cssi/SciSciGPT-SciSciNet huggingface dataset:
Patogênese molecular do feocromocitoma

Feocromocitoma e um tumor raro originario de celulas neuroectodermicas. Em aproximadamente 10% dos casos, estes tumores sao herdados. Existem multiplas formas familiares de feocromocitomas, entre as quais a neoplasia endocrina do tipo 2, a sindrome de von Hippel Lindau, a neurofibromatose tipo 1, formas familiares isoladas de feocromocitoma e possivelmente outros subtipos menos bem caracterizados. Ao mesmo tempo em que se tem observado nos ultimos anos um importante avanco quanto a definicao do defeito genetico responsavel pela maior parte das sindromes hereditarias associadas ao feocromocitoma, houve pouco progresso na caracterizacao da patogenese molecular das variantes esporadicas destes tumores, assim como em grande parte das formas familiares isoladas. Esta revisao apresenta um resumo dos aspectos moleculares das diversas formas de feocromocitomas familiares e esporadicos e finaliza com a proposicao de estudos futuros que possam contribuir para elucidar alguns dos muitos aspectos da genese deste tumor que ainda permanecem obscuros.
A METHOD FOR BASELINING AND IMPROVING AN ORGANIZATIONS SYSTEMS ENGINEERING CAPABILITY

A fundamental premises of this paper is that the system engineering capability of an organization can only be as good as the collective skills of the individuals that make up the organization. This paper describes two distinct career paths for systems engineers, system integration and system analyst. Thirty-five skill areas are identified for the system integration path, and twenty for the system analyst path. In addition, basic system engineering skills required for both career paths are described. Four levels of expertise are described for the two different career paths. Skill level ratings are determined for individuals in each skill area that applies. Collectively, these individual ratings are used as an indicator of the system engineering capability of an organization. Individual career development is based on achieving higher skill levels in the skill areas. The system engineering capability of an organization is improved as individuals achieve higher skill levels.
Open Versus Minimally Invasive Esophagectomy: What is the Best Approach? Minimally Invasive Esophagectomy

Introduction Esophageal cancer is a complex disease that is typically discovered at a late stage and is associated with a poor overall survival rate.
Tongue piercing. The new "rusty nail"?

Background Cephalic tetanus is a rare form of the tetanus caused primarily by wounds or other infectious processes involving the head and neck. This condition frequently progresses to the generalized form of tetanus with the attendant risks and complications. Methods A case report of a young female who developed an unusual form of tetanus after a tongue piercing is presented here. We discuss this disorder as it applies to the contemporary caregiver with a focus on its presentation and recognition. Results A delay in diagnosis of 13 days from presentation occurred. The patient had a slow, uneventful but incomplete recovery course. She never developed significant airway compromise, nor did she demonstrate any evidence of hemodynamic instability but continued to have right facial weakness up to 6 months after discharge. Conclusions A few factors were identified that contributed to the significant delay in diagnosis. The unusual nature of the disease and a lowered index of suspicion on the part of the initial caregivers were probably the major causes. Fortunately, no major adverse sequelae resulted from the delay. However, if this case heralds the onset of a rise in the incidence of tetanus, early recognition and diagnosis would seem essential to avoid much of the morbidity and mortality associated with the disease. © 2000 John Wiley & Sons, Inc. Head Neck 22: 728–732, 2000.
Limited access to ethanol increases the number of spontaneously active dopamine neurons in the posterior ventral tegmental area of nondependent P rats

Microdialysis experiments in alcohol-preferring (P) rats have shown that chronic ethanol exposure increases extracellular levels of dopamine (DA) in the nucleus accumbens. Because DA neuronal activity contributes to the regulation of DA overflow in terminal regions, we hypothesized that posterior ventral tegmental area (VTA) DA neuronal activity (firing frequency, burst activity, and/or the number of spontaneously active DA neurons) would be increased in P rats consuming ethanol compared with P rats consuming only water. In vivo electrophysiological techniques were used to evaluate the activity of single DA neurons in the posterior VTA. Our findings show that voluntary ethanol intake by nondependent P rats significantly increased the number of spontaneously active DA neurons in the posterior VTA compared with P rats that consumed only water. Firing frequency and burst activity did not differ between the two groups. These results suggest that adaptive changes occur in the mesolimbic DA system of nondependent P rats to increase the excitability of posterior VTA DA neurons and enhance DA release from nerve terminals in the nucleus accumbens.
Heads in the cloud

A professor and several PhD students at MIT examine the challenges and opportunities in human computation.
The Role of Temperature in the Entanglement Kinetics of a Polymer Melt

Large-amplitude oscillatory shear (LAOS) experiments were conducted at different temperatures on a molten low-density polyethylene standard, designated IUPAC LDPE X. Jeyaseelan et al. (1993) have successfully employed a simplification of transient network theory to describe the LAOS behavior of this polymer melt, at 150°C. The transient network is described by two kinetic rate constants, one for the formation of entanglements due to Brownian motion (k 1 ), and another for the destruction of entanglements (k 2 ) due to the imposed deformation. Upon comparison of the predictions of this transient network theory with the measured LAOS behavior of this polymer, we find that the kinetic rate constants k 1 and k 2 are invariant in the range of temperatures examined (150 to 190°C). The temperature dependence of departures from linear viscoelasticity is fully accounted for in the equilibrium entanglement kinetics.
Design of e-pharmacophore models using compound fragments for the trans-sialidase of Trypanosoma cruzi: screening for novel inhibitor scaffolds.

