cssi/SciSciGPT-SciSciNet huggingface dataset:
About the strangeness of leptons

Abstract Two versions of the universal Fermi interaction are compared. The first is the current-current interaction in a form suggested by the formalism developed previously by the author 5). The second satisfies the overall rule |ΔS| = 1 (S is the total strangeness of leptons, baryons and mesons) and has a form suggested also by the mentioned formalism. In the second interaction, pairing of leptons depends, owing to the |ΔS| = 1 rule, on the relative strangeness of the other pair of particles coupled to these leptons (cf. ref.10)). This second interaction cannot be transmitted by an intermediate vector field. In both cases leptonic Λ-decay rates are diminished compared to the original Gell-Mann-Feynman theory. In the second case these rates may easily be reduced to 1 10 of the original values. If the second interaction would be valid, the rule |Δ| = 1 wouldbe a general property of both leptonic and non-leptonic weak processes (cf. ref. 6)). No progress, however, has been achieved by using this interaction towards explaining non-leptonic weak processes in terms of the universal Fermi interaction. A Fermi interaction consistent with the isobar and parity properties of non-leptonic hyperon decays is given.
Atomic ordering effect on SiGe electronic structure

In this paper, a realistic atomic model is used to study the atomic ordering effect on electronic structures of Si 0.5 Ge 0.5 . The hybrid density functional theory (DFT), HSE06, is chosen as the methodology. The calculated bandgap and effective masses of Si and Ge at various symmetry points are first validated by the reported experimental data and empirical pseudo-potential method (EPM) calculations. The study of two different Si 0.5 Ge 0.5 atomic configurations shows that the SiSi-GeGe case is more stable than SiGe-SiGe (RS2 structure). In addition, the electron effective masses of the former one are larger than those of the latter one, and those calculated by EPM with virtual crystal approximation (VCA). This large electron effective mass is attributed to the localized electron orbital of the lowest anti-bonding state in the SiSi-GeGe case which leads to a flat E-k curve. However, no obvious ordering effect on hole effective mass is found.
Perinatal stress and early life programming of lung structure and function.

Abstract Exposure to environmental toxins during critical periods of prenatal and/or postnatal development may alter the normal course of lung morphogenesis and maturation, potentially resulting in changes that affect both structure and function of the respiratory system. Moreover, these early effects may persist into adult life magnifying the potential public health impact. Aberrant or excessive pro-inflammatory immune responses, occurring both locally and systemically, that result in inflammatory damage to the airway are a central determinant of lung structure–function changes throughout life. Disruption of neuroendocrine function in early development, specifically the hypothalamic–pituitary–adrenal (HPA) axis, may alter functional status of the immune system. Autonomic nervous system (ANS) function (sympathovagal imbalance) is another integral component of airway function and immunity in childhood. This overview discusses the evidence linking psychological factors to alterations in these interrelated physiological processes that may, in turn, influence childhood lung function and identifies gaps in our understanding.
LINEAR MAGNETORESISTANCE CAUSED BY THE INTERFERENCE OF OPEN ORBITS

We find that the interference of two open orbits modeled by two noncollinear cylindrical Fermi surfaces leads to a linear magnetoresistance. The interference occurs only when the magnetic field is slightly tilted from the perpendicular to the plane defined by the cylinders’ axes. There exist experimental data which reveal a linear magnetoresistance. Some may possibly be explained by the interference effect.
The dynamics of flexible multibody systems: A finite segment approach—I. Theoretical aspects

Abstract Modelling the dynamics of flexible multibody systems is a difficult problem. There has been much discussion about how to approach this problem. This paper presents a method in which the flexibility may be included in the dynamical analysis. The method has distinct advantages over other proposed methods. The dynamical formulation is based on Kane's equations. The flexibility is modelled by using springs and dampers at the joints of the system. The stiffness and damping coefficients of these are found using the physical properties of the members. These are then incorporated into the equations of motion. Part I of this paper discusses the theoretical aspects of this type of analysis, while part II shows two example problems.
Long oblique distal osteotomy of the fifth metatarsal for correction of tailor's bunion: a retrospective review.

Abstract A long-term retrospective review of a long oblique distal osteotomy of the fifth metatarsal for correction of a tailor's bunion deformity is presented. The technique, results, and follow-up of this procedure are described. The long oblique distal osteotomy was performed on 25 feet on 16 patients. Follow-up ranged from 11 to 110 months with an average of 64.4 months. The average preoperative intermetatarsal 4-5 angle and lateral deviation angle improved from 10.88° and 4.24°, respectively, to 5.52° and −4.24° postoperatively, respectively. A modified scoring scale for lesser metatarsal procedures was used, showing an average postoperative score of 94 out of 100 possible points. Subjectively, 96% (24 of 25) of feet that underwent surgery were rated as excellent or good. Complications included one patient with paresthesias, one soft-tissue infection, and 2 patients had irritation from screws. The authors conclude that the long oblique distal osteotomy is a viable alternative in the correction of tailor's bunion deformity. (The Journal of Foot & Ankle Surgery 42(1):36–42, 2003)
Bradykinin B2 receptor signaling: Structural and functional characterization of the C-terminus

