Relationship between residual feed intake and digestibility for lactating Holstein cows fed high and low starch diets

We determined if differences in digestibility among cows explained variation in residual feed intake (RFI) in 4 crossover design experiments. Lactating Holstein cows (n = 109; 120 ± 30 d in milk; mean ± SD) were fed diets high (HS) or low (LS) in starch. The HS diets were 30% (±1.8%) starch and 27% (±1.2%) neutral detergent fiber (NDF); LS diets were 14% (±2.2%) starch and 40% (±5.3%) NDF. Each experiment consisted of two 28-d treatment periods, with apparent total-tract digestibility measured using indigestible NDF as an internal marker during the last 5 d of each period. Individual cow dry matter (DM) intake and milk yield were recorded daily, body weight was measured 3 to 5 times per week, and milk components were analyzed 2 d/wk. Individual DM intake was regressed on milk energy output, metabolic body weight, body energy gain, and fixed effects of parity, experiment, cohort (a group of cows that received treatments in the same sequence) nested within experiment, and diet nested within cohort and experiment, with the residual being RFI. High RFI cows ate more than expected and were deemed less efficient. Residual feed intake correlated negatively with digestibility of starch for both HS (r = ?0.31) and LS (r = ?0.23) diets, and with digestibilities of DM (r = ?0.30) and NDF (r = ?0.23) for LS diets but was not correlated with DM or NDF digestibility for HS diets. For each cohort within an experiment, cows were classified as high RFI (HRFI; >0.5 SD), medium RFI (MRFI; ±0.5 SD), and low RFI (LRFI; <?0.5 SD). Digestibility of DM was similar (~66%) among HRFI and LRFI for HS diets but greater for LRFI when fed LS diets (64 vs. 62%). For LS diets, digestibility of DM could account for up to 31% of the differences among HRFI and LRFI for apparent diet energy density, as determined from individual cow performance, indicating that digestibility explains some of the between-animal differences for the ability to convert gross energy into net energy. Some of the differences in digestibility between HRFI and LRFI were expected because cows with high RFI eat at a greater multiple of maintenance, and greater intake is associated with increased passage rate and digestibility depression. Based on these data, we conclude that a cow’s digestive ability explains none of the variation in RFI for cows eating high starch diets but 9 to 31% of the variation in RFI when cows are fed low starch diets. Perhaps differences in other metabolic processes, such as tissue turnover, heat production, or others related to maintenance, can account for more variation in RFI than digestibility.     

Catalytic Production of 1-Octadecanol from Octadecanoic Acid by Hydrotreating in a Plug Flow Reactor

1-Octadecanol (stearic alcohol) has uses ranging from lubricants to perfumes. The production of 1-octadecanol from octadecanoic acid (stearic acid) was investigated in a liquid-phase trickle-bed reactor by hydrogenating octadecanoic acid using a Ni/Co/Mo sulfide catalyst. The primary reactions occurring in the reactor were the desired conversion of octadecanoic acid to 1-octadecanol and the subsequent undesired conversion of 1-octadecanol to octadecane. A model was developed to predict these two reactions. The model found to be most useful for this system was a series–parallel reaction first order in octadecanoic acid and 1-octadecanol and pseudo-zero order in hydrogen for both reactions. The activation energies of the first and second reactions were 63.7.8 and 45.6 kJ/mol, respectively. From these values, the conversion of octadecanoic acid and the selectivity to the desired product as functions of temperature, space velocity, and inlet octadecanoic acid concentration were estimated. The model predicts the maximum productivity of 1-octadecanol occurs at higher temperatures with short residence times. Parametric plots show productivity to be ≥0.48 g 1-octadecanol/g octadecanoic acid at 566 °F and a 0.1 h residence time.     

Short-term exercise enhances insulin-stimulated GLUT-4 translocation and glucose transport in adipose cells

This investigation examined the effects of short-term exercise training on insulin-stimulated GLUT-4 glucose transporter translocation and glucose transport activity in rat adipose cells. Male Wistar rats were randomly assigned to a sedentary (Sed) or swim training group (Sw, 4 days; final 3 days: 2 x 3 h/day). Adipose cell size decreased significantly but minimally (approximately 20%), whereas total GLUT-4 increased by 30% in Sw vs. Sed rats. Basal 3-O-methyl-D-[14C]glucose transport was reduced by 62%, whereas maximally insulin-stimulated (MIS) glucose transport was increased by 36% in Sw vs. Sed rats. MIS cell surface GLUT-4 photolabeling was 44% higher in the Sw vs. Sed animals, similar to the increases observed in MIS glucose transport activity and total GLUT-4. These results suggest that increases in total GLUT-4 and GLUT-4 translocation to the cell surface contribute to the increase in MIS glucose transport with short-term exercise training. In addition, the results suggest that the exercise training-induced adaptations in glucose transport occur more rapidly than previously thought and with minimal changes in adipose cell size.     

