2,035 research outputs found

    The influence of yeasts on the aroma of Stilton cheese

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    Blue cheeses comprise secondary microbial flora which is not controlled during production. The secondary flora of Stilton comprises distinct yeast communities in each section of the cheese (blue veins, white core, outer crust). Previous work has identified yeasts species-specific effects on aroma development. However, large variation between replicates was observed and this emulates the problem faced by the industry in achieving product consistency. Stilton shows variation in aroma between and within batches produced. In the present study factors influencing yeasts' impact on aroma variation were investigated by incubating Stilton yeast isolates in milk-based models, with and without the mould Penicillium roqueforti, which is the major contributor to blue cheese aroma development. Resultant aroma profiles of models were analysed via Solid-Phase Microextraction Gas Chromatography-Mass Spectrometry (SPME GC-MS) and Principal Component Analysis (PCA). Sensory studies (Flash Profile, Napping®, Triangle, Paired Comparison and Constant Reference ranking tests) were conducted to determine whether findings were perceivable by humans. The concentration of yeasts and growth conditions of the models influenced aroma generation. The production of ketones, major contributors to blue cheese aroma, increased as the concentration of Yarrowia lipolytica, inoculated into models containing P. rouqeforti, increased. Variation in the aroma profiles of replicate samples decreased as the concentration of Kluyveromyces lactis, inoculated into models containing P. roqueforti, decreased. Sensory analysis indicated the effects of Y. lipoltyica and K. lactis on aroma profiles observed instrumentally may not be perceivable by humans. The results of this study suggest that yeasts could be used as adjuncts in Stilton production to manipulate the production of aroma compounds and limit variation in aroma profiles

    Determination of extracellular fluid volume in healthy and azotemic cats

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    BACKGROUND: Methods for determining extracellular fluid volume (ECFV) are important clinically for cats. Bromide dilution has been studied in cats to estimate ECFV. Markers of GFR also distribute in ECFV and can be used for its measurement. HYPOTHESIS/OBJECTIVES: The primary objective was to develop a method of determining ECFV from iohexol clearance in cats and evaluate agreement with that determined using bromide dilution. Additional objectives were to compare ECFV between azotemic and nonazotemic cats and evaluate appropriate methods of standardizing ECFV. ANIMALS: Client‐owned cats with varying renal function. METHODS: Validation of ECFV determined from slope‐intercept iohexol clearance was performed in 18 healthy nonazotemic cats. ECFV was then determined using the validated method and bromide dilution and agreement assessed. Appropriateness of standardization to body weight (BW) and body surface area (BSA) was evaluated. RESULTS: Extracellular fluid volume determined from slope‐intercept iohexol clearance and bromide dilution was 0.84 ± 0.32 L and 0.85 ± 0.19 L (mean ± SD), respectively. There were wide limits of agreement between the methods (−0.58 to 0.54 L) and therefore, agreement was considered to be poor. ECFV did not differ significantly between azotemic and nonazotemic cats (P = .177). BSA was found to be the best method for standardizing ECFV measurement in cats. CONCLUSIONS AND CLINICAL IMPORTANCE: This study developed a method for determining ECFV from slope‐intercept iohexol clearance which provides simultaneous assessment of renal function and an estimate of ECFV. ECFV does not differ between azotemic and nonazotemic cats, which suggests fluid volume loss or overload is not an important clinical feature in cats with mild chronic kidney disease

    Reading instruction in first-grade classrooms: Do basals control teachers?

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    This study describes first-grade teachers beliefs and practices about reading instruction. Drawing from interview and observational data, 16 teachers from four districts were placed on a continuum from skills-based to literature-based in relationship to their use of the basal. Only 2 teachers were found to rely solely on the basal, while 3 teachers enhanced the basal with literature, and 4 teachers used only literature in their reading instruction. Six teachers enhanced their basal use with additional skills and 1 teacher relied on skills only in her reading instruction. This diversity\u27 of teaching beliefs and practices was corroborated by questionnaire data from a larger sample of teachers. Next, a framework developed by Belenky, Clinchy, Goldberger, and Tarule (1986) was used to categorize teachers\u27 ways of knowing. The findings showed 1 teacher to be a silent knower, 6 were received knowers, 1 was a subjective knower, 7 were procedural knowers, and 1 was a connected knower. Results challenge Shannon\u27s (1987) hypothesis that basals deskill teachers while supporting Sosniak and Stodolskv\u27s (1993) view that teachers are more autonomous in their use of textbook materials

