cssi/SciSciGPT-SciSciNet huggingface dataset:
The Umbral Calculus

In this chapter, we give a brief introduction to a relatively new subject, called the umbral calculus. This is an algebraic theory used to study certain types of polynomial functions that play an important role in applied mathematics. We give only a brief introduction to the subject — emphasizing the algebraic aspects rather than the applications. For more on the umbral calculus, we suggest The Umbral Calculus, by Roman [1984].
Automated hypothesis generation based on mining scientific literature

Keeping up with the ever-expanding flow of data and publications is untenable and poses a fundamental bottleneck to scientific progress. Current search technologies typically find many relevant documents, but they do not extract and organize the information content of these documents or suggest new scientific hypotheses based on this organized content. We present an initial case study on KnIT, a prototype system that mines the information contained in the scientific literature, represents it explicitly in a queriable network, and then further reasons upon these data to generate novel and experimentally testable hypotheses. KnIT combines entity detection with neighbor-text feature analysis and with graph-based diffusion of information to identify potential new properties of entities that are strongly implied by existing relationships. We discuss a successful application of our approach that mines the published literature to identify new protein kinases that phosphorylate the protein tumor suppressor p53. Retrospective analysis demonstrates the accuracy of this approach and ongoing laboratory experiments suggest that kinases identified by our system may indeed phosphorylate p53. These results establish proof of principle for automated hypothesis generation and discovery based on text mining of the scientific literature.
On the early-time chemistry in dark clouds

Context. Agreement between observed and calculated abundances of some molecules in dark clouds is improved when the model gas retains some memory of the assumed initial conditions. Aims. We assess the relevance of commonly-assumed intitial conditions giving rise to so-called early-time chemistry in models of dark cloud chemistry. Methods. Initial conditions for models of dark cloud chemistry are compared with conditions known to exist in the H2-bearing diffuse gas whose evolution they are intended to represent. Results. The initial conditions assumed for dark cloud chemistry differ in at least five important regards from those of H2-bearing diffuse gas. Models typically assume: absolute purity of H2; absence of polycyclic aromatic hydrocarbons; two times smaller gasphase abundance of C, N, and O; near-absence of sulfur and some other easily-ionized metals; total absence of the molecules which accompany the presence of H2 in diffuse gas, for instance, OH, CH, C2H, HCO + . Conclusions. Initial conditions commonly assumed for dark cloud chemical models should be reconsidered and mechanisms for the chemical evolution from diffuse to dark gas should be included in model calculations.
ON THE COMPRESSION WAVE GENERATED WHEN A HIGH-SPEED TRAIN ENTERS A TUNNEL WITH A FLARED PORTAL

Abstract An analysis is made of the compression wave generated when a high-speed train enters a tunnel with a flared portal. Nonlinear steepening of the wavefront in a very long tunnel is responsible for an intense, environmentally harmful, micro-pressure wave , which propagates as a pulse from the distant tunnel exit when the compression wave arrives, with amplitude proportional to the maximum gradient in the compression wavefront. The compression wave profile can be determined analytically for train Mach numbers M satisfying M2⪡1, by regarding the local flow near the tunnel mouth during train entry as incompressible . In this paper, the influence of tunnel portal flaring on the initial thickness of the compression wave is examined first in this limit. The shape of the flared portal is “optimal” when the pressure gradient across the front is constant and an overall minimum, so that the pressure in the wavefront increases linearly . This linear behaviour is shown to occur for a flared portal extending a distance l into the tunnel from the entrance plane (x=0) only when the tunnel cross-sectional area S (x) satisfies S ( x ) A = 1 [ A / A E −( x /l)(1− A / A E )] , −l where x increases negatively with distance into the tunnel, A is the cross-sectional area in the uniform section of the tunnel (x A Eis the tunnel entrance cross-section. The optimum portal is achieved by adjusting the value of A / A Eto make the pressure gradient continuous, and a formula is derived for this ratio for tunnels of semi-circular cross-section. For optimal flaring, the pressure rises linearly as the front of the train traverses the flared section of length l, and the thickness of the compression wavefront ∼l/M . A formula is proposed for extrapolating these predictions to train Mach numbers as large as 0·4, which is expected to be typical of future high-speed rail operations. It is validated for the special case of a circular cylindrical tunnel, for which an exact solution is known for arbitrary subsonic Mach numbers, and by comparison with scale model experiments using trains of various nose profiles.
Micro Optical Spatial and Spectral Elements (MOSSE)

Interference transmission filters that have a defect layer incorporated photonic crystal structure provide a narrow transmission notch within a wide stop band. The location and width of transmission notch can be tuned by changing the thickness of the defect layer. In this paper, we propose and implement interference filters with defect layers patterned with diffractive optical elements. The spectral transmission is a function of the local defect layer thickness while the spatial transmission follows contours of equal optical thickness. The novel devices have multiplexed spectral and spatial transmission characteristics. Alternating layers of silicon oxide (SiOx) and silicon nitride (SixNy) were grown onto a clean silicon substrate using plasma enhanced chemical vapor deposition (PECVD). A thick defect layer of SiOx was grown and the wafer was removed from the growth chamber. The wafer was then patterned with charge 2, 8-level vortex structures on a GCA 6300 g-line stepper tool. The devices were interrogated with a collimated beam from a tunable laser source that operates from 1520 nm to 1630 nm. The spectral transmission was measured by separately illuminating each level of diffractive element and the spatial transmission was imaged on to a CCD camera. Spectral transmission peaks whose location varies as a function of level height were obtained. The spatial transmission profiles consist of triangular zones with wavelength dependent orientation. The elements have potential applications in hyper spectral imaging, pupil filtering, and engineered illumination systems.
A minimum mechanism for Na+−Ca++ exchange: Net and unidirectional Ca++ fluxes as functions of ion composition and membrane potential

