cssi/SciSciGPT-SciSciNet huggingface dataset:
May the force be with you

This paper is a critical assessment of argumentum ad baculum, or appeal to force. Its principal contention is that, contrary to common opinion, there is no general fallacy of ad baculum. Most real-life ad baculums are, in fact, fairly strong. A basic logical form for reconstructed ad baculums is proposed, and a number of heterodoxical conclusions are also advanced and argued for. They include that ad baculum is not necessarily a prudential argument, that ad baculum need not involve force, violence, or threats, and that one can argue ad baculum to oneself. The starting point of the paper, however, is a critical evaluation of three ad baculums from the exercise sets of Irving Copi's well-known Introduction to Logic.
Synergism of a natural plant product, oleanolic acid with calcineurin inhibitor in prolonging islet allograft survival.

Abstract Background Oleanolic acid (OA) is a natural plant-derived triterpenoid with potent anti-inflammatory properties. Since inflammatory cytokines released following islet transplantation hinders engraftment and long-term function, we determined the synergistic ability of OA to with Cyclosporine-A (CSA), a calcineurin inhibitor in improving islet allograft's function and survival. Methods C57BL/6 mice were rendered diabetic using streptozotocin (200 mg/kg). BALB/c islets were transplanted under the kidney capsule alone (control) or along with administration of OA alone, CSA alone or a combination of both OA and CSA (OA + CSA). T-cell infiltration was analyzed by immunohistochemistry; cytokine concentration was analyzed by Luminex; T-cell cytokine phenotype was analyzed by ELISpot; and alloimmune response was analyzed by flow cytometry. Results OA + CSA markedly prolonged islet allograft survival compared to controls (37 ± 5 days vs. 8 ± 3 days). A significant decrease of CD4 + (34 ± 9 vs. 154 ± 42 cells/hpf) and CD8 + T-cellular (46 ± 22 vs. 224 ± 51 cells/hpf, p Conclusions OA and CSA exert synergistic effect towards enhancing islet allograft survival and function. This synergistic effect resulted in markedly reduced graft infiltrating cells with attenuation of inflammatory cytokine milieu leading to impairment of both cellular and humoral alloimmune responses. Therefore, novel therapeutic approaches involving combination of OA with calcineurin-inhibitor based immunosuppressant CSA will produce potential beneficial outcomes in clinical islet transplantation.
Temperature of conducting ribbon magnet coils

THIS PAPER applies the theory of heat flow to finding the steady-state temperature in excess of the surrounding iron. The ribbon coils may be either copper or aluminum, and may be either two or four in number. The magnets considered are large magnets of circular cylindrical shape such as lifting magnets.
Expression of plasminogen activator inhibitor type 2 in normal and psoriatic epidermis

The plasminogen activator (PA) proteolytic cascade has been implicated in the regulation of cell activities, including proliferation and differentiation, both of which occur continuously in normal human epidermis and are aberrant in psoriatic epidermis. To elucidate further the mechanisms by which PA is regulated in epidermis, we evaluated the levels of PA inhibitors type 1 (PAI-1) and type 2 (PAI-2) in normal and psoriatic epidermis. PAI-2, but not PAI-1, was detectable by mRNA, antigen, and activity assays, indicating that PAI-2 is the predominant epidermal PA inhibitor. In situ hybridization revealed that PAI-2 mRNA occurred throughout normal epidermis, although the signal was most intense in the granular layers. Similarly, PAI-2 antigen was most prominent in the granular layers; its distribution in these differential layers was along the cell periphery. Diffuse, fainter staining for PAI-2 was also detected in the basal cells and in some spinous layers of normal epidermis. Extracts of normal epidermis contained PA inhibitory activity identified as PAI-2 by immunoprecipitation with specific antibody. In psoriatic epidermis, PAI-2 mRNA and antigen were most prominent in the more superficial layers beneath the cornified cells. As with normal epidermis, PAI-2 assumed a pericellular distribution in the psoriatic cells. These data demonstrate that PAI-2 is constitutively expressed in vivo by keratinocytes in human epidermis and indicate that this protein is the predominant inhibitor of PA activity in normal and psoriatic human epidermis.
PSEUDOSPIN SYMMETRY AND THE NUCLEON–NUCLEON INTERACTION

Pseudospin symmetry is an approximate relativistic symmetry of the nucleus as demonstrated by experimental data. This symmetry follows from the fact that the vector and scalar potentials of nucleons moving in a relativistic mean field are approximately equal in magnitude and opposite in sign. QCD sum rules in nuclear matter support this conclusion. Such an observation suggests a fundamental reason for pseudospin symmetry. We review the status of pseudospin symmetry conservation in the nucleon–nucleon interaction.
Control of acetylcholinesterase gene expression during myogenesis

Acetylcholinesterase (AChE) and the nicotinic acetylcholine receptor show enhanced expression upon differentiation of C2-C12 myoblasts into myotubes. Northern blots and RNAase protection show substantial increases in the mRNAs encoding both proteins. In contrast to transcriptional control of gene expression of acetylcholine receptor subunits during differentiation, Ache mRNA levels increase through stabilization of the transcript. The transcriptional rate remains unchanged during Ache mRNA accumulation, whereas transcription rate increase for the receptor subunits. Inhibition of protein synthesis produces a dramatic superinduction of Ache mRNA in undifferentiated cells without affecting transcription rates, suggesting the presence of labile proteins that uniquely destabilize the mRNA. Hence, Ache mRNA in myoblasts shows rapid turnover, and upon differentiation, its level is increased by slowing the rate of mRNA degradation.
The effect of temperature on the

