cssi/SciSciGPT-SciSciNet huggingface dataset:
Cocaine use and HIV risk behavior in methadone maintenance patients

This study examined sexual and drug use behavior in 247 methadone maintenance patients, to explore the association of cocaine use with human immunodeficiency virus (HIV) risk behavior. In univariate analyses, cocaine use was positively associated with any drug injection, number of injections, and sexual intercourse without condoms. These relationships remained significant after controlling for other drug use and demographic factors. Heroin use also contributed to injection-related risk. We conclude that cocaine use represents a continued source of risk for exposure to HIV in this population, and that more aggressive efforts are warranted to reduce illicit drug use, particularly of heroin and cocaine, in methadone patients.
Nonenzymatic Sugar Production from Biomass Using Biomass-Derived γ-Valerolactone

Widespread production of biomass-derived fuels and chemicals will require cost-effective processes for breaking down cellulose and hemicellulose into their constituent sugars. Here, we report laboratory-scale production of soluble carbohydrates from corn stover, hardwood, and softwood at high yields (70 to 90%) in a solvent mixture of biomass-derived γ-valerolactone (GVL), water, and dilute acid (0.05 weight percent H2SO4). GVL promotes thermocatalytic saccharification through complete solubilization of the biomass, including the lignin fraction. The carbohydrates can be recovered and concentrated (up to 127 grams per liter) by extraction from GVL into an aqueous phase by addition of NaCl or liquid CO2. This strategy is well suited for catalytic upgrading to furans or fermentative upgrading to ethanol at high titers and near theoretical yield. We estimate through preliminary techno-economic modeling that the overall process could be cost-competitive for ethanol production, with biomass pretreatment followed by enzymatic hydrolysis.
Estimating Smoking-Attributable Mortality in the United States

Tobacco use is the largest single cause of premature death in the developed world. Two methods of estimating the number of deaths attributable to smoking use mortality from lung cancer as an indicator of the damage from smoking. We reestimate the coefficients of one of these, the Preston/Glei/Wilmoth model, using recent data from U.S. states. We calculate smoking-attributable fractions for the 50 states and the United States as a whole in 2004, and estimate the contribution of smoking to the high adult mortality of the southern states. We estimate that 21% of deaths among men and 17% among women were attributable to smoking in 2004. Across states, attributable fractions range from 11% to 30% among men and from 7% to 23% among women. Smoking-related mortality also explains as much as 60% of the mortality disadvantage of southern states compared with other regions. At the national level, our estimates are in close agreement with those of the Centers for Disease Control and Prevention and Preston/Glei/Wilmoth, particularly for men, although we find greater variability by state than does CDC. We suggest that our coefficients are suitable for calculating smoking-attributable mortality in contexts with relatively mature epidemics of cigarette smoking.
Molecular basis of inherited medium-chain acyl-CoA dehydrogenase deficiency causing sudden child death

Deficiency of medium-chain acyl-CoA dehydrogenase (MCAD) is an important cause of sudden death in children. The majority of surviving individuals with MCAD deficiency studied to date are homozygous for a single point mutation at bp 985 of the MCAD mRNA (A985G). We have now identified a four-base-pair deletion in exon 11 of one allele of the MCAD gene in an American child who died of MCAD deficiency. The deletion mutation results in a frameshift and premature termination codon in the mutant MCAD mRNA. The second mutant allele contained the common point mutation A985G, and thus the proband was a compound heterozygote. Protein immunoblot analysis of the child's liver proteins revealed that the mutant MCAD proteins were barely detectable. Allele-specific oligonucleotide hybridization analysis performed on amplified exon 11 of the child's MCAD gene clearly identified both mutations. MCAD RFLP analysis of the patient's DNA revealed heterozygosity at the Taq I MCAD RFLP site, thus, the two mutations are associated with different haplotypes. Therefore, we have identified a new mutation in the MCAD gene and have developed a nucleic-acid-based screening approach which allows the post mortem identification of MCAD deficiency.
Flux quantization and angular momentum in non-Abelian gauge field theories

We study a Yang-Mills field, with gauge group generators L/sub a/ (a = 1, . . . ,n), coupled to self-interacting source fields through a gauge coupling constant e. The following results are obtained: (a) The total angular momentum, defined as Poincare group generators, is the free-field angular momentum plus (1/2..pi..) Q/sub a/Phi-arrow-right/sub a/, where Q/sub a/ is the total charge and Phi/sup k//sub a/ is the total flux of ..delta.. x A/sub a/ in the x/sup k/ direction. (b) There is a choice of )L/sub a/) such that the flux matrix Phi-arrow-right equivalent Phi-arrow-right/sub a/L/sub a/ obeys the quantization condition ((e/2..pi..) Phi/sup 1/,(e/2..pi..) Phi/sup 2/) = (ie/2..pi..) Phi/sup 3/. (c) (e/2..pi..) Phi-arrow-right generates gauge transformations that are equivalent to spatial rotations of asymptotic Higgs fields. (d) For any solution in which (e/2..pi..) Phi-arrow-right not-equal 0, the gauge field is a monopole field with pole strength g = 1/e.
On-line pulse control for structural and mechanical systems

