295 research outputs found

    Searching for Exoplanets Using a Microresonator Astrocomb

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    Detection of weak radial velocity shifts of host stars induced by orbiting planets is an important technique for discovering and characterizing planets beyond our solar system. Optical frequency combs enable calibration of stellar radial velocity shifts at levels required for detection of Earth analogs. A new chip-based device, the Kerr soliton microcomb, has properties ideal for ubiquitous application outside the lab and even in future space-borne instruments. Moreover, microcomb spectra are ideally suited for astronomical spectrograph calibration and eliminate filtering steps required by conventional mode-locked-laser frequency combs. Here, for the calibration of astronomical spectrographs, we demonstrate an atomic/molecular line-referenced, near-infrared soliton microcomb. Efforts to search for the known exoplanet HD 187123b were conducted at the Keck-II telescope as a first in-the-field demonstration of microcombs

    Ultracold dense gas of deeply bound heteronuclear molecules

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    Recently, the quest for an ultracold and dense ensemble of polar molecules has attracted strong interest. Polar molecules have bright prospects for novel quantum gases with long-range and anisotropic interactions, for quantum information science, and for precision measurements. However, high-density clouds of ultracold polar molecules have so far not been produced. Here, we report a key step towards this goal. Starting from an ultracold dense gas of heteronuclear 40K-87Rb Feshbach molecules with typical binding energies of a few hundred kHz and a negligible dipole moment, we coherently transfer these molecules into a vibrational level of the ground-state molecular potential bound by >10 GHz. We thereby increase the binding energy and the expected dipole moment of the 40K-87Rb molecules by more than four orders of magnitude in a single transfer step. Starting with a single initial state prepared with Feshbach association, we achieve a transfer efficiency of 84%. While dipolar effects are not yet observable, the presented technique can be extended to access much more deeply bound vibrational levels and ultimately those exhibiting a significant dipole moment. The preparation of an ultracold quantum gas of polar molecules might therefore come within experimental reach.Comment: 5 pages, 5 figure

    Bridging ultrahigh-Q devices and photonic circuits

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    Optical microresonators are essential to a broad range of technologies and scientific disciplines. However, many of their applications rely on discrete devices to attain challenging combinations of ultra-low-loss performance (ultrahigh Q) and resonator design requirements. This prevents access to scalable fabrication methods for photonic integration and lithographic feature control. Indeed, finding a microfabrication bridge that connects ultrahigh-Q device functions with photonic circuits is a priority of the microcavity field. Here, an integrated resonator having a record Q factor over 200 million is presented. Its ultra-low-loss and flexible cavity design brings performance to integrated systems that has been the exclusive domain of discrete silica and crystalline microcavity devices. Two distinctly different devices are demonstrated: soliton sources with electronic repetition rates and high-coherence/low-threshold Brillouin lasers. This multi-device capability and performance from a single integrated cavity platform represents a critical advance for future photonic circuits and systems

    Transactional paths between children and parents in pediatric asthma: Associations between family relationships and adaptation

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    Introduction. The particular challenges posed by pediatric asthma may have a negative impact on the adaptation of children and their parents. From a transactional approach it is important to examine how reciprocal links between children and parents contribute to explain their adaptation and under which conditions these associations occur. This cross-sectional study aimed at examining the direct and indirect links between children’s and parents’ perceptions of family relationships and adaptation, separately (within-subjects) and across participants (cross-lagged effects), and the role of asthma severity in moderating these associations. Method. The sample comprised 257 children with asthma, aged between 8 and 18 years-old, and one of their parents. Both family members completed self-reported questionnaires on family relationships (cohesion and expressiveness) and adaptation indicators (quality of life and psychological functioning). Physicians assessed asthma severity. Structural Equation Modeling was used to test within-subjects and cross-lagged paths between children’s and parents’ family relationships and adaptation. Results. The model explained 47% of children’s and 30% of parents’ adaptation: family relationships were positively associated with adaptation, directly for children and parents, and indirectly across family members. Asthma severity moderated the association between family relationships and health-related quality of life for children: stronger associations were observed in the presence of persistent asthma. Conclusion. These results highlight the need of including psychological interventions in pediatric healthcare focused on family relationships as potential targets for improving children’s and parents’ quality of life and psychological functioning, and identified the children with persistent asthma as a group that would most benefit from family-based interventions.This study was supported by the R&D Unit Institute of Cognitive Psychology, Vocational and Social Development of the University of Coimbra (PEst-OE/PSI/UI0192/2011) and by the Portuguese Foundation for Science and Technology (PhD Grant SFRH/BD/69885/2010)

    Why Can't Rodents Vomit? A Comparative Behavioral, Anatomical, and Physiological Study

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    The vomiting (emetic) reflex is documented in numerous mammalian species, including primates and carnivores, yet laboratory rats and mice appear to lack this response. It is unclear whether these rodents do not vomit because of anatomical constraints (e.g., a relatively long abdominal esophagus) or lack of key neural circuits. Moreover, it is unknown whether laboratory rodents are representative of Rodentia with regards to this reflex. Here we conducted behavioral testing of members of all three major groups of Rodentia; mouse-related (rat, mouse, vole, beaver), Ctenohystrica (guinea pig, nutria), and squirrel-related (mountain beaver) species. Prototypical emetic agents, apomorphine (sc), veratrine (sc), and copper sulfate (ig), failed to produce either retching or vomiting in these species (although other behavioral effects, e.g., locomotion, were noted). These rodents also had anatomical constraints, which could limit the efficiency of vomiting should it be attempted, including reduced muscularity of the diaphragm and stomach geometry that is not well structured for moving contents towards the esophagus compared to species that can vomit (cat, ferret, and musk shrew). Lastly, an in situ brainstem preparation was used to make sensitive measures of mouth, esophagus, and shoulder muscular movements, and phrenic nerve activity-key features of emetic episodes. Laboratory mice and rats failed to display any of the common coordinated actions of these indices after typical emetic stimulation (resiniferatoxin and vagal afferent stimulation) compared to musk shrews. Overall the results suggest that the inability to vomit is a general property of Rodentia and that an absent brainstem neurological component is the most likely cause. The implications of these findings for the utility of rodents as models in the area of emesis research are discussed. © 2013 Horn et al

