cssi/SciSciGPT-SciSciNet huggingface dataset:
962-67 Dobutamine Stress has a Limited Value for Enhancing Flow Heterogeneity in the Presence of a Moderate Stenosis When Used in Conjunction with Tc99m-Sestamibi Imaging

Dobutamine (DOB) is used as an alternative to exercise in conjunction with Tc99m-sestamibi (MB) SPECT perfusion imaging; however, the utility of quantitative DOB MB SPECT to enhance flow heterogeneity is not established, To validate this approach, we injected MB and radiolabeled microspheres in 6 open chest dogs during DOB stress in the presence of a flow limiting LCX stenosis (STEN). The proximal LCX was partially occluded, so as to create a 30 mmHg gradient across the STEN. Radiolabeled microspheres were injected at baseline (BASE), during STEN, and during DOB stress (10 μg/kg/min). MB was injected i.v. at peak DOB. Hearts were excised 20 min after MB injection for postmortem analysis. Hearts were cut into 96 or 192 segments for gamma well counting, for determination of myocardial MB activity and microsphere flow (μFL). The moderate stenosis resulted in impairment of CFR in response to i.c. adenosine (18 μ g) during STEN (pre-STEN: 2.44 ± 0.21; STEN: 1.24 ± 0.05, P l 0.005)as measured by an epicardial flow probe. DOB increased heart rate significantly (Pre-DOB: 112 ± 8 bpm; DOB: 141 ± 8 bpm, p l 0.001), and did not significantly reduce mean aortic pressure (Pre-DOB: 80 ± 5; DOB: 95 ± 7, P = ns). Measured μFL (ml/min/gm) and MB activity for nonischemic (NI) and ischemic (lS) regions are shown below (mean ± SEM): 1S μFL NI μFL IS/NI μFL MB(%NI) BASE 0.88 ± 0.13 0.96 ± 0.18 0.93 ± 0.02 - STEN 0.58 ± 0.14 0.97 ± 0.11 0.59 ± 0.10 - DaB 1.02 ± 0.37 1.87 ± 0.32 * 0.52 ± 0.12 # 0.70 ± 0.06 † * p l 0.05 vs STEN † P l 0.05 vs IS/NI μFL # P = ns vs STEN DOB increased flow in both the NI and IS regions. Myocardial MB activity (%Nl) correlated with flow (MB = 0.69FL + 0.47, r = 0.66, n = 417) when flow was less than 1 ml/min/gm. However, at higher flow ranges (1 to 4.5 ml/min/gm) MB activity did not correlate with flow (MB = 0.04FL + 0.94, r = 0.13, n = 543). This resulted in the underestimation of the relative flow deficit by MB Thus, DOB may have limited value for the enhancement of flow heterogeneity, since (1) DOB does not augment the flow heterogeneity in the presence of a moderate flow limiting STEN (49% reduction CFR), and (2) myocardial MB activity does not correlate with μFL at higher flows induced by DOB.
Associations Between Catastrophizing and Endogenous Pain-Inhibitory Processes: Sex Differences

Abstract Pain catastrophizing is among the most robust predictors of pain outcomes, and a disruption in endogenous pain-inhibitory systems is 1 potential mechanism that may account for increased pain among individuals who report higher pain catastrophizing. Pain catastrophizing may negatively influence diffuse noxious inhibitory controls (DNIC), a measure of endogenous pain inhibition, through complex anatomical circuitry linking cortical responses to pain with processes that modulate pain. The current study examined whether DNIC mediated the relationship between catastrophizing and pain among 35 healthy young adults and examined the moderating effects of sex to determine whether the magnitude or direction of associations differed among men and women. DNIC was assessed using pressure pain thresholds on the forearm before and during a cold pressor task. Using bias-corrected bootstrapped confidence intervals, results showed that diminished DNIC was a significant partial mediator of the relation between greater pain-related catastrophizing and more severe pain ratings. Participant sex moderated these associations; higher catastrophizing predicted lower DNIC for men and women, however, the effect of catastrophizing on pain ratings was partially mediated by DNIC for women only. These findings further support the primary role of pain catastrophizing in modulation of pain outcomes. Perspective These findings support the hypothesis that the heightened pain reported by individuals higher in pain catastrophizing may be related to a disruption in the endogenous modulation of pain, operationalized by assessing DNIC. Whether interventions that reduce pain catastrophizing affect pain outcomes via effects on DNIC is in need of investigation.
Short-circuit current related to active transport of chloride in frog cornea: effects of furosemide and ethacrynic acid

Abstract Active transport of Cl− accounts for 90% of the short-circuit current (s.c.c.) in the isolated frog cornea. 1·10−5 M furosemide produced a 50% reversible inhibition of this s.c.c. 1·10−4 M ethacrynic acid reduced the corneal s.c.c. to 32% of the control. In the isolated frog skin epithelium furosemide had no effect on the s.c. at a concentration of 1·10−4 M and a small stimulation at a concentration of 1·10−3 M. The furosemide inhibitory effects seems to be specific for Cl−, as it also inhibits Cl− transport in the ascending limb of the loop of Henle (Burg, M.B. (1972) Proc. 5th Int. Congr. Nephrol., p. 50, Abstr.).
Accelerator-globulin and prothrombin preparation of accelerator-globulin free plasma.

