'End of term': teacher identities in a post-work context

There is a well-established literature that is concerned with the ways in which teachers construct their professional identities. There is also a great deal of research that has traced shifts in teacher identities across a career trajectory, the life-history approach. In the majority of this work the starting point and the finishing place has focused on the time spent actively engaged in teaching. This article explores teacher identity from another under-researched perspective. That is, what happens to teachers' identities when they no longer work as teachers, when they have perhaps laid down this aspect of their identity, when they have reached their 'end of term'? The purpose of this enquiry is two-fold. First, the intention is to critically explore theoretical constructions of teacher identities; second, the intention is to start to problematise both retirement as disengagement and life-stage approaches to teacher career and identity.

The article is organised as follows. First, I briefly review some of the different ways in which identity is understood and deployed. Then I consider some of the major research into teacher identity, the life-cycle of the teacher and some of the work on 'end-of career' teachers. The second half of the article draws on a small data set to explore the different ways that teachers have invested in their occupational identity, or not. It also charts what happens (to their teacher identities) when this occupation stops. Finally the article considers what those who used to teach can tell us about teacher identity and a job they no longer do.     

叶轮角度与流体黏度对高剪切罐内流体影响的模拟研究

采用标准k-ε模型及多重参考系法研究高剪切搅拌罐中叶轮角度与流体黏度改变对搅拌罐内混合流场、功率消耗、泵吸流量的影响。结果表明,高剪切搅拌罐中采用60°斜叶轮时流场具有较强烈的漩涡,泵吸流量和功率消耗也较大,同时定子射流半径也有所增加,具有较明显的优势。高剪切搅拌罐搅拌轴功率随着流体黏度的增大呈现先增大后减小的变化规律,在黏度为0.1～0.5Pa.s时功率最大;剪切头流量随着黏度的增大呈现出先降低后增大的趋势。     

Cosmetics considered in the context of physical attractiveness: a review

This review demonstrates the importance of outward appearance (especially of the face and head) in physical attractiveness and describes the methodology and results of objective experiments which assess interpersonal attraction, others' perceptions of the physically attractive and self-perception.
It shows that, although cosmetics have been used, inter alia , to manipulate physical attractiveness in some of these experiments, there are little data showing benefit of cosmetics per se to the individual.
Consequently, the review is a first step in designing objective studies to test the hypothesis that cosmetics are of demonstrable benefit to the user.
Les produits cosmetiques et l'attrait physique     

Children's hedonic response to berry products: Effect of chemical composition of berries and hTAS2R38 genotype on liking

The hedonic response of 104 healthy children, recruited from day-care centres and schools, to 12 different berry products with varying content of added sugar was studied. The berries used as ingredients were blackcurrant (Ribes nigrum), sea buckthorn (Hippophaë rhamnoides), bilberry (Vaccinium myrtillus), and lingonberry (Vaccinium vitis-idaea). Another aim of the study was to study the effects of the chemical composition of berries as well as children’s hTAS2R38 taste receptor genotypes on liking. The most liked product was bilberry with yoghurt, followed by bilberry juice, dried bilberries, and lingonberry rye bread. The most disliked products were sea buckthorn juice, sea buckthorn berries with yoghurt, and oatmeal with blackcurrant powder and berry oil. High total organic acid concentration was strongly related with a poor average liking score of the berries/berry products. A total of four different alleles of hTAS2R38 gene were observed in the study. Of the genotyped children, 45% were bitter taste insensitive individuals of the genotype AVI/AVI, and 40% were of the genotype PAV/AVI. Children of the genotype PAV/AVI were reported using more vegetables, but not berries, than the AVI/AVI children. The results also show that the liking scores of the children of the AVI/AVI, PAV/AVI, and PAV/PAV genotypes differed from each other, and that the familiarity of a berry product is likely to be an important factor in liking.     

