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This article describes a novel approach to nursing education, designed to improve the experience of both students in public health nursing, and the local public health unit where they affiliate. Students, faculty, and public health department staff developed a method for matching programs and needs of the local public health unit to the skills and learning needs of nursing students. We describe our experience articulating student competencies, program-specific functions, and an approach to matching student interests and learning opportunities to agency needs. Students, faculty, and staff rated the program moderately to very high in feasibility, satisfaction, and acceptability. Data suggest the novel program served to improve the quality of the practicum affiliation, to the satisfaction of both the school and agency, while contributing to a robust public health learning experience for emerging professional nurses.

We aim to evaluate the diagnostic value and time course response of the triple inflammatory markers: white blood cell count (WBC), neutrophil percentage (Neu), and C-reactive protein (CRP) in pediatric acute appendicitis. A retrospective review of clinical data pertaining to 1391 patients admitted with suspicion for pediatric appendicitis from 2012 to 2017 was conducted. Triple inflammatory markers were acquired upon admission. Appendicitis was confirmed histologically post-appendectomy. The diagnostic value and time course response of these markers was trended in relation to the duration of abdominal pain on admission. 718 patients had histologically confirmed appendicitis. WBC and Neu demonstrate high sensitivity for early appendicitis at 94.6% and 80.0% at Day 1, while CRP demonstrates highest sensitivity of 97.9% at Day 4. The triple markers had poor overall diagnostic value when interpreted individually, however, had a high combined sensitivity of 99.7% and negative predictive value of 98.7% regardless of duration of disease. Overall negative appendectomy rate was 6.7% (n = 52). Among 19 patients with triple markers negative who underwent appendectomy, 17 (89.5%) were histologically normal. The triple inflammatory markers have limited diagnostic value when interpreted individually, but are strong discriminators of pediatric appendicitis when combined. Their high sensitivity and negative predictive value could potentially help patients avoid unnecessary admissions or costly imaging studies, and reduce negative appendectomy rates. In addition, their objective nature confers an advantage over existing clinical scoring systems which comprise subjective elements.

Cirrus clouds and their effects on earth’s radiative balance are major sources of uncertainties in predicting future climate. These clouds also dehydrate air ascending to the tropopause, thereby reducing water content in the stratosphere. However, the formation of cirrus clouds is not well understood. Data from field sites and campaigns have shown that organic aerosols (OAs) is a major component of the non-refractory aerosols in the free troposphere where ice cirrus clouds typically form. Measurements by aerosol mass spectrometers in the free troposphere above forests indicate a high mass fraction of these OAs are derived from the atmospheric oxidation of isoprene and other volatile organic compounds (VOCs). Despite their abundance, the effects of these OAs on ice nucleation (IN) is controversial. Previously, these OAs were assumed to be homogeneously mixed liquids, which limits their INabilities. Recent studies have shown that depending on the ambient humidity and temperature, OAs can exist in semi-solid or solid phase states, which can potentially increase INactivity. This laboratory study systematically examines the effects of aerosol-phase state on IN properties of secondary organic aerosols (SOA) produced by the environmental chamber by simultaneously measuring their chemical composition and ice nucleation properties. Selected types of SOA particles were generated by reacting the respective volatile organic compounds (VOCs) with either ozone and/or OH radicals in the MIT environmental chamber and a potential aerosol mass (PAM) oxidation flow reactor. Four kinds of SOA, namely a-pinene SOA, toluene SOA, -caryophyllene SOA, and IEPOX-derived SOA were generated and passed through a temperature control apparatus, where the temperature of the aerosols can be varied between -42°C and 20°C before entering the spectrometer for ice nucleation (SPIN, Droplet Measurement Technologies, Inc.) for determining ice nucleation activity. A scanning mobility particle sizer (SMPS) and an aerosol mass spectrometer (AMS, Aerodyne Inc.) measured the number-diameter distribution and chemical composition of the particles upstream of the SPIN. An optical particle counter downstream of the SPIN measured the optical signatures of the ice particles and some of the large bare organic particles. The SPIN operating temperature was between -38°C and -46°C. Our results show that pre-cooling the aerosol particles to -25 to -42°C enhances the IN onset relative humidity (RH) and the active fraction of IN when compared with non-pre-cooling conditions only for -caryophyllene SOA and IEPOX-derived SOA. Coupled with viscosity and glass transition temperature calculations, we show that the aerosol phase state changes due to the pre-cooling explains this enhancement. By combining the ice nucleation results with chemical analysis of the SOA, our study suggests that the chemical composition influences of these organic aerosols alter the hygroscopicity and the phase state of these organic aerosols, which eventually affects their INproperties. As the phase state of the organic aerosols changes from liquid to semi-solid or solid, their INonset relative humidity decreases, suggesting certain types of SOA (including b-caryophyllene and isoprene SOA) could be potentially important ice nuclei in the free troposphere., 100th American Meteorological Society Annual Meeting, 11-16 January, 2020, Boston, MA, USA