Both simultaneous and consecutive mechanisms for Na+−Ca++ exchange are formulated and the associated systems of steady-state equations are solved numerically, and the net and unidirectional Ca++ fluxes computed for a variety of ionic and electrical boundary conditions. A simultaneous mechanism is shown to be consistent with a broad range of experimental data from the squid giant axon, cardiac muscle and isolated sarcolemmal vesicles. In this mechanism, random binding of three Na+ ions and one Ca++ on apposing sides of a membrane are required before a conformational change can occur, translocating the binding sites to the opposite sides of the membranes. A similar (return) translocation step is also permitted if all the sites are empty. None of the other states of binding can undergo such translocating conformational changes. The resulting reaction scheme has 22 reaction steps involving 16 ion-binding intermediates. The voltage dependence of the equilibrium constant for the overall reaction, required by the 3∶1 Na+∶Ca++ stoichiometry was obtained by multiplying and dividing, respectively, the forward and reverse rate constants of one of the translocational steps by exp(−FV/2RT). With reasonable values for the membrane density of the enzyme (≈120 sites μm2) and an upper limit for the rate constants of both translocational steps of 105·sec−1, satisfactory behavior was obtainable with identical binding constants for Ca++ on the two sides of the membrane (106m−1), similar symmetry also being assumed for the Na+ binding constant (12 to 60m−1). Introduction of order into the ion-binding process eliminates behavior that is consistent with experimental findings.
Fasting and postprandial markers of inflammation in lean and overweight children

Background: Overweight children have greater circulating concentrations of markers of inflammation (MOI) than do lean children. Whether adiposity influences the postprandial MOI response is unknown. Objective: We aimed to evaluate the relations of fasting and postprandial MOI with total and regional adiposity and insulin sensitivity in children. Design: Fifty-nine children aged 7–12 y were assessed for C-reactive protein (CRP), interleukin-6 (IL-6), and soluble tumor necrosis factor receptor-2 (sTNF-R2) in the fasted state and after a mixed meal. Insulin sensitivity, body composition, and abdominal adipose tissue distribution were assessed with a frequently sampled intravenous-glucose-tolerance test, dual-energy X-ray absorptiometry, and computed tomography, respectively. Results: Central adipose measures were not independently associated with fasting MOI, although they were independently inversely associated with the postprandial sTNF-R2 response (r = −0.30 to −0.37, P = 0.02–0.006). The inverse association between intraabdominal adipose tissue and the postprandial CRP response was nearly significant (r = −0.27, P = 0.05). Insulin sensitivity was not associated with fasting or postprandial CRP or sTNF-R2; however, there was a positive relation between insulin sensitivity and fasting IL-6 (r = 0.27, P = 0.03), which was attenuated after adjustment for lean body mass (r = 0.25, P = 0.08). Conclusions: Excess adiposity is associated with both fasting and postprandial MOI. The postprandial MOI response may be influenced by central adiposity in children. The positive association of insulin sensitivity with IL-6 warrants further study.
False aneuploidy in flow cytometric DNA analysis of paraffin embedded tissue: Effects of carnoy's fixation

False aneuploidy was detected on flow cytometric DNA analysis of paraffin embedded axillary lymph nodes negative for tumor. It was hypothesized that “clearing” of axillary fat in Carnoy's solution to facilitate lymph node dissection might be responsible for false aneuploidy. Various tissues fixed overnight in Carnoy's were compared to formalin fixed paraffin embedded controls. Under these conditions no false aneuploid peaks were detected, but Carnoy's fixation did shift the G0/G1 histogram peak to the left, increase the G0/G1 CV and increase the S phase fraction relative to formalin fixed controls. It was then hypothesized that partial fixation of nodes in Carnoy's followed by formalin fixation might result in false aneuploid peaks. Twenty-two lymph nodes were partially fixed in Carnoy's for periods ranging from 5 to 60 min followed by complete fixation in formalin. Seven of these nodes did show false aneuploid peaks. By contrast, no aneuploidy was detected in formalin fixed controls. It was concluded that tissues in contact with Carnoy's solution may be a source of false aneuploidy and/or false elevation of S phase fraction. This reinforces the need for matched negative tissue controls for DNA analysis of paraffin embedded specimens whenever possible. © 1993 Wiley-Liss, Inc.
Organization, sequence and regulation of expression of the murine Hoxa-7 gene.

