41 research outputs found

    An operational analysis of Lake Surface Water Temperature

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    Operational analyses of Lake Surface Water Temperature (LSWT) have many potential uses including improvement of numerical weather prediction (NWP) models on regional scales. In November 2011, LSWT was included in the Met Office Operational Sea Surface Temperature and Ice Analysis (OSTIA) product, for 248 lakes globally. The OSTIA analysis procedure, which has been optimised for oceans, has also been used for the lakes in this first version of the product. Infra-red satellite observations of lakes and in situ measurements are assimilated. The satellite observations are based on retrievals optimised for Sea Surface Temperature (SST) which, although they may introduce inaccuracies into the LSWT data, are currently the only near-real-time information available. The LSWT analysis has a global root mean square difference of 1.31 K and a mean difference of 0.65 K (including a cool skin effect of 0.2 K) compared to independent data from the ESA ARC-Lake project for a 3-month period (June to August 2009). It is demonstrated that the OSTIA LSWT is an improvement over the use of climatology to capture the day-to-day variation in global lake surface temperatures

    Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

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    A numerical investigation of wind speed effects on lake-effect storms

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    Observations of lake-effect storms that occur over the Great Lakes region during late autumn and winter indicate a high sensitivity to ambient wind speed and direction. In this paper, a two-dimensional version of the Penn State University/National Center for Atmospheric Research (PSU/NCAR) model is used to investigate the wind speed effects on lake-effect snowstorms that occur over the Great Lakes region.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42510/1/10546_2004_Article_BF00708966.pd

    Impact of solvent type on some selected biological properties of parsley Petroselinum crispum (Mill) leaf extracts

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    Pietruszka zwyczajna (Petroselinum crispum Mill) jest wykorzystywana jako surowiec w przemyśle spożywczym m.in. ze względu na dużą zawartość związków fenolowych. W niniejszej pracy badano wpływ rozpuszczalników na skład oraz wybrane biologiczne właściwości ekstraktów z liści P. crispum. Porównano ekstrakty: wodny (W), etanolowy (ET), glikolowo-wodny (GLW) i glicerolowo-wodny (GCW). Największą zawartość związków fenolowych ogółem oznaczono w ekstraktach GLW (2,63 ± 0,03 mg/g s.m.) i GCW (2,12 ± 0,08 mg/g s.m.), natomiast najwięcej flawonoidów zawierał ekstrakt ET (0,86 ± 0,02 mg/g s.m.). Głównymi związkami fenolowymi ekstraktu wodnego były: epikatechina, katechina i jej pochodne, ekstraktu etanolowego – kwasy fenolowe (np. rozmarynowy), ekstraktu GLW – apigenina, natomiast ekstraktu GCW – daidzeina, naryngenina i pochodne. Oprócz znacznych różnic w składzie ilościowym i jakościowym badanych ekstraktów wykazywały one także zróżnicowaną aktywność przeciwrodnikową. Ekstrakt GCW w największym stopniu neutralizował rodnik DPPH• (IC₅₀ = 6,89 ± 056 μg/ml), natomiast ekstrakt W – kationorodnik ABTS•+ (IC₅₀ = 31,44 ± 4,11 μg/ml). Wszystkie ekstrakty wykazywały porównywalną zdolność do chelatowania jonów Fe²⁺. W badaniu cytotoksyczności ekstraktów w warunkach in vitro w stosunku do ludzkiej linii komórkowej BJ (ATCC CRL-2522) wykazano najwyższą cytotoksyczność ekstraktów ET i W. Cytotoksyczność ekstraktów GLW i GCW była porównywalna z cytotoksycznością samych rozpuszczalników. Dowiedziono wpływu rozpuszczalników na skład, właściwości przeciwutleniające oraz cytotoksyczność ekstraktów z P. crispum, wskazując równocześnie na możliwość zastosowania tych ekstraktów w przemyśle spożywczym.Parsley (Petroselinum crispum Mill) is used as a raw material in the food industry because it has, among other things, a high content of phenolics. Under the research study presented, the impact of solvents on the content and some selected biological properties of P. crispum extracts was studied. The following extracts were compared: aqueous (W), ethanolic (ET), aqueous-glycolic (GLW), and aqueousglycerinic (GCW). The highest concentration of total phenolics was determined in the GLW (2.63 ± 0.03 mg/g sm) and GCW (2.12 ± 0.08 mg/g sm) extracts, while the ET extract contained the highest amount of flavonoids (0.86 ± 0.02 mg/g sm). In the W extract, epicatechin, catechin and its derivates were the main phenolic compounds, in the ET extract: phenolic acids (e.g. rosmarinic acid), in the GLW extract: apigenin, and in the GCW extract: daidzein, naringenin, and the derivates. In addition to significant differences in the quantitative and qualitative composition of the extracts analysed, their antioxidant activity was highly differentiated. The GCW extract neutralized the DPPH• radical to the greatest extent (IC₅₀ = 6.89 ± 0.56 μg/ml) and the W extract: the ABTS•+ radical (IC₅₀ = 31.44 ± 4.11 μg/ml). All the extracts had a comparable ability to chelate Fe²⁺ ions. The in vitro analysis of cytotoxicity of the extracts against the BJ human cell line (ATCC CRL-2522) demonstrated that the ET and W extracts were the most cytotoxic ones. The cytotoxicity of GLW and GCW extracts was comparable to the cytotoxicity of that of the solvents. The impact was proved of the solvents on the content, antioxidant properties, and cytotoxicity of P. crispum leaf extracts, and, at the same time, it was suggested that it would be possible to use those extracts in the food, pharmaceutical, and cosmetic industry

