The use of polar organic compounds to estimate the contribution of domestic solid fuel combustion and biogenic sources to ambient levels of organic carbon and PM2.5 in Cork Harbour, Ireland

PM_2.5 samples collected at Cork Harbour, Ireland during summer, autumn, late autumn and winter, 2008-2009 were analyzed for polar organic compounds that are useful markers for aerosol source characterization. The determined compounds include tracers for biomass burning primary particles, fungal spores, markers for secondary organic aerosol (SOA) from isoprene, α-/β-pinene, and d-limonene. Seasonal and temporal variations and other characteristic features of the detected tracers are discussed in terms of aerosol sources and processes. The biogenic species were detected only during the summer period where the contributions of isoprene SOA and fungal spores to the PM_2.5 organic carbon (OC) were estimated to be 1.6% and 1% respectively. The biomass burning markers, and in particular levoglucosan, were present in all samples and attributed to the combustion of cellulose-containing fuels including wood, peat, bituminous and smokeless coal. The contribution of domestic solid fuel (DSF) burning to the measured OC mass concentration was estimated at 10.8, 50, 66.4 and 74.9% for summer, autumn, late autumn and winter periods, respectively, based on factors derived from a series of burning experiments on locally available fuels. Application of an alternative approach, namely principal component analysis-multiple linear regression (PCA-MLR), to the measured concentrations of the polar organic marker compounds used in conjunction with real-time air quality data provided similar trends and estimates for DSF combustion during all seasons except summer. This study clearly demonstrates that, despite the ban on the sale of bituminous coal in Cork and other large urban areas in Ireland, DSF combustion is still the major source of OC during autumn and winter periods and also makes a significant contribution to PM_2.5 levels. The developed marker approach for estimating the contribution of DSF combustion to ambient OC concentrations can, in principle, also be applied to other locations.     

Physician participation in TQM in geriatric medicine

BACKGROUND: Quality improvement (QI) approaches such as total quality management (TQM) and continuous quality improvement (CQI) have great potential for improving the care provided to older people. Geriatricians have the necessary experience and skills to initiate and lead these QI efforts. A national sample of practicing geriatricians was surveyed in 1998 regarding involvement in, satisfaction with, and insights regarding TQM processes in four care settings. RESULTS: Of 537 questionnaires returned in time for analysis, 497 were included for analysis after omitting questionnaires that were undeliverable or unusable (n = 25) and those from respondents who worked fewer than 20 hours per week (n = 15). More than one-third of the respondents (37.1%) reported no TQM activity at all. For the remainder, the primary site for TQM activity was the nursing home (33.0%), the hospital (22.5%), the office (11.4%), and the patient's home (3.7%). A majority of the respondents spent two hours per week or less on TQM projects. Planning an intervention and acting to maintain it in practice after its evaluation were the two stages of the improvement cycle these respondents engaged in most frequently. DISCUSSION: More geriatricians should be encouraged to participate in TQM training and in specific projects to improve systems of care for older people. Incentives to increase participation should be made available. Rapid-cycle improvement may fit better with physicians' culture of working for outcomes that have relatively short turnaround times.     

Differentiation of raw meat from phylogenically related species by enzyme-linked immunosorbent assay

A method, based on enzyme-linked immunosorbent assay (ELISA), has been developed for differentiating raw meat from closely related species of economic importance. By visual assessment 0·1% donkey in horse, 0·1% goat in sheep and 1% buffalo in beef may be detected. The technique is rapid and simple to perform and could be used in abattoirs and coldstores with results being available within 1 h.     

The effects of milk yield and stage of lactation on the partitioning of nutrients in lactating dairy cows

The objective of the experiment was to examine, using indirect calorimetry, the effects of milk yield and stage of lactation on the response in milk and body tissue energy, and heat production, to a reduction (decrement) in nutrient intake (assessed as metabolizable energy intake). Eight lactating dairy cows, four representing each of two stages of lactation [either mean initial days in milk (DIM) 158 (SD 6.1) or 414 (SD 51.1)] were used. Each cow underwent four 17-d periods incorporating two physiological states [number of mammary glands milked: either four (periods 1 and 2), or two (periods 3 and 4)], and two levels of metabolizable energy intake within each physiological state [either sufficient to meet requirements for zero tissue balance plus 10 MJ/d (periods 1 and 3)] or these allowances reduced by 20 MJ/d in the subsequent period (periods 2 and 4, respectively). Partitioning was calculated from the changes in metabolizable energy intake, milk energy, tissue energy, and heat production between DIM groups and between four and two gland milking (milk yield) components of the study. Partitioning of the changes in metabolizable energy intake was not influenced by DIM, but milk yield response was greater in the early lactation cows compared with the late group. Cows milked in four glands (higher milk yield) partitioned a significantly greater proportion of decremental changes in metabolizable energy intake to milk energy and less to tissue energy, than when milked in only two glands (lower milk yield).     