Chagas’ is a fatal disease that affects millions of people worldwide. The lack of safe and effective treatments for Chagas’ highlights the need for the discovery of new drugs to fight the disease. Trypanosoma cruzi, the parasitic cause of Chagas’ disease, synthesizes a trans-sialidase (TcTS) enzyme responsible for the transfer of sialic acids from the host cell surface to glycoconjugates on the parasitic cell surface. TcTS has no human analogs and is vital to the life cycle of T. cruzi, making TcTS an important enzyme for drug design against Chagas’ disease. We use fragment docking to generate various e-pharmacophore hypotheses depicting protein residues important for ligand binding. Virtual screening of the ZINC Clean Leads database with more than 4 million compounds using the e-pharmacophore models found 82 potential inhibitors of TcTS. Molecular dynamics and free energy of binding calculations were used to rank the compounds based on their affinity for TcTS. Two compounds—ZINC13359679 and ZINC02576132—were found to be the most promising lead candidates for TcTS inhibition, and their binding modes are analyzed in detail.
The effects of crescendo on vocal vibrato

Summary The purpose of this research was to investigate the effects of crescendo and decrescendo on the width of vocal vibrato. A second interest was whether the frequency at which the crescendo or decrescendo occurred would be a factor. Nine singers each produced nine phonations. The first set of three phonations was crescendo from pp to ff at low, medium, and high frequency. The second set of three was decrescendo from ff to pp at the three frequencies and the third set was from pp to ff to pp at each frequency. The vibrato width during each phonation was measured via a Kay Visipitch. The results generally indicated that vibrato width increased with increasing crescendo. With decrescendo, however, the vibrato width tended to remain constant even though the intensity was decreasing. The greatest vibrato width occurred at the middle frequencies.
A pilot study of the personality assessment inventory (PAI) in corrections: assessment of malingering, suicide risk, and aggression in male inmates

Provision of mental health services to correctional populations places considerable demands on clinical staff to provide efficient and effective means to screen patients for severe mental disorders and other emergent conditions that necessitate immediate interventions. Among the highly problematic behaviors found in correctional settings are forms of acting out (e.g., suicide and aggression towards others) and response style (e.g., motivations to malinger). The current study examined the usefulness of the Personality Assessment Inventory (PAI) in assessing problematic behaviors in a corrections-based psychiatric hospital. As evidence of criterion related validity, selected PAI scales were compared to (a) evidence of malingering on the Structured Interview of Reported Symptoms (SIRS), (b) suicidal threats and gestures, and (c) ratings of aggression on the Overt Aggression Scale (OAS). In general, results supported the use of the PAI for the assessment of these problematic behaviors.
Coordinate-invariant regularization

Abstract A general phase-space framework for coordinate-invariant regularization is given. The development is geometric, with all regularization contained in regularized DeWitt superstructures on field deformations. Parallel development of invariant coordinate-space regularization is obtained by regularized functional integration of the momenta. As representative examples of the general formulation, the regularized general non-linear sigma model and regularized quantum gravity are discussed.
Analysis of syn- and anti-1,2-dihydroxy-3,4-epoxy-1,2,3,4-tetrahydro-5-methylchrysene-deoxyribonucleoside adducts by boronate chromatography

Abstract The Servacel DHB ( m -dihydroxyborylphenylaminoethyl cellulose) chromatographic procedure developed by Sawiki et al. (Cancer Res., 43, 3212–3218, 1983) for analysis of 7,12-dimethylbenz[ a ]anthracene (DMBA)-DNA adducts was applied to analyze syn - and anti -1,2-dihydroxy-3,4-epoxy-1,2,3,4-tetrahydro-5-methylchrysene (DE-I)-deoxyribonucleoside adducts. Identical elution conditions to whose developed for the DMBA adducts were employed. While the results were similar to those obtained in the DMBA system, some of the anti -DE-I-deoxyribonucleoside adducts eluted with the buffer system used for elution of syn -adducts. Complete resolution of the anti - and syn -adducts was obtained when modified elution conditions as developed by Pruess-Schwartz et al. (Cancer Res., 44, 4104–4110, 1984) for analysis of syn - and anti -7α-8β-dihydroxy-9β, 10β-epoxy-7,8,9,10-tetrahydrobenzo[ a ]pyrene—DNA adducts were applied. Based on this chromatographic procedure about 15% of the DE-I deoxyribonucleoside adducts, formed in mouse skin DNA upon treatment with 5-[ 3 H]methylchrysene (MeC), originated from syn -DE-I.
Microarray analysis of regional dura mater and identification of a transcription factor regulating epithelial to mesenchymal cell transitions