Abstract The genomic sequence of Hoxa-7 (encoding the HOXa-7 homeobox protein), including the coding region (0.7 kb), flanked by a 5′-upstream region (2.8 kb), a 3′-downstream region (1 kb) and interrupted by an intron (995 bp), was determined. Northern blot analysis indicated the transcript size of Hoxa-7 to be 2.1-2.4 kb. Reverse transcription-PCR and primer extension analysis established the 5′-boundary of the mRNA to be in the region 1166 nt upstream from the start codon. Transient transfection of various Hoxa-7::cat constructs in NIH 3T3 cells was used to characterize the transcriptional activity of the 5'-flanking region of the gene. Constructs containing 544, 274 and 71 bp of the region upstream from the transcription start point (tsp) exhibited 78, 203 and 407%, respectively, of the activity shown by a control construct containing 739 bp of the upstream region. These data suggested the presence of negative regulatory elements in the region from 544 to 71 bp upstream from the tsp.
Nuclear Magnetic Susceptibility of Solid He 3 Cooled by Compression from the Liquid Phase

Using the cooling power of the adiabatic solidification of ${\mathrm{He}}^{3}$, we have reached temperatures near 2 mK and have measured the temperature dependence of the susceptibility of solid ${\mathrm{He}}^{3}$ down to 6 mK. The magnetic ordering is antiferromagnetic, with a Weiss $\ensuremath{\theta}=3.0\ifmmode\pm\else\textpm\fi{}0.3$ mK corresponding to a N\'eel temperature of 2.1 mK for bcc ${\mathrm{He}}^{3}$ at 34 atm.
Nilvadipine antagonizes both Aβ vasoactivity in isolated arteries, and the reduced cerebral blood flow in APPsw transgenic mice

The development of Alzheimer's disease (AD) is generally thought to correlate with cerebral accumulation of Aβ. It has previously been shown that Aβ peptides enhance vasoconstriction in isolated arteries and oppose certain vasorelaxants. Moreover, exogenous application of Aβ peptides causes cerebral vasoconstriction in rodents and in transgenic mouse models of AD that overexpress Aβ there is reduced cerebral blood flow. In the present study, we investigated the effect of nilvadipine, a dihydropyridine-type calcium channel blocker, on Aβ induced vasoconstriction in isolated arteries and in vivo on cerebral blood flow (CBF) of an AD transgenic mouse model overexpressing Aβ (Tg APPsw line 2576). Nilvadipine completely inhibited the vasoactivity elicited by Aβ in rat aortae and in human middle cerebral arteries. The effect of a short treatment duration (2 weeks) with nilvadipine on regional CBF was investigated in 13-month-old Tg APPsw mice and control littermates using a laser Doppler imager. Additionally, CBF was also measured in 20-month-old Tg APPsw mice and control littermates that were chronically treated with nilvadipine for 7 months. Untreated Tg APPsw mice showed a reduction of regional CBF compared to their untreated control littermates. Nilvadipine restored cortical perfusion levels in Tg APPsw to values similar to those observed in control littermates without notably affecting the CBF of control mice. All together, these data suggest that nilvadipine might be useful for the treatment of oligemia associated with AD.
Status of an induction-accelerator-driven, high-power microwave generator at Livermore

The authors are testing an enhanced version of the Choppertron, a high-power rf generator which shows great promise of achieving greater than 400 MW of output power at 11.4 GHz with stable phase and amplitude. This version of the Choppertron is driven by a 5-MeV, 1-kA induction accelerator beam. Modifications to the original Choppertron included aggressive suppression of high order modes in the two output structures, lengthening of the modulation section to match for higher beam energy, and improved efficiency. Final results of the original Choppertron experiment, status of the ongoing experiment and planned experiments for the next year are presented. The motivation of the research program at the LLNL Microwave Source Facility is to develop microwave sources which could be suitable drivers for a future TeV linear e{sup +}e{sup {minus}} collider.
Congenital diaphragmatic hernia.

Background—congenital diaphragmatic hernia (CDH) has a reported incidence of 1 in 2500 to 1 in 4000 live births with an estimated 30 % spontaneous abortion rate.
The Degradation of Phosphoenolpyruvate Carboxykinase (GTP) mRNA Is Regulated by Cyclic AMP But Not by Dexamethasone

Abstract The relationship between the control by cAMP of phosphoenolpyruvate carboxykinase (GTP) mRNA synthesis and breakdown was examined. The half-life of phosphoenolpyruvate carboxykinase mRNA was estimated from its decay rate in cells exposed to insulin (a specific inhibitor of phosphoenolpyruvate carboxykinase gene transcription) in the presence or absence of 8-chlorophenylthio-cyclic AMP after high levels of the mRNA had been induced by the cyclic nucleotide. The mRNA decayed with a half-life of 300-350 mm in cells treated with 8-chlorophenylthio-cyclic AMP and insulin whereas the T1/2 was 30-40 min in cells exposed to insulin alone. Similar results were obtained when 5,6-dichloro-1-β-ribofuranosyl-benzimidazole, a general inhibitor of mRNA synthesis, was used. The mRNA decayed at comparable rates in cells treated with insulin or 5,6-dichloro-1-β-ribofuranosyl-benzimidazole or in cells exposed to insulin-free medium after withdrawal of the inducer of gene transcription. These results suggest that insulin does not modulate phosphoenolpyruvate carboxykinase mRNA breakdown. 8-Chlorophenylthio-cyclic AMP reversed the rapid decay of the mRNA in cells preexposed to insulin for 1 h even when over 60% of the mRNA had been degraded. In contrast to cAMP, no alterations in the rate of phosphoenolpyruvate carboxykinase mRNA decay were noted in cells exposed to the synthetic glucocorticoid dexamethasone. The half-life of phosphoenolpyruvate carboxykinase mRNA, expressed from a hybrid gene driven by the non-cAMP regulated promoter of the mouse metallothionein-I gene, was also increased in cells treated with 8-chlorophenylthio-cyclic AMP. These results suggest that the control by cAMP of phosphoenolpyruvate carboxykinase mRNA breakdown is accomplished by a rapid mechanism which is independent of the induction of gene transcription.
Interference in a typeface variant of the Stroop test

