Reduced insulin-like growth factor-I after acute feed restriction in lactating dairy cows is independent of changes in growth hormone receptor 1A mRNA

Growth hormone receptor (GHR) and insulin-like growth factor-I (IGF-I) mRNA decrease in the liver of dairy cows at parturition. Epinephrine is released and feed intake is decreased at the same time. The objective of this study was to determine whether feed restriction and (or) administration of epinephrine could recapitulate the changes in the hepatic GHR 1A and IGF-I mRNA that occur at parturition. Eight lactating cows were randomly assigned to one of two rations (ad libitum or restricted). The cows assigned to the restricted ration were fed 75, 60, 60, and 25% of feed consumed by the ad libitum cows on successive days to mimic the changes in feed intake around parturition. Liver samples were collected by needle biopsy before and after feed restriction. Cows received either 0.02 mg/kg of epinephrine or saline approximately 24 h before the second liver biopsy so that a 2 x 2 factorial arrangement of treatments was created. Feed restriction increased plasma nonesterified fatty acids and liver triglyceride percentages and decreased plasma IGF-I concentrations. The decrease in plasma IGF-I after feed restriction was associated with a decrease in IGF-I mRNA in feed-restricted cows. The amount of GHR 1A mRNA did not change after feed restriction. Epinephrine treatment did not affect the amount of GHR 1A or IGF-I mRNA. We conclude that the decrease in feed intake at parturition may be partially responsible for the decrease in IGF-I but may not cause the decrease in GHR 1A.     

Effects of processing conditions on the quality of vacuum‐fried carrot chips

The effects of pretreatment and vacuum frying conditions on the quality of fried carrot chips were studied. The moisture and oil contents of fried carrot chips were significantly (p < 0.05) reduced when blanched carrot slices were pretreated by immersion in fructose solution and freezing prior to vacuum frying. Furthermore, more uniform porosity was observed on the vertical cross‐section of carrot chips when examined by scanning electron microscopy. During vacuum frying, the moisture content, colour and breaking force of carrot chips decreased while the oil content increased with increasing frying temperature and time. However, there was no apparent change in Hunter ΔE with time when the frying temperature was below 100 °C and the frying time was below 25 min. Results of this study suggest that vacuum frying at moderate temperature (90–100 °C) for 20 min can produce carrot chips with lower moisture and oil contents as well as good colour and crispy texture. Copyright © 2005 Society of Chemical Industry     

Reactive transport in porous media: a comparison of model prediction with laboratory visualization

Groundwater transport models that accurately describe spreading of nonreactive solutes in an aquifer can poorly predict concentrations of reactive solutes. The dispersive term in the advection-dispersion equation can overpredict pore-scale mixing, and thereby overpredict homogeneous chemical reaction. We quantified this experimentally by imaging instantaneous colorimetric reactions between solutions of aqueous CuSO4 and EDTA4- within a 30-cm long translucent chamber packed with cryolite sand that closely matched the optical index of refraction of water. A charge-coupled device camera was used to quantify concentrations of blue CuEDTA2- within the chamber as it was produced by mixing of the two reactants at different flow rates. We compared these experimental results with a new analytic solution for instantaneous bimolecular reaction coupled with advection and dispersion of the product and reactants. For all flow rates, the concentrations of CuEDTA2- recorded in the experiments were about 20% less than predicted by the analytic solution, thereby demonstrating that models assuming complete mixing at the pore scale can overpredict reaction during transport.     

Analysis of cured meat products for cryptosporidium oocysts following possible contamination during an extensive waterborne outbreak of Cryptosporidiosis

An outbreak of waterborne cryptosporidiosis in a town in northern Sweden during winter 2010 resulted in the potential exposure of cured meat products to Cryptosporidium oocysts during their manufacture. The purpose of this work was to develop a method for analyzing cured meat products for contamination with Cryptosporidium oocysts and use this method to analyze potentially contaminated product samples. A simple method of elution, concentration, separation, and detection was used, based on work with other food matrices but adapted for the relatively high fat content of cured meat surfaces. Using spiking experiments, the recovery efficiency of this method was found to be over 60%. In the analysis of the potentially contaminated products, only one putative Cryptosporidium oocyst was detected, and this was sufficiently deformed so that it could not be confirmed as an oocyst; if it was an oocyst, it was considered to have been probably deformed and inactivated prior to analysis. Based on the results of the analyses, together with data on the probable extent of contamination of the products and on our knowledge of factors, such as water activity, which affect oocyst survival, the products were safely released to the market.     

