Showing papers by "University of Utah published in 1985"
TL;DR: Resource availability in the environment is proposed as the major determinant of both the amount and type of plant defense, and theories on the evolution of plant defenses are compared with other theories.
Abstract: The degree of herbivory and the effectiveness of defense varies widely among plant species. Resource availability in the environment is proposed as the major determinant of both the amount and type of plant defense. When resource are limited, plants with inherently slow growth are favored over those with fast growth rates; slow rates in turn favor large investments in antiherbivore defenses. Leaf lifetime, also determined by resource availability, affects the relative advantages of defenses with different turnover rates. Relative limitation of different resources also constrains the types of defenses. The proposals are compared with other theories on the evolution of plant defenses.
3,601 citations
Book•
01 Jan 1985TL;DR: For a variety of sociopolitical, economic, scientific, and clinical reasons, considerable interest in the study of father-child relationships has emerged in the last decade as mentioned in this paper, and the focus has narrowed to concern about the effects of increased paternal involvement.
Abstract: For a variety of sociopolitical, economic, scientific, and clinical reasons, considerable interest in the study of father-child relationships has emerged in the last decade. In the last few years, the focus has narrowed to concern about the effects of increased paternal involvement. Interest in, and concern about, the latter seems to be especially prominent among social service providers and clinicians. For this reason, and also because the voluminous literature on paternal influences has been scrutinized quite extensively, we will focus in this chapter on evidence concerning the effects of increased involvement. Much less will be said, mostly in summary fashion, about paternal influences more generally, although readers will be referred to recent reviews for further discussions of the literature.
2,279 citations
TL;DR: Evidence is summarized that supports the hypothesis that A and T nucleotides are favored at all locations in the D. yakuba mtDNA molecule where these nucleotide are compatible with function.
Abstract: The sequence of the 16,019 nucleotide-pair mitochondrial DNA (mtDNA) molecule ofDrosophila yakuba is presented. This molecule contains the genes for two rRNAs, 22 tRNAs, six identified proteins [cytochrome b, cytochrome c oxidase subunits I, II, and III (COI-III), and ATPase subunits 6 and 8] and seven presumptive proteins (URF1-6 and URF4L). Replication originates within a region of 1077 nucleotides that is 92.8% A+T and lacks any open reading frame larger than 123 nucleotides. An equivalent to the sequence found in all mammalian mtDNAs that is associated with initiation of second-strand DNA synthesis is not present inD. yakuba mtDNA. Introns are absent fromD. yakuba mitochondrial genes and there are few (0–31) intergenic nucleotides. The genes found inD. yakuba and mammalian mtDNAs are the same, but there are differences in their arrangement and in the relative proportions of the complementary strands of the molecule that serve as templates for transcription. Although theD. yakuba small and large mitochondrial rRNA genes are exceptionally low in G and C and are shorter than any other metazoan rRNA genes reported, they can be folded into secondary structures remarkably similar to the secondary structures proposed for mammalian mitochondrial rRNAs.D. yakuba mitochondrial tRNA genes, like their mammalian counterparts, are more variable in sequence than nonorganelle tRNAs. In mitochrondrial protein genes ATG, ATT, ATA, and in one case (COI) ATAA appear to be used as translation initiation codons. The only termination codon found in these genes is TAA. In theD. yakuba mitochondrial genetic code, AGA, ATA, and TGA specify serine, isoleucine, and tryptophan, respectively. Fifty-nine types of sense codon are used in theD. yakuba mitochondrial protein genes, but 93.8% of all codons end in A or T. Codon-anticodon interactions may include both G-A and C-A pairing in the wobble position. Evidence is summarized that supports the hypothesis that A and T nucleotides are favored at all locations in theD. yakuba mtDNA molecule where these nucleotides are compatible with function.
1,436 citations
TL;DR: The sequence of the entire RNA genome of the type flavivirus, yellow fever virus, has been obtained and implies that mature viral proteins are produced by posttranslational cleavage of a polyprotein precursor and has implications for flaviv virus RNA replication and for the evolutionary relation of this virus family to other RNA viruses.
