cssi/SciSciGPT-SciSciNet huggingface dataset:
Abstract 12246: Is Mitochondrial DNA Fragmentation a Major Contributor to Necrosis in Myocardial Infarction?

A fusion protein based on endonuclease III, a DNA repair enzyme with pyrimidine glycosylase/AP lyase activity, engineered to enter cells and be taken up by mitochondria (EndoIII) given to ischemic mouse hearts at reperfusion reportedly reduces infarct size (IS). We tested whether EndoIII protects ischemic myocardium by preventing mitochondrial DNA (mtDNA) fragmentation. Extracellular mtDNA can be mistaken for bacterial DNA by neighboring cells and trigger an injurious inflammatory response which in the heart could lead to spreading necrosis. In situ rat hearts were subjected to 30-min coronary occlusion/2-h reperfusion. Intravenous EndoIII just prior to reperfusion reduced IS from 43.8±1.4% of risk zone in control hearts to 24.0±1.3% with no detectable hemodynamic effect. Enzymatically inactive EndoIII offered no protection. EndoIII’s protection was comparable to that of the platelet P2Y12 antagonist cangrelor (25.0±1.8% of risk zone). Because loading with a P2Y12 receptor blocker to inhibit platelets is currently standard of care for treatment of myocardial infarction (MI), we tested whether EndoIII could further reduce IS in rats treated with a maximally protective dose of cangrelor. The combination reduced IS to 15.1±0.9%, significantly smaller than that seen with either cangrelor or EndoIII alone. Protection from cangrelor but not EndoIII was abrogated by blockade of phosphatidylinositol-3 kinase or adenosine receptors indicating differing cellular mechanisms. If released mtDNA fragments induce spreading necrosis in the reperfused tissue, then degrading extracellular mtDNA with deoxyribonuclease I (DNase I) should prevent it. Intravenous DNase I at reperfusion mimicked EndoIII’s protection supporting the hypothesis. DNase I protection was additive to that of cangrelor and it also protected Krebs-perfused hearts indicating blood cells were not involved in its protection. Combining EndoIII and DNase I provided even greater protection presumably by protecting many of the ischemic cardiomyocytes and also by preventing necrosis spreading from those cells that EndoIII could not save. Because protection from EndoIII and DNase I can add to protection from a P2Y12 blocker, it should be effective in today’s patients with acute MI.
Estimation of Injury Simulation in International Women's Football

This study attempted to determine the frequency of apparent injury incidents in women's international football and estimate what proportion was authentic. Broadcast recordings of 47 games from 2 tournaments were reviewed to identify incidents in which a player behaved as if injured. Apparent injuries were considered definite if a player withdrew from participation within 5 minutes or if bleeding was visible. Remaining incidents were considered questionable. A total of 270 apparent injuries were observed at a rate of 5.74/game compared with 11.26/game previously reported in men's football. The definite injury rate was only 0.78/game vs. 4.96/game for questionable injuries. Definite injuries were associated with on-field treatment (P < 0.010), stretcher (P < 0.010), and second half (P = 0.022), while questionable injuries were associated with fouls (P = 0.036), contact (P < 0.010), and being tackled (P = 0.025). Questionable injuries were not associated with the final third of a half or with team success.
Time From Pregnancy Recognition to Prenatal Care and Associated Newborn Outcomes

ABSTRACT Objective To examine the relationship between newborn outcomes and late prenatal care initiation after recognition of pregnancy. Design Secondary data analysis of the Pregnancy Risk Assessment and Monitoring System (PRAMS) data for the United States. Setting Twenty‐nine states. Participants Women of childbearing age (135,623) who resided in 29 states in the PRAMS study who received prenatal care and had live births. Methods Population‐based survey from 2000 through 2004 that examined four newborn outcomes: prematurity, low birth weight (LBW), admission into Neonatal Intensive Care Unit (NICU), and infant mortality. Results The average time lag (difference between the time of pregnancy recognition and initiation of prenatal care) for the study was 3.2 weeks (99% CI [3.12, 3.21]). Women who recognized their pregnancies before 6 weeks had a longer lag time (3.5 weeks, 99% CI [3.43, 3.53]) than women who recognized their pregnancies later (2.1 weeks, 99% CI [1.96, 2.15]). After adjusting for confounders including the timing of pregnancy recognition, longer time lag was associated with reduced risks of prematurity (odds ratio [OR]=0.99, 99% Confidence Interval [CI] [0.97, 1.00], p p p p >.01). Conclusion Average time lag from pregnancy recognition to prenatal care was not associated with poor newborn outcomes once results were adjusted for time of pregnancy recognition and other confounders.
Effect of Uridine on de Novo Pyrimidine Biosynthesis in Rat Hepatoma Cells in Culture

