cssi/SciSciGPT-SciSciNet huggingface dataset:
Differential Forms and Tensors

In the previous chapter, we emphasized the central role of the tangent space in differential geometry. The tangent space at a point is a set whose elements, tangent vectors, arise from calculus in at least two equivalent ways. We have also seen examples of how nonlinear geometric objects can arise from an object defined pointwise at the algebraic level of the tangent spaces. For example, vector fields give rise to more global geometric objects such as integral curves and diffeomorphisms. The passage from the algebraic tangent spaces to the geometric space in these examples was a process of “integration.”
α Particles as Probes of Nuclear Shape in the Rare Earths and Structure Effects on Proton Emission in the Mass-80 Region

Low-emission barriers and large subbarrier anisotropies in the α-particle decay, with respect to the spin direction, of Sn and rare-earth compound nuclei are examined in the light of recent calculations incorporating deformation. For the rare-earth systems deformation which increases with spin is necessary to explain the data. Energy spectra and angular correlations of evaporated protons from the 52Cr(34S, 2p2n)82Sr reaction were measured in coincidence with discrete transitions. Large changes in the shape of the proton spectra were observed when high-spin states in different rotational bands are populated. These effects cannot be explained by phase space arguments that do not include explicitly structure in the deexcitation process. They are interpreted as resulting from near-yrast to near-yrast stretched proton emission, which preferentially populates the yrast band by subbarrier protons.
Classical and generalized Horton laws for peak flows in rainfall-runoff events

The discovery of the Horton laws for hydrologic variables has greatly lagged behind geomorphology, which began with Robert Horton in 1945. We define the classical and the generalized Horton laws for peak flows in rainfall-runoff events, which link self-similarity in network geomorphology with river basin hydrology. Both the Horton laws are tested in the Iowa River basin in eastern Iowa that drains an area of approximately 32 400 km2 before it joins the Mississippi River. The US Geological Survey continuously monitors the basin through 34 stream gauging stations. We select 51 rainfall-runoff events for carrying out the tests. Our findings support the existence of the classical and the generalized Horton laws for peak flows, which may be considered as a new hydrologic discovery. Three different methods are illustrated for estimating the Horton peak-flow ratio due to small sample size issues in peak flow data. We illustrate an application of the Horton laws for diagnosing parameterizations in a physical rainfall-runoff model. The ideas and developments presented here offer exciting new directions for hydrologic research and education.
Chapter 14: landmarks of surgical neurology and the interplay of disciplines.

Abstract The specialty of surgical neurology developed out of general surgery in the second half of the 19th century. It was aided by the development of general anesthetics, the advent of aseptic methods, and the emerging theory of cortical localization of function. This chapter examines the history of “modern” brain surgery, the leaders in this pursuit, and the landmarks that changed when and how these surgeries were conducted. It is stressed that the surgeries conducted by Broca, Macewen, Godlee, Horsley and others not only saved lives and ultimately created a new field, but also contributed to the basic sciences, fostering an improved understanding of the functional organization of the brain.
Changing Perceptions of Diversity and Oppression: MSW Students Discuss the Effects of a Required Course

Meeting the Council on Social Work Education's standards related to diversity content poses unique demands for faculty, who may encounter student resistance and heightened classroom emotions. This article reports on data gathered from the self-reports of 43 MSWstudents enrolled in a required course on diversity and oppression in the fall 1994 semester. The authors analyze barriers to student learning about the effects of social identity and discrimination, and make recommendations for curriculum development and classroom teaching.
Peptide bond formation by in vitro selected ribozymes

An attractive solution to the problem of the origin of protein synthesis in an evolving ‘RNA world’ involves catalysis by nucleic acid without assistance from proteins1,2. Indeed, even the modern ribosome has been considered to be fundamentally an RNA machine3, and the large ribosomal subunit can carry out peptidyl transfer in the absence of most of its protein subunits4. Successive cycles of in vitro selection and amplification5,6,7 have been used to find RNAs that perform many biochemical reactions8,9,10,11,12,13,14,15,16, including transfer of an RNA-linked amino acid to their own 5′-amino-modified terminus15. Here we demonstrate the in vitro selection of ribozymes (196 nucleotides) that perform the same peptidyl transferase reaction as the ribosome: that is, they can join amino acids by a peptide bond. Like ribosome substrates, one amino acid (N-blocked methionine) is esterified to the 3′(2′)-O of adenosine, whereas the acceptor amino acid (phenylalanine) has a free amino group. Our best characterized ribozyme recognizes the amino-acid ester substrate by binding its adenosine moiety, and is therefore capable of utilizing Leu- and Phe- as well as Met-derived substrates. Such lack of specificity with respect to the amino acid is a feature necessary for a generalized protein-synthesizing enzyme.
Targeting Pink1-Parkin-Mediated Mitophagy for Treating Liver Injury

