cssi/SciSciGPT-SciSciNet huggingface dataset:
A large-deformation, finite-element study of chondrodiatasis in the canine distal femoral epiphyseal plate

Abstract A large-deformation, finite-element analysis was conducted to model stress fields around the developing growth plate as a first approach to comprehend the clinical application of traction for limb lengthening procedures. The model chosen was a cross section through the distal femoral growth plate of a 14-week-old dog. The chosen section passed through two of the conformational bends (mammillary processes) formed by the natural convolutions of the physis. Three different loading conditions were applied to the distal femoral epiphyseal model. The model also examined the effects of different values of Young's modulus of the growth-plate cartilage. The cortical bone in all cases, experienced the highest stresses. In the growth plate, the highest principal stresses occurred where the physis intersects cortical bone. There were localized stresses that were higher than those that caused fracture in a rabbit model [Guse et al., J. Orthop. Res. 7, 667–673 (1989)]. Results also indicated the following: a small tilt of 0.1 in loading application increases the maximum principal stresses and the von Mises stresses in certain regions of the growth plate by about 8%; the shearing streses in the growth plate are sensitive to Young's modulus of the growth plate; and traction pins that do not grip the cancellous bone in the epiphysis will increase the regions of high principal stress in the growth plate.
An adaptation of the lattice gas to the water problem. II. Second-order approximation

The adaptation of the lattice-gas model to embody features possessed by water is further explored. On the basis of Martin's functional derivative formulation of Ising problems, a perturbation scheme is developed which allows calculation of the free energy to any desired order in the interaction potential at fixed density. The free energy correct to second order in the interaction strength is utilized here for calculation of other thermodynamic properties of the model. With reasonable choices of values of the interaction parameters these thermodynamic properties of the model can be brought into agreement with those of real water.
The resource-based relative value scale.

THE Health Care Financing Administration (HCFA) introduced on January 1,1992, a fee schedule 1 for physician payment under Medicare based on the resource-based relative value scale (RBRVS) of Hsiao et al. 2 In 1988, the then—chief administrator of HCFA outlined in detail why RBRVS was inappropriate for reform of the Medicare payment system 3 (a skepticism that is said to persist within HCFA today). Congress nevertheless mandated the use of the RBRVS by HCFA. I criticized the RBRVS 4 for, among other things, the fact that the scale attempts to establish relative values among specialties based on the putative value of different types of work without considering that some specialties are known to work many more hours per week than others. Fairness in designing a payment system requires that hourly reimbursement rates be computed. See also p 3313. The Commentaries of Hsiao et al 5 and Radecki et al 6
The role of residual stresses in the mechanical performance of case carburized steels

Residual stresses in case carburized steels stem from two major sources, both of which are associated with the (rapid) cooling of the steels from elevated temperatures. The first source is the more rapid cooling rate of the surface of the body, as compared with the rate of the interior. The second is the time lag in the transformation of the austenite on cooling between the high carbon and low carbon portions of the carburized body. The as-carburized residual stress intensities and states are altered to varying degrees dur-ing the course of the tests used to measure the mechanical properties. The significant changes take place not only as the result of the strain of the measurement test itself, but also because of the transformation of any austenite retained in the case of the carburized part, and because of stresses developed within the part by virtue of the rheological inter-actions which occur within the part since it is, in essence, a composite material. The resultant observed mechanical performance of the carburized body is the summation of the intrinsic mechanical properties of the material itself, and the effects of the residual stresses as-carburized, and as-altered by the above phenomena.
Responses to GABAA receptor activation are altered in NTS neurons isolated from chronic hypoxic rats

The inhibitory amino acid GABA is released within the nucleus of the solitary tract (NTS) during hypoxia and modulates the respiratory response to hypoxia. To determine if responses of NTS neurons to activation of GABA(A) receptors are altered following exposure to chronic hypoxia, GABA(A) receptor-evoked whole cell currents were measured in enzymatically dispersed NTS neurons from normoxic and chronic hypoxic rats. Chronic hypoxic rats were exposed to 10% O(2) for 9-12 days. Membrane capacitance was the same in neurons from normoxic (6.9+/-0.5 pF, n=16) and hypoxic (6.3+/-0.5 pF, n=15) rats. The EC(50) for peak GABA-evoked current density was significantly greater in neurons from hypoxic (21.7+/-2.2 microM) compared to normoxic rats (12.2+/-0.9 microM) (p<0.001). Peak and 5-s adapted GABA currents evoked by 1, 3 and 10 microM were greater in neurons from normoxic compared to hypoxic rats (p<0.05) whereas peak and 5-s adapted responses to 30 and 100 microM GABA were not different comparing normoxic to hypoxic rats. Desensitization of GABA(A)-evoked currents was observed at concentrations greater than 3 microM and, measured as the ratio of the current 5 s after the onset of 100 microM GABA application to the peak GABA current, was the same in neurons from normoxic (0.37+/-0.03) and hypoxic rats (0.33+/-0.04). Reduced sensitivity to GABA(A) receptor-evoked inhibition in chronic hypoxia could influence chemoreceptor afferent integration by NTS neurons.
Interest rate expectations and interest parity