The tensile stress-strain behavior and failure mechanisms of Ti-24Al-11Nb and a SiC/ Ti-24Al-11Nb composite with continuous SCS-6 fibers oriented parallel to the loading direction have been examined over a range of temperatures from 23 °C to 815°C in air. Failure in Ti- 24Al-11Nb occurred at strains of approximately 4 pct soon after crack initiation at low tem- peratures. Ductility increased with temperature up to a maximum of 20 pct elongation at 600 °C, as surface-initiated cracks did not propagate readily at intermediate temperatures. At higher temperatures, the onset of grain boundary and interfacial void nucleation limited ductility. Com- posite failure appeared to be controlled by fiber fracture at all temperatures; for practical en- gineering purposes, composite failure occurred at 0.8 pct strain at all temperatures. At temperatures of 425 °C and less, fiber fractures occurred at intervals along the lengths of the fibers and appeared to be cumulative, while at temperatures of 650 °C and greater, fiber fractures were only observed locally to the fracture surfaces. The decreased radial residual stresses, interfacial strengths, and matrix properties at 650 °C and 815 °C allowed the composite to unload at 0.8 pct strain, due to fiber fractures, followed by a reloading in which fibers pulled out and the matrix failed, resulting in composite failure. The decreasing residual stresses with increasing temper- ature determined from an elastic-plastic concentric cylinder model were shown to affect the stress-strain response of the composite and were consistent with the measured decreasing inter- facial shear stresses, the increased fiber pullout with temperature, and the circumferential de- bonding observed around the fibers at higher temperatures.
Five-brane instantons and R**2 couplings in N=4 string theory

We compute the gravitational coupling F{sub 1} for type IIA string theory on K3{times}T{sup 2} and use string-string duality to deduce the corresponding term for heterotic string on T{sup 6}. The latter is an infinite sum of gravitational instanton effects which we associate with the effects of Euclidean five-branes wrapped on T{sup 6}. These five-branes are the neutral five-branes or zero-size instantons of heterotic string theory. {copyright} {ital 1998} {ital The American Physical Society}
Stratified Sample Surveys with Multiplicity

Abstract Sampling variances are compared for the conventional and for two classes of multiplicity estimators based on stratified sample surveys. The conventional estimator uniquely links every individual to a single enumeration source—its index source. The multiplicity estimators link every individual to its index source, and possibly to other sources as well. One multiplicity estimator permits an individual to be linked to sources in one stratum only; the other multiplicity estimator permits an individual to be linked to any sources. None of the three estimators is necessarily more reliable than the others.
Application of lectin cytochemistry to the study of human neuromuscular disease.

This is a review of the application of cell surface cytochemistry to the study of human neuromuscular disease. The advantages and limitations of the use of lectins coupled to peroxidase are discussed, and the application of this technique is illustrated by a study of the surface of muscle cells in Duchenne muscular dystrophy and polymyositis.
Electrostatic and electrokinetic effects on hindered diffusion in pores

When a macromolecule or colloidal particle is in a pore of comparable size, there will be an increase in its drag coefficient due to hydrodynamic interactions with the pore wall, which reduces the particle diffusivity. For charged particles, there can be additional drag due to the distortion of the electrical double layer caused by particle motion. This electrokinetic retardation was evaluated for a sphere in a cylindrical tube, the surfaces being of like charge and constant charge density. This was done using finite element solutions of the equations of motion, Poisson's equation, and conservation equations for small ions in the electrolyte. A perturbation scheme was employed involving both the particle Peclet number and the particle or pore surface charge density. The results indicate that electrokinetic retardation might noticeably decrease the intrapore diffusivity of a charged macromolecule, relative to that for an uncharged molecule of the same size. The increase in drag (or reduction in mobility) due to electrical charge was found to be much greater for confined particles than for ones in bulk solution, especially for large Debye lengths. However, the electrostatic decrease in the equilibrium partition coefficient was shown to be a more important determinant of the overall diffusional permeability. In other words, the effects of charge on the partition coefficient of a macromolecule outweighed their effects on the intrapore diffusivity.
Electrophysiologic effects, clinical efficacy and safety of intravenous and oral nadolol in refractory supraventricular tachyarrhythmias

