Direct Atmospheric Evidence for the Irreversible Formation Of Aqueous Secondary Organic Aerosol

The reversible nature of aqueous secondary organic aerosol (aqSOA) formation was characterized for the first time through direct atmospheric measurements. Water-soluble organic carbon in the gas and particle phases (WSOCg and WSOCp) was measured simultaneously to quantify aqSOA formation in Baltimore, Maryland. During the nighttime, aqSOA formation was evident as WSOCg increasingly partitioned to the particle phase with increasing relative humidity (RH). To characterize the reversible/irreversible nature of this aqSOA, the WSOCp measurement was alternated through an unperturbed ambient channel and through a “dried” channel maintained at ~40% RH (with 7 s residence time) to mimic the natural drying particles undergo throughout the day. Across the entire RH range encountered, there was no statistically significant difference in WSOCp concentrations through the dry and ambient channels, indicating that the aqSOA remained in the condensed phase upon the evaporation of aerosol water. This strongly suggests that the observed aqSOA was formed irreversibly

Honeypot Allocation for Cyber Deception in Dynamic Tactical Networks: A Game Theoretic Approach

Honeypots play a crucial role in implementing various cyber deception techniques as they possess the capability to divert attackers away from valuable assets. Careful strategic placement of honeypots in networks should consider not only network aspects but also attackers' preferences. The allocation of honeypots in tactical networks under network mobility is of great interest. To achieve this objective, we present a game-theoretic approach that generates optimal honeypot allocation strategies within an attack/defense scenario. Our proposed approach takes into consideration the changes in network connectivity. In particular, we introduce a two-player dynamic game model that explicitly incorporates the future state evolution resulting from changes in network connectivity. The defender's objective is twofold: to maximize the likelihood of the attacker hitting a honeypot and to minimize the cost associated with deception and reconfiguration due to changes in network topology. We present an iterative algorithm to find Nash equilibrium strategies and analyze the scalability of the algorithm. Finally, we validate our approach and present numerical results based on simulations, demonstrating that our game model successfully enhances network security. Additionally, we have proposed additional enhancements to improve the scalability of the proposed approach.Comment: This paper accepted in 14th International Conference on Decision and Game Theory for Security, GameSec 202

The Effects of Isoprene and NOx on Secondary Organic Aerosols Formed Through Reversible and Irreversible Uptake to Aerosol Water

Isoprene oxidation produces water-soluble organic gases capable of partitioning to aerosol liquid water. The formation of secondary organic aerosols through such aqueous pathways (aqSOA) can take place either reversibly or irreversibly; however, the split between these fractions in the atmosphere is highly uncertain. The aim of this study was to characterize the reversibility of aqSOA formed from isoprene at a location in the eastern United States under substantial influence from both anthropogenic and biogenic emissions. The reversible and irreversible uptake of water-soluble organic gases to aerosol water was characterized in Baltimore, Maryland, USA, using measurements of particulate water-soluble organic carbon (WSOCp) in alternating dry and ambient configurations. WSOCp evaporation with drying was observed systematically throughout the late spring and summer, indicating reversible aqSOA formation during these times. We show through time lag analyses that WSOCp concentrations, including the WSOCp that evaporates with drying, peak 6 to 11 h after isoprene concentrations, with maxima at a time lag of 9 h. The absolute reversible aqSOA concentrations, as well as the relative amount of reversible aqSOA, increased with decreasing NOx / isoprene ratios, suggesting that isoprene epoxydiol (IEPOX) or other low-NOx oxidation products may be responsible for these effects. The observed relationships with NOx and isoprene suggest that this process occurs widely in the atmosphere, and is likely more important in other locations characterized by higher isoprene and/or lower NOx levels. This work underscores the importance of accounting for both reversible and irreversible uptake of isoprene oxidation products to aqueous particles

Cost-effectiveness of malaria diagnosis using rapid diagnostic tests compared to microscopy or clinical symptoms alone in Afghanistan