This paper studies the feasibility of using open-loop adaptive on-line pulse control for limiting the response of large linear multidegree of freedom systems subjected to general dynamic loading environments. Pulses of short durations are used to control the system when the system response exceeds a given threshold level. The pulse magnitudes are obtained in closed form, leading to large computational efficiencies when compared with optimal control theoretic methods. The technique is illustrated for a structural system subjected to earthquake-like base excitations.
Multiple-Valued Minimization for PLA Optimization

This paper describes both a heuristic algorithm, Espresso-MV, and an exact algorithm, Espresso-EXACT, for minimization of multiple-valued input, binary-valued output logic functions. Minimization of these functions is an important step in the optimization of programmable logic arrays (PLA's). In particular, the problems of two-level multiple-output minimization, minimization of PLA's with input decoders and solutions to the input encoding problem rely on efficient solutions to the multiple-valued minimization problem. Results are presented for a large class of PLA's taken from actual chip designs. These results show that the heuristic algorithm Espresso-MV comes very close to producing optimum solutions for most of the examples. Also, results from a chip design in progress at Berkeley show how important multiple-valued minimization can be for PLA optimization.
A Snapshot of Electronic Journals, August 1999

Abstract In response to scientific journal price increases, universities and academic libraries are taking action to encourage the introduction of lower cost electronic journals that will compete with the established commercial publishers. Additionally, universities are banding together to purchase electronic journal database subscriptions on more favorable terms than could have been obtained independently. It has recently been suggested at a meeting of university provosts that the ease with which articles can be posted on the Internet makes it possible to revise the entire mechanism of academic publishing. For example, scholarly societies could create certification boards to peer-review articles submitted for publication. Upon certification, the authors could post the articles marked with a “seal of approval” on their Websites. While this proposal raises additional issues to be resolved before it could ever be implemented, the potential for a diminished role of traditional print journals is worthy of fur...
Steady-State Testing with Saw-Tooth Waves

The saw-tooth voltage wave has two main advantages over the square voltage wave in the testing of electrical networks. These are (1) the saw-tooth wave tests the response of the network not only to odd harmonic voltages but to even harmonics as well and (2) from the response to the saw-tooth voltage wave, the response to any other voltage of the same period may be obtained without the use of Fourier series. The square wave is also shown to be a special case of the saw-tooth wave. The response curves of several circuits to the saw-tooth wave are also obtained, and several experimental results are included.
Chemoautotrophic sulfur-oxidizing bacteria from the Black Sea

In contrast to earlier attempts, we were able to isolate nine strains of obligately chemoautolithotropic, sulfur-oxidizing bacteria from three offshore stations in the western basin of the Black Sea (R.V. Knorr Cruise 134-9, Black Sea leg 2). The isolates grew with doubling times averaging 1.3 h over a pH range of 6.5–9.0 in artificial sea water containing thiosulfate. They also oxidized hydrogen sulfide, elemental sulfur and tetrathionate. Although acid producing, growth of the isolates was neutrophilic (optimum pH 7.5). Nitrate or manganese and iron oxides were not utilized as alternate electron acceptors. If acetate was present, not more than 10% of the incorporated carbon was mixotrophically obtained from the organic source. With a DNA base composition range of 37–40 mol % G+C, the new isolates appear to belong to the genus Thiomicrospira (36–44 mol % G+C) rather than Thiobacillus (55–68mol % G+C). Experimental studies on the potential sulfide oxidation by the new isolates under in situ conditions suggest that, above a certain density of active cells (ca 104 ml−1 ), biological sulfide oxidation appears to be able to compete successfully with its spontaneous chemical oxidation.
Organizational characteristics of solid-organ donor hospitals and nondonor hospitals.

Context—Efforts to increase organ donation include serious attempts in hospital settings, where unrealized donation potential exists. Research on hospital donation must include understanding organizational as well as patient-specific influences on the donation process.Objective—To identify organizational characteristics that distinguish hospitals producing organ donations from those that do not, and to estimate the number of nondonor hospitals with donor potential.Design—Data from the American Hospital Association's 1992 annual survey of hospitals were matched to Organ Procurement and Transplantation Network information from the United Network for Organ Sharing regarding the number of solidorgan donors in 1992. Hospitals with donation capability were identified, based on bed size and factors necessary to produce successful donor maintenance and organ recovery. Based on statistical analyses, organizational characteristics distinguishing donor hospitals from nondonor hospitals were identified. We also compa...
Bone Marrow Histoplasmosis Associated with Acute Lymphocytic Leukemia

Summary A patient with longstanding acute leukemia under chemotherapy developed a spiking fever of unknown origin. Chest X-rays demonstrated pulmonary involvement. Blood cultures were positive for gram negative bacteria. Specific antibiotic therapy which included Pentamidine for a surmissed pneumocystis infection did not relieve the symptoms. A routine bone marrow examination disclosed Histoplasma Capsulatum which was later confirmed by a positive bone marrow culture. Specific immunological tests were repeatedly negative. Serial bone marrow examinations and cultures are suggested as the means to search for etiologic agents in febrile patients undergoing chemotherapy.
Thermochemistry of the biochemical reaction: { pyrophosphate(aq) + H2O(l) = 2 phosphate(aq)}

