cssi/SciSciGPT-SciSciNet huggingface dataset:
Superconducting characteristics of zirconium—vanadium alloys

The critical temperatures, Tc, and critical current density, Jc were measured for ZrV alloys containing 6 and 9 at% V at various stages of aging at 500 °C. The microstructure of the samples was determined by metallographic and X-ray diffraction techniques in conjunction with previously reported studies. The alloys were found to contain mixtures of martensite α′, complex (h.c.p.) ω and retained (b.c.c.) β phases. Aging resulted in the transformation of these phases to the equilibrium phases, (h.c.p.) Zr-rich α, and the superconducting (at 4.2 °K) intermetallic compound V2Zr. The Tc and Jc results are interpreted in terms of the flux pinning capabilities of the resulting microstructures. Die kritischen Temperaturen Tc und die kritische Stromdichte Jc wurden an ZrV Legierungen mit 6 und 9 At% V in verschiedenen Alterungszustanden bei 500 °C gemessen. Die Mikrostrukturen der Proben wurden mit metallographischen Methoden und Rontgenstreuung in Verbindung mit fruher berichteten Untersuchungen bestimmt. Es wurde gefunden, das die Legierungen Mischungen von Martensit α′-, komplexen (h.d.p.) ω- und ubriggebliebenen (k.r.z.) s-Phasen enthielten. Alterung bestand in der Transformation dieser Phasen zu den Gleichgewichtsphasen: der (h.d.p.) Zr-reichen α-Phase und der (bei 4.2 °K) supraleitenden intermetallischen Verbindung V2Zr. Die Tc- und Jc− Ergebnisse werden mit der Moglichkeit der Flusfestsetzung der resultierenden Mikrostrukturen interpretiert.
Microanatomy of dendritic spines: emerging principles of synaptic pathology in psychiatric and neurological disease.

Abstract Psychiatric and neurologic disorders ranging from mental retardation to addiction are accompanied by structural and functional alterations of synaptic connections in the brain. Such alterations include abnormal density and morphology of dendritic spines, synapse loss, and aberrant synaptic signaling and plasticity. Recent work is revealing an unexpectedly complex biochemical and subcellular organization of dendritic spines. In this review, we highlight the molecular interplay between functional domains of the spine, including the postsynaptic density, the actin cytoskeleton, and membrane trafficking domains. This research points to an emerging level of analysis—a microanatomical understanding of synaptic physiology—that will be critical for discerning how synapses operate in normal physiologic states and for identifying and reversing microscopic changes in psychiatric and neurologic disease.
Preservice teachers' theory development in physical and simulated environments

We report a study of three prospective secondary science teachers' development of theories- in-action as they worked together in a group to explore collisions using both physical manipulatives and a computer simulation (Interactive Physics). Analysis of their investigations using an existing theoretical framework indicates that, as the group moved from physical experiments to the computer simulation, their attention shifted from planning their experiments to processing system feedback, which impeded the iterative refinement of their theories-in-action. The nature of the theories they developed also changed. Learners' attitudes toward science and prior experiences affected the exploration process in both environ- ments. In particular, prior instruction in physics and an authoritarian view of science seemed to impede engagement in the development and testing of theories-in-action. Certain features of the computer system itself also impeded exploration. 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 907-937, 2006 One of the goals of science education at the secondary level is that our students will ''actually use the cognitive and manipulative skills associated with the formulation of scientific explanations'' (National Research Council, 1996, p. 173). That is, we want our students to observe phenomena, formulate ideas that might explain what they see, and implement strategies to test whether these ideas are correct and over what range of parameters they hold true. In an ideal situation, students will formulate ideas that align with the explanations that have been developed by the larger community of scientists, but significant forces work against this possibility. First, it is unlikely that students working without guidance or prior knowledge will formulate ''ontological entities (and) organizing concepts'' (Driver, Asoko, Leach, Mortimer, & Scott, 1994, p. 6) that are as sophisticated and productive as those generally accepted by the discipline, the latter having been developed through years of evaluation by a dedicated community of scholars toward a general consensus. A case in point is the kinetic energy construct—that the energy
Contribution of mesenchymal cell death and mitotic alteration to asymmetric limb malformations induced by MNNG.

N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) induces fetal asymmetric limb malformations with exposure of pregnant mice to 50 mg/kg on day 11 of gestation. Hindlimbs were more frequently malformed than forelimbs, and a fourfold greater incidence of postaxial ectrodactyly was found in left forelimbs than in right forelimbs, and a two fold excess in left hindlimbs compared to right hindlimbs. The level of cell death and mitotic index were measured in forelimbs and hindlimbs from treated and control embryos at 1, 4, 18, 24, 48, and 72 hr after exposure to ascertain if these parameters could be correlated with the differential teratogenic susceptibility of the limbs. An increase in necrotic index was first detected in treated limbs at 4 hr, increased at 18 hr, peaked at 24 hr, and began declining at 48 hr to reach the control baseline at 72 hr. At 24 hr, the correlation between the level of cell death and susceptibility of malformation was the strongest, with the left hindlimb having a necrotic index of 58%, the right hindlimb 47%, the left forelimb 30% and the right forelimb 12%. In both forelimbs and hindlimbs, MNNG treatment initially depressed mitotic activity followed by an elevation at 48 hr relative to controls. The magnitude of the depression, extent of the elevation, and overall pattern of mitotic activity could not be uniformly related to limb defects. These results indicate that the amount of cell death in limb buds at 24 hr after MNNG exposure may predict target organ susceptibility. Depressions in mitotic activity and alterations in the pattern of mitosis were also observed which were not as clearly correlated with the incidence of malformations as was the amount of cell death.
Correction of species transformations in the analysis of Cr(VI) in solid environmental samples using speciated isotope dilution mass spectrometry