Background Improving access to parasitological diagnosis of malaria is a central strategy for control and elimination of the disease. Malaria rapid diagnostic tests (RDTs) are relatively easy to perform and could be used in primary level clinics to increase coverage of diagnostics and improve treatment of malaria.<p></p> Methods A cost-effectiveness analysis was undertaken of RDT-based diagnosis in public health sector facilities in Afghanistan comparing the societal and health sector costs of RDTs versus microscopy and RDTs versus clinical diagnosis in low and moderate transmission areas. The effect measure was ‘appropriate treatment for malaria’ defined using a reference diagnosis. Effects were obtained from a recent trial of RDTs in 22 public health centres with cost data collected directly from health centres and from patients enrolled in the trial. Decision models were used to compare the cost of RDT diagnosis versus the current diagnostic method in use at the clinic per appropriately treated case (incremental cost-effectiveness ratio, ICER).<p></p> Results RDT diagnosis of Plasmodium vivax and Plasmodium falciparum malaria in patients with uncomplicated febrile illness had higher effectiveness and lower cost compared to microscopy and was cost-effective across the moderate and low transmission settings. RDTs remained cost-effective when microscopy was used for other clinical purposes. In the low transmission setting, RDTs were much more effective than clinical diagnosis (65.2% (212/325) vs 12.5% (40/321)) but at an additional cost (ICER) of US$4.5 per appropriately treated patient including a health sector cost (ICER) of US$2.5 and household cost of US$2.0. Sensitivity analysis, which varied drug costs, indicated that RDTs would remain cost-effective if artemisinin combination therapy was used for treating both P. vivax and P. falciparum. Cost-effectiveness of microscopy relative to RDT is further reduced if the former is used exclusively for malaria diagnosis. In the health service setting of Afghanistan, RDTs are a cost-effective intervention compared to microscopy.<p></p> Conclusions RDTs remain cost-effective across a range of drug costs and if microscopy is used for a range of diagnostic services. RDTs have significant advantages over clinical diagnosis with minor increases in the cost of service provision.<p></p&gt

Sociodemographic correlates of cervical cancer screening rates in Calgary, AB: Matched Trend analysis of 2006, 2011 and 2016

Introduction Cervical Cancer Screening (CCS) has reduced the incidence and mortality rates of cervical cancer (CC). However, the benefits are distributed unevenly since 30% of eligible women have not been screened within three years in Alberta. Women who have never been screened or are screened irregularly are most at risk for CC. Objectives and Approach The aim of this study was to understand who gets CCS and who does not, in Calgary, Alberta and analyze the CC policy implications since 2006-2016. CCS information of women aged 25-69 were obtained from Calgary Laboratory Services for the years 2006, 2011 and 2016 and matched with Canadian Census data. Negative binomial regression and Generalized Estimating Equations were used to test associations of CCS rates with socio-demographic variables for eligible women. CCS spatial trends over the years was studied using the GIS Hotspot analysis. Results Major age and geographical variations were observed in CCS rates in Calgary. CCS rates in the recommended age groups varied from 40.6 % to 23.6 %. For age groups between 25 and 54, CCS rates were above 33\%, which implies that many women are having tests more than once every three years. Use was positively associated with median household income, education, Chinese ethnicity and negatively associated with ‘Black’ visible minority status. Women living in lower socio-economic areas of Calgary are screened at lower rates. Hotspot analysis maps revealed heterogeneous testing patterns in the city with relatively higher testing in the downtown, Southeast and Northwest quadrants of the city and relatively decreased CCS in the Northeast quadrant of Calgary Conclusion/Implications Screening programs need to be strengthened with greater focus on including specific demographic groups and reducing overuse. Understanding current testing patterns are important in assessing the benefit to harm ratio of CCS and for monitoring and evaluation of CCS program

Does the family physicians’ characteristics affect Cervical Cancer Screening rates?

Introduction While the effectiveness of cervical cancer-screening (CCS) programs is well accepted, concern is growing regarding Family physicians (FP) poor adherence to CCS guidelines resulting in over and under screening. In Canada, it is a FP responsibility to ensure that the CCS is done as per guidelines and with appropriate follow-up. Objectives and Approach To identify primary care physicians’ characteristics that are associated with over and under CCS for eligible women in Calgary, Alberta. We accessed the Calgary Laboratory Services data for 1475 FPs practicing in Calgary and linked it with the Physicians database of College of Physicians and Surgeons Alberta database. We then matched FP’s gender, country and year of medical school graduation, years since medical school graduation, certification in family medicine and their clinic address with their CCS testing patterns. Using doctors as their own controls, we compared data from 2010-2016 to determine practice variations in CCS patterns subsequent to guideline changes. Results We analyzed approximately 2,400,000 Pap test requisitions (approx. 300,000 per year) to identify screening patterns from 2010-2016 of 1475 family practitioners practicing in Calgary. Our preliminary results identified significant variations in the test ordering patterns of FPs. Approx. half of the male FPs were not performing CCS tests on their eligible female patients. Female FPs ordered more CCS tests than their male counterparts. FP trained in North America, were ordering more pap tests than FPS trained elsewhere. Decreased CSS was also observed among FPs practicing in Northeast Calgary. Conclusion/Implications We detected three CCS patterns: FPs who never perform CSS on eligible female patients; FPs who followed recommended guidelines for performing CCS tests and FPs who performed CCS tests, not following the guidelines. To ensure appropriate use of CSS, identifying intention-behavior relationships and innovative educational interventions for FPs are required