Abstract This paper examines an hypothesis for explaining divergences from interest parity that is based on interest rate expectations. If interest rates are expected to rise significantly within the arbitrage oppurtunity implies riskless profit. Waiting in ths way has been noted in the historical literature, seems to make sense theoritically (if portfolio adjusment cost in the capital market outweigh any costs of being out of long term equilibrium), and explains a significant portion of US-UK interest parity divergences using onshore assets in a recent floating preiod.
Youth Recovery Contexts: The Incremental Effects of 12‐Step Attendance and Involvement on Adolescent Outpatient Outcomes

Background A major barrier to youth recovery is finding suitable sobriety-supportive social contexts. National studies reveal most adolescent addiction treatment programs link youths to community 12-step fellowships to help meet this challenge, but little is known empirically regarding the extent to which adolescents attend and benefit from 12-step meetings or whether they derive additional gains from active involvement in prescribed 12-step activities (e.g., contact with a sponsor and other fellowship members). Greater knowledge in this area would enhance the efficiency of clinical continuing care recommendations.
Isolation and characterization of the monounsaturated long chain fatty acids ofMycobacterium tuberculosis

The positions of double bond in the monounsaturated C15−C32 fatty acids ofMycobacterium tuberculosis H37Ra were established by gas chromatography/mass spectrometry of the ozonized esters and their pyrrolidide derivatives. The monounsaturated C15−C21 fatty acids had the double bond primarily at the Δ9 position while the monounsaturated longer chain fatty acids (C22−C32) had the double bond in several positions. Many of the latter acids, especially the odd-numbered series, were very complex isomeric mixtures. Quantitation showed the most abundant even-numbered long chain fatty acid isomers to be as follow: C22, Δ4; C24, Δ5; C26, Δ7 and Δ9; C28, Δ9; C30, Δ11 and Δ13; C32, Δ13 and Δ15.
Accessibility of Cysteines Within the NBD Interface in a CFTR Channel

Opening and closing of a CFTR channel is accompanied by ATP-driven formation and hydrolysis-triggered disruption of a head-to-tail NBD1-NBD2 heterodimer where composite interfacial sites, between the Walker motifs of one NBD and the LSGGQ-like (ABC signature) sequence of the other, each enclose an ATP molecule. Only the “NBD2” composite site (containing NBD2 Walker motifs) is catalytically competent. The ATP-bound tight NBD1-NBD2 heterodimer is linked to the open-channel state, but the disposition of the NBDs in the closed-channel state of CFTR, in the absence of ATP or after its hydrolysis, remains unknown. To address this, we assess accessibility to various size MTS reagents of single interfacial target cysteines introduced into the ABC signature sequence of the competent site (at NDB1 position S549), or of the dead site (at NBD2 position S1347), or at mid-interface positions S605 of NBD1 or A1374 of NBD2, in full-length cys-depleted CFTR-C(832-1458)S,expressed in Xenopus oocytes and examined in excised patches. Cysteines at all four positions were readily accessible to MTSET in closed channels in the absence of ATP. For channels opening and closing in 3 mM ATP, the reaction rate depended on MTSET concentration and was ∼105 M−1s−1 at 5 μM at position 549, and was similarly rapid at corresponding position 1347. In closed channels without ATP, cysteines at 549, 605, 1347, and 1374 were all also readily accessible to MTS reagents of increasing size, e.g., MTS-biotin, MTS-THAE (trihexylammonium-ethyl) and MTS-verapamil, up to ∼11Ax16Ax10A, suggesting substantial separation between NBD1 and NBD2, throughout the NBD interface, in closed CFTR channels. (Supported by NIH DK51767).
Visually lossless data compression technique for real-time frame/pushbroom space imagers

A visually lossless data compression technique is currently being developed for space science applications under the requirement of high-speed push-broom scanning. The technique is also applicable to frame based imaging data. The algorithm first performs a block transform of either a hybrid of modulated lapped transform (MLT) with discrete cosine transform (DCT), or a 2-dimensional MLT. The transform is followed by a bit-plane encoding; this results in an embedded bit string with exact desirable compression rate specified by the user. The approach requires no unique look-up table to maximize its performance and is error-resilient in that error propagation is contained within a few scan lines for push- broom applications. The compression scheme performs well on a suite of test images acquired from spacecraft instruments. Flight qualified hardware implementations are in development; a functional chip set is expected by the end of 2001. The chip set is being designed to compress data in excess of 20 Msamples/sec and support quantization from 2 to 16 bits.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Raman scattering in the depletion region of GaAs

Abstract We have obtained spectra for the LO phonon mode by Raman scattering associated with surface quantization of the hole states in the depletion layer of highly doped n -type GaAs samples. When semi-transparent metal contacts are employed, the zone-center LO peak shifts to higher frequency due to plasmon-phonon interaction. The observed effects are not sensitive to the types of metal. The presence of the plasmon mode is thought to be due to the steady-state carrier injection from the incident laser light. The position of the peak is used to estimate the surface recombination rate of the excited electron-hole pairs.
The cyclically repetitive firing sequencess of identifiedDrosophila flight motoneurons

