cssi/SciSciGPT-SciSciNet huggingface dataset:
Reduced order H/sub /spl infin// filter design for discrete time-varying systems

This paper addresses the reduced-order H/sub /spl infin// filter design for linear time varying discrete-time systems in which all measurements are not noise-free. The proposed filter has a generalized Luenberger observer structure and its order can be as low as n-p, where n and p are the order of signal systems and the number of measurements, respectively. Several bounded real lemmas are developed and they are the only tools used to establish the reduced-order filter design in this paper.
Propylene Epoxidation over gold-titania catalysts

We present here kinetic isotope effect support for a hydroperoxy—intermediate, data that suggest consideration of oxidized Au in the active site, and XPS evidence for extended TiO2 as sites for propylene oxide oligomerization in the direct epoxidation of propylene to propylene oxide over Au/TiO2 catalysts in H2/O2 mixtures.
PHOSPHATE ABSORPTION IN EELGRASS1

The absorption of phosphate by eelgrass (Zostera marina L.) was studied using 32P in a partitioned container where leaves were separated from roots and rhizomes. Absorption, which was greatest in the light, occurred through both leaves and roots, and the absorbed phosphorus was transported rapidly to all parts of the plant. It therefore appears that eelgrass can use phosphate from sediments and from water. Phosphate removed from solution by the roots and rhizomes was returned in part to the surrounding water through the leaves, suggesting that in nature seagrass may act either as a sink or as a source for dissolved phosphorus in estuarine waters.
A Study of the Sulfhydryl Groups of the Catalytic Subunit of Escherichia coli Aspartate Transcarbamylase THE USE OF ENZYME-5-THIO-2-NITROBENZOATE MIXED DISULFIDES AS INTERMEDIATES IN MODIFYING ENZYME SULFHYDRYL GROUPS

Abstract Each of the three polypeptide chains of the catalytic subunit (CSU) of aspartate transcarbamylase from Escherichia coli has a single —SH group and no disulfides. Although the —SH group is unreactive toward several S-alkylating agents and symmetrical disulfides, it reacts slowly with 5,5'-dithio-bis(2-nitrobenzoate) (DTNB) and p-hydroxymercuribenzoate. CSU is inactivated by these reagents and also, transiently, by inorganic polysulfides. Kinetic studies of the reaction with DTNB show (a) that DTNB does not bind to CSU as a prerequisite for reaction, (b) that reaction depends on the ionization of a group on the enzyme with apparent pKa = 7.9, probably the —SH group, and (c) that inhibitors of enzymatic activity also inhibit reaction of the —SH group with both DTNB and p-hydroxymercuribenzoate. Dissociation constants for phosphate and succinate determined from inhibition of the DTNB reaction agree with those previously determined by steady state kinetics and ultraviolet difference spectroscopy. Undissociated native aspartate transcarbamylase does not react with DTNB under conditions which lead to complete reaction of CSU. Treatment of the CSU-thionitrobenzoate mixed disulfide with nucleophiles such as cyanide, sulfite, and 2-mercapto-ethanol leads to new S- derivatives of CSU. The S-cyano derivative is fully active, but the S-sulfo and S-2-mercapto-ethanol derivatives have little or no activity. We conclude that the —SH group of CSU is very near the active site but is not required for catalytic activity and discuss possible alternative functions for this group. We also discuss the general use of enzyme-thionitro-benzoate mixed disulfides as intermediates in the preparation of specific derivatives of enzyme —SH groups and the potential use of enzyme thiocyanates, prepared through the thionitrobenzoate disulfides, in specific chemical cleavage of polypeptide chains at cysteine and cystine residues.
Capacity investigation of brine-bearing sands of the Fwwm formation for geologic sequestration of CO{sub 2}

The capacity of fluvial brine-bearing formations to sequester CO{sub 2} is investigated using numerical simulations of CO{sub 2} injection and storage. Capacity is defined as the volume fraction of the subsurface available for CO{sub 2} storage and is conceptualized as a product of factors that account for two-phase flow and transport processes, formation geometry, formation heterogeneity, and formation porosity. The space and time domains used to define capacity must be chosen with care to obtain meaningful results, especially when comparing different authors' work. Physical factors that impact capacity include permeability anisotropy and relative permeability to CO{sub 2}, brine/CO{sub 2} density and viscosity ratios, the shape of the trapping structure, formation porosity and the presence of low-permeability layering.
Frequency evolution of neutron peaks below T c : Commensurate and incommensurate structure in La 0.85 Sr 0.15 CuO 4 and YBa 2 Cu 3 O 6.6

We study the evolution of the neutron cross-section with variable frequency $\omega$ and fixed $T$ below $T_c$ in two different cuprate families. Our calculations, which predominantly probe the role of d-wave pairing, lead to generic features, independent of Fermi surface shapes. Among our findings, reasonably consistent with experiment, are (i) for $\omega $ near the gap energy $\Delta$, both optimal {LaSrCuO} and slightly underdoped YBCO exhibit (comparably) incommensurate peaks (ii) peak sharpening below $T_c$ is seen in {LaSrCuO}, (iii) quite generically, a frequency evolution from incommensurate to commensurate and then back to incommensurate structure is found with increasing $\omega$. Due to their narrow $\omega$ regime of stability, commensurate peaks in {LaSrCuO} should be extremely difficult to observe.
An adaptive fuzzy logic controller for poly-tree structured workcell layouts

