Showing papers by "University of Vermont published in 1987"
TL;DR: A lack of significant r's with the Minnesota Child Development Inventory, Bayley, and McCarthy indicate that the CBCL/2–3 taps behavioral/emotional problems independently of the developmental variance tapped by these measures.
Abstract: The aim was to determine whether ratings of 2- and 3-year-olds could yield more differentiation among their behavioral/emotional problems than the internalizing-externalizing dichotomy found in previous studies. The 99-item Child Behavior Checklist for Ages 2-3 (CBCL/2-3) was designed to extend previously developed empirically based assessment procedures to 2-and 3-year-olds. Factor analyses of the CBCL/2-3 completed by parents of 398 2- and 3-year-olds yielded six syndromes having at least eight items loading greater than or equal to .30 and designated as Social Withdrawal, Depressed, Sleep Problems, Somatic Problems, Aggressive, and Destructive. Second-order analyses showed that the first two were related to a broad-band internalizing grouping, whereas the last two were related to a broad-band externalizing grouping. Scales for the six syndromes, two broad-band groupings, and total problem score were constructed from scores obtained by 273 children in a general population sample. Mean test-retest reliability r was .87, 1-year stability r was .69, 1-year predictive r with CBCL/4-16 scales at age 4 was .63, 2-year predictive r was .55, and 3-year predictive r was .49. Children referred for mental health services scored significantly higher than nonreferred children on all scales. A lack of significant r's with the Minnesota Child Development Inventory, Bayley, and McCarthy indicate that the CBCL/2-3 taps behavioral/emotional problems independently of the developmental variance tapped by these measures.
803 citations
TL;DR: In this paper, a review of the literature concerned with life events and stress during childhood and adolescence is presented, with a focus on the role of chronic strains and daily stressors than major life events in the development of psychological and behavioral difficulties.
495 citations
TL;DR: In this article, the authors investigated interactions between cognitive appraisals of, and coping with, stressful life events and their relationship with psychological symptomatology, and found that the "goodness of fit" between appraisal of the controllability of events and the use of problem-and emotion-focused coping was assessed for major life events.
Abstract: The present study investigated interactions between cognitive appraisals of, and coping with, stressful life events and their relationship with psychological symptomatology. Specifically, the “goodness of fit” between appraisals of the controllability of events and the use of problem- and emotion-focused coping was assessed for major life events and daily hassles. In relation to major life events, symptomatology was high when there was a poor fit between appraisals and coping (e.g., trying to change a stressor that was appraised as uncontrollable) and low when there was a good fit between appraisals and coping (e.g., palliating one's emotions when a stressor was perceived as uncontrollable). No effects were found in relation to daily hassles. Results were generally consistent with cognitive-transactional models of stress and coping.
427 citations
TL;DR: Interspecific differences in short-duration powered flight and takeoff ability are shown to be caused primarily by differences in flight muscle ratio, which ranges from 0.115 to 0.560 among species studied to date.
Abstract: Maximum lift production during takeoff in still air was determined for a wide variety of insects and a small sample of birds and bats, and was compared with variation in morphology, taxonomy and wingbeat type. Maximum lift per unit flight muscle mass was remarkably similar between taxonomic groups (54–63 N kg−1), except for animals using clap-and-fling wingbeats, where muscle mass-specific lift increased by about 25 % (72–86 N kg−1). Muscle mass-specific lift was independent of body mass, wing loading, disk loading and aspect ratio. Birds and bats yielded results indistinguishable from insects using conventional wingbeats. Interspecific differences in short-duration powered flight and takeoff ability are shown to be caused primarily by differences in flight muscle ratio, which ranges from 0.115 to 0.560 among species studied to date. These results contradict theoretical predictions that maximum mass-specific power output and lift production should decrease with increasing body mass and wing disk loading.
411 citations
TL;DR: Xylem vessels in grapevines growing in New England contained air over winter and yet filled with xylem sap and recovered their maximum hydraulic conductance during the month before leaf expansion in late May, suggesting that the decrease in permeability with hydration is due to formation of water films across pores in intervascular pit membranes.
