cssi/SciSciGPT-SciSciNet huggingface dataset:
Differences in cutaneous sensory response properties of single somatosensory cortical neurons in awake and halothane anesthetized rats.

The major aim of this study was to investigate the effect of halothane anesthesia on different latency components of cutaneous sensory responses of single units in the primary somatosensory (SI) cortex of rats. Quantitative studies of computer generated post-stimulus time histograms were used to determine whether the increase in “nonspecific” properties often observed in the SI cortices of awake animals were attributable to a generally increased sensory responsiveness of these cells or to a selective increase of certain “nonspecific” components of their sensory response. Sensory “specificity” was investigated here by measuring the size of cutaneous receptive fields of single cells and testing their ability to follow high stimulus frequencies. Histograms generated by repetitive touch stimulation of the forepaw in awake animals were divisible into the following different latency components: (1) a short latency excitatory response which was often divisible into two peaks (Ela and Elb), and occasionally (2) a post-excitatory inhibitory phase (11) and/or (3) a long latency excitatory peak (E2). In anesthetized animals spontaneous discharge rates were lower and the proportion of cells exhibiting either pure inhibition or post-excitatory inhibition was increased. By contrast, the longer latency excitatory components (Elb and E2) were weaker and were seen much less frequently than in the awake situation. In nine cells tested in the awake state and then again in the anesthetized state the magnitude, receptive field size, and ability to follow high frequencies of the Ela peak was slightly reduced. The Elb and E2 peaks seen in the awake state, on the other hand, were completely abolished by anesthesia. In awake animals the Elb and E2 phases exhibited relatively “nonspecific” physiological properties. This was indicated by the facts that: (1) the cutaneous receptive fields of the Ela peak were slightly smaller than those of the Elb peaks and much smaller than those of the E2 peaks, and (2) the Ela peak was able to follow higher frequencies of touch stimulation than the Elb or E2 peaks. It is concluded therefore that although halothane anesthesia slightly depressed the short latency response component (E1a) exhibiting highly specific sensory properties, its main effect was to depress the longer latency excitatory components (Elb and E2) which exhibited relatively “nonspecific” properties.
Control of Machine Tools and Robots

The principal control structure of CNC machine tools and industrial robots is similar, since in both systems each axis of motion is separately controlled with a position feedback loop. Nevertheless, the control of robots is more complex, since they include more degrees of freedom and the motion of each joint is not independent of other joints. This paper compares the conventional control schemes of both systems, and summarizes recent developments in adaptive control of machine tools and robots.
Climate engineering a review of aerosol approaches to changing the global energy balance

As global greenhouse warming continues to intensify, it is likely that demands to employ technologies of climate engineering will become increasingly insistent. This paper addresses the possibility of ‘canceling’ the radiative effects of the increasing greenhouse gases through solar reflectors. Two promising approaches, according to COSEPUP (1992), are the employment of aerosols in the stratosphere, directly as reflectors, or in the troposphere, for the ‘seeding’ of clouds to increase cloud amounts and brightness. Besides technological and economic feasibility, such schemes could be relatively reversible, and describing their impact may be within the reach of future scientific study. The climate system is not yet sufficiently understood for such actions to be warranted. However, there is considerable potential for an increased understanding of what such actions might do through the study of the role of similar aerosols already added to the climate system. In particular, the most intense volcanoes (e.g. Pinatubo) supply the stratosphere with enough aerosol over a period of a year or two to cancel out greenhouse warming from a resulting doubling of carbon dioxide. Furthermore, the addition of sulfate aerosols to the troposphere from the burning of fossil fuel may already be canceling out globally up to half of the greenhouse-gas warming. These comparisons suggest that at least 10 times as much sulfate aerosol would be needed in the troposphere as would be needed in the stratosphere for a comparable climatic effect. A better understanding of the role of the already-present aerosols is a prerequisite for further progress in the use of aerosols for climate engineering. The links between the horizontal and vertical distribution of radiative sources and sinks and various atmospheric feedback processes, especially those related to the hydrological cycle and the consequent global and regional responses, are also needed.
Modeling Unpairing Costs for Fast Computation of the Net Binding Free Energy of an Oligo to an mRNA Target

View Large Image | View Hi-Res Image | Download PowerPoint SlideBinding of a small RNA (miRNA, snoRNA, siRNA) often regulates the expression of messenger RNA. The net free energy consists of the contribution of binding, which is well parameterized and fast to compute, offset by the penalty to remove pre-existing mRNA secondary structure, which is O(N3) to compute with previous methods. Here we introduce a base-composition-dependent model for the mean free energy to open the target which runs in O(N). Implemented in our BINDIGONET algorithm, this model for the net binding free energy of spliceosomal U1-snRNA to real and decoy donor splice sites enhances accuracy.
Development of x-ray induced giant HeLa cells.

