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An instrument to measure the respiration rate of whole fruits and vegetables was designed and developed using a pressure variation method. The Motorola MPX-10-DP pressure transducer was used to monitor pressure changes due to respiratory activity. The operating procedures and calculations required to determine respiration rate (RR) in terms of CO2 produced, RR-CO2, and O2 consumed, RR-O2, with the respirometer were simple. The values of RR-CO2 and RR-O2 obtained by the pressure variation method were compared to changes in CO2 and O2 concentrations as determined by gas chromatography. The results showed no significant difference (0.05 level) between the two methods.  相似文献   
3.
The central questions of social development—from the roots of mother–infant attachment to the plasticity of aggressive behavior—pivot on the relations between genetic and ontogenetic sources of variance. It is proposed that (a) developmental, experiential, and microevolutionary processes typically collaborate, rather than compete, in achieving social adaptation; (b) social behavior patterns are mostly closed to modification in the course of development and across generations, but avenues of vulnerability exist in ontogeny and microevolution for dynamic, rapid, and reversible changes in key features; (c) a general avenue for change is delay or acceleration in the developmental onset of one or more features of the behavior pattern, which in turn modifies the functions and properties of the adaptive configuration; and (d) the features of social behavior that are open to rapid change in ontogeny should be open as well to rapid changes in microevolution, although different underlying processes may be involved. Empirical findings from the investigation of aggressive interactions are used to illustrate this proposal on the dual genesis and coincident adaptation of social behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
4.
A total of 119 Duroc × (Landrace × Yorkshire) commercial pigs were used to investigate the effect of growth rate (fast vs slow), sex (barrows vs gilts) and slaughter liveweight (107, 115 and 125 kg) on the fat characteristics of bellies. Backfat thickness increased with weight (P < 0.01). Fat firmness score was only affected by sex (P < 0.05), with gilts showing softer bellies than barrows. Fat from gilts and slow growing pigs showed a lower proportion of saturated fatty acids (SFA; P < 0.001 and P < 0.01, respectively), a higher proportion of linoleic fatty acid (C18:2 n-6; P < 0.01), a higher proportion of total polyunsaturated fatty acids (PUFA; P < 0.001 and P < 0.01, respectively), and an increased iodine value (P < 0.001). Consequently, the fat from these bellies had higher PUFA:SFA ratios (P < 0.001) and n-6:n-3 ratios (P < 0.01 and P < 0.001, respectively) than that from the bellies of barrows and fast growing pigs. The belly fat from barrows and fast growing pigs had higher stearic fatty acid (C18:0; P < 0.01) and SFA proportions (P < 0.001 and P < 0.01, respectively) than that from gilts and slow growing pigs. The belly fat from gilts and slow growing pigs would better meet the health requirements of consumers, but it is more prone to rancidity during storage leading to a potentially reduced bacon shelf-life.  相似文献   
5.
Higher osmium concentrations and lower 187Os/188Os ratios in sediments from urban areas have been linked to anthropogenic osmium sources. Automobile catalytic converters that use platinum group metals (PGM) are a potential source for this Os pollution. We present the first direct Os concentrations and isotopic measurements of catalytic converters for major automobile brands to test the assumption that car catalysts release Os with a distinct signature in the environment. The analysis of four new catalytic converters yields similar low 187Os/188Os ratios (0.1-0.2), suggesting a similar source for the PGM. The Os concentrations measured are in the ppt range (6-228 ppt). From our results, the osmium contribution of the car catalysts to the environment through attrition (wearing and grinding down of the catalyst by friction) is predicted to be low, <0.2 pg Os/m2/year in highly urbanized environment. We show that Os loss from catalysts as volatile OsO4 is important at car catalyst operating temperatures. Moreover, we estimate that car catalysts may be responsible for up to approximately 120 pg Os/m2 deposited per year in urban areas and that part of it may be exported to sedimentary sinks. Car catalytic converters are thus an important anthropogenic osmium source in densely populated areas. The NIST car catalyst standard (SRM-2557, made from recycled used catalysts) yields higher concentrations (up to 721 ppt Os) and a more radiogenic isotopic composition (approximately 0.38), perhaps indicative of Os contamination during its preparation.  相似文献   
6.
The accepted decompression methods of chronic pancreatitis are the longitudinal pancreaticogastrostomy and the conventional pancreaticojejunostomy. The aim of the present study was to estimate the effect of these types of drainage operations on gastric acidity and to evaluate the clinical results. Between Jan. 1992 to 1996 56 patients with chronic pancreatitis were selected into the investigation who were operated in our clinic. A 24 hour gastric monitoring was taken on every patient before and 6 weeks after the operation. Following a complete postoperative check up we found that both types of operations are effective for pain relief (71%). Retrospectively 83% of the patients had no digestive problems due to pancreatic enzyme substitution. According to our statistical evaluation of 24 hour gastric pH monitoring test no alteration was detected in gastric pH in both groups pre- and postoperatively. On the basis of pH measuring and evaluated data we consider that pancreaticogastrostomy is a good operation choice to relieve intractable pain in selected patients with chronic pancreatitis associated with duct dilatation.  相似文献   
7.