Abstract: Xylem vessels in grapevines Vitis labrusca L. and Vitis riparia Michx. growing in New England contained air over winter and yet filled with xylem sap and recovered their maximum hydraulic conductance during the month before leaf expansion in late May. During this period root pressures between 10 and 100 kilopascals were measured. Although some air in vessels apparently dissolved in ascending xylem sap, results indicated that some is pushed out of vessels and then out of the vine. Air in the vessel network distal to advancing xylem sap was compressed at about 3 kilopascals; independent measurements indicated this was sufficient to push air across vessel ends, and from vessels to the exterior through dead vine tips, inflorescence scars, and points on the bark. Once wetted, vessel ends previously air-permeable at 3 kilopascals remained sealed against air at pressures up to 2 and 3 megapascals. Permeability at 3 kilopascals was restored by dehydrating vines below −2.4 megapascals. We suggest that the decrease in permeability with hydration is due to formation of water films across pores in intervascular pit membranes; this water seal can maintain a pressure difference of roughly 2 megapascals, and prevents cavitation by aspirated air at xylem pressures less negative than −2.4 megapascals.
292 citations
TL;DR: The conditions defined in this study appear to provide a quantitative measurement of the in vivo TGr mutant frequency in human T-lymphocytes, and are independent of inoculum size.
Abstract: Cell cloning by limiting dilution in 96-well microtiter plates has been employed to isolate colonies of human T-lymphocytes resistant to the purine analogue, 6-thioguanine (TG). These colonies show stability of the TG-resistant (TG1) phenotype, lack hypoxanthine guanine phosphoribosyl transferase (HPRT) activity and thus appear to be the result of in vivo somatic cell mutation events. In order to employ this T-lymphocyte cloning assay for quantitative determination of the in vivo TGr mutant frequency in humans, we have defined the optimal conditions for T-cell colony formation with both nonselected and TG-selected cells. The parameters investigated include medium, serum, amount of the mitogen phytohaemagglutinin, amount of T-cell growth factor (TCGF) and the number of irradiated feeder or accessory cells. Under the optimal conditions, the fraction of positive wells is proportional to the number of cells plated per well with both nonselection and TG selection conditions. T-cell cloning efficiencies therefore are independent of inoculum size. There was some evidence for a decline in TGr mutant cell cloning at densities greater than 2 x 10(4) cells per round-bottom well, possibly due to metabolic cooperation between wild-type and mutant cells. The conditions defined in this study appear to provide a quantitative measurement of the in vivo TGr mutant frequency in human T-lymphocytes.
179 citations
Abstract: Decision support systems (DSSs) are more complex than most other traditional decision-aid systems. For what types of problems are they more effective, and what design characteristics make them more effective? The laboratory experiment reported here examined the effect of three design characteristics of these systems in the context of decision makers faced with ill-structured problems. The characteristics were presence or absence of decision-aid heuristics, degree of interaction between the user and the system, and whether or not the system was computerized. The dependent variables were (1) quality of user performance, (2) user productivity of ideas, (3) user confidence in the quality of his/her performance, (4) user satisfaction with the decision aid or support system, (5) changes in user attitude toward the problem addressed, and (6) changes in user attitude toward computers.
Use of heuristics and increased interaction had positive effects on decision quality, user productivity, and attitude toward computers; they had negative effects on user confidence, satisfaction, and attitude toward the problem addressed. Whether or not the system was computerized did not have a significant effect on any dependent variable. The findings concerning negative effects, in particular, suggest the need for research on the design of heuristics for addressing ill-structured problems—heuristics that will deliver the positive but not the negative effects observed in this study. The findings also suggest the need for research on how to benefit from computers in the context of solving ill-structured problems.
173 citations
TL;DR: Surprisingly, it is found that glucose-induced thermogenesis was reduced in association with loss of the early phase of insulin release and this could provide a possible mechanism that could lead eventually to obesity and diabetes.