Over the last few years the importance of the intracellular C-terminus in the signaling of G-protein coupled receptors (GPCR) has become increasingly evident. In an effort to provide a structural framework for biological function, we have determined the conformation of the C-terminus of the bradykinin (BK) B2 receptor. Using a uniformly 15N- and 13C-enriched sample of the BKB2 receptor [309–366], NMR results clearly define three α-helices lying on the zwitterionic surface of the dodecylphosphocholine. The proximal helix consisting of residues 311–326 was previously predicted based on homology modeling with rhodopsin. This corresponds to what is often called helix-8 of the GPCRs. The two distal helices, residues 333–345 and 348–363, are clearly borne out by the NMR data. The functional importance of these secondary structural elements was probed by determination of the signaling properties (inositol phosphate formation) of mutant BKB2 receptors lacking the domains (deletion mutants) or containing the corresponding region from the related GPCR, angiotensin II AT1a (chimera receptors). We demonstrate that the regions between the helices (residues 327–333 and 346–347) can be exchanged without loss of signaling. In contrast, modification of the three helices, particularly the hydroxyl-containing residues, has drastic effects on the signaling profile of the BKB2 receptor. By coupling of the structural features with the functional data, the molecular mechanisms of signaling by the BKB2 receptor are beginning to be established.© 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2005
Antiviral effects of mifepristone on human immunodeficiency virus type-1 (HIV-1): Targeting Vpr and its cellular partner, the glucocorticoid receptor (GR)

The HIV-1 viral protein R, Vpr, increases virus replication in T cells and is necessary for the optimal infection of primary monocytes/macrophages and other non-dividing cells. Vpr interacts with the cellular glucocorticoid receptor (GR) and transactivates the HIV-1 LTR through glucocorticoid response element (GRE), an event that can be blocked by the GR antagonist, mifepristone. Results demonstrated that Vpr-induced transactivation of the HIV-1 LTR was inhibited by mifepristone in a dose-dependent manner by >60% at a 10 microM concentration. Infectivity assays using X4 and R5 viruses demonstrated antiviral effects on a dose-dependent regimen of mifepristone. The effects of mifepristone were also tested in latently infected cells that could be activated with extracellular Vpr protein and results indicated specific inhibition of virus reactivation in the presence of this antagonist.
Mode Damping in NAL Main Ring Accelerating Cavities

The application of a ferrite with strong dispersion of magnetic loss tangent to control the impedance of undesired modes in the main ring cavities of the National Accelerator Laboratory synchrotron is described. The impedances of 17 of 21 modes in the frequency range of interest have been damped to less than 0.5 percent of the main mode impedance. On the basis of low level measurements, the dissipation added due to mode damping is 2 kW for operation at a 200 kV gap voltage.
Comment on “time evolution of non-photochemical hole burning linewidths: Observation of spectral diffusion at long times”

Justification for the distribution function f(R) of relaxation rates used by Littau, Bai and Fayer to describe spectral diffusion of non-photochemical holes is provided in terms of a physical model based on tunneling of glass two-level systems. A Gaussian distribution function for the tunnel parameter leads directly to f(R). Earlier utilization of the latter function is noted.
High-density and low-density capsule production byStreptococcus zooepidemicus

A group C streptococcus (Streptococcus zooepidemicus), isolated from the blood of a 79-year-old man who succumbed to infection, was examined for animal virulence, reactivity in an in vitro phagocytic assay, and the production of antiphagocytic structures. Initial examination of the clinical isolate by electron microscopy revealed the presence of high-density (HDC) and low-density (LDC) capsule variants. The HDC variant capsular material could be removed from the cell wall by hot acid extraction or obtained from the supernatant fluids when the organisms were grown in a defined medium. The capsular material was purified by ion-exchange chromatography on diethylaminoethyl cellulose and gel filtration on Sepharose 4B and was shown to be composed largely of a high molecular weight hyaluronic acid. Both the high-density and low-density capsule variants were shown to be mouse virulent with lethal dose 50 (LD50) values of 3.7×104 colony-forming units (CFU) and 3.3×105 CFU, respectively. Opsonophagocytic assays with human peripheral polymorphonuclear leukocytes demonstrated that only the LDC organism could be phagocytized and killed in the presence of white blood cells, specific antibody, and complement.
Workload distribution of discrete‐time parallel queues with two servers

We study discrete-time, parallel queues with two identical servers. Customers arrive randomly at the system and join the queue with the shortest workload that is defined as the total service time required for the server to complete all the customers in the queue. The arrivals are assumed to follow a geometric distribution and the service times are assumed to have a general distribution. It is a no-jockeying queue. The two-dimensional state space is truncated into a banded array. The resulting modified queue is studied using the method of probability generating function (pgf) The workload distribution in steady state is obtained in form of pgf. A special case where the service time is a deterministic constant is further investigated. Numerical examples are illustrated. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 440–454, 2000
Rate and duration of seed component accumulation in water-stressed soybean.