Ss were asked to name the typeface in which a printed item appeared in a discrete trial variant of the Stroop color-word test. Two kinds of items were used: (a) typeface names appearing in antagonistic typefaces, e.g., the word SCRIPT printed in bold type; and (b) nonsense strings constructed by jumbling; the letters in a typeface name, e.g., PSRTCI printed in bold type. Typeface-naming latencies were found to be significantly longer for items of the first kind. Examination of the distributions of individual trial latencies for the two kinds of items indicated that modification of Morton’s (1969) account of the Stroop test is required.
The Anomalous Behavior of Silicon During Nanoindentation

Two separate phenomena occur during the low-load indentation of silicon which make its behavior distinctly different from that of most materials. First, silicon is one of only a very few materials whose hardness exceeds the pressure needed to transform it to a denser crystalline (or amorphous) form, and because of this, a reversible, pressure-induced phase transformation occurs during indentation. The transformation enhances the electrical conductivity of the material and creates a region around the indenter which flows like a soft metal. Second, silicon cracks when indented by a Berkovich or Vickers indenter at loads of less than 100 mN, i.e., loads typically used in nanoindentation experiments. These two phenomena, which account for a number of unusual features in the indentation load-displacement behavior, are documented and discussed.
Force associated with the Temperature Gradient on a Small Particle suspended in a Plasma

Mason and Chapman1 have shown that the motion of small particles in a non-uniform un-ionized gas may be described through the Chapman–Enskog theory by treating the particles as large molecules. Their kinetic theory calculations agree with results obtained by previous investigators2–4, who used free-molecule momentum transfer calculations, for all cases except when a temperature gradient is present.
NAPSS—a numerical analysis problem-solving system

It has long been a recognized goal of computer programming technology to permit problems to be stated in languages appropriate to the fields in which the problems exist, and to provide for the solution of such problems as stated without requiring the services of specially trained programmers and analysts. Systems that provide these capabilities are “problem solving systems.” Their languages are problem-oriented languages. Systems of this type have been proposed and developed in a number of areas of engineering and design. Examples are the COGO system developed at MIT 1 and the DACS system developed by General Motors 2. At Purdue University during the past year we have been working on a design for a Numerical Analysis Problem Solving System (NAPSS). This paper discusses some of the features of the language and system design, and an approach through the development of so-called polyalgorithms to the design of the numerical analysis packages that are the essential elements of the problem solving system.
Gα Protein Selectivity Determinant Specified by a Viral Chemokine Receptor-Conserved Region in the C Tail of the Human Herpesvirus 8 G Protein-Coupled Receptor

The viral G-protein coupled receptor (vGPCR) specified by human herpesvirus 8 (HHV-8) open reading frame 74 (ORF74) is a ligand-independent chemokine receptor that has structural and functional homologues among other characterized gammaherpesviruses and related receptors in the betaherpesviruses. Sequence comparisons of the gammaherpesvirus vGPCRs revealed a highly conserved region in the C tail, just distal to the seventh transmembrane domain. Mutagenesis of the corresponding codons of HHV-8 ORF74 was carried out to provide C-tail-altered proteins for functional analyses. By measuring receptor-activated vascular endothelial growth factor promoter induction and NF-kappaB, mitogen-activated protein kinase, and Ca(2+) signaling, we found that while some altered receptors showed general signaling deficiencies, others had distinguishable activation profiles, suggestive of selective Galpha protein coupling. This was supported by the finding that vGPCR and representative functionally altered variants, vGPCR.8 (R322W) and vGPCR.15 (M325S), were affected differently by inhibitors of Galpha(i) (pertussis toxin), protein kinase C (GF109203X), and phosphatidylinositol 3-kinase (wortmannin). Consistent with the signaling data, [(35)S]GTPgammaS incorporation assays revealed preferential coupling of vGPCR.15 to Galpha(q) and an inability of vGPCR.8 to couple functionally to Galpha(q). However, both variants, wild-type vGPCR, and a C-tail deletion version of the receptor were equally able to associate physically with Galpha(q). Combined, our data demonstrate that HHV-8 vGPCR contains discrete sites of Galpha interaction and that receptor residues in the proximal region of the cytoplasmic tail are determinants of Galpha protein coupling specificity.
Export performance of major cultured shrimp producers in the Japanese and US markets