Effects of residual phospholipids on surface properties of a soft-refined sunflower oil: Application to stabilization of sauce-types’ emulsions

Vinegar sauces’ type emulsions were prepared from water–alcohol mixture (90:10) and three different sunflower oil samples (Reference oil, SUN1 and SUN3) at 20 wt% with sunflower lecithin as O/W emulsifier. Besides the addition of lecithins at 0–2 wt%, the oil composition varied based on the minor components present in each oil due to the different crushing and refining process. Reference oil sample was nutrient-free while SUN oil contained nutrient component sterols, tocopherols, phosphorus and phenols. Interfacial tension of the different systems was monitored using an automated tensiometer. The vinegar sauces’ type oil-in-water emulsions were prepared by a two-step homogenization procedure (10,000 rpm for 10 min, followed by a passage through an homogenizer at 400 bar pressure), the lipid droplets’ stability against aggregation/coalescence was monitored using integrated light scattering (particle size distribution) and multiple light scattering (creaming) measurements for two-month storage at 4 °C. In the absence of added lecithins, SUN oil sample containing phospholipids presented lower interfacial tension values than the Reference oil. Equilibrium values obtained are ∼4.4 mN m⁻¹ for SUN3, ∼10.5 mN m⁻¹ for SUN1, instead of 13.7 mN m⁻¹ for Reference sample. Addition of phospholipids (lecithin) to the Reference sample led to a similar trend of adsorption kinetics observed in the SUN sample (nutrient rich oil). SUN3 showed the best ability to form elastic film and Reference oil showed lowest ability, which could be attributed to concentration and the composition of phospholipids.     

Criteria to define a more relevant reference sample of titanium dioxide in the context of food: a multiscale approach

ABSTRACT

Titanium dioxide (TiO₂) is a transition metal oxide widely used as a white pigment in various applications, including food. Due to the classification of TiO₂ nanoparticles by the International Agency for Research on Cancer as potentially harmful for humans by inhalation, the presence of nanoparticles in food products needed to be confirmed by a set of independent studies. Seven samples of food-grade TiO₂ (E171) were extensively characterised for their size distribution, crystallinity and surface properties by the currently recommended methods. All investigated E171 samples contained a fraction of nanoparticles, however, below the threshold defining the labelling of nanomaterial. On the basis of these results and a statistical analysis, E171 food-grade TiO₂ totally differs from the reference material P25, confirming the few published data on this kind of particle. Therefore, the reference material P25 does not appear to be the most suitable model to study the fate of food-grade TiO₂ in the gastrointestinal tract. The criteria currently to obtain a representative food-grade sample of TiO₂ are the following: (1) crystalline-phase anatase, (2) a powder with an isoelectric point very close to 4.1, (3) a fraction of nanoparticles comprised between 15% and 45%, and (4) a low specific surface area around 10 m² g^–1.     

Effects of urbanization on arable land requirements in China, based on food consumption patterns

China’s urbanization has led to changes in food consumption patterns. The effects of this population shift on the limited arable land resources available have not been clearly understood. Based on food consumption data in 1982, 1992 and 2002, we evaluated the arable land requirements needed to meet the demand of Chinese food consumption patterns and the countermeasures that could mitigate the increasing pressure on this limited resource. The results indicated that processed food (including plant oil, alcohol and sugar) needed the most arable land for production, followed by livestock-based food and plant-based food, which needed the least. The arable land requirement for food consumption of urban residents was higher than that of rural residents in all 3 years, 1982, 1992 and 2002 and both decreased from 1982 to 2002. Based on the data for these years, the total arable land requirement for Chinese food consumption is projected to increase from 1982 to 2030, and then gradually decreases from 2040 to 2050. The food demand pressures put on the limited arable land resources in China is exacerbated by trends in food consumption patterns—i.e. more livestock-based and less plant-based food, and the need to improve the nutritional intake of both urban and rural populations. To alleviate the pressures, Chinese food consumption patterns should be changed so that less livestock-based and more plant-based food is consumed. Two other mitigation options are to increase the import of land-intensive food and to invest in agricultural research and development. These findings could be helpful in optimizing the interrelationships between the limited arable land resources available and food consumption patterns during the continuing rapid urbanization of China.     

Further studies on n-nitrosopyrrolidine and its precursors: Effects of ascorbic acid and vitamin E on tumor development in mice as related to consumption of cured meat

Two experiments were carried out to ascertain if supplementation of a semipurified diet to Swiss-ICR mice with either ascorbic acid (AA), vitamin E (Vit E) or a combination of the two would modulate the carcinogenic effects of N-nitrosopyrrolidine (NPyr) and of its probable precursors (nitrite-N0(2) and pyrrolidine-Pyr) in Experiment I or of NPyr in Experiment II. Results indicated that neither AA nor Vit E modulated the carcinogenic effects of NPyr or of its probable precursors (NO(2) and Pyr). Results verified a previous report from our laboratory showing that NPyr increased the number of malignant tumors by some 5-8 fold over controls. There was a lower incidence of tumors in the control group on the semi-purfied diet than in the groups given NO(2) and Pyr, although both treatments had a low frequency of malignant tumors (1 63 versus 5 72 survivors). Results support our earlier study suggesting that neither NO(2) nor Pyr alone or in combination together contribute to cancer-at least in the laboratory mouse.     