The electrocardiographic and electrophysiologic effects, clinical efficacy and safety of intravenous and oral nadolol therapy were examined in 34 patients with recurrent supraventricular tachyarrhythmias (SVT) undergoing electrophysiologic evaluation. Programmed electrical stimulation was performed in the control (drug-free) state, after infusion of intravenous nadolol (mean dose 0.09 +/- 0.03 mg/kg) and after chronic oral nadolol therapy in patients who responded to intravenous nadolol (mean dose 83 +/- 12 mg for 5 days). Intravenous nadolol administration prolonged mean sinus cycle length (p = 0.009), mean PR interval (p = 0.001) and mean AH interval (p = 0.001), with no significant electrophysiologic effects in the atrium, ventricle or accessory bypass tracts. Oral nadolol had similar electrocardiographic and electrophysiologic effects, but of lesser magnitude. Intravenous nadolol resulted in complete suppression of induced SVT in 78% of patients with sinus and atrioventricular nodal reentrant tachycardia and 11% of patients with atrioventricular (AV) reentrant tachycardia (p less than 0.001). Partial responses were frequent in intraatrial or AV reentrant tachycardia (37%). Oral nadolol suppressed induction of SVT in patients who responded to intravenous nadolol. Adverse reactions to intravenous and oral nadolol were infrequent--6% and 8%, respectively--and usually did not require drug withdrawal. Intravenous nadolol is highly effective in sinus and AV nodal reentrant tachycardia, and a successful electrophysiologic response to it predicts efficacy of long-term oral nadolol therapy. It has limited efficacy alone in AV reentrant tachycardia and should be considered in combination with other antiarrhythmic therapy in this type of SVT.
Hydraulic design and optimization of a modular pump-turbine runner

A novel modular pumped-storage scheme is investigated that uses elevated water storage towers and cement pools as the upper and lower reservoirs. The scheme serves a second purpose as part of the wastewater treatment process, providing multiple benefits besides energy storage. A small pumped-storage scheme has been shown to be a competitive energy storage solution for micro renewable energy grids; however, pumped-storage schemes have not been implemented on scales smaller than megawatts. Off-the-shelf runner designs are not available for modular pumped-storage schemes, so a custom runner design is sought. A preliminary hydraulic design for a pump-turbine runner is examined and optimized for increased pumping hydraulic efficiency using a response surface optimization methodology. The hydraulic pumping efficiency was found to have improved by 1.06% at the best efficiency point, while turbine hydraulic efficiency decreased by 0.70% at the turbine best efficiency point. The round-trip efficiency for the system was estimated to be about 78%, which is comparable to larger pumped-storage schemes currently in operation.
Low-temperature photon echo study of 2-MTHF glass under high pressure

A high-pressure photon echo study of the low-temperature dynamics of rhodamine 640 in a 2-methyltetrahydrofuran (2-MTHF) molecular glass is reported. High pressure is found to decrease the homogeneous dephasing rate comparably to the volume compression ratio. The pressured-induced line narrowing is also qualitatively similar to high-pressure hole burning results reported for a 2-MTHF glass doped with bacteriochlorophyll a. The results are consistent with a pressure-induced decrease in the number of tunneling two-level systems (TLSs) that may be associated with collapsible void space in the molecular glass. Comparable high-pressure photon echo studies of organic polymer glasses over the same low-temperature range do not show line narrowing at high pressure, suggesting an intrinsic difference in the nature of TLSs for molecular versus polymer glasses.
Vascular Access Calcification and Arteriovenous Fistula Maturation

The vascular access serves as the "lifeline" for the hemodialysis patient, but in recent years has become the "Achilles Heel" of the hemodialysis procedure. The vascular health of the vessels used to create arteriovenous accesses is paramount to vascular access maturation and successful outcomes. Vascular calcification is widely present in the vessels of chronic kidney disease (CKD) and end stage renal disease (ESRD) patients, and may also potentially impact the vascular access remodeling process. Few studies have been published to date evaluating vascular calcification as it relates to vascular access outcomes. However, an improved understanding of how vascular calcification plays a pathophysiological role in hemodialysis vascular access dysfunction may improve therapies to treat arteriovenous fistula (AVF) non-maturation and the health of the vessels prior to vascular access creation.
Hagar and Ishmael: A Commentary:

This essay offers a commentary on the short story of Hagar and Ishmael’s expulsion at the hands of Abraham (Gen 21:14–20). The commentary lays a claim on traditional interpretation but is not itsel...
Effect of statin drugs on thoracic aortic aneurysms.

Pharmacologic interventions for thoracic aneurysms remain poorly characterized. The results of a pilot study by our group suggested improved outcomes among patients with thoracic aortic aneurysm who were taking statins. In the present study, we undertook a comprehensive analysis of a larger cohort of patients from the Database of the Aortic Institute at Yale-New Haven Hospital. A total of 1,560 patients met the inclusion criteria. The adverse events (i.e., death, dissection, or rupture) and surgery rates for patients with (n = 369, 24%) and without (n = 1,191, 76%) statin therapy were compared. We evaluated 3 anatomic components of the aorta: root, ascending and arch, and descending and thoracoabdominal aortic aneurysms. A smaller proportion of the statin group had adverse events: overall, 7% versus 15%; ascending and arch, 6% versus 15%; and descending and thoracoabdominal aortic aneurysms, 8% versus 20%. Also, a smaller proportion of statin patients required surgery: overall, 48% versus 60%; ascending and arch, 51% versus 62%; and descending and thoracoabdominal aortic aneurysms, 36% versus 59% (p
Reversal of neuronal and cognitive consequences of amphetamine sensitization following chronic treatment with a D1 antagonist.

