72 research outputs found

    The role of ocelli in cockroach optomotor performance

    Get PDF
    Insect ocelli are relatively simple eyes that have been assigned various functions not related to pictorial vision. In some species they function as sensors of ambient light intensity, from which information is relayed to various parts of the nervous system, e.g., for the control of circadian rhythms. In this work we have investigated the possibility that the ocellar light stimulation changes the properties of the optomotor performance of the cockroach Periplaneta americana. We used a virtual reality environment where a panoramic moving image is presented to the cockroach while its movements are recorded with a trackball. Previously we have shown that the optomotor reaction of the cockroach persists down to the intensity of moonless night sky, equivalent to less than 0.1 photons/s being absorbed by each compound eye photoreceptor. By occluding the compound eyes, the ocelli, or both, we show that the ocellar stimulation can change the intensity dependence of the optomotor reaction, indicating involvement of the ocellar visual system in the information processing of movement. We also measured the cuticular transmission, which, although relatively large, is unlikely to contribute profoundly to ocellar function, but may be significant in determining the mean activity level of completely blinded cockroaches

    A modular systematic review of antenatal interventions targeting modifiable environmental exposures in improving low birth weight

    Get PDF
    BACKGROUND: Low birth weight (LBW) increases the risk of short- and long-term morbidity and mortality from early life to adulthood. Despite research effort to improve birth outcomes the progress has been slow. OBJECTIVE: This systematic search and review of English language scientific literature on clinical trials aimed to compare the efficacy antenatal interventions to reduce environmental exposures including a reduction of toxins exposure, and improving sanitation, hygiene, and health-seeking behaviors, which target pregnant women to improve birth outcomes. METHODS: We performed eight systematic searches in MEDLINE (OvidSP), Embase (OvidSP), Cochrane Database of Systematic Reviews (Wiley Cochrane Library), Cochrane Central Register of Controlled Trials (Wiley Cochrane Library), CINAHL Complete (EbscoHOST) between 17 March 2020 and 26 May 2020. RESULTS: Four documents identified describe interventions to reduce indoor air pollution: two randomised controlled trials (RCTs), one systematic review and meta-analysis (SRMA) on preventative antihelminth treatment and one RCT on antenatal counselling against unnecessary caesarean section. Based on the published literature, interventions to reduce indoor air pollution (LBW: RR: 0.90 [0.56, 1.44], PTB: OR: 2.37 [1.11, 5.07]) or preventative antihelminth treatment (LBW: RR: 1.00 [0.79, 1.27], PTB: RR: 0.88 [0.43, 1.78]) are not likely to reduce the risk of LBW or Preterm birth (PTB). Data is insufficient on antenatal counselling against caesarian-sections. For other interventions, there is lack of published research data from RCTs. CONCLUSIONS: We conclude that there is a paucity of evidence from RCT on interventions that modify environmental risk factors during pregnancy to potentially improve birth outcomes. Magic bullets approach might not work and that it would be important to study the effect of the broader interventions, particularly in LMIC settings. Global interdisciplinary action to reduce harmful environmental exposures, is likely to help to reach global targets for LBW reduction and sustainably improve long-term population health.Peer reviewe

    Entrepreneurs’ age, institutions, and social value creation goals: a multi-country study

    Get PDF
    This study explores the relationship between an entrepreneur's age and his/her social value creation goals. Building on the lifespan developmental psychology literature and institutional theory, we hypothesize a U-shaped relationship between entrepreneurs’ age and their choice to create social value through their ventures, such that younger and older entrepreneurs create more social value with their businesses while middle age entrepreneurs are relatively more economically and less socially oriented with their ventures. We further hypothesize that the quality of a country’s formal institutions in terms of economic, social, and political freedom steepen the U-shaped relationship between entrepreneurs’ age and their choice to pursue social value creation as supportive institutional environments allow entrepreneurs to follow their age-based preferences. We confirm our predictions using multilevel mixed-effects linear regressions on a sample of over 15,000 entrepreneurs (aged between 18 and 64 years) in 45 countries from Global Entrepreneurship Monitor data. The findings are robust to several alternative specifications. Based on our findings, we discuss implications for theory and practice, and we propose future research directions