Radiative forcing impacts of boreal forest biofuels: a scenario study for Norway in light of albedo

Radiative forcing impacts due to increased harvesting of boreal forests for use as transportation biofuel in Norway are quantified using simple climate models together with life cycle emission data, MODIS surface albedo data, and a dynamic land use model tracking carbon flux and clear-cut area changes within productive forests over a 100-year management period. We approximate the magnitude of radiative forcing due to albedo changes and compare it to the forcing due to changes in the carbon cycle for purposes of attributing the net result, along with changes in fossil fuel emissions, to the combined anthropogenic land use plus transport fuel system. Depending on albedo uncertainty and uncertainty about the geographic distribution of future logging activity, we report a range of results, thus only general conclusions about the magnitude of the carbon offset potential due to changes in surface albedo can be drawn. Nevertheless, our results have important implications for how forests might be managed for mitigating climate change in light of this additional biophysical criterion, and in particular, on future biofuel policies throughout the region. Future research efforts should be directed at understanding the relationships between the physical properties of managed forests and albedo, and how albedo changes in time as a result of specific management interventions.     

Application of turbulent pulsating flows to the bacterial removal during a cleaning in place procedure. Part 2: Effects on cleaning efficiency

Pulsating turbulent flows effects on cleaning in place procedure of straight pipes were investigated for various pulsations parameters (frequency and amplitude) and mean velocities of the flow. Pulsations generation was made with a new system which allows high amplitude of pulsations. Experiments showed the contribution of the different pulsation parameters, in the removal of adhered bacterial spores, in addition to the effect of the mean velocity of the flow. A high level of the cleaning rate is observed despite the reduction of the magnitude of the mean velocity. This result can be explained by the effect of the two pulsations parameters (amplitude and frequency) which ensure a high wall shear rate. The study of the cleaning kinetics has shown the increase of the removal constant rate of spores using pulsed flow in comparison with the use of a steady turbulent flow.     

Observations on the inhibition of vegetative cells of Clostridium sporogenes by nitrite which has been autoclaved in a laboratory medium, discussed in the context of sub-lethally processed cured meats

Summary. The ability of sodium nitrite incorporated in a laboratory medium to inhibit an inoculum of vegetative Clostridium sporogenes is greatly influenced by the temperature at which the nitrite containing medium is held prior to inoculation. At pH values of 6.0 and above, the inhibitory effect of a given concentration of nitrite is substantially enhanced when it is first autoclaved in the medium. It is believed that the nitrite, on heating, reacts with some component of the medium producing an unknown substance which is extremely inhibitory to the vegetative growth of Cl. sporogenes . The inhibitory activity of this unknown substance is very different from the inhibitory activity of sodium nitrite. The possible significance of these observations in relation to the stability of sublethally processed cured meats is discussed.     

Effects of probiotic yogurt consumption on metabolic factors in individuals with nonalcoholic fatty liver disease

The aim of this study was to investigate the effects of probiotic yogurt consumption on some metabolic factors in nonalcoholic fatty liver disease (NAFLD) patients. This double-blind, randomized, controlled clinical trial was conducted on 72 patients with NAFLD (33 males and 39 females) aged 23 to 63 yr. Subjects in the intervention group (n = 36) consumed 300 g/d of probiotic yogurt containing Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 and those in the control group (n = 36) consumed 300 g/d of conventional yogurt for 8 wk. Fasting blood samples, anthropometric measurements, and dietary records (24 h/d for 3 d) were collected at baseline and at the end of the trial. Probiotic yogurt consumption resulted in reductions of 4.67, 5.42, 4.1, and 6.92% in serum levels of alanine aminotransferase, aspartate aminotransferase, total cholesterol, and low-density lipoprotein cholesterol, respectively, compared with control group. No significant changes were observed in levels of serum glucose, triglycerides, or high-density lipoprotein cholesterol in either group. Probiotic yogurt consumption improved hepatic enzymes, serum total cholesterol, and low-density lipoprotein cholesterol levels in studied subjects and might be useful in management of NAFLD risk factors.     