The flight motoneurons ofDrosophila melanogaster apparently are driven by a common input, yet each is phase-locked to a different time in a repeating cycle. The salient features of the pattern which are described in this paper are the following: 1. The motoneurons to fibers within each single muscle interact and maintain a pattern of activity which is independent of the patterns in the other muscles. 2. The four ventral motor units in each dorsal longitudinal muscle (DLM) generate impulses preferentially in either of two cyclically repeating sequences,-c, e, d, f- or -c, f, d, e-. 3. The two dorsal DLM fibers appear to be innervated by a single motoneuron, 45a/b. This dorsal motor unit fires slightly faster than the four ventral units and thus progressively advances through their sequence, forming an epicycle of activity. 4. The dorsal ventral muscles (DVM) 48 and 46 each have two motor units which usually fire alternately. The remaining DVM, 47, has three motor units which also fire in a repeating cycle, but with frequent changes of position in the sequence. 5. This precise sequencing of motoneuron activity probably occurs also in a variety of other Diptera.
A biological assay for ribonuclease with sub-millimicrogram sensitivity.

SummaryAn ultra-sensitive method of assay for ribonuclease (RNase) has been devised using a biologically active ribonucleic acid (RNA) as its substrate. Infectious RNA isolated from foot-and-mouth disease virus was exposed to suitable dilutions of RNase, and the resulting loss in RNA infectivity was measured by plaque assay in calf-kidney cultures. Concentrations of enzyme as low as 0.1 mμg per ml were readily detected. The RNase level in sera from man and several animal species was determined by this method. Most sera contained 0.02 to 0.1 μg/ml of RNase, but guinea pig serum had a 20- to 30-fold higher content of this enzyme.
Fabric stability in oblique convergence and divergence

Abstract Forward modeling of transpression–transtension, assuming homogeneous strain and a direct relationship between finite strain axes and foliation–lineation in tectonites, investigates fields of stability of foliation and lineation orientations in oblique convergence and divergence. Vertical foliation–horizontal lineation (VF–HL) develop for angles of convergence–divergence between 0 and 20°. With increasing finite strain, this narrow window of stability is further reduced; lineation switches to vertical in transpression and foliation switches to horizontal in transtension. If a shear zone contains VF–HL, it either developed as a zone very close to pure wrenching, or recorded low finite strain. The stability of VF–HL at high strain and higher angles of convergence is enhanced by lateral extrusion of material along transpression zones. VF–HL may be stabilized in magmatic bodies that progressively intrude transtension zones, if the wrench component of deformation partitions within them. Alternatively, if these bodies are dike-like, cool fast, and do not record large deformation, they take up the extension component of transtension through anisotropic volume addition, leaving a larger component of wrench deformation in the country rocks; this effect stabilizes VF–HL effectively at low strain, but only marginally so at high strain.
Spatial agreement between two land‐cover data sets stratified by agricultural eco‐regions

Two of the most widely used land‐cover data sets for the United States are the National Land‐Cover Data (NLCD) at 30‐m resolution and the Global Land‐Cover Characteristics (GLCC) at 1‐km nominal resolution. Both data sets were produced around 1992 and expected to provide similar land‐cover information. This study investigated the spatial distribution of NLCD within major GLCC classes at 1‐km unit over a total of 11 agricultural‐related eco‐regions across the continental United States. Our results exhibited that data agreement or relationship between the GLCC and NLCD was higher for the eco‐regions located in the corn belt plains with homogeneous or less complicated land‐cover distributions. The GLCC cropland primarily corresponded to NLCD row crops, pasture/hay and small grains, and was occasionally related to NLCD forest, grassland and shrubland in the remaining eco‐regions due to high land‐cover diversity. The unique GLCC classes of woody savanna and savanna were mainly related to the NLCD orchard and g...
Computing and controlling compliance of a robotic hand

The authors express the compliance of the grasp of a robotic hand as a function of grasp geometry, contact conditions between the fingers and the grasped object, and mechanical properties of the fingers. It is argued that the effects of structural compliance and small changes in the grasp geometry should be included in the computation. Factors are then examined that can lead a grasp to become unstable, independently of whether it satisfies force closure. Finally, the authors examine the reverse problem of how to specify servo gains at the joints of a robotic hand so as to achieve, as nearly as possible, a desired overall grasp compliance. It is shown that coupling between the joints of different fingers is useful in this context. >
The Road to Treating Smoldering Multiple Myeloma

The management of smoldering multiple myeloma (SMM) has been a challenge to clinicians, ever since the condition was first characterized in 1980. While the risk of progression to symptomatic myeloma is greater for SMM (10% per year) compared to MGUS (1% per year), several SMM patients remain asymptomatic for years without evidence of disease progression. Early clinical trials focusing on early treatment of SMM have been equivocal with no clear benefit. However, the last decade has seen a greater understanding of the pathogenesis of plasma cell disorders, including SMM, and development of better therapeutics. A recent randomized trial has provided evidence of clinical benefit with early treatment of high-risk SMM. In this review, we summarize issues related to the early treatment of SMM including risk stratification and possible outcomes with therapy initiation. In the context of reviewing recent clinical trial data supporting early treatment, we define challenges faced by clinicians and provide future directions to the road to treating SMM.
Characterizing the Emerging Population of Prescription Opioid Abusers

