Showing papers by "Oklahoma State University–Stillwater published in 1992"
TL;DR: It is suggested that lec cotyledons are partially transformed into leaves and that the wild-type gene (LEC) functions to activate a wide range of embryo-specific pathways in higher plants.
Abstract: Cotyledons are specialized leaves produced during plant embryogenesis. Cotyledons and leaves typically differ in morphology, ultrastructure, and patterns of gene expression. The leafy cotyledon (Iec) mutant of Arabidopsis thaliana fails to maintain this distinction between embryonic and vegetative patterns of plant development. Mutant embryos are phenotypically abnormal, occasionally viviparous, and intolerant of desiccation. Mutant cotyledons produce trichomes characteristic of leaves, lack embryo-specific protein bodies, and exhibit a vascular pattern intermediate between that of leaves and cotyledons. These results suggest that lec cotyledons are partially transformed into leaves and that the wild-type gene (LEC) functions to activate a wide range of embryo-specific pathways in higher plants.
259 citations
TL;DR: Taste panel tenderness, amount of perceived connective tissue, and shear force values peaked at 112 d and were slightly less desirable for cattle fed longer than 112 d (quadratic term, P less than .01); postmortem muscle temperature at 2.5 h was the chilling time most highly correlated with tenderness values among untrimmed sides.
Abstract: Angus x Hereford steers (n = 48) similar in frame size and in muscle thickness were allotted to eight groups (n = 6) of similar mean live weight for serial slaughter at 28-d intervals (0 to 196 d). Except for d-0 steers, which served as grass-fed controls, all steers were fed a high-concentrate diet during the finishing period. Upon slaughter, one side of each carcass was trimmed of subcutaneous fat in the wholesale rib region. Postmortem longissimus muscle (LM) temperature was monitored for each side during the 24-h chilling period. After quality and yield grade data were collected, rib steaks were removed and aged (7 d) and sensory traits of the steaks were evaluated. Most carcass grade traits increased linearly (P less than .01) with days on feed, whereas most sensory panel variables and marbling increased curvilinearly (P less than .05). Generally, after 56 d on feed, carcasses chilled at slower rates (P less than .05) with increased days fed. Taste panel tenderness, amount of perceived connective tissue, and shear force values peaked at 112 d and were slightly less desirable for cattle fed longer than 112 d (quadratic term, P less than .01). Postmortem muscle temperature at 2.5 h was the chilling time most highly correlated with tenderness values among untrimmed sides. Correlations for shear force with 2.5-h LM temperature, marbling score, days fed, fat thickness, and carcass weight were -.63, -.61, -.56, -.55, and -.53, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
211 citations
TL;DR: Even though absolute values may be imprecise and inaccurate, marker-based estimates usually provide reliable information about the direction and extent of kinetic changes induced by treatments, and inherent variation may be small relative to other sources of variation.
205 citations
TL;DR: The results show that the simple neural net model tested on this set of time series could forecast about as well as the Box-Jenkins automatic forecasting expert system.
Abstract: Among the various potential applications of neural networks, forecasting is considered to be a major application. Several researchers have reported their experiences with the use of neural networks in forecasting, and the evidence is inconclusive. This paper presents the results of a forecasting competition between a neural network model and a Box-Jenkins automatic forecasting expert system. Seventy-five series, a subset of data series which have been used for comparison of various forecasting techniques, were analysed using the Box-Jenkins approach and a neural network implementation. The results show that the simple neural net model tested on this set of time series could forecast about as well as the Box-Jenkins forecasting system.
190 citations
TL;DR: In this paper, the need for a preliminary variance test and the special emphasis given to the equal variance assumption are questioned in the two-sample means test, and conclusions can be easily used in the classroom to teach the two sample means test.
Abstract: In the two-sample means test, the need for a preliminary variance test and the special emphasis given to the equal variance assumption are questioned. The conclusions can be easily used in the classroom to teach the two sample means test.
