cssi/SciSciGPT-SciSciNet huggingface dataset:
Ultrastructure of the Corpus Luteum of the Cycling Mare

Corpora lutea of 12 cycling pony mares were studied by electron microscopy on Days 3, 9 and 15 after ovulation. In the early part of the secretory phase (Day 3), luteal cells were fully luteinized and contained numerous lipid droplets, round to elongate mitochondria with tubular cristae, perinuclear Golgi elements, dense bodies, multivesicular bodies and regions of extensively developed smooth endoplasmic reticulum (SER). On Day 9, luteal cells contained few lipid droplets, round to pleomorphic mitochondria with tubular cristae, dispersed Golgi elements, increased numbers of dense bodies, rare multivesicular bodies and an increased complement of SER. Decreased numbers of lipid droplets and hypertrophy of the SER correlated with known peak progesterone levels associated with Day 9. By Day 15, luteal cells displayed symptoms of degeneration including rarefied and swollen mitochondria, condensed whorls of SER, vesiculated SER, irregular or pycnotic nuclei, accumulations of pale lipid droplets, myelin figures and autophagic vacuoles. j3-glycogen particles were interspersed between SER cisternae in all time periods studied. Rarefied mitochondria were observed in otherwise nondegenerate cells and since mitochondrial enzymes catalyze the rate limiting step in progesterone synthesis, it is suggested that mitochondrial disruption may be an efficient way to terminate luteal progesterone synthesis.
Convolutional reconstruction algorithm for fan beam concave and convex circular detectors

A modified convolution-backprojection reconstruction algorithm for a circular detector with an arbitrary radius of curvature has been derived for fan-beam geometries. The algorithm reduces to conventional fan-beam algorithms for flat detectors and for curved detectors having whose radii of curvature coincident with the X-ray tube focal spot. The algorithm substitutes a power series of convolution integrals in place of a single convolution integral. Computer simulations have verified the validity of the algorithm for a detector that curves away from the X-ray source. In this case, it has been demonstrated that good reconstructions are obtained when only a few of the terms of the power series are retained. The development of this algorithm represents a first step toward a cone-beam reconstruction algorithm that eventually will be used for an image-intensifier-based computerized-tomography volume imager being developed in the authors' laboratory. >
Comparing the overlapping of two independent confidence intervals with a single confidence interval for two normal population parameters

Two overlapping confidence intervals have been used in the past to conduct statistical inferences about two population means and proportions. Several authors have examined the shortcomings of Overlap procedure and have determined that such a method distorts the significance level of testing the null hypothesis of two population means and reduces the statistical power of the test. Nearly all results for small samples in Overlap literature have been obtained either by simulation or by formulas that may need refinement for small sample sizes, but accurate large sample information exists. Nevertheless, there are aspects of Overlap that have not been presented and compared against the standard statistical procedure. This article will present exact formulas for the maximum % overlap of two independent confidence intervals below which the null hypothesis of equality of two normal population means or variances must still be rejected for any sample sizes. Further, the impact of Overlap on the power of testing the null hypothesis of equality of two normal variances will be assessed. Finally, the noncentral t-distribution is used to assess the Overlap impact on type II error probability when testing equality of means for sample sizes larger than 1.
Phase Transitions in Lattice Gases of Hard-Core Molecules Having Two Orientations

A number of hard-core lattice gases in which a lattice site can be occupied by a molecule in either of two possible orientations are proved to undergo order-disorder phase transitions. Examples include lattice gases of trigonal planar molecules on a triangular lattice, tetrahedral molecules on a bodycentered cubic lattice, and linear molecules on a square lattice.
Nanophase Separation in Monodisperse Rodcoil Diblock Polymers

The authors have observed nanophase-separated structures in rodcoil polymers synthesized in their laboratory. Each polymer consists of a perfectly monodisperse, rodlike segment covalently bonded to a coil like segment of polyisoprene such that both rod and coil share the same molecular backbone. The polyisoprene was prepared by living anionic polymerization, and thus the rodcoil diblock molecules in the systems studied are of fairly uniform molar mass. Annealing of solution-cast thin films approximately 5--10 nm thick leads to ordered nanoscale morphologies that depend upon the volume fraction of rod segments in these diblock molecules. The authors find by transmission electron microscopy that the morphology varies from alternating strips of rod- and coil-rich domains to discrete aggregates of rods arranged in a hexagonal superlattice as rod volume fraction is decreased. At an intermediate volume fraction the authors see a coexistence of strips and aggregates. This breakup of rod domains may be the result of entropic coil stretching penalties analogous to those postulated recently by Williams and Fredrickson in lamellar assemblies of rodcoils.
DIVALENT CATIONS AND THE ELECTROSTATIC POTENTIAL AROUND DNA : MONTE CARLO AND POISSON-BOLTZMANN CALCULATIONS

