Showing papers by "University of Vermont published in 1986"
Book•
01 Jan 1986TL;DR: Kernell as mentioned in this paper examines the increasingly frequent presidential practice of "going public" - appealing for support directly to the American public, often bypassing Congress - and argues that the presidential practice has fundamentally altered the relationship between the executive and legislative branches.
Abstract: In this new edition of his authoritative work, Samuel Kernell examines the increasingly frequent presidential practice of "going public" - appealing for support directly to the American public, often bypassing Congress. Updated to include timely analyses of the public strategies of President Clinton, who by most measurements has engaged in more public activities than any other president, the third edition carefully traces the history of this practice and explores the key political role played by the news media. Trends in presidential speeches, public appearances, and travel receive special attention as does the influence of public opinion. Kernell contends that the presidential practice of going public has fundamentally altered the relationship between the executive and legislative branches. He supports his argument with many examples of going public from recent presidencies.
771 citations
TL;DR: Strain in the ACL during simultaneous hamstring and quadriceps activity was significantly higher than that during passive normal motion from full extension to 30° of flexion, indicating hamstring exercises are not detrimental to ACL repairs or reconstruction and can be included early in the rehabilitation program after ACL surgery.
Abstract: The objectives of this study were to measure strain in the ACL during simulated: hamstring activity alone, quadriceps activity alone, and simultaneous quadriceps and hamstring activity. Seven knee specimens removed from cadavers were studied. Heavy sutures applied to load cells were attached to the hamstring and quadriceps tendons. Loads were then applied manually (hamstrings) and/or with an Instron testing machine (quadriceps) to simulate isometric contractions of the various muscle groups. Strain was measured using a Hall effect transducer. Acting alone, the isometric hamstring activity decreased ACL strain relative to the passive normal strain at all positions tested. Thus, hamstring exercises are not detrimental to ACL repairs or reconstruction and can be included early in the rehabilitation program after ACL surgery. Acting alone, at flexion angles of 0 degree to 45 degrees, the quadriceps significantly increased the strain within the ACL relative to the passive normal strain. Strain in the ACL during simultaneous hamstring and quadriceps activity was significantly higher than that during passive normal motion from full extension to 30 degrees of flexion. The hamstrings are not capable of masking the potentially harmful effects of simultaneous quadriceps contraction on freshly repaired or reconstructed ACLs unless the knee flexion angle exceeds 30 degrees.
572 citations
TL;DR: Two noncomplementing mutants are selected that are nearly 100 times more resistant than wild-type to either methoprene or juvenile hormone III topically applied or incorporated into the diet of Drosophila melanogaster larvae and adults.
231 citations
TL;DR: In this article, a comparison of the relative vulnerability of xylem conduits to cavitation and embolism in three species was made, and the authors found that the vessel bearing wood retained water better than tracheid bearing wood.
Abstract: A comparison was made of the relative vulnerability of xylem conduits to cavitation and embolism in three species [Thuja occidentalis L., Tsuga canadensis (L.) Carr. and Acer saccharum Marsh.]. Waterlogged samples of wood were air dehydrated while measuring relative water loss, loss of hydraulic conductance, cumulative acoustic emissions (= cavitations) and xylem water potential. Most cavitation events and loss of hydraulic conductance occurred while water potential declined from – 1 to –6 MPa. There were differences in vulnerability between species. Other people have hypothesized that large xylem conduits (e.g. vessels) should be more vulnerable to cavitations than small conduits (e.g. tracheids). Our findings are contrary to this hypothesis. Under water stress, the vessel bearing wood retained water better than tracheid bearing wood. However, within a species large conduits were more prone to cavitation than small conduits.
228 citations
TL;DR: In this paper, the relationship between negative events and disorder was moderated by gender, the types of events experienced, and anticipated change in the psychosocial environment, highlighting the importance of the use of standardized and psychometrically sound measures of life events, social support, and psychological disorder.