Lack of adequate soil moisture during seed filling limits seed size in soybean [Glycine max (L.) Merr.], generally by shortening the duration of seed fill. Seed growth rate typically remains largely unaffected. The smaller seeds often have increased seed protein concentration due to less detrimental effect on final protein accumulation relative to other major seed components. Such changes in seed composition despite stable rates of seed filling suggest compensation may occur among component accumulation rates or the duration of accumulation of individual seed components is affected differentially by water stress. We examined these possibilities by evaluating the rates and durations of protein, oil, and residual accumulation in two soybean lines subjected to limited soil moisture during seed filling. Results indicated that both responses (rate and duration of accumulation) to water deficit can occur. The rates of accumulation of the different seed components often compensated, resulting in a constant seed growth rate, typically favoring protein accumulation. To our knowledge, this is the first demonstration of a differential response among rates and durations of seed component accumulation when soil moisture becomes limiting. The relative stability of protein accumulation likely reflects the availability of remobilizable N late in seed filling and the dependence of oil accumulation on current photosynthesis.
Habit reversal vs. negative practice treatment of nailbiting

Abstract A previous study of the habit reversal treatment of nailbiting was extended by using more subjects (97) and a comparison with an alternative method (negative practice). Negative practice reduced nailbiting episodes by about 60% whereas habit reversal reduced nailbiting episodes by about 99% throughout the 5-month follow-up.
Instrumentation For Measuringdirect And Diffuse Insolation In Testing Thermal Collectors

AbstractThe efficiencies of thermal collectors are traditionally expressed with respect to the total (direct beamplus diffuse) insolation at the collector plane. Evaluation of the performance of concentrating collectors,however, requires, in addition, a knowledge of the insolation which is within the angular field of view of the collector. The use of pyranometers to measure the total insolation as well as the insolation within speci-fied angular fields of view, together with a normal incidence pyrheliometer to measure the direct beam compo-nent, is described. The instrument calibration procedure is discussed, and several data are presented. Introduction A determination of the efficiency of a solar collector comprises simultaneous measurements of the rate atwhich useful energy is being extracted from the collector and the rate at which solar energy is being inter-cepted by the collector. The latter measurement must be carefully considered for meaningful test results.In the simplest case, flat plate collectors are nondirectional, and measurements of the total insolation atthe plane of the collector using a pyranometer suffice. On the other hand, concentrating collectors possessrestricted angular fields of view. Focusing concentrators image the solar disk, and hence can utilize onlythe direct beam radiation effectively. In the plane perpendicular to the long axis of a two -dimensionalparabolic trough, for example, the angular field of view is approximately the e subtended by the sun.
The Origin of Adaptations

LAST December, before the American Society of Zoologists, Prof. M. F. Guyer delivered an admirably lucid and well-reasoned address entitled “Soma and Germ”. Near the end he says (American Naturalist, March-April, 1925):
Unilateral subdural hematoma without midline shift

Abstract Two cases of radiographically isodense subdural hematoma are presented in which absence of displacement of midline cerebral structures was due not to bilateral lesions, but rather to “balancing” of the volumetric effect of a unilateral lesion by preexisting encephalomalacia. Attention to the past medical history and the computed tomography scan which showed evidence of unilateral loss of brain substance led to the proper diagnosis.
Rat brain hexokinases of two different molecular sizes

Abstract Two different molecular species of particulate hexokinase (ATP: d -hexose 6-phosphotransferase, EC 2.7.1.1) from rat brain were separable by gel filtration. The higher-molecular weight hexokinase (hexokinase-H) was converted to the lower-molecular weight enzyme by treatment with ethanol or by digestion with phospholipase A. The lower-molecular weight hexokinase (hexokinase-L) was converted to hexokinase-H by incubation with lecithin. These results indicate that hexokinase-H is an aggregate of hexokinase-L and phospholipid moieties.
A model for the parasitic SCR in bulk CMOS

A model is presented for the parasitic SCR in bulk CMOS. The model shows the exact way that the shunting resistances alter the terminal V-I characteristics. It describes a negative differential resistance (NDR) range which is the only requirement for latch-up if certain biasing conditions are met. The NDR region will start when the product of current and shunting resistance equals the built in voltage and will occur for a n + a p n β p < 1). The conditions for the center junction to become forward biased are given. If these conditions are met, the SCR will latch-up. If these conditions are not met, latch-up becomes dependent on the biasing circuit.
FACULTY PARTICIPATION IN UNIVERSITY GOVERNANCE: AUSTRALIA AND THE UNITED STATES

Written originally as a lecture for American students of tertiary educational administration, this essay traces the historical development of lay boards governing American universities and compares this with the current practice at an Australian university. The increasing influence of governmental bureaucracies in both countries is highlighted. The author, an American professor teaching as a visitor in Australia, takes a second look at the American policy of excluding faculty from governing boards. The presence of faculty members on the board could be a bulwark in the defense of academic freedom and institutional excellence.
Water-soluble xanthobilirubinic acids?

