cssi/SciSciGPT-SciSciNet huggingface dataset:
Evolution of the chelicera: a dachshund domain is retained in the deutocerebral appendage of Opiliones (Arthropoda, Chelicerata)

The proximo-distal axis of the arthropod leg is patterned by mutually antagonistic developmental expression domains of the genes extradenticle, homothorax, dachshund, and Distal-less. In the deutocerebral appendages (the antennae) of insects and crustaceans, the expression domain of dachshund is frequently either absent or, if present, is not required to pattern medial segments. By contrast, the dachshund domain is entirely absent in the deutocerebral appendages of spiders, the chelicerae. It is unknown whether absence of dachshund expression in the spider chelicera is associated with the two-segmented morphology of this appendage, or whether all chelicerates lack the dachshund domain in their chelicerae. We investigated gene expression in the harvestman Phalangium opilio, which bears the plesiomorphic three-segmented chelicera observed in "primitive" chelicerate orders. Consistent with patterns reported in spiders, in the harvestman chelicera homothorax, extradenticle, and Distal-less have broadly overlapping developmental domains, in contrast with mutually exclusive domains in the legs and pedipalps. However, unlike in spiders, the harvestman chelicera bears a distinct expression domain of dachshund in the proximal segment, the podomere that is putatively lost in derived arachnids. These data suggest that a tripartite proximo-distal domain structure is ancestral to all arthropod appendages, including deutocerebral appendages. As a corollary, these data also provide an intriguing putative genetic mechanism for the diversity of arachnid chelicerae: loss of developmental domains along the proximo-distal axis.
Estrogenic and antiestrogenic properties of resveratrol in mammary tumor models

Trans-3,4',5-trihydroxystilbene (resveratrol), a phytoalexin present in grapes and grape products such as wine, has been identified as a chemopreventive agent. Recent studies performed with MCF-7 human breast cancer cells have demonstrated superestrogenic effects with resveratrol. In contrast, studies performed using estrogen receptor-transfected cell lines have shown that resveratrol acts as a mixed agonist/antagonist. The major objective of this study was to characterize the estrogen-modulatory effects of resveratrol in a variety of in vitro and in vivo mammary models. Thus, the effect of resveratrol alone and in combination with 17beta-estradiol (E2) was assessed with MCF-7, T47D, LY2, and S30 mammary cancer cell lines. With cells transfected with reporter gene systems, the activation of estrogen response element-luciferase was studied, and using Western blot analysis, the expression of E2-responsive progesterone receptor (PR) and presnelin 2 protein was monitored. Furthermore, the effect of resveratrol on formation of preneoplastic lesions (induced by 7,12-dimethylbenz(a)anthracene) and PR expression (with or without E2) was evaluated with mammary glands of BALB/c mice placed in organ culture. Finally, the effect of p.o. administered resveratrol on N-methyl-N-nitrosourea-induced mammary tumors was studied in female Sprague Dawley rats. As a result, in transient transfection studies with MCF-7 cells, resveratrol showed a weak estrogenic response, but when resveratrol was combined with E2 (1 nM), a clear dose-dependent antagonism was observed. Similar mixed estrogenic/antiestrogenic effects were noted with S30 cells, whereas resveratrol functioned as a pure estrogen antagonist with T47D and LY2 cells. Furthermore, in MCF-7 cells, resveratrol induced PR protein expression, but when resveratrol was combined with E2, expression of PR was suppressed. With T47D cells, resveratrol significantly down-regulated steady-state and E2-induced protein levels of PR. With LY2 and S30 cells, resveratrol down-regulated presnelin 2 protein expression. Using the mouse mammary organ culture model, resveratrol induced PR when administered alone, but expression was suppressed in the presence of E2 (1 nM). Furthermore, resveratrol inhibited the formation of estrogen-dependent preneoplastic ductal lesions induced by 7,12-dimethylbenz(a)anthracene in these mammary glands (IC50 = 3.2 microM) and reduced N-methyl-N-nitrosourea-induced mammary tumorigenesis when administered to female Sprague Dawley rats by gavage. Therefore, in the absence of E2, resveratrol exerts mixed estrogen agonist/antagonist activities in some mammary cancer cell lines, but in the presence of E2, resveratrol functions as an antiestrogen. In rodent models, carcinogen-induced preneoplastic lesions and mammary tumors are inhibited. These data suggest that resveratrol may have beneficial effects if used as a chemopreventive agent for breast cancer.
The Oklahoma City Bombing and the Trial of Timothy McVeigh