Alcoholic liver disease and acetaminophen overdose are common causes of severe liver disease and liver failure in the United States for which there is no cure. Therefore, development of new therapeutic strategies for treatment of liver injury caused by acetaminophen and alcohol is needed. We demonstrated that autophagy protects against alcohol and acetaminophen-induced liver injuries by removing damaged mitochondria via mitophagy, which is a selective form of autophagy specific for degradation of damaged mitochondria. Parkin is well-known to be required for mitophagy induction in in vitro models, and we previously showed that the Parkin-mediated mitophagy pathway likely plays a protective role against alcohol and acetaminophen-induced liver injuries. Therefore, pharmacological upregulation of the Parkin-mediated mitophagy pathway in the liver may provide a novel and effective therapeutic option for treatment of acetaminophen and alcohol-induced liver injuries. In this review, we discuss regulation of Parkin-mediated mitophagy and possible therapeutic targets of intervention in this pathway.
Magueijo-Smolin Transformation as a Consequence of a Specific Definition of Mass,Velocity, and the Upper limit on Energy

We consider an alternative approach to double special-relativistic theories. The point of departure is not �-deformed algebra (or even grouptheoretical considerations) but rather 3 physical postulates defining particle’s velocity, mass, and the upper bound on its energy in terms of the respective classical quantities. For a specific definition of particle’s velocity we obtain Magueijo-Smolin (MS) version of the double special-relativistic theory. It is shown that this version follows from the �-Poincare algebra by the appropriate choice of on the shell mass , such that it is always less or equal Planck’s mass. The �-deformed Hamiltonian is found which invalidates the recent arguments about unphysical predictions of the MS transformation.
Non-linear mixture model and application for enhanced resolution multispectral classification

A new mixture model based on a probabilistic formulation is described. The model is non-linear, and unlike previous mixture models, does not need to be inverted to compute mixtures from spectra. Instead, mixtures are estimated using an interpolation approach. There are no constraints between the number of bands and endmembers. The mixture model is used to enhance the spatial resolution of classification images-increasing the classification accuracy by about 20% in the example presented. The enhanced resolution classifier is better able to detect features near the resolution of the sensor, to identify subtle patterns not fully resolved in the original data, and to more precisely delineate the boundaries of areal features.
Muscarinic receptor reserve for inhibition of cAMP accumulation in bovine trachealis cells

In airway smooth muscle, muscarinic agonists inhibit synthesis of adenosine 3',5'-cyclic monophosphate (cAMP). The goal was to characterize the relationship between agonist occupancy of muscarinic receptors and regulation of cAMP for bovine trachealis cells. For intact cells dispersed by enzyme, carbachol maximally inhibited 58 +/- 4% (mean +/- SE, n = 5) of isoproterenol-stimulated cAMP accumulation at low concentrations [log half-maximal effective concentration (EC50) = -8.34 +/- 0.16]. In radioligand binding experiments, carbachol competed for [3H]quinuclidinyl benzilate (n = 7) and [N-methyl-3H]scopolamine (n = 3) binding sites on intact cells with both low (log KL = -4.26 +/- 0.06 and -4.50 +/- 0.20, respectively) and high affinities (log KH = -5.91 +/- 0.24 and -6.39 +/- 0.19, respectively). In separate experiments, a fraction of the muscarinic receptors on intact cells were inactivated with either phenoxybenzamine (POB) or propylbenzylcholine mustard (PBCM). We compared equally effective concentrations of carbachol before and after partial inactivation of receptors, and the calculated equilibrium dissociation constants for agonist (log KA = -4.36 +/- 0.42 to -3.20 +/- 0.40 for POB; log KA = -4.27 +/- 0.45 for PBCM) were much greater than the half-maximally effective concentration of carbachol in control cells (log EC50 = -8.34 +/- 0.16). Based on these equilibrium dissociation constants, we calculated that maximum responses (EC95) to carbachol were obtained by occupancy of 0.8% of the receptors coupled to cAMP regulation. We concluded that muscarinic inhibition of cAMP accumulation is characterized by a muscarinic receptor reserve.
Comparative analyses of proteins from Haemophilus influenzae biofilm and planktonic populations using metabolic labeling and mass spectrometry

Non-typeable H. influenzae (NTHi) is a nasopharyngeal commensal that can become an opportunistic pathogen causing infections such as otitis media, pneumonia, and bronchitis. NTHi is known to form biofilms. Resistance of bacterial biofilms to clearance by host defense mechanisms and antibiotic treatments is well-established. In the current study, we used stable isotope labeling by amino acids in cell culture (SILAC) to compare the proteomic profiles of NTHi biofilm and planktonic organisms. Duplicate continuous-flow growth chambers containing defined media with either “light” (L) isoleucine or “heavy” (H) 13C6-labeled isoleucine were used to grow planktonic (L) and biofilm (H) samples, respectively. Bacteria were removed from the chambers, mixed based on weight, and protein extracts were generated. Liquid chromatography-mass spectrometry (LC-MS) was performed on the tryptic peptides and 814 unique proteins were identified with 99% confidence. Comparisons of the NTHi biofilm to planktonic samples demonstrated that 127 proteins showed differential expression with p-values ≤0.05. Pathway analysis demonstrated that proteins involved in energy metabolism, protein synthesis, and purine, pyrimidine, nucleoside, and nucleotide processes showed a general trend of downregulation in the biofilm compared to planktonic organisms. Conversely, proteins involved in transcription, DNA metabolism, and fatty acid and phospholipid metabolism showed a general trend of upregulation under biofilm conditions. Selected reaction monitoring (SRM)-MS was used to validate a subset of these proteins; among these were aerobic respiration control protein ArcA, NAD nucleotidase and heme-binding protein A. The present proteomic study indicates that the NTHi biofilm exists in a semi-dormant state with decreased energy metabolism and protein synthesis yet is still capable of managing oxidative stress and in acquiring necessary cofactors important for biofilm survival.
Convergence of RNA cis Elements and Cellular Polyadenylation Factors in the Regulation of Human Cytomegalovirus UL37 Exon 1 Unspliced RNA Production

