This review paper summarizes current knowledge available for aviation operations related to meteorology and provides suggestions for necessary improvements in the measurement and prediction of ...weather-related parameters, new physical methods for numerical weather predictions (NWP), and next-generation integrated systems. Severe weather can disrupt aviation operations on the ground or in-flight. The most important parameters related to aviation meteorology are wind and turbulence, fog visibility, aerosol/ash loading, ceiling, rain and snow amount and rates, icing, ice microphysical parameters, convection and precipitation intensity, microbursts, hail, and lightning. Measurements of these parameters are functions of sensor response times and measurement thresholds in extreme weather conditions. In addition to these, airport environments can also play an important role leading to intensification of extreme weather conditions or high impact weather events, e.g., anthropogenic ice fog. To observe meteorological parameters, new remote sensing platforms, namely wind LIDAR, sodars, radars, and geostationary satellites, and in situ instruments at the surface and in the atmosphere, as well as aircraft and Unmanned Aerial Vehicles mounted sensors, are becoming more common. At smaller time and space scales (e.g., < 1 km), meteorological forecasts from NWP models need to be continuously improved for accurate physical parameterizations. Aviation weather forecasts also need to be developed to provide detailed information that represents both deterministic and statistical approaches. In this review, we present available resources and issues for aviation meteorology and evaluate them for required improvements related to measurements, nowcasting, forecasting, and climate change, and emphasize future challenges.
This study investigates the effects of aerosols on tropical deep convective clouds (DCCs). A series of large-scale, two-dimensional cloud-resolving model simulations was completed, differing only in ...the concentration of aerosols available to act as cloud condensation nuclei (CCN). Polluted simulations contained more DCCs, wider storms, higher cloud tops, and more convective precipitation domainwide. Differences in warm cloud microphysics were largely consistent with the first and second aerosol indirect effects. The average surface precipitation produced in each DCC column decreased with increasing aerosol concentration. A detailed microphysical budget analysis showed that the reduction in collision and coalescence largely dominated the trend in average precipitation. The production of rain from ice, though it also decreased, became a more important contribution to precipitation as the aerosol concentration increased. The DCCs in polluted simulations contained more frequent extreme values of vertical velocity, but the average updraft speed decreased with increasing aerosols in DCCs above 6 km. An examination of the buoyancy term of the vertical velocity equation demonstrates that the drag associated with condensate loading is an important factor in determining the average updraft strength. The largest contributions to latent heating in DCCs were cloud nucleation and vapor deposition onto water and ice, but changes in latent heating were, on average, an order of magnitude smaller than those in the condensate loading term. The average updraft speed was largely affected by increased drag from condensate loading in more mature updrafts, while early storm updrafts experienced convective invigoration from increased latent heating.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Aerosols are known to have both direct and indirect effects on clouds through their role as cloud condensation nuclei. This study examines the effects of differing aerosol concentrations on ...convective storms developing under different environments. The Regional Atmospheric Modeling System (RAMS), a cloud-resolving model with sophisticated microphysical and aerosol parameterization schemes, was used to achieve the goals of this study. A sounding that would produce deep convection was chosen and consistently modified to obtain a variety of CAPE values. Additionally, the model was initiated with varying concentrations of aerosols that were available to act as cloud condensation nuclei. Each model run produced long-lived convective storms with similar storm development, but they differed slightly based on the initial conditions. Runs with higher initial CAPE values produced the strongest storms overall, with stronger updrafts and larger amounts of accumulated surface precipitation. Simulations initiated with larger concentrations of aerosols developed similar storm structures but showed some distinctive dynamical and microphysical changes because of aerosol indirect effects. Many of the changes seen because of varying aerosol concentrations were of either the same order or larger magnitude than those brought about by changing the convective environment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The recent successful space-borne demonstration of a miniaturized CubeSat precipitation radar is highlighted. The low cost of such a radar, together with the availability of small satellite, ...platforms to carry it, now make it feasible to consider employing a more distributed approach to observe important atmospheric processes that relate to precipitation. An approach to quantify the transport of water and air by deep convection is described based on a clustering of small radar satellites providing measurements seconds apart. This strategy now adds time as a new dimension for observing such processes. A mission concept, referred to as D-train, comprised of a train of three satellites 30, 90, and 120 s apart is described, and the expected performance of it for providing measures of convective transport is examined based on a large ensemble of simulations of convection with an advanced cloud-resolving model.