Abstract Introduction: Although a wealth of data demonstrates that regionally patterned dura mater regulates suture fusion or patency, the onset and extent of this patterning remains unknown. In this study we used microarray analyses as a starting point to investigate the differences in suture-specific dura mater from the mouse posterior frontal (PF) and sagittal (SAG) suture. Methods: Regional dura mater was harvested from the PF and SAsutures of 15 and 25 day male CD-1 mice (n = 40 each) and RNA isolated. Microarray analyses were performed using 42,000 element cDNA arrays. Slug was also evaluated in non-suture dura from young (5-day-old) and adult (60-day-old) animals. Investigation into regulation of novel genes, such as the transcription factor Slug, were carried out using rat calvarial osteoblasts stimulated with FGF-2, TGF-beta 1, and BMP2 and 4. Results: Microarray analyses demonstrated differential regulation of over 220 genes in the PF suture at d15, and over 280 genes at d25. Although the number of genes down-regulated was similar, there was a dramatic increase in the number of genes up-regulated in the PF suture at d25 vs. d15 (137 vs. 43). Distinct patterns of expression were seen for several groups of genes, including cytokines (FGF and FGF receptors) and extra-cellular matrix molecules (Col-1, osteopontin, osteocalcin). Several novel genes were identified, including the transcription factor Slug. QRT-PCR verified a > 4-fold increase in Slug mRNA in PF vs. SAG dura, and a > 3-fold increase in young vs. adult dura mater. Functional studies demonstrated a selective inhibition of Slug mRNA in osteoblasts by FGF-2 and TGF-beta 1, but not the BMPs, up to 24 hrs post stimulation (see figure). Conclusions: Our data demonstrate genomic patterning of regional dura mater as early as ten days prior to PF suture fusion. In addition we show that the transcription factor Slug, an evolutionarily conserved gene involved in epithelial-to-mesenchymal cell transitions, is regulated by two growth factors known to be expressed in dura mater.
Magnetization transfer effects on the efficiency of flow-driven adiabatic fast passage inversion of arterial blood

Continuous arterial spin labeling experiments typically use flow-driven adiabatic fast passage inversion of the arterial blood water protons. In this article, we measure the effect of magnetization transfer in blood and how it affects the inversion label. We use modified Bloch equations to model flow-driven adiabatic inversion in the presence of magnetization transfer in blood flowing at velocities from 1 to 30 cm/s in order to explain our findings. Magnetization transfer results in a reduction of the inversion efficiency at the inversion plane of up to 3.65% in the range of velocities examined, as well as faster relaxation of the arterial label in continuous labeling experiments. The two effects combined can result in inversion efficiency reduction of up to 8.91% in the simulated range of velocities. These effects are strongly dependent on the velocity of the flowing blood, with 10 cm/s yielding the largest loss in efficiency due to magnetization transfer effects. Flowing blood phantom experiments confirmed faster relaxation of the inversion label than that predicted by T(1) decay alone.
Oxidation of a Phospholipid at an Electrode Modified with an Electrochemically Formed Sol-Gel Film Doped with Cyclodextrin

In aqueous, un-buffered solution at a potential where H+ is generated in a tetraethylorthosilicate sol, nm-scale deposits of silica on electrodes are formed. Inclusion of β-cyclodextrin in the sol promotes electrochemical activity, presumably by producing channels in the otherwise-passivating film. With the additional provision of inclusion of a redox mediator, RhII, the electrochemical oxidation of a representative phospholipid (PL), phosphatidylcholine (PC), is demonstrated; the process occurs without the passivation that otherwise precludes the voltammetric determination of PLs. By cyclic voltammetry, current proportional to PC concentration in the range 1–100 μM is achieved with the described electrode.
Latency of a thymidine kinase-negative pseudorabies vaccine virus detected by the polymerase chain reaction

Latent viral DNA was detected by the polymerase chain reaction in trigeminal ganglia of all of 10 pigs that were necropsied 81 or more days after they had been infected intranasally with a thymidine kinase-negative (TK−) vaccine strain of pseudorabies virus (PRV). Failure to reactivate virus from any of the same pigs by earlier treatment with dexamethasone suggested that even though latency can be established with TK− PRV, subsequent reactivation may be a relatively rare event.
Lexical projection and the interaction of syntax and semantics in parsing

A series of self-paced reading studies utilized an embedded anomaly technique to investigate long-distance dependencies with dative verbs. Previous research i our lab demonstrated that argument structure influences the gap-filling process. Experiment I extended that work by demonstrating that dative verbs pattern with other complex transitive verbs (i.e., a fronted filler that is implausible as the direct object will not be interpreted as the direct object until the absence of a noun phrase after the verb forces the postulation of a direct object gap. This pattern contrasts with that of transitive verbs that subcategorize for a single internal argument position, where fronted fillers are obligatorily interpreted as the direct object). Experiments 2 and 3 investigate the prediction that semantic analyses precede syntactic analyses in dative questions. It is argued that the lexical information about argument structure and thematic roles can guide semantic interpretation.
Credit rationing when banks are funding constrained

Abstract Credit crunches, such as in the recent financial crisis, generally occur when banks are themselves funding constrained. We use this observation to repair the workhorse Stiglitz–Weiss model of credit rationing. Recent research has invalidated the distributional assumption on which that model is based. This paper shows that by adding the assumption that banks are capacity constrained, Stiglitz–Weiss rationing can occur again. It discusses how this finding can be related to the current policy debates on bank funding and credit provision.
Isolation and regulatory properties of two glutamate dehydrogenases from the cellular slime mold Dictyostelium discoideum.

