cssi/SciSciGPT-SciSciNet huggingface dataset:
Angiotensin II Potentiates DNA Synthesis in AT-1 Transformed Cardiomyocytes ☆

Abstract Angiotensin II has been shown to be mitogenic in various cell types. In cultured neonatal cardiomyocytes, we have demonstrated that angiotensin II causes hypertrophy, not hyperplasia. However, fetal or neonatal cardiomyocytes exhibit limited proliferation in primary culture, and are mitotically less potent. In order to determine whether angiotensin II is simply a hypertrophic or hyperplastic growth factor for mitotically-potent cardiomyocytes, we analysed [ 3 H]-thymidine uptake and cell cycle-regulated gene expression using SV40 large T-transformed AT-1 cardiomyocytes. Angiotensin II, alone and in combination with other growth factors, increased [ 3 H]-thymidine uptake in a dose-dependent manner. The mRNA expression of G 1 cyclins (Cyclin C, D1, D2, D3) and histone H1-kinase activity by CDK2 increased 6 h after angiotensin II stimulation. Western blot analysis revealed cyclin B1 expression after 18 h , which peaked at 30 h. Histone H1-kinase activity by cdc2 was also increased by angiotensin II, and peaked at 24–36 h, indicating that these changes were cell cycle dependent. Double immunofluorescent photography showed that AT-1 cells incorporated BrdU, and expressed cdc2 by angiotensin II stimulation. [ 3 H]-thymidine and BrdU uptake were blocked by losartan, but not by PD123319. In contrast with neonatal cardiomyocytes, angiotensin II potentiated DNA synthesis and induced cell cycle regulated gene expression in AT-1 cardiomyocytes, and this activity was mediated by the angiotensin II type-1 receptor.
Cross Cultural Communication Competence and Multicultural Team Performance Perceptions of American and Russian Managers

Starting with the hypothesis that cross cultural communication competence affects the performance of multicultural teams, we employed the Cross Cultural Communication Competence Model to compare Am...
Dynamic estimation of an active surgical needle deflection for brachytherapy procedures

In this study, we present the dynamic response of a shape memory alloy (SMA) actuated steerable needle. The active needle can be used in many diagnostic and therapeutic percutaneous needle-based procedures. For instance brachytherapy, one the most popular prostate cancer treatments, could greatly benefit from the active needle for accurate placement of radioactive seed in target locations. In order to show the real-time deflection of the active needle under actuation of SMA wires both finite element analyses (FEA) and prototype experimentation methods were utilized. Prediction of the complex stress-strain response of SMAs due to their internal phase transformation was a challenging part of this study. Rigorous experiments were done to determine the SMA's material properties and to show a stabilized SMA transformation behavior with sufficient accuracy. A three-dimensional FE model of the active steerable needle was developed in ANSYS to demonstrate the feasibility of using SMA wires as actuators to bend the surgical needle. The birth and death method was used to achieve the pre-strain condition on SMA wire prior to actuation. This numerical simulation was validated with needle deflection experiments with developed prototypes of the active needle. Real-time experiments with different prototypes showed that the quickest response and the maximum deflection were achieved by the needle with multiple actuation sections.
Yielding behavior of glassy polymers. III. Relative influences of free volume and kinetic energy

Abstract The free-volume model for interpreting the initial yielding behavior of glassy polymers is extended to include kinetic energy influences. Molecular mobility is assumed to be determined by the product of the probabilities of attaining sufficient local free volume to allow molecular rearrangement, and kinetic energy to overcome restraining forces. Yielding then is initiated at the point where the free-volume increase resulting from the dilational component of the applied stress is sufficient to bring the local molecular mobility to that characteristic of the unstressed polymer at Tg. Expressions are derived for the temperature and strain-rate dependences of the initial yield strain (defined as the proportional limit on the tensile stress-strain curve) and compared with experimental data for poly(methyl methacrylate). The extended model is found to afford no substantial improvement over a simple free-volume model, indicating that relaxational processes in the glassy state-at least in the range Tg to...
Repetitive somatic embryogenesis in peanut cotyledon cultures by continual exposure to 2,4-d

Somatic embryos from immature cotyledons in peanut (Arachis hypogaea) were initiated on media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-d). Over 90% primary embryogenesis and 41–46% repetitive embryogenesis were obtained 12 weeks after initiation by maintaining embryogenic cultures on medium containing 20 mg 1-1 2,4-d. Maintenance of cultures on medium with 30 or 40 mg I-1 2,4-d resulted in lower primary and secondary embryogenesis, and proliferation of nonembryogenic callus. Transfer of embryogenic cultures to a secondary medium with 10 or 20 mg I-1 2,4-d significantly enhanced secondary embryogenesis compared to basal medium without the growth regulator. The use of Murashige & Skoog versus Finer's media had no significant effect on embryogenesis (85–95%), repetitive embryogenesis (11–37%) or mean embryo number. Secondary embryogenesis was also maintained for over one year by repeated subculture of isolated somatic embryos on medium with 20 mg I-1 2,4-d.
Nonlinear Limit on Primeval Adiabatic Perturbations

The amplitude of adiabatic perturbations that might have existed in the early universe is limited by the nonlinear transfer of energy to high frequencies. For flat cosmological models, this limit, together with the effect of linear dissipation, yields a residual perturbation in the matter distribution comparable with the semiempirical estimate of what is needed to produce massive galaxies.
Kanamycin in urinary tract infections in childhood.