    Measuring impact of a quality improvement initiative on glaucoma clinic flow using an automated real-time locating system

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    Abstract Background Lean methodology helps maximize value by reducing waste, first by defining what value and waste are in a system. In ophthalmology clinics, value is determined by the number of patients flowing through the clinic for a given time. We aimed to increase value using a lean-methodology guided policy change, then assessed its impact on clinic flow using an automated radiofrequency identification (RFID) based real-time locating system (RTLS). Methods A total of 6813 clinical visits occurred at a single academic institution’s outpatient glaucoma clinic between January 5, 2018 to July 3, 2018. Over that period, 1589 patients comprising 1972 (29%) of visits were enrolled, with 1031 clinical visits occurring before and 941 visits after a policy change. The original policy was to refract all patients that improved with pinhole testing. The policy change was not to refract patients with a visual acuity ≥20/30 unless a specific request was made by the patient. Pre-post analysis of an automated time-motion study was conducted for the data collected 3 months before and 3 months after the policy change occurred on March 30, 2018. Changes to process and wait times were summarized using descriptive statistics and fitted to linear mixed regression models adjusting for appointment type, clinic volume, and daily clinic trends. Results One thousand nine hundred twenty-three visits with 1588 patients were included in the analysis. Mean [SD] age was 65.9 [14.7] years and 892 [56.2%] were women. After the policy change, technician process time decreased by 2.9 min (p < 0.0001) while daily clinical patient volume increased from 51.9 ± 16.8 patients to 58.4 ± 17.4 patients (p < 0.038). No significant difference was found in total wait time (p = 0.18) or total visit time (p = 0.83). Conclusions Real-time locating systems are effective at capturing clinical flow data and assessing clinical practice change initiatives. The refraction policy change was associated with reduced technician process time and overall the clinic was able to care for 7 more patients per day without significantly increasing patient wait time.http://deepblue.lib.umich.edu/bitstream/2027.42/173600/1/12886_2022_Article_2495.pd

    Orbital ordering in transition-metal spinels

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    Transition-metal spinels (general formula AB 2X 4) have been, for many years, the subject of intense experimental and theoretical activity. Structurally, the most interesting feature of these systems is the fact that the B cation occupies the nodes of a pyrochlore lattice, which is known to be geometrically frustrated. Therefore, one can explore how the natural tendency of the transition metals to order in the charge, magnetic and orbital sectors is affected by geometrical frustration. Recently, orbital ordering has become a topical subject in a variety of both non-frustrated systems, such as manganites and other perovskites, and in the spinels. In this paper, I review the recent experimental activity on the subject of orbital ordering in transition-metal spinels and relate this to models of orbital ordering that are being developed by theoreticians. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft
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