The predictions of counterion condensation theory for divalent ions were tested by comparison with the results of Monte Carlo calculations on an all-atom model of DNA. Monovalent–divalent competition at the polyelectrolyte surface was investigated by varying the partial molar volume of divalent ions. To assess the viability of using Poisson–Boltzmann (PB) calculations for determining divalent ion concentrations at DNA surfaces, Monte Carlo (MC) calculations were compared with PB calculations using different models of the dielectric continuum. It was determined that, while standard PB calculations of divalent ion surface densities are about 25–30% below those predicted by MC techniques, and somewhat larger than errors previously determined for monovalent ions, errors due to the use of the mean-field approximation of PB theory are smaller than those arising from common assumptions regarding the dielectric continuum. © 1999 John Wiley & Sons, Inc. Biopoly 49: 575–590, 1999
Self-reorganization of mixed poly(methyl methacrylate)/polystyrene brushes on planar silica substrates in response to combined selective solvent treatments and thermal annealing

Abstract This article reports reversible changes in surface morphology and surface wettability of mixed poly(methyl methacrylate) (PMMA)/polystyrene (PS) brushes with PS Mn slightly lower than that of PMMA in response to combined selective solvent treatments and thermal annealing. The mixed brushes were synthesized from asymmetric difunctional initiator-terminated monolayers by controlled radical polymerizations. Two sets of experiments were performed. The first set involved treating the samples with glacial acetic acid (AA), a selective solvent for PMMA, followed by treatment with cyclohexane, a selective solvent for PS, or thermal annealing. The surfaces were rough and composed of relatively ordered nanodomains after AA treatment. Subsequent cyclohexane treatment or thermal annealing made the surfaces flattened and surface analysis indicated that the outermost layers were occupied by PS. The second set of experiments involved treating the samples with cyclohexane or thermal annealing, followed by AA treatment. The surfaces were smooth after cyclohexane treatment or thermal annealing and became very rough in the subsequent AA treatment. The nanodomains formed in AA treatment were speculated to be micelles with PS forming the core shielded by PMMA chains.
Word Clouds: An Informal Assessment of Student Learning

Word clouds are visual displays of texts, such that the frequency of a word used in a text is represented by the size of the word in a word cloud. These are recognized as useful teaching tools (Ber...
The regenerative response of single mature muscle fibers isolated in vitro.

Abstract Segments of individual differentiated muscle fibers, ranging from 1–10 mm in length, were dissected from the pectoral muscle of juvenile Japanese quail and cultured for periods ranging up to 2–3 weeks under conditions known to promote the proliferation and eventual differentiation of embryonic myoblasts. Approximately 22% of such fibers give rise to a colony of bipolar cells which expands in area and cell number. Sometime during the second or third week the process of myoblast fusion is initiated and a network of long cross-striated multinuclear cells is formed. In the vast majority of fibers the colony arises from only one highly localized site along the fiber suggesting that proliferative competence is restricted to extremely few fiber nuclei. This same conclusion is suggested, as well, by the observation that fiber degeneration, in terms of the loss of intact nuclei, occurs rapidly and is completed within 24 hr after explantation (and perhaps as soon as 4–8 hr). Those nuclei which survive (usually one per fiber) are found to be contained within separate bipolar cells closely applied to the fiber. An examination of the fine structure of these surviving cells shows them to be separate, mononucleated cells contained within the basement lamina of the degenerating fiber. These cells are identical, on the basis of their ultrastructure as well as their location, to satellite cells associated with muscle fibers in the source tissue.
Folded multiple-capture: an architecture for high dynamic range disturbance-tolerant focal plane array

Earlier studies have shown that multiple capture can achieve high SNR, but cannot satisfy the high dynamic range (HDR) and high speed requirements of the Vertically-Integrated-Sensor-Array (VISA) project. Synchronous self-reset, on the other hand, can achieve these requirements, but suffers from poor SNR. Extended counting can achieve high dynamic range at high frame rate and with good SNR, but at the expense of high power consumption. The paper proposes a new HDR focal plane array architecture, denoted by folded-multiple capture (FMC), which by combining features of the synchronous self-reset and multiple capture schemes, can satisfy the VISA requirements at a fraction of the power dissipation and with more robustness to device variations than extended counting. The architecture is also capable of detecting subframe disturbances, e.g., due to laser jamming, and correcting for it.
Surgical Management of Iatrogenic Facial Nerve Injuries

Surgical management of an iatrogenic facial nerve injury represents a significant challenge for the otologic surgeon. The decision to perform facial nerve grafting is a difficult one and is based on the extent of injury to the nerve. We conducted a review of 22 patients who had sustained iatrogenic facial nerve injuries during otologic surgery that required surgical exploration. The facial nerve was transected more than half its diameter in 13 of the patients. All of these patients' nerves were repaired either with direct reanastomosis of the facial nerve or with a cable nerve graft. The transection was less than 50% in nine of the patients in the study group. Eight of these patients underwent only decompression of the facial nerve. No patient with a neural repair (direct anastomosis or cable graft) had better than a House grade III result. All of the patients undergoing direct anastomosis of the nerve obtained a House grade III result. The most common result in patients undergoing cable nerve grafting was a House grade IV. The only patients with normal or near-normal facial nerve function (House grade I or II) had only decompression of the facial nerve. Five of the eight patients undergoing decompression had results similar to those undergoing cable nerve grafts. We conclude that acceptable results can be obtained when the facial nerve is repaired by direct anastomosis or a cable nerve graft. These results are comparable with those of patients treated with decompression only. When in doubt as to the extent of injury, it is preferable to repair the facial nerve, because the extent of injury may be underestimated.
Concurrent validity of the PPVT‐R for “at risk” preschool children