SummaryThe chemical and/or physical relationship between prothrombin and Ac-globulin apparently is very close as evidenced by the inability to denature, adsorb, precipitate or otherwise inactivate completely, and at times partially, the one, without completely or partially removing or inactivating the other. A method is described whereby oxalated bovine plasma may be rendered free from Acglobulin, but not from prothrombin.
Phylogenetic analysis of glycolytic enzyme expression

Although differences among species in enzyme maximal activity or concentration are often interpreted as adaptive and important for regulating metabolism, these differences may simply reflect phylogenetic divergence. Phylogenetic analysis of the expression of the glycolytic enzymes among 15 taxa of a North American fish genus (Fundulus) indicated that most variation in enzyme concentration is due to evolutionary distance and may be nonadaptive. However, three enzymes' maximal activities covary with environmental temperature and have adaptive value. Additionally, two pairs of enzymes covary, indicating coevolution. Thus, metabolic flux may be modulated by many different enzymes rather than by a single rate-limiting enzyme.
Toral and exponential stabilization for homotopy spherical spaceforms

The Atiyah-Singer equivariant signature formula implies that the products of isometrically inequivalent classical spherical space forms with the circle are not homeomorphic, and in fact the same conclusion holds if the circle is replaced by a torus of arbitrary dimension. These results are important in the study of group actions on manifolds. Algebraic K-theory yields standard classes of counterexamples for topological and smooth analogs of spherical spaceforms. The results of this paper characterize pairs of nonhomeomorphic topological spherical space forms whose products with a given torus of arbitrary dimension are homeomorphic, and the main result is that the known counterexamples are the only ones that exist. In particular, this and basic results in lower algebraicK-theory show that if such products are homeomorphic, then the products are already homeomorphic if one uses a 3-dimensional torus. Sharper results are established for important special cases such as fake lens spaces. The methods are basically surgery-theoretic with some input from homotopy theory. One consequence is the existence of new innite families of manifolds in all dimensions greater than three such that the squares of the manifolds are homeomorphic although the manifolds themselves are not. Analogous results are obtained in the smooth category.
The Biocide Chlorine Dioxide Stimulates Biofilm Formation in Bacillus subtilis by Activation of the Histidine Kinase KinC

Bacillus subtilis forms biofilms in response to signals that remain poorly defined. We report that biofilm formation is stimulated by sublethal doses of chlorine dioxide (ClO2), an extremely effective and fast-acting biocide. ClO2 accelerated biofilm formation in B. subtilis as well as in other bacteria, suggesting that biofilm formation is a widely conserved response to sublethal doses of the agent. Biofilm formation depends on the synthesis of an extracellular matrix that holds the constituent cells together. We show that the transcription of the major operons responsible for the matrix production in B. subtilis, epsA-epsO and yqxM-sipW-tasA, was enhanced by ClO2, in a manner that depended on the membrane-bound kinase KinC. Activation of KinC appeared to be due to the ability of ClO2 to collapse the membrane potential. Importantly, strains unable to make a matrix were hypersensitive to ClO2, indicating that biofilm formation is a defensive response that helps protect cells from the toxic effects of the biocide.
Chorioamnionitis and Neonatal Encephalopathy in Term Infants With Fetal Acidemia: Histopathologic Correlations

The aim of this study was to determine whether the presence or severity of histologic abnormalities of infection/inflammation such as chorioamnionitis, vasculitis, or funisitis confers an additional risk for neonatal encephalopathy in term infants delivered in the presence of severe fetal acidosis. The medical records as well as placental pathology of term infants (n = 51) born with a cord umbilical arterial pH <7.00 were reviewed. Abnormal outcome was predefined as Sarnat stage 2 or 3 neonatal encephalopathy in the first week of life or neonatal death as a consequence of severe brain injury. Consistent with prior data, the presence of severe fetal acidemia, a low 5-minute Apgar score, and need for cardiopulmonary resuscitation were significantly associated with neonatal encephalopathy. However, the presence of histologic chorioamnionitis had a poor predictive value and did not confer additional risk for the subsequent development of neonatal encephalopathy.
Data handling and validation from Wisconsin's remote vehicle emissions sensing studies

The Wisconsin Department of Natural Resources and Department of Transportation (WDOT) are conducting a joint study to determine the effectiveness of applying optical sensing techniques to vehicular emission monitoring. Two field studies using Remote Sensing Technologies, Inc. remote sensing equipment was conducted in 1993 and 1994. This paper describes the data handling and data validation activities of these studies, including identification of data elements. Data handling was performed by the same people who conducted the 180,000 vehicle emissions tests. A contemporary commercial spreadsheet from Borland International, Inc. was used to import the raw data from the remote sensor. The data was reviewed with the spreadsheet then moved into a Borland relational database product. The relational database permitted structured queries against databases of vehicle inspection/maintenance (I/M) data from WDOT, National Insurance Crime Bureau, and EnviroTest. We determined effective cut points for vehicles of different ages which delineated high-polluting vehicles (gross emitters) from vehicles in compliance. The I/M data was also used to intercompare the remote sensing results with traditional testing results. Remote sensing test results were then compared for errors of commission and omission with respect to I/M test. Ultimately, this remote sensing database technique could serve as a means for identifying gross emitters who would be required to visit an I/M facility for an out-of-cycle emissions test.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Response Model Design for a Rhythmic Delta-Platform Domain, Devonian Catskill Complex of New York: ABSTRACT

