1,195 research outputs found

    The Use of Fish Scale Hormone Concentrations as a Non-Lethal Biomonitoring Tool in Teleost Fishes

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    Teleost fish serve as an essential resource to the human population and thus their conservation is of extreme importance. In an effort to monitor the effects of anthropogenic activity in fishes, the quantification of cortisol as an indicator of increased stress is often employed. Cortisol is a glucocorticoid released by the hypothalamic-pituitary-inter-renal (HPI) axis in fishes in response to a stressor. Cortisol alongside other stress hormones then serves to equip the fish with the resources required to overcome the stressor. However, if this response is repeatedly engaged the state of stress can change from acute to chronic often resulting in adverse effects. Fish scales are durable calcified structures that can be sampled non-lethally from many fish species. Recently the fish scale has been shown to incorporate and store cortisol for long periods of time allowing it to serve as a medium for long-term stress assessments. This has now been accomplished in eight species of fish and recent studies have provided promising evidence for the use of fish scale cortisol concentration in the evaluation of a variety of chronic stressors. However, cortisol quantification alone is limited in its ability to diagnose chronic stress and thus my thesis research sought to investigate additional stress related hormones within the scale. The first two experiments quantified scale cortisol, cortisone and DHEA after a 14-day randomized stress protocol. In goldfish this resulted in significantly elevated circulating cortisol and cortisone and while these hormones were only somewhat elevated in the scales the scale cortisol:DHEA ratio was significantly elevated in stressed goldfish. By contrast, the same stress protocol significantly elevated scale but not serum concentrations of all three hormones in rainbow trout in the second experiment. The third experiment included cortisol, progesterone, testosterone and 11-ketotestosterone to allow for the evaluation of both chronic stress and associated effects on reproduction. Artificial elevation of cortisol, progesterone and testosterone using coconut oil implants produced many interactions both among different hormones and among the two sample media: serum and scale. It was found that injected progesterone and testosterone were converted to 11-ketotestosterone, the primary androgen in teleost fishes and that well-studied negative interactions between cortisol and androgens are also relevant to scale hormone analyses. While the roles and relationships between the hormones explored in these experiments as well as their partitioning from blood to scale still requires further investigation, fish scale hormone concentrations appear to provide a unique and useful tool for future biomonitoring efforts

    Shoulder pain due to cervical radiculopathy: an underestimated long-term complication of herpes zoster virus reactivation?

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    Purpose To evaluate if herpes zoster virus (HZV) reactivation may be considered in the aetiology of cervical radiculopathy. Methods The study group was composed of 110 patients (52 M-58F;mean age ± SD:46.5 ± 6.12; range:40-73) with a clinical diagnosis of cervical radiculopathy. Patients with signs of chronic damage on neurophysiological studies were submitted to an X-ray and to an MRI of the cervical spine in order to clarify the cause of the cervical radiculopathy and were investigated for a possible reactivation of HZV; HZV reactivation was considered as “recent” or “antique” if it occurs within or after 24 months from the onset of symptoms, respectively. Data were submitted to statistics. Results Thirty-eight patients (34,5%,16 M-22F) had a history of HZV reactivation: four (2 M-2F) were “recent” and 34 (14 M-20F) were “antique”. In 68 of 110 participants (61,8%,30 M-38F), pathological signs on X-ray and/or MRI of the cervical spine appeared; in the remaining 42 (38,2%,22 M-20F) X-ray and MRI resulted as negative. Among patients with HZV reactivation, seven (18,4%) had a “positive” X-ray-MRI while in 31 (81,6%) the instrumental exams were considered as negative. The prevalence of “antique” HZV reactivations was statistically greater in the group of patients with no pathological signs on X-ray/MRI of the cervical spine with respect to the group with a pathological instrumental exam (p < 0.01). Conclusions It may be useful to investigate the presence of a positive history of HZV reactivation and to consider it as a long-term complication of a cervical root inflammation especially in patients in which X-ray and MRI of the cervical spine did not show pathological findings

    Age- and Sex-Specific Mortality Patterns in an Emerging Wildlife Epidemic: The Phocine Distemper in European Harbour Seals