Despite an alarming recent increase in prescription opioid abuse, the characteristics of prescription opioid abusers remain largely unknown. In this study, the demographic and drug use characteristics of 75 methadone patients (36 prescription opioid and 39 heroin users) were compared using a retrospective chart review. Prescription opioid abusers exhibited a profile of characteristics that may predict favorable treatment response, including less severe opioid use and IV drug use, and greater social stability compared to primary heroin abusers. Despite the limitations inherent in this retrospective chart review, this study provides initial evidence that prescription opioid abusers may have a number of characteristics that predict favorable treatment response. This new information may inform and assist current efforts to develop efficacious treatments for prescription opioid abuse.
Longitudinal diffusion tensor imaging in Huntington's Disease.

Serial diffusion tensor imaging scans were collected at baseline and 1 year follow-up to investigate the neurodegenerative profile of white matter (WM) in seven individuals with the Huntington's Disease (HD) gene mutation and seven control subjects matched on age and gender. In the HD subjects, but not controls, a significant reduction of fractional anisotropy (FA), a measure of WM integrity, between baseline and follow-up was evident throughout the brain. In addition, a DTI scalar associated with the stability of axons, axial diffusivity, showed significant longitudinal decreases from year 1 to year 2 in HD subjects, declines that overlapped to greater degree with FA discrepancies than longitudinal increases in radial diffusivity, a DTI variable sensitive to demylinization. These preliminary results provide the first longitudinal DTI evidence of WM degeneration in HD and support the notion that FA abnormalities in HD may be a result of axonal injury or withdrawal. These results suggest that longitudinal FA changes may serve as a neuropathological biomarker in HD.
A new temporal interpolation method for high-frequency vector wind fields

A new technique for the time interpolation of the forcing fields that recovers the movement of propagating features is introduced and applied to vector wind fields. The method involves the decomposition of the fields into their complex empirical orthogonal functions, and the interpolation of the temporal functions for the significant modes. The technique is tested using atmospheric model vector wind fields sampled at coarse temporal resolution to demonstrate the recovery of the wind fields at the intermediate times. The technique is also applied to a gridded vector wind product from satellite scatterometer data.
The role of glutamate in physical dependence on opioids.

Abstract The present review will evaluate the interactions between κ-opioid receptors and glutamate within the locus coeruleus (LC) during the development of opioid dependence and on expression of withdrawal from dependence on opioids. Hyperactivity of noradrenergic neurons in the LC has been proposed to play a critical role in the physiological and behavioral responses that comprise opioid withdrawal. Several studies indicate that the excitatory amino acid system, in particular, glutamate and its receptors, participate in both the withdrawal-associated increase in LC neuronal activity and the expression of opioid withdrawal behaviors. Most studies on opioid dependence have focused on the prototypical opioid morphine, which produces its physical dependence through agonist actions at the μ-opioid receptor. Butorphanol (Stadol®), which exhibits a markedly different profile of opioid receptor activity than does morphine, produces its physical dependence primarily through actions at the κ-opioid receptor. Studies from our laboratories using a rodent model in which butorphanol administration induces dependence indicate further that the κ-opioid receptor is an important regulator of glutamate release within the LC. Glutamate exerts actions within the LC that mediate expression of behavioral symptoms of butorphanol withdrawal.
Factor XSt. Louis II IDENTIFICATION OF A GLYCINE SUBSTITUTION AT RESIDUE 7 AND CHARACTERIZATION OF THE RECOMBINANT PROTEIN

A molecular defect in factor X (fX) results from a point mutation that causes glycine substitution for γ-carboxylated glutamic acid at position 7. The variant (fXSt. Louis II) and wild type (fXWT) proteins were produced in a mammalian expression system and characterized. fXSt. Louis II has
Block copolyetheramides. II. Synthesis and morphology of nylon‐6 based block copolyetheramides

A novel preparation method of nylon 6-based bloch copolyetheramides via two stage reaction was developed which avoided the problem of phase separation. The reaction mixture remained homogeneous at both stages and a high molecular weight polymer was obtained. Microphase separation was observed. The domain size of nylon 6 segment was found to be about 20 nm and some domains aggregated to clusters of about 100 nm.
Life Tables of the White Pine Weevil, Pissodes strobi , in Central Maine

Life tables (1977–1980) are presented for three generations of the white pine weevil, Pissodes strobi (Peck) (Coleoptera: Curculionidae), a pest insect of eastern white pine, Pinus strobus L. Typically, female weevils oviposited ca. 140 eggs per terminal leader of a host tree in the spring; however, only 1 progeny adult survived to the following spring. Average generation survival (SG = 0.008) and total generation mortality (K = 2.08) reflected observed small increases in weevil infestation each year. Key factor analysis suggested that larval, pupal, and winter submortalities were the major influences on population change. Submortality factors were: (1) egg infertility, (2) pitch-drowning, (3) larval instraspecific competition, (4) natural enemy predation and parasitism, (5) nonemergent brood adults, (6) unknown cause(s) of death, and (7) effect of climatic conditions on overwintering adults.
Rob: Children's tacit use of peer ostracism to control aggressive behavior