Xanthobilirubinic acid, a model dipyrrinone for one-half of the bilirubin molecule in photochemical and metabolism studies, is more polar than bilirubin and insoluble in water and in chloroform. Replacing the β-alkyl substituents on the lactam ring of xanthobilirubinic acid with methyl-capped ethylene glycol, diethylene glycol, and triethylene glycol (PEG) groups steadily increased the water solubility of the pigment so that the last is completely soluble in both water and chloroform. Synthesized by base-catalyzed condensation of the corresponding methyl-capped 3,4-diPEG-pyrrolin-2-one with 3,5-dimethyl-4(2-ethoxycarbonylethyl)-2-formyl-1H-pyrrole, these new PEGylated analogs of xanthobilirubinic acid are yellow-colored dipyrrinones that form intermolecular hydrogen-bonded dimers in chloroform solution but are monomeric in methanol and water, as revealed by 1H NMR spectroscopy and vapor pressure osmometry. Methyl xanthobilirubinate has served as a synthetic precursor to bilirubinoids; its amphiphilic PEGylated analogs suggest a route to water-soluble bilirubinoids and biliverdinoids.
INTERFEROMETRIC MEASUREMENT OF INSTANTANEOUS LOCAL HEAT TRANSFER FROM A HORIZONTALLY VIBRATING ISOTHERMAL CYLINDER

Abstract Local instantaneous heat-transfer coefficients were measured for free convection from an isothermal cylinder vibrating sinusoidally in a horizontal plane. The results show that the heat-transfer coefficient is strongly dependent upon the ratio of amplitude of vibration to cylinder diameter, A D . For values of A D less than approximately 0·25, a critical vibration intensity was observed below which vibration caused only small increases in the heat-transfer rate; however, at A D greater than 0·25, the critical vibrational intensity did not appear to exist because the heat transfer from the cylinder increased as soon as the vibrational speed increased from zero. A correlation of the data is presented which predicts the increase in average heat transfer from the cylinder to air above the free convective rate. The correlation also applies to data for much larger vibrational intensities.
Extrapolation of animal toxicity to humans: Interspecies comparisons in drug development

Different methods for converting the dose-related toxicity of drugs from animals to humans are reviewed. Each method is analyzed with respect to its utility and limitations. Linear extrapolations from animals to humans based on body weight equivalence are shown to be inaccurate unless species-specific conversion factors are used. Extrapolations based on surface area equivalence are more accurate, do not require conversion factors, and may be used when pharmacokinetic data are not available. Ultimately, interspecies conversions are most reliable when pharmacokinetic data are available, assuming that toxic responses are comparable among species for similar blood levels. Two pharmacokinetic-based approaches may be used: direct use of plasma concentration or area under the concentration-time curve (AUC) and physiologically based pharmacokinetic (PBPK) models.
Slowing the Onset of Hypoxia Increases Colony Forming Efficiency of Connective Tissue Progenitor Cells In Vitro.

Abstract Background: Survival and colony formation by transplanted tissue derived connective tissue progenitor cells (CTPs) are thought to be important factors in the success of clinical tissue engineering strategies
A Telling Transition: New Graduate Nursing in the Oncology and Bone Marrow Transplantation Setting

The University of Colorado Hospital's Post-Baccalaureate Nurse Residency Program is a Commission on Collegiate Nursing Education-accredited program structured to provide critical elements important for a successful transition into professional nursing practice. As part of the program, graduate nurse residents receive a year of education that includes 12-24 weeks of precepted orientation on the clinical unit, paid specialty courses, and monthly seminars that provide additional curriculum and mentoring support. At the completion of the program, the residents complete an evidence-based practice project and a clinical narrative summarizing their residency experience. The following is an example of one resident's exemplar.
Structure of aspartate-beta-semialdehyde dehydrogenase from Escherichia coli, a key enzyme in the aspartate family of amino acid biosynthesis.

Aspartate beta-semialdehyde dehydrogenase (ASADH) lies at the first branch point in an essential aspartic biosynthetic pathway found in bacteria, fungi and the higher plants. Mutations in the asd gene encoding for ASADH that produce an inactive enzyme are lethal, which suggests that ASADH may be an effective target for antibacterial, herbicidal and fungicidal agents. We have solved the crystal structure of the Escherichia coli enzyme to 2.5 A resolution using single isomorphous replacement and 3-fold non-crystallographic symmetry. Each monomer has an N-terminal nucleotide-binding domain and a dimerisation domain. The presence of an essential cysteine locates the active site in a cleft between the two domains. The functional dimer has the appearance of a butterfly, with the NADP-binding domains forming the wings and the dimerisation domain forming the body.A histidine residue is identified as a likely acid/base catalyst in the enzymic reaction. Other amino acids implicated in the enzymic activity by mutagenesis are found in the active site region and define the substrate binding pocket.
Picosecond Pulsing And Sampling By GaAs Photodetectors Fabricated On Silicon Substrates

Picosecond photoconductivity by Gallium Arsenide grown directly on silicon and silicon dioxide by Molecular Beam Epitaxy (MBE) has been investigated. Initial results from high speed measurements have demonstrated the potential of this material to achieve sub-10 picosecond recombination lifetimes for photogenerated carriers, while retaining reasonable effective drift mobilities. Thus, photodetectors fabricated from this material can be applied as picosecond pulsing and sampling circuit elements for both silicon and GaAs integrated circuit technologies.
Gender and distributive justice: The influence of gender-related characteristics on allocations