Real time and long-term monitoring of aerosol chemical species is the subject of great scientific concerns and numerous technological developments. The Aerodyne Aerosol Chemical Speciation monitor (ACSM) has been developed for this purpose. It is currently operational at over 60 monitoring stations worldwide, with almost half of them being located in Europe (notably within the Aerosols, Clouds, and Trace gases Research InfraStructure). Understanding the reponse of these instruments to different chemical species and quantifying any possible artefacts is essential if we are to use these measurements for comparative studies and for model evaluation and development. A few recent studies have illustrated such possible measurement artefacts, notably at the mz44 peak (Crenn et al, 2015, Frohlich et al, 2015). The related variability in instrument response has been linked to an artefact response to inorganic aerosol (Pieber et al.,2016), however more recent work has illustrated that this response is dependent on aerosol mixing state (Freney et al., 2019). Here, we present results of laboratory experiments where the mz44 artefact was evaluated for various inorganic and organic mixtures, and a co-located measurement campaign in ambient air...

The Aerosol Chemical Speciation Monitor (ACSM, Aerodyne Res. Inc.) has been installed in a growing number of supersites around the world for long-term monitoring of the submicron aerosol chemical composition. In Europe, most of these ACSM measurements are part of the European research infrastructure for aerosol, clouds, and trace gases (ACTRIS, http://www.actris.eu). Coordinated efforts to ensure that measurement are comparable from one site to another, and that all instruments follow recommended standard operating procedures are essential for the data quality of these networks. Within ACTRIS, selected expertise centers offer training and calibration of the instruments used in the network. The Aerosol Chemical Monitor Calibration Centre (ACMCC) is dedicated to online aerosol chemical monitors, with a first ACSM intercomparison/calibration campaign performed in 2013 (Crenn et al, 2014; Frohlich et al., 2014). In 2016, a second large ACTRIS campaign involved 15 quadrupole ACSMs and 6 of the newer ToF-ACSM devices. In this work, we present the results obtained from this 2016 intercomparison, focusing on new calibration procedures and on the influence of artefacts recently identified for aerosol mass spectrometer measurements (Pieber et al., 2016). These new procedures result in a significant improvement in the agreement between the Quad-ACSM instruments (Fig. 1). Results obtained by the 6 ToF-ACSM devices also allow for the first time extensive comparison of these instruments (Fig. 2), showing consistency between them as well as with data measured from the conventional quadrupole ACSM.

Genotype variation in selected Kenyan barley breeding lines was determined by differential profiles of seed hordein proteins using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Consequently, a phylogenetic relationship derived from unweighted pair group method with arithmetic mean Jaccard clustering matrix was generated based on absence or presence of hordein bands. In parallel, physiological and molecular responses to abiotic stresses were evaluated in seedlings. For physiological assays seedlings were exposed to 0, 300, 600 mM NaCl. Variation in physiological parameters including ionic conductance, lipid peroxidation, chlorophyll content, accumulation of proline, glycine betaine, sucrose was determined. Response to abiotic stress was found to be genotype dependent and varied with the stress magnitude. A low ionic conductance, lipid peroxidation and increased proline, sucrose, GB, chlorophyll were associated with stress tolerance. The lines Nguzo, MN-24 and MN-8 were tolerant while Karne, and Sabini were susceptible to abiotic stress. Transcript analysis of selected members of the dehydrin (Dhn) superfamily (LEA II) genes in root and shoot tissue were evaluated. Expression of Dhn genes was found to be genotype dependent, tissue specific and was affected by type and duration of stress. Dehydrin Dhn1 and Dhn9 genes were exclusively dehydration responsive while Dhn3, Dhn4 and Dhn7 were induced by both dehydration and increased salt treatments. Immunoblot analysis using polyclonal anti-sera detecting the K segment consensus peptide TGEKKGIMDKIKEKLPGQH showed a direct correlation between transcript level and accumulation of corresponding Dhn proteins in response to stress. These screening assays may be potential selection markers to aid rapid screening in breeding programs.

Mobile sources produce a significant fraction of the total anthropogenic emissions burden in large cities and have harmful effects on air quality at multiple spatial scales. Mobile emissions are intrinsically difficult to estimate due to the large number of parameters affecting the emissions variability within and across vehicles types. The MCMA-2003 Campaign in Mexico City has showed the utility of using a mobile laboratory to sample and characterize specific classes of motor vehicles to better quantify their emissions characteristics as a function of their driving cycles. The technique clearly identifies "high emitter" vehicles via individual exhaust plumes, and also provides fleet average emission rates. We have applied this technique to Mexicali during the Border Ozone Reduction and Air Quality Improvement Program (BORAQIP) for the Mexicali-Imperial Valley in 2005. We analyze the variability of measured emission ratios for emitted NOx, CO, specific VOCs, NH3, and some primary fine particle components and properties by deploying a mobile laboratory in roadside stationary sampling, chase and fleet average operational sampling modes. The measurements reflect various driving modes characteristic of the urban fleets. The observed variability for all measured gases and particle emission ratios is greater for the chase and roadside stationary sampling than for fleet average measurements. The fleet average sampling mode captured the effects of traffic conditions on the measured on-road emission ratios, allowing the use of fuel-based emission ratios to assess the validity of traditional "bottom-up" emissions inventories. Using the measured on-road emission ratios, we estimate CO and NOx mobile emissions of 175±62 and 10.4±1.3 metric tons/day, respectively, for the gasoline vehicle fleet in Mexicali. Comparisons with similar on-road emissions data from Mexico City indicated that fleet average NO emission ratios were around 20% higher in Mexicali than in Mexico City whereas HCHO and NH3 emission ratios were higher by a factor of 2 in Mexico City than in Mexicali. Acetaldehyde emission ratios did not differ significantly whereas selected aromatics VOCs emissions were similar or smaller in Mexicali. Nitrogen oxides emissions for on-road heavy-duty diesel truck (HDDT) were measured near Austin, Texas, as well as in both Mexican cities, with NOy emission ratios in Austin < Mexico City < Mexicali.