Abstract Some of the factors responsible for the control of pyrimidine nucleotide biosynthesis in intact cells have been investigated using rat hepatoma cells grown in continuous culture. The addition of uridine (0.5 mm) to culture medium causes a decrease of approximately 70% in the rate of de novo pyrimidine nucleotide biosynthesis, as determined by incorporation of 14CO2. Maximum inhibition of 14CO2 incorporation into pyrimidine nucleotides occurs within 60 min of addition of the uridine. After the uridine has been removed, the rate of 14CO2 incorporation recovers to normal levels with 8 hours. This recovery can be prevented by the addition of actinomycin D or cycloheximide to the medium. Uridine causes a decrease of approximately 70% in the level of activity of orotate phosphoribosyltransferase; it does not significantly affect the activity of carbamyl-P synthetase, aspartate transcarbamylase, dihydroorotase, orotidine decarboxylase, or uridine kinase when these enzyme activities are measured in cell extracts. The decreased level of activity of orotate phosphoribosyltransferase is not due to a direct effect of uridine on the enzyme. The inhibition can be reversed by removal of uridine from the culture medium, but only if transcription and translation are not interfered with by the addition of actinomycin D or cycloheximide. Measurement of enzymes of the de novo pyrimidine biosynthetic pathway (except for dihydroorotate dehydrogenase) under optimal conditions suggests that orotate phosphoribosyltransferase is rate-limiting in the biosynthesis of uridylic acid. The parallel effects of addition and removal of uridine on 14CO2 incorporation into pyrimidine nucleotides and on orotate phospho-ribosyltransferase activity support this suggestion.
How to Love a Woman with No Legs

Commit to it, like you have something to prove, like you can make up for what's gone, like nothing at all is gone. Like she's all there and yours for the taking. It'll be easy. If it's not easy, well, you have nothing to lose. Laugh. Of course you don't?she's already lost enough for both of you. Feel guilty for that loss while you're still a kid. Slip that loss into your pocket to use when you get older, to pull out at parties when people's minds are slow and sad with wine?let them feel guilty. It'll be the best party-trick you know, but that'll happen later. Until then, there are no parties. There is only her. Eventually, the remainder of her will disappear, and this should not be lost on you, not even when you are ten years old. Rage against her impending departure. Love her fiercely, more than a child should ever know how to love a grandmother. Think of love as a fistfight. Fight for her like cowboys and Indians, like war, like something you'll lose sooner or later but play anyway because if you don't play you'll be alone. Pretend you've been given the choice, rather than the white doc tors at the Indian hospital. Consider what is left of her body. Which piece will you pick to disappear next? Not those giant hands, soft as well-oiled catchers' mitts. Not her long silver braid of hair?she lets you touch it and brush it with your fingers. Don't think about her nipples, hanging like overripe figs, dark ovals at the bottom curves of her flabby breasts?dark enough to look like two stains beneath her translucent nightgown. Look away. It's not nice to stare at them, your mother says. If you absolutely have to pick something about her to forget or to get rid of, and that something doesn't have to be a body part, choose the nightgowns. They make her look like a ghost hovering above the green tile floor of her room. Your second choice should be the bedpan, the heavy steel pan you must move from the one chair in her room when you want to sit. But that's it. Sit and listen to her stories, even if you've heard them all before. When she tells you about the Indian school, be still. It'll be your
Generation of a stable packaging cell line producing high-titer PPT-deleted integration-deficient lentiviral vectors

The risk of insertional mutagenesis inherent to all integrating exogenous expression cassettes was the impetus for the development of various integration-defective lentiviral vector (IDLV) systems. These systems were successfully employed in a plethora of preclinical applications, underscoring their clinical potential. However, current production of IDLVs by transient plasmid transfection is not optimal for large-scale production of clinical grade vectors. Here, we describe the development of the first tetracycline-inducible stable IDLV packaging cell line comprising the D64E integrase mutant and the VSV-G envelope protein. A conditional self-inactivating (cSIN) vector and a novel polypurine tract (PPT)-deleted vector were incorporated into the newly developed stable packaging cell line by transduction and stable transfection, respectively. High-titer (~10(7) infectious units (IU)/ml) cSIN vectors were routinely generated. Furthermore, screening of single-cell clones stably transfected with PPT-deleted vector DNA resulted in the identification of highly efficient producer cell lines generating IDLV titers higher than 10(8) IU/mL, which upon concentration increased to 10(10) IU/ml. IDLVs generated by stable producer lines efficiently transduce CNS tissues of rodents. Overall, the availability of high-titer IDLV lentivirus packaging cell line described here will significantly facilitate IDLV-based basic science research, as well as preclinical and clinical applications.
Surgical reconstruction of a severely comminuted mandibular fracture in a horse

Summary A Palomino gelding presented for evaluation of a mandibular fracture and physical examination revealed swelling and excoriation of the skin over the ventral mandible. Upon further examination, malalignment of the incisors was appreciated in addition to instability and crepitance of both the rostral aspect and vertical ramus of the mandible. Radiographic examination revealed a comminuted fracture within the interdental space and fractures of both vertical ramii of the mandible. Under general anaesthesia via tracheotomy intubation, the fractures of the vertical ramii were reduced and compression plating techniques used along the caudal-lateral border of both ramii for stabilisation. Intraoral tension band wires were used for repair of the interdental space fracture. A type II external skeletal fixator using Steinmann pins and polymethyl methacrylate connecting bars was applied to increase stability. The horse was maintained on broad spectrum antibiotics and phenylbutazone and discharged following 6 days of hospitalisation. Radiographs were taken 10 weeks after surgery and revealed evidence of adequate healing. On follow-up 20 months later, the horse was reported to have no difficulties eating and was maintaining its bodyweight. This case is unique due to the severity of the mandibular fracture. The authors are unaware of any previous reports of such a severely comminuted mandibular fracture and its successful reconstruction employing multiple surgical techniques.
Domain structure and functional analysis of the carboxyl-terminal polyacidic sequence of the RAD6 protein of Saccharomyces cerevisiae