The influence of dispositional and situational gender-related factors on the distributive justice behavior of males and females was examined in this research. Using the self-other allocation paradigm, traditional and andrognyous subjects outperformed traditional or androgynous opposite-sex co-workers (Experiment 1) or same-sex co-workers (Experiment 2). The task gender-linkage and the physical attractiveness of the opposite-sex co-workers were also considered. The results indicated that androgynous persons were more generous in their allocations and were less influenced by the gender-related characteristics of an opposite-sex co-workers than traditional persons. In same-sex dyads, males were more equitable than females and were uninfluenced by gender-related factors. Traditional, but not androgynous, females adjusted their allocation behavior according to the gender-linkage of the task, allocating more equitably on gender-congruent tasks than on gender-incongruent tasks. The significance of these findings to understanding sex differences in distributive justice behavior is discussed.
Lipschitz properties of structure preserving matrix perturbations

Abstract It is proved that, under small perturbations that preserve the Jordan structure, canonical transformation matrices have the Lipschitz property. Analogous result is proved for matrices under additional structure, such as Hamiltonian, skew-Hamiltonian, and symplectic. Both real and complex cases are considered.
Detection of aldolase activity on polyacrylamide gels: application to 2-keto-4-hydroxyglutarate aldolase.

Abstract A method is described for the detection of 2-keto-4-hydroxyglutarate aldolase activity after electrophoresis of the enzyme on polyacrylamide gels. When gels are incubated with substrate (2-keto-4-hydroxyglutarate), activity is seen as a yellow-colored band due to interaction of the product )glyoxylate) with ortho -aminobenzaldehyde and glycine. Positive results have been obtained using either crude cell-free preparations or homogeneous enzyme from Escherichia coli as well as with highly purified samples of aldolase from bovine liver or kidney extracts. The method is potentially applicable to other aldolases that liberate an aliphatic aldehyde as a product; modifications and limitations of the procedure for detecting fructose 1,6-diphosphate aldolase, 2-keto-3-deoxy-6-phosphogluconate aldolase, and 2-deoxyribose-5-phosphate aldolase activities have been explored.
A conjugate matched multiplier having minimum thermal resistance

The impedances of four varactor diodes are conjugately matched at the fundamental and second-harmonic frequencies to allow parallel operation. This arrangement can increase the power output since all diodes have minimum thermal resistance.
Influence of adrenalectomy and cortisone on the anaphylactic heart reaction in rabbits.

Abstract 1.1. Adrenalectomized sensitized animals, kept alive with desoxycorticosterone acetate, which was withdrawn two days prior to anaphylactic reaction, manifested the anaphylactic heart reaction, precipitin titer, and Arthus skin reaction, upon exposure to sensitizing antigen without pronounced differences in intensity as compared to nonadrenalectomized rabbits. 2.2. Cortisone in high dosage given during six hours prior to shocking antigen injection did not demonstrate any inhibitory effect on the intensity and the duration of the EKG changes following horse serum injection. 3.3. In seven sensitized rabbits with daily treatment of cortisone, three demonstrated a reaction and four failed to manifest any noticeable EKG changes following antigen injection. This contrasts to the invariably occurring reaction in animals not treated with cortisone. Both the precipitin titer and the Arthus phenomenon were either inhibited or suppressed. All animals demonstrated the same typical pronounced granulocytopenia following the antigen injection.
Heavy quarks and prompt leptons in p ― p collider jets

(i) Large-transverse-momentum $\stackrel{-}{p}p$ events at $\sqrt{s}=540$ GeV are dominated by two-jet production; the cross section is compatible with the predictions of perturbative QCD. (ii) Large-${p}_{T}$ jets are rich in charm particles. We investigate the implications of these experimental observations. We find a source of heavy quarks and associated prompt leptons which could totally dominate yields conventionally computed from perturbative QCD and which, more importantly, leads to totally different event characteristics. For example, events where both jets contain a heavy-quark fragment ($c\stackrel{-}{c}+c\stackrel{-}{c}$, $c\stackrel{-}{c}+b\stackrel{-}{b}$, or $b\stackrel{-}{b}+b\stackrel{-}{b}$) are the origin of opposite- and same-sign lepton pairs with equal probability. The dileptons are accompanied by four strange particles and occasionally conceal their jet origin by trigger bias. They form a possible source of the "anomalous" dilepton events recently observed by the UA1 experiment.
Simulation of Large Electromagnetic Structures with an Application to Quasi-optical Amplifier

Quasi-optical structures are very large to be simulated using the conventional FDTD techniques. In this paper a combined FDTD/Convolution technique is developed to reduce the computational load in the simulation of such structures. This technique reduces the computational burden by breaking the system into smaler modules each can be characterized by an impulse response matrix. The overa3l system response is then obtained by subsequently interconnecting the individual responses together via a convolution process.
Induction of polyclonal CD8+ T cell activation and effector function by Pertussis toxin