This is a case study of the way in which a group of children tacitly used ostracism to control and suppress the aggressive behavior of one member of the group. The events reported occurred spontaneously during observational fieldwork on patterns of authoritative behavior in a preschool peer group. This case raises issues regarding the origins and characteristics of patterns of societal norms and of norm enforcement. Particularly significant is the suggestion that ostracism does not require a moralistic basis and does not have to result from any formal societal or collective decision.
Si(113) hydrogen desorption kinetics: A temperature programmed desorption study

Hydrogen desorption kinetics from Si(1 1 3) surfaces were investigated using D2 temperature programmed desorption (TPD). For this purpose, clean Si(1 1 3)3×2 wafers were exposed to atomic deuterium at 200°C for times sufficient to provide D coverages θD ranging up to saturation, θD,sat. Corresponding low-energy electron diffraction patterns transform from 3×2 to 3×1-D to 1×1 with increasing θD. TPD spectra from Si(1 1 3) surfaces with θD=θD,sat consist of a first-order desorption feature (β1) centered at 515°C and a second-order desorption peak (β2) at 405°C. β2 is assigned to D2 desorption, with an activation energy of 2.16 eV, from a dideuteride surface phase while β1 is due to desorption from monodeuteride. The β1 peak consists of two components: β1,t which arises due to first order, as a result of π-bond induced ordering, D2 desorption from tetramers and β1,ad which is due to second-order D2 desorption from adatoms and second-layer surface atoms. Both β1 components have activation energies of 2.58 eV. Following monodeuteride desorption, the clean Si(1 1 3) surface again exhibits a 3×2 reconstruction. The TPD results are explained based upon previously proposed models for the Si(1 1 3)3×2 reconstructed surface.
Transport and Photolysis of Pentachlorophenol in Soils Subject to Evaporating Water

Pentachlorophenol (PCP) was applied to loamy sand and sandy clay loam soils to determine the effect of upward evaporative flux on the rates of photolytic loss. Subirrigated soil columns were irradiated by ultraviolet lamps or sunlight to measure relative rates of photolytic loss under differing soil moisture regimes. Photolysis was initially rapid in loamy sand soil under near-saturated flow conditions, with up to 55% more lost in light-exposed treatments in 14 d as compared to dark controls. Rates of transport were slower in sandy clay loam soil, reflecting a soil sorption distribution coefficient of 10 mL/g, as compared to 0.4 mL/g in the loamy sand. Despite slower upward movement, similar amounts of photodegradation of PCP had occurred in the sandy clay loam soil after 14 d. Dropping the water table to the 15 or 25 cm depth resulted in unsaturated flow and increased losses to volatilization, with a much lower relative contribution of photodegradation over the course of the experiments. Up to 77% was lost from the loamy sand soil dark treatments during the 14-day period, due to volatilization and irreversible sorption. Processes that translocate PCP into the sunlit surface zone under near-saturated soil moisture conditions can be expected to enhance rates of photolytic loss while minimizing volatilization.
University Oversight of Professors’ Teaching Activities: A Professor’s Academic Freedom Does not Mean Freedom From Institutional Regulation

This article reviews federal case law that address a college instructor’s right to academic freedom over classroom activities. This review shows that the federal courts have defined a college instructor’s academic freedom rights narrowly in terms of the instructor’s classroom activities. Institutions have a great deal of latitude to regulate an instructor’s classroom speech, grading practices, and general manner of teaching a particular college-level course.
Highly sensitive detection of exocytotic dopamine release using a gold-nanoparticle-network microelectrode.

Here we report a new type of microelectrode sensor for single-cell exocytotic dopamine release. The new microsensor is built by forming a gold-nanoparticle (AuNP) network on a carbon fiber microelectrode. First a gold surface is obtained on a carbon fiber microdisk electrode by partially etching away the carbon followed by electrochemical deposition of gold into the pore. The gold surface is chemically functionalized with a sol−gel silicate network derived from (3-mercaptopropyl)trimethoxysilane (MPTS). A AuNP network is formed by immobilizing Au nanoparticles onto the thiol groups in the sol−gel silicate network. The AuNP-network microelectrode has been characterized by scanning electron microscopy (SEM) and steady-state voltammetry. The AuNP-network microelectrode has been used for amperometric detection of exocytotic dopamine secretion from individual pheochromocytoma (PC12) cells. The results show significant differences in the kinetic peak parameters including shorter rise time, decay time, and half-...
Intratumoral aromatase model: The effects of letrozole (CGS 20267)

An intratumoral aromatase model in the ovariectomized nude mouse was developed which simulated the hormone responsive postmenopausal breast cancer patient. MCF-7, human breast cancer cells transfected with the aromatase gene, inoculated into ovariectomized nude mice are able to synthesize sufficient estrogens to enhance cell proliferation and the development of tumors. These tumors are responsive to both antiestrogens and aromatase inhibitors. However, letrozole was found to be more effective than tamoxifen and caused tumor regression, a result not previously noted in nude mice with endocrine treatments. When the aromatase inhibitors were combined with tamoxifen, tumor growth was suppressed to about the same extent as treatment with the aromatase inhibitors alone. Thus, there was no additive or synergistic effects of combining tamoxifen with aromatase inhibitors. These results suggest that letrozole has the potential to be more effective than tamoxifen for achieving greater reduction in estrogenic effects on tumors and uterus in postmenopausal breast cancer patients. In addition, sequential treatment with these agents is likely to be more beneficial to the patient in terms of longer response to treatment.
Chemical characterization of hemoglobin-Mexico and hemoglobin-Chiapas.