    Position statement for a pragmatic approach to immunotherapeutics in patients with inflammatory skin diseases during the coronavirus disease 2019 pandemic and beyond

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    Coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2, a novel RNA virus that was declared a global pandemic on 11 March 2020. The efficiency of infection with SARS-CoV-2 is reflected by its rapid global spread. The SARS-CoV-2 pandemic has implications for patients with inflammatory skin diseases on systemic immunotherapy who may be at increased risk of infection or more severe infection. This position paper is a focused examination of current evidence considering the mechanisms of action of immunotherapeutic drugs in relation to immune response to SARS-CoV-2. We aim to provide practical guidance for dermatologists managing patients with inflammatory skin conditions on systemic therapies during the current pandemic and beyond. Considering the limited and rapidly evolving evidence, mechanisms of action of therapies, and current knowledge of SARS-CoV-2 infection, we propose that systemic immunotherapy can be continued, with special considerations for at risk patients or those presenting with symptoms

    Findings from the Peutz-Jeghers Syndrome Registry of Uruguay

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    Background: Peutz-Jeghers syndrome (PJS) is characterized by intestinal polyposis, mucocutaneous pigmentation and an increased cancer risk, usually caused by mutations of the STK11 gene. This study collected epidemiological, clinical and genetic data from all Uruguayan PJS patients. Methods: Clinical data were obtained from public and private medical centers and updated annually. Sequencing of the STK11 gene in one member of each family was performed. Results and discussion: 25 cases in 11 unrelated families were registered (15 males, 10 females). The average age of diagnosis and death was 18 and 41 years respectively. All patients had characteristic PJS pigmentation and gastrointestinal polyps. 72% required urgent surgery due to intestinal obstruction. 3 families had multiple cases of seizure disorder, representing 20% of cases. 28% developed cancer and two patients had more than one cancer. An STK11 mutation was found in 8 of the 9 families analyzed. A unique M136K missense mutation was noted in one family. Comparing annual live births and PJS birth records from 1970 to 2009 yielded an incidence of 1 in 155,000. Conclusion: The Uruguayan Registry for Peutz-Jeghers patients showed a high chance of emergent surgery, epilepsy, cancer and shortened life expectancy. The M136K missense mutation is a newly reported STK 11 mutation

    Continued improvement of cardiovascular mortality in Hungary - impact of increased cardio-metabolic prescriptions

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    <p>Abstract</p> <p>Background</p> <p>During the last 35 years the poor ranking of Hungary on the list of life expectancy at birth among European countries, has not changed. In 1970 our lag behind the leading European countries was the smallest. The gap was growing between 1970 and 1993 but from 1994 onwards the life expectancy at birth in Hungary has increased continuously and somewhat faster than in other European countries. The aim of this study was to analyze the association between decreasing cardiovascular mortality rates, as a main cause of death and the increase in cardio-metabolic prescriptions and possible changes in lifestyle behavior.</p> <p>Methods</p> <p>Analyses were conducted on national data concerning cardiovascular mortality and the number of cardio-metabolic drug prescription per capita. The association between yearly rates of cardiovascular events and changes in antihypertensive, antilipidemic and antidiabetic prescription rates was analyzed. The changes in other cardiovascular risk factors, like lifestyle were also considered.</p> <p>Results</p> <p>We observed a remarkable decline of mortality due to stroke and acute myocardial infarction (AMI). The fall was significantly associated with all prescription rates. The proportion of each treatment type responsible for suppression of specific mortality rates is different. All treatment types comparably improved stroke mortality, while antilipidemic therapy improved AMI outcome.</p> <p>Conclusions</p> <p>These results emphasize the importance of a comprehensive strategy that maximizes the population coverage of effective treatments. Hungary appears to be at the beginning of the fourth stage of epidemiologic transition, i.e. it has entered the stage of delayed chronic noninfectious diseases.</p

    Cholesteryl Ester Transfer Protein (CETP) Polymorphisms Affect mRNA Splicing, HDL Levels, and Sex-Dependent Cardiovascular Risk

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    Polymorphisms in and around the Cholesteryl Ester Transfer Protein (CETP) gene have been associated with HDL levels, risk for coronary artery disease (CAD), and response to therapy. The mechanism of action of these polymorphisms has yet to be defined. We used mRNA allelic expression and splice isoform measurements in human liver tissues to identify the genetic variants affecting CETP levels. Allelic CETP mRNA expression ratios in 56 human livers were strongly associated with several variants 2.5–7 kb upstream of the transcription start site (e.g., rs247616 p = 6.4×10−5, allele frequency 33%). In addition, a common alternatively spliced CETP isoform lacking exon 9 (Δ9), has been shown to prevent CETP secretion in a dominant-negative manner. The Δ 9 expression ranged from 10 to 48% of total CETP mRNA in 94 livers. Increased formation of this isoform was exclusively associated with an exon 9 polymorphism rs5883-C>T (p = 6.8×10−10) and intron 8 polymorphism rs9930761-T>C (5.6×10−8) (in high linkage disequilibrium with allele frequencies 6–7%). rs9930761 changes a key splicing branch point nucleotide in intron 8, while rs5883 alters an exonic splicing enhancer sequence in exon 9
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