Abstract Neuroplasticity is a key factor in restoration of brain function following neuropathology associated with disease or drug exposure. Here we examined the potential for chronic treatment with the selective D1 receptor antagonist SCH39166 to reverse the profound and enduring cognitive impairment associated with amphetamine (AMPH) sensitization in the nonhuman primate and to stimulate re-growth of atrophied pyramidal dendrites in the dorsolateral prefrontal cortex of these animals. Four rhesus monkeys with sustained cognitive impairment (> 1 year following AMPH sensitization) were treated for up to 8 months with SCH39166. Cognitive testing was performed before, during, and for up to 1½ year following treatment. Significant improvement in working memory performance was observed only after cessation of the D1 antagonist treatment but then was sustained for the duration of the post-treatment testing period. Postmortem quantitative assessment of Golgi-impregnated pyramidal neurons in BA9 showed that apical dendritic length and trunk spine density were increased in D1 antagonist treated monkeys relative to AMPH-sensitized and AMPH-naive monkeys. These findings, which suggest that the deleterious consequences of AMPH sensitization can be reversed by modulation of D1 receptor signaling, have implications for treating the underlying neural basis of cognitive deficits in both schizophrenia and substance abuse.
Price-cost margins and foreign trade in U.S. textile and apparel industries: An analysis of pooled cross-section and time-series data

Abstract This study finds an unexpected, positive and significant association between price-cost margins and import-domestic shipment ratio for the U.S. textile and apparel industries, using pooled cross-section and time-series data. Distortions created by import quotas account for this anomalous finding.
Stimulation of epidermal growth factor gene expression during the fetal mouse reproductive tract differentiation: role of androgen and its receptor.

We have shown previously that epidermal growth factor (EGF) plays a role in testosterone-dependent fetal Wolffian duct differentiation. To further assess the role for EGF, we determined whether EGF gene expression was modulated in response to male reproductive tract differentiation. The expression of EGF messenger RNA (mRNA) was measured by an RT-PCR assay using primer pairs spanning the coding sequence of 3228 nucleotide (nt) to 3401 nt. Using the RT-PCR reaction, an amplimer of the expected size, 173 bp, was detected in the fetal male reproductive tract. The amplimer hybridized with a radioactive probe representing an internal sequence of the amplified product and was digested by the restriction enzyme HaeIII, which has an unique cleavage site at 3365 nt. The level of EGF mRNA at different stages of sexual differentiation was measured by a newly developed quantitative competitive RNA PCR (QCPCR) assay for EGF mRNA. The assay was sensitive and reproducible within a linear range of amplification with 5 x ...
Numerical approximation of the first eigenpair of the p-Laplacian using finite elements and the penalty method

For 1 consider the eigenvalue problem for the p-Laplacian where . The first eigenvalue λ 1 can be obtained by minimizing the functional over . A method for computing λ 1 numerically is presented. The technique uses a finite element approximation to the first eigenfunction and a penalty function to enforce the constraint. Convergence is proved and numerical results are presented. The numerical results are compared with exact values when known. A lower bound for p -Laplacian eigenvalues is also presented. In particular, this work provides a computational framework for obtaining precise approximations of the best constant for the Sobolev imbedding .
Steroid 21-hydroxylase activity in the ovary of the snake Storeria dekayi during pregnancy

Abstract The steroidogenic profiles of the corpora lutea and the remaining ovarian tissue from the snake Storeria dekayi at early and midpregnancy were compared after incubation with [4- 14 C] pregnenolone. Both tissues produced the following metabolites identified by their isopolarity and isomorphicity with standard compounds: 17α-hydroxypregnenolone, progesterone, 11-deoxycorticosterone, androstenedione, and testosterone. The steroids 17α-hydroxyprogesterone and dehydroepiandrosterone were not detected. Integration of the yield-time curves showed that much more 11-deoxycorticosterone and progesterone were synthesized by the corpora lutea at both stages of pregnancy than by the remaining ovarian tissue, whereas the latter produced more androstenedione and testosterone. Steroid 21-hydroxylase activity was almost exclusively confined to the luteal tissue. The corpora lutea at midpregnancy were smaller but showed greater steroid-converting activity per unit weight of tissue than those at early pregnancy. It is suggested that 11-deoxycorticosterone secretion may be involved in the function of the corpus luteum which is, supposedly, essential for embryonic survival during early pregnancy in some viviparous snakes.
Physiological, Ecological, and Phylogenetic Characterization of Stappia, a Marine CO-Oxidizing Bacterial Genus

Bacteria play a major role in marine CO cycling, yet very little is known about the microbes involved. Thirteen CO-oxidizing Stappia isolates obtained from existing cultures, macroalgae, or surf samples representing geographically and ecologically diverse habitats were characterized using biochemical, physiological, and phylogenetic approaches. All isolates were aerobic chemoorganotrophs that oxidized CO at elevated (1,000 ppm) and ambient-to-subambient concentrations (<0.3 ppm). All contained the form I (OMP) coxL gene for aerobic CO dehydrogenase and also the form II (BMS) putative coxL gene. In addition, some strains possessed cbbL, the large subunit gene for ribulose-1,5-bisphosphate carboxylase/oxygenase, suggesting the possibility of lithotrophic or mixotrophic metabolism. All isolates used a wide range of sugars, organic acids, amino acids, and aromatics for growth and grew at salinities from 5 to 45 ppt. All but one isolate denitrified or respired nitrate. Phylogenetic analyses based on 16S rRNA gene sequences indicated that several isolates could not be distinguished from Stappia aggregata and contributed to a widely distributed species complex. Four isolates (of strains GA15, HI, MIO, and M4) were phylogenetically distinct from validly described Stappia species and closely related genera (e.g., Ahrensia, Pannonibacter, Pseudovibrio, and Roseibium). Substrate utilization profiles, enzymatic activity, and membrane lipid composition further distinguished these isolates and supported their designations as new Stappia species. The observed metabolic versatility of Stappia likely accounts for its cosmopolitan distribution and its ability to contribute to CO cycling as well as other important biogeochemical cycles.
Lupron retards proliferation of ovarian epithelial tumor cells cultured in serum-free medium.