Summary Kanamycin was used to treat 20 cases of acute and chronic urinary tract infections in childood. The drug was administered intramuscularly for 7 days in a dosage of 20 mg. per kologram per day. Kanamycin was effective in large percetage of these infections. Patients with acute infections and correctible urinary tract anomalies responded better than those with chronic infections and noncorrectible anomalies. Kanamycin appears to be another effective antibiotic for urinary tract infections in childhood. The potential ototoxic and nephrotoxic effects of the drug should be borne in mind when its use is considered.
Heterogeneous-server loss systems with ordered entry: An anomaly

We consider a loss system with Poisson arrivals and ordered entry, and we suppose that server i has service-time distribution function F"i. Consistent with the results of others, we verify that, in contrast with the classical Erlang loss system (F"i = F for all i), when F"i F"j then the loss probability is not insensitive to the form of F"i or Fj (even when F"i and F"j have the same first moment). Our main point is to note a remarkable counterintuitive fact that is an easy consequence of this result: the policy of assigning arrivals to the fastest idle server does not necessarily produce the lowest loss probability.
Should the Excess Profits Tax be Repealed

I. Theory and practise of the excess profits tax, 364.—II. Reasons for immediate repeal, 369. — 1. Prevailing opinion, 369. — 2. The income tax endangered, 370. — 3. Danger of administrative collapse, 371. — 4. "Invested capital" an insoluble problem, 374. — III. Theory of the present law: invested capital, 376. — The Excess Profits Credit, 380. — The Personal Equation, 384. — Borrowed capital, 385. — IV. Can the tax be perfected? Administrative discretion, 386. — Pre-war profits, 388. — True normal deduction, 389. — Scope of the tax, 390. — Future of the tax, 392.
Atmospheric reactions of chloroethenes with the OH radical

The kinetics and products of the homogeneous gas-phase reactions of the OH radical with the chloroethenes were investigated at 298 ± 2 K and atmospheric pressure. Using a relative rate technique and ethane as a scavenger for the chlorine atoms produced in these OH radical reactions, rate constants (in units of 10−12 cm3 molecule−1s−1) of 8.11 ± 0.24, 2.38 ± 0.14, and 1.80 ± 0.03 were obtained for 1,1-dichloroethene, cis-1, 2-dichloroethene and trans-1,2-dichloroethene, respectively. Under these conditions, the major products observed by long pathlength FT-IR absorption spectroscopy were HCHO and HC(O)Cl from vinyl chloride; HC(O)Cl from cis- and trans-1,2-dichloroethene; HCHO and COCl2 from 1,1-dichloroethene; HC(O)Cl and COCl2 from trichloroethene; and COCl2 from tetrachloroethene. In the absence of a Cl atom scavenger, significant yields of the chloroacetyl chlorides, CHxCl3−xC(O)Cl, were observed from 1,1-dichloro-, trichloro- and tetrachloroethene, indicating that these products resulted from reactions involving chlorine atoms. The yields of all of these products are reported and the mechanisms of these gas-phase reactions discussed. In addition, OH radical reaction rate constants were redetermined, in the presence of a Cl atom scavenger, for cis- and trans-1,3-dichloropropene and 3-chloro-2-chloromethyl-1-propene, being (in units of 10−12 cm3 molecule−1 s−1) 8.45 ± 0.41, 14.4 ± 0.8, and 33.5 ± 3.0, respectively.
Effective cancellation policy to reduce the negative impact of patient no-show

AbstractThe problem of patient no-show in outpatient delivery systems has been a long recognized issue. The negative impacts include underutilized medical resources, increased healthcare costs, dec...
Comparative approaches to equipment scheduling in high volume factories

Mail processing and distribution centers (P&DCs) are large factories that accept, sort, and sequence mail in preparation for delivery. A central problem in these facilities is how to schedule the equipment over the day to ensure batch production under tight equipment and workforce constraints. The problem falls into the general category of multi-level lot sizing and is notoriously difficult to solve. No exact algorithms exist that are efficient and can consistently provide high-quality solutions. In the paper, we investigate two specialized approaches for solving this problem. The first is a piece-by-piece LP-based heuristic and the second is a Benders decomposition. The heuristic uses the LP fractional solution as a target and attempts to find an integer solution that is as close to it as possible by minimizing the L"1-norm. The procedure consists of solving the LP relaxation of the original model and two reduced mixed-integer programs. The process is similar to what has been called 'piece-by-piece decomposition' in nonlinear programming. While the goal there is to find better initial starting points for the nonlinear code, our goal is to improve solution quality. Computational testing using data provided by the Dallas P&DC confirmed the superiority of the piece-by-piece LP-based heuristic with respect to branch and bound, which proved to be computational expensive, and the Benders algorithm which took several hours to find feasible solutions. In general, the LP-based heuristic was an order of magnitude faster than branch and bound and provided solutions that were able to process more than 99.75% of the daily volume.
Mechanical properties of self-welded silicon nanobridges