Abstract: The sequence of the entire RNA genome of the type flavivirus, yellow fever virus, has been obtained. Inspection of this sequence reveals a single long open reading frame of 10,233 nucleotides, which could encode a polypeptide of 3411 amino acids. The structural proteins are found within the amino-terminal 780 residues of this polyprotein; the remainder of the open reading frame consists of nonstructural viral polypeptides. This genome organization implies that mature viral proteins are produced by posttranslational cleavage of a polyprotein precursor and has implications for flavivirus RNA replication and for the evolutionary relation of this virus family to other RNA viruses.
933 citations
TL;DR: In this paper, the gravitational quasi-normal frequencies of both stationary and rotating black holes are calculated by constructing exact eigensolutions to the radiative boundary-value problem of Chandrasekhar and Detweiler.
Abstract: The gravitational quasi-normal frequencies of both stationary and rotating black holes are calculated by constructing exact eigensolutions to the radiative boundary-value problem of Chandrasekhar and Detweiler. The method is that employed by Jaffe in his determination of the electronic spectra of the hydrogen molecule ion in 1934, and analytic representations of the quasi-normal mode wavefunctions are presented here for the first time. Numerical solution of Jaffe’s characteristic equation indicates that for each l -pole there is an infinite number of damped Schwarzschild quasi-normal modes. The real parts of the corresponding frequencies are bounded, but the imaginary parts are not. Figures are presented that illustrate the trajectories the five least-damped of these frequencies trace in the complex frequency plane as the angular momentum of the black hole increases from zero to near the Kerr limit of maximum angular momentum per unit mass, a = M , where there is a coalescence of the more highly damped frequencies to the purely real value of the critical frequency for superradiant scattering.
894 citations
TL;DR: Five new omega-conotoxins that block presynaptic calcium channels are described, and the fact that they inhibit sequential steps in neuromuscular transmission suggests that their action is synergistic rather than additive.
Abstract: To paralyze their more agile prey, the venomous fish-hunting cone snails (Conus) have developed a potent biochemical strategy. They produce several classes of toxic peptides (conotoxins) that attack a series of successive physiological targets in the neuromuscular system of the fish. The peptides include presynaptic omega-conotoxins that prevent the voltage-activated entry of calcium into the nerve terminal and release of acetylcholine, postsynaptic alpha-conotoxins that inhibit the acetylcholine receptor, and muscle sodium channel inhibitors, the mu-conotoxins, which directly abolish muscle action potentials. These distinct peptide toxins share several common features: they are relatively small (13 to 29 amino acids), are highly cross-linked by disulfide bonds, and strongly basic. The fact that they inhibit sequential steps in neuromuscular transmission suggests that their action is synergistic rather than additive. Five new omega-conotoxins that block presynaptic calcium channels are described. They vary in their activity against different vertebrate classes, and also in their actions against different synapses from the same animal. There are susceptible forms of the target molecule in peripheral synapses of fish and amphibians, but those of mice are resistant. However, the mammalian central nervous system is clearly affected, and these toxins are thus of potential significance for investigating the presynaptic calcium channels.
715 citations
690 citations
TL;DR: A comprehensive review of relaxation processes in semi-crystalline polymers is presented in this paper, with emphasis placed on phase origin, phase properties and the effects of the interactions between the crystal and amorphous phases.
522 citations
TL;DR: This article found that on average, fathers spend 25 to 35% as much time as mothers do in direct interaction with their children, with maternal-child interaction dominated by caretaking and father-child inter? action characterized by play.
Abstract: malian species. The authors describe several studies designed to determine how much time fathers spend with their children and how this compares with the extent of involvement by mothers. On average, fathers spend 25 to 35% as much time as mothers do in direct interaction with their children. Factors affecting the degree of paternal involvement are then described. These factors include: Motivation, skills, support, and institutional practices. Researchers have demonstrated that human fathers can be as competent as mothers, although lack of practice leads over time to lower levels of competence than evinced by mothers. Mothers and fathers behave differently in interaction with their children, with maternal-child interaction dominated by caretaking and father-child inter? action characterized by play.
519 citations
TL;DR: In this article, the experimental facts concerning relaxation processes in semi-crystalline polymers have been reviewed and progress in interpretation of the molecular processes underlying the relaxations is considered.