Pertussis toxin (PTX) has pronounced adjuvant activity and strongly enhances innate and adaptive immune responses, including increased antibody production and Th1/Th2 cytokine production. Adjuvant effects of PTX on Th1 and Th2 cells are primarily mediated via CD80/86 costimulation via enhanced expression of these molecules by APCs. However, it has remained unresolved whether PTX modulates the expression of costimulatory and inhibitory molecules on CD4+ and CD8+ T cells. To address this question, we determined the expression kinetics of CD28, CTLA-4, and CD40L on spleen CD4+ and CD8+ T cells after incubation with PTX. The results show that PTX upregulated the expression of CD28 by CD8+ T cells, but not by CD4+ T cells. In contrast, the expression of CTLA-4 and CD40L was not substantially altered on CD4+ or CD8+ T cells. CD28 upregulation by CD8+ T cells was paralleled by upregulation of CD69 and the induction of IFN-γ, Granzyme B (GrB), and IL-17. CD8+ T cell activation and cytokine production could be substantially blocked with anti-CD80 and CD86 antibodies, consistent with CD28 mediated signaling. Treatment of highly purified CD8+ T cells with PTX resulted in upregulation of CD28 and CD69, and production of IFN-γ. Incubation with CD28 mAb further enhanced this effect, suggesting that PTX has direct effects on CD8+ T cells which are enhanced by CD80/86-mediated costimulation provided by APCs.
How Strong Are Strong Interactions

Abstract It is suggested that strong interactions are described by the renormalizable, asymptotically free gauge field theory of colored quarks and gluons and that the renormalized quark-gluon coupling constant is small, when evaluated at momenta of the order of the proton mass. The true asymptotic predictions of this theory for deep inelastic scattering are shown to be irrelevant for present experiments. Scaling is found to be violated logarithmically according to lowest order perturbation theory. Upper bounds for the strong interaction coupling constant are derived.
Bone Marrow Connexin-43 Expression Is Critical for Hematopoietic Regeneration After Chemotherapy

Contact between bone marrow (BM) hematopoietic stem cells (HSC) and osteoblast/stromal (OS) cells has been shown to be crucial in the regulation of hematopoiesis. However, very little is known about the regulatory mechanisms of direct cell-to-cell communication in the hematopoietic microenvironment. Gap junction channels (connexons) are formed by polypeptides (connexins) arranged in hexamers and represent the best described intercellular communication system. Connexin-43 (Cx43) is expressed by BM OS cells and has been associated with the cadherin/beta -catenin signaling pathway, recently reported as relevant in the OS/HSC interaction at the stem cell niche. Here, we employed an inducible gene-targeted murine approach to study the role of Cx43 in HSC proliferation and differentiation in vivo. Mx-Cre/Cx43+/+ and Mx-Cre/Cx43flox/flox littermates have been analyzed after gene deletion induced in vivo by the interferon-inducer poly (I)-poly (C), generating control (Cx43+) and Cx43-deficient (Cx43-/-) mice. After one week, Cx43+ and Cx43-/- mice were treated with 5-fluorouracil (5-FU). Cx43 expression in Cx43-/- BM was markedly reduced (> 90%) as analyzed on day +14 post-5-FU treatment. Cx43 deficiency did not induce a significant change in peripheral blood counts before 5-FU treatment, but the hematopoiesis recovery after 5-FU treatment was severely impaired as demonstrated by absence of recovery of peripheral blood counts, including profound neutropenia, anemia with reticulocytopenia, thrombocytopenia and a 5- to 8-fold decrease of cellularity and hematopoietic progenitor content (granulomacrophagic colony-forming-units (CFU-GM-), erythroid burst forming units (BFU-E) and mixed colony forming units (CFU-mix-) in BM and spleen on day +14 post-5-FU treatment. However, the femoral content of Lin-/c-kit+/Sca1+ cells in Cx43-/- BM was maintained when compared to Cx43+ BM. Short-term competitive repopulation ability of Cx43-/- BM cells was diminished as compared to Cx43+ mice, specifically for myeloid and B lymphoid cells, but showed spared long-term competitive repopulation ability with roughly normal hematopoietic differentiation. These data suggest that hematopoietic regeneration after cycle-specific chemotherapy is blocked in Cx43-deficient mice at the long-term HSC repopulating level. Cx43 expression within the BM appears to be crucial in the development of an efficient response to hematopoietic stress.
Organic chemistry: Amide bonds made in reverse

Amide bonds connect the amino acids in proteins and occur in many other useful molecules. An amide-forming reaction that turns the conventional approach on its head offers a practical way of making these bonds.
Strategic workload management and decision biases in aviation

Thirty pilots flew three simulated landing approaches under conditions of low, medium, and high workload. Workload conditions were created by varying time pressure and external communications requirements. Our interest was in how the pilots strategically managed or adapted to the increasing workload. We independently assessed the pilot's ranking of the priority of different discrete tasks during the approach and landing. Pilots were found to sacrifice some aspects of primary flight control as workload increased. For discrete tasks, increasing workload increased the amount of time in performing the high priority tasks, decreased the time in performing those of lowest priority, and did not affect duration of performance episodes or optimality of scheduling of tasks of any priority level. Individual differences analysis revealed that high-performing subjects scheduled discrete tasks earlier in the flight and shifted more often between different activities.
Celebrating the Life and Thought of Ruy Mauro Marini