    Comparative analysis of five protein-protein interaction corpora

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Growing interest in the application of natural language processing methods to biomedical text has led to an increasing number of corpora and methods targeting protein-protein interaction (PPI) extraction. However, there is no general consensus regarding PPI annotation and consequently resources are largely incompatible and methods are difficult to evaluate.</p> <p>Results</p> <p>We present the first comparative evaluation of the diverse PPI corpora, performing quantitative evaluation using two separate information extraction methods as well as detailed statistical and qualitative analyses of their properties. For the evaluation, we unify the corpus PPI annotations to a shared level of information, consisting of undirected, untyped binary interactions of non-static types with no identification of the words specifying the interaction, no negations, and no interaction certainty.</p> <p>We find that the F-score performance of a state-of-the-art PPI extraction method varies on average 19 percentage units and in some cases over 30 percentage units between the different evaluated corpora. The differences stemming from the choice of corpus can thus be substantially larger than differences between the performance of PPI extraction methods, which suggests definite limits on the ability to compare methods evaluated on different resources. We analyse a number of potential sources for these differences and identify factors explaining approximately half of the variance. We further suggest ways in which the difficulty of the PPI extraction tasks codified by different corpora can be determined to advance comparability. Our analysis also identifies points of agreement and disagreement in PPI corpus annotation that are rarely explicitly stated by the authors of the corpora.</p> <p>Conclusions</p> <p>Our comparative analysis uncovers key similarities and differences between the diverse PPI corpora, thus taking an important step towards standardization. In the course of this study we have created a major practical contribution in converting the corpora into a shared format. The conversion software is freely available at <url>http://mars.cs.utu.fi/PPICorpora</url>.</p

    Antenatal interventions to address harmful behaviors and psychosocial risk factors in the prevention of low birth weight

    Get PDF
    Background: Risk factors related to the harmful behaviors, psychosocial wellbeing, and socio-economic circumstances in the lives of pregnant women can lead to adverse birth outcomes, including low birth weight (LBW). Objective: This systematic search and review aims to provide a comparative evidence synthesis on the effect of eleven antenatal interventions targeted to address psychosocial risk factors on adverse birth outcomes. Methods: We searched MEDLINE, Embase, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials and CINAHL Complete between March 2020 and May 2020. We included randomized controlled trials (RCTs) and reviews of RCTs of eleven antenatal interventions for pregnant females reporting LBW, preterm birth (PTB), small-for-gestational-age or stillbirth as outcomes. For interventions where randomization was either not feasible or unethical, we accepted non-randomized controlled studies. Results: Seven records contributed data to the quantitative estimates of the effect sizes and 23 contributed to narrative analysis. Psychosocial interventions for reducing smoking in pregnancy likely reduced the risk of LBW, and professionally provided psychosocial support for at-risk women possibly reduced the risk of PTB. Financial incentives or nicotine replacement therapy as smoking cessation aids, or virtually delivered psychosocial support did not appear to reduce the risk of adverse birth outcomes. The available evidence on these interventions was primarily from high-income countries. For other reviewed interventions (psychosocial interventions to reduce alcohol use, group based psychosocial support programs, intimate partner violence prevention interventions, antidepressant medication, and cash transfers) there was little evidence in any direction regarding the efficacy or the data was conflicting. Conclusions: Professionally provided psychosocial support during pregnancy in general and specifically as a means to reduce smoking can potentially contribute to improved newborn health. The gaps in the investments for research and implementation of psychosocial interventions should be addressed to better meet the global targets in LBW reduction.Peer reviewe

    How market structure drives commodity prices

    Get PDF
    We introduce an agent-based model, in which agents set their prices to maximize profit. At steady state the market self-organizes into three groups: excess producers, consumers and balanced agents, with prices determined by their own resource level and a couple of macroscopic parameters that emerge naturally from the analysis, akin to mean-field parameters in statistical mechanics. When resources are scarce prices rise sharply below a turning point that marks the disappearance of excess producers. To compare the model with real empirical data, we study the relationship between commodity prices and stock-to-use ratios in a range of commodities such as agricultural products and metals. By introducing an elasticity parameter to mitigate noise and long-term changes in commodities data, we confirm the trend of rising prices, provide evidence for turning points, and indicate yield points for less essential commodities

    A fast and flexible panoramic virtual reality system for behavioural and electrophysiological experiments