185 citations
TL;DR: Results indicates that immunomodulation of the host during tick feeding facilitates engorgement and pathogen transmission and reductions in cytokine levels would suppress immune responses directed toward immunogens introduced into theHost during the course of tick feeding.
Abstract: Ixodid tick infestation induces host acquired resistance, which involves immunoglobulin cell-mediated and complement-dependent effector pathways. Ticks have developed countermeasures to modulate host antiarthropod responses. Ixodid-mediated host immunomodulation results in vitro in reduced responsiveness to T-lymphocyte mitogens for cells obtained from infested hosts and impaired antibody responses to a thymic dependent antigen. Salivary gland extracts from days 0–9 of engorgement from unmated, female Dermacentor andersoni Stiles suppressed lymphocyte proliferative responses (LPS) to the T-cell mitogen Con A up to 68.4%, whereas responsiveness to E. coli LPS was enhanced. Cytokines assessed in this study included interleukin-1, IL-1, and tumor necrosis factor (TNF) alpha produced by macrophages, and interleukin-2, IL-2, and gamma interferon (IFN-G) secreted by T-lymphocytes. Salivary gland extracts prepared from tissues obtained on days 0–5 of engorgement suppressed IL-1 elaboration from 89.8% on day 0 through 37.5% on day 6. Levels of TNF were reduced from 40.7 to 94.6% throughout the course of the study. Production of IL-2 was suppressed by 14.1–31.9%, and IFN-G was reduced by 8.7–57.0%. Reduced IL-1 levels during the early phases of feeding indicated reduced host ability to activate T-lymphocytes and provide costimulatory, differentiation, and development signals for B-cells. Both IL-1 and TNF are endogenous pyrogens and activate polymorphonuclear leukocytes. Activities of TNF and IFN-G include antiviral properties and induction of expression of class I and II major histocompatibility complex molecules, which are critical components in the recognition of antigen by T-lymphocytes. The autocrine role of IL-2 in proliferation of T-lymphocytes is central to the development of immune reactivity involving T-cell regulation or effector functions or both. Reductions in cytokine levels would suppress immune responses directed toward immunogens introduced into the host during the course of tick feeding. These results indicates that immunomodulation of the host during tick feeding facilitates engorgement and pathogen transmission.
166 citations
TL;DR: In this paper, a knowledge-based design approach that minimizes the total capital cost at a preselected reliability level is presented, quantified by the loss of power supply probability.
Abstract: Integrated renewable systems utilize two or more renewable energy resources and end-use technologies to supply a variety of energy needs, often in a stand-alone mode. A knowledge-based design approach that minimizes the total capital cost at a preselected reliability level is presented. The reliability level is quantified by the loss of power supply probability. The procedure includes some resource-need matching based on economics, the quality of energy needed, and the characteristics of the resource. A detailed example is presented and discussed to illustrate the usefulness of the design approach. >
143 citations
TL;DR: In this paper, a multibank address assignment for an arbitrary fixed radix fast Fourier transform (FFT) algorithm suitable for high-speed single-chip implementation is developed, which is memory-bank conflict-free to allow simultaneous access to all the data needed for calculation of each of the radix r butterflies as they occur in the algorithm.
Abstract: A multibank memory address assignment for an arbitrary fixed radix fast Fourier transform (FFT) algorithm suitable for high-speed single-chip implementation is developed. The memory assignment is 'in place' to minimize memory size and is memory-bank conflict-free to allow simultaneous access to all the data needed for calculation of each of the radix r butterflies as they occur in the algorithm. Address generation for table lookup of twiddle factors is also included. The data and twiddle factor address generation hardware is shown to have small size and high speed. >
131 citations
TL;DR: Reduced stomatal aperture and Calvin cycle activity, but not electron transport/photophosphorylation, appeared to be major reasons for drought stress-induced inhibition of A(350), which is of theoretical as well as practical interest.