The late Brazilian political economist Ruy Mauro Marini considered underdevelop ment the outcome of dependent capitalism in Latin America. He used the idea of "subimperialism" to help illuminate this condition and to highlight one of its conse quences, superexploitation of the workforce (Marini, 1973). Subimperialism, he believed, had two components, one relating to national policy regarding productivity and the workforce and the other to an autonomous expansionist policy: "on the one hand, a medium organic composition on the world scale of national productive appa ratus, and, on the other, the exercise of a relatively autonomous expansionist policy which is not only accompanied by a greater integration in the imperialist productive system but also is maintained under the hegemony exercised by imperialism on an international scale" (Marini, 1978: 34-35). After the 1964 coup in Brazil, the military government launched its offensive against the popular forces while reinforcing a coalition of the ruling classes linking the bourgeoisie and the landowner merchant oligarchy, facilitating investment and the introduction of new technology, and promoting capitalization, especially in the countryside. Its domestic capitalism was, however, incapable of effecting any overall change in the national economy, its national bourgeoisie was insignificant in Brazilian development, and autonomous national development could not occur (Marini, 1969:115). The principal problem was that domestic markets could not absorb the increasing productivity, a contradiction that could be resolved to some degree by expansion into new markets, especially its neighboring countries in South America. Thus, government investment in projects with its neighbors was a means of shaping its subimperialism. Marini differed from others interested in dependency in his explicit emphasis on revolution. He argued that the response of workers to their plight would lead Brazil along a revolutionary course. Solidarity among the exploited classes and the emer gence of a vast political movement would sharpen the contradiction between the bourgeoisie and the landowner-merchant oligarchy, impede foreign investment, and promote autonomous development. Rather than reforms and compromises, he said, what was needed was revolutionary struggle against the subimperialist bourgeoisie and imperialism itself (Marini, 1969: 119-120). Marini joined the editorial board of Latin American Perspectives in 1982 and served 16 years as a participating editor. When I interviewed him in Rio de Janeiro later, he
Various Positions: A Life of Leonard Cohen

Ira B. Nadel, Austin, TX: University of Texas Press, 2007, ISBN-10: 0292717326; ISBN-13: 978-0292717329, 297 pp, $24.95 (paperback) Biographies of popular musicians often mythologize their subjects...
On symmetric long-wave patterns in two-layer flows

Abstract The doubly periodic pattern formation of nonlinear partial differential equations that describe the small-amplitude, long wave, interfacial dynamics of a two-layer fluid flow in a channel for small volumetric-flow rates is investigated. This system consists of a Kuramoto-Sivashinsky type equation governing the evolution of the interfacial deflection coupled to a Poisson equation for the disturbance pressure field. The system has reflectional and translational symmetries in the direction of the flow and transverse to the flow. A local analysis near the mutual bifurcation of a two-dimensional wave and oblique waves yields criteria for different bifurcation scenarios near criticality. A numerical study away from the initial bifurcation reveals that for linearly coupled systems, the patterns appear to be steady for moderate values of the bifurcation parameter. When the equations are coupled nonlinearly, instabilities to the local solutions lead to a low-dimensional chaotic attractor through a period-doubling scenario. Oscillatory solutions, such as an exchange of energy from the two-dimensional wave to oblique modes are also seen, along with a travelling-square pattern that is quasi-periodic.
Evidence for a core gut microbiota in the zebrafish

Experimental analysis of gut microbial communities and their interactions with vertebrate hosts is conducted predominantly in domesticated animals that have been maintained in laboratory facilities for many generations. These animal models are useful for studying coevolved relationships between host and microbiota only if the microbial communities that occur in animals in lab facilities are representative of those that occur in nature. We performed 16S rRNA gene sequence-based comparisons of gut bacterial communities in zebrafish collected recently from their natural habitat and those reared for generations in lab facilities in different geographic locations. Patterns of gut microbiota structure in domesticated zebrafish varied across different lab facilities in correlation with historical connections between those facilities. However, gut microbiota membership in domesticated and recently caught zebrafish was strikingly similar, with a shared core gut microbiota. The zebrafish intestinal habitat therefore selects for specific bacterial taxa despite radical differences in host provenance and domestication status.
Repair of nitrous acid damage to DNA in Escherichia coli

A number of mutant strains of Escherichia coli have been examined for their sensitivity to nitrous acid and in some instances to methylmethanesulfonate. All ung- mutants tested are abnormally sensitive to nitrous acid. Since the ung mutation is phenotypically expressed as a defect in uracil DNA glycosidase, this observation supports the contention that treatment of cells with nitrous acid causes deamination of cytosine to uracil. In addition the observed sentitivity indicates that the ung gene is involved in the repair of uracil in DNA. Studies with other mutants suggest that both exonuclease III and DNA polymerase I of E. coli are involved in the repair of nitrous acid damage in vivo.
The crystal sheaths from bivalve hinge ligaments.

