23 research outputs found

    The development of an earth resources information system using aerial photographs and digital computers

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    Analytical photogrammetry demonstrated that automatic three dimensional mapping of forest terrain was technically feasible. The examples were black and white photography at scales of 1:10,000 and 1:24,000. The major improvement in terrain modelling was the addition of the capability of joining small quadrangles together to form one large model about equal to the effective area of the pair of photographs. Improvements of somewhat lesser importance include: (1) the use of up to 16 grey levels; (2) the elimination of several coordinate transformations; and (3) the annotation of three-tone hysocline maps with elevations

    The impact of COVID-19 vaccination on California's return to normalcy.

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    SARS-CoV-2 has infected nearly 3.7 million and killed 61,722 Californians, as of May 22, 2021. Non-pharmaceutical interventions have been instrumental in mitigating the spread of the coronavirus. However, as we ease restrictions, widespread implementation of COVID-19 vaccines is essential to prevent its resurgence. In this work, we addressed the adequacy and deficiency of vaccine uptake within California and the possibility and severity of resurgence of COVID-19 as restrictions are lifted given the current vaccination rates. We implemented a real-time Bayesian data assimilation approach to provide projections of incident cases and deaths in California following the reopening of its economy on June 15, 2021. We implemented scenarios that vary vaccine uptake prior to reopening, and transmission rates and effective population sizes following the reopening. For comparison purposes, we adopted a baseline scenario using the current vaccination rates, which projects a total 11,429 cases and 429 deaths in a 15-day period after reopening. We used posterior estimates based on CA historical data to provide realistic model parameters after reopening. When the transmission rate is increased after reopening, we projected an increase in cases by 21.8% and deaths by 4.4% above the baseline after reopening. When the effective population is increased after reopening, we observed an increase in cases by 51.8% and deaths by 12.3% above baseline. A 30% reduction in vaccine uptake alone has the potential to increase cases and deaths by 35% and 21.6%, respectively. Conversely, increasing vaccine uptake by 30% could decrease cases and deaths by 26.1% and 17.9%, respectively. As California unfolds its plan to reopen its economy on June 15, 2021, it is critical that social distancing and public behavior changes continue to be promoted, particularly in communities with low vaccine uptake. The Centers for Disease Control and Prevention (CDC) recommendation to ease mask-wearing for fully vaccinated individuals despite major inequities in vaccine uptake in counties across the state highlights some of the logistical challenges that society faces as we enthusiastically phase out of this pandemic

    Care For The Caregiver: Evaluation of Mind-Body Self-Care for Accelerated Nursing Students

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    Stress affects the well-being of both nursing students and the individuals with whom they work. With the theory of cognitive appraisal as a framework for this study, it is proposed that mind-body self-care strategies promote stress management by stabilization of emotions. Outcomes will be a perception of less stress and more mindful engagement with the environment. Objective of the study was to describe an evaluation of student perceived stress and mindfulness to 1-hour per week of class time dedicated to mind-body self-care (yoga, mindful breathing, Reiki, and essential oil therapy). It was a quasi-experimental study; data collection took place at 4 time points. Participants were entry-level accelerated nursing students from 3 US universities: 50 in the treatment group, 64 in the comparison group. Data included health-promoting practices using Health-Promoting Promotion Lifestyle Profile II as a control variable, stress and mindfulness (Perceived Stress Scale [PSS] and Mindful Attention Awareness Scale [MAAS]), and demographic information; analysis using mixed-design repeated-measures analysis of variances. There was a statistically significant interaction between intervention and time on PSS scores, F(3, 264) = 3.95, P = .009, partial η2 = 0.043, with PSS scores of the intervention group decreasing from baseline to T3 when intervention ended whereas PSS scores of the comparison group increased from baseline. The average scores on the MAAS did not differ significantly. Evaluation of an embedded mind-body self-care module in the first nursing course demonstrated promising improvements in stress management. The findings support the appropriateness of integrating mind-body self-care content into nursing curricula to enhance students\u27 ability to regulate stress

    Care For The Caregiver: Evaluation of Mind-Body Self-Care for Accelerated Nursing Students

    No full text
    Stress affects the well-being of both nursing students and the individuals with whom they work. With the theory of cognitive appraisal as a framework for this study, it is proposed that mind-body self-care strategies promote stress management by stabilization of emotions. Outcomes will be a perception of less stress and more mindful engagement with the environment. Objective of the study was to describe an evaluation of student perceived stress and mindfulness to 1-hour per week of class time dedicated to mind-body self-care (yoga, mindful breathing, Reiki, and essential oil therapy). It was a quasi-experimental study; data collection took place at 4 time points. Participants were entry-level accelerated nursing students from 3 US universities: 50 in the treatment group, 64 in the comparison group. Data included health-promoting practices using Health-Promoting Promotion Lifestyle Profile II as a control variable, stress and mindfulness (Perceived Stress Scale [PSS] and Mindful Attention Awareness Scale [MAAS]), and demographic information; analysis using mixed-design repeated-measures analysis of variances. There was a statistically significant interaction between intervention and time on PSS scores, F(3, 264) = 3.95, P = .009, partial η2 = 0.043, with PSS scores of the intervention group decreasing from baseline to T3 when intervention ended whereas PSS scores of the comparison group increased from baseline. The average scores on the MAAS did not differ significantly. Evaluation of an embedded mind-body self-care module in the first nursing course demonstrated promising improvements in stress management. The findings support the appropriateness of integrating mind-body self-care content into nursing curricula to enhance students\u27 ability to regulate stress

    3D Micromachined Polyimide Mixing Devices for in Situ X-ray Imaging of Solution-Based Block Copolymer Phase Transitions