    A Youth Perspective: The 4-H Teen’s Leadership Identity Development Journey

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    A current focus of youth-serving organizations is youth leadership development with an objective of helping youth become productive contributors to society. 4-H is a leading organization in the effort to expose youth to leadership opportunities. This study examined the leadership identity development of 4-H youth serving in statewide leadership positions. The Leadership Identity Development (LID) model and mentoring mosaic served as the conceptual framework in this study. The purpose of this qualitative study is to shed light on the question, how do 4-H teens describe their journey to leadership? Youth reflected on the experiences, examples, and influences that impacted their leadership journey. The most common response for experiences that led to a 4-H youth’s choice to pursue a leadership role was a previous leadership experience. Leadership traits, Extension agents, and historical figures were the most frequently identified examples of leadership, and family members and Extension agents were commonly identified as influences. Four themes emerged from the youth perspectives: (1) leaders are characterized by traits, (2) individual-focused leaders, (3) team-oriented individuals, and (4) community contributors. The results corroborated with Stages 2-4 in the LID model. This study is a starting point for exploring leadership identity development of youth

    The effect of β-cyclocitral treatment on the carotenoid content of transgenic Marsh grapefruit (Citrus paradisi Macf.) suspension-cultured cells

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    Zheng, Xiongjie, Zhu, Kaijie, Ye, Junli, Price, Elliott J., Deng, Xiuxin, Fraser, Paul D. (2020): The effect of β-cyclocitral treatment on the carotenoid content of transgenic Marsh grapefruit (Citrus paradisi Macf.) suspension-cultured cells. Phytochemistry (112509) 180: 1-8, DOI: 10.1016/j.phytochem.2020.112509, URL: http://dx.doi.org/10.1016/j.phytochem.2020.11250

    Application of 96-well plate SPE method for analysis of persistent organic pollutants in low volume blood serum samples

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    Though many persistent organic pollutants (POPs) are closely regulated the human population is still exposed to these ubiquitous chemicals from the environment and diet. Safe management and human biomonitoring of POPs is necessary to understand the risk of exposure. Within human biomonitoring the mass of sample is often limited, therefore robust methods using smaller sample amounts are necessary. This study developed a 96-well plate solid phase extraction (SPE) method for determination of selected POPs: polychlorinated biphenyls (PCBs), organo-chlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and non-persistent novel flame retardants (NFRs) in low volume blood serum. Non-destructive clean-up coupling Oasis HLB extraction plate with Phree phospholipid removal plate was employed. Extraction efficiency was determined at low and high concentrations in certified reference materials NIST SRM 1957 and 1958, respec-tively. Target compounds deviated from certified values on average by 15% and 21% for SRM 1957 and SRM 1958, respectively. Observed limit of detections (LODs) ranged from 0.36 pg/mL (PCB 180) to 66.07 pg/mL (delta-HCH). The applicability for real samples is demonstrated on 48 samples from pregnant women enrolled in the pilot phase of the CELSPAC: TNG study. In total, 30 target compounds were detected in at least one sample. The method developed here provides a fast and reliable analysis of human blood serum with possibility to introduce automation for the sample preparation procedure

    Towards an equitable digital society:artificial intelligence (AI) and corporate digital responsibility (CDR)

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    In the digital era, we witness the increasing use of artificial intelligence (AI) to solve problems, while improving productivity and efficiency. Yet, inevitably costs are involved with delegating power to algorithmically based systems, some of whose workings are opaque and unobservable and thus termed the “black box”. Central to understanding the “black box” is to acknowledge that the algorithm is not mendaciously undertaking this action; it is simply using the recombination afforded to scaled computable machine learning algorithms. But an algorithm with arbitrary precision can easily reconstruct those characteristics and make life-changing decisions, particularly in financial services (credit scoring, risk assessment, etc.), and it could be difficult to reconstruct, if this was done in a fair manner reflecting the values of society. If we permit AI to make life-changing decisions, what are the opportunity costs, data trade-offs, and implications for social, economic, technical, legal, and environmental systems? We find that over 160 ethical AI principles exist, advocating organisations to act responsibly to avoid causing digital societal harms. This maelstrom of guidance, none of which is compulsory, serves to confuse, as opposed to guide. We need to think carefully about how we implement these algorithms, the delegation of decisions and data usage, in the absence of human oversight and AI governance. The paper seeks to harmonise and align approaches, illustrating the opportunities and threats of AI, while raising awareness of Corporate Digital Responsibility (CDR) as a potential collaborative mechanism to demystify governance complexity and to establish an equitable digital society

    Literature-based reading instruction: Problems, possibilities & polemics in the struggle to change

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    Concerns are being raised in both professional literature as well as in the popular press regarding certain aspects of the literature-based movement. Here we report on findings from a longitudinal study of a group of first -grade teachers who have been attempting (with varying degrees of success)to introduce literature-based teaching strategies into their classrooms. We inspect the experiences of these teachers in relation to four areas of concern that have been raised regarding literature-based teaching: 1. skills instruction; 2.guided reading strategies; 3. literature selection;and 4. thematic teaching (or curriculum integration). We describe classroom practices and the 9 problems and possibilities associated with teacher change in each of the four areas
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