Abstract: It is of theoretical as well as practical interest to identify the components of the photosynthetic machinery that govern variability in photosynthesis rate (A) and water-use efficiency (WUE), and to define the extent by which the component processes limit A and WUE during developing water-deficit stress. For that purpose, leaf exchange of CO2 and H2O was determined in two growth-chamber-grown wheat cultivars (Triticum aestivum L. cv TAM W-101 and cv Sturdy), and the capacity of A was determined and broken down into carboxylation efficiency (c.e.), light- and CO2-saturated A, and stomatal conductance (gs) components. The limitations on A measured at ambient CO2 concentration (A350) were estimated. No cultivar difference was observed when A350 was plotted versus leaf water potential (Ψw). Light- and CO2-saturated A, c.e., and gs decreased with decreasing leaf Ψw, but of the corresponding photosynthesis limitations only those caused by insufficient c.e. and gs increased. Thus, reduced stomatal aperture and Calvin cycle activity, but not electron transport/photophosphorylation, appeared to be major reasons for drought stress-induced inhibition of A350. WUE measured as A350/gs first increased with stomatal closure down to a gs of about 0.25 mol H2O m−2 s−1 (Ψw = −1.6 MPa). However, it was predicted that A350/gs would decrease with more severe stress due to inhibition of c.e.
128 citations
TL;DR: It is shown that the lattice will evolve from a crystalline state in equilibrium to a polycrystalline state if subjected to a very low shear; and as the shear is increased, partial order is reestablished with the apparent appearance of sliding layer flow.
Abstract: Small angle neutron scattering experiments were carried out on a charged stabilized dense colloidal suspension to observe changes in lattice structure as a function of shear rate. It is shown that (1) the lattice will evolve from a crystalline state in equilibrium to a polycrystalline state if subjected to a very low shear; and (2) as the shear is increased, partial order is reestablished with the apparent appearance of sliding layer flow. The transitions are reversible. The first transition occurs when the dynamic yield stress is exceeded; the second is discontinuous and is associated with an anomalous flow region in which the stress decreases with increasing shear rate.
118 citations
Journal Article•
TL;DR: The development and transmission of A marginale was studied in Dermacentor andersoni males as mentioned in this paper, which was found in midgut epithelial cells on the sixth day of feeding on infected calves, with the highest density of colonies found in gut cells between feeding periods.
Abstract: The development and transmission of Anaplasma marginale was studied in Dermacentor andersoni males. Laboratory-reared male D andersoni were allowed to feed for 7 days on a calf with ascending A marginale parasitemia. The ticks were then held in a humidity chamber for 7 days before being placed on 2 susceptible calves. Anaplasmosis developed in the calves after incubation periods of 24 and 26 days. Gut and salivary glands were collected from ticks on each day of the 23-day experiment and examined with light and electron microscopy. Colonies of A marginale were first observed in midgut epithelial cells on the sixth day of feeding on infected calves, with the highest density of colonies found in gut cells while ticks were between feeding periods. The first colonies contained 1 large dense organism that subsequently gave rise to many reticulated organisms. Initially, these smaller organisms were electron-lucent and then became electron-dense. On the fifth day after ticks were transferred to susceptible calves for feeding, A marginale colonies were found in muscle cells on the hemocoel side of the gut basement membrane. A final site for development of A marginale was the salivary glands. Colonies were first seen in acinar cells on the first day that ticks fed on susceptible calves, with the highest percentage of infected host cells observed on days 7 to 9 of that feeding. Organisms within these colonies were initially electron-lucent, but became electron-dense.
TL;DR: Among the diffusion-jump, extended generalized autoregressive conditional heteroskedasticity (GARCH), and deterministic chaos processes, a GARCH process with residuals following a student distribution is the most likely as discussed by the authors.
Abstract: Daily cash price changes are not normally distributed. Their empirical distributions have fat tails and most are skewed. In addition, they are not independent. Among the diffusion-jump, extended generalized autoregressive conditional heteroskedasticity (GARCH), and deterministic chaos processes, a GARCH process with residuals following a student distribution is the most likely. Our GARCH model reduces leptokurtosis, removes nonlinear dependence, and provides a considerable improvement over the i.i.d. normal model. The GARCH process is not well calibrated because it cannot explain all the observed nonnormality, but it does yield asymptotically valid hypothesis tests.