A bomb carried in a Ryder truck exploded in front of the Murrah Federal Building in Oklahoma City at 9:02 a.m. on April 19, 1995. The bomb claimed 168 innocent lives. That a homegrown, war-decorated American terrorist named Timothy McVeigh drove and parked the Ryder truck in the handicap zone in front of the Murrah Building there is little doubt. In 1997, a jury convicted McVeigh and sentenced him to death. The federal government, after an investigation involving 2,000 agents, also charged two of McVeigh's army buddies, Michael Fortier and Terry Nichols, with advance knowledge of the bombing and participation in the plot. Despite considerable evidence linking various militant white supremacists to the tragedy in Oklahoma City, no other persons faced prosecution for what was - until September 11, 2001 - the worst act of terrorism ever on American soil. The Oklahoma City bombing trials raise questions more interesting than the answers they provide. How, in four years, can an army sergeant and Green Beret aspirant turn so violently against the government he served? If there had been no Waco, would there have been no Oklahoma City? Did McVeigh want to be captured? Why did the government only bring charges against three men in connection with the bombing, when compelling evidence suggests that others played significant roles in the crime? We do not have clear answers to any of these questions - but some possible answers to these and other intriguing questions have come into better focus in the years since the McVeigh and Nichols trials.
A quality evaluation strategy for multi-sourced active pharmaceutical ingredient (API) starting materials

Establishing appropriate impurity specifications for active pharmaceutical ingredient (API) starting materials is an important component of the commercialization and registration of an API. Multiple sources and routes of manufacture of starting materials and the capability of the API synthetic process for tolerating impurities introduced with starting materials must be understood. A strategy for purity method development and use test evaluation of starting materials to aid in establishing quality requirements is described. Phenyl methyl amino propanol (PMAP), a starting material that may be used for fluoxetine hydrochloride and atomoxetine hydrochloride, is used to illustrate the quality evaluation strategy. Knowledge of actual and potential synthetic routes was used to predict potential impurities and guide purity method development. Multiple analytical methods that were semi-orthogonal in the nature of impurity retention (ion-pairing, ion interaction and hydrophilic interaction chromatographic modes) along with use tests were investigated.
Protein kinase C subspecies in rabbit corneal epithelium: increased activity of alpha subspecies during wound healing.

Protein kinase C (PKC) has been implicated in cell proliferation and differentiation. Multiple forms of PKC have been isolated, principally from the brain where PKC is most abundant. In rabbit corneai epithelium, two distinct major peaks of PKC activity were resolved by hydroxyapatite column chromatography. Peak 2, with 65% of the total PKC activity, corresponds to $aL-PKC, based on its mobility in the column and Western blot analysis using specific monoclonal antibodies. Peak 1 did not react with either polyclonal or monoclonal antibodies to PKC $aL-, β-, and γ-isoforms suggesting the presence of isoforms specific to the corneai epithelium, or of another member of the PKC family.To investigate possible changes in the amounts of the various PKC subspecies during wound healing, the enzyme activities of the isolated subspecies were assayed 2, 5, and 7 days after corneai de-epithelialization. Two days after wounding, by which time the migratory limbal epithelium had covered the denuded area, total PKC activi...
ROLE OF ABIOTIC FACTORS IN GOVERNING SUSCEPTIBILITY TO INVASION: A TEST WITH ARGENTINE ANTS