The RAD6 gene of Saccharomyces cerevisiae, which is required for normal tolerance of DNA damage and for sporulation, encodes a 172-residue protein whose 23 carboxyl-terminal residues are almost all acidic. We show that this polyacidic sequence appends to RAD6 protein as a polyanionic tail and that its function in vivo does not require stoichiometry of length. RAD6 protein was purified to near homogeneity from a yeast strain carrying a RAD6 overproducing plasmid. Approximately the first 150 residues of RAD6 protein composed a structural domain that was resistant to proteinase K and had a Stokes radius typical of a globular protein of its calculated mass. The carboxyl-terminal polyacidic sequence was sensitive to proteinase K, and it endowed RAD6 protein with an aberrantly large Stokes radius that indicates an asymmetric shape. We deduce that RAD6 protein is monomeric and comprises a globular domain with a freely extending polyacidic tail. We tested the phenotypic effects of partial or complete deletion of the polyacidic sequence, demonstrating the presence of the shortened proteins in the cell by using antibody to RAD6 protein. Removal of the entire polyacidic sequence severely reduced sporulation but only slightly affected survival after UV irradiation or UV-induced mutagenesis. Strains with deletions of all but the first 4 or 15 residues of the polyacidic sequence were phenotypically almost wild type or wild type, respectively. We conclude that the intrinsic activity of RAD6 protein resides in the globular domain, that the polyacidic sequence has a stimulatory or modifying role evident primarily in sporulation, and that only a short section apparently functions as effectively as the entire polyacidic sequence.
Optimal and near-optimal techniques for multiprocessor scheduling of multiple-rate algorithms on synchronous multiprocessor systems

The authors describe two multiprocessor compiler techniques that generate synchronous multiprocessor schedules for multiple-rate algorithms represented by fully specified flow graphs (FSFGs) which contain up-samplers and down-samplers. The first scheduling technique is based on a modified multi-cyclic multiprocessor compiler that finds globally optimal solutions. The second technique generates near-optimal solutions by trading global optimality for a lower scheduling complexity. These scheduling techniques are illustrated with examples. >
Recovery of signals from nonuniform samples using iterative methods

An iterative method for recovering a bandlimited signal from its ideal nonuniform samples is proposed. The convergence of iterations is proved, and general regions for the convergence factor are found. It is shown that the iterative method is applicable to other forms of nonuniform sampling, i.e. natural sampling and interpolated sampling (such as sample and hold). >
An introduction to the NASA Shuttle ground operations simulator (SGOS)

The Shuttle ground operations simulator (SGOS) simulation software introduced in this paper is used to train NASA ground controllers and to certify launch countdown readiness. The SGOS executive and its subsystems have been an integral component of the Shuttle Launch Safety Program for almost 30 years. It is usable (via a LAN) by over 2000 NASA employees at the Kennedy Space Center and 11 000 contractors. SGOS supports over 800 models comprised of several hundred thousand lines of code and over 1000 Model Control Procedures. Copyright © 2007 John Wiley & Sons, Ltd.
Obesity: A Transgenerational Problem Linked to Nutrition during Pregnancy

The increased obstetric risks of maternal obesity have been well described. These include increased risks of gestational diabetes mellitus, preeclampsia, stillbirth, and cesarean delivery. The fetal/neonatal consequences of prenatal maternal obesity have received less attention. In addition to an increased risk of stillbirth, the fetal/neonatal consequences include increased adiposity and a metabolic status that increases the lifetime risk of obesity and diabetes. This review focuses on the clinical obstetric consequences of maternal obesity and highlights recent mechanistic insights on fetal programming as well as evidence suggesting that prenatal care provides a unique opportunity to ameliorate these risks and decrease the cycle of childhood obesity.
Donor cell survival and repopulation after intraarticular transplantation of tendon and ligament allografts.

The specific cells within ligaments and tendons are important to maintain the unique structural and material properties of these tissues. The use of tendon and ligament allografts with living cells for ligament reconstruction would be desirable assuming that these cells would survive after transplantation and continue to function. We assessed the fate of donor cells in fresh allografts of the patellar and anterior cruciate ligaments after transplantation. The cells in these allografts used to reconstruct the anterior cruciate ligament did not survive. This was demonstrated using a DNA probe technique that clearly distinguished donor cells from host cells in the Spanish goat model. The donor cells were replaced by host cells in a rapid manner. The host cells that repopulated the allografts assumed the histologic similarity to the fibroblasts they replace. Simultaneous full-thickness skin transplants in the same animals were not rejected during the interval of rapid loss of donor DNA from the allografts. The absence of rejection of the skin grafts at the one-week interval suggests that no pre-existing antibody associated with an immune reaction was responsible for the rapid loss of DNA in the allografts. The clinical basis for utilizing intra-articular allografts with living donor cells needs further justification to account for their increased expense, more complicated surgical logistics, and higher potential risk of disease transmission.
Immunohistochemical localization and radioenzymatic measurements of serotonin (5-hydroxytryptamine) in hearts of Aplysia and several bivalve mollusks