Abstract: Loss of the early phase of insulin release has been documented in both type I (insulin-dependent) and type II (non-insulin-dependent) diabetes; however, the physiological importance of this loss is unsettled. We created a model of loss of the early phase of insulin release in normal volunteers. Somatostatin (SRIF) was briefly infused (from -5 to 15 min) during intravenous (IVGTT) and oral (OGTT) glucose tolerance tests. The thermic response to oral glucose was determined under these conditions by indirect calorimetry. Early insulin release was totally blocked during IVGTT and OGTT by SRIF infusion. During the IVGTT, glucose tolerance was deteriorated in association with loss of the early phase of insulin release as indicated by a decrease in the K value (control 1.9 +/- 0.36 vs. SRIF 1.1 +/- 0.27, P less than .001). Higher plasma glucose concentrations were observed during SRIF tests in the OGTT at 60, 90, 120, 150, and 180 min; total glycemic excursion was larger during the SRIF test (9473 +/- 3089 mg X dl-1 X 5 h-1) when compared with the control condition (6583 +/- 2329 mg X dl-1 X 5 h-1). During the OGTT the total amount of glucose oxidized (control 56 +/- 4.2 vs. SRIF 55 +/- 3.4 g/5 h) was similar in both conditions, suggesting that nonoxidative pathways of glucose disposal were responsible for the deterioration in glucose tolerance. Surprisingly, we found that glucose-induced thermogenesis was reduced in association with loss of the early phase of insulin release (control 102 +/- 21.3 vs. SRIF 72 +/- 27.8 J/5 h, P less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)
173 citations
TL;DR: Although this group of patients, taken as a whole, showed a tendency toward abnormal intersegmental motion of the lumbar spine, it was found that flexion-extension biplanar radiography was not useful in the diagnosis of lumbr instability.
Abstract: Seventy-eight patients were categorized as having degenerative instability in the lumbar spine, based on clinical symptoms and radiologic signs. Biplanar radiography was used to measure the angular and translational intersegmental motion components of flexion and extension of the lumbar spine. A comparison was made between this measured motion, the clinical symptoms, response to facet joint injection of anesthetic, and radiologic appearance of disc space and facets. The magnitude of the flexion motion and the magnitude of the anteroposterior (AP) shear motion accompanying the flexion was slightly less at symptomatic compared with nonsymptomatic levels. In most patients the AP shear motion at all levels was less than 3 mm (maximum 7 mm). The amount of forward shear motion correlated positively with the amount of flexion motion (r = 0.3). The shear-flexion ratio was significantly reduced at symptomatic levels of patients. Although this group of patients, taken as a whole, showed a tendency toward abnormal intersegmental motion of the lumbar spine, it was found that flexion-extension biplanar radiography was not useful in the diagnosis of lumbar instability.
161 citations
TL;DR: There was no evidence of an abnormality of sagittal curvature of a magnitude to implicate it in the etiology or in the treatment, and mechanical measures to correct this spinal deformity or to prevent progression should apply different rotations to the apex.
142 citations
TL;DR: It is postulated that the functional dependence between erector spinae muscle activity and the applied lifting moments about the spine is as follows: the sum of left and right erectorSpinae processed EMG depends on the sagittal plane moment, and the difference ofleft and right erection spinaE processing EMG depend on the frontal plane moment.
TL;DR: Serial rest and upright cycle exercise 2-dimensional echocardiographic studies were performed in 7 healthy young men during acclimatization to a simulated altitude of 29,000 feet, finding LV systolic function is not a limiting factor in compromising the exercise capacity of normal humans on ascent to high altitude, even to the peak of Mt. Everest.
Abstract: Serial rest and upright cycle exercise 2-dimensional echocardiographic studies were performed in 7 healthy young men during acclimatization to a simulated altitude of 29,000 feet (barometric pressure [PB] 240 torr) in a chamber for 40 days In all subjects left ventricular (LV) end-diastolic, end-systolic and stroke volumes progressively decreased, with mean reductions of 21%, 40% and 14%, respectively, on ascent to 25,000 feet (PB 282 torr) at rest, and reductions of 23%, 43% and 14% during 60-W exercise At PB 282 torr, mean arterial blood O2 partial pressures were 37 torr (rest) and 32 torr (exercise), with corresponding O2 saturations of 68% and 59% All 3 indexes of LV systolic function examined--ejection fraction, ratio of peak systolic pressure to end-systolic volume and mean normalized systolic ejection rate at rest--were sustained in all subjects at high altitude despite reduced preload, pulmonary hypertension and severe hypoxemia Increases in ejection fraction of 6% at rest and 10% during exercise developed at PB 282 torr and a higher mean normalized systolic ejection rate in association with elevated circulating catecholamines reflecting enhanced sympathetic activity LV systolic function is not a limiting factor in compromising the exercise capacity of normal humans on ascent to high altitude, even to the peak of Mt Everest
TL;DR: Child Behavior Checklists completed by parents of clinically referred American and Dutch boys aged 6-11 and 12-16 were subjected to principal components analyses with varimax rotations and cross-national similarities in the distribution of scores for normative samples supported the use of the same syndrome scales by clinicians and researchers in the two countries.