Abstract Two distinct glutamate dehydrogenases are present in amoebae of the cellular slime mold Dictyostelium discoideum . One enzyme has been extracted from a crude mitochondrial fraction, and the other from an extramitochondrial cytoplasmic fraction. Both enzymes have been partially purified and characterized. The mitochondrial enzyme can utilize both NAD + and NADP + as coenzyme, while the extramitochondrial is NAD + specific. When the mitondrial enzyme is assayed in the presence of either a rate-limiting or saturating concentration of glutamate, its activity is stimulated by both AMP and ADP and is inhibited by ATP. When the extramitochondrial enzyme is assayed in the presence of a rate-limiting concentration of glutamate, its activity is sensitive to modulation by a number of intermediates in carbohydrate metabolism and is inhibited by ADP, ATP, GTP, and CTP.
Molybdenum geochemistry in a seasonally dysoxic Mo-limited lacustrine ecosystem

Lakes are important for storage of the essential micronutrient molybdenum (Mo) during its transfer from the continents to the oceans, but little is known about the major sources and sinks for Mo in lacustrine ecosystems. We studied Mo cycling in Castle Lake, a small subalpine lake in the Klamath-Siskiyou Mountains of Northern California underlain primarily by mafic and ultramafic rocks where primary productivity is limited by Mo bioavailability. The deeper water of the lake becomes dysoxic (9–90 μM dissolved oxygen) during the summer. This study was undertaken to identify the sources of Mo to Castle Lake and establish a Mo budget. We measured Mo concentrations in a suite of bulk solids (lake sediments, soils and bedrock) and aqueous samples (sediment porewaters, soil runoff, spring waters, snow and ice) from Castle Lake and its watershed. Lake sediments have elevated Mo (7–36 ppm) compared to soils and bedrock (0.2–2 ppm) and Mo/Al values were nearly two orders of magnitude higher than the crustal abundance. Sediment porewaters had higher Mo (4–15 nM) than lake water (2–4 nM), soil runoff (0.1–6.2 nM), snowmelt (⩽0.1 nM), lake ice (0.3–2.2 nM) and local spring waters (0.03–2.72 nM). Bulk lake sediments had negative δ^(98/95)Mo values, ranging from −0.5 to −1.0‰ (±0.1). We used the numerical model PROFILE to estimate the net reaction rate of Mo in the porewater. Model calculations ruled out diagenesis as a source of Mo to lake sediments; diagenetic Mo always represented ⩽5% of the total Mo content in sediment. We also ruled out dissolved Mo inputs from groundwater and watershed inflow as important sources of Mo. Two whole-lake experimental Mo additions in the 1960’s could have contributed a sizeable amount of Mo to the lake sediments, but only over a short period. Atmospheric deposition of anthropogenic Mo from extensive copper smelting that occurred south of Castle Lake from 1896 to 1919 and from major Californian urban centers today were negligible Mo sources. Mo flux from the sediments (0.4–0.5 nmol cm^(−2) yr^(−1)) was roughly equal to Mo fluxes from surface inflow and outflow, whereas Mo burial fluxes were significantly higher (11.5 nmol cm^(−2) yr^(−1)). Because dissolved Mo fluxes were minimal, and atmospheric Mo deposition was estimated to be a minor source of Mo (<1 nmol cm^(−2) yr^(−1)), the largest source of Mo is non-detrital particulate matter (∼12 nmol cm^(−2) yr^(−1)), likely a mixture of organic matter and Fe–Mn oxyhydroxides as supported by Mo isotopic data.
A new yield function for compressible PM materials

Abstract A new yield function for compressible P M materials has been derived based upon a yield criterion postulated by the authors. This function was experimentally verified for the uniaxial state of compressive stress using the P M aluminum alloy X7091 as a model material, and excellent agreement was found between theoretical and experimental results for the density dependence of the yield and geometrical hardening. Yield surfaces for various density levels have been generated in a three-dimensional principal-stress space using computer graphics.
Concentration polarization in ion exchange membrane electrodialysis

The distribution of NaCl concentration in the boundary layer formed on the desalting and concentrating surfaces of an ion exchange membrane was estimated theoretically and compared with values obtained by the Schlieren diagonal method. p]In the desalting chamber, if the convective flow rate (the flow rate component perpendicular to the membrane surface) on the desalting surface of the membrane exceeds a critical value, the NaCl concentration distribution in the boundary layer becomes uniform and takes on the value for the bulk solution. However, if the convective flow rate drops even slightly below the critical value, the NaCl concentration in the boundary layer decreases considerably at the membrane/ solution interface. p]In the concentrating chamber, the NaCl concentration in the boundary layer rises on the surface of a cation exchange membrane and falls on the surface of an anion exchange membrane. This is due to the diffusion constant of Cl− ions being larger than that of Na+ ions.
mGluR5 antagonism attenuates methamphetamine reinforcement and prevents reinstatement of methamphetamine-seeking behavior in rats.

mGluR5 Antagonism Attenuates Methamphetamine Reinforcement and Prevents Reinstatement of Methamphetamine-Seeking Behavior in Rats
What are the physiological estrogens