A methodology for solving the workcell layout problem is investigated by using an adaptive fuzzy logic controller to assign distance. Relationships within the workcell layout are assumed to be in a poly-tree structure. The desired distance between two pieces of equipment are represented by fuzzy linguistic variables. A heuristic-geometric procedure is applied to fit the workcell layout structure within a workspace. This provides a new workcell layout scheme which permits solution when the design requirements for the layout are in inexact and in vague form, which is typical in preliminary design.
On solving boundary value problems of modified Helmholtz equations by plane wave functions

Plane wave functions eλ〈x, wθ〉 in R2, where λ > 0, x = (x, y), wθ = (cos θ, sin θ), and 〈x, wθ〉 := x cos θ + y sin θ, are used as basis functions to solve boundary value problems of modified Helmholtz equations Δu(x) - λ2u(x) = 0, x ∈ Ω, u(x)= h(x) x ∈ ∂Ω, where Δ is the Laplace operator and Ω a bounded and simply connected domain in R2. Approximations of the exact solution of the above problem by plane wave functions are explicitly constructed for the case that Ω is a disc, and the order of approximations is derived. A computational algorithm by collocation methods based on a simple singular decomposition of circular matrices is proposed, and numerical examples are shown to demonstrate the efficiency of the methods.
The Application of the Saturated-Core Reactor and Regulator

The purpose of this paper is to state briefly the use of voltage regulators and reactors in transmission and distribution systems and to mention operating requirements which might be best met by the use of saturated-core type regulators or reactors. The saturated-core type regulator and reactor consists of an iron core with two sets of coils. One set of coils is connected to a d-c. circuit and the other set to an a-c. circuit. The theory, design and construction of the saturated-core type regulator and reactor is discussed in A. Boyajian's paper.
Using a model railroad to teach digital process control

This paper describes experiences with a course designed to introduce undergraduate students to the design and implementation of real-time systems for the monitoring and control of laboratory and industrial processes. A model railroad is suggested as an inexpensive process to control. A variety of laboratory exercises involving such a model railroad are presented.
Adding propositional connectives to countable infinitary logic

For countable admissible α, one can add a new infinitary propositional connective to so that the extended language obeys the Barwise compactness theorem, and the set of valid sentences is complete α-r.e. Aside from obeying the compactness theorem and a completeness theorem, ordinary finitary predicate calculus is also truth-functionally complete. In (1), Barwise shows that for countable admissible A , provides a fragment of which obeys a compactness theorem and a completeness theorem. However, we of course lose truth-functional completeness, with respect to infinitary propositional connectives that operate on infinite sequences of propositional variables. This raises the question of studying extensions of the language obtained by adding infinitary propositional connectives, in connexion with the Barwise compactness and completeness theorems, and other metatheorems, proved for Some aspects of this project are proposed in (3). It is the purpose of this paper to answer a few of the more basic questions which arise in this connexion. We have not attempted to study the preservation of interpolation or implicit definability. This could be quite interesting if done systematically.
Solute Concentration Gradients in Frog Muscles at 0°C: Active Transport or Adsorption?

In isolated frog muscle that has been incubated for 7 days at 0°C invitro K+ and Na+ remain at normal concentrations. Amino acids are accumulated against a concentration gradient at this temperature; for example, glycine accumulates in muscle to a concentration ten times that in the external solution. The amount of cycloleucine accumulated is greater at 0°C than at 25°C. These findings, which are difficult to explain on the basis of metabolically linked active transport, are Consiststent with the view that solute accumulation by cell is the result of adsorption on spesific sites.
Metabolic fuel homeostasis in syrian hamsters: nycthemeral and exercise variables

The food intake and growth of male and female golden hamsters, with and without access to running wheels, were measured under several conditions. These included different seasons, photoperiods and diets. Chow-fed males in wheels invariably had slowed weight gain and showed little hyperphagia relative to sedentary controls. One group of exercising female hamsters, fed high fat diet, grew faster than sedentary controls. The food intake of both exercising and sedentary groups was distributed evenly through the day/night cycle, but the exercising animals took smaller, more frequent meals at night. The nycthemeral variations in plasma glucose, triglycerides, free fatty acids and liver glycogen were quite small in sedentary hamsters. In exercising hamsters, however, liver glycogen was elevated in the late daytime and depleted in the mid-to-late night. In vivo lipogenesis rates in white and brown adipose and liver were elevated by day in the exercising compared to sedentary hamsters, and were lower at night in both groups. It appears that in exercising hamsters, and to a lesser extent sedentary hamsters, the day phase is one of inactivity and fuel storage, and the night phase is one of exercise and fuel mobilization.
Monte Carlo Predictions of Prompt Fission Neutrons and Photons: a Code Comparison

Abstract This paper reports on initial comparisons between the LANL CGMF and LBNL/LLNL FREYA codes, which both aim at computing prompt fission neutrons and gammas. While the methodologies used in both codes are somewhat similar, the detailed implementations and physical assumptions are different. We are investigating how some of these differences impact predictions.
Controllability and stabilizability of vibrating simply supported plate with pointwise control