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    Advances in modern interface- and material sciences often rely on the understanding of a system’s structure–function relationship. Designing reproducible experiments that yield in situ time-resolved structural information at fast time scales is therefore of great interest, e.g., for better understanding the early stages of self-assembly or other phase transitions. However, it can be challenging to accurately control experimental conditions, especially when samples are only available in small amounts, prone to agglomeration, or if X-ray compatibility is required. We address these challenges by presenting a microfluidic chip for triggering dynamics via rapid diffusive mixing for in situ time-resolved X-ray investigations. This polyimide/Kapton-only-based device can be used to study the structural dynamics and phase transitions of a wide range of colloidal and soft matter samples down to millisecond time scales. The novel multiangle laser ablation three-dimensional (3D) microstructuring approach combines, for the first time, the highly desirable characteristics of Kapton (high X-ray stability with low background, organic solvent compatibility) with a 3D flow-focusing geometry that minimizes mixing dispersion and wall agglomeration. As a model system, to demonstrate the performance of these 3D Kapton microfluidic devices, we selected the non-solvent-induced self-assembly of biocompatible and amphiphilic diblock copolymers. We then followed their structural evolution in situ at millisecond time scales using on-the-chip time-resolved small-angle X-ray scattering under continuous-flow conditions. Combined with complementary results from 3D finite-element method computational fluid dynamics simulations, we find that the nonsolvent mixing is mostly complete within a few tens of milliseconds, which triggers initial spherical micelle formation, while structural transitions into micelle lattices and their deswelling only occur on the hundreds of milliseconds to second time scale. These results could have an important implication for the design and formulation of amphiphilic polymer nanoparticles for industrial applications and their use as drug-delivery systems in medicine

    Understanding of casein micelles concentrated layers properties during cross flow ultrafiltration by in-situ small-angle X-ray scattering (SAXS)

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    Ultra- and microfiltration of skim milk are widely used in the dairy industry for concentration and the fractionation of milk proteins. However their performances are limited by formation of a concentrated fouling layer of casein micelles at the membrane surface. Some precedent results on the possibly effect of operatingconditions have been highlighted by Qu et al. (2012) and Jin et al. (2014). Nevertheless, there is a lack of knowledge on the behaviour of concentrated layer (sol-gel transition and reversibility) at different operating conditions. Consequently, the aim of this work is to elucidate the local structure and time dependant organization of casein micelles fouling layer under various operating conditions thanks to in-situsmall-angle X-ray scattering SAXS during cross-flow ultrafiltration. This allowed to (i) distinguish the thickness and local solid concentration profiles in flowing (sol) and stagnant (gel) parts of the fouling layer; (ii) discriminate the effect of time, transmembrane pressure TMP, shear and temperature on the sol-gel transition; (iii) study the reversibility of the sol-gel transition under the moderate laminar cross flow.Material and MethodsDispersion with initial casein micelle concentration of 54.7 g.L-1 (2.1 C0 with C0 = 26 g.L-1) was prepared from casein micelle powder (Promilk 802 B, Ingredia, Arras, France) dispersed in preliminary obtained milk ultrafiltrate (Qu et al., 2012). The dispersions were prepared by thoroughly mixing the casein powder in a UF permeate for 15h at 35°C. SAXS experiments were performed at ID02 High Brilliance beamline of ESRF (Grenoble, France) with the help of specially developed SAXScross-flow ultrafiltration cell (Jin et al., 2014). Polyethersulfone ultrafiltration membrane with nominal MWCO of 100 kDa (Pleiade, Orelis Environnement, France) was used for filtration. Those experiments allowed to access to the structural organization at nanometer length scales and concentration profiles at the vicinity of the membrane surface. The profiles of casein micelles concentration in the fouling layer (local casein concentration versus distance to membrane) were obtained with spatial resolution of 20 μm. The impact of transmembrane pressure (10 and 110 kPa),cross-flow velocity (0.03, 0.05 and 0.15m.s-1) and, notably, temperature (12, 25 and 44°C) on the local structure of fouling layer was studied during different stages of filtration (layer formation → relaxation → erosion). Results and DiscussionFiltration run in figure 1 was carried out at v = 0.03m.s-1 and TMP = 110 kPa. A second step of relaxation wasperformed by reducing the TMP at 10 kPa. Finally, erosion step at 10 kPa and 0.15m.s-1 was applied to try toeliminate the fouling layer. Such conditions allow to build a thick casein micelle layer of around 125 μm (Fig. 1) with a maximal concentration of 7.5 C0 (around 195 g.L-1) close to the membrane (z = 30 μm) above the sol- gel transition (180g/L), according to Bouchoux et al. (2009) and Jin et al. (2014). The SAXS analysis revealed that this highly concentrated layer is mostly reversible since it lasts a 50-70 μm of casein micelles layer reaching 3.5 C0 (around 91 g.L-1) close to the membrane. The effect of temperature on the concentration profile and its reversibility has been studied for three independent filtrations (Fig. 2). Concentrated layer thickness increased with temperature: from ∼100 μm at 12°C to 150 μm at 25°C and 200 μm at 44°C (after 183 ± 9min of filtration) and decreased with shear. However, the concentration distribution profile did not evolve with layer thickness. A maximal concentration is observed for filtration performed at 25°C. Irreversibility is similar for all the temperatures since a 3.5 C0 (around 91 g.L-1) fouling layer close to the membrane is lasting after pressure relaxation.ConclusionIn-situ SAXS measurements during cross-flow ultrafiltration of casein micelles allowed to follow theformation and reversibility of concentration polarization layers as a function of time, TMP, cross-flow andtemperature conditions. It leads to identify sol-gel transition of casein micelles near the membrane surface and to distinguish which part was reversible and eliminated by TMP relaxation. Those results are important for understanding the mechanisms of concentration during cross-flow filtration and they could be used to adjust the filtration parameter
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