Estradiol (E2) is the principal physiological estrogen in mammals. E2 and its active metabolites, estrone and estriol have a characteristic phenolic A ring, unlike progesterone, testosterone, cortisol and aldosterone, which have an A ring containing a C3-ketone, a Δ(4) bond and a C19 methyl group. Crystal structures of E2 in the estrogen receptor (ER) confirm the importance of the A ring in stabilizing E2 in the ER. However, other steroids, including Δ(5)-androstenediol, 5α-androstanediol and 27-hydroxycholesterol, which have a saturated A ring containing a 3β-hydroxyl and a C19 methyl group, also mediate physiological responses through binding to estrogen receptor-α (ERα) and ERβ. Moreover, selective estrogen response modulators (SERMs) with diverse structures also regulate transcription of ERα and ERβ. Our understanding of the physiological responses mediated by these "alternative" estrogens is in its infancy. Further studies of the role of these steroids and SERMs in regulating responses mediated by ERα and ERβ a variety of tissues, during different stages of development, are likely to uncover additional estrogenic activities.
An introduction to the principles and applications of holography

Holography has strong historical ties with electrical engineering and potential application to many electrical engineering problems. The basic problem addressed by holography is introduced in both physical and mathematical terms. The analogy between the hologram of a point-source object and the linear FM signals of chirp radar is stressed, and the first-order imaging properties of holograms recorded in arbitrary geometries are derived. Various types of holograms are described, including thin, thick, transmission, reflection, amplitude, and phase holograms. The important properties of each type of hologram are introduced. A survey of various applications of holography is presented, with introductions to the use of holography in interferometry, microscopy, imaging through distorting media, optical data processing, and optical data storage. The use of simple holograms as optical elements is also described.
Novel organic ionic liquids (OILs) incorporating cations derived from the antifungal drug miconazole

The imidazole-ring containing antifungal drug miconazole reacts with a variety of alkyl iodides to form imidazolium cations. After anion metathesis with NaPF6, organic ionic liquids (OILs) are obtained. These new ionic liquids are believed to be the first to be derived from a bioactive molecule. One of the new OILs also exhibits lyotropic liquid crystalline behavior while inducing the gelation of benzene.
Oxidation of Hg 1−x Cd x Te studied with surface sensitive techniques

We report the use of surface sensitive electron spectroscopies to monitor the initial steps of formation of a native oxide on atomically clean cleaved Hgl-xCdxTe single crystal surfaces in ultrahigh vacuum (UHV). Here the oxide is formed by oxygen excited by the presence of an operating ion gauge. During the reaction, the composition of the surface region of the substrate was found to change, with a net loss of Hg from the surface. Parallel studies of the compositions of thick anodic oxides using sputter profiling techniques showed only small amounts of Hg in the anodic oxides.
Personal Digital Assistants to Collect Data on Animal Carcass Removal from Roadways

The increase in animal-vehicle collisions (AVCs) on U.S. roadways raises significant concerns for human safety, property damage and injury costs, and viability of wildlife populations. Valuable AVC data can be obtained from documentation of instances and locations of animal carcasses on the roadway, but most transportation organizations do not systematically record these data. In 2006, accidents reported by police in Virginia represented less than 14% of the 45,000 deer-vehicle collisions (DVCs) estimated from insurance industry claims. A project was carried out to test a personal digital assistant (PDA) enabled with a Global Positioning System (GPS) receiver for the collection and analyses of animal carcass removals from the roadway and to initiate the integration of this data collection method into regular practice by the Virginia Department of Transportation (VDOT). VDOT maintenance personnel collected 8 months of spatially accurate carcass removal data by using GPS-enabled PDAs. DVC estimates from thi...
DELBOEUF ILLUSIONS: CONTOUR OR SIZE DETECTOR INTERACTIONS?

Manipulations of contour lightness were shown to alter the magnitude and direction of the Delboeuf illusion. The data suggest that size detector rather than contour interactions create this visual anomaly.
Nonlinear Interaction of Panel Flutter with Harmonic Forcing Excitation

Abstract : The interaction characteristics of harmonic forcing excitation and panel flutter are studied analytically. Both linear and nonlinear solutions are investigated. Wide ranges of dynamic pressure and forcing frequency are covered such that subcritical responses (pure forced response), supercritical responses (forcing-flutter interaction), and the coexistence of both pure forced response and forcing-flutter interaction are studied. Results obtained by both harmonic balance and direct integration methods generally agree well. The technique developed here can be applied to other structural dynamics problems. (Author)
QSOLVE: A software system for analytically solving a wide variety of waiting line analysis problems

Abstract Various mathematical formulae, tables, charts, and graphs are available in texts and/or research articles dealing with queueing theory, and although a number of software packages for solving waiting line analysis problems exist they seldom go beyond elementary Poisson models, and are generally not readily available. This paper describes a software capable of solving a wide variety of queueing models such as Poisson queues with state dependent or non state dependent parameters, some Non Poisson queues, Priority queues, Bulk/Batch Arrival queues, and a number of other types of queueing models. QSOLVE is entirely menu driven, is written in FORTRAN 77, and requires no knowledge of programming to use. QSOLVE may be used to solve various types of Industrial Engineering problems, it is not a commercial package and will be made available to researchers and practitioners.
Transition probabilities in Nd(II) and the solar neodymium abundance