Abstract HeLa S3 cells increase in volume and mass exponentially, without lag, following doses of 1200 or 1300 r of 230 kV X-rays. Growth proceeds at a rate about half of normal for 6 days, then more slowly until about 12 days, when growth ceases. The distribution of individual cell sizes broadens during the growth period. Spontaneous loss of these cells from a glass surface may be characterized grossly by an exponential decay function with a 3–5 day half-time; more detailed analysis indicates that the irradiated population consists of two fractions which have half-times for persistence of 1–3 days following a lag of about 2 days (60–80 per cent), and 5–15 days (20–40 per cent), respectively. The more persistent fraction may enter a phase of rapid decay after about 16 days. Methods are described to obtain large-sized pure populations of X-ray induced giant HeLa cells with average volumes 20–40 times normal.
Initiation of DNA synthesis by the avian oncornavirus RNA-directed DNA polymerase: Structural and functional localization of the major species of primer RNA on the oncornavirus genome

Abstract We have both structurally and functionally localized the site on the avian oncornavirus RNA genome at which the major species of primer RNA is bound. Localization of the primer site involved either determining the minimum size class of poly(A)-containing fragments of the viral RNA genome to which radiolabeled primer RNA would anneal, or determining the minimum size class of poly(A)-containing fragments that could be reconstituted as an active template primer complex for the RNA-directed DNA polymerase subsequent to reannealing to unlabeled purified primer RNA. Both approaches indicate that the primer site appears to be very close to (within 10%), or at the 5′ end of the 35 S RNA genome. The implications of these findings on the transcription of the oncornavirus genome in vitro and in vivo are discussed.
Efficient Calculation of Schwarz–Christoffel Transformations for Multiply Connected Domains Using Laurent Series

We discuss recently developed numerics for the Schwarz–Christoffel transformation for unbounded multiply connected domains. The original infinite product representation for the derivative of the mapping function is replaced by a finite factorization where the inner factors satisfy certain boundary conditions derived here. Least squares approximations based on Laurent series are used to satisfy the boundary conditions. This results in a much more efficient method than the original method based on reflections making the accurate mapping of domains of higher connectivity feasible.
Fast method for quantum mechanical molecular dynamics

As the processing power available for scientific computing grows, first-principles Born-Oppenheimer molecular dynamics simulations are becoming increasingly popular for the study of a wide range of problems in materials science, chemistry, and biology. Nevertheless, the computational cost of Born-Oppenheimer molecular dynamics still remains prohibitively large for many potential applications. Here we show how to avoid a major computational bottleneck: the self-consistent-field optimization prior to force calculations. The optimization-free quantum mechanical molecular dynamics method gives trajectories that are almost indistinguishable from an ``exact'' microcanonical Born-Oppenheimer molecular dynamics simulation even when low-prefactor linear scaling sparse matrix algebra is used. Our findings show that the computational gap between classical and quantum mechanical molecular dynamics simulations can be significantly reduced.
Simple amiodarone protocol reduces postoperative atrial fibrillation.

BackgroundIncorporating amiodarone into an existing postoperative atrial fibrillation (AF) prevention pathway may reduce postoperative AF and length of stay (LOS).MethodsFrom July 2002 through Dece...
ACL double bundle linked cortical-aperture tibial fixation: a technical note

Introduction The purpose of this technical note is to describe the tibial fixation characteristics for an all-inside anatomic anterior cruciate ligament (ACL) reconstruction method that links extra-cortical button suspensory and aperture fixation replicating double bundle soft tissue graft function in single femoral and tibial sockets.
Replantation in trauma

Following the first successful digital replant in 1968, replantation after traumatic amputation of the upper limb has become the norm in carefully selected patients. With good communication between the receiving emergency department and microsurgical team, the correct patients can be given appropriate priority and managed smoothly through their complex treatment. This article reviews the indications, initial management, surgical techniques, complications and the ex pected outcomes for upper limb replantation. This will help the nonmicrosurgeon explain to patients who have had an amputation the process of replantation and what they might expect after transfer to the microsurgical team, and it gives an overview of replantation for junior trainee microsurgeons.
Eighteen year's experience with neonatal Hirschsprung's disease treated by endorectal pull-through without colostomy

Abstract Methods : In the past 18 years, the authors have treated 84 patients with Hirschsprung's disease. Of these, 43 patients were under 1 month of age and underwent endorectal pull-through without colostomy. Some have undergone follow-up for as long as 18 years. Results : Thirty-four of these 43 (79%) newborn patients were available for follow-up. Twenty-two were totally continent. The remaining 12 have normal sphincter tone. Of the 41 patients above 1 month of age, 34 (83%) were available for follow-up. Some have undergone follow-up for as long as 18 years. Conclusion : Twenty-two of this latter group (79%) have normal bowel control.
Low Complexity Beamforming Methods for MIMO-OFDM Systems

Multiple-input multiple-output (MIMO) systems can significantly improve the network capacity and the quality of service (QoS). We propose a novel beamforming method for MIMO orthogonal frequency division multiplexing (OFDM) systems in this work. The presented method is based on the Rayleigh Quotient (RQ) of the Fourier transform of the channel matrix. Two RQ analysis algorithms, simple steepest descent and Luo's algorithms, are used to obtain the new beamforming method. It is demonstrated that the proposed method can considerably reduce the complexity and needs only (2K+1)L complex multiplications and 2KL-1 complex additions for a single run, where K and L are the number of antennas at the transmitter and the receiver, respectively. We evaluate the performance of the presented method in AWGN and Rayleigh fading channels. Simulation results show that the new method reduces the bit error rate (BER) significantly while having low computational complexity. It is also shown that the presented method has a very fast convergence rate.
A DIC-based study of in-plane mechanical response and fracture of orthotropic carbon fiber reinforced composite