Speciation of Cr(VI) in solid environmental samples is challenging because of the transformations between Cr(VI) and Cr(III). EPA method 3060A completely extracts Cr(VI) in a hot alkaline solution and preserves the solublized Cr(VI). This procedure, however, can oxidize Cr(III) in some chemical forms. On the other hand, the reverse transformation may occur during neutralization and acidification following the extraction step. We developed a method that is capable of monitoring and correcting for such bidirectional species transformations to determine Cr(VI) in solid samples. In this method, we spike a sample with a 53Cr(VI) spike (enriched in 53Cr) and a isoCr(III) spike (enriched in 50Cr). The large quantity of isoCr(III) in an easily oxidizable form competes with sample Cr(III) in the oxidization, reducing the method-induced oxidation of sample Cr(III). This method also corrects for the reduction of Cr(VI). The theory is presented and is evaluated experimentally. The analysis of chromite ore processing ...
The IκB proteins: members of a multifunctional family

The I kappa B proteins bind to Rel/NF-kappa B transcription factors and modulate their activities. Although originally described only as cytoplasmic inhibitors of Rel/NF-kappa B transcription complexes, it is now clear that I kappa B proteins also have other functions.
A COMPARISON OF THE LONG-TERM SURVIVAL OF 306,868 PATIENTS WITH MULTIVESSEL CORONARY ARTERY DISEASE UNDERGOING CABG AND PCI: A META-ANALYSIS OF RETROSPECTIVE STUDIES

Several randomized control trials have reported conflicting results concerning mortality between CABG and PCI. The purpose of this study was to conduct a meta-analysis of recent retrospective studies examining the long-term mortality of patients with multi-vessel coronary artery disease undergoing
A max–min ant colony system for assembly sequence planning

An improved ant colony optimization (ACO)-based assembly sequence planning (ASP) method for complex products that combines the advantages of ant colony system (ACS) and max–min ant system (MMAS) and integrates some optimization measures is proposed. The optimization criteria, assembly information models, and components number in case study that reported in the literatures of ACO-based ASP during the past 10 years are reviewed and compared. To reduce tedious manual input of parameters and identify the best sequence easily, the optimization criteria such as directionality, parallelism, continuity, stability, and auxiliary stroke are automatically quantified and integrated into the multi-objective heuristic and fitness functions. On the precondition of geometric feasibility based on interference matrix, several strategies of ACS and MMAS are combined in a max–min ant colony system (MMACS) to improve the convergence speed and sequence quality. Several optimization measures are integrated into the system, among which the performance appraisal method transfers the computing resource from the worst ant to the better one, and the group method makes up the deficiency of solely depending on heuristic searching for all parallel parts in each group. An assembly planning system “AutoAssem” is developed based on Siemens NX, and the effectiveness of each optimization measure is testified through case study. Compared with the methods of priority rules screening, genetic algorithm, and particle swarm optimization, MMACS is verified to have superiority in efficiency and sequence performance.
A metabolic model for the determination of shell composition in the bivalve mollusc, Mytilus edulis

Rosenberg. G. D. & Hughes, W. W. 1991 01 15: A metabolic model for the determination of shell composition in the bivalve mollusc, Mytilus edulis. Lethaia, Vol. 24. pp. 83–96. Oslo. ISSN 0024–1164. This research describes compositional variations within the shell of the extant mussel Mytilur edulis and proposes that they are produced by metabolic gradients within the shell-secreting mantle. Because we have previously proposed that the same metabolic gradients are responsible for variations in shell form (curvature), we establish here a model for molluscan shell growth integrating. for the first time. shell form and composition with mantle metabolism. The electron microprobe was used to measure the distribution of Mg. S, and Ca in the outer calcitic shell layer of sectioned. polished, and either A1- or C-coated shell. Mg/Ca and S/Ca ratios in the outer shell are respectively 1.25 and 1.40 times higher along slow-growing, commissure-umbo axes of high shell curvature and high metabolic activity than along rapidly growing axes of low curvature and low metabolic activity. The ratios within the inner surface of the calcitic shell layer decline most rapidly along commissure-umbo axes where mantle metabolic activity also declines rapidly. We reject the null hypothesis, generally at high levels of significance (1-tests. F-tests. regression analyses, and discriminant analysis. with p 4 0.01) that there is no difference in either Mg or S concentration in sections of the calcitic shell layer that differ in shell curvature and mantle metabolic activity. We conclude that calcium (mineral)-rich portions of shells are energctically less costly to produce than matrix or minor element-rich portions. in agreement with the proposal that natural selection favors mineral-rich shells because they are more efficient to produce than matrix-rich shells. Among-specimen differences are also highly significant (mixed model ANOVA). This confirms our assertion that paleontologists need to describe variations in skeletal composition among populations and throughout ontogeny as systematically as classical taxonomists describe morphology. if ever the environmental and the genetic influences on skeletal composition are to be distinguished. Bivalves. biomineralization, shell composition. magnesium, sulfur, calcium, metabolism, growth. Mytillus edulis
Optimal process parameters under LINEX loss function with general input quality characteristic

