649 research outputs found

    Mouse cytoplasmic dynein intermediate chains: identification of new isoforms, alternative splicing and tissue distribution of transcripts

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    BACKGROUND: Intracellular transport of cargoes including organelles, vesicles, signalling molecules, protein complexes, and RNAs, is essential for normal function of eukaryotic cells. The cytoplasmic dynein complex is an important motor that moves cargos along microtubule tracks within the cell. In mammals this multiprotein complex includes dynein intermediate chains 1 and 2 which are encoded by two genes, Dync1i1 and Dync1i2. These proteins are involved in dynein cargo binding and dynein complexes with different intermediate chains bind to specific cargoes, although the mechanisms to achieve this are not known. The DYNC1I1 and DYNC1I2 proteins are translated from different splice isoforms, and specific forms of each protein are essential for the function of different dynein complexes in neurons. METHODOLOGY/PRINCIPAL FINDINGS: Here we have undertaken a systematic survey of the dynein intermediate chain splice isoforms in mouse, basing our study on mRNA expression patterns in a range of tissues, and on bioinformatics analysis of mouse, rat and human genomic and cDNA sequences. We found a complex pattern of alternative splicing of both dynein intermediate chain genes, with maximum complexity in the embryonic and adult nervous system. We have found novel transcripts, including some with orthologues in human and rat, and a new promoter and alternative non-coding exon 1 for Dync1i2. CONCLUSIONS/SIGNIFICANCE: These data, including the cloned isoforms will be essential for understanding the role of intermediate chains in the cytoplasmic dynein complex, particularly their role in cargo binding within individual tissues including different brain regions

    Hydrological impacts of climate change at catchment scale : a case study in the Grand-Duchy of Luxembourg

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    As a consequence of an increase of days with westerly atmospheric fluxes, bringing humid air masses from the Atlantic Ocean to Western Europe, important changes in the annual and seasonal distribution of rainfall have been observed over the past 150 years. Annual rainfall totals observed during the second half of the 19th century were less important than those observed during the second half of the 20th century. Moreover, during the past 50 years winter rainfall totals have significantly increased, while summer rainfall totals have been decreasing. Streamflow observations through the second half of the 20th century have shown a significant increase of winter maximum daily streamflow, in reaction to the winter rainfall increase. The modelling of the streamflow under the 19th century climatological conditions suggests that since then, the number of winter flood days has increased, while the occurrence of summer flood days has decreased. Moreover, high floods appear to have been more frequent in the second half of the 20th century

    Quantum properties of the three-mode squeezed operator: triply concurrent parametric amplifiers

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    In this paper, we study the quantum properties of the three-mode squeezed operator. This operator is constructed from the optical parametric oscillator based on the three concurrent χ(2)\chi^{(2)} nonlinearities. We give a complete treatment for this operator including the symmetric and asymmetric nonlinearities cases. The action of the operator on the number and coherent states are studied in the framework of squeezing, second-order correlation function, Cauchy-Schwartz inequality and single-mode quasiprobability function. The nonclassical effects are remarkable in all these quantities. We show that the nonclassical effects generated by the asymmetric case--for certain values of the system parameters--are greater than those of the symmetric one. This reflects the important role for the asymmetry in the system. Moreover, the system can generate different types of the Schr\"odinger-cat states.Comment: 21 pages, 14 figures; comments are most welcom

    Genetic Reconstruction of Protozoan rRNA Decoding Sites Provides a Rationale for Paromomycin Activity against Leishmania and Trypanosoma

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    Aminoglycoside antibiotics target the ribosomal decoding A-site and are active against a broad spectrum of bacteria. These compounds bind to a highly conserved stem-loop-stem structure in helix 44 of bacterial 16S rRNA. One particular aminoglycoside, paromomycin, also shows potent antiprotozoal activity and is used for the treatment of parasitic infections, e.g. by Leishmania spp. The precise drug target is, however, unclear; in particular whether aminoglycoside antibiotics target the cytosolic and/or the mitochondrial protozoan ribosome. To establish an experimental model for the study of protozoan decoding-site function, we constructed bacterial chimeric ribosomes where the central part of bacterial 16S rRNA helix 44 has been replaced by the corresponding Leishmania and Trypanosoma rRNA sequences. Relating the results from in-vitro ribosomal assays to that of in-vivo aminoglycoside activity against Trypanosoma brucei, as assessed in cell cultures and in a mouse model of infection, we conclude that aminoglycosides affect cytosolic translation while the mitochondrial ribosome of trypanosomes is not a target for aminoglycoside antibiotics

    A neural network based intelligent predictive sensor for cloudiness, solar radiation and air temperature

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    Accurate measurements of global solar radiation and atmospheric temperature, as well as the availability of the predictions of their evolution over time, are important for different areas of applications, such as agriculture, renewable energy and energy management, or thermal comfort in buildings. For this reason, an intelligent, light-weight and portable sensor was developed, using artificial neural network models as the time-series predictor mechanisms. These have been identified with the aid of a procedure based on the multi-objective genetic algorithm. As cloudiness is the most significant factor affecting the solar radiation reaching a particular location on the Earth surface, it has great impact on the performance of predictive solar radiation models for that location. This work also represents one step towards the improvement of such models by using ground-to-sky hemispherical colour digital images as a means to estimate cloudiness by the fraction of visible sky corresponding to clouds and to clear sky. The implementation of predictive models in the prototype has been validated and the system is able to function reliably, providing measurements and four-hour forecasts of cloudiness, solar radiation and air temperature

    Less is more: Antibiotics at the beginning of life.