Performance and metabolic profile of dairy cows during a lactational and deliberately induced negative energy balance with subsequent realimentation

Homeorhetic and homeostatic controls in dairy cows are essential for adapting to alterations in physiological and environmental conditions. To study the different mechanisms during adaptation processes, effects of a deliberately induced negative energy balance (NEB) by feed restriction near 100 d in milk (DIM) on performance and metabolic measures were compared with lactation energy deficiency after parturition. Fifty multiparous cows were studied in 3 periods (1 = early lactation up to 12 wk postpartum; 2 = feed restriction for 3 wk beginning at 98 ± 7 DIM with a feed-restricted and control group; and 3 = a subsequent realimentation period for the feed-restricted group for 8 wk). In period 1, despite NEB in early lactation [−42 MJ of net energy for lactation (NE_L)/d, wk 1 to 3] up to wk 9, milk yield increased from 27.5 ± 0.7 kg to a maximum of 39.5 ± 0.8 kg (wk 6). For period 2, the NEB was induced by individual limitation of feed quantity and reduction of dietary energy density. Feed-restricted cows experienced a greater NEB (−63 MJ of NE_L/d) than did cows in early lactation. Feed-restricted cows in period 2 showed only a small decline in milk yield of −3.1 ± 1.1 kg and milk protein content of −0.2 ± 0.1% compared with control cows (30.5 ± 1.1 kg and 3.8 ± 0.1%, respectively). In feed-restricted cows (period 2), plasma glucose was lower (−0.2 ± 0.0 mmol/L) and nonesterified fatty acids higher (+0.1 ± 0.1 mmol/L) compared with control cows. Compared with the NEB in period 1, the decreases in body weight due to the deliberately induced NEB (period 2) were greater (56 ± 4 vs. 23 ± 3 kg), but decreases in body condition score (0.16 ± 0.03 vs. 0.34 ± 0.04) and muscle diameter (2.0 ± 0.4 vs. 3.5 ± 0.4 mm) were lesser. The changes in metabolic measures in period 2 were marginal compared with the adjustments directly after parturition in period 1. Despite the greater induced energy deficiency at 100 DIM than the early lactation NEB, the metabolic load experienced by the dairy cows was not as high as that observed in early lactation. The different effects of energy deficiency at the 2 stages in lactation show that metabolic problems in early lactating dairy cows are not due only to the NEB, but mainly to the specific metabolic regulation during this period.     

Effects of embryo culture on global pattern of gene expression in preimplantation mouse embryos

Culture of preimplantation embryos affects gene expression. The magnitude of the effect on the global pattern of gene expression, however, is not known. We compared global patterns of gene expression in blastocysts cultured from the one-cell stage in either Whitten's medium or KSOM + amino acids (KSOM/AA) with that of blastocysts that developed in vivo, using the Affymetrix MOE430A chip. The analysis revealed that expression of 114 genes was affected after culture in Whitten's medium, whereas only 29 genes were mis-expressed after culture in KSOM/AA. Expression Analysis Systematic Explorer was used to identify biological and molecular processes that are perturbed after culture and indicated that genes involved in protein synthesis, cell proliferation and transporter function were down-regulated after culture in Whitten's medium. A common set of genes involved in transporter function was also down-regulated after culture in KSOM/AA. These results provide insights as to why embryos develop better in KSOM/AA than in Whitten's medium, and highlight the power of microarray analysis to assess global patterns of gene expression.     

Electrochemical metal speciation analysis of chemically heterogeneous samples: the outstanding features of stripping chronopotentiometry at scanned deposition potential

The application of depletive stripping chronopotentiometry at scanned deposition potential (SSCP) to metal ion speciation analysis of chemically heterogeneous complex systems is described. In this electroanalytical stripping technique, metal which is accumulated in the electrode during the deposition step is quantitatively reoxidized during the detection step. SSCP is able to provide an unambiguous measure of heterogeneity that is not attainable by other nondepletive electroanalytical stripping techniques that measure only a proportion of the accumulated metal. SSCP data are not affected by the secondary interferences that plague conventional electrochemical techniques, that is, induced metal adsorption and insufficient ligand excess during stripping. Furthermore, the effect of heterogeneity, as manifested in flattening of the SSCP wave, can be distinguished from that of electrochemical irreversibility. Data are presented for complexation of Cu(II), Pb(II), and Cd(II) by several humic fractions: distinct heterogeneity differences are observed.     