TL;DR: The hypothesis that testing in either environment alone (drought stressed or irrigated) may not be most effective for increasing either mean productivity or yield under drought stress is supported.
Abstract: Wheat (Triticum aestivum L.) cultivars grown in the southern Great Plains of the U.S.A. are exposed to a wide range of moisture conditions due to large fluctuations in the amount and frequency of rainfall. Yield stability under those conditions is therefore a desirable trait for wheat breeders. Our primary objective was to quantify various genetic parameters for grain production in drought-stressed and irrigated environments. We also attempted to predict and measure yield responses when selection is practiced in either drought-stressed or irrigated environments, or both. Seventy F2-derived lines from the cross, TAM W-101/Sturdy, were evaluated at Goodwell, OK, under irrigated and naturally drought-stressed conditions in 1987 and 1988. Genetic variance and heritability estimates were higher in the irrigated environment than in the drought-stressed environment. The genetic correlation coefficient for yields in the two environments was 0.20±0.16, indicating that selection of widely adapted genotypes requires testing in both environments. Based on the genetic variance/covariance structure of this particular population, the linear index which maximized the combined expected gain in both environments was 0.66Y1 + 0.34Y2, in which Y1 and Y2 are yields in the irrigated and drought-stressed environments. This index is not expected to apply across all populations; rather, it further supports the hypothesis that testing in either environment alone (drought stressed or irrigated) may not be most effective for increasing either mean productivity or yield under drought stress.
TL;DR: The metabolism of purine nucleotides and purine alkaloids are reviewed in tea and coffee plants and the activity of the three N -methyltransferases is considered.
TL;DR: Current data suggest that down-regulation of progesterone receptors in the uterine epithelium may initiate events involved in the synthesis and release of prostaglandin F2 alpha (PGF2 alpha) for luteolysis during the bovine oestrous cycle.
Abstract: Regulation and timing of luteolysis during the bovine oestrous cycle is controlled by the initiation and length of progesterone stimulation. Results have demonstrated that early administration of progesterone shortens the interoestrous interval in the ewe and cow, and removal of progesterone stimulation through a progesterone receptor antagonist delays luteolysis in sheep. Current data suggest that down-regulation of progesterone receptors in the uterine epithelium may initiate events involved in the synthesis and release of prostaglandin F2 alpha (PGF2 alpha) for luteolysis. Progesterone is also involved in the stimulation of the uterine secretions that regulate conceptus growth and the release of the bovine trophoblast protein-1 (bTP-1) necessary for inhibiting endometrial PGF2 alpha release. Conceptus secretion of bTP-1, a Type I trophoblast interferon, increases the concentration of the cellular enzyme 2',5'-oligoadenylate synthetase within the endometrium. The biological role of 2',5'-oligoadenylate synthetase in the establishment of pregnancy is discussed.
TL;DR: The electrophoretic mobilities of branched oligosaccharides were indexed with respect to linear homooligosacchcharides, an approach that may prove valuable in correlating and predicting the mobility of complex oligosACcharides.
TL;DR: Data demonstrate that D. andersoni males are efficient vectors of A. marginale and may be potential reservoirs of infection for ruminants for extended periods, and the presence of Anaplasma DNA in midgut and salivary glands throughout the experiment is confirmed.
Abstract: The persistence of Anaplasma marginale Theiler in male Dermacentor andersoni Stiles ticks exposed to the organism as adults was studied as the ticks were successively transferred to five susceptible calves. All calves fed upon by these ticks rapidly developed clinical anaplasmosis; incubation periods of infection ranged from 19 to 26 d and did not change significantly with successive feedings. Development of A. marginale in tick midgut and salivary glands was followed daily during tick feeding (total, 35 d) with light microscopy and DNA hybridization. With microscopy, A. marginale colonies persisted in midgut cells throughout the experiment. Large colonies were observed in gut muscle cells on days 8 through 35 and were the predominant infected cell type during this part of feeding. Colonies were seen in salivary gland acini from day 2 throughout the 35-d experiment. The DNA probe confirmed the presence of Anaplasma DNA in midgut and salivary glands throughout the experiment. Quantitative estimates of infection intensity in tissues of individual ticks approximated 10 initial body equivalents, confirming heavy infections. A. marginale in midgut tissues decreased with feeding time, whereas the estimated number of organisms in salivary glands remained constant. These data demonstrate that D. andersoni males are efficient vectors of A. marginale and may be potential reservoirs of infection for ruminants for extended periods.