Increase in shrimp farming was stimulated by growth in world market for high-value shrimp products in the 1980s. The major cultured shrimp producers are located in Asia-Pacific and Latin American regions. The revealed comparative advantage (RCA) method is used to provide insights into the export performance of nine selected shrimp producers in the Japan and United States markets, separately. Shrimp is marketed in a wide variety of product forms, and prices vary according to various product attributes including species, size, taste, quality and origin. The results show that vertical product differentiation concerning different varieties of a good in terms of both quality and price plays an important role on the relative export competition of shrimp products among major shrimp-exporting countries. As a result of the geographical advantage, Asia-Pacific producers enjoy comparative advantage in the Japanese imported shrimp market. Joint ventures with the United States provide great benefits to Ecuador and Mexico in exporting fresh shrimp into the United States market.
An outage-aware power saving Cooperative Routing algorithm in wireless networks

In this paper emphasizing the relation between outage and power, we propose a novel cooperative routing algorithm, called Outage-aware K-shortest paths Cooperative Routing (OKCR), which minimizes the transmitted power while exploiting the merit of cooperative communication. The OKCR algorithm (i.e., inherently based on Yen's Kshortest paths algorithm) finds the best route between the source and the destination considering particular outage probability as its constraint. The proposed algorithm nominates k different optimum routes and then selects the best possible relay in each route on the basis of performance analysis. Simulation results show that this strategy enhances power-efficiency in comparison to non-cooperative and other existing cooperative algorithms investigated in the literature by more than 50%.
The Role of the SLP in Autism Spectrum Disorder Screening and Assessment

Abstract Recent prevalence estimates for autism have been alarming as a function of the notable increase. Speech-language pathologists play a critical role in screening, assessment and intervention for children with autism. This article reviews signs that may be indicative of autism at different stages of language development, and discusses the importance of several psychometric properties—sensitivity and specificity—in utilizing screening measures for children with autism. Critical components of assessment for children with autism are reviewed. This article concludes with examples of intervention targets for children with ASD at various levels of language development.
Statistical study of multiresolutional target tracking

This paper addresses the spatial domain multiresolutional target tracking, featuring the statistics of the decomposed measurements.
Where Are the Muslim Moderates

The drama between the secularist legacy of Ataturk and the popular surge of Islamist-rooted politics continues in Turkey, centered on the debate over the headscarf. Is it a sign of religious reaction, or a sign of non-Western modernization that will ensure higher education for Muslim women? We represent here all sides of the debate. Elsewhere in the Muslim world are the reformers and critics listening to each other, or impeding progress with a blame game? Europe's most controversial figures in this debate—Ayaan Hirsi Ali and Tariq Ramadan—engage here.
Scan impedance of RSW microstrip antennas in a finite array

Scan impedances of finite reduced surface wave (RSW) arrays are studied. Center element scan impedances of linear arrays and two-dimensional (2-D) square lattice arrays are calculated and compared with those of conventional microstrip arrays. Results show that compared with conventional microstrip arrays, broadside scan impedance of RSW arrays has less variation and converges much faster when the array size increases. Scan performance of the linear and 2-D square lattice RSW arrays are also studied. Results show that the RSW array can avoid the scan blindness (when the array spacing is greater than 0.5/spl lambda//sub 0/) and the scan impedance has much less variation than that of conventional microstrip array with the same array spacing. However, due to the size limitation of RSW elements, the grating lobes cannot be avoided. Hence, the scan region is limited to about 20/spl deg/ (with 0.75/spl lambda//sub 0/ array spacing). Compared with conventional microstrip arrays with 0.5/spl lambda//sub 0/ array spacing, the results show no favor to RSW arrays.
Are HO radicals produced in the reaction of O(3P) with 1-C4H8?

The reaction of O(3P) with 1-C4H8 was examined in the presence of CO which scavenges HO radicals to produce CO2. From the CO2 quantum yield, an upper limit to the efficiency of HO production in the reaction of O(3P) with 1-C4H8 was found to be 0.020 at both 298 and 473 K.
Sad Heart From No SOD

The superoxide dismutases (SODs), which catalyze the dismutation of 2 superoxide anions to hydrogen peroxide and oxygen, represent major antioxidant mechanisms in single-cell organisms, plants, bacteria and eukaryotes. In mammalian cells, there are 3 forms of SOD that include the mitochondrial manganese SOD (MnSOD or SOD2), the cytoplasmic SOD that is a copper/zinc-containing enzyme (Cu/Zn SOD or SOD1), and an extracellular SOD that is also a copper/zinc-containing enzyme (ecSOD or SOD3). The ecSOD is unique in that it is actively secreted via the trans -Golgi network and binds to glycosaminoglycans in the vascular extracellular matrix and to the extracellular protein fibrillin 5.1 In most tissues, the amount of ecSOD is very small, on the order of 1% to 5% of the total SOD. In contrast, blood vessels, the lung, and to a lesser extent, the heart contain substantial amounts of this enzyme. The ecSOD is therefore of particular interest to investigators interested in cardiovascular and pulmonary biology. Overexpression of ecSOD protects mice against lung damage, and mice lacking ecSOD are predisposed to lung injury caused by hyperoxia. Between 30% and 50% of the total SOD in blood vessels is in this extracellular form, and mice lacking this enzyme have vascular dysfunction and are predisposed to hypertension.2 In cardiovascular tissues and, likely the lung, an important role of the SODs is to protect NO against oxidative inactivation by superoxide. Both NO and superoxide are free radicals with unpaired electrons in their outer orbitals and react with one another in a diffusion-limited fashion. Studies in which the Cu/ZnSODs (SOD1 and SOD3) have been pharmacologically inhibited have shown that NO cannot be released from the endothelium without being oxidatively degraded.3 Thus, these enzymes play a role in promoting vasodilatation and sustaining the protective roles of NO in the vascular wall. …
Variable and Constant Volume Operation in Telephone Communication System