Dietary manipulation in dairy cattle: laboratory experiments to assess the influence on ammonia emissions

Improvements to the efficiency of dietary nitrogen use by lactating dairy cattle can be made by altering the concentration and form of protein in the diet. This study collected urine and feces from dairy cows from selected crude protein (CP) treatments of 2 lactation studies. In the first trial, collections were made from cattle fed a diet with high (19.4%) or low (13.6%) CP content (HCP and LCP, respectively). In the second trial, collections were made from cattle fed diets in which the forage legume component was alfalfa (ALF) or birdsfoot trefoil with a low (BFTL) or high (BFTH) concentration of condensed tannins (CT). A system of small laboratory chambers was used to measure NH3 emissions over 48 h from applications of equal quantities of urine and feces to cement (simulating a barn floor) and from applications of slurries, made by combining feces and urine in the proportions in which they were excreted for each treatment, to soil. Reducing dietary CP content resulted in less total N excretion and a smaller proportion of the excreted N being present in urine; urine N concentration was 90% greater for HCP than LCP. Surprisingly, NH3 emissions from the barn floor were similar in absolute terms despite the great differences in urine urea-N concentrations, presumably because urease activity was limiting. Cumulative emissions from fresh slurries applied to soil represented 18% of applied N for both HCP and LCP. Following storage at 20 degrees C for 2 wk, cumulative emissions from LCP were much lower than for HCP, representing 9 and 25% of applied N, respectively. Emissions were also lower when expressed as a proportion of slurry total ammoniacal N (TAN) content (24 and 31%, respectively) because of treatment differences in slurry pH. Increasing CT content of the dietary forage legume component resulted in a shift in N excretion from urine to feces. Cumulative NH3 emissions from the barn floor were greater for ALF than for BFTL or BFTH. Emissions from fresh and stored slurries were in proportion to slurry TAN contents, with approximately 35% of applied TAN being lost for all treatments. Emissions expressed as a proportion of total N applied were consistently lower for BFTH than for ALF.     

Efficacy of a commercial produce wash on bacterial contamination of lettuce in a food service setting

Many microorganisms (including a number of important foodborne pathogens) can be present on raw fruits and vegetables. Since these products are frequently eaten raw, any pathogens present represent a potential risk to the consumer. The objective of this study was to compare the efficacy of a commercial produce wash with that of water for reducing the total bacterial population on lettuce when used by food service employees in university dining halls. Because this study was carried out in actual food service facilities during their daily operation, we used indigenous produce microflora instead of actual pathogens. Over the course of the study, more than 40 heads of lettuce were divided into thirds, and each section was analyzed for total plate count either before washing, after washing in water, or after washing in Victory produce wash. When initial contamination levels were > or = 100 CFU/g (n = 36 samples), reductions obtained with Victory produce wash (1.8 log CFU/g) were significantly larger (P = 0.0006) than those obtained with water (0.8 log CFU/g). Our results indicate that Victory produce wash is effective in reducing indigenous flora on lettuce during food service preparation. Our results also show that care must be taken in the analysis of microbial reduction data: only a slight reduction in total plate count (ca. 0.1 log CFU/g) and no significant difference in reductions (P = 0.84) were observed when all samples (irrespective of initial contamination level) were compared.     

Effects of dietary consumption of cranberry powder on metabolic parameters in growing rats fed high fructose diets

The effect of dietary consumption of a cranberry powder (CP) containing increased amounts of procyanidins and other phytochemicals on metabolic parameters associated with metabolic syndrome was investigated in growing rats fed a high fructose diet. Dietary treatments were control (starch based), high fructose (HF), and HF containing either 3.3, 6.6, or 33 g CP/kg diet. Fasting plasma glucose and triglycerides tended to be higher with HF feeding and were reduced by feeding CP. The area under curve following an oral glucose tolerance test was 35-50% higher in animals fed HF diet vs. control and was decreased to control levels by the low or medium but not high CP diet. Feeding CP tended to lower fasting plasma insulin. Homeostatic models of insulin resistance (HOMA-IR) and β-cell function (HOMA-BCF) were lowest in animals fed low or medium CP diets (p < 0.05). Rats fed the control starch diet had slightly higher food intake, final body weight, and abdominal fat compared to animals fed other diets. Kidney weight was higher in HF group and feeding CP decreased kidney weight to normal levels. In the fed state, plasma triglyceride was increased with HF diet, whereas insulin was lower in animals fed HF diet. Overall, inclusion of CP in the diet was effective in modulating some aspects of metabolic parameters associated with metabolic syndrome and the medium level of CP in the diet produced a better response than the lower and higher CP levels.     