Investigation of the physical stratigraphy of the Middle and Upper Devonian of southeastern New York has shown that this sequence of the "Catskill Deltaic Complex" might be separated naturally into a set of sedimentary domains. The North Point (lowermost Upper Devonian), one of these domains, is characterized by rhythmic patterns in sediment color, texture, and petrology; sedimentary structures; sediment transport directions; lithologic sequences; and lithosome geometries. The rhythmically recursive sequence of the North Point consists of (in ascending order): (A) polymictic conglomerate, (B) gray conglomeratic subgraywacke, (C) gray subgraywacke, (D) red subgraywacke, (E) red siltstone, (F) red mudrocks, (G) olive mudrocks, (H) gray mudrocks, and (I) sub-protoquartzite. Various physical and statistical models of source, distribution, accumulation, and modification realms of the process-response system of the North Point were simulated on an electronic computer. The algorithm for a model of the process-response system of a rhythmic sequence, obtained by integration of relative aspects of these models, may be approximated by six sub-sets of equations; each sub-set is an attempt to characterize the status of process elements in the development of a response phase. Translated into operational format these phases are: (1) early regressive phase (units A, B,); (2) middle regressive phase (B, C); (3) late regressive phase (D, E); (4) paralic stability phase (E, F); (5) early transgressive phase (G, H); and (6) late transgressive phase (H, I). The general aspect of this model is coarse-grained sediments (A, B, C) passing upward into finer sediments (E, F, G, H), forming a platform sequence which is rhythmically recursive. Homogenization at the strand zone and re-organization on the distal portion of the platform produces an inverted sequence (fines grading upward to coarser units). This model recognizes two components of subsidence, local and regional, as dominant process elements of the accumulation realm. The regional component is decomposed into he effects produced by compaction of the underlying sediment pile and those produced by subsidence of the Devonian sub-basin. The local component results from surface and near-surface compaction of sediment deposited during phases 3, 4, and 5 (units E, F, G, H) of a rhythmic sequence. The algebraic sum of the interaction of these two process elements may have profound effects on the character and mode of the response, producing transgression in one part of the domain, while regression or stability characterizes another part. Within the framework of this model the rhythmic character of the North Point is thought to be the response to the interaction of: (1) source contribution activity; (2) design of transport and dispersal systems; (3) influence of sub-basin and platform dynamics on the character and mode of the accumulation; (4) modification of the accumulation by processes such as compaction, erosion, diagenesis, and structural adjustments. End_of_Article - Last_Page 336------------
The metalloclusters of carbon monoxide dehydrogenase/acetyl-CoA synthase: a story in pictures

Eight Ni proteins are known and three of these, CO dehydrogenase (CODH), acetyl-CoA synthase (ACS), and hydrogenase, are Ni-Fe-S proteins. In the last three years, the long-awaited structures of CODH and ACS have been solved. The bioinorganic community was shocked, as the structures of the active sites of CODH and ACS, the C- and A-cluster, respectively, which each had been predicted to consist of a [Fe4S4] cluster bridged to a single Ni, revealed unexpected compositions and arrangements. Crystal structures of ACS revealed major differences in protein conformation and in A-cluster composition; for example, a [Fe4S4] cluster bridged to a binuclear center in which one of the metal binding sites was occupied by Ni, Cu, or Zn. Recent studies have revealed Ni-Ni to be the active state, unveiled the source of the heterogeneity that had plagued studies of CODH/ACS for decades, and produced a metal-replacement strategy to generate highly active and nearly homogeneous enzyme.
Novel ArF photoresist system using acrylic polymer

A novel resist for 193 nm lithography must be developed to fulfill the demands of future microelectronics fabrication processes. Enhancing 193 nm DUV single layer resist (SRL) materials has received extensive interest in recent years, which exclusively derivatized acrylic polymers due to the problem of absorption at 193 nm. In this work, we investigate acrylic polymers as a 193 nm DUV SLR material. Our acrylic polymer comprises of tertbutyl ester acid labile group and other groups. The resist system using the polymer displays a positive tone image in the presence of photoacid generator such as onium salts. This work also investigates the effects of acid number, acrylic polymer composition, molecular weight of acrylic polymer on 193 nm DUV SLR.
Empirical determination of the mean free path of a nucleon in the nuclear medium

Abstract The mean free path of a nucleon in the nuclear medium extracted from measured neutron-nucleus total cross sections is compared with the values determined from the energy-momentum dispersion relation. The optical potentials used in the dispersion relation are the relativistic global energy-dependent Lorentz scalar and vector potentials of Dirac phenomenology. Excellent agreement between the values extracted from either total neutron-nucleus cross sections or proton-nucleus reaction cross sections and the calculated values is achieved when the optical potentials are evaluated using radial values corresponding to approximately 80% of nuclear matter density.
Discriminative and reinforcing effects of brotizolam in rhesus monkeys.