461 citations
TL;DR: Patients able to tolerate low-dose pulse MTX therapy were significantly improved, compared with patients receiving placebo therapy, for all clinical variables measured, including joint pain/tenderness and swelling counts, rheumatoid nodules, and patient and physician assessment of disease activity.
Abstract: One hundred eighty-nine patients with rheumatoid arthritis were entered into a prospective, controlled, double-blind multicenter trial comparing placebo and methotrexate (MTX). One hundred ten patients completed 18 weeks of therapy. No remissions were seen, but patients able to tolerate low-dose pulse MTX therapy were significantly improved, compared with patients receiving placebo therapy, for all clinical variables measured, including joint pain/tenderness and swelling counts, rheumatoid nodules, and patient and physician assessment of disease activity. MTX treatment demonstrated statistically significant improvement over placebo in patients with anemia, elevated erythrocyte sedimentation rate, and rheumatoid factor. However, nearly one-third of the patients receiving MTX were withdrawn for adverse drug reactions, of which elevated levels of liver enzymes was the most common. Pancytopenia occurred in 2 patients taking MTX. All adverse drug effects resolved without sequelae. MTX appears to be effective in the treatment of active rheumatoid arthritis but requires close monitoring for toxicity.
TL;DR: Endothelial cell-generated PAF, a potent activator of platelets and neutrophils with endothelial cells, may mediate some of the inflammatory properties of histamine and bradykinin and be a factor in the formation of a thrombogenic vascular surface.
Abstract: Cultured human endothelial cells synthesize prostacyclin (PGI2), a potent inhibitor of platelet function, when stimulated with histamine, bradykinin, or ATP. Paradoxically, we report that these agonists also induced the rapid and sustained synthesis of platelet-activating factor (PAF) by endothelial cells. In fact, the synthesis of this potent activator of platelets and neutrophils was induced by stimulation of the same receptor subtype that induced PGI2 synthesis: stimulation of a histamine H1 or a bradykinin B2 receptor induced both PAF and PGI2 synthesis. However, two physiologically important differences exist between the production of PAF and PGI2 by endothelial cells. The synthesis of PGI2 proceeded for only 7.5 min before the abrupt termination of synthesis, whereas the synthesis of PAF was clearly detectable even 45 min after stimulation. Although maximal accumulation of PAF occurred after 10-15 min of stimulation, the prolonged synthesis resulted in the presence of PAF for up to 1 h after stimulation. Secondly, whereas PGI2 was released from the cell monolayer, PAF remained cell-associated without significant release to the external medium. Endothelial cell-generated PAF, therefore, does not function as a hormone. The prolonged association of this potent activator of platelets and neutrophils with endothelial cells may mediate some of the inflammatory properties of histamine and bradykinin. It may also be a factor in the formation of a thrombogenic vascular surface, an event suggested to play a primary role in the pathogenesis of thrombosis and atherosclerosis.
TL;DR: Evidence for tight linkage between the CF locus and a DNA sequence polymorphism at the met oncogene locus is obtained, which places theCF locus in the middle third of the long arm of chromosome 7, probably between bands q21 and q31.
Abstract: Cystic fibrosis is a recessive genetic disorder, characterized clinically by chronic obstructive lung disease, pancreatic insufficiency and elevated sweat electrolytes; affected individuals rarely live past their early twenties. Cystic fibrosis is also one of the most common genetic diseases in the northern European population. The frequency of carriers of mutant alleles in some populations is estimated to be as high as 1 in 20, carrying a concomitant burden of about one affected child in 1,500 births. Because little is known of the essential biochemical defect caused by the mutant gene, a genetic linkage approach based on arbitrary genetic markers and family studies is indicated to determine the chromosomal location of the cystic fibrosis (CF) gene. We have now obtained evidence for tight linkage between the CF locus and a DNA sequence polymorphism at the met oncogene locus. This evidence, combined with the physical localization data for the met locus presented in the accompanying paper1, places the CF locus in the middle third of the long arm of chromosome 7, probably between bands q21 and q31.
TL;DR: Using the major peptide (GIIIA) in electrophysiological studies on nerve-muscle preparations and in single channel studies using planar lipid bilayers, it is established that the toxin blocks muscle sodium channels, while having no discernible effect on nerve or brain sodium channels.