Semigroup extension approach is taken to formulate the vibration of a simply supported rectangular plate on @W = [0, a] x [0, b] with pointwise controllers as an abstract controlled evolutionary system. Via spectrum analysis by means of related Diophantine equations and theorems in number theory, an alternative principle is proved in this paper: (I) If a^2b^2 is rational, then the system is neither approximately controllable nor weakly stabilizable with pointwise controllers; (II) if a^2b^2 is irrational, then a single pointwise controller located at any fixed point (p, q) @e @W^0 with pa and qb both irrational can make the system approximately controllable and strongly stabilizable.
Functional interaction between leaf trichomes, leaf wettability and the optical properties of water droplets

Abstract. Because CO2 diffuses 10000 times more slowly through water than air, there may be strong selective pressure for increased water repellency in terrestrial plant leaves. In the present study, leaf trichomes appeared to have a strong influence on leaf water repellency (i.e. degree of water droplet formation on the leaf surface) as well as the retention of droplets on the leaf. Based upon evaluation of 38 plant species from 21 families, we found that leaves with trichomes were more water repellent, especially where trichome density was greater than 25mm2. However, droplet repellency and retention were both high in some species where trichomes entrapped droplets. Finally, the lensing effects of water droplets on leaf surfaces increased incident sunlight by over 20-fold directly beneath individual droplets. These results may have important implications for such processes as stomatal function, whole leaf photosynthesis, and transpiration for a large variety of plant species.
5MinuteConsult: Clinical Decision Support

5MinuteConsult: Clinical Decision Support software is primarily designed for physicians. It contains information on 2,000 diseases and conditions in 21 medical specialties in primary care. It is designed to be a point-of-care tool for physicians; however, it also includes supplemental information such as ICD-9 codes, images, clinical procedures videos, physical therapy videos, and patient handouts.
A glossary of chigger terminology (Acari: Trombiculidae).

The terms and abbreviations used in the descriptions of larval trombiculid mites are defined and selectively illustrated.
C-type inactivation of a voltage-gated K+ channel occurs by a cooperative mechanism

The lymphocyte voltage-gated K+ channel, Kv1.3, inactivates by a C-type process. We have elucidated the molecular basis for this process using a kinetic analysis of wild-type and mutant (A413V) Kv1.3 homo- and heteromultimeric currents in a mammalian lymphoid expression system. The medians of the measured inactivation time constants for wild-type and A413V homotetrameric currents are 204 and 4 ms, respectively. Co-expression of these subunits produces heteromultimeric channels manifesting inactivation kinetics intermediate between those of wild-type and A413V homomultimers. We have considered several models in which each subunit acts either independently or cooperatively to produce the observed inactivation kinetics. The cooperative model gives excellent fits to the data for any heteromultimeric composition of subunits, clearly distinguishing it from the independent models. In the cooperative model, the difference in free energy between the open and inactivated states of the channel is invariant with subunit composition and equals approximately 1.5 kcal/mol. Each subunit contributes equally to the activation free energy for transitions between open and inactivated states, with an A413V subunit decreasing the free energy barrier for inactivation (and for recovery from inactivation) by approximately 0.6 kcal/mol. Our results are consistent with a physical model in which the outer mouth of the channel constricts during C-type inactivation (G. Yellen, D. Sodickson, T. Chen, and M.E. Jurman, 1994, Biophys. J. 66:1068–1075).
The linear amino acid sequence α1 acid glycoprotein

Es gelang, die lineare Aminosauresequenz von saurem α1-Glykoprotein (Orosomucoid), einem Globulin des menschlichen Plasmas, aufzuklaren.
SPECTROSCOPIC ANALYSIS OF ELECTRICALLY POLARIZED POLYACRYLONITRILE.

Abstract : Electrically polarized and unpolarized films of poly(Acrylonitrile) have been investigated by both infrared attenuated total reflection (ATR) and thermally stimulated discharge (TSD). ATR analysis of PAN films has been aimed at explaining the molecular origin of thermally stimulated currents, and consequently that of phenomena contributing to electrical polarization in this material. Preferred orientation of nitrile dipoles along the thickness direction (applied electric field direction) has been detected by ATR in both polarized and unpolarized films. It is suggested that dipolar alignment in unpolarized solvent cast films results from internal electric fields associated with space charges. The observed orientational anisotropy is found to disappear gradually as films (both polarized and unpolarized) are heated from ambient temperature to 100 C and rotational motion in the backbone is thermally activated. tsd currents observed in this thermal range are thus associated with randomization of molecular dipoles. TSD currents observed above 100 C are suggested to originate from drift of space charges, since both an isotropic orientation of dipoles and onset of considerable diffusion are detected by ATR in this temperature range.
Multimodality imaging of aortic valve fibroelastoma.