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    Antibiotic exposure at the beginning of life can lead to increased antimicrobial resistance and perturbations of the developing microbiome. Early-life microbiome disruption increases the risks of developing chronic diseases later in life. Fear of missing evolving neonatal sepsis is the key driver for antibiotic overtreatment early in life. Bias (a systemic deviation towards overtreatment) and noise (a random scatter) affect the decision-making process. In this perspective, we advocate for a factual approach quantifying the burden of treatment in relation to the burden of disease balancing antimicrobial stewardship and effective sepsis management

    Less is more: Antibiotics at the beginning of life

    Get PDF
    Antibiotic exposure at the beginning of life can lead to increased antimicrobial resistance and perturbations of the developing microbiome. Early-life microbiome disruption increases the risks of developing chronic diseases later in life. Fear of missing evolving neonatal sepsis is the key driver for antibiotic overtreatment early in life. Bias (a systemic deviation towards overtreatment) and noise (a random scatter) affect the decision-making process. In this perspective, we advocate for a factual approach quantifying the burden of treatment in relation to the burden of disease balancing antimicrobial stewardship and effective sepsis management

    Phase II TPDCV protocol for pediatric low-grade hypothalamic/chiasmatic gliomas: 15-year update

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    To report long-term results for children with low-grade hypothalamic/chiasmatic gliomas treated on a phase II chemotherapy protocol. Between 1984 and 1992, 33 children with hypothalamic/chiasmatic LGGs received TPDCV chemotherapy on a phase II prospective trial. Median age was 3.0 years (range 0.3–16.2). Twelve patients (36%) underwent STRs, 14 (42%) biopsy only, and seven (21%) no surgery. Twenty patients (61%) had pathologic JPAs, nine (27%) grade II gliomas, and four (12%) no surgical sampling. Median f/u for surviving patients was 15.2 years (range 5.3–20.7); 20 of the 23 surviving patients had 14 or more years of follow-up. Fifteen-year PFS and OS were 23.4 and 71.2%, respectively. Twenty-five patients progressed, of whom 13 are NED, two are AWD, and 10 have died. All children who died were diagnosed and first treated at age three or younger. Age at diagnosis was significantly associated with relapse and survival (P = 0.004 for PFS and P = 0.037 for OS). No PFS or OS benefit was seen with STR versus biopsy/no sampling (P = 0.58 for PFS, P = 0.59 for OS). For patients with JPAs and WHO grade II tumors, the 15-year PFS was 18.8 and 22.2% (P = 0.95) and 15-year OS was 73.7 and 55.6% (P = 0.17), respectively. Upfront TPDCV for children with hypothalamic/chiasmatic LGGs resulted in 15-year OS of 71.2% and 15-year PFS of 23.4%. No survival benefit is demonstrated for greater extent of resection. Age is a significant prognostic factor for progression and survival

    Analysis of Antibiotic Exposure and Early-Onset Neonatal Sepsis in Europe, North America, and Australia.

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    IMPORTANCE Appropriate use of antibiotics is life-saving in neonatal early-onset sepsis (EOS), but overuse of antibiotics is associated with antimicrobial resistance and long-term adverse outcomes. Large international studies quantifying early-life antibiotic exposure along with EOS incidence are needed to provide a basis for future interventions aimed at safely reducing neonatal antibiotic exposure. OBJECTIVE To compare early postnatal exposure to antibiotics, incidence of EOS, and mortality among different networks in high-income countries. DESIGN, SETTING, AND PARTICIPANTS This is a retrospective, cross-sectional study of late-preterm and full-term neonates born between January 1, 2014, and December 31, 2018, in 13 hospital-based or population-based networks from 11 countries in Europe and North America and Australia. The study included all infants born alive at a gestational age greater than or equal to 34 weeks in the participating networks. Data were analyzed from October 2021 to March 2022. EXPOSURES Exposure to antibiotics started in the first postnatal week. MAIN OUTCOMES AND MEASURES The main outcomes were the proportion of late-preterm and full-term neonates receiving intravenous antibiotics, the duration of antibiotic treatment, the incidence of culture-proven EOS, and all-cause and EOS-associated mortality. RESULTS A total of 757 979 late-preterm and full-term neonates were born in the participating networks during the study period; 21 703 neonates (2.86%; 95% CI, 2.83%-2.90%), including 12 886 boys (59.4%) with a median (IQR) gestational age of 39 (36-40) weeks and median (IQR) birth weight of 3250 (2750-3750) g, received intravenous antibiotics during the first postnatal week. The proportion of neonates started on antibiotics ranged from 1.18% to 12.45% among networks. The median (IQR) duration of treatment was 9 (7-14) days for neonates with EOS and 4 (3-6) days for those without EOS. This led to an antibiotic exposure of 135 days per 1000 live births (range across networks, 54-491 days per 1000 live births). The incidence of EOS was 0.49 cases per 1000 live births (range, 0.18-1.45 cases per 1000 live births). EOS-associated mortality was 3.20% (12 of 375 neonates; range, 0.00%-12.00%). For each case of EOS, 58 neonates were started on antibiotics and 273 antibiotic days were administered. CONCLUSIONS AND RELEVANCE The findings of this study suggest that antibiotic exposure during the first postnatal week is disproportionate compared with the burden of EOS and that there are wide (up to 9-fold) variations internationally. This study defined a set of indicators reporting on both dimensions to facilitate benchmarking and future interventions aimed at safely reducing antibiotic exposure in early life
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