Some patients with recurrent ovarian epithelial cancer respond favorably to treatment with GnRH agonists. This effect was proposed to be mediated by suppression of pituitary gonadotropin release. The present in vitro study investigated effects of human gonadotropin (Pergonal LH/FSH, 1:1) and Lupron, a GnRH agonist, on proliferation of an ovarian cancer cell line, 2774, which is estrogen receptor negative and grows well in serum-free, defined medium. Pergonal, 10 IU/mL or 30 IU/mL, did not enhance cell proliferation, which argues against stabilization of ovarian tumors in vivo due to decreased serum gonadotropin. Lupron, 1.4 μg/mL and 140 μg/mL, retarded cell division by day 6–8 of culture, in a dose-dependent manner. Flow cytometric cell cycle phase DNA analysis demonstrated Lupron caused a reversible 5–6% increase in the portion of cells in rest phase, G0/G1, compared to controls during log growth, and a corresponding decrease in the portion of cells in DNA synthesis, S phase. However, long-term culture,...
Equilibrium and formation/dissociation kinetics of some Ln IIIPCTA complexes

The protonation constants ( ) of 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene-3,6,9-triacetic acid (PCTA) and stability constants of complexes formed between this pyridine-containing macrocycle and several different metal ions have been determined in 1.0 M KCl at 25 °C and compared to previous literature values. The first protonation constant was found to be 0.5−0.6 log units higher than the value reported previously, and a total of five protonation steps were detected (log = 11.36, 7.35, 3.83, 2.12, and 1.29). The stability constants of complexes formed between PCTA and Mg2+, Ca2+, Cu2+, and Zn2+ were also somewhat higher than those previously reported, but this difference could be largely attributed to the higher first protonation constant of the ligand. Stability constants of complexes formed between PCTA and the Ln3+ series of ions and Y3+ were determined by using an “out-of-cell” potentiometric method. These values ranged from log K = 18.15 for Ce(PCTA) to log K = 20.63 for Yb(PCTA), i...
Active vibration control with model correction on a flexible laboratory grid structure

This paper presents experimental and computational comparisons of three active damping control laws applied to a complex laboratory structure. Two reduced structural models were used with one model being corrected on the basis of measured mode shapes and frequencies. Three control laws were investigated, a time-invariant linear quadratic regulator with state estimation and two direct rate feedback control laws. Experimental results for all designs were obtained with digital implementation. It was found that model correction improved the agreement between analytical and experimental results. The best agreement was obtained with the simplest direct rate feedback control.
A pole to pole west Pacific atmospheric teleconnection during August

[1] An observational analysis is presented that reveals an August teleconnection involving both the Northern Hemisphere (NH) and the Southern Hemisphere (SH). The teleconnection includes three primary anomalies in the monthly average surface pressure field: (1) a high southern latitude component including Wilkes Land, Antarctica, the nearby Southern Ocean, and the Ross Sea, (2) a SH midlatitude component near Australia and New Zealand, and (3) a NH subtropical component over the extreme western Pacific Ocean. Surface pressure for the SH high-latitude anomaly is negatively correlated to the other two primary anomalies. The SH midlatitude and NH subtropical component are positively correlated. Furthermore, the teleconnection is correlated to surface pressure near the Aleutian Islands. The teleconnection anomalies result from tropical convection on intraseasonal timescales. Monsoon rainfall over East Asia during August is correlated to the teleconnection. Furthermore, August precipitation at several other locations in the NH and SH is modulated by the teleconnection. Two different sets of numerical experiments with the National Center for Atmospheric Research (NCAR) Community Climate Model version 2 (CCM2) show a similar-appearing teleconnection during late boreal summer. The modeled teleconnection, however, is forced from high southern latitudes.
Commutative rings for which every continuous module is quasi-injective