A 66-year-old hypertensive female with occasional palpitations and non-specific ECG changes underwent screening transthoracic echocardiogram which revealed a 1.0 × 0.7 cm, mobile, echogenic mass attached to the left aortic valve cusp ( Panel A , Supplementary data online, Video S1 ). Subsequent transoesophageal echocardiogram confirmed the presence and anatomical location of the mass ( Panels B and C …
Replacing Teacher Talk with Gestures: Nonverbal Communication in the Foreign Language Classroom

ABSTRACT Studies on nonverbal communication in the classroom have generally focused on the elementary school and on teaching methods which may be employed in teaching any subject matter. Researchers have paid little attention to the unique situation in language classes. Yet foreign language teachers who consciously control their movements and stance enjoy a subtle but effective power. During pattern drills, they can increase noticeably the tempo of the class, while concurrently reducing teacher talk. Throughout a class period encompassing such varied activities as conversation and choral repetition, language teachers can use gestures to signal and instigate changes in the class atmosphere and thus further their instructional goals. Moreover, through nonverbal communication, they can effect personalization between class members and thus lessen the inhibitions which normally plague language students. For teachers who wish to analyze and improve their own use of gesture and nonverbal communication in the classroom, it is suggested that a videotape recording of the class provides useful and objective feedback.
The relation between capillaries and neurons in the caudal neurosecretory system ofPomatomus saltatrix

The caudal neurosecretory system ofPomatomus saltatrix was examined. Particular interest was devoted to the perikarya of the neurosecretory cells. The majority of these cells were characterized by a close association with the capillary network. The cells appeared to ensheath the capillaries thus bringing the nucleus and perinuclear cytoplasm into close association with the capillaries.
Structure of poly 8-bromoadenylic acid: conformational studies by CPF energy calculations

Poly 8-bromoadenylic acid [poly(BBrA)] is the only known all-syn polynucleotide. It shows a helix-coil transition with a melting curve centred around 55 degrees C. Energy calculations based on classical potential functions have been used to explore the three-dimensional structure of this polymer in helix and random coil. It is concluded that the ordered state is a helix of two parallel strands with a two-fold rotation axis, and the duplex is stabilised by hydrogen bonds involving N1 and H6. Each strand has a conformation with C3' endo geometry, phi' = 216 degrees, omega' = 280 degrees, omega = 294 degrees, phi = 179 degrees, chi = 243 degrees and psi = 57 degrees. Such a conformation leads to approximately 8 nucleotide units per turn of the helix and an axial rise of 3.9A degrees. The structure of poly(8BrA) has been compared with that of the related polymer poly(A) which forms a double helical structure in acidic conditions with bases in the anti conformation and with interstrand hydrogen-bonds between N7 and H6. This is the first time that a specific geometrical model of a novel polynucleotide structure has been produced initially by potential energy calculations, though such calculations on a number of known structures have been reported previously.
EM plane‐wave diffraction by a material‐coated perfectly conducting half‐plane‐ oblique incidence

A high-frequency solution is developed for the electromagnetic diffraction of an obliquely incident plane wave by a material-coated perfectly conducting half-plane. It is assumed that the coating is electrically thin so that it can be modeled by a generalized impedance boundary condition of O(t), where t is the coating's thickness. © 1994 John Wiley & Sons, Inc.
Adult vs. adolescent rats differ in biobehavioral responses to chronic nicotine administration.

Abstract More than 90% of smokers begin smoking during adolescence, suggesting that nicotine's actions may differ in adults vs. adolescents in ways that render adolescents vulnerable to smoking initiation. This experiment tested the hypothesis that nicotine's biobehavioral actions differ in adult and adolescent rats. Forty-two male (21 adolescents, 21 adults) and 41 female (21 adolescents, 20 adults) Sprague–Dawley rats were administered saline or 12 mg/kg/day nicotine via osmotic minipump for 21 days. Body weight, feeding, and locomotion (horizontal activity, vertical activity, center time) were measured before, during, and after saline or nicotine administration. Nicotine's effects depended on age and sex. Nicotine reduced body weight and feeding of adult males and females, and of adolescent males, but not of adolescent females. In addition, adolescent males were more sensitive than adults or adolescent females to nicotine's activity-enhancing effects. In cessation, nicotine-exposed adolescent males continued to exhibit greater activity than saline-exposed animals. Results indicate that nicotine's biobehavioral actions differ depending on age and sex.
Origin of Tuffs in Stanley Group, Ouachita Mountains, Arkansas and Oklahoma: ABSTRACT

Five major tuff sequences (8-120 ft thick) are interbedded with marine graywacke and shale in the 11,000 ft-thick Mississippian Stanley Group. They are present in the basal 1,500 ft and upper 350 ft of the highly folded flysch group. These widespread sequences are thickest and best exposed in the southern Ouachitas, but are traceable to the central Ouachitas. End_Page 355------------------------------ Three tuff sequences are composed of massive and bedded crystal tuff; 2 are composed of massive and bedded pumiceous vitric-crystal tuff. All five sequences have massive and sometimes laminated fine-grained vitric upper portions. Crystal-rich and pumiceous tuff sequences probably reflect different settling and/or eruptive histories. Crystal tuff sequences originated from crystal-rich magmas or from crystal enrichment by gravity sorting of pyroclastic debris settling through long water columns, possibly as a result of vulcanian-type submarine eruptions. Bedded crystal tuff was deposited from a series of ash falls and tuffaceous turbidites. Widespread slumping of bedded crystal tuff produced massive crystal tuff. Pumiceous tuff sequences probably formed from Katmai-like eruptions. Thick, nonwelded pumiceous vitric-crystal tuffs commonly overlain by thin-bedded pumiceous tuffs were produced from submarine pyroclastic flows covered by contemporaneous ash falls. Fine-grained vitric tuff formed from slow settling of very fine ash. The ash was possibly the finest size remnants suspended in settling columns after major eruptions and/or was produced by weaker ash falls. Rare cross bedding is evidence for some current reworking. Tuff thickness, grain-size trends, paleocurrent indicators, and paleogeography suggest a southern volcanic source, possibly the buried Luling overthrust front in Texas. End_of_Article - Last_Page 356------------
Getting the Message Out

In a recent issue of Molecular Cell, Schwer (2008) demonstrates that, during the latest stage of the splicing reaction, the RNA-dependent helicase Prp22 is deposited upon the downstream exon, where it subsequently strips the spliced messenger RNA from the spliceosome.
Coeliac disease. IV. An investigation into the injurious constituents of wheat in connection with their action on patients with coeliac disease.