In this paper we generalize the quality and cost trade-off problem of Chang and Hung (Qual Quant 41: 291–301, 2007) under the LINEX loss function. We consider the general input characteristic given by the random variable X with moment generating function mX(t) and output characteristic given by the deterministic transformation Y = g(X). The two cases we consider are when g(X) is an affine function of X and X follows (1) the gamma distribution, and (2) the double exponential distribution.
Effect of preacquisition UCS exposure on classical conditioning of the rabbit's nictitating membrane response☆

Abstract Conditioning of the rabbit nictitating membrane response was found to be inversely related to the number (0, 50, 200, 350) and intensity, (0, 1, 3, 5 mA) of preacquisition UCS exposures and directly related to the interval between preexposure and acquisition (0 or 24 hr). The results were discussed in terms of sensory adaptation, habituation, blocking, and emotional reactivity.
The Determination of Apparent Isoelectric Points of Cell Structures by Staining at Controlled Reactions

The staining reactions at controlled pH-values of various dyes with the nucleus and cytoplasm of Trichonympha collaris under different conditions were investigated. When staining intensity was plotted against pH, it was found that with each dye a different curve was obtained. “Isoelectric points” obtained by superposition of acid and basic dye curves varied for the same material with the dyes employed. It was found that, with the same dye, the curves of staining intensity plotted against pH varied with the buffer system utilized. Moreover, the intensity of staining at any pH was found to vary directly with the concentration of dye and inversely with the concentration of buffer. Various factors modifying staining intensity were studied. In the staining of a protein in buffered solution, it was shown that staining intensity (the index of the concentration of the dye-protein compound) at a given pH-value is dependent upon the interaction of the dye-protein, buffer-protein and dye-buffer systems, and that as ...
The national impact of the 1995 changes to the UNOS renal allocation system

In 1995, changes in the United Network for Organ Sharing (UNOS) renal allocation policies expanded the mandatory share (MS) category to include zero antigen mismatches (0 mm), increased points for waiting time and for pediatric status, and eliminated points for certain HLA match grades. Data from the national scientific registry on 11344 and 11652 renal allograft recipients were analyzed for periods prior to and following the policy changes to assess the impact on organ allocation. The overall frequency of transplants going to non-Caucasians increased between the study periods, but the increase was significant only in the MS category. The proportion of MS transplants nearly doubled for African-Americans, increasing from 5.5% to 10.5%, while Hispanic/Latino recipients experienced a smaller increase, from 7.2% to 8.9%. The increased numbers of MS transplants clearly resulted from the inclusion of the 0 mm in the MS category. Among the NMS transplants, the average number of mismatched HLA antigens increased slightly. No effect of the additional points for waiting time was observed among recipients of non-mandatory share (NMS) transplants. The increase in mean waiting time until transplant for NMS recipients was attributable to the growth in the size of the waiting list. In contrast, there was a significant increase in mean waiting time for MS recipients. There were no significant changes in the proportions of sensitized or pediatric recipients between the study periods. In conclusion, only the changes in the MS policies appeared to have any significant effect on renal allocation. Further efforts will be required to address increasing allocation to patients disadvantaged by sensitization and/or prolonged waiting times.
Analytical model for I-V characteristics of JFETs with heavily doped channels

Abstract A theoretical analysis of the I - V characteristics of junction field-effect transistors (JFETs) of types useful for electronic and optoelectronic integrated circuits, has been carried out in some detail. Attempts have been made to study the effects of various device parameters, including carrier degeneracy due to heavy doping of the channel, velocity overshoot of electrons in the channel and shortening of gate length, on the I - V characteristics of these JFETs. A new theoretical model for drift velocity v in semiconductors has been proposed for this purpose. A comparison of results from this model with those from the existing model of Trofimenkoff and with available experimental data for v attests at least to the high-field accuracy of the proposed model. Unlike almost all other models, the simple functional form of the proposed model provides it with additional advantages for application to the analytical I - V study of FETs with both uniformly and nonuniformly doped channels. Use of this model in the framework of the Lehovec-Zuleeg procedure for short-channel FETs appears to provide reasonably good results. Wherever experimental data are available, they agree at least qualitatively with results from the present model. The latter demonstrates that a very heavy doping in the p -type gate does not yield higher transconductance. A submicron gate and a heavy doping (higher than the nulled degeneracy level) in the channel are, on the other hand, necessary for higher drain saturation current and transconductance. A semiconductor alloy with the highest possible electron saturation velocity is the most suitable for high-speed JFETs.
The influence of national guidelines on antihypertensive prescribing patterns.

