Evidence for inertial droplet clustering in weakly turbulent clouds

Simultaneous observations of cloud droplet spatial statistics, cloud droplet size distribution and cloud turbulence were made during several cloud passages, including cumulus clouds and a stratus cloud. They provide evidence that inertial droplet clustering occurs even in weakly turbulent clouds. The measurements were made from the Airborne Cloud Turbulence Observation System suspended from a tethered balloon. For a profile through a stratus cloud with gradually changing droplet Stokes number, droplet clustering, quantified by the pair correlation function, is observed to be positively correlated with the droplet Stokes number. This implies that the droplet collision rate, which is relevant to drizzle formation via droplet coalescence, depends not only on the droplet size distribution, but also on the cloud turbulence. For cumulus clouds, the relation between droplet clustering and Stokes number seems more complicated. Stokes number is determined by measuring droplet size and local energy dissipation rate, the latter requiring highresolution air velocity measurements not possible on fast-flying aircraft

Vertical aerosol particle exchange in the marine boundary layer estimated from helicopter-borne measurements in the Azores region

Aerosol particles are important for radiation effects, cloud formation, and therefore the climate system. A detailed understanding of the spatial distribution of aerosol particles within the atmospheric boundary layer, which depends on sources and sinks, as well as long-range transport and vertical exchange, is important. Especially in marine regions, where the climate effect of clouds is comparably high, long-range transport with subsequent vertical mixing dominates over local aerosol sources. In this study, three different methods were applied to estimate the vertical aerosol particle flux in the marine boundary layer (MBL) and the vertical exchange between the MBL and the free troposphere (FT): eddy covariance (EC), flux–gradient similarity (K theory), and the mixed-layer gradient method (MLG). For the first time, MBL aerosol fluxes derived from these three methods were compared in the framework of the “Azores Stratocumulus Measurements of Radiation, Turbulence and Aerosols” (ACORES) field campaign in the Azores region in the northeastern Atlantic Ocean in July 2017. Meteorological parameters and aerosol and cloud properties were measured in the marine troposphere using the helicopter-borne measurement platform ACTOS (Airborne Cloud Turbulence Observation System). All three methods were applied to estimate the net particle exchange between MBL and FT. In many cases, the entrainment fluxes of the MLG method agreed within the range of uncertainty with the EC and K-theory flux estimates close to the top of the MBL, while the surface flux estimates of the different methods diverged. It was not possible to measure directly above the surface with the helicopter-borne payload, which might be a source of uncertainty in the surface fluxes. The observed particle fluxes at the top of the MBL ranged from 0 to 10×106 m−2 s−1 both in the upward and the downward direction, and the associated uncertainties were on the same order of magnitude. Even though the uncertainties of all three methods are considerable, the results of this study contribute to an improved understanding of the transport of particles between the MBL and FT and their distribution in the MBL

CAMP: An instrumented platform for balloon-borne aerosol particle studies in the lower atmosphere

Airborne observations of vertical aerosol particle distributions are crucial for detailed process studies and model improvements. Tethered balloon systems represent a less expensive alternative to aircraft to probe shallow atmospheric boundary layers (ABLs). This study presents the newly developed cubic aerosol measurement platform (CAMP) for balloon-borne observations of aerosol particle microphysical properties. With an edge length of 35 cm and a weight of 9 kg, the cube is an environmentally robust instrument platform intended for measurements at low temperatures, with a particular focus on applications in cloudy Arctic ABLs. The aerosol instrumentation on board CAMP comprises two condensation particle counters with different lower detection limits, one optical particle size spectrometer, and a miniaturized absorption photometer. Comprehensive calibrations and characterizations of the instruments were performed in laboratory experiments. The first field study with a tethered balloon system took place at the Leibniz Institute for Tropospheric Research (TROPOS) station in Melpitz, Germany, in the winter of 2019. At ambient temperatures between-8 and 15 C, the platform was operated up to a 1.5 km height on 14 flights under both clear-sky and cloudy conditions. The continuous aerosol observations at the ground station served as a reference for evaluating the CAMP measurements. Exemplary profiles are discussed to elucidate the performance of the system and possible process studies. Based on the laboratory instrument characterizations and the observations during the field campaign, CAMP demonstrated the capability to provide comprehensive aerosol particle measurements in cold and cloudy ABLs

Case study of a humidity layer above Arctic stratocumulus and potential turbulent coupling with the cloud top