1. Introduction. The concept of continuous modules owes its origin to Von Neumann's work on continuous geometries [16], and Utumi's work on continuous rings ([12], [13], [14]). L. Jeremy in [3] defined continuous modules, and others ([2], [5], [6], [7], [10]) later provided many interesting properties of such modules. A module is called continuous if (i) every submodule is essential in a summand and (ii) every submodule, isomorphic to a summand, is itself a summand. It can be easily seen, that while every quasi-injective module is continuous ([3], [5], [10]), the converse is not true. It is, therefore, natural to ask: For what classes of rings, is every continuous module quasi-injective? We provide here some classes of commutative rings, for which this is true. Our study is motivated by a general interest in identifying rings for which continuity is a non-trivial concept, and specifically, because only for such rings the existence of continuous hulls [7] poses a problem. We show that large classes of commutative rings, such as noetherian ones, and semiprimary ones with Jacobson radical square zero, have the property that every continuous module is quasi-injective. We give a necessary and sufficient condition, over an arbitrary commutative ring, for every uniform continuous module to be quasi-injective. We also provide necessary and sufficient conditions for some special classes of commutative rings, such as perfect rings, finitary rings, and chain rings, to have the property that every continuous module is quasi-injective. All our rings are commutative, have identity elements, and all modules are unitary rightmodules. Homomorphisms and endomorphisms act on the left. E(M)= EM denotes the injective hull of a module M. A c'M means that A is an essential submodule of M, a "summand" means a "direct summand", and e ~ stands for the annihilator in R of an element e of an R-module. A module A is said to be B-injective if every homomorphism from a submodule of B to A can be extended to B. We recall that a module M is called quasi-continuous (or 7r-injective) if M is closed under all idempotents of EndoRE(M) ([2], [3]). This holds if and only if every decomposition E(M)-- ~ @ E, induces a decomposition M= ~ @ (M hE,) tel tel ([2], Theorem 1.1). Every continuous module is quasi-continuous, and every quasi-continuous module satisfies the condition (i) of the definition of a continuous module. Let Mbe a module, with an injective hull E, then a continuous overmodule C of Mis called a continuous hull of M if Mc C ~ E, and if C c X holds for every continuous module M= X c E. We mention that this definition is independent of the choice of E [7].
Neotropical human–landscape interactions, fire, and atmospheric CO2 during European conquest:

Neotropical biomass burning reconstructions synthesized from soil and sedimentary charcoal records indicate a period of reduced biomass burning sustained for several centuries after ~500 cal. yr BP. Proxy records of solar irradiance, El Nino events, temperature, and precipitation document regionally variable climate-related trends that do not account for the uniform reduction in burning across the Neotropics. Decreased human ignition resulting from pandemic-induced mortality offers an alternative, geographically comprehensive explanation. In addition, natural (solar-volcanic) factors can explain only ~1.3 ppm out of the rapid 6–10 ppm CO2 decrease between ad 1525 and the early 1600s. Reforestation following land abandonment due to population collapse has the potential to account for the rest of this CO2 decline, and variations in the 13C/12C of atmospheric CO2 and CH4 are consistent with both a major reduction in Neotropical landscape management by fire and massive reforestation. Our findings are demonstr...
Ontogenetic changes in potassium transport in xylem of tomato

The influence of plant ontogeny on xylem exudate K+ concentrations and K+ transport to the shoot was studied in both nutrient-solution and field-grown tomato plants (Lycopersicon esculentum). K+ concentrations in xylem exudate from decapitated plants decreased during tomato plant development from a high of 12 mM to a low of 5 mM. In the nutrient-solution plants, the most rapid decline occurred during the vegetative growth phase, while in field-grown plants, the xylem K+ concentrations remained high during an-thesis and then subsequently declined. The rapid decline in nutrient-solution plants might be related to a decrease in the absorptive efficiency of the root system. In field-grown plants, a reduction in the availability of assimilates to the root might account in part for the decrease in xylem exudate K+ concentrations. The volume (ml h−1 plant−1) and the net rates of K+ exudation (mmol h−1 plant−1) decreased dramatically as the fruits approached maturity. Since only a small reduction in xylem exudate K+ concentrations occurred during fruiting, the hydraulic conductivity of the root system decreased as the tomato plants aged. It is proposed that the ontogenetic changes in xylem transport of K+ contribute to a reduction in leaf free space K+ concentration which would explain the decline in tomato leaf K+ concentrations.
Electroreflectance and photoinduced charge seperation in eletrochemically doped trans-polyacetylene liquid junction device

Abstract Liquid junction solar cells, made from electrochemically doped p-type trans-polyacetylene in contact with aqueous solution of methyl viologen, were constructed. The turn-on potential was found to be +1.0 V versus SCE. The spectral response showed low quantum efficiency (≈10 −4 ) for photoinduced charge separation with a threshold around 1.5 eV. The electroreflectance showed the presence of two transitions at 1.45 and at 1.6 eV. A tentative assignment of these transitions is proposed.
Atomic K-, L-, and M-shell cross sections for ionization by protons: A relativistic hartree-slater calculation

Abstract Relativistic direct ionization cross sections for proton impact have been evaluated with Dirac-Hartree-Slater wave functions for atomic K , L , and M shells. Corrections for binding, polarization, and Coulomb deflection are included. Results are tabulated for proton energies from 3.25 to 5 MeV for the K shell and 1 to 5 MeV for the L subshells, for 28 elements with atomic numbers 22 ⩽ Z ⩽ 92. For M -subshell cross sections, results are tabulated for 15 elements with 54 ⩽ Z ⩽ 92, for proton energies from 0.06 to 2 MeV.
Signals, timers, and continuations for multithreaded user-level protocols

Precise timing and asynchronous IsO are appealing features for many applications. Unix kernels provide such features on a per-process basis, using signals to communicate asynchronous events to applications. Per-process signals and timers are grossly inadequate for complex multithreaded applications that require per-thread signals and timers that operate at finer granularity. To respond to this need, we present a scheme that integrates asynchronous (Unix) signals with user-level threads, using the A RIADNE system as a platform. This is done with a view towards support for portable, multithreaded, and multiprotocol distributed applications, namely the C LAM (connectionless, lightweight, and multiway) communications library. In the same context, we propose the use of continuations as an efficient mechanism for reducing thread context-switching and busy-wait overheads in multithreaded protocols. Our proposal for integrating timers and signal-handling mechanisms not only solves problems related to race conditions, but also offers an efficient and flexible interface for timing and signalling threads. Copyright © 2006 John Wiley & Sons, Ltd.
The effect of pulse duration on laser-induced damage by 1053-nm light in potassium dihydrogen phosphate crystals