Efforts to influence medical practice include the formation of expert medical panels who make recommendations for the evaluation and treatment of clinical problems. Despite the considerable expense and effort that go into these activities, it is unclear whether they are successful. Recent studies have evaluated whether recommendations from the Fifth Joint National Committee on the Detection, Evaluation, and Treatment of High Blood Pressure (JNC V) published in 1993 influenced antihypertensive prescribing patterns. These included a national study of medications dispensed by retail pharmacies and an evaluation of antihypertensive prescribing patterns in US Veterans Affairs (VA) medical facilities. Despite recommendations from JNC V that hydrochlorothiazide and b-blockers be used as first choice for most hypertensive patients, calcium antagonists and angiotensin converting enzyme (ACE) inhibitors were the most common drugs prescribed for hypertension in both 1992 (before JNC V) and 1995 (after JNC V). In retail pharmacies, changes in antihypertensive drug dispensing patterns from 1992 to 1995 reflected increased use of calcium antagonists and ACE inhibitors and decreased use of diuretics and b-blockers, suggesting that JNC V recommendations had little effect on prescribing patterns. Similar patterns of antihypertensive drug use were found in VA facilities. The reasons for the lack of influence of JNC V recommendations on antihypertensive prescribing patterns must be explored and alternative ways of educating health care providers implemented.
The opto-electronic physics which just broke the efficiency record in solar cells (presentation video)

Solar cell science and technology is changing. New efficiency records have been set. Alta Devices has reached 28.8% efficiency in a thin film single-junction cell at 1-sun, and 30.8% efficiency in a thin-film dual junction cell at 1-sun. Counter-intuitively, efficient external fluorescence is a necessity for approaching the ultimate limits. A great Solar Cell also needs to be a great Light Emitting Diode. Why would a solar cell, intended to absorb light, benefit from emitting light? Although it is tempting to equate light emission with loss, paradoxically, light emission actually improves the open-circuit voltage, and the efficiency. The single-crystal thin film technology that achieved these high efficiencies, is created by epitaxial liftoff, and can be produced at cost well below the other less efficient thin film solar technologies. The path is now open to a 30% efficient photovoltaic technology that can be produced at low cost.
The role of silicate in the adsorption/desorption of arsenite on goethite

Abstract The importance of anion displacement as a mechanism for arsenic release was examined through the competitive adsorption and desorption of arsenite on goethite in the presence of silicate. Arsenite remained the only arsenic species throughout the adsorption studies. Oxyanion surface concentration versus time plots developed from adsorption experiments were analyzed with a kinetic rate equation to determine the apparent rate coefficients for arsenite and silicate alone and arsenite in the presence of pre-equilibrated silicate. Silicate adsorption on goethite was significantly slower than arsenite. FTIR analysis indicated that silicate polymerization on goethite may be related to the slow adsorption kinetics. Under all conditions pre-equilibrated silicate reduced the rate and total quantity of arsenite adsorbed. The percent increase in the final aqueous arsenite concentration ranged from 0.25 to 30% depending on the concentration of the adsorbed silicate and aqueous arsenite. Increases in the aqueous arsenite were greatest after 30 min before reaching a steady state after 150 min. Desorption experiments where silicate was introduced to previously adsorbed arsenite indicated that silicate was able to irreversibly displace between 0.3 and 1.5% of the adsorbed arsenite resulting in an increase in solution concentrations ranging from 9 to 266 μg L − 1 of arsenite. Experimental results demonstrate the importance of anion displacement as a mechanism for arsenic release. This is readily seen through the ability of silicate, a naturally occurring and ubiquitous oxyanion, to: 1) reduce arsenite adsorption rates, 2) block potential adsorption sites thereby reducing the total quantity of arsenite adsorbed, and 3) displace adsorbed arsenite. These three processes may ultimately result in an increase in the mobility and potential bioavailability of arsenite.
Methodologic issues in clinical evaluation of stenosis severity in adults undergoing aortic or mitral balloon valvuloplasty