Mechanical properties of self-welded [111] single-crystal silicon nanowire bridges grown between two silicon posts using metal-catalyzed chemical vapor deposition were determined using both dynamic and static measurements. The static tests were carried out using atomic force microscopy (AFM) to measure the nanowires’ Young’s modulus and the strength of the self-welded junctions. The AFM-measured Young’s modulus ranged from 93 to 250 GPa (compared to 185 GPa for bulk silicon in the [111] direction) depending on the nanowire diameter, which ranged from 140 to 200 nm. The self-welded wire could withstand a maximum bending stress in the range of 210–830 MPa (larger than bulk silicon), which also depended on the nanowire diameter and loading conditions. The beam broke close to the loading point, rather than at the self-welded junction, indicating the excellent bond strength of the self-welded junction. The vibration spectra measured with a network analyzer and a dc magnetic field indicated a dynamic Young’s mo...
A new approach to Macaulay posets

We develop a new approach for establishing the Macaulayness of posets representable as cartesian powers of other posets. This approach is based on a problem of constructing an ideal of maximum rank in a poset. Using the relations between the maximum rank ideal problem and the edge-isoperimetric problem on graphs we demonstrate an application of our approach to specification of all posets with a special Macaulay order. We also present a new general construction for additive Macaulay posets and introduce several new families of Macaulay posets.
After the starting line: blacks and women in an uphill race.

This study which formed the Presidential Address to the 1988 Annual Meeting of the Population Association of America is concerned with the changing role of blacks and women in contemporary U.S. society. The focus is on the integration of blacks into the economy and on the changing composition of black families. The author argues that the continuing high poverty rate among blacks can only be understood in the context of three major social changes: the civil rights revolution of the 1960s shifts in employment and industry and changes in the social and economic roles of women. He concludes that "largely because of changes in family patterns many black women and an increasing proportion of white women face spans--often when they have custody of children--during which their incomes put them near or below the poverty line....[and that] the changes in family structure that occurred among blacks are a leading indicator of what may happen among whites." The importance of having demographers contribute to the debate on policy alternatives concerning the reduction of poverty the future of the family and affirmative action is stressed. (EXCERPT)
Motivational systems and the neural circuitry of maternal behavior in the rat

Jay Rosenblatt's approach-avoidance model of maternal behavior proposes that maternal behavior occurs when the tendency to approach infant stimuli is greater than the tendency to avoid such stimuli. Our research program has uncovered neural circuits which conform to such a model. We present evidence that the medial preoptic area (MPOA: located in the rostral hypothalamus) may regulate maternal responsiveness by depressing antagonistic neural systems which promote withdrawal responses while also activating appetitive neural systems which increase the attractiveness of infant-related stimuli. These MPOA circuits are activated by the hormonal events of late pregnancy. Preoptic efferents may suppress a central aversion system which includes an amygdala to anterior hypothalamic circuit. Preoptic efferents are also shown to interact with components of the mesolimbic dopamine (DA) system to regulate proactive voluntary maternal responses. We make a distinction between specific (MPOA neurons) and nonspecific motivational systems (mesolimbic DA system) in the regulation of maternal responsiveness. © 2006 Wiley Periodicals, Inc. Dev Psychobiol 49: 12–21, 2007.
Leishmania in the Chick Embryo. II. Effects of Inoculum Size, Strain Origin, and Stage Injected and Infectivity of Embryo‐Derived Parasites for Hamsters*

SYNOPSIS. Amastigotes of Leishmani donovani strains 2S, 3S, 3K, Hm, Gm, and Et were inoculated intravenously into 14-day chick embryos. The course of infection was followed by examinations of liver impression smears. With strain 33 at 33 C incubation, there was a 29-fold increase at 6 days postinfection when the inoculum contained ∼4 × 106 amastigotes, but only a ∼6.3-fold increase when ∼64 × 106 parasites were injected. Infection courses of several geographic strains were compared at 30, 33, and 35 C incubation. Although the results were variable, Sudan strains 2S and 3S appeared to be separate isolations of a single strain. The Burma (Et), Kenya (3K), and Mediterranean (Hm, Gm) strains appeared to be distinct, but confirming evidence of their distinctness should be sought using serologic, epidemiologic, clinical, and biochemical criteria. Strains 2S and 3S multiplied best at 33 C or below, but the embryos usually failed to survive at 28 or 30 C. Multiplication was inhibited partially at 35 C and completely at 37 C. Inoculation of strain 3S promastigotes into chick embryos resulted in a loss of parasites in 1 hr to 2 days postinfection. Only amastigotes were seen in embryos incubated at 28 and 33 C for 4 days. Hamsters infected with parasites passaged once in chick embryos died at median postinoculation times that were closely comparable to those noted among hosts infected with amastigotes from hamster spleen.
Conductivities of solid polymer electrolyte complexes of alkali salts with polymers of methoxypolyethyleneglycol methacrylates

Abstract The ac conductivities of solid polyelectrolyte complexes of alkali salts (NaSCN, NaCF3SO3, LiCF3SO3, LiCF3SO3) with polymers derived from methoxypolyethyleneglycol methacrylates of the general formula CH2 = C(CH3)COO(CH2CH2O) nCH3 (n = 8, 22) were measured as a function of temperature and salt content. The salts from crystalline or amorphous complexes with the polymers, some with a CH2CH2O to cation ratio as low as unity. The results were compared with the thermal characteristics of the complexes obtained from differential scanning calorimeter measurements. Crystallinity is reduced and conductance enhanced by lowering the salt content, adding an external plasticizer like propylene carbonate or by incorporating a comonomer like styrene into the polymer. The Arrhenius conductance plots are linear, and the conductivities with those reported for alkali salt complexes with poly (ethylene oxide).
FACTORS AFFECTING PARELAPHOSTRONGYLUS TENUIS IN WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) FROM MAINE