Abstract: Child Behavior Checklists completed by parents of 1863 clinically referred American and Dutch boys aged 6-11 and 12-16 were subjected to principal components analyses with varimax rotations. For each age group, the construct validity of seven empirically derived syndromes was supported by cross-national correlations ranging from 0.80 to 0.98. These syndromes were designated as Aggressive, Delinquent, Depressed (ages 6-11 only), Hyperactive, Schizoid (ages 12-16 only), Somatic Complaints, Uncommunicative, and Withdrawal (Social Withdrawal for ages 6-11; Hostile Withdrawal for ages 12-16). Cross-national similarities in the distribution of scores for normative samples supported the use of the same syndrome scales by clinicians and researchers in the two countries. The cross-national construct validity of Obsessive-Compulsive and Immature syndromes did not receive adequate support.
TL;DR: Small metal markers are implanted within intervertebral discs and their displacements in response to a complex load (flexion, compression, and anterior shear) are measured radiographically and provide a new class of information concerning the function of the interior of the disc.
Abstract: Small metal markers are implanted within intervertebral discs and their displacements in response to a complex load (flexion, compression, and anterior shear) are measured radiographically These are contrasted to the displacements predicted by a finite element model (FEM) that uses 20 constant-strain triangular elements and is based upon a linear elastic isotropic material The central portion of the disc (nucleus pulposus) moves posteriorly and oppositely to the FEM prediction The anterior and posterior portions of the disc agree more closely with the FEM than the central portions of the disc In general, the FEM predicts much more accurately the up-down displacement components than it does the anterior-posterior components The measured displacements provide a new class of information concerning the function of the interior of the disc, and also provide a new basis for validation of FEMs that attempt to mimic real intervertebral disc behavior Implications for understanding of disc function and pathology are discussed
TL;DR: Etude de l'acidification aerobie par HCl du complexe du titre donnant V IV Cl 2 (SALEN). Voltammetrie cyclique.
Abstract: Etude de l'acidification aerobie par HCl du complexe du titre donnant V IV Cl 2 (SALEN). Voltammetrie cyclique. Structure cristalline de V V O(SALEN)ClO 4
TL;DR: Results above suggest asbestos-induced cell damage is mediated by active oxygen species, and the iron associated with the fiber and/or its interaction with cell membranes might be critical in driving a modified Haber-Weiss (Fenton-type) reaction resulting in production of OH.
TL;DR: This study investigated the response of the spine to both impact and sinusoidal excitation in either a relaxed or erect seated posture, and found the impact method may be a viable replacement for the vibration test method.
Abstract: Low back pain has been shown to occur more frequently among vehicle drivers than in representative control groups. Thus the response of the human to vibration and impact is of interest. This study investigated the response of the spine to both impact and sinusoidal excitation in either a relaxed or erect seated posture. The sinusoidal testing apparatus used was a resonating system consisting of two parallel wooden beams, simply supported, and the impact testing apparatus a bearing-guided, spring-suspended platform, struck from below. Ten subjects (5 males, 5 females) were evaluated using both methods. Transfer functions were compared at 2-4 Hz, 4-8 Hz and 8-16 Hz intervals using a sign test. Although in 24 comparisons of either test method (vibration or impact) or posture (erect or relaxed) where eleven showed differences significant at the p less than .05 level, only 2 out of 24 comparisons were the differences distinct enough to be significant (at the p less than .01 level). Both of these latter differences were due to test method while the subjects were sitting erect. In those instances where there were no significant differences due to test method, the impact method may be a viable replacement for the vibration test method. Where the levels of significance are higher (p less than .01 or p less than .05), further study of the magnitude of the differences is indicated and may reveal further insight into the seated individual as a system.