Studied social networks and aggressive behavior in school in 2 cohorts of boys and girls in the 4th and 7th grades (N?=?695). Measures of social networks yielded convergent findings. Highly aggressive subjects (both boys and girls) did not differ from matched control subjects in terms of social cluster membership or in being isolated or rejected within the social network. Peer cluster analysis and reciprocal "best friend" selections indicated that aggressive subjects tended to affiliate with aggressive peers. Even though highly aggressive children and adolescents were less popular than control subjects in the social network at large, they were equally often identified as being nuclear members of social clusters. Aggressive subjects did not differ from matched control subjects in the number of times they were named by peers as "best friend," nor did the two groups differ in the probability of having friendship choices reciprocated by peers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
8.
A beef processing strategy for improving energy and labour efficiencies, modified hot processing (MHP), was developed in a research abattoir. The work reported herein investigated carcass chilling rates and electrical energy usage in the chilling of carcasses that were processed using this approach. The MHP procedure removes the lower value cuts from the dressed carcass along with associated bone and fat. The remaining high value meat (posterior carcass quarter) is chilled in the usual manner, while the low value cuts are immediately processed (e.g. reduced into pre-blended, salted, chilled meat for emulsion-type products; rendered; directly processed as fresh, hot-boned meat, etc.). Carcasses prepared by the MHP method were dissected to quantify the amounts of lean meat, separable fat and bone removed in the procedure. These data were used with a simple model to predict the amount of chilling energy that could be saved by applying MHP prior to chilling. Electrical power to operate a blast chilling facility containing carcasses that had been processed either by conventional processing or by MHP methods was monitored and recorded, and the resulting data was used to confirm the model result. The MHP procedure reduced the refrigeration load for beef chilling by as much as 51% (P < 0·05). The amount of chilling energy to be saved would depend upon the methods employed to further process the low value tissues, and was calculated to be no less than 7%. The time for the reduced MHP carcass quarters to chill to 10°C at the fat-muscle interface of the longissimus dorsi muscle (12/13 rib) was shorter for MHP carcasses than for conventional carcasses (5·77 h vs 7·08 h, respectively) (P < 0·05). However, the times to chill the deep hip location of MHP hind quarters and conventional beef sides were not significantly different (P < 0·05).  相似文献   
9.
On the basis of the overlap integral method, an approximate analytical model is derived to estimate the coupled optical power between axisymmetric Gaussian beams when transverse, axial, and angular misalignments simultaneously exist in three dimensions. Seven optical properties are derived from a detailed analysis of the model. Because the model is an approximate analytical solution to the overlap integral method, the existence of each property is also investigated by a numerical solution. Results show that all seven properties are intrinsic to the optical coupling phenomenon between Gaussian beams. Because numerous single-mode device-to-fiber coupling systems can be well described by use of Gaussian beams, the seven properties provide a solid basis to develop model-based algorithms for single-mode device-to-fiber alignment automation.  相似文献   
10.
Physico-chemical characteristics of veal from 30 calves allotted to five different rations with respect to iron bioavailability were evaluated at packaging and after 2 and 4 weeks of storage under both 100% CO(2) and 100% N(2). The five diets were 'Milk', 'Grain', 'Mix' (combination of Milk and Grain) and 'Mix + EDTA' and 'Grain + EDTA' where 15 mg EDTA were added per mg Fe in the feed concentrate. Diet EDTA was generally more influential on veal quality than storage treatments. The chelator caused an unexpected pH drop in veal stored four weeks irrespective of storage conditions (p ≤ 0.05). However, the colour, texture and flavour of meat from animals fed EDTA in the Grain- and Mix-ration was equivalent to that of Milk-fed veal (p ≤ 0.05). The EDTA treatments also improved the appearance of veal under anoxic atmospheres. Upon storage however, the chelator increased veal drip losses (p ≤ 0.05) and also cooking losses from Grain-fed calves (p ≤ 0.05). Packaging under CO(2) decreased pH (p ≤ 0.05) and increased drip losses (p ≤ 0.05) but did not alter other physico-chemical parameters. Dietary treatments had no effect on shear forces (p > 0.05) which decreased after two weeks in storage (p ≤ 0.05) independent of gas atmospheres. Overall, the quality characteristics of pale veal were obtained following addition of EDTA in Grain- and Mix-fed animals and were maintained in storage. This approach looks promising for the veal industry but warrants further research.  相似文献   
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