Serotonin immunoreactivity was localized in hearts of the opisthobranch gastropod, Aplysia californica (sca hare) and several species of bivalve mollusks, the heterodonts, Mercenaria mercenaria (quahog or cherry stone clam), Protothaca staminea (little neck clam), and the pteriomorphs, Hinnites multirugosus (rock scallop), Crassostrea virginica (eastern oyster), Mytilus edulis (eastern mussel), and Geukensia demissa (ribbed mussel). In addition, serotonin was assayed in the ventricles, auricles and heart-associated tissues in A. californica, M. mercenaria, H. multirugosus, and G. demissa with a sensitive radioenzymatic assay. Serotonin concentrations and the density of innervation were significantly higher in members of the subclass Heterodonta compared to the subclass Pteriomorpha. Serotonin immunoreactivity was observed in all species surveyed except G. demissa, which also contained relatively low concentrations of serotonin. Varicose fibers presumably corresponding to release sites were localized in the ventricles, auricles, and the auricular-ventricular valves. We hypothesize that in the species where serotonin-immunoreactive fibers are present, serotonin serves to modulate cardiac myogenic activity. The significance of the observed distribution and concentration of serotonin to the physiological effects of serotonin on cardiac function in these species is discussed.
Selective block minimization for faster convergence of limited memory large-scale linear models

As the size of data sets used to build classifiers steadily increases, training a linear model efficiently with limited memory becomes essential. Several techniques deal with this problem by loading blocks of data from disk one at a time, but usually take a considerable number of iterations to converge to a reasonable model. Even the best block minimization techniques [1] require many block loads since they treat all training examples uniformly. As disk I/O is expensive, reducing the amount of disk access can dramatically decrease the training time. This paper introduces a selective block minimization (SBM) algorithm, a block minimization method that makes use of selective sampling. At each step, SBM updates the model using data consisting of two parts: (1) new data loaded from disk and (2) a set of informative samples already in memory from previous steps. We prove that, by updating the linear model in the dual form, the proposed method fully utilizes the data in memory and converges to a globally optimal solution on the entire data. Experiments show that the SBM algorithm dramatically reduces the number of blocks loaded from disk and consequently obtains an accurate and stable model quickly on both binary and multi-class classification.
Brief Report: Diminishing Geographic Variability in Autism Spectrum Disorders Over Time?

We investigated differences in the geographic distribution of autism spectrum disorders (ASD) over time in central North Carolina with data from the Autism and Developmental Disabilities Monitoring Network. Using generalized additive models and geographic information systems we produced maps of ASD risk in 2002–2004 and 2006–2008. Overall the risk of ASD increased 52.9 % from 2002–2004 to 2006–2008. However, the magnitude of change in risk was not uniform across the study area; while some areas experienced dramatic increases in ASD risk (>400 %), others experienced slight decreases. Generally, areas with the lowest risk in 2002–2004 experienced the greatest increases over time. Education and outreach efforts in North Carolina expanded during this period, possibly contributing to the observed leveling of risk over time.
Choroid Plexus Infarction in a Child

Infarction of the choroid plexus of the lateral ventricle is a rare condition, and was not previously described in a child. We describe an infarction of the choroid plexus of the lateral ventricle in a 10-year-old girl, diagnosed upon diffusion-weighted imaging. An infarction of the choroid plexus of the lateral ventricle suggests an embolic or occlusive stroke of the medial posterior choroidal artery.
Mode III Crack Tip Plastic Zone Solution for Work Hardening Solid Using Dislocation Motion

The analysis is based on a shifting center, cylindrical coordinate system. The nonredundant dislocation density is determined. The ratio of nonredundant to redundant dislocation density within the plastic zone may be a useful measure for placing cracks into a brittle class, a ductile class and semibrittle to semiductile classes
Energy Release Rate Prediction in Stiffened-skin Structure Using a Three-dimensional Crack Tip Element Analysis

Total energy release rates and energy release rate components are predicted for a stiffened-skin structure that is loaded in bending and which contains a delamination between its skin and a hat-sha...
Development of Near Surface Models In Saudi Arabia For Low Relief Structures And Complex Near Surface Geology

In the past the geologic information of the near surface in Saudi Arabia was not as critical an issue due to the fact that the prospective geologic structures tended to be much larger than the near surface statics variation. Today, the majority of the prospects are lower relief structures. The static corrections in the near surface statics can include medium to long wavelength statics up to +/80 ms in most prospective areas in Saudi Arabia. Several approaches have been developed to resolve these near surface issues and to better image these low relief structures. These methods are the frozen model, layer modeling and geostatistics. Using these various methods the static uncertainty is reduced in the near surface which in turn gives a more accurate sub-surface image.
Thermomechanical response and stress analysis of copper interconnects