TL;DR: Secretagogue-induced saliva of the tick, Amblyomma americanum, was fractionated by reversed-phase-high-performance liquid chromatography (RP-HPLC) and bioassayed in smooth muscle preparations to assist in tick feeding by inducing vasodilation and/or other pharmacological events in their hosts.
TL;DR: In this article, a 10-year-old stand of Pinus taeda L was thinned to three residual basal area levels: 7.8 m 2 ha −1, 12.6 m 2 m −1 and 26.6m 2 m−1 (unthinned).
TL;DR: Fused-silica capillaries having surface-bound octadecyl functions were developed for on-line preconcentration of dilute samples prior to capillary zone electrophoresis as discussed by the authors.
Abstract: Fused-silica capillaries having surface-bound octadecyl functions were developed for on-line preconcentration of dilute samples prior to capillary zone electrophoresis. The performance of tandem octadecyl capillaries-capillary zone electrophoresis was evaluated with solutes of environmental significance, e.g., prorheton and prornetryne. The on-line preconcentration was best achieved when oligomeric octadecyl capillaries having roughened inner walls were employed. The coupled configuration enhanced the detectability in terms of solute concentration by a factor of 10 to 35 as compared to that obtained by capillary zone electrophoresis alone. Large volumes of samples could be introduced without affecting separation efficiency.
TL;DR: In this paper, the octylglucoside-borate micelles with adjustable surface charge density were introduced for micellar electrokinetic capillary chromatography, which allowed the separation of hydrophobic species including herbicides, e.g., prometon, prometryne, propazine and butachlor.
TL;DR: It is indicated that pathogenic strains of M. bovis are not commonly found in the eyes of bulls that do not exhibit clinical signs of IBK, and failure to detect circulating antibody in culture-positive animals in this study demonstrated the difficulty that will be encountered when serologic testing is used for monitoring this disease.
Abstract: (which included the 3 culture-positive bulls) or in sentinel cattle during 120 days of observation. Negative control sera produced a pale green tint after completion of the color reaction. The positive serum had a dark green tint. All test sera were noticeably lighter than the positive control. Results of this study indicate that pathogenic strains of M. bovis are not commonly found in the eyes of bulls that do not exhibit clinical signs of IBK. Isolation of IBK from whiteeye animals of the youngest group examined suggests a genetic or an age-related susceptibility to infection with M. bovis. The relation of eye pigment and propensity for infection has been previously noted. Failure of transmission among the sentinel animals may suggest some level of herd immunity. Because of the small number of positive cultures and the complete lack of ELISA-positive samples, conclusions could not be made regarding correlation of culture results and ELISA or serum antibody titer or regarding the importance of ocular culture-positive asymptomatic bulls serving as carrier animals. Failure to detect circulating antibody in culture-positive animals in this study demonstrated the difficulty that will be encountered when serologic testing is used for monitoring this disease. Acknowledgement. This work was supported by Alabama line item, Food Animal Health and Disease Research Funds and published as Auburn University Publication No. 2207. 3. Blood DC, Radostits OM: 0000, Infectious keratitis of cattle. In: Veterinary medicine, 7th ed., pp. 697-700. Baillier Tindall, Philadelphia, PA. 4. Brown TF, Adkins TR: 1972, Relationship of feeding activity of face fly (Musca autumnalis DeGreer) to production of keratoconjunctivitis in calves. Am J Vet Res 33:2551-2555. 5. Chandler RL, Baptista PJ, Turfrey B: 1979, Studies on the pathogenicity of Moraxella bovis in relation to infectious bovine keratoconjunctivitis. J Comp Pathol 89:441-448. 6. George LW: 1984, Clinical infectious bovine keratoconjunctivitis. Compend Cont Ed 6:S713-S724. 