The reinforcing and discriminative stimulus effects of brotizolam, a benzodiazepine-hypnotic, were evaluated in rhesus monkeys. In one experiment, separate groups of monkeys (N=3/group) were trained to discriminate pentobarbital (10 mg/kg, IG) ord-amphetamine (0.56–1.0 mg/kg, IG) from saline, in a discrete-trials avoidance/escape paradigm. Pentobarbital (5.6–10 mg/kg), diazepam (1.0–1.7 mg/kg), and brotizolam (0.3–1.7 mg/kg) resulted in 100% drug-lever responding in all three pentobarbital-trained monkeys. Ind-amphetamine-trained monkeys brotizolam administration resulted only in saline-lever responding. In another experiment, monkeys were surgically prepared with indwelling intravenous catheters and lever pressing resulted in an injection of 0.1 mg/kg/injection sodium methohexital under a fixed-ratio 10 (FR 10) schedule. Pentobarbital (0.01–0.3 mg/kg/injection) and diazepam (0.003–0.10 mg/kg/injection) maintained responding above saline control levels when substituted for methohexital. Brotizolam (0.001–0.01 mg/kg/injection) resulted in more injections received compared to saline, but fewer injections compared to pentobarbital or diazepam. Thus, results from the present experiment suggest that brotizolam would have pentobarbital-like subjective effects. However, the abuse liability of brotizolam may be lower than that for diazepam.
UV absorber progenitors: Photo-fries rearrangements of sulfonate esters of hydroxyphenylbenzotriazoles†

Benzenesulfonate esters of hydroxyphenylbenzotriazole UV absorbers are described as UV absorber progenitors which can be used in UV-curable coating formulations. During UV exposure, they undergo a photo-Fries rearrangement to form the corresponding o-benzenesulfonyl phenol derivatives. These derivatives are formed in good chemical yield during bulk solution photolyses and are also readily formed in polymer films during exposure to sunlight. The reaction is specific for benzenesulfonate esters; little or no rearrangement takes place with benzyl, naphthyl, or alkylsulfonate esters or with benzoate esters.
Eccentric exercise versus Usual-care with older cancer survivors: The impact on muscle and mobility- an exploratory pilot study

Resistance exercise programs with high compliance are needed to counter impaired muscle and mobility in older cancer survivors. To date outcomes have focused on older prostate cancer survivors, though more heterogeneous groups of older survivors are in-need. The purpose of this exploratory pilot study is to examine whether resistance exercise via negative eccentrically-induced work (RENEW) improves muscle and mobility in a diverse sample of older cancer survivors. A total of 40 individuals (25 female, 15 male) with a mean age of 74 (± 6) years who have survived (8.4 ± 8 years) since their cancer diagnosis (breast, prostate, colorectal and lymphoma) were assigned to a RENEW group or a non-exercise Usual-care group. RENEW was performed for 12 weeks and measures of muscle size, strength, power and mobility were made pre and post training. RENEW induced increases in quadriceps lean tissue average cross sectional area (Pre: 43.2 ± 10.8 cm2; Post: 44.9 ± 10.9 cm2), knee extension peak strength (Pre: 248.3 ± 10.8 N; Post: 275.4 ± 10.9 N), leg extension muscle power (Pre: 198.2 ± 74.7 W; Post 255.5 ± 87.3 W), six minute walk distance (Pre: 417.2 ± 127.1 m; Post 466.9 ± 125.1 m) and a decrease on the time to safely descend stairs (Pre: 6.8 ± 4.5 s; Post 5.4 ± 2.5 s). A significant (P < 0.05) group x time interaction was noted for the muscle size and mobility improvements. This exploration of RENEW in a heterogeneous cohort of older cancer survivors demonstrates increases in muscle size, strength and power along with improved mobility. The efficacy of a high-force, low perceived exertion exercise suggests RENEW may be suited to older individuals who are survivors of cancer. ClinicalTrials.gov Identifier: NCT00335491
An unconditionally positivity preserving scheme for advection–diffusion reaction equations

Abstract Parabolic equations with advection, diffusion and reaction terms are used to model many physical and biological systems. In many applications the unknowns represent quantities that cannot be negative such as concentrations of chemical compounds or population sizes. Widely used schemes such as finite differences may produce negative solutions because of truncation errors and may then become unstable. We propose a new scheme that guarantees the positivity of the solutions for arbitrary step sizes. It works for reaction terms that consist of the sum of a positive function and a negative function. We develop it for one advection–diffusion reaction equation in one spatial dimension with constant velocity and diffusion and state how to generalize it. The method is applicable to both advection and diffusion dominated problems. We give some examples from different applications.
Ab-initio calculations of the elastic and finite-temperature thermodynamic properties of niobium- and magnesium hydrides

Density Functional Theory (DFT) calculations have been used for calculating the elastic and thermodynamic properties of Mg, Nb, and their hydrides. The study is motivated by a previous work that showed constraints arising from Mg/Nb layer interfaces de-stabilized the magnesium hydride and resulted in decomposition temperatures much lower than in the bulk state. The calculated mechanical properties and the difference in the volume expansion of Mg- and Nb-hydrides support the ideas of large, de-stabilizing mechanical stresses arising from significant volume expansion incompatibilities in Mg/Nb multilayers. The stress and corresponding formation of metastable phases result in significant destabilization of MgH2 and provide ultra-low hydrogen desorption temperature in Mg/Nb multilayers.
Automated planning for software architecture evolution