Abstract The in-plane elastic properties and quasi-static fracture response of an orthotropically woven carbon fiber reinforced composite are investigated using 3D digital image correlation. The elastic properties are determined as a function of fiber orientation, and the effect of fiber angles on the crack extension direction is investigated. The modified maximum hoop stress criterion is used to predict the crack extension angle of the examined material. The predicted angles are in very good agreement with those found experimentally. Optical observations and local strain data from the quasi-static fracture studies reveal that crack initiation occurs well before the maximum far-field load is reached.
Multiple minima in a fluidized reactor—heater system

A minimum cost design problem for a single-reaction fluidized-bed reactor system is analyzed in this paper. The problem's mathematical interest stems from Wilde's statements (1974) that there can be only two types of design to this nonlinear, nonconvex, multimodal problem. It is shown by a direct search procedure that, in fact, there are at least four types of optimal design. Furthermore, the type 3, rather than the type I design, is the global solution to the numerical example considered in Wilde's work, if the required auxiliary cooler cost is excluded.
The finite element method applied to ideal gaseous mixtures

The finite element technique is extended to an ideal gaseous mixture to study diffusion of several gaseous species in a carrier gas under various geometries and flow conditions. This is accomplished by obtaining the finite element analog of the balance of mass for each species, along with the corresponding equations for the balance of mass, momentum and energy for the mixture. Numerical results are obtained for a steady-state, incompressible, isothermal, viscous mixture of two gases for several boundary conditions. Favourable agreement is obtained between the finite element results and analytical solutions.
Measurement of the electron cyclotron energy component of the electron beam of an electron beam ion trap.

The energy component associated with the cyclotron motion of the beam electrons in the Livermore EBIT-II electron beam ion trap was inferred from measurements of the linear polarization of the K-shell x-ray lines emitted from heliumlike ${\mathrm{Mg}}^{10+}$ ions. The average line polarization was found to be reduced by about 20% from its nominal value. From this it was inferred that the electron cyclotron motion accounted for $190\ifmmode\pm\else\textpm\fi{}30 \mathrm{eV}$ of the total electron beam energy. The measured value is in good agreement with the predictions of optical electron beam propagation. It does not agree with the estimates derived from other model assumptions, such as the rigid-rotator model, for determining the size of the energy stored in the electron motion perpendicular to the beam propagation direction.
BACKWARDS BIFURCATIONS AND CATASTROPHE IN SIMPLE MODELS OF FATAL DISEASES

where I is the number of infected people, S is the number of susceptible people, 1 is the total number of people in the population, ! is the transmission rate of the disease, and m is the rate at which individuals leave the infected group. Here IQ means the derivative of I with respect to time, a convention we will use throughout the paper. Equation (1) is applicable to a wide variety of one-group models. Following Castillo-Chavez et al. [3], we allow ! to be a function of 1, allowing a variety of assumptions about mixing. Depending on the type of model, the per-capita removal rate, m, may include the rate of ‘‘background’’ mortality or disease-induced mortality, or transitions to immune, susceptible or quarantined compartments. Note that the number of infectives will increase when S/1'm/! and decrease otherwise. The ratio S/1 gives the proportion of susceptibles in a population, and hence the probability that a given contact of infectious individual is with a susceptible individual, under the assumption of homogeneous mixing. This ratio is at a maximum (generally 1) in a population where the disease is absent, and decreases as the disease begins to invade a population. It is this phenomenon of the disease reducing its own
QT interval prolongation in a patient with LQT2 on levetiracetam.

We report the case of a 24-year old female with a seizure disorder and previously undiagnosed long QT syndrome whose QT interval increased and developed into torsades de pointes after her levetiracetam dose was increased. The patient had been having seizures since age 10. The episodes typically occurred in the early morning and witnesses describe shaking of her entire body, incontinence, and while the patient was not aware of the events at the time when they occurred, she did get tired and confused after the events. She had been started on carbamazepine as a child, with escalating doses as she aged. She presented to the NorthShore epilepsy clinic for the first time after a generalized seizure, and was started on levetiracetam 250 mg twice a day with the plan of increasing the dose over weeks then weaning her carbamazepine (initial random carbamazepine level was 10.1 mg/ml). A brain MRI showed minimal T2 hyperintensities in white matter which were interpreted as non-specific. Her EEG showed intermittent right temporal sharp waves with an electrophysiological maximum at T4 and occasional right temporal polymorphic theta-range slowing suggestive of mild focal cerebral dysfunction. While seizures have not been captured on EEG, the combination of her clinical presentation and focal abnormalities on
New Perspectives on the Settlement-Subsistence System of the Late Woodland Western Basin Tradition, ca. 500–1300 A.D.