    Get PDF
    Ideally, neuronal functions would be studied by performing experiments with unconstrained animals whilst they behave in their natural environment. Although this is not feasible currently for most animal models, one can mimic the natural environment in the laboratory by using a virtual reality (VR) environment. Here we present a novel VR system based upon a spherical projection of computer generated images using a modified commercial data projector with an add-on fish-eye lens. This system provides equidistant visual stimulation with extensive coverage of the visual field, high spatio-temporal resolution and flexible stimulus generation using a standard computer. It also includes a track-ball system for closed-loop behavioural experiments with walking animals. We present a detailed description of the system and characterize it thoroughly. Finally, we demonstrate the VR system’s performance whilst operating in closed-loop conditions by showing the movement trajectories of the cockroaches during exploratory behaviour in a VR forest

    BioInfer: a corpus for information extraction in the biomedical domain

    Get PDF
    BACKGROUND: Lately, there has been a great interest in the application of information extraction methods to the biomedical domain, in particular, to the extraction of relationships of genes, proteins, and RNA from scientific publications. The development and evaluation of such methods requires annotated domain corpora. RESULTS: We present BioInfer (Bio Information Extraction Resource), a new public resource providing an annotated corpus of biomedical English. We describe an annotation scheme capturing named entities and their relationships along with a dependency analysis of sentence syntax. We further present ontologies defining the types of entities and relationships annotated in the corpus. Currently, the corpus contains 1100 sentences from abstracts of biomedical research articles annotated for relationships, named entities, as well as syntactic dependencies. Supporting software is provided with the corpus. The corpus is unique in the domain in combining these annotation types for a single set of sentences, and in the level of detail of the relationship annotation. CONCLUSION: We introduce a corpus targeted at protein, gene, and RNA relationships which serves as a resource for the development of information extraction systems and their components such as parsers and domain analyzers. The corpus will be maintained and further developed with a current version being available at

    Measuring new product and service portfolio advantage

    Get PDF
    The current study introduces the concept of new product and service portfolio (NPSP) advantage by creating and validating a three-dimensional measurement method that reflects novelty, meaningfulness and superiority – the three characteristics of NPSP advantage. Based on industry-wide homogeneous generalizable quantitative data from 108 manufacturing companies, the results indicate that these three characteristics of NPSP – novelty, meaningfulness and superiority – are distinct characteristics that together constitute NPSP advantage. This paper contributes to the literature on new product development, as its findings suggest that when measuring the concept of NPSP advantage, the three-dimensional construct that includes the three aforementioned characteristics has a better fit to the data than the unidimensional structure. Because it considers both new products and services, the current study offers an integrated approach to measure the desired innovation process outcome (NPSP advantage). In this way, this paper bridges the research on new product development with that on new service development.fi=vertaisarvioitu|en=peerReviewed

    Towards a New Paradigm for Intuitive Theatrical Lighting Control

    Get PDF
    A simplified model of a lighting process applied in theatrical productions is one that involves two key players. The first is that of the lighting designer, to produce a set of intentions and plans for the scenes that define the show. The second, the lighting technician, has the job of translating these designs into practice using control equipment, luminaires, and other technical instruments. The lighting design often becomes a ‘working document’ subject to change and adaptation as the physical reality of the design becomes apparent, and the input of other stakeholders is considered. This process can be a valuable creative tool, and also a difficult technical hurdle to overcome, depending on a varied number of factors. A common frustration with this process is that either the complexity of the task, or difficulty in communication can make it difficult for the final creative vision to be effectively realised. Strains may also arise in the case of small, often touring, theatre companies where the lighting designer and technician may be the same person, and frequently one of the performers as well. Considering the design aspect, there can be challenges in ensuring efficacy of lighting plans between venues in touring productions, with 2D lighting sketches or even 3D computer simulations confined to the paper or screen. From a technical perspective, the role of the lighting technician in theatres and performance situations has included the operation of lighting control equipment during shows. The equipment has evolved over time but has, until recently, been grounded upon the basis of faders and the mixing desk. It is argued that this paradigm has failed to keep pace with the change in other interactive technologies. The on-going research described in this paper explores existing and upcoming technologies in the field, whilst also seeking to understand the roles and communication workflows of those involved in theatrical lighting to find the best areas to seek improvement, adopting principles of user-centred design. The intention of this research is to develop a new paradigm, and manifestation of it, using a control method for lighting or projection that allows a more intuitive form of operation in theatre productions, which will be scalable and flexible
    corecore