Two new hemoglobins found during surveys of several Indian populations in Mexico have been chemically characterized. The first, HbMexico, was found in two unrelated individuals and was shown to be α254Gln→Glu β2. The second, HbChiapas, was found to have the structure α2114Pro→Argβ2.
Probing the local structure of crystalline ZITO: In2-2xSnxZnxO3 (x≤0.4)

The local structure of In{sub 2}O{sub 3} cosubstituted with Zn and Sn (In{sub 2-2x}Sn{sub x}Zn{sub x}O{sub 3}, x {le} 0.4 or ZITO) was determined by extended X-ray absorption fine structure (EXAFS) for x = 0.1, 0.2, 0.3 and 0.4. The host bixbyite In{sub 2}O{sub 3} structure is maintained up to the enhanced substitution limit (x = 0.4). The EXAFS spectra are consistent with random substitution of In by the smaller Zn and Sn cations, a result that is consistent with the 'good-to-excellent' conductivities reported for ZITO.
Ground effects for VHF/HF antennas on helicopter airframes

In this paper, the finite element method (FEM) is used to predict the space and surface wave radiation patterns of VHF/HF antennas mounted on a helicopter in the presence of a lossy ground. The equivalent sources of the radiation system are obtained by solving an FEM problem in conjunction with an absorbing boundary condition (ABC) or an impedance boundary condition (IBC). From the equivalent sources, the total radiated field is calculated using the equivalence principle and superposition; the original problem is converted into a set of properly combined Hertzian dipoles referred to as the Sommerfeld problem. Instead of evaluating the Sommerfeld integral rigorously, Norton's approximation is used to improve the overall computational efficiency. The validation of this method is accomplished in two steps: first, the FEM is compared with the finite-difference time-domain method (FDTD) in the absence of a lossy ground; second, the Hertzian dipole problem is solved in the presence of a lossy ground and the results are compared with analytic solutions. Finally, this technique is extended to analyze an antenna on a helicopter above a lossy ground.
Analysis and efficient implementation of fuzzy logic control algorithms

Fuzzy logic is presently used to synthesize single layer nonlinear control systems in an increasing range of application areas. The proper role for fuzzy logic is within the framework of a hierarchically structured control system that may incorporate conventional control strategies. The paper focuses on integration of these notions within an analytically tractable framework whereby certain fundamental system theoretic properties such as stability and robustness to modeling uncertainty can at least in principle be verified. The proposed approach is based on large scale systems theory and incorporates nonlinear singular perturbation in an analytical study of hierarchically structured control systems as well as the notion of Kalman filter based optimal system identification. Theorems regarding the behavior of such systems are presented and their implications are discussed.
Demographic Differences Among Children in Judging and Experiencing Specific Stressful Life Events

The study evaluated differences in the judged upsettingness and frequency of occurrence of 22 stressful life events among 503 fourth- to sixth-grade, urban and suburban school children. Children first judged the upsettingness of each event for age peers. Next, they indicated which events they had experienced personally and rated their personal level of upset with each event experienced. Except for the items, "school suspension" and "being sent to the principal," on which boys exceeded girls, there were no sex differences in events experienced. Girls, however, judged stressful events to be markedly more upsetting than boys, both cognitively and experientially. Urban children experienced more stressful events than suburban children and judged them, experientially, to be more upsetting.
Expression of CB2 cannabinoid receptor mRNA in adult rat retina

To date, two cannabinoid receptors, CB1 and CB2, have been cloned. The CB1 receptor has been found in a variety of tissues, particularly in the brain. CB2 receptor mRNA is mainly expressed in the immune system, though one group has found it in mouse cerebellum. Previous immunostaining studies in our lab demonstrated the presence of CB1 receptors in the retina though little evidence exists for the presence of CB2. The putative endogenous ligand for CB2 has been found in retina, however, suggesting that further study of CB2 in retina is warranted. Because glutamate is toxic to retinal ganglion cells in glaucoma and activation of CB2 receptors may be able to protect neurons from glutamate-induced death, we examined the expression of CB2 mRNA in adult rat retina in order to better understand possible neuroprotective mechanisms relevant to glaucoma. Using in situ hybridization, we demonstrated that CB2 cannabinoid receptor messenger RNA was clearly expressed in the adult rat retina, including the somas of retinal ganglion cells. Antisense cRNA probe detected strong signals in the retinal ganglion cell layer, the inner nuclear layer, and the inner segments of photoreceptor cells. Using reverse transcription polymerase chain reaction (RT-PCR) in both rat and mouse tissue, we obtained an RT-PCR product with the same sequence as that reported for CB2 in the GenBank database, thus confirming the presence of CB2 mRNA in retina. The presence of CB2 in retina provides new evidence for the presence of CB2 in the central nervous system (CNS) and an excellent model for its study.
Assessment of Regional-Distance Location Calibration Using a Multiple-Event Location Algorithm