Based on joint efforts by the Williams County Historical Society and the Laboratories of Ethnoarchaeology at the University of Toledo, thirty-six new sites, including six Western Basin Tradition ceramic sites, have been documented in the tri-state region of northeastern Indiana, northwestern Ohio, and south-central Michigan. Also, data collected from throughout the Western Lake Erie region since 1984 has necessitated several revisions in the 1984 settlement-subsistence model proposed for the Late Woodland Western Basin Tradition populations, ca. 1000–1300 A.D. (Stothers, Graves, and Redmond, 1984). Key changes involve the relative sizes of functionally different site types that form component parts of a larger settlement system, a lack of formal village life, and a new perspective on seasonal patterns of population coalescence and dispersal.
Irregular Designs for Two-State Systematic with Serial Concatenated Parity Codes

The Irregular Repeat Accumulate (IRA) codes introduced by Jin et al. [1] are structured Low Density Parity Check (LDPC) codes that are known to perform as well as the best unstructured LDPCs. IRAs reach rates that are quite close to capacity on the additive white Gaussian noise (AWGN) channel, can be both encoded and decoded in linear time, are perceived to be low complexity codes, and have been adopted into recent standards. Systematic with Serially Concatenated Parity (S-SCP) codes were recently introduced in [2], [3] as a class of turbo like codes with members that exhibit good performance over a wide range of block sizes, code rates, and target error probabilities. In this paper we introduce irregular designs for Systematic with Serially Concatenated Parity (Ir-S-SCP) codes and show that both for near-capacity and more practical lower-complexity designs, irregular two-state S-SCP codes can be designed to achieve the performance of IRA codes at lower complexity.
A psychoanalytic intervention to fight climate change: Reading This Changes Everything

Although Naomi Klein’s This Changes Everything: Capitalism vs. The Climate presents a careful analysis of why the fight over climate change will have to take on our current system of capitalism, her lack of psychoanalytic knowledge undermines her efforts to promote positive social change. Since she does not take into account the reasons for which people engage in self-destructive acts and fantasies, she is unable to explain why we continue to march towards our own environmental self-destruction. Using the Freudian concepts of masochism, the death drive, and the repetition compulsion, I argue for a psychoanalytic model for social activism against climate change and neoliberal capitalism.
Pyloric obstruction complicating peptic ulcer.

Pyloric obstruction is a well-recognized complication of chronic peptic ulceration of the duodenum, and, when persistent, is an accepted indication for surgical intervention. Despite the frequency with which this complication is encountered, few reports have analyzed in detail the clinical and pathological aspects of obstruction in contrast to hemorrhage and perforation. This report is an analysis of experience with this entity over a 5-year period. Clinical Material Primary definitive operations for duodenal ulcer were performed upon 242 patients on the pavilion service of the New York Hospital during the 5-year period of July 1, 1953, through June 30, 1958. Pyloric obstruction was the indication for operation in 70 patients, or 28.9%. This group was composed of 54 men and 16 women who had an age range from 28 to 78 years. The duration of ulcer symptoms among these patients with pyloric obstruction varied from less than one year in 4
Relative incorporation of the various propionate carbons into fatty acids by lactating rat mammary gland.

Abstract 1. 1. Propionate labeled with 14 C in each of its carbons was incubated with slices prepared from lactating rat mammary glands. In the absence of added glucose, 14 C of [2- 14 C]propionate was more rapidly incorporated into fatty acids than was 14 C of either [1- 14 C]propionate or [3- 14 C]propionate. 2. 2. The addition of glucose to the medium increased fatty acid synthesis from all three carbons of propionate. The 14 C of [2- 14 C]propionate and [3- 14 C]propionate was incorporated at identical rates and exceeded that from [1- 14 C]propionate. 3. 3. Unlabeled acetate, at low concentrations in the presence of glucose, depressed conversion of 14 C of [1- 14 C]propionate into fatty acids. At higher acetate concentrations the conversion from all propionate carbons was depressed. 4. 4. The [ 14 C]fatty acids synthesized from [1- 14 C]-,[2- 14 C]- and [3- 14 C]propionate were subjected to gas-chromatographic analysis, and the presence of both-even-chain [ 14 C]fatty acids and odd-chain [ 14 C]fatty acids was demonstrated. 5. 5. The results suggest that there are at least three pathways for conversion of propionate carbon to fatty acids by lactating rat mammary gland. Direct condensation with malonyl-CoA to form odd-chain fatty acids is by far the most predominant pathway. Glucose stimulated incorporation of propionate carbon into fatty acids by all three pathways equally.
Role of clay minerals in the transportation of iron

