1,314 research outputs found

    Adaptive correlations between seed size and germination time

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    We present a model for the coevolution of seed size and germination time within a season when both affect the ability of the seedlings to compete for space. We show that even in the absence of a morphological or physiological constraint between the two traits, a correlation between seed size and germination time is nevertheless likely to evolve. This raises the more general question to what extent a correlation between any two traits should be considered as an a priori constraint or as an evolved means (or instrument) to actually implement a beneficial combination of traits. We derive sufficient conditions for the existence of a positive or a negative correlation. We develop a toy model for seed and seedling survival and seedling growth and use this to illustrate in practice how to determine correlations between seed size and germination time.Peer reviewe

    Standoff UV-C imaging of alpha particle emitters

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    Alpha particles are proven to be very useful in many areas of medicine, technology and science. Yet, they represent the biggest risk to soft biological tissues compared to all nuclear decay products when ingested or inhaled, implying thus stringent radiation protection measures in the management and monitoring of samples that emit them. In this paper we present a standoff optical imaging approach that enables sensing of a radiological threat items at facilities where alpha-emitting material is manufactured, handled, used and stored, at safe distances without putting personnel at risk or contaminating equipment. The optical imaging of alpha-emitting samples is based on the radiation induced air luminescence (radioluminescence) in the UV-C (solar-blind) spectral region which enables detection of alpha particles even under bright light conditions. We show that by adding trace amounts of nitric oxide into the nitrogen atmosphere surrounding the sample, alpha sources with specific activities as low as 1.5 Bq/cm(2) can be remotely imaged. This work provides a proof-of-concept implementation of a novel imaging approach that not only enhances capabilities of a state to take actions which effectively mitigate consequences of an radiological emergency for the society, health, environment and economy, but also benefits nuclear industry in decommissioning efforts.Peer reviewe

    Hajalukujen tunnistaminen ja poistaminen RFID-porteilla

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    A modern UHF RFID system can reach a read range of over ten meters. Long read range and difficulties to create uniform interrogation zone lead to stray reads. Interrogation zone can be adjusted by controlling the transmit power of RFID reader, selecting antennas and RFID tags carefully for the purpose, and with different signal quality validation methods. It is common that industry processes prevent using optimal RFID tag size and location for best read reliability. In these situations reader transmit power is increased to gain better read reliability. This extends the interrogation zone over the designed and leads to stray reads. At UHF band the interrogation zone is not sharp edged. This is due to orientation differences between tags, tag to tag differences, multipathing and interference caused by multipathing. In this thesis, different methods to identify RFID-tags moving along specified routes in the far field on the specific interrogation zone and discard other read events as stray events, are studied. Algorithm to detect lay around tags is proposed.Modernin UHF RFID-jÀrjestelmÀn lukuetÀisyys on parhaimmillaan yli kymmenen metriÀ. Suuri lukuetÀisyys ja hankaluudet lukualueen tarkassa rajaamisessa johtavat hajalukuihin. Lukualuetta voidaan sÀÀtÀÀ RFID-lukijan lÀhetystehoa muuttamalla, antenni- ja RFID-tunnistevalinnoilla, sekÀ erilaisilla signaalin laatuun liittyvillÀ menetelmillÀ. Teollisuuden prosessit eivÀt aina mahdollista tunnisteen sijoittamista lukuvarmuuden kannalta parhaaseen paikkaan. TÀllaisissa tapauksissa joudutaan usein kasvattamaan RFID-lukijan lÀhetystehoa lukuvarmuuden parantamiseksi. TÀmÀ taas kasvattaa lukualuetta suunniteltua suuremmaksi, mikÀ johtaa hajalukuihin. UHF taajuuksilla lukualue ei ole tarkkareunainen, johtuen RFID-tunnisteiden asentoeroista, tunnisteiden yksilökohtaisista eroista sekÀ monikanavakuulumisesta ja siihen liittyvÀstÀ interferenssistÀ. TÀssÀ tutkimuksessa on etsitty ja kokeiltu menetelmiÀ, joilla voidaan tunnistaa mÀÀritellyllÀ lukualueella lukijan kaukokentÀssÀ haluttuja reittejÀ liikkuvat RFID-tunnisteet ja hylÀtÀ muut lukutapahtumat hajalukuina. Tutkimuksessa esitetÀÀn uusi algoritmi hajalukujen tunnistamiseksi

    Performance of Surgical Stress Index during Sevoflurane-Fentanyl and Isoflurane-Fentanyl Anesthesia

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    The performance of recently introduced Surgical Stress Index (SSI), based on heart rate and photoplethysmography, was estimated during sevoflurane-fentanyl and isoflurane-fentanyl anesthesia during surgical procedures. Forty ASA I–III patients were enrolled. Anesthesia was induced with fentanyl 2 Όg kg−1 and thiopentone 3–5 mg kg−1. Tracheal intubation was performed 5 minutes after fentanyl bolus. Patients were randomly allocated to receive sevoflurane (n = 20) or isoflurane (n = 20) in 30% oxygen/air. State entropy was kept at 40–60, target being 50. During surgery, fentanyl boluses 1.5 Όg kg−1 were given at 30–40-minute intervals. SSI increased significantly after intubation. During surgery, the decrease of SSI after fentanyl boluses was similar in sevoflurane and isoflurane groups but SSI values were higher in sevoflurane than in isoflurane group. Tracheal intubation, skin incision, and surgical stimuli increased SSI from baseline, indicating that nociceptive stimuli increase SSI. Fentanyl boluses during surgery decreased SSI, indicating that increasing analgesia decreases SSI