We have measured branching ratios for all the known transitions from nine levels in Nd+. We use the known mean lifetimes of four of these levels to compute transition probabilities for 60 transitions. We have measured the solar equivalent widths of 12 of these lines on the Preliminary Edition of the Kitt Peak Solar Atlas and compute a photospheric Nd abundance log(NNdNH)+12 = 1.26±0.14, using the solar model parameters of Righini and Rigutti based on the Mutschlecner model. The solar lines used in this computation are weak (Wλ<3×10-6), and the derived abundance has little dependence on the uncertainties of the solar model.
Assessing habitat utilization and rockfish (Sebastes spp.) biomass on an isolated rocky ridge using acoustics and stereo image analysis

For those marine fish species with specific habitat preferences, a habitat-based assessment may provide an alternative to traditional surveys. We conducted a habitat-based acoustic and stereo image stock assessment survey for rockfishes (Sebastes spp.) on a rocky ridge habitat in the eastern Bering Sea. Video analysis suggested that juvenile and adult rockfishes were more abundant on the seafloor in the rocky ridge area than on the surrounding sandy flats. Over the ridges, the distribution of rockfishes was uniformly low in the water column during nighttime surveys and higher during daytime surveys. The opposite pattern was observed in the video on the seafloor between night (high density) and day (lower density), indicating that fish in the water column during the day moved to the seafloor at night. Mean biomass of adult rockfishes for the rocky ridges was 1.54 × 104 tonnes based on acoustic data. The biomass of juvenile fish was estimated to be 9.2 × 102 tonnes. Utilization of similar survey methodologi...
A MICROMECHANICAL VIEW OF THE FRACTURE TOUGHNESS OF ICE

Fracture toughness tests have been performed on freshwater ice as a function of grain size, temperature, and loading rate. Results indicate that toughness increases as temperature and grain size decrease. Toughness is constavt with loading rate (K) aboye a critical loading rate, kt, which is temperature dependent. Below Kt the toughness increases as K decreases. The results are explained in terms of a micromechanical model.
Effects of atrial natriuretic factor on cyclic GMP content in the rat aortic smooth muscle: studies on the role of membrane Na+, K+-ATPase

SUMMARY 1. These studies were conducted to determine whether preservation of the functional integrity of the membrane, Na+,K+-stimulated ATPase is essential for the atrial natriuretic factor (r-ANF-8–33) to enhance guanosine 3′,5′-monophosphate (cGMP) content in the rat aortic smooth muscle. In freshly dissected rat aortic tissues, levels of cGMP were estimated using radioimmunoassay. 2. ANF (0.1 μmol/L in Krebs-Henseleit media) produced significant elevation in cGMP levels in the aortic smooth muscle when compared with that incubated in the control media, whereas suppression of Na+-pump with ouabain (1.0 mmol/L) and/or K+-free media did not produce any significant changes in the basal cGMP level; these two experimental manoeuvres did not prevent enhancement of cGMP by ANF. 3. Incubation of the tissues in the media containing ouabain plus vasoconstrictor concentrations of norepinephrine (0.3 μmol/L) also did not alter basal cGMP levels and did not prevent the ability of ANF to elevate cGMP. 4. These studies demonstrate that the antagonism by ouabain, of vasorelaxant effects of ANF (as reported in the literature) are not due to the prevention of the ability of ANF to enhance cGMP levels in the arterial smooth muscle. It is proposed that such an antagonism may be related to the actions of ouabain and ANF on diverse, and perhaps independent, mechanisms which affect Ca2+-fluxes across the cell membrane.
Model-independent error analysis of K -nucleus elastic scattering

Recent studies have demonstrated the enhanced sensitivity of K mesons to interior nuclear matter distributions compared to that of protons at similar momenta. An approximately model-independent error analysis technique, similar to that used in analyses of electron scattering data, has been applied to K -nucleus elastic scattering at 442 and 991 MeV. The primary result of this work is that the momentum transfer range and statistical quality of data necessary to provide meaningful new constraints on the distribution of nuclear matter in the interior of large nuclei is specified. The model dependence of this approach for hadron-nucleus scattering is considered and shown to be negligible.
Municipal Government-Nonprofit Sector Collaboration in Bulgaria: An Attitudinal Analysis

The worldwide phenomenon of devolution of power to local governments and growth of community nonprofit organizations increases opportunities for municipal government-nonprofit sector collaboration....
US Working-Class/Poverty-Class Divides:

In arguing for more finely nuanced and inclusive understandings of class in the USA, I write as a ‘poverty-class scholar’ articulating an identity, experience, marginality, and concomitant consciou...
Effects of vlsE Complementation on the Infectivity of Borrelia burgdorferi Lacking the Linear Plasmid lp28-1