This study is devoted to thermomechanical response and modeling of copper thin films and interconnects. The constitutive behavior of encapsulated copper film is first studied by fitting the experimentally measured stress-temperature curves during thermal cycling. Significant strain hardening is found to exist. Within the continuum plasticity framework, the measured stress-temperature response can only be described with a kinematic hardening model. The constitutive model is subsequently used for numerical thermomechanical modeling of Cu interconnect structures using the finite element method. The numerical analysis uses the generalized plane strain model for simulating long metal lines embedded within the dielectric above a silicon substrate. Various combinations of oxide and polymer-based low-k dielectric schemes, with and without thin barrier layers surrounding the Cu line, are considered. Attention is devoted to the thermal stress and strain fields and their dependency on material properties, geometry, and modeling details. Salient features are compared with those in traditional aluminum interconnects. Practical implications in the reliability issues for modern copper/low-k dielectric interconnect systems are discussed.
Dual-Pulse LIBS Using a Pre-Ablation Spark for Enhanced Ablation and Emission

In this paper we report the first observations of dual-pulse laser-induced breakdown spectroscopy (LIBS) signal enhancements by using a pre-ablation spark. In this technique a laser pulse is brought in parallel to the sample surface and focused a few millimeters above it to form an air plasma or air spark. A few microseconds later a second laser pulse, which is focused on the sample, ablates sample material and forms the LIBS plasma from which analyte emission occurs. In this way, large LIBS signal enhancements, 11- to 33-fold, are observed for copper and lead, respectively, relative to the signal in the absence of the air spark. In all cases where enhanced LIBS signals are seen, greatly enhanced sample ablation also occurs.
Layered perovskite GdBaCoFeO5+x as cathode for intermediate-temperature solid oxide fuel cells

Abstract A layered perovskite oxide, GdBaCoFeO5+x (GBCF), was investigated as a novel cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs). A laboratory-sized Sm0.2Ce0.8O1.9 (SDC)-based tri-layer cell of NiO–SDC/SDC/GBCF was tested under intermediate-temperature conditions of 550–650 °C with humidified H2 (∼3% H2O) as a fuel and the static ambient air as oxidant. A maximal power density of 746 mW cm−2 was achieved at 650 °C. The interfacial polarization resistance was as low as 0.42, 0.18 and 0.11 Ω cm2 at 550, 600 and 650 °C, respectively. The experimental results indicate that the layered perovskite GBCF is a promising cathode candidate for IT-SOFCs.
Stimulation of topoisomerase II-mediated DNA damage via a mechanism involving protein thiolation.

The breakage/reunion reaction of DNA topoisomerase II (TOP2) can be interrupted by DNA intercalators (e.g., doxorubicin), enzyme binders (e.g., etoposide), or DNA lesions (e.g., abasic sites) to produce TOP2-mediated DNA damage. Here, we demonstrate that thiol alkylation of TOP2 can also produce TOP2-mediated DNA damage. This conclusion is supported by the following observations using purified TOP2: (1) Thiol-reactive quinones were shown to induce TOP2-mediated DNA cleavage. (2) Thiol-reactive compounds such as N-ethylmaleimide (NEM), disulfiram, and organic disulfides [e.g., 2,2'-dithiobis(5-nitropyridine)] were also shown to induce TOP2-mediated DNA cleavage with similar reaction characteristics as thiol-reactive quinones. (3) TOP2-mediated DNA cleavage induced by thiol-reactive quinones was completely abolished using mutant yeast TOP2 with all cysteine residues replaced with alanine (cysteineless TOP2). These results suggest the possibility that cellular DNA damage could occur indirectly through thiolation of a nuclear protein, TOP2. The implications of this reaction in carcinogenesis and apoptotic cell death are discussed.
Inequalities for the interpolation points in Chebyshev approximation by polynomials

Letf andg be approximated in the Chebyshev sense by polynomials of degree ?n and ?n?1, respectively. It is shown that if the sum and difference of the normalized (n+1)-st derivatives off andg do not change sign, then the interpolation points ofg separate those off. A corollary is that the zeros of the Chebyshev polynomialT n separate the interpolation points off iff (n+1) does not change sign. The sharpness of this result is demonstrated.
Effects of topically administered ouabain on aqueous humor dynamics

Repeated topical administration of ouabain has been shown to induce a hypodynamic state in both normal and buphthalmic rabbit eyes. The fall in intraocular pressure is greater with increasing concentrations of ouabain. When 0·25% or 0·125% ouabain solutions are used on buphthalmic rabbits, a lowering of the intraocular pressure is observed within 2 hr. This effect persists for about 3 days. Responsiveness does not appear reduced when tests are repeated frequently in the same animal. The histological evidence in buphthalmic eyes suggests that the elevated intraocular pressure in these eyes is most likely related to a deficient drainage mechanism and that lowering of the intraocular pressure by a drug such as ouabain is due, primarily, to an inhibition of aqueous humor secretion.
The Journey of Self-Authorship: Why Is It Necessary?.

This chapter presents the need for the journey of self-authorship and an overview of key concepts and terms explored in this volume.
DNA looping provides for "intersegmental hopping" by proteins: a mechanism for long-range site localization.