White-tailed deer (Odocoileus virginianus) collected in Maine (USA) from November 1988 to December 1989 were examined for Parelaphostrongylus tenuis. Relationships of deer age class, sex, collection year, and deer density to prevalence and intensity of P. tenuis infections were analyzed. Prevalence increased with deer age (P 0.50) nor intensity (P > 0.50) of infection was associated with deer density over a range of 1.4 to 5.8 deer per km2. Heads and fecal samples from the same individuals (n =...
The nature and prevention of prosthetic valve endocarditis

Abstract Infection upon ball valve prostheses is a significant cause of death, especially in the early postoperative period. Such infection may occur in the late postoperative period, in which case it almost always is associated with infection elsewhere in the body, or follows unrelated surgical procedures or other predisposing events. Staphylococcus is the most frequent cause of this form of bacterial endocarditis. The diagnosis is often disregarded because bacterial endocarditis has nonspecific manifestations early in the disease. Bacterial endocarditis can be virtually eliminated with 10 days or more of methicillin and oxacillin prophylasis .
Oxygen consumption of the scorpion centruroides sculpturatus

Abstract 1. 1. Rhythmic fluctuations in oxygen consumption and the effects of sex, body size, age and temperature on respiratory rates were investigated for the scorpion, Centruroides sculpturatus . 2. 2. A nocturnal rhythm in oxygen consumption was not observed except for an initial increase in response to the change from light to dark. 3. 3. Higher oxygen consumption rates were found for males. This probably reflects a size difference between the sexes. 4. 4. Oxygen consumption showed an essentially linear increase between 10 and 42°C. At higher temperatures approaching lethal limits, a sharp rate increase was followed by a decrease in oxygen consumption. 5. 5. Observed rhythmic fluctuations and respiration-temperature curves are discussed in relation to scorpion activity.
Mars: Aeolian features and wind predictions at the Terra Meridiani and Isidis Planitia potential Mars Exploration Rover landing sites

[1] Orientations of 11,497 aeolian (wind related) features at the potential Mars Exploration Rover (MER) landing site in Isidis Planitia reflect formative winds from the northwest and are consistent with strong morning winds predicted by a regional-scale atmospheric model for Mars. Orientations of 3296 aeolian features mapped at the Terra Meridiani potential MER site suggest multidirectional wind patterns. The results for the Terra Meridiani site are consistent with gentle winds which change direction as a function of Martian season (predicted by a general circulation model) and erratic winds that occur diurnally (predicted by a regional-scale atmospheric model). Results for both sites give confidence that the predictions from the atmospheric models are basically correct when time of day and local topography are taken into account.
DOES THE EMPEROR HAVE NEW CLOTHES?, a Reply to Robert J. Baade

(1996). Does the Emperor Have New Clothes?, a Reply to Robert J. Baade. Journal of Urban Affairs: Vol. 18, No. 1, pp. 23-31.
Recent Advances in Molecular Scale Electronics

ABSTRACT: This paper describes four significant breakthroughs in the syntheses and testing of molecular scale electronic devices. The 16-mer of oligo(2-dodecylphenylene ethynylene) was prepared on Merrifield's resin using the iterative divergent/convergent approach which significantly streamlines the preparation of this molecular scale wire. The formation of self-assembled monolayers (SAMs) and multilayers on gold surfaces of rigid rod conjugated oligomers that have thiol, α,ω-dithiol, thioacetyl, or α,ω-dithioacetyl end groups have been studied. The direct observation of charge transport through molecules of benzene-1,4-dithiol, which have been self-assembled onto two facing gold electrodes, has been achieved. Finally, we are reporting initial studies into what effect varying the molecular alligator clip has on the molecular scale wire's conductivity.
Influence of Target Concentration and Background Binding on In Vitro Selection of Affinity Reagents

Nucleic acid-based aptamers possess many useful features that make them a promising alternative to antibodies and other affinity reagents, including well-established chemical synthesis, reversible folding, thermal stability and low cost. However, the selection process typically used to generate aptamers (SELEX) often requires significant resources and can fail to yield aptamers with sufficient affinity and specificity. A number of seminal theoretical models and numerical simulations have been reported in the literature offering insights into experimental factors that govern the effectiveness of the selection process. Though useful, these previous models have not considered the full spectrum of experimental factors or the potential impact of tuning these parameters at each round over the course of a multi-round selection process. We have developed an improved mathematical model to address this important question, and report that both target concentration and the degree of non-specific background binding are critical determinants of SELEX efficiency. Although smaller target concentrations should theoretically offer superior selection outcome, we show that the level of background binding dramatically affect the target concentration that will yield maximum enrichment at each round of selection. Thus, our model enables experimentalists to determine appropriate target concentrations as a means for protocol optimization. Finally, we perform a comparative analysis of two different selection methods over multiple rounds of selection, and show that methods with inherently lower background binding offer dramatic advantages in selection efficiency.
The broad spectrum of responses to oxidants in proliferating cells: a new paradigm for oxidative stress.