Abstract Although both catheterization and Doppler measures of valvular stenosis severity have been validated, each has specific advantages and limitations, particularly in the setting of balloon valvuloplasty. Invasive valve area and mean pressure gradient recorded immediately before and after aortic (n = 589) or mitral (n = 608) catheter balloon valvuloplasty were compared with Doppler valve area and mean pressure gradient recorded For aortic stenosis, Doppler valve area ranged from 0.1 to 1.4 cm 2 before and 0.2 to 2.3 cm 2 after catheter balloon valvuloplasty. Doppler and invasive aortic valve areas differed by ≤0.5 cm 2 in 99% and by 2 in 92% of patients. Linear correlation was higher before versus after catheter balloon valvuloplasty, for both valve area (r = 0.49 vs r = 0.35, p = 0.01) and mean pressure gradient (r = 0.64 vs r = 0.50, p = 0.01). Group mean invasive valve area was slightly smaller before (0.50 vs 0.59 cm 2 , p 2 , p = 0.16) catheter balloon valvuloplasty. Variables affecting the valve area differences were cardiac output, aortic regurgitation, heart rate and blood pressure. Mean pressure gradient differences were related to echo quality, blood pressure and mitral regurgitation. For mitral stenosis, 2-dimensional echocardiographic valve area ranged from 0.4 to 2.8 cm 2 before and 0.7 to 3.8 cm 2 after catheter balloon valvuloplasty. Two-dimensional echocardiography and invasive mitral valve areas differed by ≤0.5 cm 2 in 96% and by 2 in 81% of cases. Linear correlation was not different before versus after catheter balloon valvuloplasty for two-dimensional echocardiographic valve area (r = 0.40 vs 0.36), pressure halftime valve area (r = 0.31 vs 0.32) or mean pressure gradient (r = 0.55 vs r = 0.46). Group mean 2-dimensional echocardiography and pressure halftime valve areas were larger than invasive valve areas before (1.09 vs 1.02 cm 2 , p = 0.001) and smaller after (1.71 vs 2.02 cm 2 , p Nonsimultaneous studies, differing volume flow measurements, and the underlying accuracy of each technique largely account for discrepancies between these methods. The clinical use of each will depend on its ability to predict long-term patient outcome.
Uncertainty middle-management: Personal certainty is not the core existential motive

Research in the field of social psychology has long demonstrated that people adopt attitudes and engage in a variety of behaviors that promote feelings of certainty (see Arkin, Oleson, & Carroll, in press). Van den Bos (this issue) proposes that seeking personal certainty is the core existential motive, or at least that the uncertainty management model would be the most profitable basis for social psychological research on existential concerns. Specifically, he asserts that “there are good reasons to postulate that the core existential motive underlying many models and many research findings is people’s striving to feel certain about themselves and their trying to deal with personal uncertainties” (p. 211). Although there are many elements of the uncertainty management model that we find intriguing and agreeable, and we applaud Van den Bos’ efforts to integrate related research and spark cross-theoretical discourse, we disagree that seeking personal certainty is the core existential motive. We also believe that the uncertainty management model cannot satisfactorily account for a major portion of extant research on existential strivings. On the following pages, we challenge the uncertainty management model by asserting that (a) certainty-strivings, as defined by Van den Bos (this issue), are often in the service of other motives; (b) existential strivings do not always bolster personal certainty; and (c) contrary to the claims of Van den Bos (this issue), the uncertainty management model cannot account for the bulk of research derived from terror management theory (TMT; Solomon, Greenberg, & Pyszczynski, 1991). We conclude by suggesting that one, but not the only, core existential motive is the desire to transcend death.
Equivalent ionospheric current systems representing IMF sector effects on the polar geomagnetic field

Abstract Equivalent ionospheric current systems representing IMF sector effects on the geomagnetic field in high latitudes are examined for each of the twelve calendar months by spherical harmonic analyses of geomagnetic hourly data at 13 northern polar stations for seven years. The main feature of obtained equivalent current systems includes circular currents at about 80° invariant latitude mostly in the daytime in summer and reversed circular currents at about 70° invariant latitude mainly at night in winter. Field-aligned current distributions responsible for equivalent currents, as well as vector distributions of electric fields and ionospheric currents, are approximated numerically from current functions of equivalent current systems by taking assumed distributions of the ionospheric conductivity. Two sets of upward and downward field-aligned current pairs in the auroral region, and also a field-aligned current region near the pole show seasonal variations. Also, ionospheric electric-field propagation along geomagnetic field lines from the summer hemisphere to the winter hemisphere with auroral Hall-conductivity effects may provide an explanation for the winter reversal of sector effects.
Holocene lake-level fluctuations and beach-ridge development along the northern shore of Lake Michigan, USA

Geomorphology of a beach-ridge complex and adjacent lake basins along the northern shore of Lake Michigan records fluctuations in the level of Lake Michigan for the last 8000 to 10 000 14C yr B.P. (radiocarbon years Before Present). A storm berm at 204.7–206 m (671.6–675.9 ft) exposed in a sandpit provides evidence of a pre-Chippewa Low lake level that is correlated with dropping water levels of Glacial Lake Algonquin (c. 10 300–10 100 14C yr B.P.). Radiocarbon dates from organic material exposed in a river cutbank and basal sediments from Elbow Lake, Mackinac Co., Michigan, indicate a maximum age of a highstand of Lake Michigan at 6900 14C yr B.P., which reached as high as 196.7 m (645 ft), during the early-Nipissing transgression of Lake Michigan. Basal radiocarbon dates from beach swales and a second lake site (Beaverhouse Lake, Mackinac Co.) provide geomorphic evidence for a subsequent highstand which reached 192.6 m (632 ft) at 5390±70 14C yr B.P.
Delayed sympathectomy after a prolonged hyperalgesia results in a subsequent enhanced acute hyperalgesic response