Abstract Studies on how transcription factors and DNA modifying enzymes passively locate specific sites on DNA have yet to be reconciled with a sufficient set of mechanisms that can adequately account for the efficiency and speed of this process. This is especially true when considering that these DNA binding/modifying proteins have diverse levels of both cellular copy numbers and genomic recognition site densities. The monomeric bacterial DNA adenine methyltransferase (Dam) is responsible for the rapid methylation of the entire chromosome (with only ~ 100 Dam copies per cell) and the regulated methylation of closely spaced sites that controls the expression of virulence genes in several human pathogens. Provocatively, we find that Dam travels between its recognition sites most efficiently when those sites are ~ 500 bp apart. We propose that this is manifested by Dam moving between distal regions on the same DNA molecule, which is mediated by DNA looping, a phenomenon we designate as intersegmental hopping. Importantly, an intermediate found in other systems including two simultaneously bound, looped DNA strands is not involved here. Our results suggest that intersegmental hopping contributes to enzymatic processivity (multiple modifications), which invoke recent reports demonstrating that DNA looping can assist in site finding. Intersegmental hopping is possibly used by other sequence-specific DNA binding proteins, such as transcription factors and regulatory proteins, given certain biological context. While a general form of this mechanism is proposed by many research groups, our consideration of DNA looping in the context of processive catalysis provides new mechanistic insights and distinctions.
Geometrically Degenerate Solutions of the Kilmister-Yang Equations

I solve, in principle, the Kilmister-Yang equations for the degenerate cases of conformal flatness and decomposability of space-time. The unphysical metrics discussed by Pavelle belong to these degenerate classes. Perhaps using the methods outlined here it will be possible to determine if these "unphysical" metrics are isolated examples or if they are typical of such "geometric-degenerate" classes.
The intersystem crossing process in symmetric tetrachlorobenzene

The ratios of the intersystem crossing rates to the different zero-field (zf) levels of the lowest triplet state of 1,2,4,5 tetrachlorobenzene in durene at 1.6°K are determined using phosphorescence-microwave double resonance techniques. The S1 T1 nonradiative process is at least an order of magnitude faster to the top two zf levels than to the bottom level (τN). This result rules out direct spin-orbit interaction as a dominant mechanism for the intersystem crossing processes in this molecule and suggests that vibronic interaction (in the form of spin-orbit-vibronic or spin-vibronic) must be invoked for the intersystem crossing process from the lowest singlet state of the system studied. The S1 T1 intersystem crossing process in benzene and other aromatic hydrocarbons is briefly discussed.
Membrane Pores Induced by Magainin

Magainin, found in the skin of Xenopus laevis, belongs to a broad class of antimicrobial peptides which kill bacteria by permeabilizing the cytoplasmic membrane but do not lyse eukaryotic cells. The 23-residue peptide has been shown to form an amphiphilic helix when associated with membranes. However, its molecular mechanism of action has been controversial. Oriented circular dichroism has detected helical magainin oriented perpendicular to the plane of the membrane at high peptide concentrations, but Raman, fluorescence, differential scanning calorimetry, and NMR all indicate that the peptide is associated with the head groups of the lipid bilayer. Here we show that neutron in-plane scattering detects pores formed by magainin 2 in membranes only when a substantial fraction of the peptide is oriented perpendicular to the membrane. The pores are almost twice as large as the alamethicin pores. On the basis of the in-plane scattering data, we propose a toroidal (or wormhole) model, which differs from the barrel-stave model of alamethicin in that the lipid bends back on itself like the inside of a torus. The bending requires a lateral expansion in the head group region of the bilayer. Magainin monomers play the role of fillers in the expansion region thereby stabilizing the pore. This molecular configuration is consistent with all published magainin data.
Erythropoietin in Human Milk: Physiology and Role in Infant Health

Human milk contains substantial concentrations of erythropoietin, a hormone best known for its role in the regulation of erythropoiesis. Recent studies show that erythropoietin receptors are widely distributed in human tissues, including the gastrointestinal tract, endothelial cells, spinal cord, and brain, suggesting that erythropoietin plays a wider role in infant development. Mammary epithelial cells contribute to the production of erythropoietin in human milk, and erythropoietin concentrations appear to rise slowly in human milk during the first few months of lactation. Current data suggest that erythropoietin in human milk may play a pleiomorphic role in erythropoiesis, neurodevelopment, maturation of the gut, apoptosis, and immunity in the infant.
Papillary cystadenocarcinoma of the ovary

Abstract The subject of papillary cystadenocarcinoma of the ovary has been considered and the more recent English literature reviewed. Thirty case records have been studied, five of these being presented in detail. Papillary cystadenocarcinoma is a malignant tumor which usually metastasizes so early that the condition is far advanced before the patient seeks aid. The average age at which it occurs is approximately fifty years. It is slightly more common in parous than in nulliparous women. Pain and a tumor mass are the predominating symptoms and findings. Over 50 per cent are bilateral when treatment is first undertaken. The growth of the tumor is rapid and metastasis is first to the opposite ovary, then to the uterus, peritoneum and other abdominal organs. Recurrence after removal is common. Malignant cells recovered from the ascitic fluid aid in the diagnosis and also the planning of a proper course of treatment which consists of operative removal followed by roentgenotherapy in the average patient. Surgery should aim to remove all the pelvic generative organs. Radiation should include the entire abdominal cavity. The effect of radiation is not constant in all patients. Following the removal of the primary growth, the secondary growths may disappear of themselves. The prognosis is extremely poor but should not keep the surgeon from doing all possible to alleviate the patient. Many patients go without recurrence for years after adequate treatment. Most of the patients from this Clinic that received roentgenotherapy were far advanced at the time of the first examination.
Determination of 3JHF and 4JHF Karplus relationships for the .vphi. and .psi. angles of peptides using N-fluoroamides as models

