27 research outputs found

    Impact of Climate Change on Selected Physiological Parameters of Polypedates Cruciger (Common Hourglass Tree Frog)

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    Increased temperature and atmospheric CO2 concentration leading to acidification of water bodies are major attributes of climate change. Amphibians are known to be highly-sensitive to climate change. Accordingly, the objective of this study was to determine the chronic physiological responses of Polypedates cruciger to climate change based on continuous exposure to elevated temperature and CO2-induced acidification from early-larval to adult stages. Newly-hatched tadpoles of Polypedates cruciger were allocated to treatment tanks containing de-chlorinated tap water and acclimatized for two weeks. The experimental treatments were two elevated temperatures (E32 and E34), one elevated CO2 treatment (ECO2) treatment and a Control at ambient temperature and CO2. In E32 and E34, water temperatures were elevated up to 32±0.5o C and 34±0.5o C at ambient CO2 to represent predicted warming under Representative Concentration Pathway (RCP) 8.5 (E34) and RCP 2.6 (E32). In ECO2, CO2 in water was elevated to maintain its pH between 5.5 and 5.6±0.1 to represent the range predicted by RCPs 8.5 and 2.6 respectively. Each treatment was triplicated with 15 tadpoles in each. The experiment continued until the tadpoles reached Gosner Stage 42. Mean concentration of ammonia released per individual was (AmRel) was calculated using ammonia concentration of each tank, determined by Phenate method. AmRel of E34 and E32 were not significantly different from the Control. AmRel of ECO2 was significantly higher than the Control during the first two weeks however, the opposite was observed during the rest of experiment. AmRel of all treatments was reduced during metamorphosis and showed weekly variations, with E34 treatment showing the highest variation. Although statistically insignificant, the mean catalase activity was greater in ECO2, while the overall swimming speed was lower in all treatments, compared to control. Lysozyme activity of tadpoles was significantly greater in ECO2 compared to Control. The number of leukocytes in 2000 erythrocytes was significantly different among ECO2, E32 and the Control, with highest and lowest values being recorded from the Control and ECO2 respectively. Deformities (oedema, tail kink, pale pigmentation) were most abundant in E32. Results showed that temperature and CO2 elevations predicted under even the most eco-friendly scenario of RCP2.6 (E32) can affect the physiology of Polypedates cruciger. In conclusion, the abundance of deformities and physiological parameters such as ammonia excretion, swimming activity, catalase enzyme activity and immunity in terms of lysozyme activity and WBC levels of Polypedates cruciger are affected by predicted temperature and CO2 increases attributed to future climate change.Keywords: Elevated temperature and CO2, Reduced pH, Ammonia, Catalase, Lysozym

    Search for Gravitational Wave Bursts from Six Magnetars

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    Soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are thought to be magnetars: neutron stars powered by extreme magnetic fields. These rare objects are characterized by repeated and sometimes spectacular gamma-ray bursts. The burst mechanism might involve crustal fractures and excitation of non-radial modes which would emit gravitational waves (GWs). We present the results of a search for GW bursts from six galactic magnetars that is sensitive to neutron star f-modes, thought to be the most efficient GW emitting oscillatory modes in compact stars. One of them, SGR 0501+4516, is likely similar to 1 kpc from Earth, an order of magnitude closer than magnetars targeted in previous GW searches. A second, AXP 1E 1547.0-5408, gave a burst with an estimated isotropic energy >10(44) erg which is comparable to the giant flares. We find no evidence of GWs associated with a sample of 1279 electromagnetic triggers from six magnetars occurring between 2006 November and 2009 June, in GW data from the LIGO, Virgo, and GEO600 detectors. Our lowest model-dependent GW emission energy upper limits for band-and time-limited white noise bursts in the detector sensitive band, and for f-mode ringdowns (at 1090 Hz), are 3.0 x 10(44)d(1)(2) erg and 1.4 x 10(47)d(1)(2) erg, respectively, where d(1) = d(0501)/1 kpc and d(0501) is the distance to SGR 0501+4516. These limits on GW emission from f-modes are an order of magnitude lower than any previous, and approach the range of electromagnetic energies seen in SGR giant flares for the first time.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyItalian Istituto Nazionale di Fisica NucleareFrench Centre National de la Recherche ScientifiqueAustralian Research CouncilCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Educacion y CienciaConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsFoundation for Fundamental Research on Matter supported by the Netherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFoundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space Administration NNH07ZDA001-GLASTCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationRussian Space AgencyRFBR 09-02-00166aIPN JPL Y503559 (Odyssey), NASA NNG06GH00G, NASA NNX07AM42G, NASA NNX08AC89G (INTEGRAL), NASA NNG06GI896, NASA NNX07AJ65G, NASA NNX08AN23G (Swift), NASA NNX07AR71G (MESSENGER), NASA NNX06AI36G, NASA NNX08AB84G, NASA NNX08AZ85G (Suzaku), NASA NNX09AU03G (Fermi)Astronom