7. Hughes DE, Pugh GW: 1970, A five-year study of bovine infectious keratoconjunctivitis in a beef herd. Am Vet Med Assoc 157:443-451. 8. Hughes DE, Pugh GW, McDonald TJ: 1965, Ultraviolet radiation and Moraxella bovis in the etiology of bovine infectious keratoconjunctivitis. Am J Vet Res 26:1331-1338. 9. Pugh GW, Hughes DE: 1972, Infectious bovine keratoconjunctivitis: Moraxella bovis as the sole etiologic agent in winter epizootic. J Am Vet Med Assoc 161:481-486. 10. Pugh GW, Hughes DE: 1976, Experimental production of infectious bovine keratoconjunctivitis: comparison of serological and immunological response using pili fractions of Moraxella bovis. Can J Comp Med 40:60-66. 11. Pugh GW, Hughes DE, McDonald TJ: 1966, The isolation and characterization of Moraxella bovis. Am Vet Med Assoc 17: 957-962. 12. Pugh GW, McDonald TJ, Kopecky KE: 1980, IBK: effects of vaccination on Moraxella bovis carrier state in cattle. Am J Vet
TL;DR: The capillary enzyme reactors coupled in series with capillary zone electrophoresis served as peak locator on the electropherogram, improved the system selectivity, and facilitated the quantitative determination of the analytes with good accuracy.
TL;DR: In this paper, the pKa values calculated from electrophoretic mobility data obtained by capillary zone electrophoresis were reasonably close to those reported in the literature, and the observed dependence of the electrophoreic mobilities of weak bases and ampholytes on the pH of the electrolyte showed good agreement with predicted behavior.
Abstract: Capillary zone electrophoresis in untreated fused silica capillaries has proved suitable for the determination of the ionization constants of weak electrolytes. Several fundamental equations relating the electrophoretic mobilities of ionized solutes to hydronium ion concentrations in the running electrolyte have been verified experimentally. The observed dependence of the electrophoretic mobilities of weak bases and ampholytes on the pH of the electrolyte showed good agreement with predicted behavior. The pKa values calculated from electrophoretic mobility data obtained by capillary zone electrophoresis were reasonably close to those reported in the literature.
TL;DR: It is concluded that the prophylactic effects on the occurrence of milk fever of feeding a low DCAB during the dry period may be absent when diets contain greater than 1.6% Ca and DCAB is greater than or equal to -3.3%.
Abstract: Our objective was to evaluate the effectiveness of a low dietary cation-anion balance (DCAB) in preventing milk fever and udder edema in dry cows consuming a high-Ca diet and to evaluate the effect of this diet on calves delivered by these cows. Seventy primiparous or multiparous cows and 50 pregnant heifers were offered alfalfa hay-based diets beginning 4 wk before their projected calving date. Diets contained 1.6% Ca and a DCAB of -3 or +9 mEq/100 g of diet DM. Blood and urine samples were collected weekly from 3 wk prepartum until 3 wk postpartum. Blood samples were collected from calves at parturition and weekly thereafter for 3 wk. Feeding a low vs high DCAB in a high-Ca diet for 3 wk prepartum did not reduce the incidence of milk fever; this lack of response may have been attributable to the relatively low DCAB of each diet and the small difference in DCAB between the two diets. Udder edema seemed to regress more rapidly postpartum for cows that had consumed the low DCAB during the dry period. Test diets fed to prepartum cows did not affect systemic acid-base status or plasma mineral content of their calves, although plasma Ca was somewhat lower for calves from cows consuming a low DCAB and was higher for calves from primigravid cows. Correlations of plasma mineral concentration of the cows with those of their calves were highest for plasma Ca (r = .75; P less than .001). We conclude that the prophylactic effects on the occurrence of milk fever of feeding a low DCAB during the dry period may be absent when diets contain greater than 1.6% Ca and DCAB is greater than or equal to -3. The cation-anion balance of the diet consumed by dry cows did not affect the acid-based status or plasma mineral content of their calves.