Abstract We report on the ability of a delayed sympathectomy after a prolonged hyperalgesia to result in a subsequent enhanced hyperalgesic response. Sympathectomy was performed one day after injection of prostaglandin E 2 plus rolipram, which induces a prolonged sympathetically-maintained hyperalgesia [Aley K. O. and Levine J. D. (1995) Eur. J. Pharmac. 273 , 107–112]. The duration of hyperalgesia produced by a subsequent injection of prostaglandin E 2 or prostaglandin E 2 plus rolipram was then assessed. Lumbar surgical sympathectomy, done on day 2 or 3, prevented prostaglandin E 2 plus rolipram-induced prolonged hyperalgesia from developing when they were injected five days after surgery, similar to the previous report of the effect of prior sympathectomy to block the rolipram enhancement [Aley K. O. and Levine J. D. (1995) Eur. J. Pharmac. 273 , 107–112]. Sympathectomy done five days after injection of prostaglandin E 2 plus rolipram, however, paradoxically prolonged (at least 10 days) hyperalgesia induced by a subsequent prostaglandin E 2 plus rolipram injection, a duration much greater than that seen after prostaglandin E 2 plus rolipram in naive animals. To determine the roles of prostaglandin E 2 and rolipram in the prolongation of hyperalgesic response after delayed sympathectomy, rats were treated with either prostaglandin E 2 or rolipram prior to sympathectomy. Prostaglandin E 2 or rolipram alone were also administered five days after the sympathectomy. It was found that sympathectomy done five days after first injecting either prostaglandin E 2 or rolipram alone did not produce enhanced hyperalgesic response. These data suggest that induction of a prolonged state of mechanical hyperalgesia causes time-dependent alterations in the sympathetic control of peripheral nociceptive mechanisms such that sympathectomy can lead to enhanced hyperalgesic response. These findings may be relevant to post-sympathectomy pain, a clinical entity for which there has been no available animal models.
Rat kidney mitochondrial carbonic anhydrase

Abstract Mitochondrial carbonic anhydrase has previously been quantitated in liver mitochondria; it was not detected in guinea pig kidney cortical mitochondria. Evidence of this enzyme in rat kidney cortical mitochondria is reported. Electron microscopy showed that intact mitochondria were free of other intracellular organelles. When intact kidney mitochondria were added to isotonic 3′-( N′ -morpholino) propanesulfonic acid buffer with 25 m m KHCO 3 (1% labeled with 18 O) the rate of disappearance of C 18 O 16 O was biphasic; this indicates that there is carbonic anhydrase within the inner mitochondrial membrane. Intact rat kidney mitochondria were assayed for carbonic anhydrase activity at 4 °C by the changing pH technique. The rate of CO 2 hydration in the presence and absence of intact mitochondria was identical; this rate increased when Triton X-100 was added which indicates that all carbonic anhydrase is inside the inner mitochondrial membrane. Carbonic anhydrase activity was quantitated as K enz (units, ml · s −1 mg −1 mitochondrial protein) at 37 °C, pH 7.4, in 25 m m NaHCO 3 (1% labeled with 18 O) by following the rate of disappearance of C 18 O 16 O from solutions before and after addition of disrupted mitochondria. Values of K enz for liver and kidney mitochondria from rats given free access to normal rat chow and water at neutral pH were 0.06 and 0.08 (respectively). Values of K enz for liver and kidney mitochondria from rats fed as above and with free access to water adjusted to pH 2.5 with HCl were 0.04 and 0.16, respectively. Values of K enz for rats starved for 48 h were 0.06 and 0.12 (respectively). The values of K enz remained 0.11-0.14 in liver mitochondria from guinea pigs fed normally, given dilute acid, or starved and the value was always at zero in guinea pig kidney mitochondria. Values of K enz were measured with disrupted mitochondria by the 18 O technique as a function of pH at 25 °C, 25 to 75 m m NaHCO 3 , ionic strength 0.3. From pH 7.0 to 8.0 K enz increased threefold for mitochondria from rat liver, fed rat kidney, and acid rat kidney, and increased eightfold for mitochondria from guinea pig liver. K enz was decreased similarly by increasing HCO − 3 in mitochondria from rat liver, fed kidney, and acid kidney; it is concluded that carbonic anhydrase in rat liver mitochondria is probably the same isozyme as in rat kidney mitochondria. The published observation that rat kidney cortices are up to 10 times as gluconeogenic from pyruvate as guinea pig kidney cortices can be explained by the presence of mitochondrial carbonic anhydrase in rat but not guinea pig mitochondria.
Protein phosphatase 2A inactivates Bcl2's antiapoptotic function by dephosphorylation and up-regulation of Bcl2-p53 binding.