Proliferating mammalian cells exhibit a broad spectrum of responses to oxidative stress, depending on the stress level encountered. Very low levels of hydrogen peroxide, e.g., 3 to 15 microM, or 0.1 to 0.5 micromol/10(7) cells, cause a significant mitogenic response, 25% to 45 % growth stimulation. Greater concentrations of H2O2, 120 to 150 microM, or 2 to 5 micromol/10(7) cells, cause a temporary growth arrest that appears to protect cells from excess energy use and DNA damage. After 4-6 h of temporary growth arrest, many cells will exhibit up to a 40-fold transient adaptive response in which genes for oxidant protection and damage repair are preferentially expressed. After 18 h of H2O2 adaptation (including the 4-6 h of temporary growth arrest) cells exhibit maximal protection against oxidative stress. The H2O2 originally added is metabolized within 30-40 min, and if no more is added the cells will gradually de-adapt, so that by 36 h after the initial H2O2 stimulus they have returned to their original level of H2O2 sensitivity. At H2O2 concentrations of 250 to 400 microM, or 9 to 14 micromol/10(7) cells, mammalian fibroblasts are not able to adapt but instead enter a permanently growth-arrested state in which they appear to perform most normal cell functions but never divide again. This state of permanent growth arrest has often been confused with cell death in toxicity studies relying solely on cell proliferation assays as measures of viability. If the oxidative stress level is further increased to 0.5 to 1.0 mM H2O2, or 15 to 30 micromol/10(7) cells, apoptosis results. This oxidative stress-induced apoptosis involves nuclear condensation, loss of mitochondrial transmembrane potential, degradation/down-regulation of mitochondrial mRNAs and rRNAs, and degradation/laddering of both nuclear and mitochondrial DNA. At very high H2O2 concentrations of 5.0 to 10.0 mM, or 150 to 300 micromol/10(7) cells and above, cell membranes disintegrate, proteins and nucleic acids denature, and necrosis swiftly follows. Cultured cells grown in 20% oxygen are essentially preadapted or preselected to survive under conditions of oxidative stress. If cells are instead grown in 3% oxygen, much closer to physiological cellular levels, they are more sensitive to an oxidative challenge but exhibit far less accumulated oxidant damage. This broad spectrum of cellular responses to oxidant stress, depending on the amount of oxidant applied and the concentration of oxygen in the cell culture system, provides for a new paradigm of cellular oxidative stress responses.
Singular Nonlinear (k, n−k) Conjugate Boundary Value Problems

Abstract For 1⩽ k ⩽ n −1, solutions are obtained for the boundary value problem, (−1) n − k y ( n ) = f ( x , y ), y ( i ) (0)=0, 0⩽ i ⩽ k −1, and y ( j ) (1)=0, 0⩽ j ⩽ n − k −1, where f ( x , y ) is singular at y =0. An application is made of a fixed point theorem for operators that are decreasing with respect to a cone.
Simultaneous interferometric optical-figure characterizations for two optical elements in series: Proposal for a non-Newtonian numerical integration scheme

The article proposes a scheme to break a Catch-22 loop in an optical-figure–wavefront measurement. For instance, to measure the tilt-independent optical figure of a nominal optical flat at cryogenic temperatures, one requires a cryogenic Dewar-window system for a Fizeau interferometer mainframe outside the Dewar to see through. The problem is: how to calibrate the window system in situ using the yet-to-be-calibrated nominal optical flat, and vice versa, in only one cryogenic cooldown? The proposal includes: (a) interferometric phase-map measurements with the test piece slightly offset in different transverse directions, and (b) an unconventional numerical integration scheme, starting with one-dimensional bidirectional integrations, to synthesize the two-dimensional wavefront distortion function. The numerical scheme helps minimize the nonuniformity in noise-power distribution that results from integrating phase-map data, and thus the associated uncorrelated random noise. The numerical integration scheme represents a non-Newtonian concept specifically for noise-carrying experimental data. The algorithm that determines the algorithm for the domain-shape-specific integration scheme is described in detail.
Factors influencing the 17O quadrupole coupling constant in bridging oxygen environments

Abstract Ab initio calculations were performed on the series of clusters [(OH)3MOM(OH)3]−2 where M=B, Al, and Ga, (OH)3MOM(OH)3 where M=C, Si, and Ge, (OH)2OMOMO(OH)2 where M=P and As, and (OH)O2MOMO2(OH) where M=S and Se. These clusters were constructed to model the effect of changing the coordinating cation and coordinating cation–oxygen distances on the bridging oxygen 17O quadrupole coupling constant. For all clusters studied, we observed a general trend that the magnitude of Cq increases linearly with increasing cation–oxygen bond distance and cation group number, suggesting that group number and cation-bridging oxygen distance can serve as a better predictor of the bridging oxygen quadrupole coupling constant than electronegativity differences.
7-CHLORO-3-METHYL-3,4-DIHYDRO-2H-1,2,4-BENZOTHIADIAZINE S,S-DIOXIDE : A PARTIAL MODULATOR OF AMPA RECEPTOR DESENSITIZATION DEVOID OF NEUROTOXICITY