The PPVT-R and McCarthy Scales of Children's Abilities were compared in a counterbalanced design for 35 preschool children identified previously as being “at risk.” Nonsignificant differences were found between Forms L and M of the PPVT-R and the McCarthy GCI. Correlations between the PPVT-R and the McCarthy GCI and Scale scores all were significant and in the moderate range of .41 to .69. Alternate form reliability of the PPVT-R was .87.
Crime change patterns in American cities

Abstract A longitudinal analysis of the changes in crime rates between the late 1950s and 1970 in the 155 largest U.S. cities indicates that (1) there is virtually no relationship between the four major crimes against persons although there is strong mutual association between the four major crimes against property; (2) changes in racial composition account for more variation in changes in crime than do changes in income, thereby suggesting the need for more detailed studies of the noneconomic ways in which a city's racial composition affects crime incidence; and (3) there is a modest relationship between changes in the number of male youth and changes in certain types of crime. Since these findings are based on highly aggregated data with both known and unknown measurement errors, they must be treated cautiously.
Synonymous SNPs Provide Evidence for Selective Constraint on Human Exonic Splicing Enhancers

The human SNP database was used to detect selection on 238 hexamers previously identified as exonic splicing enhancers (ESEs). We compared the distribution of the 238 putative ESEs in biallelic and triallelic SNPs within five different functional categories of the SNP database: synonymous, nonsynonymous, introns, UTRs, and nongenic SNPs. Since true ESEs do not function outside of exons, SNPs that disrupt ESE motifs were expected to be more common in nonexonic portions of the genome. Our results supported this expectation: ESEs were least prevalent within synonymous SNPs and most common in nongenic SNPs. There were approximately 11% fewer ESEs within synonymous biallelic SNPs than expected under no selective constraint. We also compared the frequency of neutral SNPs, those where neither allele was an ESE, with deleterious SNPs, those where one or more alleles was an ESE, across the five different functional classes of SNPs. In comparison with the other functional classes of SNPs, synonymous SNPs contained an excess of neutral variants (+1.64% and +6.04% for biallelic and triallelic SNPs, respectively) and a dearth of deleterious variants (-13.11% and -52.39% for biallelic and triallelic SNPs, respectively). The observed patterns were consistent with purifying selection on the 238 hexamers to maintain their function as ESEs. However, in contrast to previous work, we did not find evidence for selection to maintain ESE function at nonsynonymous SNPs because selection at the protein level probably obscured any difference at the level of ESE function.
Performance analysis of the adaptive line enhancer with multiple sinusoids in noisy environment

In this paper, the performance analysis of the adaptive line enhancer when the input signal consists of multiple sinusoids embedded in noise is investigated. The performance is evaluated in terms of the signal-to-noise ratio gain at the filter's output. It is shown that, for multiple sinusoids, this gain is not only a function of the filter length, but also of three additional factors -- the number of sinusoids, the noise power, and the amplitude of each sinusoid. Simulation results for a dual noisy sinusoidal input are presented to illustrate the validity of this analysis.
Clothing as a symbol of status: Its effect on control of interaction territory

Based upon status ratings by 154 adults, three types of attire (clothing typical of a student, a priest, and a businessman) were selected for use in a field study investigating control of interaction territory. Two male confederates, one neatly but casually dessed, the other dressed as a student, priest, or businessman, were situated in a department store doorway either 42 or 54 in. apart. During half of the 600 observations, the confederates were conversing. At the close distance, people tended to detour around all dyads; neither attire nor conversation affected the number of territorial invasions. At the far distance, shoppers frequently invaded the space between the nonconversing confederates; when conversing, however, dyads with a member dressed as a priest or businessman (higher status ratings) detoured significantly more shoppers than the dyad with a member dressed as a student (lower status rating). The results indicate that cues to the status of one’s social role provided by attire are important determinants of the sanctity of one’s interaction territory.
Evaluation of the Spectral Phonocardiographic Analysis

Heart sounds can be divided into three classes: short duration pulses (first and second heart sounds); broadband long duration noise (murmur); and long duration sounds having distinct harmonic pattern (musical murmurs). The characteristics of the analysis of these classes are illustrated, and the timing, duration, and filtering artifacts are discussed. A comparison between phase and amplitude filtering is given. Application of this research instrument to clinical size and cost is considered.
Motivation and learning in mice after goldthioglucose-induced hypothalamic lesions