Abstract Calorimetric enthalpies of reaction have been measured for the overall biochemical reaction {pyrophosphate(aq) + H 2 O( l ) = 2 phosphate ( aq )} . The reaction was catalyzed by alkaline phosphatase and, to simplify the thermochemistry, was carried out in the absence of Mg 2 + (aq). Measurements were performed with phosphate buffer ( pH = 7.19 and 7.94), PIPES buffer ( pH = 7.13 ), and HEPES buffer ( pH = 7.86 ). The results of these measurements were analyzed by using an equilibrium model. These calculations lead to the standard molar enthalpy change Δ r H m o = − (17.3 ± 0.6) kJ · mol − 1 (temperature T = 298.15 K and ionic strength I = 0) for the reference reaction {HP 2 O 7 3 − (aq) + H 2 O(l) = 2HPO 4 2 − (aq) + H + (aq)} . Values of the apparent equilibrium constant K ′ for the overall biochemical reaction from the literature were also analyzed by using the equilibrium model in order to obtain what is believed to be a reliable value for the equilibrium constant K = 4.7 · 10 − 4 for the reference reaction. The values of K and Δ r H m o for the reference reaction have been used together with values from the CODATA tables to calculate standard molar formation properties for the pyrophosphate species.
Visualization of ordered genomic RNA and localization of transcriptional complexes in rotavirus

In double-stranded-RNA (dsRNA) viruses found in animals, bacteria and yeast, the genome is transcribed within the structurally intact core of the virion with extraordinary efficiency. The structural organization of the genome and the enzymes involved in the transcription inside any of these viruses, critical for understanding this process, is not known. Here we report what we believe is the first three-dimensional characterization of the viral genome and the transcription complex in a prototypical dsRNA virus. Rotavirus is a large (diameter 1,000 A) icosahedral virus composed of three capsid protein layers and 11 dsRNA segments. It is the most important cause of gastroenteritis in children, accounting for over a million deaths annually. We show that viral dsRNA forms a dodecahedral structure in which the RNA double helices, interacting closely with the inner capsid layer, are packed around the enzyme complex located at the icosahedral 5-fold axes. The ordered RNA accounts for about 4,500 out of a total 18,525 base pairs in the genome, the largest amount of icosahedrally ordered RNA observed in any virus structure to date. We propose that the observed organization of the dsRNA is conducive for an orchestrated movement of the RNA relative to the enzyme complex during transcription.
In Situ Observations of Kelvin-Helmholtz Waves along a Frontal Inversion

Abstract An unusual set of observations of amplifying Kelvin-Helmholtz waves along a New England coastal front inversion is presented and compared to linear theory. The waves were observed by instrumented aircraft traversing the coastal front at various levels and measuring temperature and horizontal and vertical wind components at one-second intervals. The most prominent group of waves had amplitudes in the neighborhood of 100 m, comparable to the total depth of the inversion, and wavelengths near 1.7 km. Spectral analysis of data from an aircraft pass located just above the inversion indicates that Kelvin-Helmholtz billows of 1−2-km wavelength were present over a distance of at least 25 km. Numerical solution of the Taylor-Goldstein equation for observed and specified basic-state vertical profiles confirms that instability of the Kelvin-Helmholtz type is the dominant mode of instability. The wavelength of the most unstable mode is found to be strongly sensitive to the relative thicknesses of the shear a...
Survival of Tn5 mutant bean rhizobia in desert soils : phenotypic expression of Tn5 under moisture stress

Abstract The survival and phenotypic expression of a transposon Tn5 mutant of bean rhizobia ( Rhizobium leguminosarum bv. phaseoli ) and the corresponding wildtype under increasing moisture stress conditions was studied in two Sonoran Desert soil types. Survival studies in sterile and nonsterile soil showed that both biotic and abiotic factors influenced the survival of the mutant and the wild type. In the silty clay loam, the Tn5 mutant population averaged ca 10 5 cfu g −1 soil even at a moisture content of 2% (corresponding to a soil water potential of P 5 cfu g −1 soil at a moisture content of 1% (
Kappa opioid agonists produce anxiolytic-like behavior on the elevated plus-maze.

The selectivek agonist U-50,488H was evaluated on the elevated plus-maze test of anxiety. U-50,488H was administered intraperitoneally to male Sprague-Dawley rats 20 min before testing, first in an open field apparatus, then followed immediately on the elevated plus-maze. No significant change in spontaneous locomotor activity was measured in the open field apparatus, suggesting that U-50,488H was devoid of sedative effects in the dose range tested (0.1–1000 µg/kg, IP). Doses between 10 and 1000 µg/kg produced significant increases in elevated plus-maze behavior that were consistent with anxiolytic actions for U-50,488H. These anxiolytic-like effects were antagonized by naloxone (2.0 mg/kg, IP), suggesting an opioid receptor site of action. In addition, we tested thek1-selective U-50,488H-derivative, U-69,593 (100 µg/kg, IP), which was also shown to mimic the anxiolytic-like effects produced by U-50,488H. These results suggest that low doses of the selectivek1 agonists U-50,488H and U-69,593 are endowed with anxiolytic properties in rodents and that thek opioid system may be involved in the behavioral response to anxiety.
Intracortical Bone Remodeling Variation Shows Strong Genetic Effects