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    Analyses of the dynamics of diseases in wild populations typically assume all individuals to be identical. However, profound effects on the long-term impact on the host population can be expected if the disease has age and sex dependent dynamics. The Phocine Distemper Virus (PDV) caused two mass mortalities in European harbour seals in 1988 and in 2002. We show the mortality patterns were highly age specific on both occasions, where young of the year and adult (>4 yrs) animals suffered extremely high mortality, and sub-adult seals (1–3 yrs) of both sexes experienced low mortality. Consequently, genetic differences cannot have played a main role explaining why some seals survived and some did not in the study region, since parents had higher mortality levels than their progeny. Furthermore, there was a conspicuous absence of animals older than 14 years among the victims in 2002, which strongly indicates that the survivors from the previous disease outbreak in 1988 had acquired and maintained immunity to PDV. These specific mortality patterns imply that contact rates and susceptibility to the disease are strongly age and sex dependent variables, underlining the need for structured epidemic models for wildlife diseases. Detailed data can thus provide crucial information about a number of vital parameters such as functional herd immunity. One of many future challenges in understanding the epidemiology of the PDV and other wildlife diseases is to reveal how immune system responses differ among animals in different stages during their life cycle. The influence of such underlying mechanisms may also explain the limited evidence for abrupt disease thresholds in wild populations

    Planning a 'slum free' Trivandrum: housing upgrade and the rescaling of urban governance in India

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    This paper examines how India’s national urban development agenda is reshaping relationships between national, State and city-level governments. JNNURM, the flagship programme that heralded a new era of urban investment in India, contained a range of key governance aspirations: linking the analysis of urban poverty to city-level planning, developing holistic housing solutions for the urban poor, and above all empowering Urban Local Bodies to re-balance relationships between State and city-level governments in favour of the latter. Here, we trace JNNURM’s implementation in Kerala’s capital city, Trivandrum (Thiruvananthapuram), where the city’s decentralised urban governance structure and use of ‘pro-poor’ institutions to implement housing upgrade programmes could have made it an exemplar of success. In practice, Trivandrum’s ‘city visioning’ exercises and the housing projects it has undertaken have fallen short of JNNURM’s lofty goals. The contradictions between empowering cities and retaining centralised control embedded within this national programme, and the unintended city-level consequences of striving for JNNURM funding success, have reshaped urban governance in ways not envisaged within policy. As a result, JNNURM has been important in rescaling governance relationships through three interlinked dynamics of problem framing, technologies of governance and the scalar strategy of driving reform ‘from above’ that together have ensured the national state’s continued influence over the practices of urban governance in India

    Visual ecology of aphids – a critical review on the role of colours in host finding

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    We review the rich literature on behavioural responses of aphids (Hemiptera: Aphididae) to stimuli of different colours. Only in one species there are adequate physiological data on spectral sensitivity to explain behaviour crisply in mechanistic terms. Because of the great interest in aphid responses to coloured targets from an evolutionary, ecological and applied perspective, there is a substantial need to expand these studies to more species of aphids, and to quantify spectral properties of stimuli rigorously. We show that aphid responses to colours, at least for some species, are likely based on a specific colour opponency mechanism, with positive input from the green domain of the spectrum and negative input from the blue and/or UV region. We further demonstrate that the usual yellow preference of aphids encountered in field experiments is not a true colour preference but involves additional brightness effects. We discuss the implications for agriculture and sensory ecology, with special respect to the recent debate on autumn leaf colouration. We illustrate that recent evolutionary theories concerning aphid–tree interactions imply far-reaching assumptions on aphid responses to colours that are not likely to hold. Finally we also discuss the implications for developing and optimising strategies of aphid control and monitoring

    In-vivo kinetics of inhaled 5-Aminolevulinic acid-Induced Protoporphyrin IX fluorescence in bronchial tissue

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    BACKGROUND: In the diagnosis of early-stage lung cancer photosensitizer-enhanced fluorescence bronchoscopy with inhaled 5-aminolevolinic acid (5-ALA) increases sensitivity when compared to white-light bronchoscopy. This investigation was to evaluate the in vivo tissue pharmacokinetics of inhaled 5-ALA within the bronchial mucosa in order to define the time optimum for its application prior to bronchoscopy. METHODS: Patients with known or suspected bronchial carcinoma were randomized to receive 200 mg 5-ALA via inhalation 1, 2, 3, 4 or 6 hours before flexible fluorescence bronchoscopy was performed. Macroscopically suspicious areas as well as areas with visually detected porphyrin fluorescence and normal control sites were measured spectroscopically. Biopsies for histopathology were obtained from suspicious areas as well as from adjacent normal areas. RESULTS: Fluorescence bronchoscopy performed in 19 patients reveals a sensitivity for malignant and premalignant changes (moderate dysplasia) which is almost twice as high as that of white-light bronchoscopy, whereas specificity is reduced. This is due to false-positive inflammatory lesions which also frequently show increased porphyrin fluorescence. Malignant and premalignant alterations produced fluorescence values that are up to 5 times higher than those of normal tissue. According to the pharmacokinetics of porphyrin fluorescence measured by spectroscopy, the optimum time range for 5-ALA application is 80–270 min prior to fluorescence bronchoscopy, with an optimum at 160 min. CONCLUSION: According to our results we propose inhalation of 5-ALA 160 min prior to fluorescence bronchoscopy, suggesting that this time difference provides the best tumor/normal tissue fluorescence ratio