The human cytomegalovirus (HCMV) UL36-38 immediate early (IE) locus encodes proteins required for its growth. The UL37 promoter drives production of an unspliced and several alternatively spliced RNAs. The UL37 exon 1 (UL37x1) unspliced RNA is abundant from IE to late times of HCMV infection, whereas the UL37 spliced RNAs are markedly less abundant. Production of the UL37x1 unspliced RNA requires polyadenylation (PA) at nucleotide 50998, which lies within intron 1, upstream of the UL37 exon 2 (UL37x2) acceptor. The physical proximity of its cis elements suggests steric hindrance between PA and splicing machineries for UL37 pre-mRNA. To test this possibility, we generated site-specific mutants in Target 1 PA and RNA splicing cis elements and compared the PA and splicing efficiencies of mutant RNAs with those of wild-type RNA. The mutually exclusive processing events of UL37x1 PA and UL37x1-UL37x2 splicing have been accurately recapitulated in transfected permissive human fibroblasts (HFFs) expressing a Target 1 minigene RNA, which contains the required splicing and PA cis elements. Two mutants in the invariant PA signal dramatically decreased UL37x1 PA as expected and, concomitantly, increased the efficiency of UL37x1-UL37x2 RNA splicing. Consistent with these results, changes to consensus UL37x1 donor and UL37x2 acceptor sites increased the efficiency of UL37x1-UL37x2 RNA splicing but decreased the efficiency of UL37x1 PA. Moreover, HCMV infection of HFFs increased the abundance of the PA cleavage stimulatory factor CstF-64, the potent splicing suppressor PTB, and the hypophosphorylated form of the splicing factor SF2 at 4 h postinfection. Induction of these factors further favors production of the UL37x1 unspliced RNA over that of the spliced RNAs. Taken together, these results suggest that there is a convergence in UL37 RNA regulation by cis elements and cellular proteins which favors production of the UL37x1 unspliced RNA during HCMV infection at the posttranscriptional level.
Silylformylation of Carbonyl Compounds: A Study of Substrate, Catalyst, and Reaction Conditions

This paper presents a study of the rhodium-catalyzed silylformylation [Rh(I) precatalyst, PhMe2SiH, THF, carbon monoxide (15−1500 psig), 23 °C] of aldehydes. This new catalytic homologation reaction produces α-(silyloxy) aldehydes in a highly efficient manner. Rhodium(I) appears to be the optimum transition metal for the catalytic process. The reaction is optimized at carbon monoxide pressures over 50 psig. It appears that PhMe2SiH is the silane reagent of choice. The silylformylation of carbonyl compounds is very general for aldehyde substrates (aromatic, heterocyclic, alkyl, and ferrocenyl: 16 examples presented) and can tolerate the presence of internal alkene and alkyne, ester, and acyclic ketone functional groups. Aldehydes with α-substituents show moderately good diastereoselectivity, producing the syn-α-(silyloxy) aldehyde (10 to 20:1, syn:anti) as the major product. Ketone substrates possessing β-hydrogens yield only silyl enol ether without concomitant hydrosilylation coproducts. Imine substrate...
Rabies in Bats from Alabama

Data on rabies virus infection in bats that were submitted to the Alabama Department of Public Health from 1995-2005 were analyzed. Demographic factors, such as species and sex, and temporal aspects, such as yearly and monthly trends, were investigated. Thirteen species of bats were submitted, and of those, individuals from seven species were rabid; prevalence was highest in Lasiurus borealis and Pipistrellus subflavus and lowest in Eptesicus fuscus and Nycticeius humeralis. There was no difference in prevalence of rabies between sexes or years. Statistically, more rabid bats were submitted in August, September, and November; and fewer were submitted in March, June, and July. Results were similar to those from other regions of North America; these data from Alabama can help to present a more complete view of rabies in bats in North America.
Differences in Populating First Year Seminars and the Impact on Retention and Course Effectiveness.

The purpose of this study was to examine the relationship between the methods by which first year seminars are populated at a large research institution and the impact on student retention and the ...
Finite state homomorphic sequential systems

Because many systems of practical interest fall outside the scope of linear theory it is desirable to enlarge as much as possible the class of systems for which a complete structure theory is available. In this paper a class of finite state sequential systems evolving in groups is considered. The concepts of controllability, observability, minimality, realizability, and the isomorphism of minimal realizations are developed. Results which are analogous to - but differ in essential details from - those of linear system theory are derived. These results are potentially useful in such diverse areas as algorithmic design and algebraic coding.
Neuronotypic differentiation results in reduced levels and altered distribution of synaptophysin in PC12 cells.