Intracortical microstructure influences crack propagation and arrest within bone cortex. Genetic variation in intracortical remodeling may contribute to mechanical integrity and, therefore, fracture risk. Our aim was to determine the degree to which normal population-level variation in intracortical microstructure is due to genetic variation. We examined right femurs from 101 baboons (74 females, 27 males; aged 7–33 years) from a single, extended pedigree to determine osteon number, osteon area (On.Ar), haversian canal area, osteon population density, percent osteonal bone (%On.B), wall thickness (W.Th), and cortical porosity (Ct.Po). Through evaluation of the covariance in intracortical properties between pairs of relatives, we quantified the contribution of additive genetic effects (heritability [h 2]) to variation in these traits using a variance decomposition approach. Significant age and sex effects account for 9 % (Ct.Po) to 21 % (W.Th) of intracortical microstructural variation. After accounting for age and sex, significant genetic effects are evident for On.Ar (h 2 = 0.79, p = 0.002), %On.B (h 2 = 0.82, p = 0.003), and W.Th (h 2 = 0.61, p = 0.013), indicating that 61–82 % of the residual variation (after accounting for age and sex effects) is due to additive genetic effects. This corresponds to 48–75 % of the total phenotypic variance. Our results demonstrate that normal, population-level variation in cortical microstructure is significantly influenced by genes. As a critical mediator of crack behavior in bone cortex, intracortical microstructural variation provides another mechanism through which genetic variation may affect fracture risk.
Interaction of fibrinogen-binding tetrapeptides with fibrin oligomers and fine fibrin clots.

The polymerization of fibrin, at pH 8.5 and ionic strength 0.45, and under conditions where the action of thrombin on fibrinogen was the rate-determining step, was interrupted by inactivating thrombin with p-nitrophenyl-p′-guanidinobenzoate (NPGB). Addition of the tetrapeptide Gly-Pro-Arg-Pro (GPRP) partially dissociated the fibrin oligomers as shown by subsequent ligation with Factor XIIIa and calcium ion followed by denaturation and gel electrophoresis; polyacrylamide gel electrophoresis with reduction showed a decrease in the proportion of γ-γ ligation compared with controls untreated by GPRP, and agarose gel electrophoresis showed a shift in the distribution of oligomer sizes. The dissociation was accomplished within 15 min and its extent was consistent with establishment of an equilibrium in which two molecules of GPRP react to sever an oligomer. When GPRP was introduced into fine unligated fibrin clots by diffusion, there was some dissociation as shown by differences in the degree of γ-γ ligation after treatment by Factor XIIIa; but the action of GPRP was much slower and less complete than on soluble oligomers. However, even a small amount of dissociation affected the mechanical properties of fine clots profoundly. The shear modulus (measured 25 s after application of stress) decreased progressively with increasing concentration of GPRP introduced by diffusion. The rate of shear creep under constant stress and the proportion of irrecoverable deformation also increased enormously. If the steadystate creep rate is interpreted in terms of an effective viscosity, the latter is decreased by up to three orders of magnitude by the presence of GPRP. In terms of transient network theories of viscoelasticity, the average lifetime of a network strand is greatly diminished. However, the total density of strands remains constant during creep and creep recovery as shown by constancy of the differential modulus or compliance. Removal of GPRP by diffusion only partially restores the original shear modulus and creep behavior of the original clot. Some limited data on the effect of the tetrapeptide Gly-His-Arg-Pro are also reported.
Test comparisons among stress-affected, stress-resilient, and nonclassified fourth- through sixth-grade urban children.

Test performance of three groups of urban 4th- through 6th-graders – highly stressed children with stress-resilient (SR) or stress-affected (SA) adjustment outcomes, and demographically matched nonclassified (NC) peers – from 2-year cohorts, was compared on measures used both to select SRs and SAs and to expand the definitional net for childhood resilience. On adjustment-selection and verification measures, SRs exceeded NCs and NCs exceeded SAs. On the criterion test measures, both SRs and NCs exceeded SAs.
Influence of caterpillar-feeding damage on the foraging behavior of the paper wasp Mischocyttarus flavitarsis (Hymenoptera: Vespidae)

Experiments were performed to determine the effect of caterpillar feeding damage on wasp foraging behavior and to determine the relative importance of visual and olfactory plant cues for foraging wasps. In an experiment using caterpillar-damaged leaves, wasps took significantly more larvae from the previously damaged plants compared to the controls in the experiments with tobacco plants, but wasps did not distinguish between damaged and control plants in the experiments with tomato plants. Another experiment indicated that wasps use a combination of visual and olfactory cues of plant damage in their search for prey rather than just visual or olfactory cues alone. Furthermore, these results suggest that leaf shape may affect wasp detection of caterpillar feeding damage and thus detection of prey.
ERK5/KLF4 signaling as a common mediator of the neuroprotective effects of both nerve growth factor and hydrogen peroxide preconditioning.