In previous research, we have developed a theoretical framework to help software architects make better decisions when planning software evolution. Our approach is based on representation and analysis of candidate evolution paths--sequences of transitional architectures leading from the current system to a desired target architecture. One problem with this kind of approach is that it imposes a heavy burden on the software architect, who must explicitly define and model these candidate paths. In this paper, we show how automated planning techniques can be used to support automatic generation of evolution paths, relieving this burden on the architect. We illustrate our approach by applying it to a data migration scenario, showing how this architecture evolution problem can be translated into a planning problem and solved using existing automated planning tools.
Kinetics of HPV11 DNA replication after infection of keratinocytes with virions

Human papillomavirus type 11 (HPV11) normally infects keratinocytes of stratified epithelia and replicates as an episome. To untangle early events in the development of a papilloma, we have infected human keratinocytes with human papillomavirus type 11 virions and monitored replication using density labeling with bromodeoxyuridine and subsequent density centrifugation. We show that only a portion of the virus reaching the nucleus undergoes replication and that continued replication occurs without recruitment from the nonreplicating pool of virus suggesting that HPV11 replication remains confined to a small number of cells. Increasing inoculum size leads to more viral DNA reaching the nucleus but not a corresponding increase in viral replication. Subsequent papilloma development must, therefore, occur within a small subset of cells.
Computer-aided selection of efficient identification features and calculation of group descriptors as exemplified by data onCapnocytophaga species

Large volumes of data must be analyzed for numerical descriptions of taxa and subsequent construction of identification schema. To aid in these data-reduction tasks, we have devised (and made available) three computer programs, which (i) order strains on the basis of cluster analyses (or some other grouping procedure), (ii) determine statistics useful in describing groups (feature frequencies, hypothetical modal organisms, actual modal organisms, feature uniqueness, and ability of each feature to partition the groups), and (iii) determine if there is a redundancy between features which otherwise would be useful in separating the groups. The programs form logical step-by-step aids to microbiologists devising matrices for the identification of microbial species. The use of the programs is illustrated by reducing 175 features to a six-feature matrix for identifying four groups ofCapnocytophaga.
Mesalamine derivatives in the treatment of Crohn's disease

The role of the aminosalicylates for induction therapy of mild moderate ulcerative colitis and as maintenance treatment has been substantiated by a large series of controlled clinical trials and confirmatory meta-analyses. Both sulfasalazine and newer derivatives are effective in preventing relapses. It remains to be determined whether certain high-risk groups of patients may benefit from higher doses of mesalamine induction or maintenance therapy. Mesalamine derivatives are also of benefit in the treatment of Crohn's disease. Sulfasalazine is likely not effective in the maintenance of Crohn's disease, although other mesalamine formulations continue to show some prophylactic activity after mesalamine induced remissions and for patients with disease of the ileum who have undergone surgical resection.
Characterizations of HgTe nanocrystals induced by controlled precipitation in PbTe-4HgTe semiconductor alloys

This paper reports the observation of HgTe precipitate formation and its subsequent evolution in a PbTe semiconductor matrix containing 4 mol. % HgTe (PbTe-4HgTe) produced by a controlled precipitation process. The controlled precipitation process is being developed as a new way to produce a large number of quality semiconductor nanocrystals more simply than the conventional methods. Characterization of the HgTe precipitates resulting from application of controlled precipitation to the PbTe-4HgTe alloy system provides evidence that this method is effective in generating nanocrystals. Transmission electron microscopy of the processed alloys reveals that HgTe precipitates are extremely small in size, maintain a coherent interface, and experience a unique shape evolution with aging.
Spin-orbit coupling in aromatic hydrocarbons. The radiative triplet lifetime of naphthalene

A radiative triplet lifetime of 15 sec is calculated for naphthalene on the basis of σπ-interaction, involving singlet and triplet πσ* and σπ* states.
Floating-point processors join forces in parallel processing architectures

The hardware architecture and software capabilities of the TMS320C40 floating-point digital signal processor are described. The C40 operates at 275 million operations per second (MOPS) and transfers data at a rate of 320 Mbytes/s with a 40-ns cycle time. A key architectural feature of the C40 for parallel computing is the six parallel bidirectional communication ports that permit direct connection and communication between processors in a parallel system. Examples illustrating the use of the C40 in a parallel processing environment are discussed. >
The effects of load ratio on environmentally assisted fatigue crack growth

Abstract A modification to the model of Weir et al. for surface reaction and transport controlled fatigue crack growth has been developed to explicitly account for the effect of load ratio on environmentally assisted fatigue crack growth. Load ratio was found to affect principally gas transport to the crack tip, and therefore affected only transport controlled crack growth response. Experimental verification of the modified model was made by studying the room temperature fatigue crack growth responses at different load ratios for a 2219-T851 aluminum alloy exposed to water vapor. The results show that the effects of load ratio can be attributed to two different sources—one relating to its effect on local deformation at the crack tip and is reflected through the mechanical component, (d a /d N )0 and the other on its role in modifying environmental effect and is manifested through the corrosion fatigue component, (da/dN) cf Furthermore, the results show that the saturation value of corrosion fatigue component, (da/dN) cf,s , is essentially independent of R , and that the exposure needed to produce “saturation response” ( P 0 /2f) s , as a function of load ratio can be predicted from the modified model. The modified model, therefore, allows one to predict the corrosion fatigue crack growth response for any load ratio on the basis of measurements made at a single load ratio, provided that the values of ( da/dN ), are known.
Knowledge based dimensionality reduction for technical text mining