Abstract: Several synaptic vesicle proteins including synap-tophysin and p65/synaptotagmin are expressed by the pheochromocytoma cell line PC12. Stimulation of these cells with nerve growth factor for 7 days induces morphologic neuronotypic differentiation, but the levels of synaptophysin are markedly reduced. Stimulation with cyclic AMP analogs also produces neuronotypic differentiation of PC12 cells, and the degree of morphologic differentiation induced by these agents parallels their ability to effect reduction in synaptophysin levels. By contrast, levels of p65/synaptotagmin are increased following neuronotypic differentiation. The contrasting effects of neuronotypic differentiation on levels of synaptophysin and p65/synaptotagmin indicate potential differences in the regulation of these proteins in PC12 cells. Immunocytochemical labeling of undifferentiated PC12 cells reveals concentrations of synaptophysin in the perinuclear region. After neuronotypic differentiation, there is reduction in perinuclear labeling and concentration of label in swellings along PC12 cell processes. At the ultra-structural level, synaptophysin labeling is found on similar organelles in both undifferentiated and nerve growth factor-stimulated PC12 cells. Although the highest labeling densities were seen on small clear vesicles, specific labeling was also seen on dense core vesicles. The presence of synaptophysin on both small clear vesicles and dense core vesicles indicates potential functional similarities in these vesicle types. The changes in the levels and immunocytochemical distribution of synaptophysin after neuronotypic differentiation suggest possible functional heterogeneity among morphologically similar populations of small clear vesicles.
Altered zinc homeostasis and hepatic accumulation of metallothionein in indomethacin-induced enteropathy

Abstract Altered zinc homeostasis is one of several metabolic sequelae of inflammation wherein zinc is redistributed to the liver from endogenous sources such as plasma and sequestered in hepatic metallothionein. Studies were performed in rats to determine the effect(s) of indomethacin, a potent ulcerogenic agent, on zinc metabolism. A single sc dose of indomethacin given to fed rats in amounts between 1 and 10 mg/100 g body wt produced, by 24 hr, profound hypozincemia, greater intestinal absorption of zinc, induction of hepatic metallothionein synthesis, and gastrointestinal lesions. These responses were significantly muted when the drug was administered to fasted rats. Results indicate that the effects of indomethacin on zinc homeostasis are associated with drug-induced enteropathy. Furthermore, results provide evidence that hepatic metallothionein functions, at least in part to sequester zinc in pathophysiologic conditions.
Conditional median survival of patients with advanced carcinoma: surveillance, epidemiology, and end results data.

BACKGROUND Conditional survival is clinically useful, particularly for patients with malignant disease who have a poor prognosis. However, there are no published data on the conditional median survival of patients with advanced carcinoma on a population basis. METHODS Data on 217,573 patients with breast, colorectal, lung, or prostate carcinoma who were newly diagnosed with distant disease between 1973 and 1995 and who were followed through the end of 1997 were extracted from the Surveillance, Epidemiology, and End Results (SEER) data base of the National Cancer Institute. The Kaplan–Meier method was employed to estimate conditional median survival and 95% confidence intervals at 0–5 years after the initial diagnosis. RESULTS The conditional median survival increased as time elapsed after the initial diagnosis. The increase was slowest and almost leveled off among patients with prostate carcinoma. The median survival of patients with breast carcinoma increased relatively linearly with time, i.e., 5–6 months per year. Conversely, there was a rapid increase in the conditional median survival according to the amount of time since diagnosis for patients with lung and colorectal carcinoma. The trend was most pronounced for patients with colorectal carcinoma. At 5 years after the initial diagnosis, the remaining median survival was longest for patients with colorectal carcinoma, almost 6 years (71.5 months), followed by patients with lung carcinoma (52.5 months), breast carcinoma (42.5 months), and prostate carcinoma (34.5 months). Although race was a correlate with initial survival, gender and age had more impact on late conditional survival. CONCLUSIONS The conditional median survival provides useful and encouraging information for patients who survive with advanced disease and for healthcare professionals who treat these patients. However, the information should be used carefully, taking the limitations of these data into account. Cancer 2001;92:2211–9. © 2001 American Cancer Society.
Effect of temperature on spermatogenesis, on the production and action of androgens and on the ultrastructure of gonadotropic cells in the lizard Anolis carolinensis

Adult male lizards (Anolis carolinensis) were kept at either 31° or 20°C for 11 weeks starting December 4, and the activity of the pituitary-gonadal axis was monitored by examination of pituitaries, testes, androgen target organs and plasma testosterone levels. The gonadotropic cells of both thermal groups were stimulated to secrete for approximately seven weeks. Thereafter, the cells of 31°C animals indicated reduced secretion and increased granule storage, while those at 20°C became hyperactive. Testes enlarged at both temperatures: testicular enlargement at 31°C was due to active spermatogenesis and sperm production, whereas at 20°C, gametogenesis was largely blocked at the spermatocyte level, and enlargement was due to accumulation of cells, growth, and hydration. Leydig cells were larger and more numerous at 31° Epididymal and kidney tubules (androgen target organs) increased in diameter and epithelial height at both temperatures, but responses were markedly greater at 31° Also, male-male aggressive behavior occurred only at the higher temperature; dominant lizards had slightly higher testosterone levels than subordinates. In contrast, plasma testosterone levels were consistently higher (> 2-fold) at 20°. Thus the production of gonadotropins in Anolis is stimulated at 20° in late winter, and these hormones promote androgen production but not spermatogenesis. The high androgen level at 20°C evokes only a limited response in epididymis and renal sex tubules, and it neither inhibits the gonadotropic cells of the pituitary nor produces aggressive behavior. These results demonstrate that constituent processes in the pituitary-gonadal system have different sensitivities to temperature and that thermal effects may be misinterpreted by standard histological or histometric analysis of gonads and accessory sexual structure.
Doxapram in hypercapnic chronic obstructive pulmonary with respiratory failure