Pyrene coating transition metal disulfides as protection from photooxidation and environmental aging

This article belongs to the Section Nanocomposite Materials.Environmental degradation of transition metal disulfides (TMDs) is a key stumbling block in a range of applications. We show that a simple one-pot non-covalent pyrene coating process protects TMDs from both photoinduced oxidation and environmental aging. Pyrene is immobilized non-covalently on the basal plane of exfoliated MoS2 and WS2. The optical properties of TMD/pyrene are assessed via electronic absorption and fluorescence emission spectroscopy. High-resolution scanning transmission electron microscopy coupled with electron energy loss spectroscopy confirms extensive pyrene surface coverage, with density functional theory calculations suggesting a strongly bound stable parallel-stacked pyrene coverage of ~2–3 layers on the TMD surfaces. Raman spectroscopy of exfoliated TMDs while irradiating at 0.9 mW/4 μm2 under ambient conditions shows new and strong Raman bands due to oxidized states of Mo and W. Yet remarkably, under the same exposure conditions TMD/pyrene remain unperturbed. The current findings demonstrate that pyrene physisorbed on MoS2 and WS2 acts as an environmental barrier, preventing oxidative surface reactions in the TMDs catalyzed by moisture, air, and assisted by laser irradiation. Raman spectroscopy confirms that the hybrid materials stored under ambient conditions for two years remained structurally unaltered, corroborating the beneficial role of pyrene for not only hindering oxidation but also inhibiting aging.This research was funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 642742, under the “Graphene Flagship” project grant agreement No 785219 and under the ESTEEM-3 project grant agreement No 823717. This research was also partially funded by the project “Advanced Materials and Devices” (MIS 5002409), which is implemented under the “Action for the Strategic Development on the Research and Technological Sector” funded by the Operational Program “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014–2020) and co-financed by Greece and the European Union (European Regional Development Fund). This work was supported by the COST Action CA15107 MultiComp. This research was also supported by the Spanish Ministerio de Economia y Competitividad (MAT2016-79776-P), from the Government of Aragon and the European Social Fund under the project “Construyendo Europa desde Aragon” 2014–2020 (grant number E13_17R).Peer reviewe

Définir les compétences procédurales essentielles dans la formation médicale canadienne de premier cycle

Introduction: We conducted a national survey to characterize current Canadian procedural skills training in Undergraduate Medical Education (UGME). The goals were to identify the most important procedures students should know upon graduation and assess clinician-educator perceptions regarding implementation of a pre-clerkship procedural program. Methods: We distributed the survey to physician-educators across Canada’s 17 medical schools. Respondents were directed to an individualized survey that collected demographic data, physician-educator responses on essential procedural skills, as well as physician-educator opinions on the value of a pre-clerkship procedural training program. Results: The response rate for this survey was 21% (42 out of 201 distributed surveys were completed). The top 10 most important procedures identified by physician-educators included IV Access, Airway Management, Local anesthesia/field block, Casting, Spontaneous Vaginal Delivery, Testing for STIs, Phlebotomy, Suturing of Lacerations, Nasogastric Tube Insertion, and Venipuncture. Physician-educators supported a pre-clerkship procedural program. Conclusions: Identifying the most crucial procedural skills is the first step in implementing a competency-based procedural skills training program for Canadian medical students. With the list of essential skills, and the support for physician-educators in developing a pre-clerkship procedural skills curriculum, hopefully there can be future development of formalized curricula.Contexte: Nous avons mené un sondage à l’échelle nationale pour caractériser les compétences procédurales canadiennes dans la formation médicale de premier cycle. L’objectif était de reconnaître les plus importantes procédures que les étudiants devaient connaître à la fin de leur formation et d’évaluer les perceptions des cliniciens éducateurs au sujet de la mise en œuvre de leur programme procédural avant les stages. Méthodes : Nous avons distribué le sondage à des médecins éducateurs dans les 17 écoles de médecine du Canada. Les répondants ont été dirigés vers un sondage individualisé qui recueillait les données démographiques, les réponses des médecins éducateurs sur les compétences procédurales essentielles, ainsi que les opinions des médecins éducateurs sur la valeur du programme de formation procédurale avant les stages. Résultats : Le taux de réponse à ce sondage a été de 21 % (42 des 201 sondages distribués ont été remplis). Les dix plus importantes procédures recensées par les médecins éducateurs comprenaient l’accès IV, l’assistance respiratoire, le bloc anesthésie locale/champ, le moulage de plâtre, l’accouchement spontané par voie vaginale, les tests d’ITS, la phlébotomie, la suture des lacérations, l’insertion d’une sonde nasogastrique et la ponction veineuse. Les médecins éducateurs soutenaient un programme procédural avant les stages. Conclusions : Établir les compétences procédurales les plus essentielles représente la première étape dans la mise en œuvre d’un programme de formation dans les compétences procédurales fondé sur les compétences pour les étudiants canadiens en médecine. Avec la liste de compétences essentielles et le soutien des médecins éducateurs dans le développement d’un programme de compétences procédurales avant les stages, nous espérons qu’un programme structuré sera élaboré

