254 research outputs found

    The Ethical and Scientific Debate Behind Human Reproductive Cloning by Somatic Cell Nuclear Transfer

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    All humans have an innate need to reproduce, and therefore an innate need to engage in sexual activity (Benagiano, Carrara and Filippi 2010). However, reproduction today can and is frequently achieved without sexual intercourse (Benagiano, Carrara and Filippi 2010). Human reproductive cloning provides an alternate route for those who have tried assisted reproductive techniques, like in-vitro fertilization or oocyte donation, with no success. Somatic cell nuclear transfer and embryo splitting have both been explored as a means to accomplish reproductive cloning in animals, yet, the health risks associated with using these modern technological techniques remains virtually unknown (Montazer-Torbati et al 2016; Nie et al 2017; Oh et al 2015; Secher et al 2017). In addition, the potential ethical effects that human reproductive cloning can have upon the resulting clones is also in question (Mameli 2007; Shapshay 2012). Human reproductive cloning can lead down a dangerous path of reducing humans to an object to be used for the sole purpose of benefitting their parent (Shapshay 2012). Additionally, human reproductive cloning can cause the resulting clones to feel as if their individuality is in question due to the fact that they will share their DNA with another already existing individual (Mameli 2007). Nevertheless, proponents of human reproductive cloning have argued that the right to self-determination will prevent the clones produced using this method from feeling that their autonomy has been undermined using research investigating the opinions of monozygotic twins on this topic (Havastad 2010; Prainsack, Cherkas, and Spector 2007). Evidentially, human reproductive cloning has been highly debated in today’s society due to the scientific and ethical aspects that could occur as a result. Considering the potential risks that human reproductive cloning can have upon not only the resulting individual but also society as a whole, human reproductive cloning should be prohibited. Future research should be conducted investigating possible alternate assisted reproductive techniques with higher success rates, views of monozygotic twins on human reproductive cloning, and health risks on animals cloned using somatic cell nuclear transfer

    Vancomycin minimum inhibitory concentration is not a substitute for clinical judgment: Response to healthcare-associated ventriculitis and meningitis

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    To the Editor—We read with interest the new clinical practice guideline for healthcare-associated ventriculitis and meningitis published in Clinical Infectious Diseases [1]. The guideline recommends consideration of alternative therapies for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) meningitis and ventriculitis for isolates with a vancomycin minimum in-hibitory concentration (MIC) ≥1μg/mL. We believe this recommendation places inappropriate emphasis on a single determinant of antimicrobial therapy that has uncertain clinical relevance and variable accuracy depending on the antimicrobial susceptibility testing (AST) method used. This may lead clinicians to use less well-evidenced strategies in cases likely to respond to vancomycin

    A Baker\u27s Dozen of Top Antimicrobial Stewardship Intervention Publications in 2017

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    With an increasing number of antimicrobial stewardship-related articles published each year, attempting to stay current is challenging. The Southeastern Research Group Endeavor (SERGE-45) identified antimicrobial stewardship-related peer-reviewed literature that detailed an actionable intervention for 2017. The top 13 publications were selected using a modified Delphi technique. These manuscripts were reviewed to highlight the actionable intervention used by antimicrobial stewardship programs to provide key stewardship literature for training and teaching and identify potential intervention opportunities within their institutions

    A Baker\u27s Dozen of Top Antimicrobial Stewardship Intervention Publications in 2018

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    © The Author(s) 2019 Phytochemical investigation of methanolic extract of Limonium leptophyllum (Plumbaginaceae), led to the isolation of 1 new isoflavonoid with a rare 5-membered dihydrofuran ring (1, leptoisoflavone A) and 8 known compounds. The known isolated compounds were identified as euchrenone b9 (2), auriculasin (3), kaempferol (4), avicularoside (5), myrice-tin-3-arabinoside (6), trans-N-feruloyltyramine (7), trans-N-caffeoyltyramine (8), and β-sitosterol (9). The crude methanolic extract exhibited moderate activity toward endocannabinoid receptors. Auriculasin (3) showed activity toward cannabinoid receptor type 1 (86.7% displacement with IC50 8.92 μM)

    A Baker\u27s Dozen of Top Antimicrobial Stewardship Intervention Publications in 2017

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    With an increasing number of antimicrobial stewardship-related articles published each year, attempting to stay current is challenging. The Southeastern Research Group Endeavor (SERGE-45) identified antimicrobial stewardship-related peer-reviewed literature that detailed an actionable intervention for 2017. The top 13 publications were selected using a modified Delphi technique. These manuscripts were reviewed to highlight the actionable intervention used by antimicrobial stewardship programs to provide key stewardship literature for training and teaching and identify potential intervention opportunities within their institutions

    Ca2+-Dependent Phosphorylation of RyR2 Can Uncouple Channel Gating from Direct Cytosolic Ca2+ Regulation

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    Phosphorylation of the cardiac ryanodine receptor (RyR2) is thought to be important not only for normal cardiac excitation-contraction coupling but also in exacerbating abnormalities in Ca2+ homeostasis in heart failure. Linking phosphorylation to specific changes in the single-channel function of RyR2 has proved very difficult, yielding much controversy within the field. We therefore investigated the mechanistic changes that take place at the single-channel level after phosphorylating RyR2 and, in particular, the idea that PKA-dependent phosphorylation increases RyR2 sensitivity to cytosolic Ca2+. We show that hyperphosphorylation by exogenous PKA increases open probability (Po) but, crucially, RyR2 becomes uncoupled from the influence of cytosolic Ca2+; lowering [Ca2+] to subactivating levels no longer closes the channels. Phosphatase (PP1) treatment reverses these gating changes, returning the channels to a Ca2+-sensitive mode of gating. We additionally found that cytosolic incubation with Mg2+/ATP in the absence of exogenously added kinase could phosphorylate RyR2 in approximately 50% of channels, thereby indicating that an endogenous kinase incorporates into the bilayer together with RyR2. Channels activated by the endogenous kinase exhibited identical changes in gating behavior to those activated by exogenous PKA, including uncoupling from the influence of cytosolic Ca2+. We show that the endogenous kinase is both Ca2+-dependent and sensitive to inhibitors of PKC. Moreover, the Ca2+-dependent, endogenous kinase–induced changes in RyR2 gating do not appear to be related to phosphorylation of serine-2809. Further work is required to investigate the identity and physiological role of this Ca2+-dependent endogenous kinase that can uncouple RyR2 gating from direct cytosolic Ca2+ regulation

