427 research outputs found

    A Frequency Tuning Method for a Planar Inverted-F Antenna

    Get PDF
    A novel method is presented for electrically tuning the frequency of a planar inverted-F antenna (PIFA). A tuning circuit, comprising an RF switch and discrete passive components, has been completely integrated into the antenna element, which is thus free of dc wires. The proposed tuning method has been demonstrated with a dual-band PIFA capable of operating in four frequency bands. The antenna covers the GSM850, GSM900, GSM1800, PCS1900 and UNITS frequency ranges with over 40% total efficiency. The impact of the tuning circuit on the antenna's efficiency and radiation pattern have been experimentally studied through comparison with the performance of a reference antenna not incorporating the tuning circuit. The proposed frequency tuning concept can be extended to more complex PIFA structures as well as other types of antennas to give enhanced electrical performance.</p

    JNK1 controls adult hippocampal neurogenesis and imposes cell-autonomous control of anxiety behaviour from the neurogenic niche

    Get PDF
    Promoting adult hippocampal neurogenesis is expected to induce neuroplastic changes that improve mood and alleviate anxiety. However, the underlying mechanisms remain largely unknown and the hypothesis itself is controversial. Here we show that mice lacking Jnk1, or c-Jun N-terminal kinase (JNK) inhibitor-treated mice, display increased neurogenesis in adult hippocampus characterized by enhanced cell proliferation and survival, and increased maturation in the ventral region. Correspondingly, anxiety behaviour is reduced in a battery of tests, except when neurogenesis is prevented by AraC treatment. Using engineered retroviruses, we show that exclusive inhibition of JNK in adult-born granule cells alleviates anxiety and reduces depressive-like behaviour. These data validate the neurogenesis hypothesis of anxiety. Moreover, they establish a causal role for JNK in the hippocampal neurogenic niche and anxiety behaviour, and advocate targeting of JNK as an avenue for novel therapies against affective disorders.Peer reviewe

    Effect of natural weathering on water absorption and pore size distribution in thermally modified wood determined by nuclear magnetic resonance

    Get PDF
    Funder: Teollisuusneuvos Heikki Väänänen's FundFunder: International Thermowood AssociationFunder: Quantum Institute, University of OuluAbstractThermally modified wood (TMW) is widely used in outdoor applications due to its advanced properties towards weathering stresses. Although the structure changes of TMW from weather factors have been reported, investigation of the quantitative analysis of water states and cell wall structure of TMW after weathering is limited. In this work, the amount of bound water, fiber saturation point (FSP), cell wall pores, and free water distribution of thermally modified Scots pine, Norway spruce, and European ash were measured before and after a 2-year natural weathering via NMR relaxometry, cryoporometry, and magnetic resonance imaging. The results show that weathering increased T2 relaxation time of lumens, indicating the degradation of tracheids and vessels, especially in TMW compared to unmodified wood. The amounts of bound water, FSP value, and cell wall pores were increased after weathering; however, an increase in thermal modification intensity resulted in lower FSP and limited the increase in number of pores. In summary, TMW showed better performance than unmodified wood after weathering.</jats:p

    Expression of Hyaluronan Synthases (HAS1–3) and Hyaluronidases (HYAL1–2) in Serous Ovarian Carcinomas: Inverse Correlation between HYAL1 and Hyaluronan Content

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Hyaluronan, a tumor promoting extracellular matrix polysaccharide, is elevated in malignant epithelial ovarian tumors, and associates with an unfavorable prognosis. To explore possible contributors to the accumulation of hyaluronan, we examined the expression of hyaluronan synthases (<it>HAS1</it>, <it>HAS2 </it>and <it>HAS3</it>) and hyaluronidases (<it>HYAL1 </it>and <it>HYAL2</it>), correlated with hyaluronidase enzyme activity hyaluronan content and HAS1–3 immunoreactivity.</p> <p>Methods</p> <p>Normal ovaries (n = 5) and 34 serous epithelial ovarian tumors, divided into 4 groups: malignant grades 1+2 (n = 10); malignant grade 3 (n = 10); borderline (n = 4) and benign epithelial tumors (n = 10), were analyzed for mRNA by real-time RT-PCR and compared to hyaluronidase activity, hyaluronan staining, and HAS1–3 immunoreactivity in tissue sections of the same specimens.</p> <p>Results</p> <p>The levels of <it>HAS2 </it>and <it>HAS3 </it>mRNA (<it>HAS1 </it>was low or absent), were not consistently increased in the carcinomas, and were not significantly correlated with HAS protein or hyaluronan accumulation in individual samples. Instead, the median of <it>HYAL1 </it>mRNA level was 69% lower in grade 3 serous ovarian cancers compared to normal ovaries (P = 0.01). The expression of <it>HYAL1</it>, but not <it>HYAL2</it>, significantly correlated with the enzymatic activity of tissue hyaluronidases (r = 0.5; P = 0.006). An inverse correlation was noted between <it>HYAL1 </it>mRNA and the intensity of hyaluronan staining of the corresponding tissue sections (r = -0.4; P = 0.025).</p> <p>Conclusion</p> <p>The results indicate that in serous epithelial ovarian malignancies <it>HAS </it>expression is not consistently elevated but <it>HYAL1 </it>expression is significantly reduced and correlates with the accumulation of hyaluronan. (233 words)</p

    Enterprise Education Competitions: A Theoretically Flawed Intervention?

    Get PDF
    The demand for including enterprise in the education system, at all levels and for all pupils is now a global phenomenon. Within this context, the use of competitions and competitive learning activities is presented as a popular and effective vehicle for learning. The purpose of this chapter is to illustrate how a realist method of enquiry – which utilises theory as the unit of analysis – can shed new light on the assumed and unintended outcomes of enterprise education competitions. The case developed here is that there are inherent flaws in assuming that competitions will ‘work’ in the ways set out in policy and guidance. Some of the most prevalent stated outcomes – that competitions will motivate and reward young people, that they will enable the development of entrepreneurial skills, and that learners will be inspired by their peers – are challenged by theory from psychology and education. The issue at stake is that the expansion of enterprise education policy into primary and secondary education increases the likelihood that more learners will be sheep dipped in competitions, and competitive activities, without a clear recognition of the potential unintended effects. In this chapter, we employ a realist-informed approach to critically evaluate the theoretical basis that underpins the use of competitions and competitive learning activities in school-based enterprise education. We believe that our findings and subsequent recommendations will provide those who promote and practice the use of competitions with a richer, more sophisticated picture of the potential flaws within such activities.Peer reviewedFinal Published versio

    A good practice guide to managing human resource s in regional SMEs.

    Get PDF
    This publication is intended not only for small and medium-sized enterprises, but also for those who are in charge of human resources and are looking for inspiration on how to acquire and retain them or wish to educate themselves in this field further. The publication focuses on practice; it details the crucial challenges of HR in terms of literature, as well as practical case studies. And it is this focus - this lead in human resource management - that can give many companies a competitive edge and advance of others which have not yet gained that knowledge
    corecore