The objective in voice communication circuit design is to deliver adequate acoustic power to the listener's ear in the presence of incidental circuit noise and thus permit satisfactory conversation between the talker and listener. The ranges of volumes applied to the circuit and the range received at the listener's ear in general are the same. The average received volume is essentially the average transmitted volume displaced by the net loss of the connecting circuit. The circuits between the talker and listener must carry the maximum volume without serious overloading. The minimum volume talker must be maintained at a high enough volume so that the listener will have an adequate signal-to-noise ratio to carry on a satisfactory conversation. The signal-to-noise for higher volume talkers will be greater by the difference in volume, which means the circuit is better than it needs to be for satisfactory conversation. It is suggested that the volume range be reduced by applying volume regulators to each long distance circuit. In addition, the peak-to-rms ratio of the signal is reduced by applying peak limiting. The average volume transmitted is raised to obtain the same overload expectancy. The increased signal power improves the signal-to-noise ratio. The improvement can be used to increase the signal-to-noise ratios in marginal circuits, or to reduce the cost of providing the service in new installations. It is shown that constant volume regulators applied to the present long haul plant will improve the poorer 10 per cent of the circuits by 15 dB or more.
Efficient Atmospheric Cleansing of Oxidized Organic Trace Gases by Vegetation

The biosphere is the major source and sink of nonmethane volatile organic compounds (VOCs) in the atmosphere. Gas-phase chemical reactions initiate the removal of these compounds from the atmosphere, which ultimately proceeds via deposition at the surface or direct oxidation to carbon monoxide or carbon dioxide. We performed ecosystem-scale flux measurements that show that the removal of oxygenated VOC via dry deposition is substantially larger than is currently assumed for deciduous ecosystems. Laboratory experiments indicate efficient enzymatic conversion and potential up-regulation of various stress-related genes, leading to enhanced uptake rates as a response to ozone and methyl vinyl ketone exposure or mechanical wounding. A revised scheme for the uptake of oxygenated VOCs, incorporated into a global chemistry-transport model, predicts appreciable regional changes in annual dry deposition fluxes.
Weighting matrix design for robust monotonic convergence in Norm Optimal iterative learning control

In this paper we examine the robustness of norm optimal ILC with quadratic cost criterion for discrete-time, linear time-invariant, single-input single-output systems. A bounded multiplicative uncertainty model is used to describe the uncertain system and a sufficient condition for robust monotonic convergence is developed. We find that, for sufficiently large uncertainty, the performance weighting can not be selected arbitrarily large, and thus overall performance is limited. To maximize available performance, a time-frequency design methodology is presented to shape the weighting matrix based on the initial tracking error. The design is applied to a nanopositioning system and simulation results are presented.
Functional reconstitution of SdcS, a Na+-coupled dicarboxylate carrier protein from Staphylococcus aureus.

ABSTRACT In Staphylococcus aureus, the transport of dicarboxylates is mediated in part by the Na+-linked carrier protein SdcS. This transporter is a member of the divalent-anion/Na+ symporter (DASS) family, a group that includes the mammalian Na+/dicarboxylate cotransporters NaDC1 and NaDC3. In earlier work, we cloned and expressed SdcS in Escherichia coli and found it to have transport properties similar to those of its eukaryotic counterparts (J. A. Hall and A. M. Pajor, J. Bacteriol. 187:5189-5194, 2005). Here, we report the partial purification and subsequent reconstitution of functional SdcS into liposomes. These proteoliposomes exhibited succinate counterflow activity, as well as Na+ electrochemical-gradient-driven transport. Examination of substrate specificity indicated that the minimal requirement necessary for transport was a four-carbon terminal dicarboxylate backbone and that productive substrate-transporter interaction was sensitive to substitutions at the substrate C-2 and C-3 positions. Further analysis established that SdcS facilitates an electroneutral symport reaction having a 2:1 cation/dicarboxylate ratio. This study represents the first characterization of a reconstituted Na+-coupled DASS family member, thus providing an effective method to evaluate functional, as well as structural, aspects of DASS transporters in a system free of the complexities and constraints associated with native membrane environments.
Presenting Symptoms of Pediatric Brain Tumors

The presenting features of brain tumors in 200 children diagnosed between 1988 and 2001 were determined by retrospective chart review at the pediatric and neurosurgical services of the Wessex Neurology Centre and Southampton General Hospital, UK.
Response of peak electron densities in the martian ionosphere to day-to-day changes in solar flux due to solar rotation