In cerebellar granule neurons of neonatal rats micromolar concentrations of 7-chloro-3-methyl-3,4-dihydro-2H-1,2,4-benzothiadiazine S,S-dioxide (IDRA-21) and cyclothiazide, two negative modulators of the spontaneous agonist-dependent rapid desensitization of α-amino-3-hydroxy-5-methylisoxazolepropionic acid (AMPA)-gated ion channels, facilitate AMPA receptor function by increasing the content of free cytosolic Ca2+ as measured by single-cell fura-2 acetoxymethyl ester (Fura-2) Ca2+-dependent fluorescence and intracellular Na+ measured with the sodium-binding bezofuran isophthalate acetoxymethyl ester fluorescence indicator. IDRA-21 increases intracellular Na+ transient with a threshold (5 μM) that is ≈10 times higher and has an intrinsic activity significantly lower than that of cyclothiazide. By virtue of its low intrinsic activity, IDRA-21 elicits a free cytosolic Ca2+ transient increase that is shorter lasting than that elicited by cyclothiazide even when the drug is left in contact with cultured granule cells for several minutes. Additionally, while dose dependently, 5–25 μM cyclothiazide in the presence of AMPA is highly neurotoxic, IDRA-21 (up to 100 μM) is devoid of neurotoxicity. The neurotoxicity elicited by cyclothiazide persists in the presence of dizocilpine (an antagonist of N-methyl-d-aspartate-selective glutamate receptors) but is blocked by 2,3-dihydroxy-6-nitrosulfamoylbenzo[f]quinoxaline (a competitive AMPA receptor antagonist) and the 1-(aminophenyl)-4-methyl-7,8-methylendioxy-5H-2,3-benzodiazepine (GYKI 52466; a noncompetitive AMPA receptor antagonist). Since the doses of IDRA-21 that enhance cognitive processes in rats and monkeys are several orders of magnitude lower than those required to elicit marginal neurotoxicity in cultured neurons, it can be surmised that IDRA-21 is a potent cognition-enhancing drug virtually devoid of neurotoxic liability because it acts as a partial negative allosteric modulator of AMPA receptor desensitization.
940 ASYNCHRONOUS ONSET OF μ AND LIGHT CHAIN SYNTHESIS BY HUMAN PRE-B CELLS

Pre-B cells, precursors of surface IgM bearing B cells, are defined as cells in hemopoietic tissues that lack surface immunoglobulins (sIg-) but produce small amounts of cytoplasmic IgM components (cμ+). To determine whether Ig light chains and other heavy chains are also produced by pre-B cells, we have used affinity purified goat antibodies to human Ig determinants (μ, δ, γ, α, κ, λ) in immunofluorescent and immunochemical assays of bone marrow samples. All sIg+ B cells and cIg+ plasma cells were costained with a mixture of anti-κ and anti-λ antibodies. None of the cIg+ plasma cells were double stained with anti-κ and anti-λ. κ/λ ratios of sμ+ B cells and cIg+ plasma cells from 5 normal adult marrows were 1.4 ± 0.2 and 1.3 ± 0.3 (mean ± S.D.), respectively. Frequencies (%) of pre-B cells (sIg-cμ+), κ+ pre-B cells (sIg-Cμ+) and λ+ pre-B cells (sIg-cμ+) among nucleated bone marrow cells were 0.69 ± 0.38, 0.017 ± 0.015 and ≤0.008, respectively. Pre-B cells expressing Ig heavy chains other than μ were not seen among 30,000 or more nucleated marrow cells. Analysis of bone marrow cells from two patients with X-linked agammaglobulinemia revealed μ chain synthesis only, as determined by SDS polyacrylamide gel electrophoresis. Our data indicate that (i) >90% of human pre-B cells express μ chains only, suggesting asynchronous onset of heavy and light chain synthesis, and (ii) heavy chain switching is a rare event at this stage in differentiation.
MAN AND WOMAN: SOCIAL SCHEMATA OF MALES AND FEMALES

Male and female college students placed human figures cut from felt on a felt field. Ss were free to arrange the figures in any manner. Both male and female Ss used the same generic social schemata; human figures were kept together, male figures were placed with female figures, and figures were rarely paired with same-sex figures. Differences between the male and female Ss included the tendency of the female Ss to form male-female pairings separated away from other figures. The use of aggressive schemata was studied as were preferences for non-social orderings.
Third order oscillators with independently adjustable frequency, amplitude and transient response

A class of third order harmonic oscillators with frequency, amplitude and transient response controlled by three separate sets of parameters is derived. A simplified group of oscillators is described in which there are only three parameters, one which controls the frequency, another the amplitude, and the third the transient response. Each oscillator contains a single nonlinearity, which can be either of the saturation or the dead space type. The mathematical analysis is based on linearizing the nonlinearity by means of the sinusoidal describing function. The transient response is studied by considering small amplitude perturbations away from the oscillator's limit cycle. The results of analogue computer simulations are presented with emphasis on the relationship between transient response and the gain controlling it.
Signal detection models with random participant and item effects

The theory of signal detection is convenient for measuring mnemonic ability in recognition memory paradigms. In these paradigms, randomly selected participants are asked to study randomly selected items. In practice, researchers aggregate data across items or participants or both. The signal detection model is nonlinear; consequently, analysis with aggregated data is not consistent. In fact, mnemonic ability is underestimated, even in the large-sample limit. We present two hierarchical Bayesian models that simultaneously account for participant and item variability. We show how these models provide for accurate estimation of participants’ mnemonic ability as well as the memorability of items. The model is benchmarked with a simulation study and applied to a novel data set.
The molecular basis of factor V and VIII procofactor activation