TL;DR: In Gegenwart von DCC und von Dimethylaminopyridin (DMAP)-hydrochlorid (II) in die Lactone (III) uberfuhren as mentioned in this paper.
Abstract: ω-Hydroxysauren (I) lassen sich in verdunnter Losung in Gegenwart von DCC und von Dimethylaminopyridin (DMAP)-Hydrochlorid (II) in die Lactone (III) uberfuhren.
TL;DR: The endothelial cell-dependent stimulation of PMN adherence by thrombin is demonstrated, a novel mechanism of enhanced leukocyte adherence that may be important in interactions between the coagulation and inflammatory systems.
Abstract: Highly purified human thrombin stimulates the adherence of polymorphonuclear leukocytes (PMNs) to vascular endothelial cells (EC). When Indium-labeled PMNs were incubated with primary monolayers of cultured human umbilical vein EC, the basal adherence was 10 +/- 1% of the PMNs at 5 min. Addition of thrombin (2 U/ml) increased the mean adherence to 42 +/- 15%. Enhanced neutrophil adherence in response to thrombin was confirmed by experiments with unlabeled leukocytes, examined by phase contrast and scanning electron microscopy. The action of thrombin was on the EC, since it did not directly stimulate PMN adhesiveness when measured by aggregation or by adherence to nylon fiber columns. Furthermore, enhanced neutrophil adherence occurred when endothelial monolayers were treated with thrombin and washed before adding 111Indium (111In)-labeled PMNs. Thrombin that had been inactivated with antithrombin III and heparin did not enhance neutrophil adherence. Prothrombin, Factor Xa, and fibrinogen were also ineffective. The stimulated adherence of PMNs was maximal 5 min after incubation of the EC with thrombin, and decreased thereafter. The response was dose-dependent, with half-maximal stimulation at 0.2-0.25 U thrombin/ml. The enhanced PMN adherence caused by thrombin may result in part from the production of platelet-activating factor (PAF) by the stimulated EC since thrombin-stimulated EC synthesize PAF with a time course and concentration dependence that are similar to the time and concentration relationships for thrombin-stimulated PMN adherence, PAF itself promoted neutrophil adherence to the EC monolayers, and pretreatment of PMNs with PAF decreased the adherence stimulated by thrombin and PAF, but not adherence stimulated by N-formylmethionyl-leucyl-phenylalanine and C5a fragments, which indicates specific desensitization of PAF-mediated adherence. These studies demonstrate the endothelial cell-dependent stimulation of PMN adherence by thrombin, a novel mechanism of enhanced leukocyte adherence that may be important in interactions between the coagulation and inflammatory systems.
TL;DR: These studies support the intracellular degradation of PEC as the principal pathway of degradation once the molecular weight of the aged polymer is reduced to 3000 or less.
Abstract: Poly(epsilon-caprolactone) [PEC], a biodegradable aliphatic polyester, undergoes a two-stage degradation process: The first lengthy phase involves nonenzymatic hydrolytic cleavage of ester groups, the second phase beginning when the polymer is more highly crystalline, and of low molecular weight. The cellular events of the second phase were examined by implanting gelatin capsules containing 25 mg of low molecular weight (Mn 3000) PEC powders, 106 to 500 micron, in rats. PEC fragments ultimately were degraded in phagosomes of macrophages and giant cells, the process requiring less than 13 days for completion at some sites. PEC was also identified within fibroblasts. These studies support the intracellular degradation of PEC as the principal pathway of degradation once the molecular weight of the aged polymer is reduced to 3000 or less.
TL;DR: The most complete early hominid skeleton ever found was discovered at Nariokotome III, west Lake Turkana, Kenya, and excavated in situ in sediments dated close to 1.6 Myr.
Abstract: The most complete early hominid skeleton ever found was discovered at Nariokotome III, west Lake Turkana, Kenya, and excavated in situ in sediments dated close to 1.6 Myr. The specimen, KNM-WT 15000, is a male Homo erectus that died at 12 ± 1 years of age, as judged by human standards, but was already 1.68 m tall. Although human-like in many respects, this specimen documents important anatomical differences between H. erectus and modern humans for the first time.