The loss of linear plasmid lp28-1, which contains the vls antigenic variation locus, is associated with reduced infectivity of Borrelia burgdorferi in immunocompetent mice. The recombinant shuttle vector pBBE22, which includes the virulence determinant BBE22 from lp25 and restores infectivity to readily transformable B. burgdorferi lacking lp25 and lp56, was used to determine the effect of trans expression of vlsE on virulence. Spirochetes lacking lp28-1 were complemented with the plasmid pBBE22:vlsE, containing both BBE22 and vlsE. VlsE protein produced by this construct was expressed and surface accessible in in vitro-cultured B. burgdorferi, as determined by surface proteolysis and immunoblot analysis. Clones lacking lp25 but containing lp28-1 and either pBBE22 or pBBE22:vlsE were reisolated consistently from immunocompetent mice 8 weeks after infection. In contrast, a clone lacking both lp25 and lp28-1 and complemented with pBBE22:vlsE was isolated from only a single tissue of one of six C3H/HeN mice 8 weeks postinfection. These results indicate that either an intact vls antigenic variation locus or another determinant on lp28-1 is required to restore complete infectivity. In addition, an isogenic clone that retained lp28-1 was complemented with the vlsE shuttle plasmid and was examined for vlsE sequence variation and infectivity. Sequence variation was not observed for the shuttle plasmid, indicating that the cis arrangement of vlsE and the vls silent cassettes in lp28-1 facilitate vlsE gene conversion. Lack of vlsE sequence variation on the shuttle plasmid thus did not result in clearance of the trans-complemented strain in immunocompetent mice under the conditions tested.
Do Firm R&D Investments Drive Decisions to Join? On the Value of Standard-Setting Organizations in the Consumer Electronics Industry

Academic research does not yet have a precise understanding of what drives firms' decisions to participate in standard- setting organizations (SSO). We explore the relationship among consortium participation decisions, firm-level R&D investment intensity and production efficiency. We develop theoretical arguments that capture the tradeoffs for joining. They include benefits from steering the future direction of standards, and R&D and knowledge spillovers from other members. Also present are costs from membership fees and risks of free-riding through information disclosures on intellectual property. We develop hypotheses for empirical analysis. We use a logic model to evaluate managerial decisions to join SSOs involving a large data set of publicly-traded consumer electronics firms. The data cover five SSOs in the consumer electronics industry that joined SSOs by 2006. Our results provide evidence that the likelihood of joining an SSO increases with a firm's R&D investment intensity. More efficient firms are more likely to join too.
Amine-reactive surface chemistry of zinc phosphate glasses

Surface chemical studies on zinc phosphate glasses were carried out with an ammonia probe using FTIR and XPS. Low softening point zinc phosphate glasses can be co-extruded with high softening point polymers to form polymer filled blends. NH3 reacts with P-OH groups (Br⊘nsted acid sites) to form bound NH4+ and with the zinc ions (Lewis acid sites) to form coordinately bound NH3. Bulk nitridation reactions, forming various P-N bonds to >100 nm, occur concurrently. The glass surfaces were depleted in Zn compared to the batch compositions. Exposure to ambient water vapor removed Lewis acid bound ammonia; aqueous washing removed both types. Di- and tri-methyl amines also reacted with surface Br⊘nsted and Lewis acid sites. These amine reactions have the potential for binding polymer chains to the glass surface.
Influences of obese (ob/ob) and diabetes (db/db) genotype mutations on lumber vertebral radiological and morphometric indices: Skeletal deformation associated with dysregulated systemic glucometabolism

Both diabetes and obesity syndromes are recognized to promote lumbar vertebral instability, premature osteodegeneration, exacerbate progressive osteoporosis and increase the propensity towards vertebral degeneration, instability and deformation in humans. The influences of single-gene missense mutations, expressing either diabetes (db/db) or obese (ob/ob) metabolic syndromes on vertebral maturation and development in C57BL/KsJ mice were evaluated by radiological and macro-morphometric analysis of the resulting variances in osteodevelopment indices relative to control parameters between 8 and 16 weeks of age (syndrome onset @ 4 weeks), and the influences of low-dose 17-B-estradiol therapy on vertebral growth expression evaluated. Associated with the indicative genotypic obesity and hyper-glycemic/-insulinemic states, both db/db and ob/ob mutants demonstrated a significant (P ≤ 0.05) elongation of total lumbar vertebrae column (VC) regional length, and individual lumbar vertebrae (LV1-5) lengths, relative to control VC and LV parameters. In contrast, LV1-5 width indices were suppressed in db/db and ob/ob mutants relative to control LV growth rates. Between 8 and 16 weeks of age, the suppressed LV1-5 width indices were sustained in both genotype mutant groups relative to control osteomaturation rates. The severity of LV1-5 width osteosuppression correlated with the severe systemic hyperglycemic and hypertriglyceridemic conditions sustained in ob/ob and db/db mutants. Low-dose 17-B-estradiol therapy (E2-HRx: 1.0 ug/ 0.1 ml oil s.c/3.5 days), initiated at 4 weeks of age (i.e., initial onset phase of db/db and ob/ob expressions) re-established control LV 1–5 width indices without influencing VC or LV lengths in db/db groups. These data demonstrate that the abnormal systemic endometabolic states associated with the expression of db/db and ob/ob genomutation syndromes suppress LV 1–5 width osteomaturation rates, but enhanced development related VC and LV length expression, relative to control indices in a progressive manner similar to recognized human metabolic syndrome conditions. Therapeutic E2 modulation of the hyperglycemic component of diabetes-obesity syndrome protected the regional LV from the mutation-induced osteopenic width-growth suppression. These data suggest that these genotype mutation models may prove valuable for the evaluation of therapeutic methodologies suitable for the treatment of human diabetes- or obesity-influenced, LV degeneration-linked human conditions, which demonstrate amelioration from conventional replacement therapies following diagnosis of systemic syndrome-induced LV osteomaturation-associated deformations.
Life and death in the microcirculation: a role for angiotensin II