Application of electron spin resonance (ESR) spectrometry in nutraceutical and food research

Electron spin resonance (ESR) spectroscopy is able to directly measure the chemical species with unpaired electrons and has been widely used in a number of research fields. This review focused on its application in nutraceutical and food research. Current status of ESR in free radical scavenging capacity estimation, food oxidative stability evaluation, Cu(2+) chelating capacity determination were summarized. Also discussed was the potential of ESR spin-label oximetry technique in examination of lipid peroxidation and oxygen diffusion-concentration products in liposomes, oxygen transport and depletion, and membrane structure and dynamic properties. In addition, ESR application in identifying and estimating irradiated foods including meat, fruits, vegetables, spices, cereal grains, and oil seeds was reviewed. Finally, the potential use of ESR technique in investigating microstructure change, phase transition and viscosity related properties during food formulation, processing, and storage was briefly mentioned, along with its potential in determination of radio-stability of food components. This review may provide some fundamental knowledge of ESR and its application in nutraceutical and food research.     

Open dumping site in Asian developing countries: a potential source of polychlorinated dibenz-p-dioxins and polychlorinated dibenzofurans

Open landfill dumping areas for municipal wastes in Asian developing countries have recently received particular attention with regard to environmental pollution problems. Because of the uncontrolled burning of solid wastes, elevated contamination by various toxic chemicals including dioxins and related compounds in these dumping sites has been anticipated. In this study, concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (PCBs) were determined in soils from dumping sites in the Philippines, Cambodia, India, and Vietnam. Residue concentrations of PCDD/Fs and coplanar PCBs in dumping site soils were apparently greater than those in soils collected in agricultural or urban areas far from dumping sites, suggesting that dumping sites are potential sources of PCDD/Fs and related compounds. Observed PCDD/F concentrations in soils from dumping sites in the Philippines and Cambodia were comparable or higher than those reported for dioxin-contaminated locations in the world (e.g., near the municipal waste incinerators and open landfill dumping sites). Homologue profiles of PCDD/Fs in dumping site soils from the Philippines and, to a lesser extent, from Cambodia and India reflected patterns of samples representing typical emissions, while profiles of agricultural or urban soils were similar to those of typical environmental sinks. This result suggests recent formation of PCDD/Fs in dumping site areas and that open dumping sites are a potential source of dioxins in Asian developing countries. Uncontrolled combustions of solid wastes by waste pickers, generation of methane gas, and low-temperature burning can be major factors for the formation of dioxins in dumping sites. Elevated fluxes of PCDD/Fs to soils in dumping sites were encountered in the Philippines, Cambodia, India, and Vietnam-Hanoi, and these levels were higher than those reported for other countries. Considerable loading rates of PCDD/Fs in the dumping sites of these countries were observed, ranging from 20 to 3900 mg/yr (0.12-35 mg TEQ/yr). PCDD/F concentrations in some soil samples from the Philippines, Cambodia, India, and Vietnam-Hanoi exceeded environmental guideline values, suggesting potential health effects on humans and wildlife living near these dumping sites. The estimated intakes of dioxins via soil ingestion and dermal exposure for children were higher than those for adults, suggesting greater risk of dioxin exposure for children in dumping sites. To our knowledge, this is the first comprehensive study on PCDD/Fs contamination in open dumping sites of Asian developing countries. On the basis of the result of this study, we have addressed a new environmental issue that open dumping sites are potential sources of PCDD/Fs and related compounds, and dioxin contamination in dumping sites may become a key environmental problem in developing countries.     