    Implications For The Origin Of GRB 051103 From LIGO Observations

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    We present the results of a LIGO search for gravitational waves (GWs) associated with GRB 051103, a short-duration hard-spectrum gamma-ray burst (GRB) whose electromagnetically determined sky position is coincident with the spiral galaxy M81, which is 3.6 Mpc from Earth. Possible progenitors for short-hard GRBs include compact object mergers and soft gamma repeater (SGR) giant flares. A merger progenitor would produce a characteristic GW signal that should be detectable at the distance of M81, while GW emission from an SGR is not expected to be detectable at that distance. We found no evidence of a GW signal associated with GRB 051103. Assuming weakly beamed gamma-ray emission with a jet semi-angle of 30 deg we exclude a binary neutron star merger in M81 as the progenitor with a confidence of 98%. Neutron star-black hole mergers are excluded with > 99% confidence. If the event occurred in M81 our findings support the the hypothesis that GRB 051103 was due to an SGR giant flare, making it the most distant extragalactic magnetar observed to date.Comment: 8 pages, 3 figures. For a repository of data used in the publication, go to: https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=15166 . Also see the announcement for this paper on ligo.org at: http://www.ligo.org/science/Publication-GRB051103/index.ph

    Measurement of ZZ production in leptonic final states at {\surd}s of 1.96 TeV at CDF

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    In this paper we present a precise measurement of the total ZZ production cross section in pp collisions at {\surd}s= 1.96 TeV, using data collected with the CDF II detector corresponding to an integrated luminosity of approximately 6 fb-1. The result is obtained by combining separate measurements in the four-charged (lll'l'), and two-charged-lepton and two-neutral-lepton (llvv) decay modes of the Z. The combined measured cross section for pp {\to} ZZ is 1.64^(+0.44)_(-0.38) pb. This is the most precise measurement of the ZZ production cross section in 1.96 TeV pp collisions to date.Comment: submitted to Phys. Rev. Let

    Management control systems and business performance: Evidence from Sri Lankan apparel industry

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    Purpose: The objective of this study is to explore the types and nature of management control practices and how they influence the business performance of two large apparel manufacturing companies in Sri Lanka. Research methodology: The research uses in-depth multiple case-study approaches based on a Sri Lankan apparel manufacturing company. Data is collected using interviews, participant observations, and documentary evidence. To achieve the objectives, thematic analysis is used as the analysis tool. Results: The findings of the study revealed that the existence of tight, strong, impactful, and effective MCSs (Management Control Systems) leads to both high sales volume and also elevates the annual growth of sales of two main apparel companies in Sri Lanka. Moreover, it is found that the effective placement and use of MCSs have a considerable influence on the profitability of the case companies. Limitations: The main limitation of this study is that it only focuses on two apparel exporting companies in the Sri Lankan apparel industry. Further, this research is a case study-based qualitative research where the inherent shortcomings of any such research are unavoidable where the personal traits of individuals as they place more significance on personal beliefs, opinions, and judgments than the results. Similarly, there is no articulated way to analyze qualitative data in an arithmetical manner. Contribution: This study contributes to the management discipline in the apparel industry in Sri Lanka and steers the Sri Lankan economy in a positive direction, as the research keeps an eye on the apparel industry at large

    A Preliminary Study on the Relationship between Arthropod Diversity and Vegetation Diversity in Four Contrasting Ecosystems in Hanthana Mountain Range of Sri Lanka, during the Post-Monsoon Dry Season

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    This study assesses the relationship between arthropod and vegetation diversity in four ecosystems with different types of vegetation, during a post-monsoonal season. We determined the arthropod diversity in vegetation surrounding an aquatic environment (AQ), a broad-leaved wet, evergreen forest ecosystem (BL), a Pinus caribaea monoculture plantation (PN), and a Pinus plantation artificially enriched with indigenous broad-leaved tree species (PNEN) located in the Hanthana mountain range, Sri Lanka. Arthropods randomly sampled from three randomly selected sites (5 m × 5 m) of each ecosystem were identified up to the highest possible taxa using standard identification keys. Woody and herbal vegetation was identified via a plant census. Arthropod and vegetation diversities were computed separately for each site using the Shannon–Wiener Index (H). Arthropods of 68 species and 43 families were found. AQ had the greatest arthropod diversity (H = 2.642), dominated by Olios spp., followed by BL (H = 2.444), dominated by a tettigonid species, Oxytate spp. and Psechrus spp. PN was third (H = 1.411), dominated by Dicaldispa spp. PNEN had the lowest (H = 1.3500), dominated by an ant species. Contrastingly, PNEN had the highest plant diversity (H = 2.614) and PN, the lowest (H = 0.879). In AQ, BL, and PN, the arthropod diversity was linearly dependent on plant diversity (R2 = 0.423, p ≤ 0.001), whereas it was not so when PNEN was also included (R2 = 0.008, p ≤ 0.001). This shows that higher plant diversity contributes to greater arthropod diversity in ecosystems where human intervention is minimal. But this pattern was not visible in PNEN, which is an artificially created ecosystem

