an overview of the available evidence relevant to SDM and so facilitate discussion of how this aspect of law, policy and practice may be further developed in mental health services. The method used for this review was a Rapid Evidence Assessment which involved: developing appropriate search strategies; searching relevant databases and grey literature; then assessing, including and reviewing relevant studies. Included studies were grouped into four main themes: studies reporting stakeholders’ views on SDM; studies identifying barriers to the implementation of SDM; studies highlighting ways to improve implementation; and studies on the impact of SDM. The available evidence on implementation and impact, identified by this review, is limited but there are important rights-based, effectiveness and pragmatic arguments for further developing and researching SDM for people with mental health problems.

Knowledge stocks, knowledge flows and innovation: Evidence from matched patents and innovation panel data

Successful innovation depends on knowledge – technological, strategic and market related. In this paper we explore the role and interaction of firms’ existing knowledge stocks and current knowledge flows in shaping innovation success. The paper contributes to our understanding of the determinants of firms’ innovation outputs and provides new information on the relationship between knowledge stocks, as measured by patents, and innovation output indicators. Our analysis uses innovation panel data relating to plants’ internal knowledge creation, external knowledge search and innovation outputs. Firm-level patent data is matched with this plant-level innovation panel data to provide a measure of firms’ knowledge stock. Two substantive conclusions follow. First, existing knowledge stocks have weak negative rather than positive impacts on firms’ innovation outputs, reflecting potential core-rigidities or negative path dependencies rather than the accumulation of competitive advantages. Second, knowledge flows derived from internal investment and external search dominate the effect of existing knowledge stocks on innovation performance. Both results emphasize the importance of firms’ knowledge search strategies. Our results also re-emphasize the potential issues which arise when using patents as a measure of innovation.

Where and how to find data on safety: what do systematic reviews of complementary therapies tell us?

Background: Successfully identifying relevant data for systematic reviews with a focus on safety may require retrieving information from a wider range of sources than for ‘effectiveness’ systematic reviews. Searching for safety data continues to prove a major challenge. Objectives: To examine search methods used in systematic reviews of safety and to investigate indexing. Methods: Systematic reviews focusing on safety of complementary therapies and related interventions were retrieved from comprehensive searches of major databases. Data was extracted on search strategies, sources used and indexing in major databases. Safety related search terms were compared against index terms available on major databases. Data extraction by one researcher using a pre-prepared template was checked for accuracy by a second researcher. Results: Screening of 2563 records resulted in 88 systematic reviews being identified. Information sources used varied with the type of intervention being addressed. Comparison of search terms with available index terms revealed additional potentially relevant terms that could be used in constructing search strategies. Seventy-nine reviews were indexed on PubMed, 84 on EMBASE, 21 on CINAHL, 15 on AMED, 6 on PsycINFO, 2 on BNI and HMIC. The mean number of generic safety-related indexing terms on PubMed records was 2.6. For EMBASE the mean number was 4.8 with at least 61 unique terms being employed. Most frequently used indexing terms and subheadings were adverse effects, side effects, drug interactions and herb-drug interactions. Use of terms specifically referring to safety varied across databases. Conclusions: Investigation of search methods revealed the range of information sources used, a list of which may prove a valuable resource for those planning to conduct systematic reviews of safety. The findings also indicated that there is potential to improve safety-related search strategies. Finally, an insight is provided into indexing of and most effective terms for finding safety studies on major databases.

Noyaux conceptuels et traduction médicale

Département de linguistique et de traduction

Information needs for a purchase of fairtrade coffee

This research investigates what information German Fairtrade coffee consumers search for during pre-purchase information seeking and to what extent information is retrieved. Furthermore, the sequence of the information search as well as the degree of cognitive involvement is highlighted. The role of labeling, the importance of additional ethical information and its quality in terms of concreteness as well as the importance of product price and organic origin are addressed. A set of information relevant to Fairtrade consumers was tested by means of the Information Display Matrix (IDM) method with 389 Fairtrade consumers. Results show that prior to purchase, information on product packages plays an important role and is retrieved rather extensively, but search strategies that reduce the information processing effort are applied as well. Furthermore, general information is preferred over specific information. Results of two regression analyses indicate that purchase decisions are related to search behavior variables rather than to socio-demographic variables and purchase motives. In order to match product information with consumers’ needs, marketers should offer information that is reduced to the central aspects of Fairtrade.

Common Craft

Common craft make short videos which explain in simple terms some common concepts and technologies used in learning and teaching. These are available through The Common Craft Store, which offers versions of videos that are: Downloadable files Presentation-quality Licensed for workplace use You can find the free, online versions of the videos on The Common Craft Show. Topics include phishing, RSS, wikis, Twitter, social networking, social bookmarking, web search strategies, social media, podcasting, sharing photos online and many more.

e-Research Methods Theme 3: Literature Review

This theme helps you to develop search strategies, select search terms and appraise references you retrieve in order to differentiate between helpful and irrelevant literature sources. In addition, it looks at ways in which you can manage your references and develop understanding and skills to become an effective and efficient user of Library resources and services.

MSc Audiology library induction, 2010

Library induction given to the postgraduate audiology students in October 2010. Session covers an introduction to the Hartley library including Library of Congress classification, finding items from reading lists, print journals, e-journals, search strategies including boolean operators and truncation and using online databases, in particular Web of Science.