Abstract The clay minerals have iron associated with them in several ways: 1. (1) as an essential constituent 2. (2) as a minor constituent within the crystal lattice where it is in isomorphous substitution and 3. (3) as iron oxide on the surface of the mineral platelets. Nontronite, “hydromica,” some chlorites, vermiculite, glauconite and chamosite contain iron as an essential constituent. Kaolinite and halloysite have no site within the lattice for iron, but in certain environments iron oxide (goethite or hematite) is intimately associated as a coating on the micelles. Analyses of clay minerals show that the content of Fe 2 O 3 varies: 29 per cent (nontronite), 7·3 per cent (griffithite), 4.5 per cent (“hydromica”), 5.5 per cent (chlorite), 4 per cent (vermiculite) and 18 per cent (glauconite). The FeO content is: 40 per cent (chamosite), 7.8 per cent (griffithite), 1–2 per cent (“hydromica”), 3 per cent (glauconite) and 2 per cent (chlorite). The iron associated with the clay minerals remains stable in the environment in which the minerals occur, but if either pH or Eh or both are changed the iron may be affected. Change of environment will cause: 1. (1) removal of iron by reduction of Fe 3+ to Fe 2+ ; 2. (2) ion-exchange reactions; 3. (3) instability of the crystal lattice. Experiments using bacterial activity to produce reducing conditions with kaolinite and halloysite coated with iron oxides and with nontronite in which ferric iron is in the octahedral position within the lattice showed that ferric oxide is removed at Eh +0·215 in fresh water and at Eh +0.098 in sea water. Hematite, goethite, and indefinite iron oxides were removed at different rates. Red ferric oxides were changed to black indefinite noncrystalline ferrous sulphide at Eh −0.020 but reverted to ferric oxide under oxidizing conditions. Nontronite turned bright green under reducing conditions and some of the ferrous iron remained within the lattice on a return to oxidizing conditions. Bacterial activity seems to be necessary for maintaining reducing conditions in the environments studied.
Sexual assault and alcohol abuse: a comparison of lesbians and heterosexual women.

Abstract Purpose: To compare and contrast lesbians' and heterosexual women's experiences of sexual assault and to investigate relationships between sexual assault and alcohol abuse. Methods: In-depth interviews were conducted with 63 lesbians and a demographically matched comparison group of 57 heterosexual women. Lesbians' and heterosexual women's experiences of sexual assault, drinking levels, and alcohol-abuse indicators were compared using descriptive statistics. LISREL analysis was used to test the effects of sexual assault on a latent measure of alcohol abuse. Results: Lesbians reported more childhood sexual experiences, were more likely to meet the study definition for childhood sexual abuse (CSA), and were more likely to perceive themselves as having been sexually abused as children. CSA was associated with lifetime alcohol abuse in both lesbian and heterosexual women. However, adult sexual assault (ASA) was associated with alcohol abuse only in heterosexual women. Implications: Sexual assault is a common experience among both lesbians and heterosexual women. Findings emphasize the importance of asking about sexual assault in health histories, and assessing clients for substance abuse and other sequelae of sexual assault.
Catecholamine depletion and accumulation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 1-methyl-4-phenylpyridinium (MPP(+)) in adrenal medullary chromaffin cells.

Abstract Cultures of bovine adrenal medullary chromaffin cells converted 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to 1-methyl-4-phenylpyridinium (MPP + ) by a pargyline-sensitive mechanism. Both MPTP and MPP + accumulated in these cells. Upon subcellular fractionation, distribution of MPP + paralleled that of catecholamines, suggesting storage in chromaffin vesicles. In contrast, MPTP was found in both soluble and particulate fractions, but not in chromaffin vesicles. MPTP produced a rapid depletion of 20–25% of chromaffin cell catecholamines, an action blocked by the nicotinic antagonist d -tubocurarine but not by the monoamine oxidase inhibitor pargyline. This depletion was not mimicked by MPP + . Addition of ⩾ 50 μM MPTP to chromaffin cell cultures caused additional, progressive catecholamine loss from 1 to 6 days of drug exposure that was mimicked by MPP + and not blocked by pargyline or d -tubocurarine. Cultures of bovine adrenal cortical cells also converted MPTP to MPP + and accumulated both of these drugs, but at a slower rate and to a lesser extent than chromaffin cells. Although chromaffin cells form MPP + from MPTP and store MPP + , these studies suggest that catecholamine depletion in these cells results from the actions of MPTP and MPP + which are not stored in chromaffin vesicles. MPTP evokes catecholamine secretion from chromaffin cells via nicotinic acetylcholine receptors. MPTP and free MPP + are also toxic to the cells, probably through blockade of metabolic processes. These findings suggest that cells with a high capacity for MPP + uptake but limited vesicular storage capacity, i.e. sustained high cytoplasmic drug levels, would be susceptible to the toxic actions of this drug.
The binding of thiophenols to bovine carbonic anhydrase

Abstract In contrast to their oxygen analogs, the nitrophenols, 4-nitrothiophenol and 2,4-dinitrothiophenol have been found to be strong inhibitors of bovine carbonic anhydrase. Measurements of the inhibition constants, K I , and the rate constants k 1 for the binding of the thiophenols to the enzyme are consistent with the hypothesis that enzyme-thiophenol complex formation occurs by the reaction of the ionized thiophenol (thiophenolate) with the form of the enzyme in which the water ligand bound to the active site Zn(II) ion is unionized.
A mutant lymphoma cell line with a defectiveThy-1 glycoprotein gene