Mapping Regional Turbulent Heat Fluxes via Assimilation of MODIS Land Surface Temperature Data into an Ensemble Kalman Smoother Framework

Estimation of turbulent heat fluxes via variational data assimilation (VDA) approaches has been the subject of several studies. The VDA approaches need an adjoint model that is difficult to derive. In this study, remotely sensed land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) are assimilated into the heat diffusion equation within an ensemble Kalman smoother (EnKS) approach to estimate turbulent heat fluxes. The EnKS approach is tested in the Heihe River Basin (HRB) in northwest China. The results show that the EnKS approach can estimate turbulent heat fluxes by assimilating low temporal resolution LST data from MODIS. The findings indicate that the EnKS approach performs fairly well in various hydrological and vegetative conditions. The estimated sensible (H) and latent (LE) heat fluxes are compared with the corresponding observations from large aperture scintillometer systems at three sites (namely, Arou, Daman, and Sidaoqiao) in the HRB. The turbulent heat flux estimates from EnKS agree reasonably well with the observations, and are comparable to those of the VDA approach. The EnKS approach also provides statistical information on the H and LE estimates. It is found that the uncertainties of H and LE estimates are higher over wet and/or densely vegetated areas (grassland and forest) compared to the dry and/or slightly vegetated areas (cropland, shrubland, and barren land)

Sequence and the Developmental and Tissue-Specific Regulation of the First Complete Vitellogenin Message From Ticks

The first full-length mRNA for vitellogenin (Vg) from ticks was sequenced. This also represents the first complete sequence of Vg from the Chelicerata and of a heme binding Vg. The Vg cDNA from the American dog tick, Dermacentor variabilis was 5744nt in length (GenBank Accession number AY885250), which coded for a protein of 1843aa with a calculated molecular weight of 208kD. This protein had an 18 aa signal sequence, a single RXXR cleavage signal that would generate two subunits (49.5 and 157K in molecular weight) and lipoprotein N-terminal and carboxy von Willebrand factor type D domains. Tryptic digest MS analysis of vitellin protein confirmed the function of the cDNA as the tick yolk protein. Apparently, vitellin in D. variabilis is oligomeric (possibly dimeric) and is comprised of a mixture of the uncleaved monomer and subunits that were predicted from the single RXXR cleavage signal. The highly conserved GL/ICG motif close to the C-terminus in insect Vg genes was different in the tick Vg message, i.e., GLCS. This variant was also present in a partial sequence of Vg from Boophilus microplus. Phylogenic analysis showed that the full length Vg cDNA from D. variabilis and the partial cDNA from B. microplus were distinct from insects and Crustacea. The Vg message was not found in whole body RNA from unfed or fed males or in unfed and partially fed (virgin) females as determined by Northern blotting. The message was found in replete (mated) pre-ovipositional females, increased to higher levels in ovipositing females and was absent after egg laying was complete. The endocrine regulation of the Vg mRNA is discussed. The tissue sources of the Vg message are both the gut and fat body. Tryptic digest MS fingerprinting suggests that a second Vg mRNA might be present in the American dog tick, which needs further study