TL;DR: It is proposed that metallothionein ligates Ag(I) and Cu(I)" in a trigonal geometry by bridging thiolates" in contradistinction to a tetrahedral binding geometry in the M7-protein.
Journal Article•
TL;DR: D dopamine plays an important role in the changes mediated by the administration of methamphetamine in both the dopaminergic and serotonergic systems, and the ability of a single administrations of methamphetamine to depress tryptophan hydroxylase was also dependent on catecholamine synthesis.
Abstract: Multiple administrations of high doses of methamphetamine to rats cause long-term depression of both dopamine and serotonin synthesis. Coadministration of the catecholamine synthesis inhibitor, alpha-methyl-p-tyrosine, antagonizes this effect of methamphetamine on both neurotransmitter systems. However, when catecholamine synthesis was maintained by the administration of L-dopa and the peripheral decarboxylase inhibitor R04-4602, alpha-methyl-p-tyrosine no longer prevented the effects of methamphetamine on either dopamine or serotonin synthesis. In addition, the administration of the specific dopamine uptake blocker, amfonelic acid, significantly attenuated the changes in the serotonin synthesizing enzyme, tryptophan hydroxylase, resulting from multiple high doses of methamphetamine. The ability of a single administration of methamphetamine to depress tryptophan hydroxylase was also dependent on catecholamine synthesis. These results suggest that dopamine plays an important role in the changes mediated by the administration of methamphetamine in both the dopaminergic and serotonergic systems.
TL;DR: The authors examined the stock price reaction around the announcement of proposed changes in long-term managerial compensation packages and found that on average these plans are met with positive market reactions, i.e., shareholder wealth increases.
TL;DR: DNA markers and sampling of three-generation families can be used to construct complete linkage maps of human chromosomes, important in mapping disease loci and in determining the genetic or environmental component of a disease.
Abstract: DNA markers and sampling of three-generation families can be used to construct complete linkage maps of human chromosomes. This is important in mapping disease loci and in determining the genetic or environmental component of a disease.
TL;DR: The most important environmental factors influencing the composition of trace fossil assemblages in marine settings are bathymetry, substrate, oxygen and hydrodynamic energy as discussed by the authors, which are closely interrelated.
15 Oct 1985-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the authors report the details of the design, operation and performance of the University of Utah Fly's Eye detector which was built to record the passage of ultra-high energy cosmic rays through the atmosphere via atmospheric fluorescence.
Abstract: We report the details of the design, operation and performance of the University of Utah Fly's Eye detector which was built to record the passage of ultra-high energy cosmic rays through the atmosphere via atmospheric fluorescence. Emphasized in the presentation are (1) light production by charged particles in the atmosphere, (2) kinematics of an EAS as seen by the Fly's Eye, (3) signal to noise considerations and its impact on detector design, (4) details of detector hardware and software, (5) detector calibration, (6) techniques employed in measurement of shower longitudinal development profiles and primary particle energy, and (7) assessment of detector performance by a comparison of Monte Carlo and real data distributions.
TL;DR: Functional evaluation on follow-up (functional class, San Diego questionnaire and exercise time) all tended to favor those receiving BB, and low-dose BB is tolerated in 80% of IDC patients on a long-term basis.
Abstract: Beta-blockade therapy to improve survival in idiopathic dilated cardiomyopathy (IDC) has been both advocated and criticized. However, randomized studies have not been performed. Thus, 50 patients with IDC were randomized in pairs to standard therapy (C) alone or with beta blockade (BB). Beta-blockade therapy with metoprolol was titrated from 12.5 to 50 mg twice daily as tolerated (final average dose, 61 mg/day). Groups were comparable in age (C, 50 +/- 15 years; BB, 51 +/- 13 years), gender (C, 76% male; BB, 56% male), entry functional class (C, 2.8 +/- 0.8; BB, 2.7 +/- 0.7), and left ventricular ejection fraction (C, 27 +/- 12%; BB, 29 +/- 10%). Follow-up averaged 19 months (range 1 to 38). One subject in each group was lost to follow-up. There were 3 early BB dropouts (within 2 days) due to low-output syndrome (2 patients) or fatigue (1 patient). Eleven patients died. By intention to treat, 5 BB and 6 C patients died (difference not significant). By actual treatment, 3 BB patients died, including 2 late dropouts (at 0.2, 10 and 17 months), and 8 C patients died (at 2, 9, 9, 15, 18, 24, 29 and 32 months, p = 0.12). In additional, functional evaluation on follow-up (functional class, San Diego questionnaire and exercise time) all tended to favor those receiving BB. Low-dose BB is tolerated in 80% of IDC patients on a long-term basis. Those continuing to take BB have a good prognosis. Mortality in C patients, however, is less than in some retrospective studies.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: This work discusses each of the oviposition decisions in light of natural selection theory to illustrate the utility of understanding the selective forces acting on ovipositing females.