OBJECTIVE: Angiotensin II (ANGII) plays a critical role in the maintenance of the microcirculation and in the anatomical loss of microvessels (rarefaction) that occurs in low renin forms of hypertension and in animals fed a high-salt diet. Elevations in sodium intake can trigger a series of hemodynamic and hormonal responses culminating in a substantial rarefaction of small arterioles and capillaries in both normal and reduced renal mass hypertensive rats. METHODS: Immunohistochemistry, Northern blot, and reverse transcription-polymerase chain reaction (RT-PCR) analysis of microdissected blood vessels were used to localize ANGII receptors in the microcirculation. Chronic infusion of ANGII and other physiologic and pharmacologic manipulations of the reninangiotensin system in rats was combined with morphologic and mathematical analysis of the network architecture. RESULTS: We have shown that rarefaction of the microcirculation can cause an increase in total peripheral resistance, reduced tissue perfusion, decreased oxygen delivery, and impaired organ function. Although the mechanisms by which this occurs are not well understood, a number of key observations point to a role for the renin-angiotensin system in this effect. First, ANGII infused systemically at subpressor levels, or locally into the skeletal muscle interstitium, can induce significant microvessel growth. Second, localization of ANGII receptor proteins by immunohistochemistry and Western blotting and RNA localization by RT-PCR confirm the presence of AT1 receptors, which are growth-stimulatory, and AT2 receptors, which are growth-inhibitory in the microcirculation. Third, maintenance of ANGII at normal levels during periods of hypertension or high-salt diet completely eliminates rarefaction. CONCLUSIONS: Taken together, these results support the hypothesis that ANGII acting through AT1- and AT2-receptor mechanisms modulate vessel density during high-salt diet and hypertension.
Multiple-Scale Stabilized Finite Elements for the Simulation of Tracer Injections and Waterflood

We present a numerical method for the simulation of miscible and immiscible multiphase ∞ow in porous media, with emphasis on the advection-dominated case. A fractional ∞ow formulation is adopted, resulting in a \pressure" equation and a \saturation" equation. The key idea of the proposed methodology is a multiple scale decomposition of the variable of interest into resolved and unresolved scales. This acknowledges the presence of flne scales which cannot be captured by any grid, but whose in∞uence on the coarse scales is not negligible. The multiscale approach leads to a stabilized flnite element formulation, which prevents global spurious oscillations of the numerical solution without introducing excessive dissipation. The method is further improved by incorporating a novel shock-capturing technique based on a nonlinear dissipation mechanism proportional to the absolute value of the subscales. We believe this approach is entirely new in the context of ∞ow in porous media. Numerical simulations of tracer injection (miscible ∞ow) and water∞ood (immiscible ∞ow) are
Precision engineering: an evolutionary perspective

Precision engineering is a relatively new name for a technology with roots going back over a thousand years; those roots span astronomy, metrology, fundamental standards, manufacturing and money-making (literally). Throughout that history, precision engineers have created links across disparate disciplines to generate innovative responses to society's needs and wants. This review combines historical and technological perspectives to illuminate precision engineering's current character and directions. It first provides us a working definition of precision engineering and then reviews the subject's roots. Examples will be given showing the contributions of the technology to society, while simultaneously showing the creative tension between the technological convergence that spurs new directions and the vertical disintegration that optimizes manufacturing economics.
Natural fiber composites of high-temperature thermoplastic polymers: Effects of coupling agents

Our earlier paper (Jana, S.C.; Prieto, A. J Appl Polym Sci 2002, 86, 2159) on the development of natural fiber composites of high-performance thermoplastic polymers described a new methodology for the manufacturing of composite materials of a high-temperature thermoplastic polymer, poly(phenylene ether) (PPE) and wood flour, a cellulosic natural filler. A thermosetting epoxy, used as a reactive solvent, reduced the processing temperature of PPE/epoxy blends to well below the decomposition temperature of natural fillers. In addition, the epoxy component, upon polymerization, formed coating layers around the filler particles to provide resistance against moisture diffusion and attacks by acids and alkali. This article describes the results of an investigation on two outstanding issues: (1) the influence of cellulosic wood particles and coupling agents on the speed of epoxy curing and reaction-induced phase separation and (2) the effects of coupling agents on the morphology of crosslinked epoxy at the surfaces of natural fillers and mechanical properties of the composites. It was found that wood particles expedited epoxy curing in the composites; the extent of epoxy curing, however, was reduced in the presence of coupling agents. Also, the coupling agents promoted complete coverage of wood flour particles by polymerized epoxy, although the mechanical properties deteriorated over systems without coupling agents. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2168–2173, 2002