TL;DR: The results prove that the test tube method for measuring thermal resistance of L. monocytogenes is inaccurate and reports of extraordinary heat resistance based upon this method are correspondingly inaccurate.
TL;DR: In this paper, the vertical profiles of pH were measured at nine shallow water (<5m) locations in Esthwaite Water and 13 littoral sediment cores were horizontally sectioned and sequentially extracted (0.5 M NaHCO3, 0.1 M NaOH, 1 M HCI).
Abstract: SUMMARY. 1. Vertical profiles of pH were measured at nine shallow water (<5m) locations in Esthwaite Water. These indicate strong gradients of pH near the sediment water interface suggesting a marked buffering capacity of the sediments.
2. Thirteen littoral sediment cores were horizontally sectioned and sequentially extracted (0.5 M NaHCO3, 0.1 M NaOH, 1 M HCI) and analysed for soluble reactive phosphorus. The core sections were also analysed for total phosphorus and per cent organic content to determine the vertical and areal variability of phosphorus within the littoral sediments of Esthwaite Water.
3. The rate of release of phosphorus from intact sediment cores was measured in the laboratory as a function of the pH of overlying water, yielding the relationship log K=0.54 pH−3.94, K=mg Pm−2day−1. The maximum release rate measured was 75 mg P m−2 day−2 at pH = 10.5.
4. Experiments on sediment slurries indicate that the release of phosphorus at pH 10 is rapid with approximately 50% of the total NaHCO3+ NaOH extractable phosphorus being released within 3 h.
5. Phosphorus release from the littoral sediments may equal or exceed external sources plus hypolimnetic inputs during periods of high pH associated with times of maximum algal biomass.
TL;DR: The mathematical model indicated that the surface strain for intervertebral discs is verysensitive to the disc‐height: diameter ratio and to fluid loss from the disc but is less sensitive to the helix angle of the fibers.
TL;DR: Studies of the coagulation complex surface-bound enzymes provide insights into the biology of the hemostatic process and may provide ideal models for understanding compartmentalized processes in biology.
TL;DR: This paper examined psychosocial characteristics of 24 preschool-aged siblings of handicapped children in relation to a control group of 22 siblings of non-handicapped children and found no statistically significant differences between groups of children on measures of perceived selfcompetence and acceptance, understanding of developmental disabilities, empathy, and child care responsibility.
Abstract: This project examined psychosocial characteristics of 24 preschool-aged siblings of handicapped children in relation to a control group of 22 siblings of nonhandicapped children. Subjects were matched on family size and income, sibling age, birth order, sex, age spacing, and marital status of their parents. Results indicated no statistically significant differences between groups of children on measures of perceived self-competence and acceptance, understanding of developmental disabilities, empathy, and child care responsibility. Significant group differences were found where brothers of handicapped children were rated by their mothers as being more depressed and aggressive than brothers of nonhandicapped control children. Sisters of handicapped children were rated by mothers as being more aggressive than sisters of nonhandicapped children. Sisters of handicapped children and brothers of nonhandicapped children had significantly fewer privileges and more restrictions on their home activities than other groups. Results are discussed in relation to previous research on older silbings of handicapped children and the general literature on family stress and childhood disability and disease. The importance of examining sibling functioning via multiple measures of child behavior is stressed.
01 Jan 1987
TL;DR: Systematic analysis of the binding of Pyr-Va to PCPS indicated that the binding interaction was characterized by a dissociation constant of 2.7 x 10(-9) M with 42 mol of PCPS bound per mol of Va at saturation.