In this paper we propose a novel technique for dimensionality reduction using freely available online knowledge bases. The complexity of our method is linearly proportional to the size of the full feature set, making it applicable efficiently to huge and complex datasets. We demonstrate this approach by investigating its effectiveness on patent data, the largest free technical text. We report empirical results on classification of the CLEF-IP 2010 dataset using bigram features supported by mentions in Wikipedia, Wiktionary, and GoogleBooks knowledge bases. We achieve a 13-fold reduction in number of bigrams features and a 1.7% increase in classification accuracy over the unigrams baseline. These results give concrete evidence that significant accuracy improvements and massive reduction in dimensionality could be achieved using our approach, hence help alleviating the tradeoff between task complexity and accuracy.
The effects of acids, alkalies, and chelating agents on dentine permeability.

Abstract The ability of eight different solutions to increase or decrease dentine permeability was evaluated in extracted human two-rooted maxillary premolars. Thirteen teeth were used in each group, making a total of 104 teeth. The Dentine Permeability Index18 was used to calculate the depth of penetration of a 2 per cent methylene blue dye into the dentinal tubules. For statistical analysis and subsequent comparisons, only ten teeth were used from each group (a total of eighty teeth). It was found that R-C Prep alternating with 5 per cent sodium hypochlorite increased dentine permeability in the apical and middle thirds of the root more than any other solution. Concentrated sulfuric acid almost eliminated dentine permeability.
Thermal Expansion Of GaN And Ain

The temperature dependence of the thermal expansion and the bulk modulus are critical for predicting the residual stress distribution in epitaxial films and provides information relevant for interatomic potentials and equations of state. The thermal expansions of aluminum nitride (AIN) and gallium nitride (GaN) are calculated with two models that employ the limited elastic and lattice parameter data. These semiempirical models allow prediction of the thermal expansions to higher temperatures. Calculated results are compared with experimental data.
Seasonal pattern of nitrogen mineralization and soil moisture beneath Faidherbia albida (syn Acacia albida ) in central malawi

On fertile alluvial soils on the lakeshore plain of Malawi, maize (Zea mays L.) yields beneath canopies of large Faidherbia albida (synAcacia albida) trees greatly exceed those found beyound tree canopies, yet there is little difference in soil nutrients or organic matter. To investigate the possibility that soil nutrient dynamics contribute to increased maize yields, this study focused on the impact of Faidherbia albida on nitrogen mineralization and soil moisture from the time of crop planting until harvest. Both large and small trees were studied to consider whether tree effects change as trees mature.
Theory of optical Λ transitions in the N 15 -V − center in diamond: Role of the hyperfine interaction

We present a thorough derivation of the excited-state energy levels of the negatively charged $^{15}\text{N}{\text{-V}}^{\ensuremath{-}}$ center in diamond for the strong applied electric-field case. We show that in the $^{15}\text{N}{\text{-V}}^{\ensuremath{-}}$ center a spin nonconserving two-photon $\ensuremath{\Lambda}$ transition exists that is mediated by the hyperfine interaction, which provides the possibility to write quantum information. Using second-order perturbation theory we obtain a $\ensuremath{\Lambda}$ transition rate of the order of 10 MHz at room temperature, which allows for approximately ${10}^{4}$ quantum logic operations within the spin coherence time ${\ensuremath{\tau}}_{d}(T=300\text{ }\text{K})\ensuremath{\approx}1\text{ }\text{ms}$ of the $^{15}\text{N}{\text{-V}}^{\ensuremath{-}}$ center.
An electric current tomograph

A description is given of an instrument designed to acquire data for the construction of images of internal body structures based on measurements of electrical impedance made from a set of electrodes applied around the periphery of the body. The instrument applies currents at 15 kHz in any desired pattern to 32 electrodes and measures the resulting voltage at each electrode. The construction of a test phantom is also described and the results of initial studies showing the distinguishability of targets of differing sizes and conductivities placed in the phantom are reported. The system is able to distinguish the presence of 9-mm-diameter insulators or conductors placed in the center of a 30-cm-diameter circular tank of salt water. This system is capable of implementing an adaptive process of produce the best currents to distinguish the unknown conductivity from a homogeneous conductivity. >
Far-Field RF Powering of Implantable Devices: Safety Considerations

Far-field RF powering is an attractive solution to the challenge of remotely powering devices implanted in living tissue. The purpose of this study is to characterize the peak obtainable power levels in a wireless myoelectric sensor implanted in a patient while maintaining safe local temperature and RF powering conditions. This can serve as a guide for the design of onboard electronics in related medical implants and provide motivation for more efficient power management strategies for implantable integrated circuits. Safe powering conditions and peak received power levels are established using a simplified theoretical analysis and Federal Communications Commission-established limits for radiating antennas. These conditions are subsequently affirmed and improved upon using the finite-element method and temperature modeling in bovine muscle.
Ocular Hypotensive Action of Labetalol