    Isolated follicle stimulated hormone deficiency in male: case report

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    Abstract Background Recent rapid advances in assisted reproductive health technologies enables couples with subfertility to conceive through various intervention. Majority of treatment modalities target the female partner. However it is important to identify and treat male factor subfertility right at the outset. We report a case of isolated follicle stimulating hormone deficiency resulting in azoospermia and primary subfertility. Case presentation A 28 year otherwise healthy male presented with primary subfertility with a healthy female counterpart. He was found to have non obstructive azoospermia with low seminal fluid volume. He had normal external genitalia and potency with increased libido. Further evaluation revealed an isolated deficiency of follicle stimulating hormone with elevated testosterone levels. His luteinizing hormone and prolactin levels were normal. Contrast enhanced CT scan of chest, abdomen and pelvis and MRI scan of the pituitary fossa were normal too. Conclusion In the era of modern reproductive technology it is important to further evaluate males with non-obstructive azoospermia to detect underlying gonadotropin deficiency

    Wild Sri Lankan elephants retreat from the sound of disturbed Asian honey bees

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    Asian elephants (Elephas maximus) are threatened primarily by habitat loss and human–elephant conflict. In addition to establishing protected areas and corridors for wildlife, empowering farmers to protect their crops is crucial for Asian elephant conservation [1,2]. Elephants can habituate to artificial deterrents, hence natural biological alternatives are of great interest [2,3]. African elephants (Loxodonta africana) avoid African honey bees (Apis mellifera scutellata), inspiring ‘beehive fences’ as a successful means of small-scale crop protection [4,5]. Here, we used a recording of a disturbed hive of cavity-dwelling Asian honey bees (Apis cerana indica) and conducted sound playbacks to 120 wild elephants in 28 different groups resting under trees in Uda Walawe National Park in Sri Lanka. Elephants responded by moving significantly further away from their resting site in bee playback trials compared to controls. Elephants also increased vocalization rates, as well as investigative and reassurance behaviours in response to bee sounds, but did not display dusting or headshaking behaviour

    Wild Sri Lankan elephants retreat from the sound of disturbed Asian honey bees

    No full text
    Asian elephants (Elephas maximus) are threatened primarily by habitat loss and human–elephant conflict. In addition to establishing protected areas and corridors for wildlife, empowering farmers to protect their crops is crucial for Asian elephant conservation [1,2]. Elephants can habituate to artificial deterrents, hence natural biological alternatives are of great interest [2,3]. African elephants (Loxodonta africana) avoid African honey bees (Apis mellifera scutellata), inspiring ‘beehive fences’ as a successful means of small-scale crop protection [4,5]. Here, we used a recording of a disturbed hive of cavity-dwelling Asian honey bees (Apis cerana indica) and conducted sound playbacks to 120 wild elephants in 28 different groups resting under trees in Uda Walawe National Park in Sri Lanka. Elephants responded by moving significantly further away from their resting site in bee playback trials compared to controls. Elephants also increased vocalization rates, as well as investigative and reassurance behaviours in response to bee sounds, but did not display dusting or headshaking behaviour

    Sustainable Claisen-Schmidt chalcone synthesis catalysed by plasma-recovered MgO nanosheets from seawater

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    Chalcones enable the biosynthesis of flavonoids which protect plants from infections and parasites and have emerged as valuable medicines against diverse human diseases. The common way to synthesize chalcones through the homogeneous catalytic Claisen-Schmidt condensation reaction is compromised from difficult catalyst recovery, waste generation, side reactions, and low yield. As a solution, solid base catalysts are developed as a green catalytic process. It is still a major challenge to synthesize highly active heterogeneous catalysts with a quick, simple, sustainable, and economical approach in the chalcone synthesis. To address these issues, a simple and sustainable synthesis of chalcones has been accomplished here by the solvent-free Claisen-Schmidt condensation reaction using magnesium oxide (MgO) nanosheets as the catalyst. The heterogeneous two-dimensional (2D) MgO catalyst was synthesized using salt recovered from inexhaustible seawater, using an atmospheric pressure plasma (APP)-assisted method making the whole method sustainable and potentially economically feasible. The catalytic activity of the 2D nanosheets was compared with irregular MgO nanoparticles. Irregular MgO showed 25% of benzaldehyde and 10% of acetophenone conversion, while 2D MgO showed >99% of conversion of both reactants with a product selectivity of 100%, while no products were formed in the absence of a catalyst. The effect of substituent groups on the benzaldehyde moiety on the catalytic activity was also analysed. The prepared 2D MgO catalyst showed reusability up to three cycles without any significant loss in the catalytic activity.</p
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