Shock-avoidance training was given to normal mice and to mice with goldthioglucose-induced lesions in the ventromedial region of the hypothalamus. The lesioned mice learned faster than the control mice. Lesions in the ventromedial region of the hypothalamus may alter the emotionality of an animal and thus its motivation during learning.
Stress, behavioral arousal, and open field activity--A reexamination of emotionality in the rat

The effects of stress upon emotionality, and of emotionality upon the open field activity of rats have now been studied for over four decades. Controversy remains however regarding the degree to which stress alters behavior, and the direction of that change. One reason for this is the absence of an adequate behavioral definition of stress. The present series of experiments demonstrates a standard relatively nontraumatic stress induction procedure which may be used in conjunction with open field testing. Pre-exposure to moderately intense light and white noise facilitated open field activity as measured by initial activity, lowered defecation scores, and supplementary measures (rearing, grooming, center field penetration). Further parametric, psychoendocrine, and pharmacological studies characterized the nature of the facilitation, its time course, and its modification by other manipulations. Our results suggest the initial behavioral response to stress in an open field is activation. Previous studies may have differed in their results relating stress and behavior because of subtle procedural distinctions, some of which may be identified using the present technique.
EFFECT OF DEAFFERENTATION UPON ACQUISITION OF A CONDITIONED FLEXION RESPONSE IN THE CAT.

Abstract The ability of naive cats to acquire a conditioned flexion response in a hind limb deprived of sensory inflow was studied. In some cats dorsal-root section was extended from T13 through S3, while in others a more restricted deafferentation was carried out. A bipolar stimulating electrode was chronically implanted on dorsal root L6. The cats were subjected to a classical conditioning procedure in which tone (CS) was paired with shock (US) delivered through the dorsal-root electrode. All animals were given at least 750 training trials over 19 training sessions. The US produced a consistent flexion of the deafferented leg, and EMG recordings showed that the deafferented flexor muscles contracted to the US. None of four cats with complete deafferentation of the muscles participating in the unconditioned responses acquired a conditioned flexion response in the deafferented limb. Four other cats with partial deafferentation of the hind limb all developed conditioned flexion responses in that limb. We conclude that, in the cat, a classically conditioned flexion response cannot be acquired in the hind limb without local sensory inflow.
Advancing economic analysis beyond the equilibrium framework

Twentieth century economics was dominated by the development and refinement of the concept of economic equilibrium. While it is worthwhile to understand the properties of economic equilibrium, equilibrium concepts have dominated economic thought to the point that they have obscured some of the more important issues economists have always strived to understand. At least since Adam Smith’s time, economists have tried to understand the causes of prosperity, and how economic welfare can be enhanced, but these issues are best understood outside the equilibrium framework. The foundations provided by the Austrian school point toward ways that economic analysis can expand beyond the equilibrium framework.
The influence of financial status on the effectiveness of environmental enforcement

Abstract This paper analyzes the influence of financial status on the effectiveness of environmental enforcement. It considers multiple dimensions of both enforcement and financial status. Regarding enforcement, the paper considers both the likelihood of enforcement, as captured by the likelihood of inspections conducted at regulated facilities, and the severity of enforcement, as captured by the size of sanctions imposed on polluting facilities found violating their effluent limits. As indicators of corporate financial status, the paper considers measures of liquidity, solvency, and profitability [a proxy for corporate managerial skill], all of which can influence the likelihood that a firm faces liquidity and/or bankruptcy constraints. The paper first develops a theoretical model of optimal abatement in the presence of liquidity and bankruptcy constraints and uses the model to investigate the impact of financial status on optimal abatement and the effectiveness of enforcement. Then the paper empirically examines the interactions between enforcement and financial status using data on wastewater discharges from US chemical manufacturing facilities for the years 1995 to 2001. Empirical results suggest that the financial status dimensions considered here in general play an important role in determining the incentives created by enforcement. As the most striking result, we show theoretically and empirically that, when financial dimensions are included in the analysis, the conventional wisdom regarding the effect of enforcement likelihood on abatement no longer holds, i.e., increased enforcement can actually lead to worse environmental performance.
Uranium and boron distributions in some oceanic ultramafic rocks

From mica fission-track maps the serpentinized and weathered portions of four ultramafic rocks from oceanic ridge systems contained 0.5 to 2.4 ppM U compared to only 2.5 ppB in clinopyroxene, 0.6 ppB in chromite and < 7.0 ppB in olivine. Orthopyroxene grains contained 0.4 ppB U which is three orders of magnitude lower than had previously been reported. Long thin tracks from (n, alpha ) reactions with boron were recorded in cellulose nitrate plastic and were counted like fission tracks. The track density from boron was 2 x 10/sup 4/ times higher than that from uranium fission alone. Boron in serpentine was variable on a 50- mu m scale attaining 155 ppM concentrations. Orthopyroxene grains, in contrast, had maximum concentrations of 0.8 ppM. Most of the uranium and boron in the rocks is believed to have been introduced during serpentinization. From known crystal-melt partitioning ratios the uranium and boron distributions are consistent with the ultramafic rocks being cumulates or residues from partial melting events. (auth)
MMPI-2 SCHIZOPHRENIA SPECTRUM PROFILES AMONG SCHIZOTYPAL COLLEGE STUDENTS AND COLLEGE STUDENTS WHO SEEK PSYCHOLOGICAL TREATMENT'