Oxidative stress has long been implicated in the pathogenesis of various neurodegenerative disorders such as Alzheimer’s disease and stroke. While high levels of oxidative stress are generally associated with cell death, a slight rise of reactive oxygen species (ROS) levels can be protective by “preconditioning” cells to develop a resistance against subsequent challenges. However, the mechanisms underlying such preconditioning (PC)-induced protection are still poorly understood. Previous studies have supported a role of ERK5 (mitogen-activated protein [MAP] kinase 5) in neuroprotection and ischemic tolerance in the hippocampus. In agreement with these findings, our data suggest that ERK5 mediates both hydrogen peroxide (H2O2)-induced PC as well as nerve growth factor (NGF)-induced neuroprotection. Activation of ERK5 partially rescued pheochromocytoma PC12 cells as well as primary hippocampal neurons from H2O2-caused death, while inhibition of ERK5 abolished NGF or PC-induced protection. These results implicate ERK5 signaling as a common downstream pathway for NGF and PC. Furthermore, both NGF and PC increased the expression of the transcription factor, KLF4, which can initiate an anti-apoptotic response in various cell types. Induction of KLF4 by NGF or PC was blocked by siERK5, suggesting that ERK5 is required in this process. siKLF4 can also attenuate NGF- or PC-induced neuroprotection. Overexpression of active MEK5 or KLF4 in H2O2-stressed cells increased Bcl-2/Bax ratio and the expression of NAIP (neuronal apoptosis inhibitory protein). Taken together, our data suggest that ERK5/KLF4 cascade is a common signaling pathway shared by at least two important mechanisms by which neurons can be protected from cell death.
GABAA receptor subunit expression and assembly in cultured rat cerebellar granule neurons.

Abstract The assembly of multisubunit GABAA receptors in specific neuronal populations is a complex process which is poorly understood. To begin to examine receptor assembly, α1, β2/3, and γ2 subunit polypeptide expression and association, as well as receptor binding, were examined in cultured rat cerebellar granule neurons. Western blots revealed two α1-immunoreactive proteins. A 39 kDa species was maximal at 2 days in culture and subsequently declined. In contrast, a 51 kDa polypeptide, the anticipated size of the mature α1 subunit, was first detected at 4 days and increased throughout the culture period. Additional studies demonstrated that the β2/3 and γ2 subunits were detectable at 2 days and attained maximal levels by 6 days. The level of [3H]Ro15-1788 binding, a measure of assembled receptors, rose in parallel with the increases in the 51 kDa α1, β2/3, and γ2 subunits. Moreover, the 51 kDa α1, β2/3, and γ2 subunits were associated in receptor complexes. However, immunohistochemical studies demonstrated the presence of substantial intracellular subunit staining. This finding suggests that only some of the subunits expressed in granule neurons contribute to functional GABAA receptors on the cell surface.
Statistical Theory of Correlations in Random Packings of Hard Particles

A random packing of hard particles represents a fundamental model for granular matter. Despite its importance, analytical modeling of random packings remains difficult due to the existence of strong correlations which preclude the development of a simple theory. Here, we take inspiration from liquid theories for the $n$-particle angular correlation function to develop a formalism of random packings of hard particles from the bottom up. A progressive expansion into a shell of particles converges in the large layer limit under a Kirkwood-like approximation of higher-order correlations. We apply the formalism to hard disks and predict the density of two-dimensional random close packing (RCP), ${\ensuremath{\phi}}_{\mathrm{rcp}}=0.85\ifmmode\pm\else\textpm\fi{}0.01$, and random loose packing (RLP), ${\ensuremath{\phi}}_{\mathrm{rlp}}=0.67\ifmmode\pm\else\textpm\fi{}0.01$. Our theory also predicts a phase diagram and angular correlation functions that are in good agreement with experimental and numerical data.
Preservation of Bartonella muris in the Frozen State

SummaryThe infectivity of Bartonella muris can be preserved for at least 11 weeks when infected defibrinated rat blood is rapidly frozen in a mixture of dry ice and alcohol and then preserved in dry ice.
Analytical and numerical solution of a generalized Stefan problem exhibiting two moving boundaries with application to ocean delta formation

Abstract A model associated with the formation of sedimentary ocean deltas is presented. This model is a generalized one-dimensional Stefan problem bounded by two moving boundaries, the shoreline and the alluvial-bedrock transition. The sediment transport is a non-linear diffusive process; the diffusivity modeled as a power law of the fluvial slope. Dimensional analysis shows that the first order behavior of the moving boundaries is determined by the dimensionless parameter 0 ⩽ R a b ⩽ 1 —the ratio of the fluvial slope to bedrock slope at the alluvial-bedrock transition. A similarity form of the governing equations is derived and a solution that tracks the boundaries obtained via the use of a numerical ODE solver; in the cases where the exponent θ in the diffusivity model is zero (linear diffusion) or infinite, closed from solutions are found. For the full range of the diffusivity exponents, 0 ⩽ θ → ∞ , the similarity solution shows that when R a b 0.4 there is no distinction in the predicted speeds of the moving boundaries. Further, within the range of physically meaningful values of the diffusivity exponent, i.e., 0 ⩽ θ ∼ 2 , reasonable agreement in predictions extents up to R a b ∼ 0.7 . In addition to the similarity solution a fixed grid enthalpy like solution is also proposed; predictions obtained with this solution closely match those obtained with the similarity solution.
Diagnosis of acute knee injuries with hemarthrosis

One hundred thirteen consecutive athletes, who had sustained significant acute trauma to the knee with immediate disability and the early onset of hemarthrosis but who did not have demonstrable clinical laxity, were examined under anesthesia and had arthroscopy within 3 weeks of injury (the majority within 10 days). Lesions of surgical significance were found in 102 of the 113 cases (90%). Anterior cruciate ligament tears were present in 81 (72%), of which two-thirds also had associ ated meniscus lesions. Major meniscus tears with no associated cruciate lesions were found in 17 cases (15%), osteochondral fractures in 7 cases (6%), posterior cruciate ligament tears in 3 cases (3%), and no internal derangement in 5 cases (4%). Acute knee injuries with hemarthrosis, rather than being a contraindication to arthroscopy, are in fact one of the best indications for use of this procedure.
Presynaptic k-Opioid and Muscarinic Receptors Inhibit the Calcium-Dependent Component of Evoked Glutamate Release from Striatal Synaptosomes