An 81-yr-old man with severe chronic obstructive pulmonary disease and hypercapnia presented to the emergency department (ED) obtunded and in acute respiratory distress. He had instructed his family to refuse intubation but agreed to all other measures to sustain his life. Treatment measures included the administration of intravenous doxapram, which was followed promptly by a marked improvement in his respiratory function and mentation. Respiratory stimulants may be useful as a temporizing measure in this difficult ED therapeutic problem.
EXPECTATIONS, INTEREST RATES, AND COMMERCIAL BANK STOCKS

This study examines the effect of current and expected interest rate changes on bank equity values and attempts to reconcile the conflicting findings of previous research regarding this issue. A multiple index market model of bank security returns is specified and estimated. The results confirm the existence of an interest rate effect on bank stocks that is not explained by returns on the market portfolio. In addition, bank stock returns appear to be sensitive to an interest rate forecast error.
Design of circularly polarized ultra-wideband aperiodic antenna arrays

For simplicity, most ultra-wideband aperiodic array layout design approaches use only isotropic sources as elements during optimization. However, since the selected antenna element can have a large impact on the total radiation pattern of the final array, it would be beneficial in such cases to use realistic antenna element patterns when designing array layouts. In this paper, a realistic spiral antenna is used in the design of aperiodic ultra-wideband antenna arrays with special attention paid not only to peak sidelobe level but axial ratio as well. The covariance matrix adaption evolutionary strategy is utilized together with an efficient pattern multiplication technique to optimize the locations and rotational configuration of spiral elements in 75-element arrays. A method of moments solver is employed to validate the optimized designs.
Dengue Fever: A Bibliometric Analysis of India’s Contributions to the Research Literature of This Dangerous Tropical Disease

Dengue is a mosquito-borne infectious tropical disease that has a particularly adverse impact on India. A bibliometric analysis disclosed that India has one of the most prominent records in the world in terms of output of dengue articles and citations to them. Indians are frequently research collaborators with scientists from other countries affected by the disease, with a significant number of the resulting articles being published in Indian journals and subsequently well cited. Internationally more prominent journals published in the United States, the United Kingdom, or Germany dominate as venues for the 10 most-cited dengue-related papers overall.
The developmental basis of adult arrhythmia: atrial fibrillation as a paradigm

Normal cardiac rhythm is one of the most fundamental physiologic phenomena, emerging early in the establishment of the vertebrate body plan. The developmental pathways underlying the patterning and maintenance of stable cardiac electrophysiology must be extremely robust, but are only now beginning to be unraveled. The step-wise emergence of automaticity, AV delay and sequential conduction are each tightly regulated and perturbations of these patterning events is now known to play an integral role in pediatric and adult cardiac arrhythmias. Electrophysiologic patterning within individual cardiac chambers is subject to exquisite control and is influenced by early physiology superimposed on the underlying gene networks that regulate cardiogenesis. As additional cell populations migrate to the developing heart these too bring further complexity to the organ, as it adapts to the dynamic requirements of a growing organism. A comprehensive understanding of the developmental basis of normal rhythm will inform not only the mechanisms of inherited arrhythmias, but also the differential regional propensities of the adult heart to acquired arrhythmias. In this review we use atrial fibrillation as a generalizable example where the various factors are perhaps best understood.
Melatonin: Receptor-mediated events that may affect breast and other steroid hormone–dependent cancers

Epidemiological studies have suggested a possible link between extremely low frequency electromagnetic fields (EMFs) and increased rates of certain cancers. One cancer that has been postulated to be associated with EMF exposure is breast cancer, for which increased rates have been reported among electricians. These cancer associations are weak, and the link to EMF exposures remains tenuous. Understanding the mechanisms by which EMFs could have biological effects will help in elucidating the risk, if any, from EMFs. One hypothesis that has received considerable attention involves reduction of melatonin levels by EMFs. This hypothesis suggests that loss of melatonin affects a variety of hormonal processes such as estrogen homeostasis and thereby may increase breast cancer rates. Since this theory was first presented, putative melatonin receptors have been cloned, providing new tools with which to examine melatonin's mechanism of action and the melatonin hypothesis. These receptors are found in nuclear and membrane fractions of cells. The nuclear receptors (retinoid Z receptors) are found both in the brain and in non-neural tissues, whereas the membrane-bound receptors are found primarily in neural tissue and have a higher affinity for melatonin. These receptors may control a variety of hormonal and immunological functions, including the release of gonadotropins from the hypothalamus and pituitary and 5-lipoxygenase activity in B lymphocytes. This Working Hypothesis briefly reviews our current knowledge of melatonin receptors and then provides theories on how the inactivation of melatonin receptors may cause cancer and suggests areas of research for addressing this question. Mol. Carcinog. 21:149–155, 1998. © 1998 Wiley-Liss, Inc.
An actin subdomain 2 mutation that impairs thin filament regulation by troponin and tropomyosin.