Abstract: Relationships among major life events, perceived social support, and psychological disorder were assessed in a sample of older adolescents. Negative life events and satisfaction with social support were significantly and independently related to a range of psychological symptoms. Further, the relationship between negative events and disorder was moderated by gender, the types of events experienced, and anticipated change in the psychosocial environment. The importance of the use of standardized and psychometrically sound measures of life events, social support, and psychological disorder is highlighted.
205 citations
TL;DR: Although numbers of adult ants changed with addition of nest sites, the numbers of immatures were no different after 2 years, suggesting that the population was undergoing growth to expand into the additional sites.
Abstract: The ant L. longispinosus displays geographic variation in its pattern of facultative polygyny (Fig. 2). In nature, nest density and frequency of multiple queening are positively associated over three sites. A putative causal relation between availability of vacant nest sites and polygyny was examined in New York, where a plot was seeded with additional nest sites and monitored for 24 months. Both queen number and worker number per nest on the experimental plot were reduced relative to controls (Fig. 4, Fig. 5), indicating that scarcity of available nest sites influences the pattern of polygyny in this species. The observed demographic changes resulted from fractionation of existing colonies; adding nest sites induced polydomy. Although numbers of adult ants changed with addition of nest sites, the numbers of immatures were no different after 2 years (Table 1), suggesting that the population was undergoing growth to expand into the additional sites. These results are the first direct experimental evidence linking polygyny to an ecological parameter for any ant species.
195 citations
185 citations
TL;DR: Direct evidence for the existence of an ecto-protein kinase is presented and endogenous substrates for its activity at the surface of intact neural cells are demonstrated, suggesting a role for surface protein phosphorylation in regulating specific functions of developing and mature neurones.
Abstract: ATP is secreted in association with neurotransmitters at certain synapses and neuromuscular junctions1,2. Extracellular ATP is known to exert potent effects on the activity of cells in the nervous system, where it can act as a neurotransmitter or as a modulator regulating the activity of other neurohormones3–5. We have suggested that such modulation may involve the activity of extracellular protein phosphorylation systems6. It is well known that intracellular protein kinases are important in the regulation of various neuronal functions6–8, but protein kinases which use extracellular ATP to phosphorylate proteins localized at the external surface of the plasma membrane (ecto-protein kinases) have not been demonstrated in neuronal cells. Here we present direct evidence for the existence of an ecto-protein kinase and demonstrate endogenous substrates for its activity at the surface of intact neural cells. The phosphorylation of one of these surface proteins is selectively stimulated during cell depolarization. In addition, neuronal cell adhesion molecules (N-CAMs) appear to be among the substrates of ecto-protein kinase activity. These results suggest a role for surface protein phosphorylation in regulating specific functions of developing and mature neurones.
180 citations
TL;DR: The dependence of the amplitude and timing of the pre-stimulus negativity on the temporal location of information, in conjunction with its independence of motor response requirement, suggests that thePre- Stimulus negativity reflects some operation in the domain of expectancy, anticipation or 'mental preparation' for the informational stimulus.
163 citations
TL;DR: It is proposed that the cascade of inflammatory and fibrotic events involved in cell-mediated, and possibly humoral, immune responses also produces silicosis, and provides a model of chronic diffuse interstitial immunologic and Fibrotic lung disease in which the cause is known, can be applied in defined doses, and tracked in the lung throughout the course of the disease.