In addition to cytosolic efflux, reversal of excitatory amino acid (EAA) transporters evokes glutamate exocytosis from the striatum in vivo. Both kappa-opioid and muscarinic receptor agonists suppress this calcium-dependent response. These data led to the hypothesis that the calcium-independent efflux of striatal glutamate evoked by transporter reversal may activate a transsynaptic feedback loop that promotes glutamate exocytosis from thalamo- and/or corticostriatal terminals in vivo and that this activation is inhibited by presynaptic kappa and muscarinic receptors. Corollaries to this hypothesis are the predictions that agonists for these putative presynaptic receptors will selectively inhibit the calcium-dependent component of glutamate released from striatal synaptosomes, whereas the calcium-independent efflux evoked by an EAA transporter blocker, L-trans-pyrrolidine-2,4-dicarboxylic acid (L-trans-PDC), will be insensitive to such receptor ligands. Here we report that a muscarinic agonist, oxotremorine (0.01-10 microM), and a kappa-opioid agonist, U-69593 (0.1-100 microM), suppressed the calcium-dependent release of glutamate that was evoked by exposing striatal synaptosomes to the potassium channel blocker 4-aminopyridine. The presynaptic inhibition produced by these ligands was concentration dependent, blocked by appropriate receptor antagonists, and not mimicked by the delta-opioid agonist [D-Pen2,5]-enkephalin. The finding that glutamate efflux evoked by L-trans-PDC from isolated striatal nerve endings was entirely calcium independent supports the notion that intact basal ganglia circuitry mediates the calcium-dependent effects of this agent on glutamate efflux in vivo. Furthermore, because muscarinic or kappa-opioid receptor activation inhibits calcium-dependent striatal glutamate release in vitro as it does in vivo, it is likely that both muscarinic and kappa receptors are inhibitory presynaptic heteroceptors expressed by striatal glutamatergic terminals.
LiF and CaF2:Mn thermoluminescent dosimeters in tandem.

Abstract Thermoluminescent dosimeters employing two or more different phosphors can be used for measuring the dose from different components of a radiation field. In particular two phosphors of differing atomic numbers can be utilized to measure the effective energy of an X- or γ-ray field. If their glow-peak temperatures differ sufficiently, or if a time delay can be applied to the heating of one or the other phosphor, their thermoluminescence signals can be separately measured in a single heating operation. The resulting combined glow curve contains, in peak height or area of either glow-peak, the dose or exposure reading. The ratio of peak heights (or areas) yields the effective energy. Such a tandem dosimeter, employing extruded LiF (TLD-700) and hot-pressed CaF 2 :Mn, has been constructed and its performance explored.
Size Distribution of High Weight Species in Pectin Fractions from Idared Apples

The apparent MW of two apple pectin fractions were investigated using gel permeation chromatography. Both fractions behaved similarly on Sephadex G–200, Sepharose 6B, and Bio Gel 50m. Seventy percent of galacturonic acid residues eluted in a continuous distribution in the range 12.5 million to 1 million Daltons. Ten percent lay above this range, twenty percent below. These high weight species (possibly aggregates) do not appear to be artifacts of the extraction and handling procedures used, and may reflect an intrinsic property of some pectic substances.
Another Look at Travel Patterns and Urban Form: The US and Great Britain:

This paper explores the relationship between land-use patterns and individual mobility from a comparative international perspective. There is a vast literature on US automobile dependence. Major ex...
Electrical capacitance volume tomography with high contrast dielectrics using a cuboid sensor geometry

An electrical capacitance volume tomography system has been created for use with a new image reconstruction algorithm capable of imaging high contrast dielectric distributions. The electrode geometry consists of two 4 × 4 parallel planes of copper conductors connected through custom built switch electronics to a commercially available capacitance to digital converter. Typical electrical capacitance tomography (ECT) systems rely solely on mutual capacitance readings to reconstruct images of dielectric distributions. This paper presents a method of reconstructing images of high contrast dielectric materials using only the self-capacitance measurements. By constraining the unknown dielectric material to one of two values, the inverse problem is no longer ill-determined. Resolution becomes limited only by the accuracy and resolution of the measurement circuitry. Images were reconstructed using this method with both synthetic and real data acquired using an aluminium structure inserted at different positions within the sensing region. Comparisons with standard two-dimensional ECT systems highlight the capabilities and limitations of the electronics and reconstruction algorithm.
A simple economic model of cocaine production

This paper presents a simple equilibrium model of the cocaine industry in Peru, Bolivia, and Colombia (PBC). The purpose of the model is to represent the fundamental economic relations that determine the size of cocaine output, and to simulate the effects on the production sector of policy initiatives or other changes in the surrounding environment. Model results include: ''Crop substitution'' programs will have a neglible impact on the world cocaine market. Cocaine supply control strategies that seize and destroy 70% or less of production, without limiting the total level of production, will have little impact on the market. Changes in the size of the world cocaine market have a relatively modest long-run impact on the standard of living of average workers in Peru, Bolivia, and Colombia. The results of this study are insensitive to the data uncertainties concerning the cocaine market.
National trends in discharge disposition after hepatic resection for malignancy