Abstract: The analysis of free sulfhydryl groups in factor Va using dithiobis-(nitrobenzoic acid) (DTNB) indicated the presence of one accessible thiol in each of the two subunits of the cofactor. Intact factor Va contained one readily accessible sulfhydryl group under native conditions and approximately two such groups after denaturation. A comparison of the rate of modification of the accessible thiol in factor Va under native conditions to those observed with the isolated subunits indicated that the thiol present in component D of the cofactor was readily accessible to reaction with DTNB. Factor Va was reacted with the sulfhydryl-directed fluorophore N-(1-pyrene)maleimide, resulting in the concomitant loss of the accessible thiol with no detectable alteration in the activity of the cofactor. This fluorescent derivative of factor Va (Pyr-Va) was used to examine the binding of factor Va to phospholipid vesicles by fluorescence polarization. Fluorescence polarization of the pyrene moiety increased saturably when Pyr-Va was titrated with increasing concentrations of vesicles composed of phosphatidylcholine and phosphatidylserine (PS). Systematic analysis of the binding of Pyr-Va to PCPS (75% phosphatidylcholine, 25% PS) indicated that the binding interaction was characterized by a dissociation constant of 2.7 x 10(-9) M with 42 mol of PCPS bound per mol of Va at saturation. The data obtained by varying the PS content of the vesicles are consistent with the interpretation that the Va-combining site on the vesicle surface is composed of a discrete number of PS molecules. The binding of Pyr-Va to PCPS was independent of added calcium ion and could be reversed by the addition of unlabeled Va or isolated component E but not by component D. Analysis of the displacement curves indicated that native factor Va or isolated component E and Pyr-Va mutually excluded each other on the vesicle surface with identical affinities. Competition experiments conducted using component E digested by factor Xa or the isolated derivative peptides indicated that the cleavage of component E by factor Xa had no effect on the PCPS binding properties of this subunit. Further, the data obtained with the isolated peptides suggest that the lipid-binding domain of component E is present in the amino-terminal region of this subunit.
TL;DR: The fibrinolytic system comprises a proenzyme, plasminogen, which can be converted to the active enzyme, plAsmin, which degrades fibrin, and inhibition of this system may occur at thelevel of the activators or at the level of generated plasmine.
Abstract: The fibrinolytic system comprises a proenzyme, plasminogen, which can be converted to the active enzyme, plasmin, which degrades fibrin. Plasminogen activation is mediated by plasminogen activators, which are classified as either tissue-type plasminogen activators (t-PA) or urokinase-type plasminogen activators (u-PA). Inhibition of the fibrinolytic system may occur at the level of the activators or at the level of generated plasmin. Plasmin has a low substrate specificity, and when circulating freely in the blood it degrades several proteins including fibrinogen, factor V, and factor VIII. Plasma does, however, contain a fast-acting plasmin inhibitor, alpha 2-antiplasmin, which inhibits free plasmin extremely rapidly but which reacts much slower with plasmin bound to fibrin. A "systemic fibrinolytic state" may, however, occur by extensive activation of plasminogen and depletion of alpha 2-antiplasmin. Clot-specific thrombolysis therefore requires plasminogen activation restricted to the vicinity of the fibrin. Two physiological plasminogen activators, t-PA and single-chain u-PA (scu-PA) induce clot-specific thrombolysis, via entirely different mechanisms, however. t-PA is relatively inactive in the absence of fibrin, but fibrin strikingly enhances the activation rate of plasminogen by t-PA. This is explained by an increased affinity of fibrin-bound t-PA for plasminogen and not by alteration of the catalytic rate constant of the enzyme. The high affinity of t-PA for plasminogen in the presence of fibrin thus allows efficient activation on the fibrin clot, while no significant plasminogen activation by t-PA occurs in plasma. scu-PA has a high affinity for plasminogen (Km = 0.3 microM) but a low catalytic rate constant (kcat = 0.02 sec-1). However, scu-PA does not activate plasminogen in plasma in the absence of a fibrin clot, owing to the presence of (a) competitive inhibitor(s). Fibrin-specific thrombolysis appears to be due to the fact that fibrin reverses the competitive inhibition. The thrombolytic efficacy and fibrin specificity of natural and recombinant t-PA has been demonstrated in animal models of pulmonary embolism, venous thrombosis, and coronary artery thrombosis. In all these studies intravenous infusion of t-PA at sufficiently high rates caused efficient thrombolysis in the absence of systemic fibrinolytic activation. The efficacy and relative fibrinogen-sparing effect of t-PA was recently confirmed in three multicenter clinical trials in patients with acute myocardial infarction.(ABSTRACT TRUNCATED AT 400 WORDS)
TL;DR: Noninfected lizards were dominant in social interactions more often than malarious animals, based on duration and intensity of agonistic encounters toward the other male, and time spent with the female, which hinders the ability of male fence lizards to compete for mates.