Abstract: Silicosis is caused by the inhalation of crystalline silica (silicon dioxide, SiO2) in various forms. This review proposes that the cascade of inflammatory and fibrotic events involved in cell-mediated, and possibly humoral, immune responses also produces silicosis. The hypothesis rests on the central concept that interactions between silica and pulmonary macrophages are the pivotal events in the pathogenesis of silicosis. Resident and recruited pulmonary macrophages demonstrate intimate contact with silica from the moment of deposition, and throughout the time the particles remain in the lung. The silica probably exerts its effects on the macrophages that ingest it by altering their function while they are alive, rather than merely by disrupting them. The macrophage appears to be stimulated to secrete mediator substances, such as interleukin-1 (IL-1), which alter the function and behavior of other cells. Lymphocytes and macrophages appear in close proximity to one another in developing silicotic nodules, and increased proportions of lymphocytes are found in bronchoalveolar lavage specimens from animals and humans with silica dust exposure. Hypothetically, macrophages influence and activate lymphocytes, which then feed back to amplify the response by stimulating the same or other recruited macrophages. An expanded and activated population of lymphocytes under the influence of IL-1 in turn can secrete a variety of lymphokines which profoundly alter monocyte/macrophage function. The macrophage has been implicated as a major cause for the fibrosis that accompanies silicosis. The products of activated T-lymphocytes, particularly interferon-gamma (IF-g), are potent stimulators of secretion from macrophages of a fibroblast growth competence factor, macrophage-derived growth factor (MDGF). IL-1 may have an additional stimulatory effect on fibroblasts. Neutrophils and macrophages also may be important in silicosis because of their potent ability to cause lung tissue injury. Silicosis provides a model of chronic diffuse interstitial immunologic and fibrotic lung disease in which the cause is known, can be applied in defined doses, and tracked in the lung throughout the course of the disease. Further studies should provide better understanding of the mechanisms that goven pulmonary injury, inflammation, repair, and fibrosis.
144 citations
Journal Article•
TL;DR: In vivo therapy with monoclonal antibody GK1.5, which recognizes a glycoprotein antigen designated L3T4 on murine helper T lymphocytes, either prevented or suppressed the development of murine lupus, autoimmune encephalomyelitis, and collagen arthritis.
Abstract: In vivo therapy with monoclonal antibody (mAb) GK1.5, which recognizes a glycoprotein antigen designated L3T4 on murine helper T lymphocytes, either prevented or suppressed the development of murine lupus, autoimmune encephalomyelitis, and collagen arthritis. The L3T4 antigen in the mouse is analogous to the human Leu-3/T4 antigen expressed on helper T lymphocytes, because they both participate in the T cell response to class II major histocompatibility complex (MHC) antigens. Class II MHC genes and I-A antigens mediate murine experimental autoimmune myasthenia gravis (EAMG) induced by acetylcholine receptor (AChR) autoimmunity. We studied the efficacy of mAb GK1.5 as an immunotherapeutic agent for murine EAMG. Therapy with mAb GK1.5 not only suppressed established autoimmunity to AChR but also prevented loss of muscle AChR in mice with EAMG. Moreover, permanent remission of clinical muscle weakness was induced if mAb GK1.5 therapy was initiated after the onset of clinical disease. Because the function of the Leu-3/T4 determinant on human helper T lymphocytes is analogous to the murine L3T4 determinant, use of antibody to the Leu-3/T4 determinant as an immunotherapeutic agent may provide a way to control the progression of human MG.
TL;DR: The psychrotrophic growth of L. monocytogenes serotype 4b strains was enhanced in whole milk when compared to skim milk or 11% NFMS, and pasteurization as defined by current FDA guidelines should eliminate this organism from raw milk with a large margin of safety.
TL;DR: The myoelectric activity of selected trunk muscles at the L3 level was studied during the development of a controlled isometric axial torque, suggesting that a considerable amount of the muscle contraction was used to control the posture.
TL;DR: The present findings are consistent with the view that CS processing may decline either as a function of stimulus exposure or as the CS becomes a good predictor of nonreinforcement and compared to other findings suggesting that CSs retain some of their excitatory power even after prolonged extinction training.
TL;DR: For example, this article found that both the acquisition and maintenance of smoking are influenced by heredity, and that the magnitude of the effect of heredities on smoking is small but similar to that for alcohol use.
TL;DR: Protoplasts of aSchizophyllum commune tryptophan auxotroph (trp1), deficient in indole-3-glycerol phosphate synthetase (IGPS), were transformed to trp+ with plasmid DNA containing the SchizophyLLumTRP1 sequence, revealing that the transforming DNA is integrated in chromosomal DNA.