Summary Based on the results of an investigation of a number of patients with coeliac disease, the harmful action of wheat flour was shown to be chiefly inherent to the gliadin fraction.
Endoscopic approaches to treatment of achalasia

Endoscopic therapy for achalasia is directed at disrupting or weakening the lower esophageal sphincter (LES). The two most commonly utilized endoscopic interventions are large balloon pneumatic dilation (PD) and botulinum toxin injection (BTI). These interventions have been extensively scrutinized and compared with each other as well as with surgical disruption (myotomy) of the LES. PD is generally more effective in improving dysphagia in achalasia than BTI, with the latter reserved for infirm older people, and PD may approach treatment results attained with myotomy. However, PD may need to be repeated. Small balloon dilation and endoscopic stent placement for achalasia have only been used in select centers. Per oral endoscopic myotomy is a newer endoscopic modality that will likely change the treatment paradigm for achalasia. It arose from the field of natural orifice transluminal endoscopic surgery and represents a scarless endoscopic approach to Heller myotomy. This is a technique that requires extensive training and preparation and thus there should be rigorous accreditation and monitoring of outcomes to ensure safety and efficacy.
Intracellular targets of cyclosporine

Since cyclosporine was first reported to improve psoriasis, investigators have been trying to determine its mechanism of action. In addition to the well-documented effects on cytokine production by T lymphocytes, a direct effect on keratinocytes has been proposed. Cyclophilin and calmodulin, two proteins that are present in both lymphocytes and keratinocytes, have been considered as possible intracellular targets for cyclosporine. Cyclophilin binds cyclosporine with high affinity and the ability to bind cyclophilin correlates with the immunosuppressive effects of cyclosporine analogs. Cyclophilin is identical to peptidyl-prolyl cis-trans isomerase, an enzyme that catalyzes refolding of proteins. The process of protein folding may be important in DNA-protein and protein-protein interactions. Calmodulin is an intracellular calcium-binding protein that is important in the regulation of cell proliferation. Cyclosporine binds to calmodulin with low affinity, and such binding of cyclosporine isomers does not reflect their immunosuppressive activity. The physiologic importance of calmodulin-to-cyclosporine binding is controversial.
Some Pharmacological Properties of Tricyclamol, a New Anticholinergic Agent

The results of quantitative determinations of sweat and saliva before and after drug or placebo administration are reported. The effects of prolonged administration and manifestations of parasympathetic inhibition with the drug in normal and hidrose subjects are also reported. Measurement of locomotor activity in rats to ascertain the central effects of tricyclamol is discussed.
Total cholesterol and HDL-cholesterol changes during acute, moderate-intensity exercise in men and women

Chronic endurance exercise training has been associated with decreased levels of total cholesterol and increased HDL-cholesterol. To our knowledge rapid changes in cholesterol and HDL-cholesterol during acute exercise have not been described under controlled conditions. We studied 28 subjects (14 males and 14 females) during bicycle exercise for 40 min at a work intensity of 55% of their maximal oxygen consumption. Total and HDL-cholesterol levels were measured (and LDL-cholesterol calculated) at rest, 10, 20, 30, and 40 min of exercise, and 15 min postexercise. There was a significant (p less than 0.001) increase in HDL-cholesterol levels at 10 min of exercise (58.8 +/- 13.9 mg/dl, mean +/- SD) above rest (53.1 +/- 13.4 mg/dl) for all subjects. This increase persisted (p less than 0.001) at all time points throughout the exercise session, but declined by 15 min postexercise. There was a small, insignificant decline in LDL-cholesterol. It is concluded that apparent favorable changes in lipoprotein patterns occur acutely, and are sustained during short-term, moderate intensity exercise. Analyses of these changes appears necessary if the biochemical mechanisms which underlie these metabolic alterations are to be elucidated.
Poly(ADP-Ribose) Inhibition: Exploring a New Approach to Breast Cancer Prevention in BRCA1/2 Mutation Carriers

Carriers of deleterious BRCA1 and BRCA2 mutations face an elevated risk of developing breast cancer. This risk warrants consideration of prevention interventions. Currently, the only proven prevention intervention for BRCA mutation carriers is risk-reducing surgery. Inhibitors of poly(ADP-ribose) polymerase (PARP) are a new class of drugs that appear to be effective in treating BRCA mutation–associated cancers and triple-negative breast cancers. PARP inhibitors may offer a new approach to breast cancer prevention in BRCA mutation carriers. This article reviews current breast cancer prevention interventions for BRCA mutation carriers and discusses the rationale for investigating new chemoprevention agents in this population. The mechanism of action of PARP inhibitors and the rationale for studying them in BRCA mutation carriers is reviewed. Published clinical trials regarding PARP inhibitors and ongoing research regarding PARP inhibitors and breast cancer prevention are reviewed.
Highly purified neurophysin proteins: Method of isolation based on their acidic properties