Abstract Photochemical Chapman theory predicts that the square of peak electron density, N m , in the dayside ionosphere of Mars is proportional to the cosine of solar zenith angle. We use Mars Global Surveyor Radio Science profiles of electron density to demonstrate that this relationship is generally satisfied and that positive or negative residuals between observed and predicted values of N m 2 are caused by periods of relatively high or low solar flux, respectively. Understanding the response of the martian ionosphere to changes in solar flux requires simultaneous observations of the martian ionosphere and of solar flux at Mars, but solar flux measurements are only available at Earth. Since the Sun's output varies both in time and with solar latitude and longitude, solar flux at Mars is not simply related to solar flux at Earth by an inverse-square law. We hypothesize that, when corrected for differing distances from the Sun, solar fluxes at Mars and Earth are identical when shifted in time by the interval necessary for the Sun to rotate through the Earth–Sun–Mars angle. We perform four case studies that quantitatively compare time series of N m at Mars to time series of solar flux at Earth and find that our hypothesis is satisfied in the three of them that used ionospheric data from the northern hemisphere. We define a solar flux proxy at Mars based upon the E 10.7 proxy for solar flux at Earth and use our best case study to derive an equation that relates N m to this proxy. We discuss how the ionosphere of Mars can be used to infer the presence of solar active regions not facing the Earth. Our fourth case study uses ionospheric observations from the southern hemisphere at latitudes where there are strong crustal magnetic anomalies. These profiles do not have Chapman-like shapes, unlike those of the other three case studies. We split this set of measurements into two subsets, corresponding to whether or not they were made at longitudes with strong crustal magnetic anomalies. Neither subset shows N m responding to changes in solar flux in the manner that we observe in the three other case studies. We find many similarities in ionospheric responses to short-term and long-term changes in solar flux for Venus, Earth, and Mars. We consider the implications of our results for different parametric equations that have been published describing this response.
Effect of resin components on the degradation of guayule rubber

All natural rubbers are likely to contain some long chain fatty acids or their esters. The individual effect of the four C18 fatty acids (stearic, oleic, linoleic, and linolenic acid) present in the guayule resin on the degradation of guayule rubber has been investigated concurrently by stress–relaxation of radiation cured rubber networks and by gel permeation chromatography studies on the raw rubber in the temperature zone 70–125°C. C18 unsaturated fatty acids enhance the degradation of rubber several fold. The rate of degradation follows the order: rubber ≤ rubber + stearic acid < rubber + oleic acid < rubber + linoleic acid < rubber + linolenic acid. The thermal degradation is slower than the thermooxidative. The rate of degradation monotonically increased with the number of conjugated double bonds and is first order with respect to acid concentration. The activation energy for the chain scission for both thermal and thermooxidative degradation has been found to be 95 ± 10 kJ/mol. The mechanism of degradation of guayule rubber in the presence of fatty acids is discussed.
Effect of folic acid and leucovorin on synthesis of the labile methyl group from methanol in the rat.

Previous experiments from this Laboratory with C4-methanol demonstrated that the carbon of methanol becomes incorporated into the methyl group of choline in the rat (1). This observation has been confirmed by Arnstein (2). In a subsequent investigation carried out in this Laboratory with methanol doubly labeled in the methyl group with deuterium and C14, it was found that less than one-third of the hydrogens accompanied each carbon of the methanol when it made its appearance in the methyl group of choline (3). It was concluded that the methanol was being utilized, at least in large part, for the synthesis of a newly formed methyl group within the animal body, presumably through oxidation and subsequent reduction. The present communication describes experiments undertaken with labeled methanol to determine whether folic acid’ or its derivative, a synthetic preparation, Leucovorin (5), having Leuconostoc citrovorum factor (LCF) activity, had any effect on the utilization of methanol for methyl synthesis. The original dietary work of Bennett (6) and the recent contributions from various investigators have indicated that folic acid is in some way involved in labile methyl metabolism.
Stability of unused reconstituted bortezomib in original manufacturer vials

Background. Bortezomib is a modified dipeptidyl boronic acid analogue used to treat multiple myeloma, mantle cell lymphoma, and, more recently, renal transplantation graft rejection. As per manufacturer recommendations, bortezomib is to be administered within 8h of preparation or may be stored for up to 8h in the vial or a syringe following reconstitution. Preserving unused reconstituted bortezomib beyond these 8h may allow for cost savings. This study aims to examine the stability of unused reconstituted bortezomib when stored at 4 � C for up to 15 days. Methods. Using an LC-MS/MS assay, the concentration of reconstituted bortezomib was measured at predetermined time points following storage at 4 � C in the manufacturer vial. Percent bortezomib remaining at a time point was calculated versus initial bortezomib concentration. Results. The concentrations of bortezomib were found to be 51.93ng/mL � 4.60 after 1 day of storage, 57.40ng/ mL � 4.77 after 8 days of storage, and 49.43ng/mL � 2.85 after 15 days of storage. The percent of bortezomib remaining was 110.53% and 95.19% after 8 days and 15 days, respectively. Conclusion. Unused reconstituted bortezomib is stable for up to 15 days stored at 4 � C in the original manufacturer vial. Such use of bortezomib may improve cost efficiency by reducing bortezomib waste.
The effect of estradiol replacement therapy on early pregnant luteectomized patients