Biodegradation of acidic pharmaceuticals in bed sediments: insight from a laboratory experiment

Pharmaceutical residues are commonly detected micropollutants in the aquatic environment. Biodegradation in sediments is a potentially significant removal process for these compounds in rivers which is constrained by the transfer of water and solutes into the sediment. The aim of this study was to determine the combined effect of flow velocity and sediment dynamics and thus of water-sediment interactions on the attenuation of 6 acidic pharmaceuticals. We carried out experiments with river water and sediment in a bench-scale annular flume at two different hydraulic boundary conditions (flat sediment surface vs moving sediment). The effective biodegradation half-lives of 4 compounds (diclofenac, bezafibrate, ibuprofen, naproxen) were in the range of 2.5 to 18.6 days and were much shorter when the exchange of surface and pore water was fast. For gemfibrozil, a half-life of 10.5 d was determined in the experiment with moving sediment, whereas no degradation was observed with flat sediment bed. These findings can be attributed to the limited transfer of water and solutes into the sediment at low flow velocity and flat sediment bed which rapidly induced anaerobic conditions in the sediment. The only compound that was efficiently removed in deeper, anoxic sediment layers was naproxen. The calculated half-life distances in rivers ranged from 53 to 278 km. Our results indicate that it could be favorable to increase the rate of exchange between surface and pore water during river restoration to enhance the attenuation of organic micropollutants like acidic pharmaceuticals.     

Hair mercury levels in relation to fish consumption in a community of the Moroccan Mediterranean coast

Coastal populations with high seafood consumption in the Mediterranean have a significant exposure to dietary methylmercury, and areas where environmental mercury pollution is an issue due to industrial activities are of special concern. The study was undertaken with the aim of assessing methylmercury exposure through fish consumption in a community of north Morocco and characterizing the relevant health risk. Concentrations of total mercury were determined in human hair, a biomarker of methylmercury exposure, and in locally consumed fish by cold vapour atomic absorption spectrophotometry. Based on consumption frequencies reported by the 108 subjects included in the study the weekly intake of methylmercury was estimated and biomarker data were evaluated in relation to the estimated intake and the sociodemographic characteristics of the population. Multiple regression analysis was employed for the interpretation of hair mercury data in relation to fish consumption frequency, gender and the age of individuals. Mercury concentrations in hair ranged from 0.22 to 9.56 µg g^-1 (geometric mean = 1.79 µg g^-1) and were closely related to fish intake. Fisherman and their families consumed fish three to five times per week and were the most exposed population subgroup. A high proportion of women of child-bearing age (50%) had relatively high levels of mercury in their hair (3.08-7.88 µg g^-1).     

Commit to Quit in the YMCAs: translating an evidence-based quit smoking program for women into a community setting.

Approximately 22% of women continue to smoke cigarettes despite the increased risk of cancer associated with smoking. Regular aerobic exercise added to our Commit to Quit smoking cessation program for women improved cessation rates compared with the same cessation program plus equal contact time. This trial tested the feasibility of conducting Commit to Quit in the YMCA setting. Among the 77 women who attended informational sessions, 68% (n = 52) were eligible and 56% (N = 43) enrolled in one of five cohorts. All cohorts received the same intervention: the Commit to Quit smoking cessation program, led by Ph.D.-level psychologists, coupled with the YMCA Personal Fitness Program, led by YMCA personal trainers. On quit day in the program 17 women (39.5%) reported a 24-hr quit, and by the end of treatment 3 women (7.0%) reported a 7-day quit. Intent-to-treat analysis (baseline values carried forward) revealed a decrease in the mean number of cigarettes smoked from 9.9 at baseline (SD = 5.0) to 4.8 at the end of treatment (SD = 5.2; t = 4.7; p<.001). Self-reported exercise increased from 530.3 kcal (SD = 587.0) at baseline to 1,256.4 kcal (SD = 1,263.1) at end of treatment (t = -2.489 p = .017). Participants reported high ratings of satisfaction with the smoking cessation program and Personal Fitness Program. Preliminary feasibility and acceptability were demonstrated as we translated an evidence-based intervention into the YMCA setting.