    Anomalous lifetime distributions and topological traps in ordering dynamics

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    We address the role of community structure of an interaction network in ordering dynamics, as well as associated forms of metastability. We consider the voter and AB model dynamics in a network model which mimics social interactions. The AB model includes an intermediate state between the two excluding options of the voter model. For the voter model we find dynamical metastable disordered states with a characteristic mean lifetime. However, for the AB dynamics we find a power law distribution of the lifetime of metastable states, so that the mean lifetime is not representative of the dynamics. These trapped metastable states, which can order at all time scales, originate in the mesoscopic network structure.Comment: 7 pages; 6 figure

    Humans, animals, things and animacy

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    Animacy influences the patterns of subject-verb agreement marking in many languages, including Persian and Inari Saami. In Persian, animate plural subjects trigger plural agreement on the verb, whereas inanimate subjects may or may not trigger agreement. The variation is governed by factors such as personification, agency and distributivity. In Inari Saami, verbs fully agree with human subjects and verbs partially agree with inanimate subjects. Verbs may or may not agree with subjects referring to animals. We argue that the intricate interaction between biological animacy and grammatical agreement in these two languages warrants careful consideration of the tripartite distinction between biological animacy in the world, our conceptualization of animacy and formal animacy features in the grammar

    Allocating Logging Rights in Peruvian Amazonia-Does It Matter to Be Local?

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    Conclusions/Significance: The allocation process left a considerable number of forest areas under the management of small and local actors, and if Peru is to reach its goal of zero deforestation rate by safeguarding 75 per cent of its forests by 2020, the small and the local actors need to be integrated to the forest regime as important constituents of its legitimacy

    Association between infant swimming and rhinovirus-induced wheezing.

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    AIM Infant swimming has been considered as a risk factor for wheezing, but the role that respiratory viruses play is unclear. We explored the effects of infant swimming on the risk of all wheezing illnesses and wheezing associated with rhinoviruses. METHODS We followed up a birth cohort of 1827 children until 17 months of age, collecting data on infant swimming, other risk factors and physician-diagnosed bronchiolitis or recurrent wheezing. Viral diagnostics were performed in a subset of children with all respiratory tract infections. RESULTS Data on infant swimming were obtained for 1038 children, with viral follow-up for 635 children. At least one wheezing illness was documented in 45/469 (9.6%) swimming children versus 39/569 (6.9%) nonswimming children (p = 0.11), and rhinoviruses were associated with wheezing in 11/296 (3.7%) swimming children versus 4/339 (1.2%) nonswimming children (p = 0.04). In adjusted logistic regression analyses, swimming had an odds ratio of 1.71 (p = 0.05) for bronchiolitis and 3.57 (p = 0.06) for rhinovirus-associated wheezing. An association between infant swimming and rhinovirus-associated wheezing was detected for children with atopic eczema (p = 0.006). CONCLUSION There may be a link between infant swimming and rhinovirus-induced wheezing illnesses in atopic infants.</p

    Feasibility of a Responsibility-Based Leadership Training Program for Novice Physical Activity Instructors

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    Most coaches and instructors would like to teach more than just sport skills to their athletes and children. However, to promote athletes' or children's holistic development and teach them to take responsibility and lead, requires the coaches and instructors to first master the skills themselves. Therefore, feasible, high quality leadership training programs where coaches and physical activity instructors are taught to teach and share leadership are needed. The aim of the current study was to evaluate the feasibility of a leadership training program to optimize it and to determine whether to proceed with its evaluation. In the leadership training program, eight Finnish novice physical activity instructors, aged 18 to 22, were taught to promote positive youth development, personal and social responsibility, and shared leadership in a physical activity context. The participants had minimal to no leadership training or experience. The training program consisted of seven meetings totaling 20 h. Helllison's teaching personal and social responsibility (TPSR) model was the theoretical and practical framework of the training program. Feasibility of the leadership training program was evaluated across four domains of an evidence-based framework: demand, practicality, acceptability, and implementation fidelity. Data of the current complex intervention were collected with application videos, questionnaires, researcher's log, lesson plans, video recordings, and a semi-structured focus group interview. The quantitative data were analyzed using descriptive statistics and the qualitative data using deductive and inductive content analysis. There was a demand for the leadership training program. The training program was perceived as practical and highly acceptable by the novice instructors and the trainers, and implemented with fidelity, indicating high overall feasibility. No implementation issues were found. Consequently, the current leadership training program has a high probability of efficacy and can be accepted for further evaluation.Peer reviewe
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