    Poly(ADP-ribose) polymerase family member 14 (PARP14) is a novel effector of the JNK2-dependent pro-survival signal in multiple myeloma

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    Copyright @ 2013 Macmillan Publishers Limited. This is the author's accepted manuscript. The final published article is available from the link below.Regulation of cell survival is a key part of the pathogenesis of multiple myeloma (MM). Jun N-terminal kinase (JNK) signaling has been implicated in MM pathogenesis, but its function is unclear. To elucidate the role of JNK in MM, we evaluated the specific functions of the two major JNK proteins, JNK1 and JNK2. We show here that JNK2 is constitutively activated in a panel of MM cell lines and primary tumors. Using loss-of-function studies, we demonstrate that JNK2 is required for the survival of myeloma cells and constitutively suppresses JNK1-mediated apoptosis by affecting expression of poly(ADP-ribose) polymerase (PARP)14, a key regulator of B-cell survival. Strikingly, we found that PARP14 is highly expressed in myeloma plasma cells and associated with disease progression and poor survival. Overexpression of PARP14 completely rescued myeloma cells from apoptosis induced by JNK2 knockdown, indicating that PARP14 is critically involved in JNK2-dependent survival. Mechanistically, PARP14 was found to promote the survival of myeloma cells by binding and inhibiting JNK1. Moreover, inhibition of PARP14 enhances the sensitization of MM cells to anti-myeloma agents. Our findings reveal a novel regulatory pathway in myeloma cells through which JNK2 signals cell survival via PARP14, and identify PARP14 as a potential therapeutic target in myeloma.Kay Kendall Leukemia Fund, NIH, Cancer Research UK, Italian Association for Cancer Research and the Foundation for Liver Research

    Planet Populations as a Function of Stellar Properties

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    Exoplanets around different types of stars provide a window into the diverse environments in which planets form. This chapter describes the observed relations between exoplanet populations and stellar properties and how they connect to planet formation in protoplanetary disks. Giant planets occur more frequently around more metal-rich and more massive stars. These findings support the core accretion theory of planet formation, in which the cores of giant planets form more rapidly in more metal-rich and more massive protoplanetary disks. Smaller planets, those with sizes roughly between Earth and Neptune, exhibit different scaling relations with stellar properties. These planets are found around stars with a wide range of metallicities and occur more frequently around lower mass stars. This indicates that planet formation takes place in a wide range of environments, yet it is not clear why planets form more efficiently around low mass stars. Going forward, exoplanet surveys targeting M dwarfs will characterize the exoplanet population around the lowest mass stars. In combination with ongoing stellar characterization, this will help us understand the formation of planets in a large range of environments.Comment: Accepted for Publication in the Handbook of Exoplanet

    Lattice QCD at finite temperature: a status report

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    Karsch F. Lattice QCD at finite temperature: a status report. Zeitschrift für Physik, C: Particles and Fields. 1988;38(1-2):147-155.We analyze the status of numerical simulation of QCD at finite temperature. Emphasis is put on quantitative predictions emerging from lattice calculations that may be tested in heavy ion experiments. Recent results on the chiral phase transition, thermodynamics of the quark gluon plasma phase and various screening lengths are discussed. Presented at the 6th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions-Quark Matter 1987, 24–28 August 1987, Nordkirchen, Federal Republic of Germany

    Operator theory and function theory in Drury-Arveson space and its quotients

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    The Drury-Arveson space Hd2H^2_d, also known as symmetric Fock space or the dd-shift space, is a Hilbert function space that has a natural dd-tuple of operators acting on it, which gives it the structure of a Hilbert module. This survey aims to introduce the Drury-Arveson space, to give a panoramic view of the main operator theoretic and function theoretic aspects of this space, and to describe the universal role that it plays in multivariable operator theory and in Pick interpolation theory.Comment: Final version (to appear in Handbook of Operator Theory); 42 page
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