We characterized a mutant T -cell lymphoma line selected for the inability to express the Thy-1 glycoprotein. This cell line is a member of the D complementation class of Thy-1− somatic cell mutants, and it lacks detectable cell-surface Thy-1.1 glycoprotein and detectable cytoplasmic Thy-1 mRNA. Southern blot analysis using a number of probes isolated from the clonedThy-1.2 gene demonstrated that, in the mutant, one copy of theThy-1 gene is absent from the genome and the other has undergone rearrangement. This rearrangement results from a deletion of the 5′ portion of the gene removing the first two alternate exons and promoters and a portion of the second intron. The deletion breakpoint within the mutantThy-1 gene was localized to within 400 nucleotides by Southern blot analysis. The breakpoint is near two classes of mouse repetitive elements-a mouse B1-family repetitive element and a simple repetitive sequence-suggesting a mechanism of rearrangement leading to the mutation. Southern blot analysis demonstrated that two closely linked molecular markers on chromosome 9 are unaltered, demonstrating that the deletion in this mutant cell line is subchromosomal.
Two-Dimensional Echocardiographic Findings in Atrial Septal Defect

Two-dimensional echocardiographic findings in a group of 24 patients with atrial septal defects were correlated with findings obtained by cardiac catheterization and M-mode echocardiography. The prevalence of mitral prolapse was 95% by two-dimensional echocardiography and 59% by angiography in patients with secundum and sinus venosus atrial septal defects. The majority of the group with echocardiographic prolapse manifested a distinctive pattern of prolapse, with predominant involvement of the anterior mitral leaflet. Thirty-eight percent of the patients in this series manifested paradoxical septal motion by M-mode and/or two-dimensional echocardiography. In the patients with abnormal septal motion, the net systolic anterior movement of the septum was caused by an exaggerated systolic anterior movement of the main body of the left ventricle. The atrial septal defect could be visualized with confidence by two-dimensional echocardiography only in the two patients with ostium primum atrial septal defects. Cleft anterior mitral leaflets were also clearly demonstrated in these two patients.
Use of an oxidase electrode to determine factors affecting the in vitro production of hydrogen peroxide by ehrlich cells and 1-chloro-2,4-dinitrobenzene

Abstract A hydrogen peroxide (H2O2) electrode was used to continuously monitor H2O2 concentrations in vitro in a system designed to determine some of the factors which influence cellular H2O2 production and reduction. 1-Chloro-2,4-dinitrobenzene (CDNB), a clinical and analytical agent, was found to alter electron transport in Ehrlich ascites tumor cells (EATC), causing formation of H2O2. H2O2 accumulation in the cell suspension began after an initial lag period required for glutathione (GSH) depletion. N-Ethylmaleiraide (NEM), which removes thiols, shortened the lag period but did not alter the rate at which H2O2 accumulated. H2O2 accumulation was influenced by glucose and drug concentrations and glucose was important in determining the total amount of H2O2 that eventually accumulated. The metabolic reduction of exogenously added H2O2 in the absence of CDNB was stimulated by glucose, unaffected by azide (a catalase inhibitor), and inhibited by NEM. The data show that glutathione peroxidase is chiefly responsible for inactivating intracellularly produced H2O2 and that at least three mechanisms may operate to remove glutathione in CDNB-treated cells. The findings imply that artificially low levels of GSH may be found when CDNB is used as an analytical reagent in whole cells and that topical use of CDNB may pose a genetic health hazard.
Signal-to-noise and radiation exposure considerations in conventional and diffraction x-ray microscopy

Using a signal-to-noise ratio estimation based on correlations between multiple simulated images, we compare the dose efficiency of two soft x-ray imaging systems: incoherent brightfield imaging using zone plate optics in a transmission x-ray microscope (TXM), and x-ray diffraction microscopy (XDM) where an image is reconstructed from the far-field coherent diffraction pattern. In XDM one must computationally phase weak diffraction signals; in TXM one suffers signal losses due to the finite numerical aperture and efficiency of the optics. In simulations with objects representing isolated cells such as yeast, we find that XDM has the potential for delivering equivalent resolution images using fewer photons. This can be an important advantage for studying radiation-sensitive biological and soft matter specimens.
Structure-Function Analysis of the Reactive Site in the First Kunitz-type Domain of Human Tissue Factor Pathway Inhibitor-2

Human tissue factor pathway inhibitor-2 (TFPI-2) is a Kunitz-type proteinase inhibitor that regulates a variety of serine proteinases involved in coagulation and fibrinolysis through their non-productive interaction with a P1 residue (Arg-24) in its first Kunitz-type domain (KD1). Previous kinetic studies revealed that TFPI-2 was a more effective inhibitor of plasmin than several other serine proteinases, but the molecular basis for this specificity was unclear. In this study, we employed molecular modeling and mutagenesis strategies to produce several variants of human TFPI-2 KD1 in an effort to identify interactive site residues other than the P1 Arg that contribute significantly to its inhibitory activity and specificity. Molecular modeling of KD1 based on the crystal structure of bovine pancreatic trypsin inhibitor revealed that KD1 formed a more energetically favorable complex with plasmin versus trypsin and/or the factor VIIa-tissue factor complex primarily due to strong ionic interactions between Asp-19 (P6) and Arg residues in plasmin (Arg-644, Arg-719, and Arg-767), Arg-24 (P1) with Asp-735 in plasmin, and Arg-29 (P5′) with Glu-606 in plasmin. In addition, Leu-26 through Leu-28 (P2′–P4′) in KD1 formed strong van der Waals contact with a hydrophobic cluster in plasmin (Phe-583, Met-585, and Phe-587). Mutagenesis of Asp-19, Tyr-20, Arg-24, Arg-29, and Leu-26 in KD1 resulted in substantial reductions in plasmin inhibitory activity relative to wild-type KD1, but the Asp-19 and Tyr-20 mutations revealed the importance of these residues in the specific inhibition of plasmin. In addition to the reactive site residues in the P6–P5′ region of KD1, mutation of a highly conserved Phe at the P18′ position revealed the importance of this residue in the inhibition of serine proteinases by KD1. Thus, together with the P1 residue, the nature of other residues flanking the P1 residue, particularly at P6 and P5′, strongly influences the inhibitory activity and specificity of human TFPI-2.
The out of plane shear problem for an infinite sheet with a staggered array of pairs of cracks