Somatotropic axis and concentrate supplementation in grazing dairy cows of genetically diverse origin

Supplementing pasture-fed dairy cows with concentrates in early lactation was hypothesized to result in an earlier postpartum recoupling of the somatotropic axis in New Zealand (NZ)-type Holstein-Friesian dairy cows than in North American (NA)-type cows. To test this hypothesis, NA (n = 30) and NZ (n = 30) cows were allocated to 1 of 3 supplementation strategies (0, 3, or 6 kg of dry matter concentrate/d) for the first 12 wk of lactation in a completely randomized design and a 2 × 3 factorial arrangement. Production traits and characteristics of the somatotropic axis were studied at phenotypic, hormonal, and gene expression levels. Milk production and plasma metabolite concentrations were measured weekly, and liver was biopsied in wk 1, 4, 8, and 12 postcalving. North American cows produced more milk and displayed a larger degree of somatotropic axis uncoupling than did NZ cows. This was evident in strain differences in body condition score, blood growth hormone, and insulin-like growth factor-1 concentrations, and hepatic expression of growth hormone receptor-1a. No strain × diet interactions were observed for any characteristic of the somatotropic axis at either the blood metabolite or gene expression level; however, blood insulin concentrations during wk 7 to 11 postpartum increased with concentrate supplementation in NZ but not NA cows. These results demonstrate that feeding supplements does not result in an earlier recoupling of the somatotropic axis; however, the greater blood insulin concentrations with concentrate feeding in NZ cows from wk 7 may result in an earlier recoupling in this genetic strain, after the period investigated in this study. Further research is required to understand differences in insulin control between these genetic strains.     

Solar photolysis of CH2I2, CH2ICl, and CH2IBr in water, saltwater, and seawater

Ultraviolet-visible absorption spectroscopy and purge-and-trap GC-MS were used to determine the rates and products of the photodissociation of low concentrations of CH2I2, CH2IBr, and CH2ICl in water, saltwater (0.5 M NaCl), and seawater in natural sunlight. Photoproducts of these reactions include iodide (I-) and, in salt- and seawater environments, CH2XCl (where X = Cl, Br, or I). Thus, CH2ICl was produced during CH2I2 photolysis (with a molar yield of 35 +/- 20%), CH2BrCl from CH2IBr photolysis, and CH2Cl2 from CH2ICl photolysis (in lower yields of 6-10%). Formation of these chlorine-atom-substituted products may be via direct reaction of Cl- with either (A) the isopolyhalomethane photoisomer or associated ion pair (e.g., CH2I+-I-) or (B) the initially produced CH2I. photofragment. Estimated quantum yields for photodissociation were 0.62 +/- 0.09, 0.17 +/- 0.03, and 0.26 +/- 0.06 for CH2I2, CH2IBr, and CH2ICl, respectively, in 0.5 M NaCl, with only small differences from these values in water and seawater. The much higher quantum yield of CH2I2 photolysis compared to CH2IBr and CH2ICl photolysis may be explained by the higher yield of the isodiiodomethane photoisomer of CH2I2, resulting in reduced geminate recombination of the initially produced radical photofragments back to the parent molecule. We use a radiative transfer model with measured absorption cross-sections in saltwater to calculate seasonal values of CH2I2, CH2IBr, and CH2ICl photodissociation in surface seawater at midlatitudes (50 degrees N) and show that a significant proportion of CH2ICl in surface seawater may arise from CH2I2 photodecomposition. We also suggest that surface seawater photolysis of CH2I2 over an 8 h period may contribute up to approximately 10% of the surface seawater I- levels, with implications for the increased deposition of O3 to the surface ocean.     

The application of metaphor, analogy, and conceptual models in computer systems

People using computer systems naturally relate what they are experiencing to what they already know. This general cognitive process can be classified into metaphoric, analogical, and modelling processes. Metaphor, a term applied often to today's computer systems, is the process of representing the computer system with objects and events from a noncomputer domain, such as the popular desktop metaphor. Analogy is a comparison between objects or events that serve the same purpose but have different representations. Models are representations of the abstract conceptual structure of a computer system. This paper outlines the differences between these three processes and applies them to the computer domain. Implications for computer systems design are also discussed.