Hybrid morphology radio sources (HyMoRS) are a rare type of radio galaxy that display different Fanaroff-Riley classes on opposite sides of their nuclei. To enhance the statistical analysis of ...HyMoRS, we embarked on a large-scale search of these sources within the international citizen science project, Radio Galaxy Zoo (RGZ). Here, we present 25 new candidate hybrid morphology radio galaxies. Our selected candidates are moderate power radio galaxies ( W Hz−1 sr−1) at redshifts . Hosts of nine candidates have spectroscopic observations, of which six are classified as quasars, one as high- and two as low-excitation galaxies. Two candidate HyMoRS are giant ( Mpc) radio galaxies, one resides at the center of a galaxy cluster, and one is hosted by a rare green bean galaxy. Although the origin of the hybrid morphology radio galaxies is still unclear, this type of radio source starts depicting itself as a rather diverse class. We discuss hybrid radio morphology formation in terms of the radio source environment (nurture) and intrinsically occurring phenomena (nature; activity cessation and amplification), showing that these peculiar radio galaxies can be formed by both mechanisms. While high angular resolution follow-up observations are still necessary to confirm our candidates, we demonstrate the efficacy of the RGZ in the pre-selection of these sources from all-sky radio surveys, and report the reliability of citizen scientists in identifying and classifying complex radio sources.
Drugs that target novel surfaces on the androgen receptor (AR) and/or novel AR regulatory mechanisms are promising alternatives for the treatment of castrate-resistant prostate cancer. The 52 kDa ...FK506 binding protein (FKBP52) is an important positive regulator of AR in cellular and whole animal models and represents an attractive target for the treatment of prostate cancer. We used a modified receptor-mediated reporter assay in yeast to screen a diversified natural compound library for inhibitors of FKBP52-enhanced AR function. The lead compound, termed MJC13, inhibits AR function by preventing hormone-dependent dissociation of the Hsp90-FKBP52-AR complex, which results in less hormone-bound receptor in the nucleus. Assays in early and late stage human prostate cancer cells demonstrated that MJC13 inhibits AR-dependent gene expression and androgen-stimulated prostate cancer cell proliferation.
In spite of considerable research into the therapies for glioblastoma multiforme this tumour type remains very difficult to treat. As well as having a tendency to be inherently resistant to ...chemotherapy, glioblastoma multiforme also displays local invasion. Cell line studies have a continued and important role to play in understanding the mechanisms associated with both chemotherapy resistance and invasion. In the current study we have utilized the C6 glioma cell line to investigate the response to long-term, clinically relevant application of topoisomerase I and II inhibitors. Treatment with etoposide resulted in an increase in resistance to this topoisomerase II inhibitor. By contrast, the continuous exposure to a topoisomerase I inhibitor did not result in increased drug resistance, but was associated with a reduction in cell migration. This data supports further investigation of topoisomerase I inhibition as a means to inhibit glioma invasion without the development of parallel chemoresistance.
One of the most frequent refrains heard in the public discourse on intimate partner violence (IPV) is why do they stay? The literature has demonstrated that IPV victims face multiple barriers to ...safely exiting their relationships. Currently, there has been a limited examination of the role social media can play in elucidating the lived experience of IPV. With 25% of the population using Twitter, there are opportunities to examine its utility for deepening understandings of IPV. Using data generated from the #WhyIStayed Twitter campaign, the purpose of this study is to examine Twitter users’ reasons for staying in their abusive relationships. The study sample (n = 3,086) is composed of a random sample of 61,725 English speaking tweets globally that employed the #WhyIStayed and #WhyILeft hashtags. We analyzed all tweets using thematic content analysis methods. This process involved multiple rounds of coding. In response to #WhyIStayed, Tweeters worldwide shared the barriers they faced that made leaving their abusive partners difficult. Seven primary themes emerged that influenced their decision-making processes: (a) impact of IPV on personal well-being, (b) lack of awareness regarding the dynamics of abusive relationships, (c) not identifying as a stereotypical IPV victim, (d) fear of reinforcing racial stereotypes, (e) internalizing social scripts regarding relationships, (f) structural barriers, and (g) leaving takes time. Twitter messages have the capacity to function as micronarratives that recount the complex barriers IPV victims confront when negotiating their relationships. This analysis provides a multifaceted description of the challenges associated with leaving abusive relationships that can augment existing theoretical frameworks on victim readiness. Furthermore, these findings demonstrate the myriad ways that societal representations of domestic violence (DV) serve as impediments for victims leaving their abusive relationships. Therefore, social media has the potential to provide a platform for capturing the lived experience of IPV.
Highlights ► FKBP52 is a specific positive regulator of AR, GR and PR signaling pathways. ► FKBP52 is important for mouse reproductive development and gluconeogenesis. ► FKBP52 regulates receptor ...nuclear localization and has proposed roles in the nucleus. ► The FKBP52 proline-rich loop is a functionally important interaction surface. ► Efforts to target FKBP52 for treatment of hormone-dependent diseases are underway.
Despite the promise of digital technologies to strengthen social work practice, like many other social service organizations, service providers at domestic violence (DV) and sexual assault (SA) ...organizations have yet to fully embrace their use in their work. Our study explores teen dating violence (TDV) service providers' perceptions of both the benefits and the risks of using digital technologies in their service delivery system. We conducted in-depth qualitative interviews with TDV staff at agencies throughout the United States (N = 35). Findings suggest service providers are actively negotiating the ways technology can nurture their clients' safety or perpetuate harm including exacerbating the digital divide. DV service providers contend that while technology can be lifesaving, important considerations must address associated harms.
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