The MMPI-2 schizophrenia spectrum profiles of 25 college students with extreme scores on the Perceptual Aberration and Magical Ideation Scales were compared to those of 27 students who requested ps...
Graph-based robust resource allocation for cognitive radio networks

In this paper, we investigate robust resource allocation for cognitive radio networks. First, a resource allocation scheme based on stable matching is developed, which takes the preferences of both secondary users and primary users into account. To improve its robustness, we then discuss an ϵ-stable resource allocation scheme. With the help of the properties of ϵ-stable resource allocation, three edge-cutting algorithms are proposed. Numerical results show that the modified algorithms are robust to the channel state information variation.
Infected Cells Call Their Killers to the Scene of the Crime

Effector CD8 + T cells scan tissues to locate and kill infected host cells. In this issue of Immunity , Hickman et al. (2015) show that the exploration is not random: infected monocytes attract their assassins by secreting chemokines, which accelerates clearance of epicutaneous vaccinia virus infection.
Charges on jet drops produced by bursting bubbles

Abstract The sizes and charges of jet drops produced by bursting air bubbles are examined experimentally. The variation in charge for bubble lifetimes of up to 200 sec in NaCl and KCl solutions is reported. Jet drops refer to drops produced by a jet rising from a cavity left in a liquid surface by a bursting bubble; bubble lifetime is the interval during which a bubble is in motion between generation and rupture. With other variables held constant, drop charge shows a characteristic variation of a rise to a maximum followed by a decrease to an asymptotic value, as bubble lifetime is increased. The influences of various parameters on the characteristic behavior are discussed.
Receptor for Advanced Glycation End Products (RAGE) and Implications for the Pathophysiology of Heart Failure

The receptor for advanced glycation end products (RAGE) is expressed in the heart in cardiomyocytes, vascular cells, fibroblasts, and in infiltrating inflammatory cells. Experiments in murine, rat, and swine models of injury suggest that RAGE and the ligands of RAGE are upregulated in key injuries to the heart, including ischemia/reperfusion injury, diabetes, and inflammation. Pharmacological antagonism of RAGE or genetic deletion of the receptor in mice is strikingly protective in models of these stresses. Data emerging from human studies suggest that measurement of levels of RAGE ligands or soluble RAGEs in plasma or serum may correlate with the degree of heart failure. Taken together, the ligand-RAGE axis is implicated in heart failure and we predict that therapeutic antagonism of RAGE might be a unique target for therapeutic intervention in this disorder.
Beryllium-10 in australasian tektites: evidence for a sedimentary precursor.

Each of seven Australasian tektites contains about 100 micron atoms of beryllium-10 (half-life, 1.53 million years) per gram. Cosmic-ray bombardment of the australites cannot have produced the measured amounts of beryllium-10 either at the earth's surface or in space. The beryllium-10 contents of these australites are consistent with a sedimentary precursor that adsorbed from precipitation beryllium-10 produced in the atmosphere. The sediments must have spent several thousand years at the earth's surface within a few million years of the tektite-producing event.
A study of the dynamics of retrograde transport and accumulation of horseradish peroxidase in injured neurons

Abstract The phenomenon of retrograde intraaxonal transport of extracellular markers introduced at the level of the axon terminal has been suggested as a possible mechanism of communication between the axon terminal and the neuron cell body. We tested the hypothesis that communication after axotomy might consist of a change in the rate of uptake or of transport of material by injured neurons. Small lesions were made with a needle in one retinal quadrant of chicks and immediately afterwards horseradish peroxidase (HRP) was injected into the vitreous body of the eye. The amount of HRP accumulated by some of the neurons of the isthmo-optic nucleus (ION) which project to the damaged areas was clearly different from that of nearby cells which project to the non-damaged portions of the retina. The uninjured cells accumulated enzyme marker beginning at 3.5 h after injection. The injured neurons did not accumulate significant amounts of HRP until between 4 and 6 h after injection. Between 6.75 h and 18 h the injured cells in the ION accumulated greater amounts of HRP than cells in other regions, but by 24 h the cells of the ION in the region of injury contained distinctly less label. This pattern of enzyme accumulation was confirmed by counts of the number of HRP-positive granules within cells of chicks fixed 4, 11.75, 12.25, 27.6 and 72 h after injury. In another series of experiments, the axon terminals of the ION were first exposed to HRP, and 1 h later some of the axons were damaged with a needle. In these cases, there was no difference between the injured and control neurons in the time of first appearance of labeled cells in the ION within the first 4 h after injection of HRP. These findings suggest that injury initially results in a decrease in the uptake of the marker rather than a decrease in the rate of retrograde transport. The amount of marker found in the injured neurons later is greater than that found in the control neurons. This subsequent difference may represent an increase in the rate of uptake, transport, or both or a decrease in the rate of degradation of HRP within the cell body as a response to injury of the axon.
Singular Vectors and Time-Dependent Normal Modes of a Baroclinic Wave-Mean Oscillation