TL;DR: A similar pattern of inhibition against the different bacteria and fungi was exhibited by both 2,4-diacetylphloroglucinol and strain PFM2 when grown in a medium of the same composition as that in which the antibiotic was produced.
Abstract: Pseudomonas fluorescens strain PFM2, antagonistic to Septoria tritici, also inhibited growth of several other phytopathogenic bacteria and fungi in vitro. Three inhibitory compounds were extracted from liquid glycerol-peptone-phosphate medium in which strain PFM2 was grown for 4 weeks. The compound recovered in greatest quantity (70 mg/1) was identified as 2,4-diacetylphloroglucinol. The other two antibiotics, which were produced in small amounts (< 5 mg/l), were not identified. A similar pattern of inhibition against the different bacteria and fungi was exhibited by both 2,4-diacetylphloroglucinol and strain PFM2 when grown in a medium of the same composition as that in which the antibiotic was produced.
TL;DR: Although evidence of reduced aggression towards neighbours has been reported in a wide variety of species, field studies conducted on naturally established territories are largely restricted to birds, and a field test of the dear enemy phenomenon in male collared lizards is performed.
TL;DR: In this paper, share price reactions of commercial bank common stock issues were examined and negative effects on rival commercial and investment banking firms were found, with no such intra-industry effects for equity issues by industrial firms.
TL;DR: To determine whether systemic and/or intraovarian concentrations of insulin-like growth factor-I (IGF-I) are affected by short-term fasting, 24 heifers were blocked by weight and were assigned to one of three treatments: fasted for 0 h (controls), fasting for 24 h (n = 8), or fastedFor 48 h ( n = 8).
Abstract: To determine whether systemic and/or intraovarian concentrations of insulin-like growth factor-I (IGF-I) are affected by short-term fasting, 24 heifers were blocked by weight and, within block, were assigned to one of three treatments: fasted for 0 h (controls; n = 8), fasted for 24 h (n = 8), or fasted for 48 h (n = 8). Blood plasma was collected every 8 h from -64 h to 0 h before ovariectomy (OVEX). OVEX was performed per vagina under local anesthesia during the follicular phase of an estrous cycle (36-42 h after synchronization with prostaglandin-F2 alpha). Follicular fluid (FFL) and granulosa cells were collected individually from follicles greater than or equal to 6 mm (large), and FFL was pooled from follicles 1.0-5.9 mm (small) in diameter. Fasting did not affect (p greater than 0.20) the number (mean +/- SE) of small (52 +/- 7) or large (1.5 +/- 0.4) follicles per heifer, specific binding of 125I-hCG to granulosa cells of follicles greater than or equal to 8 mm in diameter, or concentrations of progesterone in FFL of small follicles. At OVEX, body weight was less (p less than 0.01) for 24 h- and 48 h-fasted heifers (412 +/- 7 kg and 399 +/- 7 kg, respectively) than for 0 h-fasted heifers (442 +/- 7 kg). At OVEX, plasma concentrations of IGF-I were lower (p less than 0.05) in the 48 h-fasted group (105 +/- 8 ng/ml) than in the 0 h-fasted group (140 +/- 8 ng/ml).(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: The effect of a decision aid is found to be contingent on familiarity with the decision aid, task familiarity, and the interaction of these two factors, indicating that decision aids influence the problem-solving processes of decision makers.
Abstract: Despite the growing number of investigations examining decision support systems (DSS), relatively few empirical studies have evaluated the effects of DSS on problem-solving processes. This study uses protocol analysis to investigate the impact of a specific decision aid on problem-solving processes in a semi-structured problem. Results indicate that decision aids influence the problem-solving processes of decision makers. The effect of a decision aid is found to be contingent on familiarity with the decision aid, task familiarity, and the interaction of these two factors. Suggestions for incorporating interaction effects and problem-solving processes into future examinations are proposed.