Etude par spectrometrie RMN de 1 H, 19 F, 13 C d'amides cycliques, N-fluoro dans le but de determiner les angles φ'( 3 JHF) et ψ'( 4 JHF) de peptides
Cost and other barriers to public access computing in developing countries

Public access to computers and the Internet can play an important role in social and economic development if it effectively helps to meet the needs of underserved populations. Public access venues such as libraries, telecentres and cybercafes are sometimes free, and sometimes charge user fees. User fees can be an important barrier to use of public access venues, especially among underserved communities in developing countries. This paper analyzes the role of user fees and other critical barriers in the use of computers in public access venues in 25 developing countries around the world. Results of this study suggest that digital literacy of staff and local relevance of content may be more important than fees in determining user preference for public access venues. These findings are important to public libraries, which tend to offer free services, but where perceptions of digital literacy of staff and locally relevant content tend to be lowest, compared to telecentres and cybercafes, according to the results of this study. More attention to digital literacy of staff and availability of locally relevant content may be more important than free services to meet the information needs of underserved populations.
Crystallization behaviour of poly(ether-ether-ketone)

Abstract A study has been made of the crystallization behaviour of poly(ether-ether-ketone), PEEK, under isothermal and non-isothermal conditions. A differential scanning calorimeter was used to monitor the energetics of the crystallization process from the melt and from the rubbery amorphous state. During isothermal crystallization, relative crystallinity develops with a time dependence described by the Avrami equation, with exponent n = 3. Greater absolute crystallinity develops during melt crystallization, nearly twice that which develops from the rubbery state, for comparable rates of crystallization. For non-isothermal studies, amorphous films were crystallized by heating or cooling at rates from 1°C/min to 50°C/min. A large fraction of crystallinity, from 0.45 to 0.70, develops by secondary processes. A kinetic treatment based on the Avrami equation is presented to describe the primary processes leading to non-isothermal crystallization. We have calculated activation energies of 68 kcal mol−1 for crystallization from the melt, and 52 kcal mol−1 for crystallization from the rubbery amorphous state. Results of isothermal and non-isothermal crystallization of PEEK are compared with those of poly(ethylene terephthalate).
A new type of transducer for partial pressure control

Abstract A new transducer for controlling the partial pressure of sputtering gases is described. Utilizing the electron impact emission spectroscopy (EIES) principle, an instrument capable of operating in a total pressure environment of 100 x 10 -3 Torr or more with minimum detectable partial pressures to 10 -7 Torr is described. These capabilities seem ideal for controlling reactive deposition processes utilizing N 2 , O 2 or hydrocarbons. Because of the high operating pressure capabilities, this transducer does not require the complication of high vacuum pressure reduction and thus eliminates a major source of unscheduled maintenance. The operating principles of EIES and the sensitivities that were determined for the various gases tested are described in this paper. The present authors have found the technique to have high stability over extended periods of time (about ±3.5% over 30 days) and sufficient sensitivity to control processes of present practical interest. In addition to the use for direct partial pressure control the technique has utility for monitoring common residual gases such as H 2 O and CO 2 , in an analyzer mode, as a precursor to starting the reactive process.
Specific features of the oxidation of complex titanium alloys in the as-cast and recrystallized states

We study the heat resistance of complex titanium alloys with 4.5-11 wt.% Al in the as-cast and recrystallized states at a temperature of 800°C for 50 h. It is shown that the procedure of alloying has the same influence on the as-cast and recrystallized metals, and the initial structure affects the kinetics of oxidation of the latter. In this case, the ground recrystallized structure promotes the formation of oxide films with high adhesive strength guaranteeing high levels of the heat resistance of the alloy for long periods of holding.
A program for the analysis and design of general dynamic mechanical systems

The physical laws that govern motion of individual components of mechanical assemblages are well-known. Thus, on the face of it, the concept of a general computer-aided-design program for mechanical system design appears straightforward. However, both the equation formulation and the numerial solution of these equations pose challenging problems for dynamic systems: the former when three-dimensional effects are important, and the latter when the equations become "stiff" or when different types of analyses are to be performed.
Illicit worlds of Indian dance: cultures of exclusion, by Anna Morcom, New York, Oxford University Press, 2013, 286 pp., US$30 (paperback), ISBN 978-0199343546

Illicit Worlds of Indian Dance examines the hidden histories and communities of female and transgender erotic dancers and the rise of Bollywood dance in contemporary India. These hereditary communi...
Athletic injuries to the abdomen and thorax.