Abstract Linear disturbance growth is studied in a quasigeostrophic baroclinic channel model with several thousand degrees of freedom. Disturbances to an unstable, nonlinear wave-mean oscillation are analyzed, allowing the comparison of singular vectors and time-dependent normal modes (Floquet vectors). Singular vectors characterize the transient growth of linear disturbances in a specified inner product over a specified time interval and, as such, they complement and are related to Lyapunov vectors, which characterize the asymptotic growth of linear disturbances. The relationship between singular vectors and Floquet vectors (the analog of Lyapunov vectors for time-periodic systems) is analyzed in the context of a nonlinear baroclinic wave-mean oscillation. It is found that the singular vectors divide into two dynamical classes that are related to those of the Floquet vectors. Singular vectors in the “wave dynamical” class are found to asymptotically approach constant linear combinations of Floquet vector...
Ciprofloxacin Causes Persister Formation by Inducing the TisB toxin in Escherichia coli

Bacteria induce stress responses that protect the cell from lethal factors such as DNA-damaging agents. Bacterial populations also form persisters, dormant cells that are highly tolerant to antibiotics and play an important role in recalcitrance of biofilm infections. Stress response and dormancy appear to represent alternative strategies of cell survival. The mechanism of persister formation is unknown, but isolated persisters show increased levels of toxin/antitoxin (TA) transcripts. We have found previously that one or more components of the SOS response induce persister formation after exposure to a DNA-damaging antibiotic. The SOS response induces several TA genes in Escherichia coli. Here, we show that a knockout of a particular SOS-TA locus, tisAB/istR, had a sharply decreased level of persisters tolerant to ciprofloxacin, an antibiotic that causes DNA damage. Step-wise administration of ciprofloxacin induced persister formation in a tisAB-dependent manner, and cells producing TisB toxin were tolerant to multiple antibiotics. TisB is a membrane peptide that was shown to decrease proton motive force and ATP levels, consistent with its role in forming dormant cells. These results suggest that a DNA damage–induced toxin controls production of multidrug tolerant cells and thus provide a model of persister formation.
Magnetization of dilute Ag-Mn alloys: Ordering and absence of Kondo state☆

Abstract The magnetization of Ag-Mn alloys containing 100 ppm-4 ppm of Mn has been measured from 0.5 K down to 10 mK. For the high concentrations, ordering sets in at a temperature proportional to impurity concentration; there is no evidence for a spin-compensated Kondo state.
Leg Pain in a Patient with Myasthenia Gravis

A 79-year-old male with myasthenia gravis on chronic prednisone therapy presented with progressive left leg pain and swelling and nonproductive cough for one month. Physical examination was significant for multiple, irregular, tender areas of induration in his bilateral lower extremities without overlying erythema. Laboratory data were significant for a white cell count of 12,400/cmm. MRI showed multifocal abscesses in his bilateral lower extremities within the muscle beds, which were more significant on the left (Fig. 1). He underwent ultrasound-guided drainage of the large abscesses. Cultures grew Nocardia pseudobrasiliensis sensitive to moxifloxacin. CT chest showed bilateral pleural effusions and ground-glass opacities in the right upper lobe, suggesting pulmonary nocardiosis with dissemination secondary to immunosuppression from chronic steroid use. The patient was started on moxifloxacin with a plan to treat for 12 months. Figure 1. MRI of the left leg demonstrating multifocal abscesses in multiple muscular beds. The majority of patients with nocardial infection are immunocompromised; the most common causes are glucocorticoid therapy, malignancy, organ transplantation, and HIV infection. Disseminated nocardial infection typically presents with deep abscess especially in the lower extremities or CNS.1 Treatment requires a long course of therapy: 6 months for pulmonary or systemic nocardiosis and at least 12 months for immunocompromised patients.2 Suspect norcardiosis in patients with CNS, soft tissue, or cutaneous lesions and a concurrent pulmonary process.
Preoperative vancomycin prophylaxis decreases incidence of postoperative hemodialysis vascular access infections

The role of vancomycin in the treatment of infected arteriovenous chronic dialysis access is well established. However, the role of preoperative vancomycin administration in preventing infection in newly placed, revised, or surgically thrombectomized grafts has not been determined. We performed a prospective randomized study to examine whether vancomycin prophylaxis can decrease the incidence of postoperative graft infections. Over a 5-year period, 206 patients undergoing 408 permanent vascular access procedures were randomized into two groups. Group 1 (206 procedures) received a single intravenous dose of 750 mg of vancomycin approximately 6 to 12 hours before vascular access placement procedures, while group 2 (202 procedures) did not. Patients were evaluated for access infection within the following 30 days and before use of the access for chronic dialysis. Access infection developed in two patients (1%) in group 1 and in 12 patients (6%) in group 2 (P = 0.006). All 14 infections occurred in upper extremity polytetrafluoroethylene grafts. We conclude that the use of preoperative single-dose intravenous vancomycin prophylaxis for hemodialysis vascular graft procedures reduces the risk of postoperative access infection.
Activity-dependent remodeling of connections in the mammalian visual system