Choctaw Eco-Industrial Park: an ecological approach to industrial land-use planning and design

This project investigates the concepts of industrial ecology and eco-industrial parks and applies those concepts to the redesign of an existing industrial park in Choctaw, OK. The opportunity for developing an eco-industrial park on this site comes from the availability of waste water for non-potable water needs, and the abundance of waste tires as raw materials for products to drive a new set of industrial partnerships. These industrial partnerships include the City of Choctaw Waste Water Treatment Plant, a tire shredding company, a tire pyrolysis company, a hydroponics industry, a hard rubber tire manufacturer, a screen printer, a plastics manufacturer, a toner manufacturer, and a toner cartridge manufacturer. The nature of this relationship and the design of the eco-industrial park is contained within this report. The result of this investigation is a new, common sense, approach to industrial land use that combines economic growth and environmental protection.     

Conditioning leisure time physical activity and cardiorespiratory fitness in sociodemographic groups of middle-ages men in eastern Finland

In the decade of the 1990's the human aspect has once again taken center stage in the design and operation of commercial aircraft. As occupation health and safety has gained importance in society in general, it has gained even more importance in the design an operation of commercial aircraft. In aircraft design today, the man-machine interface is considered in every task of the human workload. The discipline of ergonomics truly impacts each phase of product or tool design. At IPTN, the ergonomics effort is principally being applied to the design of the cockpit, cabin and cargo compartment of the N250. The ergonomists at IPTN are keenly aware that there would be a conflict between the user and his working environment without proper attention to the human considerations in the design is left for ergonomists and innovative programs like IPTN's participatory approach, to ensure that the human aspect is optimized in the man-machine interface.     

Factors regulating insulin-like growth factor-binding protein-3 binding, processing, and potentiation of insulin-like growth factor action

In this study, we investigated the effects of various biochemical and pharmacological agents on insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) cell binding and action in cultured bovine fibroblasts. When cells were preincubated for 48 h with 50 nM recombinant human (rh) IGFBP-3, IGF-I-stimulated [3H]aminoisobutyric acid ([125H]AIB) uptake was enhanced 2- to 3-fold. The addition of cytoskeletal disrupting agents during the preincubation with rhIGFBP-3 did not affect IGFBP-3 potentiation of IGF-I action, nor did a variety of serine, aspartate, and metalloproteinase inhibitors. On the other hand, ammonium chloride and chloroquine, weak bases that neutralize the pH of acidic cell compartments, blocked IGFBP-3 potentiation of IGF-I-stimulated [3H]AIB uptake. Chloroquine and ammonium chloride had no effect alone and did not inhibit IGF-I receptor binding or action in the absence of rhIGFBP-3. Bafilomycin A, a specific inhibitor of ATP-dependent hydrogen ion pumps, also inhibited IGFBP-3 potentiation of IGF-I-stimulated [3H]AIB uptake. Competitive [125I]IGF-I binding and affinity cross-linking experiments suggested structure/function changes in cell-bound IGFBP-3 that were altered in the presence of chloroquine and bafilomycin. Heparin markedly decreased initial IGFBP-3 cell adherence, but could not promote dissociation of IGFBP-3 from cells after the 48-h preincubation. Moreover, heparin did not inhibit IGFBP-3 potentiation of IGF-I action. In summary, these data indicate that IGFBP-3 undergoes specific pH-dependent structural and/or environmental modifications that mediate the enhancing effect of IGFBP-3 on IGF-I action in bovine fibroblasts. They also suggest that IGFBP-3 binding to heparin-like molecules on the cell surface is not directly involved in this process.     

Atrioventricular junctional tissue. Discrepancy between histological and electrophysiological characteristics

BACKGROUND: Previous work has demonstrated that cells with AV nodal-type action potentials are not confined to Koch's triangle but may extend along the AV orifices. The aim of this study was to examine the histological and electrophysiological characteristics of this tissue. METHODS AND RESULTS: Studies were performed in isolated, blood-perfused dog and pig hearts. Microelectrode recordings revealed cells with nodal-type action potentials around the tricuspid and mitral valve rings. These cells were found within 1 to 2 mm of the valve annuli. A zone of cells with intermediate action potentials, approximately 1 cm wide, separated cells with nodal-type action potentials from cells with atrial-type action potentials in the body of the atria. In cells with nodal-type action potentials, adenosine caused a reduction in action potential amplitude (49 +/- 2 versus 33 +/- 2 mV, mean +/- SE; P < .001), upstroke velocity (2.5 +/- 0.2 versus 2.0 +/- 0.2 V/s, P < .05), and duration (150 +/- 4 versus 96 +/- 8 ms, P < .001). The light microscopic appearance of AV junctional cells was similar to that of myocytes in the body of the atrium. A polyclonal antibody raised against connexin-43 bound to atrial and ventricular tissue but not to the AV junctional tissue or AV nodal region. The absence of connexin-43 correlated with the sites of cells with nodal-like action potentials. With pacing techniques, the AV junctional tissue in the region of the posterior AV nodal approaches could be electrically dissociated from atrial, AV nodal, and ventricular tissue. AV nodal echoes were induced with ventricular pacing in three dog hearts. In each case, retrograde conduction was through the slow pathway, and anterograde conduction was through the fast pathway. During echoes, activation of AV junctional cells preceded atrial activation during retrograde slow pathway conduction, but these cells were not activated during anterograde fast pathway conduction. CONCLUSIONS: AV junctional cells around both annuli are histologically similar to atrial cells but resemble nodal cells in their cellular electrophysiology, response to adenosine, and lack of connexin-43. The light microscopic appearance of AV junctional cells is a poor guide to their action potential characteristics. The AV junctional cells in the posterior AV nodal approaches appear to participate in slow pathway conduction. These cells may be the substrate of the slow "AV nodal" pathway.     