Specific humidity inversions (SHIs) above low-level cloud layers have been frequently observed in the Arctic. The formation of these SHIs is usually associated with large-scale advection of humid air masses. However, the potential coupling of SHIs with cloud layers by turbulent processes is not fully understood. In this study, we analyze a 3 d period of a persistent layer of increased specific humidity above a stratocumulus cloud observed during an Arctic field campaign in June 2017. The tethered balloon system BELUGA (Balloon-bornE moduLar Utility for profilinG the lower Atmosphere) recorded vertical profile data of meteorological, turbulence, and radiation parameters in the atmospheric boundary layer. An in-depth discussion of the problems associated with humidity measurements in cloudy environments leads to the conclusion that the observed SHIs do not result from measurement artifacts. We analyze two different scenarios for the SHI in relation to the cloud top capped by a temperature inversion: (i) the SHI coincides with the cloud top, and (ii) the SHI is vertically separated from the lowered cloud top. In the first case, the SHI and the cloud layer are coupled by turbulence that extends over the cloud top and connects the two layers by turbulent mixing. Several profiles reveal downward virtual sensible and latent heat fluxes at the cloud top, indicating entrainment of humid air supplied by the SHI into the cloud layer. For the second case, a downward moisture transport at the base of the SHI and an upward moisture flux at the cloud top is observed. Therefore, the area between the cloud top and SHI is supplied with moisture from both sides. Finally, large-eddy simulations (LESs) complement the observations by modeling a case of the first scenario. The simulations reproduce the observed downward turbulent fluxes of heat and moisture at the cloud top. The LES realizations suggest that in the presence of a SHI, the cloud layer remains thicker and the temperature inversion height is elevated

Individual health services

Background: The German statutory health insurance (GKV) reimburses all health care services that are deemed sufficient, appropriate, and efficient. According to the German Medical Association (BÄK), individual health services (IGeL) are services that are not under liability of the GKV, medically necessary or recommendable or at least justifiable. They have to be explicitly requested by the patient and have to be paid out of pocket. Research questions: The following questions regarding IGeL in the outpatient health care of GKV insurants are addressed in the present report: What is the empirical evidence regarding offers, utilization, practice, acceptance, and the relation between physician and patient, as well as the economic relevance of IGeL? What ethical, social, and legal aspects are related to IGeL? For two of the most common IGeL, the screening for glaucoma and the screening for ovarian and endometrial cancer by vaginal ultrasound (VUS), the following questions are addressed: What is the evidence for the clinical effectiveness? Are there sub-populations for whom screening might be beneficial? Methods: The evaluation is divided into two parts. For the first part a systematic literature review of primary studies and publications concerning ethical, social and legal aspects is performed. In the second part, rapid assessments of the clinical effectiveness for the two examples, glaucoma and VUS screening, are prepared. Therefore, in a first step, HTA-reports and systematic reviews are searched, followed by a search for original studies published after the end of the research period of the most recent HTA-report included. Results: 29 studies were included for the first question. Between 19 and 53% of GKV members receive IGeL offers, of which three-quarters are realised. 16 to 19% of the insurants ask actively for IGeL. Intraocular tension measurement is the most common single IGeL service, accounting for up to 40% of the offers. It is followed by ultrasound assessments with up to 25% of the offers. Cancer screening and blood or laboratory services are also frequent and represent a major proportion of the demand. The ethical, social, and legal aspects discussed in the context of IGeL concern eight subject areas: 1. autonomous patient decisions versus obtrusion, 2. commercialization of medicine, 3. duty of patient information, 4. benefit, evidence, and (quality) control, 5. role and relation of physicians and patients, 6. relation to the GKV, 7. social inequality, 8. formally correct performance. For glaucoma screening, no randomized controlled trial (RCT) is identified that shows a patient relevant benefit. For VUS three RCT are included. However, they do not yet present mortality data concerning screened and non-screened persons. VUS screening shows a high degree of over-diagnosis in turn leading to invasive interventions. To diagnose one invasive carcinoma, 30 to 35 surgical procedures are necessary. Conclusion: IGeL are a relevant factor in the German statutory health care system. To provide more transparency, the requests for evidence-based and independent patient information should be considered. Whether official positive and negative-lists could be an appropriate instrument to give guidance to patients and physicians, should be examined. Generally, IGeL must be seen in the broader context of the discussions about the future design and development of the German health care system

Chemotherapeutics Used for High-Risk Neuroblastoma Therapy Improve the Efficacy of Anti-GD2 Antibody Dinutuximab Beta in Preclinical Spheroid Models