Abstract We test the use of a multiple-event seismic location method to improve epicenter accuracy estimates. Regional arrival-time observations of 74 Nevada Test Site explosions with known locations comprise the test data set. We investigate epicenter accuracy as a function of the number of events in the multiple-event system that are constrained at the known hypocenter (calibration), the effect of distance between calibration and unconstrained events, and the use of velocity models with varying travel-time prediction accuracy. Further, we test the utility of using a posteriori travel-time residuals to assess location and travel-time prediction accuracy. We find that constraining one event at the known hypocenter reduces epicenter error for all other events by 58% on average compared to locations produced without constraining events. The incremental improvement in epicenter accuracy rapidly diminishes as more hypocenters are constrained, and incremental location improvement is minimal when the number of constrained hypocenters exceeds 10. Events closest to a constrained event exhibit small location bias. Distinct epicenter bias occurs when the distance between the calibration event and the relocated event is greater than a few tens of kilometers. Last, we confirm that metrics based on a posteriori travel-time residuals are poor indicators of both epicenter accuracy and velocity model-based travel-time prediction accuracy.
Uptake and metabolism of glutamate at non-synaptic regions of crayfish central nerve fibers: implications for axon-glia signaling.

In crayfish and squid giant nerve fibers, glutamate appears to be an axon-glia signaling agent. We have investigated glutamate transport and metabolism by crayfish central nerve fibers in order to identify possible mechanisms by which glutamate could subserve this non-synaptic signaling function. Accumulation of radiolabeled l-glutamate by desheathed cephalothoracic nerve bundles was temperature and Na 1 dependent, linear with time for at least 8 h and saturable at about 0.5-1 mM l-glutamate. Most accumulated radiotracer was associated with the periaxonal glial sheath and remained as glutamate. Compounds known to block glutamate transport in invertebrate peripheral nerves or mammalian brain slices or cell cultures were also effective on crayfish central nerve fibers. Tissue radiotracer levels were only 3% of control levels when 1 mM p-chloromercuriphenylsulfonate was present, and 13%, 20%, 26%, 38% and 42% of control levels, respectively, when l-cysteate, l-cysteine sulfinate, l-aspartate, d- aspartate or dl-threo-b-hydroxyaspartate was present. l-Glutamine, GABA, N-methyl-dl-aspartate, a-aminoadipate and d-gluta- mate were without inhibitory effect on tissue tracer accumulation. Radiolabeled d-aspartate was an equivalent non-metabolized substitute for radiolabeled l-glutamate. d-Aspartate, p-chloromercuriphenylsulfonate and GABA had comparable effects on isolated medial giant nerve fibers. These studies indicate that l-glutamate is taken up primarily by the periaxonal glia of crayfish central nerve fibers by a low- affinity, saturable, Na 1 -dependent transport system and is retained by the fibers primarily in that form. Our results suggest that the glia are not only the target of the glutamate signal released from non-synaptic regions of the crayfish medial giant axon during high- frequency stimulation, but that they are also the primary site of its inactivation. q 2000 IBRO. Published by Elsevier Science Ltd.
Fertility and viability at the Sod locus in Drosophila melanogaster: non-additive and asymmetric selection.

Experiments were designed to test in Drosophila melanogaster the effect of mating type at the Sod locus on fertility and viability. The experiments show that fertility is neither additive (or multiplicative) nor symmetric, i.e. that the fertility of a mating type cannot be predicted from the average fertility of the two genotypes involved in the mating. There is no significant male x female interaction with respect or progeny viability; but the interaction is significant for productivity, i.e. when fertility and viability are jointly taken into account. There is overdominance with respect to female fertility, but not with respect to male fertility or to viability. There also is alloprocoptic selection with respect to fertility and with respect to productivity, i.e. mating between like homozygotes are less fertile and productive than matings between dissimilar homozygotes. Selection at the Sod locus yields stable polymorphic equilibria, with the frequency of the F allele predicted at P = 0.641 or 0.695, respectively for low and high larval density.
The impact of provider volume on mortality after intracranial tumor resection.