Abstract The isolation of highly purified bovine neurophysins I and II from freshly frozen posterior pituitaries is reported. The method can also be used for the isolation of neurophysins from other species, and acetone-desiccated preparations may serve as starting material as well. Crude posterior pituitary extract was obtained as described by Hollenberg and Hope (1967, Biochem. J., 104, 122–127). Basic and neutral proteins were then separated from the acidic neurophysins by cation-exchange chromatography on Cellex-CM (carboxymethyl). Neurophysin I was separated from neurophysin II by anion-exchange chromatography on DEAE-(diethylaminoethyl)-Sephadex with a continuous sodium chloride gradient (0 to 0.4 m ). Highly purified bovine neurophysin I was also secured with a stepwise sodium chloride gradient (0.22 m starting gradient followed by a steep gradient from 0.22 to 0.4 m ). The current method yields neurophysin proteins in a higher overall yield than previous procedures, as determined by single radial immunodiffusion and concentration-dependent absorption after disc electrophoresis. The method also gives neurophysins of greater purity than standard procedures currently in use. The proteins are characterized by a single, sharp precipitation band on immunodiffusion and immunoelectrophoretic analysis against antiporcine neurophysin antibody, by single bands on analytical gel disc electrophoresis at a running pH of either 8.8, 5.9, or 4.0. Isoelectric focusing on polyacrylamide gel gave an apparent pI value of 4.31 ± 0.07 for neurophysin I and a value of 4.79 ± 0.11 for neurophysin II. Radioimmunoassay revealed barely detectable levels of adrenocorticotropin-like material in neurophysin I (12 pg/100 μg of neurophysin) and no detectable levels in neurophysin II. Both proteins were devoid of avian vasodepressor activity in the conscious chicken, melanotropic activity in vitro in frog skin, and did not effect electrolyte excretion in hydropenic rats.
Genetic Diversity among Elite Sorghum Inbred Lines Assessed with Simple Sequence Repeats

DNA markers are being increasingly utilized in cultivar development, quality control of seed production, measurement of genetic diversity for conservation management, varietal identity, and to assist in maintenance of intellectual property protection (IPP). The use of simple sequence repeats (SSRs) for variety profiling can provide high discrimination, with excellent reproducibility at less cost than for restriction fragment length polymorphisms (RFLPs). The objective of this study was to evaluate the potential utility of SSR technology for applications in research, product development, seed production, and genetic resource conservation management for sorghum. Fifty genetically diverse elite sorghum [Sorghum bicolor (L.) Moench] inbreds were used to compare the discrimination abilities of 15 SSR primers with 104 RFLPs and to compare the associations among lines revealed by these molecular data and by pedigrees. RFLP data allowed all lines to be uniquely identified; two lines could not be distinguished by the SSR data. The mean polymorphism information content (PIC) values were 0.62 (RFLPs) and 0.58 (SSRs). Correlations for pairwise molecular profile distances with pedigree distances among the maintainer female (B) lines were 0.52 and 0.53 for RFLP and SSR data, respectively; data for the male parental restorer (R) lines were 0.41 and 0.47. This set of SSRs could be used to help genetic conservation management and to support IPP. Data from additional SSRs that collectively cover more of the genome will be required for applications to assist in breeding.
Correlation in ultrastructural cryoinjury of mitochondria with aspects of their respiratory function.

Abstract Mitochondria in cells of the renal cortex were studied as to comparative cryoinjury induced by methods of freezing and thawing considered to cause slight and extensive damage. Functional integrity of mitochondria was measured in terms of rate of oxygen consumption of tissue slices (QO2), respiratory control ratio and cytochrome oxidase activity. Ultrastructural manifestation of cryoinjury included change in shape, swelling, precipitation and loss of matrix, loss of dense granules, and irregularity and loss of cristae. Results of structure-function evaluation indicated that: (1) Freezing and thawing under conditions described uncoupled mitochondria; (2) mtochondrial physical damage was greater in slices frozen rapidly and thawed slowly than in those slowly frozen and rapidly thawed, as predicted; (3) values for QO2, respiratory control ratio and cytochrome oxidase activity correlated fairly well with this difference in cryoinjury; (4) per cent survival values of QO2 for slow freeze, rapid thaw, and for rapid freeze, slow thaw, respectively, were 20% and 10%; 54% and 43% for respiratory control ratio; and 80% and 53% for cytochrome oxidase activity. This showed greatest damage to tissue QO2 and suggested injury to extramitochondrial factors in respiration as well as to mitochondria.
Activity and stability of immobilized carbonic anhydrase for promoting CO2 absorption into a carbonate solution for post-combustion CO2 capture