Elemental compositions of organic aerosol (OA) particles provide useful constraints on OA sources, chemical evolution, and effects. The Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) is widely used to measure OA elemental composition. This study evaluates AMS measurements of atomic oxygen-to-carbon (O : C), hydrogen-to-carbon (H : C), and organic mass-to-organic carbon (OM : OC) ratios, and of carbon oxidation state (OSC) for a vastly expanded laboratory data set of multifunctional oxidized OA standards. For the expanded standard data set, the method introduced by Aiken et al. (2008), which uses experimentally measured ion intensities at all ions to determine elemental ratios (referred to here as "Aiken-Explicit"), reproduces known O : C and H : C ratio values within 20% (average absolute value of relative errors) and 12%, respectively. The more commonly used method, which uses empirically estimated H2O+ and CO+ ion intensities to avoid gas phase air interferences at these ions (referred to here as "Aiken-Ambient"), reproduces O : C and H : C of multifunctional oxidized species within 28 and 14% of known values. The values from the latter method are systematically biased low, however, with larger biases observed for alcohols and simple diacids. A detailed examination of the H2O+, CO+, and CO2+ fragments in the high-resolution mass spectra of the standard compounds indicates that the Aiken-Ambient method underestimates the CO+ and especially H2O+ produced from many oxidized species. Combined AMS–vacuum ultraviolet (VUV) ionization measurements indicate that these ions are produced by dehydration and decarboxylation on the AMS vaporizer (usually operated at 600 °C). Thermal decomposition is observed to be efficient at vaporizer temperatures down to 200 °C. These results are used together to develop an "Improved-Ambient" elemental analysis method for AMS spectra measured in air. The Improved-Ambient method uses specific ion fragments as markers to correct for molecular functionality-dependent systematic biases and reproduces known O : C (H : C) ratios of individual oxidized standards within 28% (13%) of the known molecular values. The error in Improved-Ambient O : C (H : C) values is smaller for theoretical standard mixtures of the oxidized organic standards, which are more representative of the complex mix of species present in ambient OA. For ambient OA, the Improved-Ambient method produces O : C (H : C) values that are 27% (11%) larger than previously published Aiken-Ambient values; a corresponding increase of 9% is observed for OM : OC values. These results imply that ambient OA has a higher relative oxygen content than previously estimated. The OSC values calculated for ambient OA by the two methods agree well, however (average relative difference of 0.06 OSC units). This indicates that OSC is a more robust metric of oxidation than O : C, likely since OSC is not affected by hydration or dehydration, either in the atmosphere or during analysis.

DAURE (Determination of the Sources of Atmospheric Aerosols in Urban and Rural Environments in the Western Mediterranean) was a multidisciplinary international field campaign aimed at investigating the sources and meteorological controls of particulate matter in the Western Mediterranean Basin (WMB). Measurements were simultaneously performed at an urban-coastal (Barcelona, BCN) and a rural-elevated (Montseny, MSY) site pair in NE Spain during winter and summer. State-of-the-art methods such as 14C analysis, proton-transfer reaction mass spectrometry, and high-resolution aerosol mass spectrometry were applied for the first time in the WMB as part of DAURE. WMB regional pollution episodes were associated with high concentrations of inorganic and organic species formed during the transport to inland areas and built up at regional scales. Winter pollutants accumulation depended on the degree of regional stagnation of an air mass under anticyclonic conditions and the planetary boundary layer height. In summer, regional recirculation and biogenic secondary organic aerosols (SOA) formation mainly determined the regional pollutant concentrations. The contribution from fossil sources to organic carbon (OC) and elemental carbon (EC) and hydrocarbon-like organic aerosol concentrations were higher at BCN compared with MSY due to traffic emissions. The relative contribution of nonfossil OC was higher at MSY especially in summer due to biogenic emissions. The fossil OC/EC ratio at MSY was twice the corresponding ratio at BCN indicating that a substantial fraction of fossil OC was due to fossil SOA. In winter, BCN cooking emissions were identified as an important source of modern carbon in primary organic aerosol.

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