Abstract: Protoplasts of aSchizophyllum commune tryptophan auxotroph (trp1), deficient in indole-3-glycerol phosphate synthetase (IGPS), were transformed to trp+ with plasmid DNA containing the SchizophyllumTRP1 sequence. Efficiencies up to 30 transformants per microgram of plasmid DNA were obtained. Southern blots reveal that the transforming DNA is integrated in chromosomal DNA. The trp+ phenotype of transformants is stable in meiosis and mitosis. Transformants possess IGPS activity comparable to wild-type cells.
TL;DR: Small particle size, autoclaved rumen fluid, buffer solutions, and specific salts increased the rate of change of functional specific gravity of particles in the rumen.
TL;DR: There are no differences in thermogenic responses to NE in human obesity to account for excessive fat deposition and overfeeding does not increase the thermogenetic responses toNE in humans as has been reported in small mammals.
Abstract: Overfeeding increases the thermogenic response of norepinephrine (NE) in normal but not in certain genetically obese rodents. It has been suggested that human obesity may be associated with a similar thermogenic defect. To determine whether there are differences in the thermogenic sensitivity to NE in human obesity, energy expenditure in response to graded infusions of NE (0.05, 0.10, 0.15, 0.20 micrograms/min/kg fat-free mass) was measured in six lean and six obese subjects (9.5 +/- 1.8 v 36.3 +/- 3.8% body fat P less than 0.005). Resting metabolic rate (RMR), thermogenic response to NE, and thermogenic response to exercise were measured during weight maintenance and during the third week of feeding 1000 extra Kcal/d in the lean and obese subjects. These components of energy expenditure were also measured in the obese subjects during the third week of a 589 Kcal/d diet. Resting metabolic rate increased during overfeeding in lean (6.6%, P less than 0.05) but not in the obese subjects (2.7%, P = NS) and fell during underfeeding in the obese (-9.1%, P less than 0.02). There was a logarithmic increment above baseline in VO2 v plasma NE concentration during the NE infusions (r = 0.75, P less than 0.005) in lean subjects which was unaltered by overfeeding. The obese exhibited equivalent VO2 responses to NE to that measured in the lean. Supine plasma NE concentrations were lower but metabolic clearance rates (MCR) of NE were similar in the obese compared to lean subjects during both weight maintenance and overfeeding. Overfeeding minimally increased plasma concentration but not MCR of NE in both groups. The thermogenic response to exercise was similar in the lean and obese subjects and was unaltered by overfeeding or underfeeding. The increments in plasma glycerol and free fatty acid in response to the NE infusions were proportional to the total fat mass of each individual and were greater in the obese subjects. Overfeeding partially suppressed the lipolytic response to NE in both groups and underfeeding increased the lipolytic response in the obese. There are no differences in thermogenic responses to NE in human obesity to account for excessive fat deposition. Overfeeding does not increase the thermogenetic responses to NE in humans as has been reported in small mammals.
TL;DR: Clinicians must remember the importance of making the gravity correction in patients with reduced torque output where the gravitational torque is a greater percentage of the measured torque to ascertain correctly the relative strength of antagonists inversely affected by gravity.
Abstract: The purpose of our investigation was to compare, for the hamstring and quadriceps femoris muscles, peak torque values uncorrected for gravity with the peak torque values corrected for gravity and to determine the effect of making this correction on the hamstring to quadriceps femoris muscle peak torque ratio at slow and fast isokinetic speeds. We measured peak torques isokinetically at 60 degrees/sec (slow) and 240 degrees/sec (fast) in 25 female university soccer players. The gravity effect torque (GET) is the torque resulting from the effect of gravity on the combined weight of the leg and dynamometer arm at the precise angle of extension and flexion peak torque. The GET was added to the measured quadriceps femoris muscle peak torque and subtracted from the hamstring muscle peak torque to yield gravity corrected values. Failure to consider GET greatly underestimated quadriceps femoris muscle torque and overestimated hamstring muscle torque and the ratio between these torques at both speeds. Whereas the uncorrected hamstring to quadriceps femoris muscle peak torque ratio increased as speeds went from 60 degrees/sec to 240 degrees/sec, the gravity corrected ratio significantly decreased. Clinicians must remember the importance of making the gravity correction in patients with reduced torque output where the gravitational torque is a greater percentage of the measured torque to ascertain correctly the relative strength of antagonists inversely affected by gravity.