Activation of precursor proteins by specific and limited proteolysis is a hallmark of the hemostatic process. The homologous coagulation factors (F)V and FVIII circulate in an inactive, quiescent state in blood. In this so-called procofactor state, these proteins have little, if any procoagulant activity and do not participate to any significant degree in their respective macromolecular enzymatic complexes. Thrombin is considered a key physiological activator, cleaving select peptide bonds in FV and FVIII which ultimately leads to appropriate structural changes that impart cofactor function. As the active cofactors (FVa and FVIIIa) have an enormous impact on thrombin and FXa generation, maintaining FV and FVIII as inactive procofactors undoubtedly plays an important regulatory role that has likely evolved to maintain normal hemostasis. Over the past three decades there has been widespread interest in studying the proteolytic events that lead to the activation of these proteins. While a great deal has been learned, mechanistic explanations as to how bond cleavage facilitates conversion to the active cofactor species remain incompletely understood. However, recent advances have been made detailing how thrombin recognizes FV and FVIII and also how the FV B-domain plays a dominant role in maintaining the procofactor state. Here we review our current understanding of the molecular process of procofactor activation with a particular emphasis on FV.
Pathogenesis of human hemangiosarcomas and hemangiomas

Hemangiosarcomas are uncommon aggressive vascular tumors that have recently become the focus of attention because several chemicals and pharmaceuticals increase their incidence in mice. The relevance of these mouse vascular tumors to humans is unclear. In the present study, we semiquantitatively evaluated the expression profiles of hematopoietic stem cell markers (CD117 [c-kit], CD133, CD34, and CD45), endothelial cell markers (vascular endothelial growth factor receptor 2, CD31, and factor VIII-related antigen), and a myeloid lineage cell marker (CD14) in human hemangiosarcoma (n = 12) and hemangioma (n = 10) specimens using immunohistochemistry. CD133 was completely negative in almost all cases of hemangiosarcomas and hemangiomas. Most hemangiosarcomas, but not hemangiomas, stained for CD117 and CD45. Both groups diffusely expressed CD34, vascular endothelial growth factor receptor 2, and factor VIII-related antigen; however, hemangiomas had more intense and diffuse CD34 and factor VIII-related antigen expression compared with hemangiosarcomas, whereas CD31 was positive in all hemangiosarcomas but only half of the hemangiomas. CD14 staining was negative in most hemangiosarcoma and hemangioma cases. Our results indicate that multipotential bone marrow-derived hematopoietic stem cells or early endothelial progenitor cells (EPCs) expressing CD117, CD34, and CD45 are involved in hemangiosarcoma formation, whereas hemangiomas originate from late EPCs or differentiated endothelial cells, which have lost the expression of most hematopoietic stem cell markers. This contrasts with our previous results that demonstrated that both hemangiosarcomas and hemangiomas in mice may be derived from early EPCs that are not completely differentiated.
Phospholipase D (PLD) gene expression in human neutrophils and HL-60 differentiation

Human neutrophils exhibit a regulated phospholipase D (PLD) activity that can be mea- sured biochemically in vitro. However, the precise expression pattern of PLD isoforms and their spe- cific biological role(s) are not well understood. Neutrophil mRNA is intrinsically difficult to isolate as a result of the extremely high content of lytic enzymes in the cell's lysosomal granules. Reverse transcriptase coupled to polymerase chain reaction indicated that pure populations of human neutro- phils had the CD16b/CD115/CD20/CD3/in- terleukin-5 receptor phenotype. These cells expressed the following splice variants of the PLD1 isoform: PLD1a, PLD1b, PLD1a2, and PLD1b2. As for the PLD2 isoform, neutrophils expressed the PLD2a but not the PLD2b mRNA variant. The relative amount of PLD1/PLD2 transcripts exists in an approximate 4:1 ratio. The expression of PLD isoforms varies during granulocytic differen- tiation, as demonstrated in the promyelocytic leu- kemia HL-60 cell line. Further, the pattern of mRNA expression is dependent on the differentia- tion-inducing agent, 1.25% dimethyl sulfoxide causes a dramatic increase in PLD2a and PLD1b transcripts, and 300 nM all-trans-retinoic acid in- duced PLD1a expression. These results demon- strate for the first time that human neutrophils express five PLD transcripts and that the PLD genes undergo qualitative changes in transcription regulation during granulocytic differentiation. J. Leukoc. Biol. 77: 000-000; 2005.
A Mutant Arabidopsis Heterotrimeric G-Protein β Subunit Affects Leaf, Flower, and Fruit Development

A genetic screen was performed to find new mutants with an erecta (er) phenotype and to identify genes that may function with ER, a receptor-like kinase. These mutants were named elk (for erecta-like) and were placed into five complementation groups. We positionally cloned ELK4 and determined that it encodes AGB1, a putative heterotrimeric G-protein beta subunit. Therefore, elk4 was renamed agb1. agb1-1 plants express similar fruit phenotypes, as seen in er plants, but differ from er in that the stem is only slightly shorter than that in the wild type, the pedicel is slightly longer than that in the wild type, and the leaves are rounder than those in er mutants. Molecular analysis of agb1-1 indicates that it is likely a null allele. AGB1 mRNA is expressed in all tissues tested but is highest in the silique. Analysis of agb1-1 er double mutants suggests that AGB1 may function in an ER developmental pathway regulating silique width but that it functions in parallel pathways affecting silique length as well as leaf and stem development. The finding that AGB1 is involved in the control of organ shape suggests that heterotrimeric G-protein signaling is a developmental regulator in Arabidopsis.
Differences in structure and stability between normal and deuterated proteins (phycocyanin)