Abstract A triple series technique is used to find closed form expressions for the Mode III stress intensity factors of a staggered array of pairs of cracks in an infinite elastic solid.
How I got into linguistics, and what I got out of it

When I first went to college (it was in 1944, while the war was still on), I spent a fair amount of time trying to figure out what I wanted to do, and even more time trying to guess if I could do it. Some people say I'm a quick study, but it took me a good fifteen years to work up the answers. If you are in your sophomore year and don't have your own solutions yet, I'd encourage you to reflect that it doesn't always pay to be too fast in replying to important problems. The kids who sit at their desks with their hands in the air often don't know what the question is all about.
Median unbiased estimation of coefficient variance in a time-varying parameter model

Abstract This article considers inference about the variance of coefficients in time-varying parameter models with stationary regressors. The Gaussian maximum likelihood estimator (MLE) has a large point mass at 0. We thus develop asymptotically median unbiased estimators and asymptotically valid confidence intervals by inverting quantile functions of regression-based parameter stability test statistics, computed under the constant-parameter null. These estimators have good asymptotic relative efficiencies for small to moderate amounts of parameter variability. We apply these results to an unobserved components model of trend growth in postwar U.S. per capita gross domestic product. The MLE implies that there has been no change in the trend growth rate, whereas the upper range of the median-unbiased point estimates imply that the annual trend growth rate has fallen by 0.9% per annum since the 1950s.
Assessment and Accommodation Issues under the No Child Left behind Act and the Individuals with Disabilities Education Improvement Act: Information for IEP Teams.

Including students with disabilities in the new standards and accountability systems is one of the key challenges facing school districts around the nation. In this article, the authors first address the evolving assessment and accommodations requirements of both the No Child Left Behind Act of 2001 (NCLB) and the Individuals with Disabilities Education Improvement Act of 2004 (IDEIA), with specific emphasis on the interrelationships between education curriculum standards, participation options, and accommodation decisions. Second, using findings from earlier studies, they discuss the decision-making practices of school personnel with regard to participation and accommodations practices for students with high-incidence disabilities who participate in state assessments with or without accommodations. Finally, they suggest areas for future research, including those that may arise with the emergence of alternate assessments based upon modified achievement standards and from the increased monitoring of accomm...
Nutrient Losses, Quality, and Feeding Values of Wilted and Direct-cut Orchardgrass Stored in Bunker and Tower Silos

Summary First-cutting orchardgrass was preserved as: 1. Wilted silage stored in a tower silo. 2. Direct-cut, sodium metabisulfite–treated silage, stored in a tower silo. 3. Direct-cut sodium metabisulfite–treated silage, stored in a bunker silo. These silages were prepared in each of two successive years and all silages were sealed with weighted plastic covers. The silages were compared on the basis of storage losses, storage temperatures, chemical quality, feeding trials, and digestion trials. An expression of silage feeding value which combines dry matter intake rate and TDN content has been proposed. Tower storage of wilted forage and bunker storage of the direct-cut forage were about equally efficient in preserving feed nutrients. Tower storage of direct-cut forage was consistently less efficient, primarily because of higher seepage losses. All silages were of good chemical quality and of about equally high feeding value. The wilted silage, however, contained more butyric acid in both years and was consumed by dairy cattle in significantly greater amounts one year. The bunker silo, as used in this experiment, was a more suitable storage structure for direct-cut orchardgrass than a tower silo. However, when forages were stored in tower silos, the wilting method was generally more satisfactory than direct-cutting combined with sodium metabisulfite treatment.
The microwave spectrum of argon-phosphorus trifluoride

Several van der Waals complexes with a high atom percentage of fluorine have been studied by high-resolution techniques. Examples include BF3-N2 [ 11, HCFs bonded to an acid or ammonia [ 2,3], COF2-Ar [ 41, ClF-Ar [ 5 1, and a number of HF complexes [ 61. Most of the systems are linear or symmetric tops. Usually the fluorine atoms are distant from the second species and do not appear to directly interact with it. Ar-COF2 is an exception; it is an asymmetric top (of necessity) with the Ar located above the CF2 triangle. We report here the microwave spectrum of the Ar-PFX complex which is also an asymmetric top. In this complex, the fluorine is closer than phosphorus to the argon atom.
Improvement cm precision of sedimentation-equilibrium experiments with an on-line absorption scanner