Labetalol has a unique and profound effect on the IOP of rabbits, in contrast to pure beta-adrenergic blockers which have little or no effect in this animal. Its action cannot be satisfactorily explained by simple alpha and beta-adrenergic blocking activity. In the concentrations used, it failed to block the action of a beta-adrenergic agonist (isoproterenol), the action of an alpha-adrenegic agonist (norepinephrine), and its own hypotensive action was neither blocked nor potentiated by the alpha-adrenergic blocker phenoxybenzamine. However, the beta blocker, timolol, did reduce the action of labetalol. These observations and the reduced response to labetalol after cervical sympathectomy, suggest that labetalol's ocular hypotensive effect may occur through some mechanism other than alpha or beta blockade.
Case problems for problem-based pedagogical approaches: A comparative analysis

A comparative analysis of 51 case problems used in five problem-based pedagogical models was conducted to examine whether there are differences in their characteristics and the implications of such differences on the selection and generation of ill-structured case problems. The five pedagogical models were: situated learning, goal-based scenario, learning-by-design, problem-based learning and cognitive flexibility hypertext. The analysis revealed that while all case problems were authentic and multi-disciplinary, they varied across six themes for the pedagogical models examined: problem complexity, nature of problem topic, problem task, problem product, problem solving activity, and type of effort. The analysis also revealed that different kinds of case problems (e.g., dilemmas, design problems, case-analysis problems) are appropriate for different problem-based pedagogical models. These findings and their educational implications are described.
Analysis of vibrational‐translational energy transfer using the direct simulation Monte Carlo method

A new model is proposed for energy transfer between the vibrational and translational modes for use in the direct simulation Monte Carlo method (DSMC). The model modifies the Landau–Teller theory for a harmonic oscillator and the rate of transition is related to an experimental correlation for the vibrational relaxation time. Assessment of the model is made with respect to three different computations: relaxation in a heat bath, a one‐dimensional shock wave, and hypersonic flow over a two‐dimensional wedge. These studies verify that the model achieves detailed balance, and excellent agreement with experimental data is obtained in the shock wave calculation. The wedge flow computation reveals that the usual phenomenological method for simulating vibrational nonequilibrium in the DSMC technique predicts much higher vibrational temperatures in the wake region. Additionally, the numerical performance of the new model is equal to that of the phenomenological scheme.
Organizational (soft) GIS interoperability: lessons from the U.S.

Abstract Despite the numerous difficulties, many agencies and institutions in the United States and worldwide practice sharing of geographic information systems (GIS) and data, amounting to local, regional, national and international spatial data infrastructures. While the evidence on coordinated GIS development and spatial data sharing accumulates, there have been a few systematic evaluations of mechanisms and factors that facilitate or obstruct interorganizational GIS efforts. Moreover, the issue of “interoperability” has been addressed primarily in technical terms with its “soft” or organizational side mostly neglected. This paper presents results from several recent studies in the U.S. context. It explores the nature and effectiveness of interorganizational interaction, coordination and implementation processes, and assesses the benefits from achieving organizational interoperability.
Release of cholecystokinin from rat cerebral cortex in vivo: role of GABA and glutamate receptor systems.

Using cortical cups in chloralose-urethanized rats, the in vivo release of cholecystokinin-like immunoreactivity (CCK-LI) from cerebral cortex was examined. Resting levels of cholecystokinin-like immunoreactivity ranged from 20 to 30 pg/20 min sample. The addition of potassium (40 mM) in excess, resulted in a highly significant elevation in the levels of CCK-LI in the cortical superfusate. Deletion of calcium and the substitution of cobalt (10 mM), resulted in a significant reduction in both resting release and the release otherwise evoked by the addition of potassium. Focal electrical stimulation of the cortex (20 Hz), resulted in a significant (1.9 ± 0.2-fold, n = 8) increase in the levels of CCK-LI. The addition of glutamate (10−6−10−4 M) of kainic acid (10−8−10−6 M), also resulted in significant elevations in the levels of CCK-LI. The co-administration of a putative glutamate receptor antagonist, kynurenic acid (10−4 M) resulted in a significant reduction in the levels of release otherwise evoked by the addition of glutamate, but not electrical stimulation. The addition of GABA (10−5−10−3 M) resulted in a dose-dependent decrease in the resting release of CCK-LI, and the release evoked by glutamate. Picrotoxin (10−6−10−4 M), resulted in a highly significant increase in the levels of CCK-LI in the cortical effluent. These results are consistent with a tonic GABAergic inhibition of CCK-releasing neurons. The treatment of the animal with diazepam (30 mg/kg, i.p.) also resulted in a significant reduction in resting release and the release otherwise evoked by focal cortical stimulation.
Failure of Compensatory (Catch-up) Growth in the Rat