    All-sky search for periodic gravitational waves in LIGO S4 data

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    We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1000 Hz and with the frequency's time derivative in the range -1.0E-8 Hz/s to zero. Data from the fourth LIGO science run (S4) have been used in this search. Three different semi-coherent methods of transforming and summing strain power from Short Fourier Transforms (SFTs) of the calibrated data have been used. The first, known as "StackSlide", averages normalized power from each SFT. A "weighted Hough" scheme is also developed and used, and which also allows for a multi-interferometer search. The third method, known as "PowerFlux", is a variant of the StackSlide method in which the power is weighted before summing. In both the weighted Hough and PowerFlux methods, the weights are chosen according to the noise and detector antenna-pattern to maximize the signal-to-noise ratio. The respective advantages and disadvantages of these methods are discussed. Observing no evidence of periodic gravitational radiation, we report upper limits; we interpret these as limits on this radiation from isolated rotating neutron stars. The best population-based upper limit with 95% confidence on the gravitational-wave strain amplitude, found for simulated sources distributed isotropically across the sky and with isotropically distributed spin-axes, is 4.28E-24 (near 140 Hz). Strict upper limits are also obtained for small patches on the sky for best-case and worst-case inclinations of the spin axes.Comment: 39 pages, 41 figures An error was found in the computation of the C parameter defined in equation 44 which led to its overestimate by 2^(1/4). The correct values for the multi-interferometer, H1 and L1 analyses are 9.2, 9.7, and 9.3, respectively. Figure 32 has been updated accordingly. None of the upper limits presented in the paper were affecte

    Search for gravitational waves from binary inspirals in S3 and S4 LIGO data

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    We report on a search for gravitational waves from the coalescence of compact binaries during the third and fourth LIGO science runs. The search focused on gravitational waves generated during the inspiral phase of the binary evolution. In our analysis, we considered three categories of compact binary systems, ordered by mass: (i) primordial black hole binaries with masses in the range 0.35 M(sun) < m1, m2 < 1.0 M(sun), (ii) binary neutron stars with masses in the range 1.0 M(sun) < m1, m2 < 3.0 M(sun), and (iii) binary black holes with masses in the range 3.0 M(sun)< m1, m2 < m_(max) with the additional constraint m1+ m2 < m_(max), where m_(max) was set to 40.0 M(sun) and 80.0 M(sun) in the third and fourth science runs, respectively. Although the detectors could probe to distances as far as tens of Mpc, no gravitational-wave signals were identified in the 1364 hours of data we analyzed. Assuming a binary population with a Gaussian distribution around 0.75-0.75 M(sun), 1.4-1.4 M(sun), and 5.0-5.0 M(sun), we derived 90%-confidence upper limit rates of 4.9 yr^(-1) L10^(-1) for primordial black hole binaries, 1.2 yr^(-1) L10^(-1) for binary neutron stars, and 0.5 yr^(-1) L10^(-1) for stellar mass binary black holes, where L10 is 10^(10) times the blue light luminosity of the Sun.Comment: 12 pages, 11 figure

    Searching for a Stochastic Background of Gravitational Waves with LIGO

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    The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed the fourth science run, S4, with significantly improved interferometer sensitivities with respect to previous runs. Using data acquired during this science run, we place a limit on the amplitude of a stochastic background of gravitational waves. For a frequency independent spectrum, the new limit is ΩGW<6.5×105\Omega_{\rm GW} < 6.5 \times 10^{-5}. This is currently the most sensitive result in the frequency range 51-150 Hz, with a factor of 13 improvement over the previous LIGO result. We discuss complementarity of the new result with other constraints on a stochastic background of gravitational waves, and we investigate implications of the new result for different models of this background.Comment: 37 pages, 16 figure

    A Joint Search for Gravitational Wave Bursts with AURIGA and LIGO

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    The first simultaneous operation of the AURIGA detector and the LIGO observatory was an opportunity to explore real data, joint analysis methods between two very different types of gravitational wave detectors: resonant bars and interferometers. This paper describes a coincident gravitational wave burst search, where data from the LIGO interferometers are cross-correlated at the time of AURIGA candidate events to identify coherent transients. The analysis pipeline is tuned with two thresholds, on the signal-to-noise ratio of AURIGA candidate events and on the significance of the cross-correlation test in LIGO. The false alarm rate is estimated by introducing time shifts between data sets and the network detection efficiency is measured with simulated signals with power in the narrower AURIGA band. In the absence of a detection, we discuss how to set an upper limit on the rate of gravitational waves and to interpret it according to different source models. Due to the short amount of analyzed data and to the high rate of non-Gaussian transients in the detectors noise at the time, the relevance of this study is methodological: this was the first joint search for gravitational wave bursts among detectors with such different spectral sensitivity and the first opportunity for the resonant and interferometric communities to unify languages and techniques in the pursuit of their common goal.Comment: 18 pages, IOP, 12 EPS figure
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