The aragonite crystals in the molluscan bivalve hinge ligament are surrounded by an organic sheath which is distinct from the remainder of the ligament matrix. Methods have been developed to isolate these sheathed crystals from the ligaments ofSpisula solidissima andMercenaria mercenaria employing a papain digestion of the matrix protein. The sheathed crystals fromSpisula have a CaCO3/protein ratio of 11.1 and those fromMercenaria a ratio of 29.6. The sheathed crystals and the empty crystal sheaths have been examined by electron microscopy for structural integrity. The sheath proteins exhibit much smaller proportions of the amino acids glycine and methionine than the hinge ligaments. These are characteristic amino acids of high concentration in the hinge ligaments of both species. The concentrations of acidic and basic amino acids are increased about two fold in the sheaths over those of the ligaments. Otherwise there is little similarity in the amino acid composition of the sheaths in the two species. However, SDS electrophoresis shows the sheaths of both to contain a major protein component with a molecular weight of about 25,000. The sheath protein from theMercenaria ligament contains about 5% carbohydrate and that ofSpisula sheaths less than 1% carbohydrate.
Modulation of Lrp action in Escherichia coli by leucine: Effects on non-specific binding of Lrp to DNA

Lrp is a global regulator of metabolism in Escherichia coli that helps cells respond to changes in environmental conditions. The action of Lrp as a transcriptional activator or repressor is sometimes affected by whether the medium contains exogenous leucine. The abundance of Lrp in cells is relatively high (about 15 microM in monomer), and given the relatively high Lrp binding affinity in vitro for specific binding sites (nanomolar apparent dissociation constants), the expectation is that all binding sites will be saturated with Lrp in vivo. Here we consider the fraction of the total Lrp in cells that is free and the fraction that is bound to DNA. Using minicell-producing strains, we measured the distribution of Lrp between cytoplasm and nucleoid in cells grown under different nutritional conditions and in cells in different phases of growth. In E. coli cells grown in minimal medium to mid-log phase, the ratio of free to DNA-bound Lrp was about 0.67. This ratio decreased about threefold when the cells were grown in minimal medium supplemented with leucine. Our results also confirmed the previous finding that growth rate regulates lrp expression by as much as three to fourfold. Growth rate-regulated lrp expression, along with changes in the extent of non-specific binding, influences the level of free Lrp in vivo over a 16-fold range. We propose that the net effect of these processes is to regulate the relative concentrations of free Lrp hexadecamer and leucine-bound octamer, leading to promoter selection in response to environmental conditions.
Guest Editor's Introduction: Micro's Top Picks from Microarchitecture Conferences

With this special issue, IEEE Micro continues its yearly tradition of showcasing some of the most industry-relevant research presented at the top computer architecture conferences of the previous year.
Public disclosure, private information collection, and short-term trading

Abstract This paper examines how public disclosure affects private inforamtion acquisition activity in a market economy. We analyze a setting where traders with short-term investment horizons are allowed to trade on their private information prior to a public disclosure. We demonstrate in this setting that public disclosure stimulates investment in private information acquisition. This result is shown to have implications for the magnitude of the pre-announcement and announcement price reactions to the disclosure.
The synthesis, characterization, and preliminary biological evaluation of 1-beta-D-arabinofuranosylcytosine-5'-diphosphate-L-1,2-dipalmitin.

Abstract Recently, 1-β- D -arabinofuranosylcytosine-5′-diphosphate- DL -1,2-dipalmitin (VIa) was reported to inhibit the growth of L51784 cells in mice and of human colon carcinoma HCT-15 cells, also in mice. This paper describes the synthesis of a single diastereomer by conversion of 1-β- D -arabinofuranosylcytosine 5′-monophosphate (II) to the nucleoside 5′-phosphomorpholidate (III), followed by reaction with L -α-dipalmitoylphosphatidic acid (IV) to give 1-β- D -arabinofuranosylcytosine-5′-diphosphate- L -1,2-dipalmitin (V) in good yield. The separation of the product is described and its characterization by chromatography, elemental analysis, and spectroscopic methods. The lipophilic nature of V renders it insoluble in aqueous media and a method of sample preparation utilizing sonication techniques is described which provides a clear solution suitable for biological evaluation. In addition, the ability of V to inhibit the in vitro growth of L1210 cells and of mouse myeloma MPC 11 cells is desscribed and compared with 1-β- D -arabinofuranosylcytosine (I) and other lipophilic prodrugs of I.
Primary signet-ring carcinoma of the colon

Three cases of primary signet-ring carcinoma, or linitis plastica, of the colon are described. This rare form of colonic carcinoma possesses certain clinical, pathologic, and biologic characteristics that differ from those of the ordinary colorectal adenocarcinoma. Most importantly, the prognosis is poor, with only very few patients surviving more than one year following diagnosis. Some authors believe that the poor prognosis seen with this tumor may be due largely to a delay in diagnosis. Therefore, awareness of this form of colonic malignancy should be stressed so that early recognition may be made at a stage when curative treatment can still be instituted.
“Do No Harm!” — Seismic petrophysical aspects of time — Lapse monitoring

The steps involved in time-lapse seismic petrophysical modeling are simple; the details, however, are imposing. To predict future reservoir seismic response accurately, one must know the future reservoir conditions that may be encountered, including: changes in fluid saturation; changes in the properties of the fluids themselves; changes in the dry-frame moduli; and changes in the whole-rock response (usually modeled by Gassmann theory).