Abstract An on-line computerized optical absorption scanner for the analytical ultracentrifuae has been developed and tested. It makes direct use of the instantaneous photomultiplier output, which is digitized and averaged by the computer. It incorporates a stepping motor to drive the photomultiplier, two analog-to-digital converters, and a device which monitors precessional movement of the rotor. The scanner has been employed chiefly in sedimentation equilibrium experiments, and techniques have been devised to correct for the adverse effects of inhomogeneities of apparent absorbance which arise from the cell windows. Correction for rotor movements which occur during the scan is also possible. The completed apparatus is a successful one, and provides a significant improvement in precision, speed and convenience over the commercially available scanners. The limitations on precision inherent in the present design are examined, and it is concluded that the combined effects of window inhomogencities and rotor movement lead to uncertainty of the measured absorbance which is unlikely to be reduced below ± 0.001 A.
Characterization of polymer brushes in capillaries

The synthesis of various polymer brush coatings were performed in 0.075 mm i.d. fused silica capillary tubing by atom transfer radical polymerization (ATRP). Although characterization of polymer coatings inside of capillaries is extremely difficult, we will show how fluorescence spectroscopy can be used as a technique to verify that covalently attached polymer brushes are present. Capillary rise measurements show the Zisman critical surface energy (γ c) changes as the polymer coatings are changed from either hydrophilic or hydrophobic. The hydrophilic and hydrophobic nature of polymers leads to selective flow behavior in micro-capillaries that will allow passive flow control. © 2007 Elsevier B.V. All rights reserved.
Progress in coupling models of human and coastal landscape change

Humans are increasingly altering the Earth's surface, and affecting processes that shape and reshape landscapes. In many cases, humans are reacting to landscape-change processes that represent natural hazards. Thus, the landscape is reacting to humans who are reacting to the landscape. When the timescales for landscape change are comparable to those of human dynamics, human and 'natural' components of developed environments are dynamically coupled-necessitating coupling models of human and physical/biological processes to study either environmental change or human responses. Here we focus on a case study coupling models of coastal economics and physical coastline change. In this modeling, coastline change results from patterns of wave-driven sediment transport and sea-level rise, and shoreline stabilization decisions are based on the benefits of wide beaches (capitalized into property values) balanced against the costs of stabilization. This interdisciplinary modeling highlights points that may apply to other coupled human/natural systems. First, climate change, by accelerating the rates of landscape change, tends to strengthen the coupling with human dynamics. In our case study, both increasing sea-level-rise rates and changing storm patterns tend to increase shoreline change rates, which can induce more vigorous shoreline stabilization efforts. However, property values can fall dramatically as erosion rates and stabilization costs rise, which can also lead to the abandonment of expensive stabilization methods as shoreline change rates increase. Second, socio-economic change can also strengthen the human/landscape coupling. Changing costs of shoreline stabilization can alter stabilization decisions, which in turn alters patterns of coastline change. The coupled modeling illuminates the long-range effects of localized shoreline stabilization efforts; communities arrayed along a coastline are unwittingly affecting each other's erosion rates, and therefore each other's economies. Our coupled modeling experiments show that spatial distributions of property values and erosion rates can jointly affect economic outcomes, resource allocation between communities, and patterns of shoreline change. These findings raise questions about coastal management strategies, and efficient and equitable allocation of scarce resources among coastal communities.
Effects of Corner Frequency on Bandwidth and Resonance Amplitude in Designing PZT Thin-Film Actuators: An Experimental Demonstration

In the last decade, Lead Zirconate Titanate Oxide (PZT) thin-film actuators have received increasing attention because of their high frequency bandwidth, large actuation strength, fast response, and small size. The PZT film thickness is usually less than several microns as opposed to hundreds of microns for bulk PZT patches that are commercially available. As a result, PZT thin-film actuators pose unique vibration issues that do not appear in actuators with bulk PZT. Two major issues affecting actuator performance are the frequency bandwidth and the resonance amplitude. As an electromechanical device, a PZT thin-film actuator’s bandwidth and resonance amplitude depend not only on the lowest natural frequency ωn of the actuator’s mechanical structure but also on the corner frequency ωc of the actuator’s RC-circuit. For PZT thin-film actuators, the small film thickness implies large film capacitance C and small ωc . When the size of the actuator decreases, frequency ωn increases dramatically. As a result, improper design of PZT thin-film actuators could lead to ωc ≪ ωn substantially reducing the actuator bandwidth and the resonance amplitude. This paper is to demonstrate this phenomenon through calibrated experiments. In the experiments, frequency response functions of a fixed-fixed silicon beam with a 1-μm thick PZT film are measured through use of a laser Doppler vibrometer and a spectrum analyzer. The silicon beam has multiple electrodes with a wide range of resistance R and corner frequency ωc . The experimental results confirm that the actuator bandwidth and resonance amplitude are substantially reduced when ωc ≪ ωn .Copyright © 2005 by ASME