TL;DR: Extemporaneously prepared beads of bone cement are effective for delivering high concentrations of tobramycin to an infection site and release of tobramsycin from the beads in vitro and after implantation in a patient are described.
Abstract: Preparation of tobramycin-impregnated polymethylmethacrylate (PMMA) bone cement beads and release of tobramycin from the beads in vitro and after implantation in a patient are described. Tobramycin sulfate powder 1.2 g was mixed with Palacos PMMA bone cement 40 g in a custom-made mold to produce 25 beads containing 3.26 mg tobramycin (as the sulfate salt) per bead. Chains of the beads, strung on stainless-steel suture, were sterilized with ethylene oxide. Three single beads were each placed in multiple-electrolyte solution (pH 7.4); the solution was removed and replaced with fresh solution every 24 hours for 28 days. The tobramycin content of each day's solution was determined by fluorescence polarization immunoassay. After day 28, solution was removed weekly for assay until day 84. Tobramycin concentrations were measured in drainage from the surgical wound after six chains of tobramycin-PMMA bone cement beads were implanted in the right acetabulum and femur of a patient whose hip prosthesis had been removed because of infection. Tobramycin concentrations in the dissolution medium averaged 34.3 micrograms/mL initially, and 7.5 micrograms/mL on day 2, gradually decreasing to 0.6 microgram/mL on day 28. Release of tobramycin followed a predictable pattern, and variation among samples was small. Over 12 weeks, less than 20% of the theoretically available tobramycin from a single bead was released. Tobramycin concentration in wound drainage was 90.0 micrograms/mL during the first 24 hours after surgery, while serum tobramycin concentrations were less than 0.5 microgram/mL. Extemporaneously prepared beads of bone cement are effective for delivering high concentrations of tobramycin to an infection site.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: Results of this study of 12--16 year-old boys are compared to previously published findings for younger LD boys and no relationship was found between IQ scores on the Wechsler Intelligence Test for Children-Revised and social competence and behavior problem scores.
Abstract: Parents' reports on social competence and behavioral problems were obtained for 53 learning disabled boys 12--16 who were referred for a psychoeducational assessment at the Center for Disorders of Communication at the University of Vermont. One parent of each boy completed the Child Behavior Checklist developed by Achenbach and Edelbrock (1983). On average, the LD boys showed significantly lower levels of social competence and more behavior problems compared to normative samples of boys in the same age range. On the social competence scales, the LD boys were significantly lower than the normative samples in their participation in activities, their social involvement and school performance. On the behavior problem scales, the LD boys had significantly higher scores for total problems and “externalizing” and “internalizing” types of problems. The LD boys had high scores compared to normal boys on several CBCL scales reflecting immaturity, hostile-withdrawal, aggressiveness and hyperactivity. Compared to a s...
TL;DR: The results suggest that mutation in vivo of the hprt gene in human T-lymphocytes occurred after thymic maturation and that the 11 recovered hPRt mutants probably resulted from 11 independent mutational events.
TL;DR: The pharmacokinetics, thrombolytic profile and effects on hemostasis of graded intravenous doses of recombinant human tissue-type plasminogen activator (rt-PA) were studied in 45 patients with acute myocardial infarction and the efficacy of rt-PA for coronary thrombalysis was dose-dependent.