Abstract: Ovipositing insects face at least four decisions: 1) what hosts to utilize, 2) where to search for them, 3) what clutch size, and 4) what sex ratio to produce on a host. Historically, study of these phenomena has focused on elucidating the proximate causes of observed behaviors. However, as originally outlined by N. Tinbergen, three other “causes” are also important in fully understanding any pattern of behavior. These are ontogenetic, phylogenetic, and ultimate (or natural selection) causes. Here we advocate study of all four types of causation, viewing them as complementary. We then discuss each of the oviposition decisions in light of natural selection theory to illustrate the utility of understanding the selective forces acting on ovipositing females.
TL;DR: The characteristics and magnitude of these responses were quite similar to those observed in the previous study of the effects of PGE2 on weanling rats except for the delayed increase in cortico-endosteal bone formation.
Abstract: To assess the efficacy of PGE2 in inducingin vivo bone formation, graded doses of prostaglandins E2 were administered to 255 g rats. Histomorphometric analyses of selected sequential fluorescent-labeled bones of rats treated with 0,0.3, 1.0, 3, or 6 mg PGE2/kg/d for 21 days showed that the doses of PGE2 depressed longitudinal bone growth, increased growth cartilage thickness slightly, decreased degenerative cartilage cell size and cartilage cell production slightly, and increased proximal tibial metaphyseal hard-tissue mass markedly. Periosteal bone formation was depressed at the higher doses, and an early, slight depression in endosteal bone formation was also observed, along with a striking late increase in endosteal bone formation and in the formation of trabecular bone in the marrow cavity of the tibial shaft. The characteristics and magnitude of these responses were quite similar to those observed in our previous study of the effects of PGE2 on weanling rats except for the delayed increase in cortico-endosteal bone formation.
TL;DR: The diagnosis of attention deficit disorder, residual type, should be considered in patients with prominent complaints of impulsivity, restlessness, emotional lability, and hot temper who do not suffer from schizophrenia or major mood disorder and do not have symptoms of schizotypal or borderline personality disorders.
Abstract: Thirty-seven adult patients meeting the Utah criteria for attention deficit disorder, residual type, were entered into a double-blind crossover trial of methylphenidate and placebo. A moderate-to-marked therapeutic response occurred in 21 (57%) of the patients while receiving methylphenidate and in four (11%) while receiving placebo, a highly significant difference statistically and clinically. The responding patients showed significant improvement in the following areas: attentional difficulty, motor overactivity, affective lability, and impulsivity. The diagnosis of attention deficit disorder, residual type, should be considered in patients with prominent complaints of impulsivity, restlessness, emotional lability, and hot temper who do not suffer from schizophrenia or major mood disorder and do not have symptoms of schizotypal or borderline personality disorders.
TL;DR: In this paper, a free radical (or "one-electron") methodology for carbon-carbon bond forming reactions using allylstannanes is described in detail, which has the advantages of tolerating quite complex functionality in the substrate and of being nearly stoichiometric in reagents, and not requiring extensive experimentation for application to new substrates.
TL;DR: In this article, the authors present data on the forest activities of Ache women that show that differences in parental investment partially account for variation in food acquisition among individual women, and also suggest that childcare constraints are important in understanding the sexual division of labor.
Abstract: Anthropologists have frequently proposed that sexual division of labor is produced by childcare constraints on women's subsistence work. We present data on the forest activities of Ache women that show that differences in parental investment partially account for variation in food acquisition among individual women. Data also suggest that childcare constraints are important in understanding the sexual division of labor.