Striated muscle thin filaments adopt different quaternary structures, depending upon calcium binding to troponin and myosin binding to actin. Modification of actin subdomain 2 alters troponin-tropomyosin-mediated regulation, suggesting that this region of actin may contain important protein-protein interaction sites. We used yeast actin mutant D56A/E57A to examine this issue. The mutation increased the affinity of tropomyosin for actin 3-fold. The addition of Ca2+ to mutant actin filaments containing troponin-tropomyosin produced little increase in the thin filament-myosin S1 MgATPase rate. Despite this, three-dimensional reconstruction of electron microscope images of filaments in the presence of troponin and Ca2+ showed tropomyosin to be in a position similar to that found for muscle actin filaments, where most of the myosin binding site is exposed. Troponin-tropomyosin bound with comparable affinity to mutant and wild type actin in the absence and presence of calcium, and in the presence of myosin S1, tropomyosin bound very tightly to both types of actin. The mutation decreased actin-myosin S1 affinity 13-fold in the presence of troponin-tropomyosin and 2.6-fold in the absence of the regulatory proteins. The results suggest the importance of negatively charged actin subdomain 2 residues 56 and 57 for myosin binding to actin, for tropomyosin-actin interactions, and for regulatory conformational changes in the actin-troponin-tropomyosin complex.
Jinnealogy: Everyday life and Islamic theology in post-Partition Delhi

In this article I explore what I call jinnealogy , a theological orientation that emerges when the genealogies of human memory are confronted with the amnesic forces of an obliterated landscape. In stories told in contemporary Delhi, long-lived jinn act as transmitters connecting human beings centuries apart in time. In petitions deposited to jinn -saints in a ruined medieval palace, medieval ideas of justice come together with modern bureaucratic techniques. Both stories and rituals attest to a theological newness intricately entwined with the transformations of the postcolonial city’s spiritual and physical landscapes. Jinn are present in the blank spaces of the map, where the plans of the bureaucracy, the verdicts of the judiciary, and the illegibility of the post-Partition Indian state coincide to attempt vast erasures of the city’s Muslim landscapes. Jinnealogy, the supersession of human chains of memory by the long lives of the jinn, challenges the magical amnesia of the state by bringing up other temporalities, political theologies, and modes of witnessing against the empty, homogenous time of a bureaucratically constituted present.
Chebyshev expansion on intervals with branch points with application to the root of Kepler's equation: A Chebyshev-Hermite-Padé method

When two or more branches of a function merge, the Chebyshev series of u(@l) will converge very poorly with coefficients a"n of T"n(@l) falling as O(1/n^@a) for some small positive exponent @a. However, as shown in [J.P. Boyd, Chebyshev polynomial expansions for simultaneous approximation of two branches of a function with application to the one-dimensional Bratu equation, Appl. Math. Comput. 143 (2002) 189-200], it is possible to obtain approximations that converge exponentially fast in n. If the roots that merge are denoted as u"1(@l) and u"2(@l), then both branches can be written without approximation as the roots of (u-u"1(@l))(u-u"2(@l))=u^[email protected](@l)[email protected](@l). By expanding the nonsingular coefficients of the quadratic, @b(@l) and @c(@l), as Chebyshev series and then applying the usual roots-of-a-quadratic formula, we can approximate both branches simultaneously with error that decreases proportional to exp([email protected]) for some constant @s>0 where N is the truncation of the Chebyshev series. This is dubbed the ''Chebyshev-Shafer'' or ''Chebyshev-Hermite-Pade'' method because it substitutes Chebyshev series for power series in the generalized Pade approximants known variously as ''Shafer'' or ''Hermite-Pade'' approximants. Here we extend these ideas. First, we explore square roots with branches that are both real-valued and complex-valued in the domain of interest, illustrated by meteorological baroclinic instability. Second, we illustrate triply branched functions via roots of the Kepler equation, f(u;@l,@e)[email protected](u)[email protected]=0. Only one of the merging roots is real-valued and the root depends on two parameters (@l,@e) rather than one. Nonetheless, the Chebyshev-Hermite-Pade scheme is successful over the whole two-dimensional parameter plane. We also discuss how to cope with poles and logarithmic singularities that arise in our examples at the extremes of the expansion domain.
Effects of acute ethanol administration on female rat liver as a function of aging

Abstract Female Fischer 344 rats, aged 4, 14, and 25 months, received 4.0 g/kg of ethanol by intraperitoneal (i.p.) injection. Blood alcohol concentrations 2.5, 6 and 16 hr after ethanol injection were similar in the three age groups. Hepatic glutathione (GSH) levels were diminished 6 hr after ethanol injection, and there were no age-dependent differences in the depleted levels (3.2 ± 0.1, 3.5 ± 0.2, and 3.0 ± 0.5 μ g GSH/g liver). However, GSH contents in livers of young-adult rats approached control levels after 16 hr, whereas they remained depressed in older rats. Serum levels of hepatic enzymes were significantly elevated 6 hr after ethanol administration. The increases were greater in middle-aged and old rats than in young-adult rats. The results suggest that middle-aged and old rats are more susceptible than young rats to the acute toxicity of ethanol.
The role of databases in support of computational chemistry calculations