Abstract: The pharmacokinetics, thrombolytic profile and effects on hemostasis of graded intravenous doses of recombinant human tissue-type plasminogen activator (rt-PA) were studied in 45 patients with acute myocardial infarction. Infusion of rt-PA at a rate of 4 to 8.3 micrograms/kg/min resulted in plateau levels of the drug in plasma of 0.52 to 1.4 micrograms/ml. A linear relation between infusion rate and plasma rt-PA concentration was observed, although plasma drug levels varied substantially among subjects who received infusions at the same rate. The ratio between plateau levels of rt-PA in plasma and infusion rate was inversely related to initial distribution volume (7.3 +/- 2.9 liters, n = 21). The decline in plasma concentration of rt-PA, x(t), as a function of time after cessation of the infusion, was described adequately by the biexponential equation: x(t) = 0.71exp(-0.13t) + 0.29exp(-0.015t). The initial and terminal half-lives of rt-PA in the blood were 5.3 +/- 1.7 and 46.2 +/- 14 minutes, respectively. The efficacy of rt-PA for coronary thrombolysis was dose-dependent. With 4 micrograms/kg/min of rt-PA for 90 minutes, no reperfusion was achieved, whereas infusion rates of 5 micrograms/kg/min or more for 90 minutes accomplished reperfusion in more than 80% of the patients. However, the frequency of occurrence of residual intraluminal thrombus was significantly lower with an infusion rate of 7 micrograms/kg/min for 90 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: The results suggest that the difference in the conditionability of the cup and drink odors, and not their status as distal and proximal cues, may be critical in the production of potentiation of weakly conditionable target stimuli.
TL;DR: The new WK/HA strain, together with the WKY control strain, is considered as more suitable for subjects in studying hyperactivity in rats than the original SHR strain with its concomitant hypertension and poor habituation traits.
TL;DR: The result suggests that physical dependence may be a cause of behavioral dependence on nicotine gum (ie, use of gum beyond the recommended period) and physicians should emphasize the need for gradual reduction of nicotine gum.
Abstract: To test whether ex-smokers become physically dependent on nicotine in gum, we entered eight ex-smokers who were using nicotine gum into a randomized, double-blind, placebo-substitution trial. When placebo was substituted, seven of the eight subjects were observed to have withdrawal symptoms and two relapsed to smoking or nicotine gum. This result suggests that physical dependence (ie, withdrawal) may be a cause of behavioral dependence on nicotine gum (ie, use of gum beyond the recommended period) and physicians should emphasize the need for gradual reduction of nicotine gum. ( JAMA 1986;255:3277-3279)
TL;DR: The ability of filarial glutathione S-transferases to detoxify electrophilic xenobiotics, at least those from D. immitis, suggests a potential role for these enzymes in the leukotriene synthetic pathway, if filariae can form such eicosanoids from arachidonate.
TL;DR: It is shown that phosphorylated and non-phosphorylated neurofilament accumulate in aluminum-induced NFTs, thus complementing the previously demonstrated specific slowing of the axonal transport of neurofilaments in aluminum intoxication and suggesting that the presence of microtubular proteins may be necessary for altered neuro Filaments to take on a paired helical configuration.
Abstract: Exposure of the central nervous system (CNS) of rabbits to aluminum salts produces a progressive encephalopathy Examination of CNS structures discloses widespread perikaryal neurofibrillary tangle (NFTs) formation The aluminum-induced NFTs consist of collections of normal neurofilaments, and differ ultrastructurally and in their solubility characteristics from Alzheimer-type NFTs, the latter being composed of largely insoluble paired helical filaments The present study compares NFTs found in the rabbit to those of Alzheimer's disease, using monoclonal antibodies (SMI 31, SMI 32) that recognize phosphorylated and non-phosphorylated determinants respectively in normal neurofilaments, and an antiserum raised against purified microtubules Paraffin-embedded sections were stained by the avidin-biotin immunocytochemical method Intense staining of aluminum-induced NFTs was found after processing with SMI 31 and SMI 32, while no staining of non-tangled perikarya of control rabbits or of Alzheimer-type NFTs was seen Antimicrotubule anti-serum gave weak, nonfocal staining in the aluminum-treated and control rabbits, while Alzheimer-type NFTs were stained intensely These results show that phosphorylated and non-phosphorylated neurofilaments accumulate in aluminum-induced NFTs, thus complementing the previously demonstrated specific slowing of the axonal transport of neurofilaments in aluminum intoxication Further, they suggest that the presence of microtubular proteins may be necessary for altered neurofilaments to take on a paired helical configuration