Extract: Growth retardation was produced in rats of the Long-Evans strain, 37–41 days of age, by withholding food, by daily injection of 5 mg cortisone subcutaneously, or by feeding a diet containing 0.1 % propylthiouracil (PTU). The duration of fasts were 24, 48, and 72 hr in different experiments. Duration of cortisone or PTU treatment was adjusted to produce maximum differences in body weight between control and experimental groups that were equivalent to the difference produced in the corresponding fast periods. Serial measurements of body weight and tail length were carried out for 60–80 days from the start of the experimental treatments. In the fasting experiments, after feeding was resumed the body weight showed a prompt acceleration and nearly complete catch-up during the course of the observations. Tail length growth decelerated during fasting and then accelerated on refeeding. This resulted in complete catch-up. After cortisone treatment there was no catch-up in body weight or tail length growth. After PTU there was a slight tendency to catch-up in body weight and tail length. The latter appeared to show a pattern of late catch-up. Growth velocity curves for these experiments showed transient changes in growth rates which eventually stabilized by 75 days of age, at about the time the animals became sexually mature. The results suggest that in the rat cortisone treatment in the postweaning period permanently damages growth mechanisms and prevents growth recovery in certain circumstances. Hypothyroidism also results in impairment in catch-up growth, but there appears to be some tendency for a delayed catch-up, especially in skeletal growth. Speculation: Failure of full catch-up by one part of an organism after transient growth arrest may be the result of either (1) damage to growth mechanisms of the part or (2) restriction of growth of the part by a control operating to maintain normal proportions in the organism.
Atomic absorption analyses of 18 elements from a single decomposition of aluminosilicate

Abstract The atomic absorption determination of 18 elements in aluminosilicate minerals and marine sediments is accomplished after a single decomposition method using hydrofluoric acid and aqua regia. The digested sample is combined with boric acid to give a 100 ml solution from which all 18 elements including Si, Ti, V, and Al can be determined directly by means of atomic absorption spectroscopy. Inter-element interferences and ionization effects are fully compensated by using combined standards having a matrix similar to that of the samples. Precision and accuracy for most determinations are comparable to the other more complex analytical techniques while the speed of analyses is considerably faster than existing methods.
Reactions of 2 -dichloromethylbenzimidazole with certain primary amines

An investigation of the reactions of 2,2-dichloromethylbenzimidazole with primary amines has led to the synthesis of 2(N-t-butylformimidoyl)benzimidazole, 2-N-(2-phenylethyl)formimdoylbenzimidazole, and 1-(ethoxyearbonylmethyl)-2-(N-t-butylformimidoyl)benzimidazole. Under mild alkali conditions, 2,2-dichloromethylbenzimidazole was rapidly converted into a dimer, namely, 6H,13H-pyrazino[1,2-a:4,5-a']bisbenzimidazole-6,13-diol.
Pandemic influenza: studying the lessons of history

Next year will mark the 90th anniversary of the great influenza pandemic of 1918, an event widely considered to be one of the greatest natural disasters in human history. Historians estimate that ≥50 million people died worldwide, including >450,000 documented deaths in the United States alone (1). Since then, the 20th century witnessed two more influenza pandemics, although fortunately none comparable in ferocity to the 1918 pandemic (2). Pandemics—epidemics so large that virtually the entire world is affected—have occurred several times in each of the last several centuries. Most virologists therefore believe that it is inevitable that we will experience at least one pandemic in this century, and very likely more. However, if a pandemic were to strike in the near future, it is likely that vaccine would not be available for at least 4–6 months (3). Antivirals, if effective against the pandemic strain, would probably also be in short supply. Few of these measures can be applied at pandemic scale, in which half the population of the world would likely be infected over the course of a year or more. We would be left with other measures, now termed “nonpharmaceutical interventions,” to stave off the worst effects of a pandemic until a vaccine could be produced and widely administered (4, 5). Because many of these interventions, such as closing schools or shutting down mass transit, could be very disruptive to society, it is important to use effective measures in a rational way. But which measures are most effective, and how should they be applied? Do any nonpharmaceutical interventions actually help? Until now, there has been very little systematic examination of these questions. However, different U.S. cities showed marked differences in influenza attack rates and mortality in 1918. Some cities, St. Louis for example, appeared to have weathered the …
Angiotensin II AT2 receptor regulates ureteric bud morphogenesis.

ANG II AT2 receptor (AT2R)-deficient mice exhibit abnormal ureteric bud (UB) budding, increased incidence of double ureters, and vesicoureteral reflux. However, the role of the AT2R during UB morph...
Self-assembled peptides exposing epitopes recognizable by human lymphoma cells.

A bifunctional N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer containing nitrilotriacetic acid (NTA) and benzophenone (BP) groups was synthesized by free-radical copolymerization of HPMA, 2-methacrylamidobutyl nitrilotriacetic acid (MABNTA), and 4-methacrylamido benzophenone (MABP) using 2,2‘-azobisisobutyronitrile (AIBN) as initiator. A His-tagged coiled coil stem loop peptide containing a tridecapeptide (TDP) epitope (GFLGEDPGFFNVE) in the loop region (CCSL-TDP) was designed and synthesized genetically by expressing an artificial gene in Escherichia coli BL21 (DE3). The peptide was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), size-exclusion chromatography (SEC), and circular dichroism (CD) spectroscopy. Surfaces containing self-assembled CCSL-TDP peptide were prepared by first covalently grafting poly(HPMA-co-MABNTA-co-MABP) onto polystyrene (PS) surface by UV irradiation, then charging the surface with nickel through NTA groups, and f...