Laser induced damage in potassium dihydrogen phosphate (KDP) has previously been shown to depend significantly on pulse duration for 351-nm Gaussian pulses. In this work we studied the properties of damage initiated by 1053-nm temporally Gaussian pulses with 10ns and 3ns FWHM durations. Our results indicate that the number of damage sites induced by 1053-nm light scales with pulse duration ({tau}) as ({tau}{sub 1}/{tau}{sub 2}){sup 0.17} in contrast to the previously reported results for 351-nm light as ({tau}{sub 1}/{tau}{sub 2}){sup 0.35}. This indicates that damage site formation is significantly less probable at longer wavelengths for a given fluence.
Kinetics of the Internal Oxidation of (Mg, Fe)O Solid Solutions

Single crystals of Mg1-xFexO,x= 0.01, have been oxidized in air at temperatures between 1146 and 1389 K to determine the kinetics of the internal oxidation reaction. A two-phase region composed of MgFe2O4 precipitates in a (Mg, Fe)O matrix grows inward from the surface as the reaction progresses. The thickness of this layer as a function of time has been determined by optical microscopy; the growth kinetics are parabolic. In addition, an external oxide layer of (Mg, Fe)O grows outward from the original surface. The thickness of this external oxide layer as a function of time was determined by following the displacement of inert markers with Rutherford backscattering spectrometry; the kinetics of the growth of this external layer are also parabolic in time. The parabolic reaction rate constant determined for the growth of the external layer accurately predicts that for the growth of the internally oxidized region.
Cellular neural networks with non-linear and delay-type template elements and non-uniform grids

The cellular neural network (CNN) paradigm is a powerful framework for analogue non-linear processing arrays placed on a regular grid. In this paper we extend the current repertoire of CNN cloning template elements (atoms) by introducing additional non-linear and delay-type characteristics. In addition, architectures with non-uniform processors and neighbourhoods (grid sizes) are introduced. With this generalization, several well-known and powerful analogue array-computing structures can be interpreted as special cases of the CNN. Moreover, we show that the CNN with these generalized cloning templates has a general programmable circuit structure (a prototype machine) with analogue macros and algorithms. the relations with the cellular automaton (CA) and the systolic array (SA) are analysed. Finally, some robust stability results and the state space structure of the dynamics are presented.
Life Cycle Comparison of Two Options for MSW Management in Puerto Rico: Thermal Treatment vs. Modern Landfilling

The management of municipal solid wastes (MSW) in Puerto Rico is becoming increasingly challenging. In recent years, several of the older landfills have closed due to lack of compliance with federal landfill requirements. Puerto Rico is an island community and there is limited space for construction of new landfills. Furthermore, Puerto Rico residents generate more waste per capita than people living on the continental US. Thermal treatment, or waste to energy (WTE) technologies are therefore a promising option for MSW management. It is critical to consider environmental impacts when making decisions related to MSW management. In this paper we quantify and compare the environmental implications of thermal treatment of MSW with modern landfilling for Puerto Rico from a life cycle perspective. The Caguas municipality is currently considering developing a thermal treatment plant. We compare this to an expansion of a landfill site in the Humacao municipality, which currently receives waste from Caguas. The scope of our analysis includes a broad suite of activities associated with management of MSW. We include: (i) the transportation of MSW; (ii) the impacts of managing waste (e.g., landfill gas emissions and potential aqueous run-off with landfills; air emissions of metals, dioxins and greenhouse gases) and (iii) the implications of energy and materials offsets from the waste management process (e.g., conversion of landfill gas to electricity, electricity produced in thermal treatment, and materials recovered from thermal treatment ash). We developed life cycle inventory models for different waste management processes, incorporating information from a wide range of sources — including peer reviewed life cycle inventory databases, the body of literature on environmental impact of waste management, and site-specific factors for Puerto Rico (e.g. waste composition, rainfall patterns, electricity mix). We managed uncertainty in data and models by constructing different scenarios for both technologies based on realistic ranges of emission factors. The results show that thermal treatment of the unrecyclable part of the waste stream is the preferred option for waste management when compared to modern landfilling. Furthermore, Eco-indicator 99 method is used to investigate the human health, ecosystem quality and resource use impact categories.Copyright © 2008 by ASME
Candida glabrata PDR1, a Transcriptional Regulator of a Pleiotropic Drug Resistance Network, Mediates Azole Resistance in Clinical Isolates and Petite Mutants