Background There is a paucity of data on the trends in discharge disposition for patients undergoing hepatic resection for malignancy.
A neutron-multiplicity sorter for the experimental determination of

Abstract An electronic circuit is described which, when presented with the discriminator-output pulses from a large, high-efficiency neutron-detection system, digitally sorts the number of pulses occurring in an adjustable count gate period and presents these data in both individual-line from to be recorded on a set of scalers and in analog form, suitable for analysis on a multi-channel analyzer. This is accomplished through the use of modern integrated-circuit technology and, when using the analog output/multichannel-analyzer method of collection, greatly simplifies the taking and presentation of the data. The sorter electronics consists of one printed-circuit board mounted in a 3-inch wide NIM module and operates from the ±12 V dc supply available from a standard NIM electronic bin.
Use of Split-Thickness Dermal Graft in the Surgical Treatment of Corneal and Scleral Defects

We used split-thickness dermal grafts for the surgical treatment of corneal and scleral perforations in two patients and obtained excellent results. Patient 1 had severe lye burns and bilateral corneal perforations and Patient 2 had scleromalacia perforans. The dermal graft self-epithelializes and, thus, does not need to be covered by conjunctiva; is supple, without the bulkiness of other materials, particularly cartilage and periosteum; is hearty and flourishes on avascular surfaces such as cornea and sclera; has good tensile strength; and is autogenous.
TGF-beta1 production in radiation nephropathy: role of angiotensin II

Purpose: Angiotensin II receptor antagonists are effective in the prophylaxis of radiation nephropathy. Studies were designed to determine whether TGF- beta 1, a fibrogenic cytokine, plays a role in mediating the protective effect of AII antagonism. These studies explored the time-course of glomerular TGF- beta 1 production in the irradiated kidney, and whether AII mediates TGF beta 1 production in glomeruli isolated from irradiated rats. Materials and methods: Rats received 20Gy of bilateral renal irradiation in five fractions and were randomized to receive an AII type 1 receptor antagonist (L-158,809) at 20mg/l in their drinking water, or no treatment. Drug therapy began 9 days prior to irradiation and continued for the duration of the study. Results: Analysis of renal function showed a significant increase in urinary proteinuria and blood urea nitrogen by 37 days and 63 days after irradiation, respectively. Estimation of glomerular TGF- beta 1 levels by quantitative sandwich enzyme immunoassay techniqu...
Tuning the emission of CdSe quantum dots by controlled trap enhancement.

Ligand exchange with 3-mercaptopropionic acid (MPA) has been successfully used to tune the emission intensity of trioctylphosphineoxide/dodecylamine-capped CdSe quantum dots. Addition of 3-mercaptopropionic acid (MPA) to CdSe quantum dot suspension enhances the deep trap emission with concurrent quenching of the band edge emission. The smaller sized quantum dots, because of larger surface/volume ratio, create a brighter trap emission and are more easily tuned. An important observation is that the deep trap emission which is minimal after synthesis is brightened to have a quantum yield of 1−5% and can be tuned based on the concentration of MPA in solution with the quantum dots. Photoluminescence decay and transient absorption measurements reveal the role of surface bound MPA in altering the photophysical properties of CdSe quantum dots.
SEASONAL FLUCTUATIONS IN TISSUE NITROGEN, PHOSPHORUS, AND N:P FOR FIVE MACROALGAL SPECIES COMMON TO THE PACIFIC NORTHWEST COAST1

Variations in tissue nitrogen (N) and phosphorus (P) were examined over a complete seasonal cycle for five macroalgae common in Oregon coastal water. Tissue N ranged from 2.0 to 5.5% dry weight (dry wt) in leafy macroalgae (Enteromorpha intestinalis (Linnaeus) Link. Ulva fenestrata Postels et Ruprecht, and Porphyra sp.) and from 0.9 to 2.6% drt wt in branched macroalgae (Codium fragile (Suringar) Hariot and Pelvetiopsis limitata Setchell). Tissue P ranged from 0.32 to 0.86% dry wt in leafy macroalgae and from 0.27 to 0.50% dry wt in branched macroalgae, Ulva fenestrata, C. fragile, and P. limitata appeared to be N limited during part of the year based on tissue N levels. Variations in N:P showed a more distinct seasonal pattern than either tissue N and tissue P. All macroalgae examined appeared to be N limited at least part of the year based on N:P composition, and P limitation occurred for all macroalgae examined except C. fragile. Our results suggest that tissue N:P ratio for macroalgae may be a good index for evaluating in situ nutrient status.
Epidermal growth factor enhances intestinal adaptation after massive small bowel resection

Abstract Epidermal growth factor (EGF) has documented trophic effects on several tissues, including small bowel (SB) mucosa. The purpose of this study was to determine the effect of EGF on intestinal adaptation after massive resection. Young Sprague-Dawley rats (weight, 154 ± 8.6 g) underwent a 75% proximal SB resection, with primary reanastomosis, and were continuously infused with equivalent volumes of either saline or human recombinant EGF (6.25 μg/kg/h) via a subcutaneous osmotic pump. In other animals, the SB was transected and reanastomosed without resection and either saline or EGF was infused. The animals were allowed standard rat chow and water ad libitum and were killed after 28 days. SB was harvested and subjected to histological examination. Intestinal mucosa was analyzed for total DNA and protein contents. After massive SB resection, subcutaneous administration of EGF resulted in significantly increased animal weight (294.5 ± 16 v 242.8 ± 14 g; P v 37.2 ± 6.0 cm; P v 7.4 ± 1.6 g; P v 0.68 ± 0.2 mm; P
Involvement of the p38 MAP kinase in Cr(VI)-induced growth arrest and apoptosis