Effects of oxytocin administration on oxytocin release and milk ejection

In experiment I, the effect of i.m. oxytocin (OT) injection (50 IU) on OT blood pattern was tested. Blood samples from 6 cows were collected for 2 h after OT injection either with or without milking. To test the effect of i.m. OT injection (50 IU) on milk ejection efficiency, intramammary pressure (IMP) was measured in 13 cows (experiment II). Milk ejection was induced by manual teat stimulation. After IMP increased and reached a plateau, OT was injected. In experiment III, the effect of chronic OT treatment on mammary gland sensitivity and endogenous OT release was tested. For 19 d, cows were i.m. injected at each milking with 50 IU OT (n = 13) or 5 mL of NaCl 0.9% (n = 14) 1 min before the start of udder preparation. To test mammary gland sensitivity, IMP recording was performed after a long (11 h, 7 OT cows, and 7 NaCl cows) and a short (3 h, 6 OT cows, and 7 NaCl cows) milking interval at d -1 and d 18. To test the effect of withdrawal of chronic i.m. treatment on OT release, blood sample collection was performed during evening milking at d 0 and d 19. Intramuscular oxytocin injection (experiment I) caused elevated OT blood levels observed at least for 2 h and showed an even more pronounced effect when milking was also performed. Intramuscular OT injection after teat stimulation (experiment II) caused additional milk ejection but only in 6 out of 13 cows. Withdrawal of chronic OT treatment (experiment III) did not reduce OT release during milking. However, ejection time was prolonged during OT infusion after a long milking interval. Ejection pressure tended to be lower after a short milking interval. It seems that the reduction of spontaneous milk removal after chronic OT treatment was due to reduced contractibility of myoepithelial cells in the mammary gland at a physiological range of OT concentrations.     

Identification of ABCA1 and ABCG1 in milk fat globules and mammary cells--implications for milk cholesterol secretion

The ATP-binding cassette (ABC) transporters ABCA1 and ABCG1 play an important role in cellular cholesterol homeostasis, but their function in mammary gland (MG) tissue remains elusive. A bovine MG model that allows repeated MG sampling in identical animals at different functional stages was used to test whether 1) ABCA1 and ABCG1 protein expression and subcellular localization in mammary epithelial cells (MEC) change during the pregnancy-lactation cycle, and 2) these 2 proteins were present in milk fat globules (MFG). Expression and localization in MEC were investigated in bovine MG tissues at the end of lactation, during the dry period (DP), and early lactation using immunohistochemical and immunofluorescence approaches. The presence of ABCA1 and ABCG1 in MFG isolated from fresh milk was determined by immunofluorescence. The ABCA1 protein expression in MEC, expressed as arbitrary units, was higher during the end of lactation (12.2 ± 0.24) and the DP (12.5 ± 0.22) as compared with during early lactation (10.2 ± 0.65). In contrast, no significant change in ABCG1 expression existed between the stages. Throughout the cycle, ABCA1 and ABCG1 were detected in the apical (41.9 ± 24.8 and 49.0 ± 4.96% of cows, respectively), basal (56.2 ± 28.1 and 54.6 ± 7.78% of cows, respectively), or entire cytoplasm (56.8 ± 13.4 and 61.6 ± 14.4% of cows, respectively) of MEC, or showed combined localization. Unlike ABCG1, ABCA1 was absent at the apical aspect of MEC during early lactation. Immunolabeling experiments revealed the presence of ABCA1 and ABCG1 in MFG membranes. Findings suggest a differential, functional stage-dependent role of ABCA1 and ABCG1 in cholesterol homeostasis of the MG epithelium. The presence of ABCA1 and ABCG1 in MFG membranes suggests that these proteins are involved in cholesterol exchange between MEC and alveolar milk.     

Improvement in regression of corn yield with plant height using relative data

BACKGROUND: The traditional approach of analyzing absolute variable data across multiple locations and/or years has drawbacks in precision agriculture. This study was conducted to evaluate the impacts of using relative yield and plant height data of corn (Zea mays L.) on the regression of yield with plant height using linear and exponential models in a nitrogen (N) rate field trial under four cropping systems. RESULTS: The use of relative yield to replace absolute yield frequently increased the determination coefficient (R²) values in the regression of yield with plant height on datasets combined across cropping systems or/and years. Relative yield and relative plant height sometimes further enhanced the R² values compared with relative yield and absolute plant height. All these improvements mostly occurred when the fit of the model was not strong with absolute yield and absolute plant height or relative yield and absolute plant height. The advantages of using relative data of yield or/and plant height were similar for the two regression models. CONCLUSION: The use of relative yield or relative data of both yield and plant height may be effective in improving the regression of corn yield with plant height across multiple cropping systems/locations and years in precision agriculture. Copyright © 2011 Society of Chemical Industry