Abstract: The effect of malarial parasitism on the ability of male western fence lizards, Sceloporus occidentalis, to compete for access to females was assessed experimentally. Pairs of male lizards, one infected with the malarial parasite, Plasmodium mexicanum, and the other not infected, were matched by size and color and placed in large seminatural outdoor enclosures along with an adult female lizard. Infected males displayed to females and to other males less often than did noninfected male lizards. Noninfected lizards were dominant in social interactions more often than malarious animals, based on duration and intensity of agonistic encounters toward the other male, and time spent with the female. Thus, malarial infection hinders the ability of male fence lizards to compete for mates.
TL;DR: The authors' observations reveal that the ergatoid males are morphologically and behaviorally highly specialized for fighting, and regularly engage in lethal combat with one another so that there is typically only a single ergatoids male per nest.
Abstract: In most ant species, males are winged and disperse from their maternal nests on nuptial flights prior to mating [1]. However, in a small but diverse minority of ant genera, wingless and highly worker-like (ergatoid) males have evolved; and some species produce both winged and ergatoid males [2]. Little is known about the reproductive biology of many of these species, but if ergatoid males mate then they must do so in or near their maternal nest, a situation which could provoke intensive reproductive competition among males [3]. Ergatoid males of one ponerine ant species are known to fight one another, apparently in this context [3]. Colonies of the myrmicine ant, Cardiocondyla wroughtonii (Forel), frequently have multiple queens (polygyny) and produce both winged and ergatoid males [4, 5]. Our observations reveal that the ergatoid males are morphologically and behaviorally highly specialized for fighting, and regularly engage in lethal combat with one another so that there is typically only a single ergatoid male per nest. In contrast, winged males never appear to fight, and often coexist in large numbers with a resident ergatoid male. In the laboratory, both types of males mate within their nests with the young winged (alate) queens
TL;DR: Application of germicidal teat dips appeared to have selectively altered both prevalence and distribution of Staphylococcus species intramammary infections.
TL;DR: The results indicate that the Alzheimer's disease cells, unlike normal cells, fail to repair methyl‐methane sulfonate–induced DNA damage, and both normal and Alzheimer’s disease cells are able to ameliorate the effects of ultraviolet light.
Abstract: The most common cause of senile and presenile dementia is Alzheimer's disease, a disorder with an undetermined cause. A number of studies have indicated that neurons from patients with Alzheimer's disease have decreased ribonucleic acid levels and reduced protein synthesis. Recent studies using lymphoblasts from patients with Alzheimer's disease have indicated that these cells are more sensitive to deoxyribonucleic acid (DNA)–alkylating agents. We have used cell survival, unscheduled DNA synthesis, and alkaline elution to assess the capacity for DNA repair in skin fibroblasts from normal control subjects, control subjects with central nervous system disease, and patients with Alzheimer's disease. Our results indicate that the Alzheimer's disease cells, unlike normal cells, fail to repair methyl-methane sulfonate–induced DNA damage. Both normal and Alzheimer's disease cells are able to ameliorate the effects of ultraviolet light. These results indicate that a specific pathway for DNA repair is affected in Alzheimer's disease. The repair defect may be related to the cause of the disease or may be the cause of the disease.
TL;DR: A significant proportion of the InsP3 extracted from thrombin-stimulated platelets under neutral conditions is resistant to Ins(1,4,5)P3 3-kinase but susceptible after acid treatment, implying the presence of inositol 1,2-cyclic 4,5-trisphosphate (Ins (1,2cyc4, 5)P 3).
TL;DR: Predipping reduced the rate of intramammary infection with major mastitis pathogens approximately 54% and infection rate with esculin-positive streptococci and coliforms was reduced more than 51%.