A role for electronic structure databases in assisting users of quantum chemistry applications select better model parameters is discussed in light of experiences gained from a software prototype known as the Computational Chemistry Input Assistant (CCIA). It is argued that the ready availability of information pertaining to the applications and theoretical models can substantially increase the likelihood of novice users obtaining the desired accuracy from their calculations while simultaneously making better use of computer resources. Expert users, who find themselves contemplating studies in new areas of research, may also benefit from the proposed tools. For maximum impact, this assistance should be provided while users are actively engaged in preparing calculations. © 1996 by John Wiley & Sons, Inc.
Fish Intake and Risk of Incident Atrial Fibrillation

Background— Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is particularly common in the elderly. Although effects of fish intake, including potential antiarrhythmic effects, may favorably influence risk of AF, relationships between fish intake and AF incidence have not been evaluated. Methods and Results— In a prospective, population-based cohort of 4815 adults ≥age 65 years, usual dietary intake was assessed at baseline in 1989 and 1990. Consumption of tuna and other broiled or baked fish correlated with plasma phospholipid long-chain n-3 fatty acids, whereas consumption of fried fish or fish sandwiches (fish burgers) did not. AF incidence was prospectively ascertained on the basis of hospital discharge records and annual electrocardiograms. During 12 years’ follow-up, 980 cases of incident AF were diagnosed. In multivariate analyses, consumption of tuna or other broiled or baked fish was inversely associated with incidence of AF, with 28% lower risk with intake 1 to 4 t...
Effects of exogenous cortisol on the GH/IGF-I/IGFBP network in channel catfish.

Abstract Glucocorticoids are known to hinder somatic growth in a number of vertebrate species. In order to better understand the mechanisms through which they may act in channel catfish, we examined the effects of feeding cortisol on the growth hormone (GH)/insulin-like growth factor-I (IGF-I)/IGF-binding protein (IGFBP) network. Fish (30.6 ± 3.0 g) were fed once daily for 4 weeks and treatments included: (1) High-cortisol (dietary cortisol provided at 400 mg/kg feed), (2) Low-cortisol (dietary cortisol provided at 200 mg/kg feed), and (3) Control (commercial catfish feed). Fish fed diets with cortisol weighed approximately 50% less than Controls. Feed intake was reduced by approximately 30% in both treatments of cortisol fed fish compared to Controls. A ∼20-kDa IGFBP was observed in plasma from High- and Low-treated fish while it was not detected in Control fish plasma. High-cortisol treatment increased pituitary GH mRNA expression approximately 10-fold while liver IGF-I mRNA expression was not different between cortisol-treated fish and Controls. Cortisol treatments decreased plasma levels of IGF-I. These data indicate that feeding cortisol for 4 weeks reduces weight gain, feed intake, and plasma levels of IGF-I and induces a ∼20-kDa IGFBP. One mechanism through which cortisol may impede growth of catfish is through an increase in a low molecular weight IGFBP which may lead to inhibitory effects on the action of IGF-I.
Gadolinium Chloride-Induced Hepatocyte Proliferation Is Prevented by Antibodies to Tumor Necrosis Factor α

Gadolinium chloride (GdCl(3)) destroys large Kupffer cells and has been used extensively in mechanistic studies in a number of disease and toxicity processes; however, it cannot be used to study hepatocyte turnover since it increases cell proliferation itself. The mechanism by which GdCl(3) activates cell turnover in liver is unknown, but several possibilities exist. Here it was demonstrated that a direct mitogenic action on hepatocytes is unlikely since GdCl(3) did not stimulate the growth of primary rat hepatocyte in vitro. Therefore, it was hypothesized that GdCl(3) acts indirectly through mitogenic cytokines of nonparenchymal cell origin. Antibodies to tumor necrosis factor alpha (TNFalpha) were used to evaluate if TNFalpha is causally responsible for GdCl(3)-induced cell proliferation. GdCl(3) treatment of rats in vivo increased hepatocyte replication 5-fold in 24 h and 3-fold in 48 h. Pretreatment with specific anti-TNFalpha antibodies completely prevented these effects. However, when antibody treatment was delayed until 24 h after GdCl(3), increased cell proliferation was not prevented, suggesting that TNFalpha production during the first 24 h after treatment is responsible for activation of a signaling cascade involving other mitogens that sustain hepatocyte replication at 48 h. Twenty-four hours after treatment with GdCl(3), TNFalpha mRNA transcripts were increased 2-fold over control, an effect that was prevented by pretreatment with anti-TNFalpha antibody. NFkappaB, which is known to be involved in TNFalpha transcription, was activated by GdCl(3) about 4.5-fold over control 8 h after treatment in vivo, an increase not observed when antibodies to TNFalpha were present. When GdCl(3) was added to macrophages in culture, TNFalpha was nearly doubled 4 h after treatment. Additionally, conditioned media harvested from macrophages treated with GdCl(3) for 2 to 8 h stimulated the growth of HepG2 cells in culture about 2-fold, while antibodies to TNFalpha completely prevented this effect. Taken together, these data are consistent with the hypothesis that TNFalpha released from Kupffer cells at early time points prior to their destruction is causally responsible for triggering a cascade of events responsible for GdCl(3)-induced cell proliferation.
Protease-mediated human smooth muscle cell proliferation by urokinase requires epidermal growth factor receptor transactivation by triple membrane signaling

