Changes in pH of Milk During Freezing and Frozen Storage

Summary Measurement of pH during freezing and frozen storage of pasteurized and raw milk and of raw milk with added calcium, phosphate, and citrate showed that marked pH changes occurred in frozen milk. During slow freezing, the pH of milk decreased to values as low as 5.8, whereas little change in pH occurred during fast freezing. During storage at −7° C. as well as at −12° C. the pH decreased to a minimum during the first 2 to 3 wk. of storage, and increased gradually thereafter. The pH minimum of pasteurized milk and raw milk with added salt (5.8–6.0) was generally lower than that of raw milk (6.1–6.2). The increase in pH after the pH minimum was reached was more gradual in pasteurized milk and raw milk with added chemicals than in raw milk. Although the amount of precipitated protein was measured simultaneously with pH, the data did not indicate a definite relation between pH changes and protein precipitation

Overweight and obesity in six-year-old children in 4th and 5th quintile schools in Mangaung, South Africa

Objective: Weight status at age six years has been identified as an important predictor of overweight and obesity in adolescence, which, inturn, tracks into adulthood, increasing the risk of future metabolic diseases. This study aimed to describe the prevalence of overweight andobesity in six-year-old children in 4th and 5th quintile schools in Mangaung as part of a campaign to raise awareness of the problem among parents and educators.Design: The study design was cross-sectional and descriptive.Subjects and setting: Ninety-nine randomly selected grade 1 children, born in 2007, in 4th and 5th quintile primary schools, Mangaung, were the study subjects.Method: Body mass index (BMI) and waist-to-height ratio (WHtR) were recorded.Results: Based on BMI-for-age, 24.2% of the children were overweight and obese (10.9% of the boys and 11.3% of the girls were overweight; and 10.9% of the boys and 15.1% of the girls were obese). WHtR was above  normal in 16.2% of the study sample (8.7% of the boys and 22.6% of girls). WHtR correlated significantly with BMI (R 0.8, p-value < 0.0001) in this sample.Conclusion: Almost a quarter of the six-year-old children in this study were overweight and obese. Parents need to be made more aware of future  morbidities associated with excess weight at this age and be empowered to prevent, recognise and appropriately address weight problems in their children

Energy and temperature fluctuations in the single electron box

In mesoscopic and nanoscale systems at low temperatures, charge carriers are typically not in thermal equilibrium with the surrounding lattice. The resulting, non-equilibrium dynamics of electrons has only begun to be explored. Experimentally the time-dependence of the electron temperature (deviating from the lattice temperature) has been investigated in small metallic islands. Motivated by these experiments we investigate theoretically the electronic energy and temperature fluctuations in a metallic island in the Coulomb blockade regime, tunnel coupled to an electronic reservoir, i.e. a single electron box. We show that electronic quantum tunnelling between the island and the reservoir, in the absence of any net charge or energy transport, induces fluctuations of the island electron temperature. The full distribution of the energy transfer as well as the island temperature is derived within the framework of full counting statistics. In particular, the low-frequency temperature fluctuations are analysed, fully accounting for charging effects and non-zero reservoir temperature. The experimental requirements for measuring the predicted temperature fluctuations are discussed.Comment: 20 pages, 4 figures, submitted to NJP special issue on Quantum Thermodynamic

Factoranalyse voor het verklaren van opbrengst- en gehalteverschillen tussen percelen cichorei : factoranalyse uitgevoerd op de I-top databestanden van de jaren 2003, 2004, 2005 en 2006

In de cichoreiteelt wordt sinds 2003 gewerkt met het teeltregistratiesysteem I-top. In dit systeem wordt geregistreerd hoe de teelt op de diverse percelen wordt uitgevoerd. Het doel van het systeem is om inzicht te krijgen in de teeltfactoren die met name de wortelopbrengst, het inulinegehalte en de inuline-opbrengst van de cichorei bepalen. Op basis van dit inzicht kan de teeltadvisering verbeterd worden, terwijl daarnaast ook vastgesteld kan worden aan welke factoren eventueel extra onderzoek nodig is. In het onderzoek dat in dit rapport beschreven wordt is een factoranalyse uitgevoerd op de databestanden van de jaren 2003 t/m 2006. Met behulp van een factoranalyse kan inzicht verkregen worden in de samenhang tussen de variabelen die in de datasets aanwezig zij

Double strand DNA cleavage with a binuclear iron complex

Covalently linking two single strand DNA cleaving agents resulted in a new biomimetic binuclear iron complex capable of effecting oxidative double strand DNA cleavage.

Out of Equilibrium Solutions in the XYXY-Hamiltonian Mean Field model

Out of equilibrium magnetised solutions of the $XY$-Hamiltonian Mean Field ($XY$-HMF) model are build using an ensemble of integrable uncoupled pendula. Using these solutions we display an out-of equilibrium phase transition using a specific reduced set of the magnetised solutions

Herbal weight-loss products: how informed are we?

Objective: Non-prescription, weight-loss products are advertised as quick-solution alternatives to long-term lifestyle changes.Design: Cross-sectional descriptive.Setting: Free State province.Subjects: Fifty-six dietitians registered to the Free State branch of the Association of Dietetics in South Africa, excluding lecturers and students, and 88 pharmacists working in the Bloemfontein area.Outcome measures: Structured telephonic interviews were conducted with 25 dietitians and 46 pharmacists to ascertain whether or not they had heard of the individual ingredients listed in non-prescription, weight-loss products and if they knew if each of these ingredients were scientifically proven to induce weight loss.Results: Most dietitians and pharmacists reported that they had heard of green tea extract (92% and 89%), chromium picolinate (76% and 59%), apple cider vinegar (100% and 96%), lemon juice (100% and 87%) and alcohol (100% and 91%), respectively, being ingredients in weight-loss products. More dietitians and pharmacists reported that, to their knowledge, green tea extract (52% vs. 26%), chromium picolinate (52% vs. 15%), apple cider vinegar (64% vs. 33%), lemon juice (80% vs. 64%) and alcohol (76% vs. 61%), were not scientifically proven to be effective in attaining weight loss. Both groups included a percentage who were not familiar with the ingredients, or who thought that these ingredients had been demonstrated to be effective, despite no conclusive evidence existing in the literature.Conclusion: Healthcare professionals need to actively educate themselves about non-prescription weight-loss products in order to guide the public and reduce consumer confusion