Bcl2 is associated with chemoresistance and poor prognosis in patients with various hematologic malignancies. DNA damage-induced p53/Bcl2 interaction at the outer mitochondrial membrane results in a Bcl2 conformational change with loss of its antiapoptotic activity in interleukin-3–dependent myeloid H7 cells. Here we find that specific disruption of protein phosphatase 2A (PP2A) activity by either expression of small t antigen or depletion of PP2A/C by RNA interference enhances Bcl2 phosphorylation and suppresses cisplatin-stimulated p53/Bcl2 binding in association with prolonged cell survival. By contrast, treatment of cells with C2-ceramide (a potent PP2A activator) or expression of the PP2A catalytic subunit (PP2A/C) inhibits Bcl2 phosphorylation, leading to increased p53/Bcl2 binding and apoptotic cell death. Mechanistically, PP2A-mediated dephosphorylation of Bcl2 in vitro promotes its direct interaction with p53 as well as a conformational change in Bcl2. PP2A directly interacts with the BH4 domain of Bcl2 as a docking site to potentially “bridge” PP2A to Bcl2's flexible loop domain containing the target serine 70 phosphorylation site. Thus, PP2A may provide a dual inhibitory effect on Bcl2's survival function by both dephosphorylating Bcl2 and enhancing p53-Bcl2 binding. Activating PP2A to dephosphorylate Bcl2 and/or increase Bcl2/p53 binding may represent an efficient and novel approach for treatment of hematologic malignancies.
Exploring the crisis in information system education: Educators and executives concur on many issues

Educators and executives often have dissimilar conceptual frameworks regarding the background of information specialists. This results in varying perceptions about information system curricula. This paper addresses these differences and shows that, although educators and executives perceive the need for behavioral skills, academicians do not always stress the acquisition of such skills. Furthermore, the location of the information science courses affects course content. Within Information Science and Business Departments, there is a greater perceived emphasis on communication than within departments of mathematics or computer science.
Nitric acid-nitrate aerosol measurements by a diffusion denuder: A performance evaluation∗

A nitric acid diffusion denudcr made of nylon was operated in Riverside, CA, Houston, TX and Claremont, CA. The pre-exponential and diffusion coefficients for the first term of the Gormley-Kennedy equation were estimated by regressing the log (nitrate mass deposited) against the axial distance from the entrance of the denuder. The field study average values of the two coefficients were compared by the two-tail t-test to the average values for the HNO3-air system determined in the laboratory; the hypothesis that the means of the diffusion coefficients are equal may be rejected at the < 5% level of significance. The nitrate ion mass patterns in the denuder for the field cases do not adhere to the Gormley-Kennedy model applied to the simple HNO3-air system. The source of excess nitrate deposited in the nylon tube could not be identified by this analysis. Candidate sources are deposition of gaseous N-compounds (analyzed as nitrate) other than nitric acid and release of nitric acid vapor from particles during transit in the denuder tube.
PUBLIC INFRASTRUCTURE, PRIVATE BUILT INVESTMENT, AND LOCAL PLANNING CAPACITY: AN EXAMINATION OF LINKAGES IN THE CENTRAL INDIANA REGION, 1990-2000

This study examines a 44-county region in central Indiana to determine how closely public infrastructure and private built investment are linked, and whether the strength of the linkage is affected by differences in the planning environments of different jurisdictions. Two databases were developed to examine the nature of the relationship between planning tools and built investment. One dataset included indicators of the planning tools used by county jurisdictions and the second dataset included information on public and private construction activity obtained from a proprietary database. Findings indicate that counties with more planning tools (such as capital improvement plans, full-time planners and subdivision regulations) demonstrate a closer coordination between public infrastructure and private built investments. The relationship between public and private built investment appears to become stronger as the planning capacity of the county increases. Policy implications and directions for further research are suggested.
β2 subunit-containing nicotinic receptors mediate the enhancing effect of nicotine on trace cued fear conditioning in C57BL/6 mice

Rationale Previous research indicates that acute nicotine administration enhances the acquisition of contextual fear conditioning and trace cued fear conditioning. Pharmacological inhibition of α4β2 nicotinic acetylcholine receptors (nAChRs), but not α7 nAChRs, blocked the enhancing effect of nicotine on contextual fear conditioning. Similarly, genetic deletion of the β2 nAChR subunit but not the α7 nAChR subunit blocked the enhancing effect of nicotine on contextual fear conditioning.
V.L.A. observations of flare build-up in coronal loops

Abstract Very Large Array (V.L.A.) measurements at 20 cm wavelength map emission from coronal loops with second-of-arc angular resolution at time intervals as short as 3.3 seconds. The total intensity of the 20 cm emission describes the evolution and structure of the hot plasma that is detected by satellite X-ray observations of coronal loops. The circular polarization of the 20 cm emission describes the evolution, strength and structure of the coronal magnetic field. Preburst heating and magnetic changes that precede burst emission on time scales of between 1 and 30 minutes are discussed. Simultaneous 20 cm and soft X-ray observations indicate an electron temperature T e 2.5 × 10 7 K and electron density N e 10 10 cm −3 during preburst heating in a coronal loop that was also associated with twisting of the entire loop in space. We also discuss the successive triggering of bursts from adjacent coronal loops; highly polarized emission from the legs of loops with large intensity changes over a 32 MHz change in observing frequency; and apparent motions of hot plasma within coronal loops at velocities V > 2,000 kilometers per second.
Penetration of plasma across a magnetic field