Abstract Background Urokinase (uPA) modulates cellular and extracellular matrix responses within the microenvironment of the vessel wall and has been shown to activate the epidermal growth factor receptor (EGFR). This study examines the role of the protease domain of uPA during EGFR activation in human vascular smooth muscle cells (VSMC). Methods Human coronary VSMC were cultured in vitro. Assays of cell proliferation and EGFR phosphorylation were examined in response to the carboxyterminal fragment of uPA (CTF) in the presence and absence of the plasmin, metalloprotease and a disintegrin and metalloproteinase (ADAM) inhibitors, heparin-bound epidermal growth factor (HB-EGF), and EGFR inhibitors, and small interfering RNA to EGFR and ADAMs. Results CTF produced a dose-dependent increase in DNA synthesis and cell proliferation in human VSMC, which was blocked in a dose-dependent manner by both plasmin inhibitors and the EGFR inhibitor, AG1478. CTF induced time-dependent EGFR phosphorylation, which was blocked by inhibitors of plasmin and metalloproteinases activity. The presence of urokinase plasminogen activator receptor was not required. Inhibition of ADAM-10 and -12, and of HB-EGF blocked EGFR activation in response to CTF. CTF-mediated activation of EGFR was mediated through Gβγ, src, and NAD(P)H oxidase. Conclusions In human coronary VSMC, uPA induces uPAR-independent, domain-dependent smooth muscle cell proliferation through transactivation of EGFR by a plasmin-mediated, ADAM-induced, and HB-EGF–dependent process, which is mediated by the intracellular pathways involving Gαi, Gβγ, src, and NAD(P)H oxidase.
Theory of transport in liquid metals. II. Calculation of shear viscosity coefficients

Abstract A hard sphere model, previously developed for a theory of self-diffusion in liquid metals, is extended to the calculation of viscosity coefficients of these materials. The basic assumption of the theory is that the viscosity coefficient of a liquid metal is equal to that of a hard-fluid under the same conditions of temperature and number density. The important elements of the theory are a way of estimating the hard-sphere diameter of a metal atom as a function of temperature, the use of the Enskog theory to estimate the viscosity coefficient of a hard sphere fluid, and the use of correction factor to correct for the errors in the Enskog theory. The correction factor is obtained in two different ways, from molecular dynamics calculations for the hard-sphere fluid and from a corresponding-states principle based on analysis of experimental viscosity data. The two resulting theories are compared with experiment for a variety of metals and the agreement is found to be very good except for elements that are not sufficiently metallic.
Growth factor-heparan sulfate "switches" regulating stages of branching morphogenesis.

The development of branched epithelial organs, such as the kidney, mammary gland, lung, pancreas, and salivary gland, is dependent upon the involvement and interaction of multiple regulatory/modulatory molecules, including soluble growth factors, extracellular matrix components, and their receptors. How the function of these molecules is coordinated to bring about the morphogenetic events that regulate iterative tip-stalk generation (ITSG) during organ development remains to be fully elucidated. A common link to many growth factor-dependent morphogenetic pathways is the involvement of variably sulfated heparan sulfates (HS), the glycosaminoglycan backbone of heparan sulfate proteoglycans (HSPG) on extracellular surfaces. Genetic deletions of HS biosynthetic enzymes (e.g., C5-epimerase, Hs2st), as well as considerable in vitro data, indicate that variably sulfated HS are essential for kidney development, particularly in Wolffian duct budding and early ureteric bud (UB) branching. A role for selective HS modifications by enzymes (e.g., Ext, Ndst, Hs2st) in stages of branching morphogenesis is also strongly supported for mammary gland ductal branching, which is dependent upon a set of growth factors similar to those involved in UB branching. Taken together, these studies provide support for the notion that the specific spatio-temporal HS binding of growth factors during the development of branched epithelial organs (such as the kidney, mammary gland, lung and salivary gland) regulates these complex processes by potentially acting as “morphogenetic switches” during the various stages of budding, branching, and other developmental events central to epithelial organogenesis. It may be that two or more growth factor-selective HS interactions constitute a functionally equivalent morphogenetic switch; this may help to explain the paucity of severe branching phenotypes with individual growth factor knockouts.
Capacity planning in manufacturing and computer networks

Abstract This paper addresses capacity planning in manufacturing and computer networks. More specifically, given a manufacturing or computer system modeled as a network of queues, we consider the minimum cost selection of capacity levels from a discrete set of choices such that a single system performance constraint is satisfied. We focus on settings where the cost of obtaining capacity is a concave function, allowing fixed charges and economies of scale to be handled. To solve this class of capacity planning problems, we present a branch and bound algorithm that globally minimizes a concave cost function over a single convex nonlinear performance constraint and lower and upper bounds on the discrete capacity variables. We also present reoptimization procedures that allow the subproblems to be solved more efficiently. Computational results with the algorithm are reported.