Differential scanning microcalorimetry was used to investigate the enthalpy (ΔHd) and the temperature (td) of thermal denaturation of normal and deuterated phycocyanins isolated from two blue-green algae, Plectonema calothricoides and Phormidium luridum. Values of td in deuterated proteins are about 5°C lower than those in normal proteins. The magnitudes of ΔHd in deuterated proteins are 18–36% lower than in normal proteins. The heatcapacity change (ΔCp) in protein unfolding is essentially the same (2 kcal/mol/K) for deuterated and normal proteins within the experimental error. At close to physiological temperature (27°C), the differences in thermodynamic functions in the native and denatured states are much higher in normal proteins than in deuterated proteins. CD was employed to evaluate both the secondary structures and urea denaturation of these two types of proteins. In P. luridum, deuterated protein is about 8% higher in α-helix content; in P. calothricoides it is not significantly higher. Deuterated proteins are less resistant to the denaturant urea than are normal proteins: the denaturant concentration at the midpoint of the denaturation curve is 0.6–1.2 mol/L lower in the deuterated proteins. The apparent free energies of unfolding of deuterated proteins at zero denaturant concentration are 1.1–1.5 kcal/mol less than for normal proteins.
An Educational Needs Assessment of Pennsylvania Workforce: Opportunities to Redefine Secondary Career and Technical Education to Meet Food Industry Needs

This article describes the outcomes of a needs assessment concerning current training needs and performance targets for non-degreed employees in the food industry. Focus groups were used to gather data from 5 food-processing companies: a fresh vegetable company, a canned vegetable company, 2 snack food companies, and a meat company. Focus group participants consisted of 1 senior- level manager each from human resource, pro- duction, quality assurance, purchasing, and product development departments within each company. The needs assessment identified 4 major themes that employers indicated as ben- eficial knowledge and skills for employees to possess: safety training, knowledge of food and production systems, learning and applying mathematical skills, and professional conduct. The authors anticipate that the knowledge of industry needs, with respect to the desired in- coming workforce competencies and knowl- edge, will facilitate the development of inte- grated curriculum modules for secondary ca- reer and technical education programs (high school grades). These integrated curriculum modules will address the growing needs of the food industry and facilitate the development of employment skills required to function and prosper in the new global economy.
Parent-Child Joint Picture-Book Reading among Children with ADHD.

Objective: Children with AD/HD exhibit two disparate areas of difficulty: disrupted interactions with parents and significant problems in story comprehension. This study links these two difficulties by examining parent—child joint picture-book reading to determine whether there were diagnostic group differences in parent and child storytelling. Method: Parents of 25 children with ADHD and 39 comparison children (mean age = 7.5 years) told their children a story based on a wordless picture-book, and children then retold the story to an examiner from memory. Results: Parents in both groups told stories of similar length and complexity and demonstrated similar affective and responsive quality. The length of the child's retell of the parent's story did not differ across groups but children with ADHD included fewer goal-based events. Conclusions: Results are discussed in terms of implications for enhancing the quality and frequency of parent—child storytelling among children with ADHD. (J. of Att. Dis. 2009; 1...
Critical-to-quality factors associated with engineering student persistence: the influence of freshman attitudes

National studies have revealed numerous explanations for the lack of student persistence toward a science, math, or engineering degree. At many institutions, the greatest predictor of student success has been shown to be a combination of high school grades and SAT scores. However, at Mercer University, regression analyses show that differences in high school grade point averages and SAT scores account for less than 25% of the variability in the data describing student persistence toward an undergraduate degree. We believe that student attitudes and perceptions influence decisions to remain in an engineering curriculum, and have developed a series of studies to test this hypothesis. The current study focused on a cohort of students who entered our engineering school as first-time, full-time freshmen in the fall 2000 semester. We found significant attitudinal and belief differences between those who left engineering and those who persisted to the fourth year of college. Five critical-to-quality factors were identified.
Structure–property relationships of antibacterial amphiphilic polymers derived from 2-aminoethyl acrylate

The findings from the investigation of an ensemble of amphiphilic polymers derived from 2-aminoethyl acrylate establish significant effects of variation in the topographical position of the cationic center and hydrophobic segments on their biological activities. For example, the isomeric polymer pair of poly(6-aminohexylacrylate) and poly(2-(butylamino)ethyl acrylate) show striking differences in their biological activities, with the former having biological activities orders of magnitude higher. The trend of the activities of alkyl tails attached to the charge center shows an abrupt increase in biological activity at butyl length in the series of methyl to butyl tail. The distribution and interaction of the charge center in the chain domain is one of the main parameters in influencing polymer activities. Within the 2-aminoethyl acrylate system of homo- and copolymer, the homopolymer has its cationic centers closely distributed along the amphiphilic macromolecular chain with proximity to the backbone leading to rigid conformations not conducive to the attachment of the polymer to the cell surface. In copolymers, the incorporation of uncharged counits increases the distance between the cationic centers, resulting in significant reduction of charge repulsion and thus enhancing the flexibility of the chain conformation. This is conducive for polymer-cell association, leading to a remarkable surge in orders of magnitude of biological activity but with low selectivity against bacteria over red blood cells.