Experiments were performed at the Nevada Terawatt Facility to investigate the plasma penetration across an externally applied magnetic field. In experiment, a short-pulse laser ablates a polyethylene laser target, producing a plasma which interacts with an external magnetic field. The mechanism which allows the plasma to penetrate the applied magnetic field in experiment will be discussed.
Dilemmas of Identity: Oral and Written Literacies in the Making of a Basic Writing Student

This article is a case study of an African American woman student returning to a basic-skills program in an inner-city community college. The student participates in a one-on-one writing conference in order to prepare a written essay. During a life-history telling by the student, the topic of her first paid job emerges. The task of transposing the telling into writing presents issues that are not covered in composition theory but that challenge accepted notions of schooled literacy.
Properties of dexsil 300 rubbers

Abstract : The physical and elastomeric properties of several DEXSIL 300 (10-SiB-3) samples were investigated. Modulus-temperature studies were used to determine the glass transition temperature, the melting temperature, and the oxidative crosslinking temperature. Stress relaxation in air at elevated temperatures was used to compare the oxidative stability of the various formulations. (Author)
Microwave-assisted metallurgy

Microwave heating has been extensively explored in various fields of materials processing. This technology exhibits unique characteristics including volumetric and selective heating, which eventually lead to many exceptional advantages over conventional processing methods including both energy and cost savings, improved product quality, faster processing and greater eco-friendliness, making microwave heating appropriate for applications in metallurgy. This paper presents a critical review on the use of microwave energy in metallurgy, with emphasis on both fundamentals of microwave heating and recent experimental efforts on extractive metallurgy via pyrometallurgical and/or hydrometallurgical routes. Applications to metallurgical processes for extraction of various metals, including heavy metals (Fe, Ni, Co, Cu, Pb and Zn), light metals (Al and Mg), rare metals (Ti, Mo, W and Re) and precious metals (Au, Ag and Pt), are reviewed and discussed.
Electron phonon relaxation dynamics of superconducting niobium as a function of temperature

The temperature dependence of the electron-phonon relaxation and of the electron-phonon coupling constant for a metal (Nb) has been determined for temperatures ranging from room temperature (292 K) to below superconducting temperatures (4.5 K). The measured rise time of the transmittance change decreases from 370 fs at 292 K to 205 fs at 4.5 K. The electron- phonon coupling constant decreases from 20 X 10 17 at 292 K to 0.5 X 10 17 W m -3 s -1 at 4.5 K. The cooling of the lattice after being heated by the pump pulse shows an increase in the cooling speed when the sample is below superconducting temperature. This faster decay may be attributed to the cooling due to formation of Cooper pairs.
Exercise therapy for older persons with cardiovascular disease.

Cardiac rehabilitation with exercise training after myocardial infarction in persons younger than 70 years has been found to cause a significant decrease in all-cause mortality, cardiovascular mortality, and fatal reinfarction, but no significant difference in nonfatal reinfarction. After myocardial infarction or coronary revascularization in older individuals, such programs significantly improve physical work capacity, body mass index, percent body fat, serum lipids, behavioral characteristics, and quality of life. Exercise modalities should include aerobic, resistance, and flexibility exercises. Less intense exercise of longer duration should be performed by older persons with coronary artery disease. Exercise training programs in patients with congestive heart failure produce significant improvement in peak oxygen consumption, exercise duration, and power output. The benefits of exercise training in patients with congestive heart failure may be due to an increase in cardiac output, an improvement in skeletal muscle metabolism, and an increase in peak blood flow to the exercising limb caused by a reduction in vascular resistance.
Quasi-linear boundary value problems with generalized nonlocal boundary conditions

Abstract We investigate a quasi-linear boundary value problem of the form − div ( α | ∇ u | p − 2 ∇ u ) = 0 involving a general boundary map and mixed Neumann boundary conditions on a bounded Lipschitz domain. We show existence, uniqueness, and Holder continuity of the weak solution of this mixed boundary value problem, and obtain maximum principles for this class of mixed equations. As a consequence, we obtain uniform continuity up to the boundary to solutions associated with a class of electrical models described by Maxwell’s equations with nonlocal boundary conditions. An extension to boundary value problems with generalized nonlocal Robin boundary conditions is also achieved.
Radiance-irradiance inversion algorithm for estimating the absorption and backscattering coefficients of natural waters: vertically stratified water bodies.

A full multiple-scattering algorithm for inverting profiles of the upwelling and downwelling irradiances to yield profiles of the absorption and backscattering coefficients in a vertically stratified water body is described and tested with simulated data. The algorithm does not require knowledge of the scattering phase function of the medium. The results are better the closer the phase function assumed in the retrievals is to the true phase function, although excellent retrievals of the absorption coefficient can still be obtained with an inaccurate phase function. Simulations show that the algorithm is capable of determining the vertical structure of a stratified water body and usually provides the absorption coefficient profile with an error ≲2% and the backscattering coefficient profile with an error ≲10%, as long as the spacing between pseudodata samples is sufficiently small that the necessary derivatives of the irradiances can be accurately computed. The performance is only slightly degraded when the upwelling radiance (nadir viewing) is substituted for the upwelling irradiance.