Abstract The practical surgical management of patients with abdominal and thoracic injuries due to sports will be the same as that for patients with similar injuries from other trauma. It is not unusual to see serious abdominal injury following an automobile accident. The same awareness that serious abdominal and thoracic injury can occur in sports is important. Although abdominal injury due to athletics is less common, the same problems in examination and management of the patient arise. Minor injuries to the abdominal and thoracic walls may be treated by rest, immobilization by strapping, the application of heat and massage, or the local injection of anesthetic. When intra-abdominal and intrathoracic injury are suspected the athlete should be hospitalized for careful observation. When visceral injury is found to occur, its treatment does not differ from similar injuries due to other causes.
Soil fertility distributions in long-term no-till, chisel/disk and moldboard plow/disk systems

In permanent no-till (NT), soil nutrients are no longer mixed into the topsoil as with moldboard plow/disking (MD), whereas chisel/disking (CD) does limited mixing. Surface broadcast and/or banded nutrient applications may result in high and low fertility zones in permanent NT, with possible implications for soil sampling and nutrient placement. We investigated effects of 25 years of continuous NT, CD and MD with corn planted in the same row locations on organic matter (SOM), pH-H2O and Mehlich-3 extractable phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg). Vertical distribution at 0–5, 5–10 and 10–15 cm depths was measured as well as horizontal distributions across corn rows. We observed higher SOM and P in NT and CD than in MD in the 0–15 cm layer. SOM content was greatest in the top 5 cm in NT, but declined sharply with depth. SOM content in CD was not as high at the surface as in NT, but did not decline as fast as in NT. SOM was uniform but low throughout the 0–15 cm depth of MD. In all tillage systems, SOM did not vary across rows. Soil pH was higher in the 0–5 cm layer of NT than the deeper layers but the reverse was true in the CD or MD treatments. Concentrations of P, K and Ca were higher in the surface 0–5 cm than 10–15 cm depth of all tillage systems, but most strikingly in NT and CD. Starter fertilizer injection resulted in higher P and lower pH in the injection zone of all tillage treatments, but most notably in NT. The pH was depressed under the band of side-dressed nitrogen with all tillage systems. Potassium accumulated in the rows of the previous crop, probably because it leached from crop residue that accumulated there. Tillage did not affect Mg distribution. Optimal nutrient management in NT should take account of horizontal and vertical nutrient and pH distributions. Samples in long-term NT could potentially be taken to a shallower depth if calibration curves are available. To avoid underestimating P and K availability or overestimate lime needs, high P or decreased pH bands should be avoided, as well as crop rows. Possibilities to reduce P and K applications with banding need more investigation. Results show the importance of regular liming in NT to maintain surface pH in the optimum range, but also show that lime does not have to be incorporated.
Effect of parathyroidectomy on osteoporosis and bone metabolism

The presentation of patients with hyperparathyroidism has changed over the past decades with the routine use of multichannel serum electrolyte analyzers. Serum calcium abnormalities rather than overt symptoms prompt the evaluation for suspected hyperparathyroidism. It is rare to see a patient with cystic bone changes; instead it is more common to have subtle bone loss identified in the evaluation of bone mineral density. Parathyroidectomy is recommended in patients with osteoporosis. Since the effect of parathyroid hormone on bone is complex, the changes in bone metabolism following parathyroidectomy and the effect of parathyroidectomy on fracture risk are important factors to consider. Studies have yielded conflicting results regarding the questions of bone density and fracture risk, limited by small sample size and short follow-up periods. Recent investigations describe a subset of patients with bone disease that may benefit from early surgical intervention.
New clinical and radiographic signs in ischemic colitis.

Summary The clinical manifestations of ischemic colitis typically include bloody diarrhea, crampy lower abdominal pain, and abdominal distention. Occlusion of the arterial blood supply of the colon may or may not be present. Low flow states due to either hypovolemia or cardiac problems are apparently equally important. A review of the literature did not disclose any other causes for slough of long continuous segments of colonic mucosa. This is considered a specific sigmoidoscopic and radiographic sign of ischemic colitis.
Composites of starch and poly(ethylene‐co‐acrylic acid). Complexing between polymeric components

Extrusion-blown film prepared from a semidry mixture of starch and poly(ethylene-co-acrylic acid) (EAA) cannot be sharply separated into its polymeric components by selective solvent extraction, and the two polymers have the outward appearance of being compatible. Also, the starch portion is resistant to enzyme attack, and starch domains are not visible by SEM. Further studies were therefore made on the starch–EAA system to determine reasons for the apparent compatibility between the two polymers, and evidence for polymer complex formation was obtained. Combination of aqueous ammonia solutions of starch and EAA led to an increase in viscosity, and a coprecipitate of starch and EAA separated from solution. Moreover, solvent extraction would not separate physical mixtures of starch and EAA prepared from aqueous solutions. Although both the linear (amylose) and branched (amylopectin) components of starch formed an apparent complex with EAA, a low molecular weight starch fraction and a high molecular weight dextran (a polysaccharide with α-(16) linked glucopyranosyl units) did not. These observations support the theory that a helical inclusion complex is formed from starch and EAA, which is similar to the well-known complexes produced from starch and fatty acids.