Abstract Since in early pregnant patients luteectomy provoked not only progesterone (P) but also estradiol-17β (E 2 ) deficiency, the unlikely possibility that the observed 1,2 physiologic and clinical consequences of the suspension of luteal function resulted from E 2 deficiency had to be examined. Of the 10 luteectomized early pregnant patients studied, uterine activity and reactivity evolved and abortion occurred in those 7 gravidas who had only 18.9 ± 1.9 days of amenorrhea (after the missed menstrual period) and whose plasma P levels decreased continuously. These 7 patients aborted despite the sustenance of preoperative E 2 levels in 6 gravidas by a daily dose of 1 mg. and the increase in E 2 levels in 1 woman by 5 mg. of estradiol bensoate, intramuscularly in oil. In the remaining 3 patients who were luteectomized after 29.7 ± 2.7 days of amenorrhea, plasma P decreased only slightly and not continuously. These 3 patients whose E 2 levels were also sustained exogenously did not abort during 7 days of observation. It is concluded that luteectomy-induced E 2 withdrawal does not but P withdrawal does contribute to the evolution of uterine activity and abortion.
High-field fourier transform ion cyclotron resonance mass spectrometry for simultaneous trapping and gas-phase hydrogen/deuterium exchange of peptide ions

Gas-phase hydrogen/deuterium exchange of D2O with [M+H]+ ions of angiotensin II, angiotensin I, [Sar1]-angiotensin II, bradykinin, des-Arg1-bradykinin, des-Arg9-bradykinin, luteinizing hormone releasing hormone (LH-RH), and substance P has been examined by Fourier transform ion cyclotron resonance mass spectrometry at 9.4 tesla. Because the FTICR dynamic range increases quadratically with magnetic field, parent ions from a mixture of several peptides may be confined simultaneously for long periods at high pressure (e. g., 1 h at 1×10−5 torr) without quadrupolar axialization (and its attendant ion heating), for faster data acquisition and better controlled comparisons between different peptides. A high magnetic field also facilitates stored waveform inverse Fourier transform (SWIFT) isolation of monoisotopic [M+H]+ parent ions, so that deuterium incorporation patterns may be determined directly without the need for isotopic distribution deconvolution. Finally, a higher magnetic field provides for a greatly extending trapping period, for measurement of much slower rates. Angiotensin I, angiotensin II, and [Sar1]-angiotensin II are found to undergo a rapid exchange. Angiotensin II and [Sar1]-angiotensin II exhibit multiple deuterium uptake distributions, corresponding to multiple gas-phase conformations. In contrast, substance P exchanges slowly and LH-RH displays no observable exchange. Comparison of the relative H/D exchange rates for bradykinin and its des-Arg-derivatives supports the hypothesis that bradykinin adopts a folded gas-phase conformation that unfolds upon removal of either terminal arginine residue.
An Analysis of the Association Between Respiratory Symptoms in Subjects with Asthma and Daily Air Pollution in Spokane, Washington

The association between respiratory symptoms and ambient levels of particulate matter (PM) air pollution has been the focus of several panel studies. The majority of studies focused only on PM10, were conducted for relatively short periods, reported peak flow data, and involved children with asthma. The goal of our study was to evaluate the effect of particulate matter of various size fractions (PM10, PM2.5, PM1.0, and PM coarse fraction) on respiratory symptoms in both adults and children with asthma monitored over many months. Daily diary data on respiratory symptoms and medication use were collected. Air pollution data were collected by the local air agency and Washington State University. Data were collected in Spokane, WA, a semiarid city with diverse sources of particulate matter, including motor vehicles, woodstoves, agricultural burning, resuspended road dust, and dust storms. Sixteen adults and nine children living in Spokane participated in the study. The majority of adult subjects participated for over 1 yr and the children were studied for over 8 mo. In the children, we found a strong association between cough and PM10, PM2.5, PM coarse fraction, and PM1.0(p < .05). Sputum production and runny nose were associated with PM10and coarse fraction. However, no association was found between the presence of any respiratory symptom any PM metric in the adult subjects. These positive associations between various metrics of PM and respiratory symptoms in children suggest that children are more sensitive than adults to the effects of increased levels of PM air pollution or that the central site monitor was more representative for children who spend more time outdoors than adults. These findings also suggest that both larger and smaller particles can aggravate asthma symptoms.
Effects of salinity and illumination on photosynthesis and water balance of Spartina alterniflora Loisel.

Plants of the salt marsh grass Spartina alterniflora Loisel were collected from North Carolina and grown under controlled nutrient, temperature, and photoperiod conditions. Plants were grown at two different illumination levels; substrate salinity was varied, and leaf photosynthesis, transpiration, total chlorophyll, leaf xylem pressure, and specific leaf weight were measured. Conditions were controlled so that gaseous and liquid phase resistances to CO2 diffusion could be calculated. Growth at low illumination and high salinity (30 ppt) resulted in a 50% reduction in photosynthesis. The reduction in photosynthesis of plants grown at low illumination was correlated with an increase in gaseous resistance. Photosynthetic rates of plants grown at high salinity and high illumination were reduced only slightly compared to rates of plants grown, in 10 ppt and Hoagland's solution. Both high salinity and high illumination were correlated with increases in specific leaf weight. Chlorophyll data indicate that specific leaf weight differences were the result of increases in leaf thickness. It is therefore hypothesized that photosynthetic response can be strongly influenced by salinity-induced changes in leaf structure. Similarities in photosynthetic rate on an area basis at high, illumination were apparently the result, of increases in leaf thickness at high salinity. Photosynthetic rates were generally quite high, even at salinities close to open ocean water, and it is concluded that salinity rarely limits photosynthesis in S. alterniflora.