Anti-disialoganglioside GD2 antibody ch14.18/CHO (dinutuximab beta, DB) improved the outcome of patients with high-risk neuroblastoma (HR-NB) in the maintenance phase. We investigated chemotherapeutic compounds used in newly diagnosed patients in combination with DB. Vincristine, etoposide, carboplatin, cisplatin, and cyclophosphamide, as well as DB, were used at concentrations achieved in pediatric clinical trials. The effects on stress ligand and checkpoint expression by neuroblastoma cells and on activation receptors of NK cells were determined by using flow cytometry. NK-cell activity was measured with a CD107a/IFN-γ assay. Long-term cytotoxicity was analyzed in three spheroid models derived from GD2-positive neuroblastoma cell lines (LAN-1, CHLA 20, and CHLA 136) expressing a fluorescent near-infrared protein. Chemotherapeutics combined with DB in the presence of immune cells improved cytotoxic efficacy up to 17-fold compared to in the controls, and the effect was GD2-specific. The activating stress and inhibitory checkpoint ligands on neuroblastoma cells were upregulated by the chemotherapeutics up to 9- and 5-fold, respectively, and activation receptors on NK cells were not affected. The CD107a/IFN-γ assay revealed no additional activation of NK cells by the chemotherapeutics. The synergistic effect of DB with chemotherapeutics seems primarily attributed to the combined toxicity of antibody-dependent cellular cytotoxicity and chemotherapy, which supports further clinical evaluation in frontline induction therapy

Chemotherapeutics Used for High-Risk Neuroblastoma Therapy Improve the Efficacy of Anti-GD2 Antibody Dinutuximab Beta in Preclinical Spheroid Models

Anti-disialoganglioside GD2 antibody ch14.18/CHO (dinutuximab beta, DB) improved the outcome of patients with high-risk neuroblastoma (HR-NB) in the maintenance phase. We investigated chemotherapeutic compounds used in newly diagnosed patients in combination with DB. Vincristine, etoposide, carboplatin, cisplatin, and cyclophosphamide, as well as DB, were used at concentrations achieved in pediatric clinical trials. The effects on stress ligand and checkpoint expression by neuroblastoma cells and on activation receptors of NK cells were determined by using flow cytometry. NK-cell activity was measured with a CD107a/IFN-γ assay. Long-term cytotoxicity was analyzed in three spheroid models derived from GD2-positive neuroblastoma cell lines (LAN-1, CHLA 20, and CHLA 136) expressing a fluorescent near-infrared protein. Chemotherapeutics combined with DB in the presence of immune cells improved cytotoxic efficacy up to 17-fold compared to in the controls, and the effect was GD2-specific. The activating stress and inhibitory checkpoint ligands on neuroblastoma cells were upregulated by the chemotherapeutics up to 9- and 5-fold, respectively, and activation receptors on NK cells were not affected. The CD107a/IFN-γ assay revealed no additional activation of NK cells by the chemotherapeutics. The synergistic effect of DB with chemotherapeutics seems primarily attributed to the combined toxicity of antibody-dependent cellular cytotoxicity and chemotherapy, which supports further clinical evaluation in frontline induction therapy

Presentation and medical management of peripheral arterial disease in general practice: rationale, aims, design and baseline results of the PACE-PAD Study

Background: Peripheral arterial disease (PAD) is highly prevalent among individuals of higher age or those with one or more cardiovascular risk factors. Screening for PAD is recommended, since it is often linked to atherothrombotic manifestations in the coronary or carotid circulation and associated with a substantial increase in all-cause and cardiovascular mortality. We aimed to assess patients with newly diagnosed, suspected and confirmed PAD in the primary care setting with regards to clinical characteristics, diagnostic and therapeutic management (including referral to specialists), and medium-term outcomes. Methods: This was a multicentre, prospective, observational cohort study with a cross-sectional and a longitudinal part. A total of 2,781 general practitioners across Germany were cluster randomised to document five consecutive patients each in one of the strata: (1) patients with intermittent claudication (IC) or other typical PAD-related complaints (group A) or (2) patients >55 years of age with one or more risk factors (group B) for PAD (current smoking, diabetes, previous myocardial infection and/or previous stroke). Patients with confirmed PAD will be followed up for diagnostic procedures, therapy and vascular events over 18 months. Results: In group A, a total of 2,131 patients with suspected PAD (80.1% confirmed, 75.9% with referral to specialists) and in group B 9,921 patients were included (44.6% confirmed, 54.6% referral). The ankle-brachial index was calculated in 41.3% and 33.5% only. Mean age was 66.6 years (group A) and 68.4 years (group B), respectively. Vascular risk factors were prevalent in both groups, in particular smoking (group A 44.6%, group B 44.4%), hypertension (73.2 and 78.1%), hypercholesterolaemia (64.6 and 70.6%) and diabetes mellitus (41.7 and 60.6%). Concomitant atherothrombotic morbidities were frequent in both groups. In patients with the respective diseases, antihypertensive, antidiabetic, lipid-lowering and antithrombotic therapies were prescribed in group A in 96.6, 96.0, 91.1 and 89.7% and in group B in 98.3, 97.4, 94.1 and 91.2%. Conclusion: The cross-sectional part of the study indicates a substantial burden of disease in PAD patients in primary care. Treatment rates appear to have improved compared to earlier surveys. In the follow-up period, outcomes of these patients and their association with disease stages, guideline-oriented treatment or patient compliance and disease-coping strategies, among other factors, will be determined