Hexavalent chromium [Cr(VI)] is a carcinogenic genotoxin commonly found in industry and the environment. DNA damage resulting from Cr(VI) exposure triggers numerous stress responses, including activation of cell cycle checkpoints and initiation of apoptosis. Mechanisms controlling these responses, while extensively studied, have yet to be fully elucidated. Here, we demonstrate that the p38 mitogen-activated protein kinase (MAPK) is activated by Cr(VI) exposure and that inhibition of p38 function using the selective inhibitor SB203580 results in abrogation of S-phase and G2 cell cycle checkpoints in response to Cr(VI). Also, we observe that inhibition of p38 results in decreased cell survival and increased percentage of apoptotic cells following Cr(VI) treatment. Taken together, these results indicate that p38 function is critical for optimal stress response induced by Cr(VI) exposure.
Precise Developmental Gene Expression Arises from Globally Stochastic Transcriptional Activity

Summary Early embryonic patterning events are strikingly precise, a fact that appears incompatible with the stochastic gene expression observed across phyla. Using single-molecule mRNA quantification in Drosophila embryos, we determine the magnitude of fluctuations in the expression of four critical patterning genes. The accumulation of mRNAs is identical across genes and fluctuates by only ∼8% between neighboring nuclei, generating precise protein distributions. In contrast, transcribing loci exhibit an intrinsic noise of ∼45% independent of specific promoter-enhancer architecture or fluctuating inputs. Precise transcript distribution in the syncytium is recovered via straightforward spatiotemporal averaging, i.e., accumulation and diffusion of transcripts during nuclear cycles, without regulatory feedback. Common expression characteristics shared between genes suggest that fluctuations in mRNA production are context independent and are a fundamental property of transcription. The findings shed light on how the apparent paradox between stochastic transcription and developmental precision is resolved.
Modified block uniform resampling (BURS) algorithm using truncated singular value decomposition: Fast accurate gridding with noise and artifact reduction

The block uniform resampling (BURS) algorithm is a newly proposed regridding technique for nonuniformly-sampled k-space MRI. Even though it is a relatively computationally intensive algorithm, since it uses singular value decomposition (SVD), its procedure is simple because it requires neither a pre- nor a postcompensation step. Furthermore, the reconstructed image is generally of high quality since it provides accurate gridded values when the local k-space data SNR is high. However, the BURS algorithm is sensitive to noise. Specifically, inaccurate interpolated data values are often generated in the BURS algorithm if the original k-space data are corrupted by noise, which is virtually guaranteed to occur to some extent in MRI. As a result, the reconstructed image quality is degraded despite excellent performance under ideal conditions. In this article, a method is presented which avoids inaccurate interpolated k-space data values from noisy sampled data with the BURS algorithm. The newly proposed technique simply truncates a series of singular values after the SVD is performed. This reduces the computational demand when compared with the BURS algorithm, avoids amplification of noise resulting from small singular values, and leads to image SNR improvements over the original BURS algorithm. Magn Reson Med 46:1189–1201, 2001. © 2001 Wiley-Liss, Inc.
The influence of gender on children's ratings of fear in self and same-aged peers.

Abstract In the present study, gender differences in children's fear were examined. Nine-year-old children were asked to rate their own fears, the fears of their peers of the opposite gender, and the fears of their peers of the same gender, using the Fear Survey Schedule for Children—Revised (Ollendick, 1983). Consistent with previous investigations, the results revealed that boys rated themselves as less fearful than girls. In addition, both male and female judges rated “other boys” as less afraid than “other girls.” These findings emerged whether fear was examined in terms of intensity or prevalence. Implications and suggestions for future research are discussed.
Direct quantitative analysis of lysophosphatidic acid molecular species by stable isotope dilution electrospray ionization liquid chromatography-mass spectrometry.

In order to better understand the role of lysophosphatidic acid (LPA) in physiology and pathophysiology, it is necessary to accurately determine the molecular species and amounts of LPA in biological samples. We have developed a stable-isotope dilution, liquid chromatography-mass spectrometry assay for the direct quantitative analysis of 1-acyl-LPA. This method utilizes a deuterium-labeled internal standard, LPA (18:0-d(35)), and a single liquid-liquid extraction with acidic butanol that allows >95% recovery of LPA, followed by online normal-phase liquid chromatography-mass spectrometry. This protocol allows for the accurate, sensitive, and reproducible analysis of the individual 1-acyl-LPA species present in biological samples. The utility of the assay is demonstrated through the analysis of LPA species in plasma and serum from human volunteers. Total LPA in EDTA plasma was 0.61 +/- 0.14 microM in males and 0.74 +/- 0.17 microM in females, which increased to 0.91 +/- 0.23 and 0.99 +/- 0.38 microM after incubation for 24 h at 25 degrees C. Total LPA in serum was 0.85 +/- 0.22 microM in males and 1.57 +/- 0.56 microM in females, which increased to 4.78 +/- 0.89 and 5.57 +/- 0.73 microM after incubation for 24 h at 25 degrees C.