OBJECTIVE: Policies of regionalization and selective referral for a number of high-risk surgical procedures are being explored and implemented as a result of significant variation in postoperative mortality between high- and low-volume providers. The effect of provider volume on outcomes after intracranial tumor resection is unknown and warrants investigation. METHODS: By use of the Nationwide Inpatient Sample for 1996 and 1997, patients (older than 19 yr) who had a diagnosis of a malignant central nervous system neoplasm and underwent craniotomy or craniectomy were included. Hospital volume and surgeon volume were categorized by quartiles (very low, low, high, or very high volume). Unadjusted and case mix-adjusted analyses were performed with regard to postoperative in-hospital mortality. RESULTS: The crude in-hospital mortality was 2.8% for a total of 7547 patients. The mean patient age was 55.8 years (66.5% <65; 33.5% ≥65). Mortality for very low- to very high-volume hospitals was as follows: 3.8, 3.2, 2.4, and 1.8% (P < 0.001). Mortality for very low- to very high-volume surgeons was as follows: 4.1, 3.9, 3.1, and 1.4% (P = 0.003). Predictors of mortality in a logistic regression model were emergent admission (odds ratio [OR], 2.97; 95% confidence interval [CI], 2.02-4.38; P < 0.001), and age 65 years or greater (OR, 1.63; 95% CI, 1.16-2.30; P = 0.005). The risk of mortality was reduced for very high-volume hospitals (OR, 0.58; 95% CI, 0.35-0.97; P = 0.038) and very high-volume surgeons (OR, 0.42; 95% Cl, 0.22-0.84; P = 0.012). CONCLUSION: Higher-volume providers have superior outcomes after surgical resection of malignant intracranial tumors. This reduction was maintained despite adjustment for case mix. As the regionalization of high-risk surgery moves forward, it is important for neurosurgeons to maintain leadership roles in the development of specialty-specific data collection and health policy initiatives that improve and reduce variation in outcomes.
Determination of unique microbial volatile organic compounds produced by five Aspergillus species commonly found in problem buildings.

This study identified unique microbial volatile organic compounds (UMVOCs) produced by five Aspergillus species (A. fumigatus, A. versicolor, A. sydowi, A. flavus, and A. niger) cultivated on malt extract agar and gypsum board. The hypothesis was that UMVOCs can be used to predict the presence of Aspergillus species. During the cultivation humidified air was continually supplied and evenly distributed through each of the culture flasks. Volatile metabolites were collected using Tenax TA tubes on Days 8, 16, and 30 after inoculation. The volatile metabolites were determined by gas chromatography/mass spectroscopy after thermal desorption. Nine compounds recognized as UMVOCs—3-methyl-1-butanol; 2-methyl-1-propanol; terpineol; 2-heptanone; 1-octen-3-ol; dimethyl disulfide; 2-hexanone; 3-octanone; and 2-pentylfuran—were found on the cultures in detectable amounts. The first two compounds were detected at the highest frequency when combining both media. The first four compounds were found to be the dominant UM...
MISER: an integrated three layer gridless channel router and compacter

Presented is a new gridless, three-layer channel router (MISER) based on an integrated approach to routing and compaction in VLSI design. MISER partitions the input net-list into several sub-net-lists called levels and forms a level-graph. This level-graph is used to guide the routing and compaction process. Compaction is done immediately after each level is routed. Experimental results show that the algorithm usually performs 5-10 % better than existing three-layer channel routing algorithms. >
A review of methods for futility stopping based on conditional power

Conditional power (CP) is the probability that the final study result will be statistically significant, given the data observed thus far and a specific assumption about the pattern of the data to be observed in the remainder of the study, such as assuming the original design effect, or the effect estimated from the current data, or under the null hypothesis. In many clinical trials, a CP computation at a pre-specified point in the study, such as mid-way, is used as the basis for early termination for futility when there is little evidence of a beneficial effect. Brownian motion can be used to describe the distribution of the interim Z-test value, the corresponding B-value, and the CP values under a specific assumption about the future data. A stopping boundary on the CP value specifies an equivalent boundary on the B-value from which the probability of stopping for futility can then be computed based on the planned study design (sample size and duration) and the assumed true effect size. This yields expressions for the total type I and II error probabilities. As the probability of stopping increases, the probability of a type I error alpha decreases from the nominal desired level (e.g. 0.05) while the probability of a type II error beta increases from the level specified in the study design. Thus a stopping boundary on the B-value can be determined such that the inflation in type II error probability is controlled at a desired level. An iterative procedure is also described that determines a stopping boundary on the B-value and a final test critical Z-value with specified type I and II error probabilities. The implementation in conjunction with a group sequential analysis for effectiveness is also described.
Vascular trauma as a result of therapeutic procedures for the treatment of malignancy

Twenty-two iatrogenic vascular injuries caused by resection of tumors with local recurrences or adjuvant chemotherapy were treated over a 42-month period in 11 female and 8 male patients with cancer (58% had documented metastases). Sixteen of 22 vascular injuries were caused by intraarterial administration of chemotherapy (8 emboli; 8 direct catheter trauma), and six were caused by resection of tumors with local invasion. The injuries were extremity ischemia (15 extremities in 13 patients), pseudoaneurysm (4), expanding hematoma (3 injuries in 2 patients). Twenty-two surgical repairs included bypass of severely damaged arteries in five, embolectomy in five, interposition grafts in three, pseudoaneurysm resection and primary repair in three, primary repair of three vascular injuries, and one patch angioplasty. Leg amputation was required in two patients. Seventeen of 19 patients had successful vascular repairs with resolution of preoperative indications for vascular repair without intraoperative or postoperative deaths. Long term follow-up (mean, 17 months) showed no recurrence of vascular problems; however, two patients died of metastatic cancer at 6 and 24 weeks after vascular repair. This study supports an aggressive approach to the management of vascular injuries caused by therapeutic interventions for malignancy despite the presence of metastatic disease.