The development of precise connections in the mammalian central nervous system requires neural activity. Synchronous patterns of afferent activity, and coincident afferent and target activity are required for specifying the neuronal connectivity that characterizes the adult visual pathway in mammals. During development, postsynaptic target neurons communicate with presynaptic afferents. Recent evidence suggests that the mechanisms that underlie activity-dependent development of connections in the visual system may share significant similarities with the mechanisms responsible for synaptic plasticity in the adult brain.
Estimation of creep strain due to intergranular cavitation

La vitesse de deformation par cavitation parallele a la contrainte uniaxiale peut etre estimee en controlant la fraction volumique des cavites en fonction du temps grâce a des essais de fluage interrompus. La vitesse de deformation par cavitation est hautement anisotrope et son amplitude parallelement a l'axe des contraintes peut etre une fraction significative de la vitesse de deformation par fluage a l'etat stationnaire
Mass transport and kinetic limitations in MOCVD selective-area growth

Abstract The interplay between transport and kinetics in selective-area growth (SAG) of compound semiconductors is discussed. A thin-film model describing transport of reactants across the boundary layer above the growth surface is developed. A dimensionless Damkohler number ( Da ) quantitatively determines whether the planar (blanket) deposition is in a transport-limited, reaction-rate-limited, or intermediate operating regime. Reactant profiles within the rotating-disk reactor and growth rates predicted by the thin-film model agree very well with numerically exact calculations. The efficiency of the SAG was found to be a strong function of both the Da and the pattern fill-factor ( θ ). The thin-film model was extended to take into account the lowering of the “effective rate constant” (averaged over both the exposed and masked zones). It was found that the product θDa governs the transition between transport and kinetic control of the SAG process. Predictions of the analytical SAG thin-film model were compared to both the numerically exact 2-D calculations and to experimental results from InGaAs, InP, and GaN SAG. The simple theory appears to provide an excellent qualitative and quantitative description of kinetic and transport effects in SAG.
Age and Sequencing Norms in the Transition to Adulthood

The timing and sequencing of events marking the transition to adulthood have become the focus of a growing body of research. Recently, the concept of social norm has been used to provide an explanation for observed regularity in the process of transition to adulthood, and the degree of conformity to social norms governing the transition has been hypothesized to have consequences for individuals in adulthood. In this paper it is argued that the concept of social norm has limited usefulness as an explanation of behavior marking the transition to adulthood or as an explanation of its consequences. It is argued further that previous use of the concept in empirical research has been misleading because the research has not measured social norms. Over the past few years, sociologists have paid increasing attention to the study of age differentiation and the social organization of the life course. Much theorizing in this area assumes a normative model of the life course, whereby norms, or shared expectations, regarding an appropriate timetable for major life events frame the life course. These norms are assumed to be supported by informal sanctions, resulting when major deviations from the prescriptive timetable occur-for example, when a role transition occurs too early or too late (Elder, a, b; Neugarten and Datan; Neugarten et al; Riley et al.). This normative model of development over the life course has been in evidence in recent research on the transition to adulthood. Since the transition to adulthood is marked by a series of interrelated events representing movement from economic dependence and participation in the
Theory of Hydrogen Deuteride in Magnetic Fields

The Hamiltonian for the diatomic $^{1}\ensuremath{\Sigma}$ heteronuclear molecule HD in a magnetic field is discussed. Included in the Hamiltonian are the effects of the nuclear and rotational magnetic moments interacting with the external magnetic field, magnetic shielding, molecular diamagnetism, and spin-spin magnetic interaction of the two nuclei, the interaction of the nuclear magnetic moments with the field due to the rotation of the molecule, the interaction of nuclear electric quadrupole moment, and the electron coupled nuclear spin-spin interaction. General expressions for the matrix elements of such a Hamiltonian are developed. Perturbation theory expressions for the energy of HD in the first rotational state are obtained in both strong and weak-field limits. General expressions are given up to third order and numerical perturbation coefficients as calculated with a digital computing machine are given up to ninth order. The secular equation for HD is numerically solved for intermediate fields. Curves are given showing the theoretical dependence of the energy upon the field. Effects of zero-point molecular vibration and centrifugal stretching are discussed.
Net transport of glucose from blood to cerebrospinal fluid in the cat.