An Integrated Vacuum Carbonate Absorption Process (IVCAP) currently under development could significantly reduce the energy consumed when capturing CO2 from the flue gases of coal-fired power plants. The biocatalyst carbonic anhydrase (CA) has been found to effectively promote the absorption of CO2 into the potassium carbonate solution that would be used in the IVCAP. Two CA enzymes were immobilized onto three selected support materials having different pore structures. The thermal stability of the immobilized CA enzymes was significantly greater than their free counterparts. For example, the immobilized enzymes retained at least 60% of their initial activities after 90 days at 50 °C compared to about 30% for their free counterparts under the same conditions. The immobilized CA also had significantly improved resistance to concentrations of sulfate (0.4 M), nitrate (0.05 M) and chloride (0.3 M) typically found in flue gas scrubbing liquids than their free counterparts.
Lyapunov-based adaptive state estimation for a class of continuous-time nonlinear stochastic systems

This paper is concerned with an adaptive state estimation problem for a class of continuous-time nonlinear stochastic systems with unknown constant parameters. These nonlinear systems have a linear-in-parameter (affine) structure and the nonlinearity is assumed to be bounded in a Lipschitz-like manner. Using stochastic counterparts of Lyapunov stability theory, we present adaptive state and parameter estimators with ultimately exponentially bounded estimator errors in the sense of mean square. Sufficient conditions are given in terms of the solvability of LMIs. In addition, we introduce a suboptimal design approach. By a martingale method, we demonstrate that this suboptimal design procedure also minimizes an upper bound of estimation error in almost sure sense.
A risk-adjusted definition of biochemical recurrence after radical prostatectomy

To determine whether a variable definition of biochemical recurrence (BCR) based on clincopathologic features facilitates early identification of patients likely to suffer from disease progression. The definition of BCR after radical prostatectomy (RP) bears important implications for patient counseling and management; however, there remains a significant debate regarding the appropriate definition. The study cohort consisted of 3619 men who underwent RP for localized prostate cancer from 1989 to 2007, with data abstracted from the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) registry. Patients were stratified into three risk groups according to Cancer of the Prostate Risk Assessment post-Surgical (CAPRA-S) score. Three single threshold PSA cut-points for BCR were evaluated (PSA⩾0.05, ⩾0.2 and ⩾0.4 ng ml−1) as well as a variable cut-point defined by risk group. After reaching the cut-points, patients were followed for further PSA progression. The proportion of patients with BCR differed by cut-point and risk group, ranging from 7 to 37% (low risk), 22 to 58% (intermediate risk) and 60 to 86% (high risk). The positive-predictive value (PPV) for predicting further PSA progression was 49% for the PSA⩾0.05 ng ml−1, 62% for the PSA⩾0.2 ng ml−1, 65% for the PSA⩾0.4 ng ml−1 and 68% for the risk-adjusted definition. Five-year progression-free survival was 39% for the risk-adjusted definition compared with 45–52% for the other definitions of BCR. These data suggest that a variable definition of BCR determined by clinicopathologic risk may improve the identification of early recurrence after RP without increasing the overdiagnosis of BCR. By using a risk-adjusted BCR definition, clinicians can better predict future PSA progression and more appropriately counsel patients regarding salvage therapies.
Influence of stream vorticity on friction and heat exchange in application to the case of a supersonic jet impinging on an obstacle

The flow in the neighborhood of the stagnation point of a stationary plane stream of viscous incompressible fluid with harmonic components superposed on the velocity components is investigated. Such a flow corresponds to a stream containing periodic eddies perpendicular to the flow plane. The results of the investigation can be applied to estimate thermal fluxes.
Kinetic models for the autocatalytic deprotection of copolymers based on 4‐hydroxystyrene and styrene

Poly(tert-butylcarbonyloxystyrene) by itself or as a component in a copolymer decomposes at elevated temperatures (about 130–150°C) to give the free phenolic group, isobutylene, and carbon dioxide. It has been found that the isothermal conversion of the ester (the protected phenol) to the free phenol proceeds slowly at first but accelerates with time so that the rate of reaction increases until more than half the reaction is over. Thus, the pattern of conversion with time is typical of an autocatalytic process. Although the classical model of autocatalysis which we reported earlier gave a qualitative representation of the process, two modifications to the model result in a much better approximation to the actual experimental data. These two experimentally rational modifications take into account the very real decrease in the volume of the reacting system as conversion (deprotection) proceeds and the possibility that the catalyzed (fast) reaction is second order in free phenol. © 1996 John Wiley & Sons, Inc.
Resonant-cavity-enhanced GaAsSb avalanche photodiodes with separate absorption, charge and multiplication regions operating at 1300nm

Avalanche photodiodes (APDs) with high speed, high quantum efficiency, low dark current and low multiplication noise are very important in long-haul, high-bit-rate fiber optic communication systems. Operation at the telecommunication wavelength of 1.3|im is a useful attribute. Traditionally, InP-based materials such as InGaAsP have been utilized at this wavelength. However, there are drawbacks for InP-based devices as compared to those fabricated on GaAs substrates. For example, InP wafers are much more expensive than GaAs. In addition, devices on GaAs substrates will benefit from their compatibility with the more advanced GaAs-based electronic technology. Since there are no naturally available material systems lattice-matched on GaAs that can absorb light at 1.3|J.m, in recent years, significant efforts have been devoted to achieve 1.3μm absorption on GaAs substrates. The approaches include InGaNAs alloys, (Ga)InAs quantum dots (QDs) and wafer bonding between GaAs substrates and InGaAsP active layers. An alternative choice is GaAsSb alloy grown on GaAs substrate with high compressive strain. The easy incorporation of an arbitrary amount of Sb into GaAs makes GaAsSb a promising material system. We have reported a GaAsSb resonant-cavity-enhanced (RCE) p-i-n photodiode operating at 1.3μm with 54% external quantum efficiency but high dark current near breakdown [1]. It is known that the separation of absorption and highfield multiplication regions by a thin uniformly doped charge layer, the SACM structure, can significantly lower down the dark current [2]. It has also been reported that a thin AlxGa1−xAs multiplication region with high Al concentration (x>0.8) can result in very low multiplication noise [3]. To date, however, this type of very low noise multiplication region has not been incorporated into a SACM APD. In this paper, we demonstrate a RCE GaAsSb SACM APD that exhibited much lower dark current than the p-i-n structure and also very low multiplication noise.
Respiration, growth and viability of repair-deficient mutants of Escherichia coli after ultraviolet irradiation.