Stable transduction of recombinant adeno-associated virus into hematopoietic stem cells from normal and sickle cell patients

The effectiveness of a health education programme for prevention of alcohol abuse and tobacco smoking among adolescents was assessed by an intervention study with a non-randomized control group. The study was carried out among 7th-9th grade school students in a Local Health Unit of the Brescia province, North Italy. Students were enrolled in either the intervention or the control group, based on the participation of their teachers to the educational programme. A total of 428 students were involved in the programme representing the intervention group, and 658 students not involved in the programme formed the control group. The health education programme included the prevention of alcohol abuse in the first school year (1989-90) and the prevention of tobacco smoking in the second year (1990-91). Each part of the programme included a series of lessons taken by the teachers for about 20 hours. Alcohol use and smoking habits, knowledge about, and attitudes toward alcohol and tobacco use of the students have been assessed by anonymous questionnaires. The questionnaires have been administered during school time at the beginning and the end of each school year, giving a total of 6 questionnaires, from Q1 to Q6. All the questionnaires included the same questions on alcohol and tobacco use, knowledge and attitudes. Of the 1086 students who attended the 7th grade in the year 1989-90, 428 were enrolled as intervention group and 658 as control group. As regards alcohol, the following findings were observed: 1. no difference was found in the percentages of students drinking at least one glass of wine or beer daily between the 2 groups at Q6; 2. no substantial change in the percentage of students aware of the health risks of alcohol abuse from Q1 to Q6 was observed. As regards tobacco smoking, the results of the study showed: 1. no difference between the 2 groups was found at Q6 as regards the proportion of students who smoked one or more cigarettes a month; 2. the percentages of students planning to smoke in the future were similar in the 2 groups in Q6; 3.the percentage of students with a high score on the health consequences of smoking was higher in the intervention than the control group at Q4, but again no difference between the groups was evident at Q6. In conclusion, the health education programme seemed to be unsuccessful in modifying behaviors and attitudes regarding alcohol and tobacco use during the 3-year follow-up.     

Characteristics of the histamine release from hamster cheek pouch mast cells stimulated by lectins from Brazilian beans and concanavalin A

We have characterized the histamine releasing effects of lectins extracted from Brazilian beans, in comparison to concanavalin A, in hamster cheek pouch cell suspensions containing mast cells. The lectins from Dioclea virgata, Canavalia brasiliensis, and Dioclea rostrata induce histamine release in a similar manner to concanavalin A, but appear to differ in potency and efficacy. The effects depended on the temperature, pH, and metabolic energy, demonstrating the non-cytotoxic nature of the histamine release. It is suggested that the lectins studied act by the same mechanism as concanavalin A (interacting with sugars in the antibodies bound to the mast cells), since high concentrations of glucose inhibit the histamine release. The lectins at high concentrations quench the histamine release. This suppression is reversed by increasing calcium concentration, suggesting that the lectins bind to the calcium that is essential for the secretion, thereby confirming and extending our previous data using the lectin from Dioclea virgata in rat peritoneal mast cells.     

Protein-reactive metabolites of carbamazepine in mouse liver microsomes

The character of reactive metabolites formed from carbamazepine (CBZ) was sought in incubations of [14C]CBZ in hepatic microsomes prepared from adult female mice of a strain (SWV/Fnn) susceptible to CBZ-induced teratogenicity. The formation of radio-labeled protein adducts was used as an index of reactive metabolite exposure. A dependence on cytochrome P450 was shown by a requirement for NADPH and inhibition by carbon monoxide, 1-aminobenzotriazole, piperonyl butoxide, and stiripentol. The addition of ascorbic acid, caffeic acid, N-acetylcysteine, and glutathione decreased the rate of binding of the radiolabel from [14C]CBZ to microsomal protein by more than 50%. The addition of glutathione transferases diminished protein adduct formation beyond that seen with glutathione alone. Evidence for the formation of an arene oxide was sought through the use of inhibitors of epoxide hydrolases, including cyclohexene oxide, chalcone oxides (with the addition of cytosol as appropriate), and by the addition of recombinant human soluble and microsomal epoxide hydrolases and recombinant rat microsomal epoxide hydrolase. The microsomal epoxide hydrolases decreased the velocity of 14C-labeled protein adduct formation by approximately 23%, whereas inhibitors had no effect, most likely because of the low native activity of microsomal epoxide hydrolase in mice. Both DT-diaphorase and catechol-O-methyltransferase diminished 14C-labeled protein adduct formation by 54% and 45%, respectively. The data suggest that the major reactive metabolites formed from CBZ by adult female SWV/Fnn liver microsomes are quinones and arene oxides.