Abstract The net transport of glucose from blood to the cerebrospinal fluid compartment of cats was measured by ventriculocisternal perfusion to determine over a large range of serum glucose concentrations the influence of serum glucose levels and their changes on the net transport rate. Changes in serum glucose levels were followed within minutes by corresponding changes in cerebroventricular effluent fluid glucose concentration. At mean values of serum glucose concentration of 6.2 mM and cerebrospinal fluid formation rate of 24.3 μl/min, the net glucose influx rate was 1.6 mmol/min. The effluent fluid-to-serum glucose concentration ratio was 0.25 and decreased when serum glucose was greater than 11.1 mM. The rate of glucose transport from blood to effluent fluid during ventricular perfusion was saturable, and approached a maximum of 3.5 μmol/min at serum glucose levels above 22 mM. From the cererospinal fluid formation and net glucose influx rates the calculated glucose concentration of nascent cererospinal fluid was 6.5 mM and higher than the corresponding serum glucose of 5.6 mM. It is concluded that during perfusion over a wide range of serum glucose concentrations, a saturable mediated glucose transport mechanism can be demonstrated. Changes in serum glucose are rapidly reflected in corresponding effluent fluid glucose levels. From effluent fluid-to-serum glucose concentration ratios and calculations of the glucose in newly formed cerobrospinal fluid, the technique, however, overestimates the glucose influx rates at normal serum glucose levels.
Ejector in R410A vapor compression systems with experimental quantification of two major mechanisms of performance improvement: Work recovery and liquid feeding

This paper presents experimental data and analysis comparing the performance of an R410A ejector vapor compression system to those of a liquid-fed evaporator system and a conventional expansion valve system. The objective was to quantify separately two major improvements of the ejector system: work recovery and liquid-fed evaporator. The ejector system was first compared to a system with liquid-fed evaporator at matching cooling capacities and revealed improvements from 1.9% to 8.4% solely due to the work recovery of the ejector. When compared to a conventional expansion valve system at the same cooling capacity, the ejector setup improved COP from 8.2% to 14.8% due to simultaneous benefits of liquid-fed evaporator and work recovery. Overall ejector efficiencies from 12.2% to 19.2% were achieved.
REACTIONS OF PROTIC REAGENTS WITH A TUNGSTEN PHOSPHENIUM ION COMPLEX

Abstract The reactions of metallophosphenium ion complex CpW(CO)2{P(Ph)[N(SiMe3)2]} with protic reagents HBF4, HCl, and CF3COOH have been studied. The 1:1 reactions result in protonation of the WP bond, while the 1:2 reactions display cleavage of the P–N bond. The molecular structure of one product, Cp(CO)2(Cl)WP(H)(Ph)[N(SiMe3)2], was determined by single crystal X-ray diffraction techniques: triclinic space group P1 with a=9.6732(14) A, b=11.3419(15) A, c=11.5930(14) A, α=87.724(11)°, β=77.647(11)°, γ=82.989(11)°, V=1233.0(3) A3, Z=2.
Comparison of Contract General Conditions between United States and China

In light of the fact that construction projects are expensive, complex, and time-consuming undertakings, a well-written contract that specifies each participant’s duties and obligations is required. Furthermore, a well-written contract with regard to business practice differences between the United States and China is unquestionably needed by American owners, design firms, and construction companies conducting business in China. In response to this industry need, general conditions of construction contracts commonly used in the United States (AIA-A201) and China (GF-1999-0201) have been analyzed and compared. The findings of this research reveal that the content of subclauses in AIA-A201 and GF-1999-0201 is different in several ways. These differences may have been caused by cultural, historical, geographical, political, and language variations that exist between the American and Chinese construction markets. Understanding these differences could help U.S. companies stay competitive and profitable in China.
The institutional subordination of contested issues: The case of Pittsburgh's steelworkers and ministers

This essay responds to critical theory's challenge for rhetorical criticism to focus on the ways in which the exercise of power influences rhetorical practices in the public sphere. It explores how the relegation of union worker's interests to private institutional entities can result in the institutional subordination of those interests and how this subordination significantly diminishes the range of public discourse and contested issues. It analyzes a case where a group of local steelworkers in the Pittsburgh area, working in conjunction with a small group of Protestant ministers, sought to gain public support for the redress of grievances and how their subordination by the United Steel Workers' union and the Lutheran Church influenced their rhetorical activities.
Obstetric clavicular fracture: The enigma of normal birth

Objective To determine the main risk factors involved in neonatal clavicular fracture, the most common injury to the neonate. Methods Two hundred fifteen cases of clavicular fracture of 65,091 vaginal deliveries (0.4%) occurring between January 1983 and December 1988 were pair-matched with controls based on mode and date of delivery, race, and maternal age. Incidences, odds ratios, and stratified analysis were used to identify and control for confounding between risk factors. Results Shoulder dystocia, increasing birth weight, and increasing gestational age were identified as risk factors. Within the range of normal birth weights, there is a biologic gradient of increasing risk for clavicular fracture. Although shoulder dystocia is the strongest risk factor identified, the magnitude of its point estimate is probably affected to a large extent by differential ascertainment. The use of forceps, prolonged second stage of labor, and nulliparity status were not significantly associated with neonatal clavicular fracture. Conclusion Neonatal clavicular fracture occurs commonly in an obstetric population. Obstetric clavicular fracture is an unpredictable, unavoidable complication of normal birth.