Candida glabrata, a yeast with intrinsically low susceptibility to azoles, frequently develops increased azole resistance during prolonged treatment. Transposon mutagenesis revealed that disruption of CgPDR1 resulted in an 8- to 16-fold increase in fluconazole susceptibility of C. glabrata. CgPDR1 is a homolog of Saccharomyces cerevisiae PDR1, which encodes a transcriptional regulator of multidrug transporters. Northern blot analyses indicated that CgPDR1 regulated both constitutive and drug-induced expression of CgCDR1, a multidrug transporter gene. In agreement with the Northern analysis, the Cgpdr1 mutant had increased rhodamine accumulation, in contrast to the decreased accumulation in the CgPDR1-overexpressing strain. Northern analyses also indicated the importance of CgPDR1 in fluconazole resistance arising during therapy. Two clinically resistant isolates had higher expression of CgPDR1 and CgCDR1 compared to their paired susceptible isolates. Integrative transformation of CgPDR1 from the two resistant isolates converted the Cgpdr1 mutant into azole-resistant strains with upregulated CgPDR1 expression. Two different amino acid substitutions, W297S in one isolate and F575L in the other, accounted for the upregulated CgPDR1 expression and the resistance. Finally, CgPDR1 was shown to be required for the azole resistance due to mitochondrial deficiency. Thus, CgPDR1 encodes a transcriptional regulator of a pleiotropic drug resistance network and contributes to the azole resistance of clinical isolates and petite mutants.
Telomere-Driven Tetraploidization Occurs in Human Cells Undergoing Crisis and Promotes Transformation of Mouse Cells

Human cancers with a subtetraploid karyotype are thought to originate from tetraploid precursors, but the cause of tetraploidization is unknown. We previously documented endoreduplication in mouse cells with persistent telomere dysfunction or genome-wide DNA damage. We now report that endoreduplication and mitotic failure occur during telomere crisis in human fibroblasts and mammary epithelial cells and document the role of p53 and Rb in repressing tetraploidization. Using an inducible system to generate transient telomere damage, we show that telomere-driven tetraploidization enhances the tumorigenic transformation of mouse cells. Similar to human solid cancers, the resulting tumors evolved subtetraploid karyotypes. These data establish that telomere-driven tetraploidization is induced by critically short telomeres and has the potential to promote tumorigenesis in early cancerous lesions.
Soot distribution in turbulent nonpremixed chloromethane — Air flames

Abstract The results of an experimental study on soot and temperature distribution in turbulent, nonpremixed chloromethane-air jet flames are presented. Transient measurements of soot volume fraction and temperature are made using a three-line optical pyrometry method. This method enables measurement of the “total” (i.e., absorption-related), and “hot” (i.e., emission-related) soot. Significant amounts of cold soot with hot soot is observed to coexist for all of the measurements made in these flames. Images of soot presence using a gated camera provide information about the mixing phenomena. The effects due to differential probe lengths are also discussed.
Towards Cooperative Bayesian Human-Robot Perception: Theory, Experiments, Opportunities

Robust integration of robotic and human perception abilities can greatly enhance the execution of complex informationdriven tasks like search and rescue. Our goal is to formally characterize and combine diverse information streams obtained from multiple autonomous robots and humans within a unified probabilistic framework that naturally supports autonomous perception, human situational awareness, and cooperative human-robot task execution under stochastic uncertainties. This approach requires welldesigned human-robot interfaces, flexible and accurate probabilistic models for exploiting “human sensor” data, and sophisticated Bayesian inference methods for efficient learning and online dynamic state estimation. We review some of recent theoretical developments and insights from experiments using real human-robot teams, and discuss some open challenges for future research.
Inhibition of p38 by Vitamin D Reduces Interleukin-6 Production in Normal Prostate Cells via Mitogen-Activated Protein Kinase Phosphatase 5: Implications for Prostate Cancer Prevention by Vitamin D

Although numerous studies have implicated vitamin D in preventing prostate cancer, the underlying mechanism(s) remains unclear. Using normal human prostatic epithelial cells, we examined the role of mitogen-activated protein kinase phosphatase 5 (MKP5) in mediating cancer preventive activities of vitamin D. Up-regulation of MKP5 mRNA by 1,25-dihydroxyvitamin-D3 (1,25D) was dependent on the vitamin D receptor. We also identified a putative positive vitamin D response element within the MKP5 promoter that associated with the vitamin D receptor following 1,25D treatment. MKP5 dephosphorylates/inactivates the stress-activated protein kinase p38. Treatment of prostate cells with 1,25D inhibited p38 phosphorylation, and MKP5 small interfering RNA blocked this effect. Activation of p38 and downstream production of interleukin 6 (IL-6) are proinflammatory. Inflammation and IL-6 overexpression have been implicated in the initiation and progression of prostate cancer. 1,25D pretreatment inhibited both UV- and tumor necrosis factor α–stimulated IL-6 production in normal cells via p38 inhibition. Consistent with inhibition of p38, 1,25D decreased UV-stimulated IL-6 mRNA stabilization. The ability of 1,25D to up-regulate MKP5 was maintained in primary prostatic adenocarcinoma cells but was absent in metastases-derived prostate cancer cell lines. The inability of 1,25D to regulate MKP5 in the metastasis-derived cancer cells suggests there may be selective pressure to eliminate key tumor suppressor functions of vitamin D during cancer progression. These studies reveal MKP5 as a mediator of p38 inactivation and decreased IL-6 expression by 1,25D in primary prostatic cultures of normal and adenocarcinoma cells, implicating decreased prostatic inflammation as a potential mechanism for prostate cancer prevention by 1,25D. (Cancer Res 2006; 66(8): 4516-24)