SummaryEscherichia coli WP2 (a tryptophan-requiring strain of B/r) and three mutants deficient in DNA repair processes were used for a comparative study of the effects of ultraviolet radiations on respiration. An hcr− strain behaved similarly to WP2 hcr+; respiration ceased about an hour after U.V. The doses used for stopping respiration were 55 and 520 erg/mm2 respectively; these doses reduced survival in each case to about 0·5 per cent. WP2 rec− (Rec A) and WP2 exr− strains did not cease respiring after receiving a range of doses up to 520 ergs/mm2. Following irradiation, WP2 hcr+ and WP2 hcr− cells degraded their DNA slightly if at all, but degradation was extensive in the rec− and exr− strains at doses that reduced survival to 1·0 per cent (33 and 150 ergs/mm2 respectively). We conclude that cessation of respiration of irradiated Escherichia coli is dependent on the integrity of their DNA and not on the radiation sensitivity.
Controlling Preferences for Lotteries on Units of Experimental Exchange

In an experimental setting when outcomes are stochastically related to actions, predictions of equilibrium behavior depend not only on the participants' preference orderings of outcomes, but also on their orderings of lotteries on outcomes as well. We introduce and test a reward structure that can be utilized in any experimental setting to allow the experimenter to decree beforehand the subjects' preferences for lotteries on experimental outcomes. We show analytically that the proposed reward structure can induce subjects to behave as if they have the decreed preference function defined on experimental outcomes. Empirical tests using two different choice settings provide evidence to support this ability to control preferences.
Family Optics Day: an optics outreach event for the general public

As a way to extend the reach of optics education to a larger and more diverse audience, the Boston University student chapter of OSA/SPIE held a 'family optics day'. The outreach event was organized in a manner similar to a science fair, with participates being free to roam between a dozen demonstration stations, each focused on a different area of optics. We highlight the methods of publicity used to attract an attendance close to 300 people, and demonstrate that an event such as this is an excellent way to maximize outreach impact for a given level of organizational effort.
Instrumentation for time-resolved electron diffraction

Abstract We describe an apparatus for using electron diffraction as the probe technique in short-pulse time-resolved excite-and-probe experiments.
Si 3 O y ( y = 1 – 6 ) Clusters: Models for Oxidation of Silicon Surfaces and Defect Sites in Bulk Oxide Materials

We studied the structure and bonding of a series of silicon oxide clusters, ${\mathrm{Si}}_{3}{\mathrm{O}}_{y}$ $(y\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1--6)$, using anion photoelectron spectroscopy and ab initio calculations. For $y\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1--3$ the clusters represent the sequential oxidation of ${\mathrm{Si}}_{3}$, and provide structural models for the oxidation of silicon surfaces. For $y\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}4--6$, the clusters contain a central Si in a tetrahedral bonding environment, suggesting the onset of the bulklike structure. Evidence is presented that suggests the ${\mathrm{Si}}_{3}{\mathrm{O}}_{4}$ cluster $({D}_{2d})$ may provide a structural model for oxygen-deficient defect sites in bulk ${\mathrm{SiO}}_{2}$ materials.
Separation of powers and the Ecuadorian Supreme Court: exploring presidential–judicial conflict in a post-transition democracy

Abstract In 2005 ongoing political conflict between the executive and legislative branches of government in Ecuador culminated in a struggle over the judiciary. These events resulted in the dismissal, re-constitution, and dismissal again of the Ecuadorian high court (the Corte Suprema de Justicia) and the impeachment of the president. This paper uses the political crisis surrounding the dismissal of the Ecuadorian Supreme Court of Justice to examine the broader phenomenon of executive branch attacks on the judiciary in South American and Africa. We make three general observations: (1) the longevity of the judiciary alone (time without attack) does not guarantee a sufficiently deep reservoir of diffuse support to protect it from successful efforts at structural change or dissolution, (2) despite previous evidence that multilateral constitutional processes result in increased court independence ( Dargent, 2009 ), we conclude that multi-party institutional arrangements are more vulnerable to the types of crisis that cause them to seek to use courts and their legitimacy to achieve political goals thereby limiting previous gains in independence, and (3) a court's institutional legitimacy is enhanced when it survives political threats from other branches of government. The crisis in Ecuador is used to demonstrate the challenges facing newer democracies with continuing multilateral conflict as well as the utility of thinking about how, why and when political institutions attack high courts and how the judiciary and citizens respond.