Hypotheses concerning community-level vulnerability to invasion often emphasize biotic interactions but fail to consider fine-scale variation in the physical environment. In this study, the interplay between interspecific competition and abiotic factors is examined with respect to whether scrub habitats in southern California become invaded by the Argentine ant (Linepithema humile). Argentine ants penetrate further into and attain higher abundances in mesic scrub fragments than they do in xeric scrub fragments. Probably as a result, native ant richness is lower in small (<30 ha), mesic fragments than in either small, xeric fragments or in small plots in unfragmented areas. Compared to six species of native ants, Argentine ants ranked lowest in their ability to tolerate high temperatures in the laboratory with 100% of field-collected workers dying after 60 min of exposure to temperatures ≥46°C. Field data corroborate these results; mean temperatures at which colonies of Argentine ants attained maximum abundance at baits (34.0°C) and abandoned baits (41.6°C) were both lower than for the native ant Dorymyrmex insanus. Laboratory studies further revealed that low levels of soil moisture depress mean worker survival in experimental colonies of Argentine ants. In a factorial laboratory experiment that varied both physical conditions and interspecific competition, Argentine ants exhibited greater worker activity and survival under warm, moist conditions than under hot, dry conditions, whereas the presence of a competitor, Forelius mccooki, had no significant effect. Experimental colonies of F. mccooki, in contrast, were more active under hot, dry conditions than under warm, moist conditions and exhibited reduced activity in the presence of L. humile irrespective of physical conditions. Taken together, these experimental data demonstrate how the abiotic environment impinges on both colony-level activity and colony growth in the Argentine ant and provide a general explanation for the patterns observed at the community level. A key consequence of the condition-specific nature of the competitive asymmetry between Argentine ants and native ants is that community-level vulnerability to invasion appears to depend primarily on the suitability of the physical environment from the perspective of L. humile.
Wave Propagation in Poroelastic Media Saturated by Two Fluids

A theory of wave propagation in isotropic poroelastic media saturated by two immiscible Newtonian fluids is presented. The macroscopic constitutive relations, and mass and momentum balance equations are obtained by volume averaging the microscale balance and constitutive equations and assuming small deformations. Momentum transfer terms are expressed in terms of intrinsic and relative permeabilities assuming the validity of Darcy's law. The coefficients of macroscopic constitutive relations are expressed in terms of measurable quantities in a novel way. The theory demonstrates the existence of three compressional and one rotational wave. The third compressional wave is associated with the pressure difference between the fluid phase and dependent on the slope of the capillary pressure-saturation relation.
Midazolam, as a co‐induction agent, has propofol sparing effects but also decreases systolic blood pressure in healthy dogs

Abstract Objective To evaluate the effects of the co-administration of midazolam on the dose requirement for propofol anesthesia induction, heart rate (HR), systolic arterial pressure (SAP) and the incidence of excitement. Study design Prospective, randomized, controlled and blinded clinical study, with owner consent. Animals Seventeen healthy, client owned dogs weighing 28 ± 18 kg and aged 4.9 ± 3.9 years old. Methods Dogs were sedated with acepromazine 0.025 mg kg −1 and morphine 0.25 mg kg −1 intramuscularly (IM), 30 minutes prior to induction of anesthesia. Patients were randomly allocated to receive midazolam (MP; 0.2 mg kg −1 ) or sterile normal saline (CP; 0.04 mL kg −1 ) intravenously (IV) over 15 seconds. Propofol was administered IV immediately following test drug and delivered at 3 mg kg −1 minute −1 until intubation was possible. Scoring of pre-induction sedation, ease of intubation, quality of induction, and presence or absence of excitement following co-induction agent, was recorded. HR, SAP and respiratory rate (f R ) were obtained immediately prior to, immediately following, and 5 minutes following induction of anesthesia. Results There were no significant differences between groups with regard to weight, age, gender, or sedation. Excitement occurred in 5/9 dogs following midazolam administration, with none noted in the control group. The dose of propofol administered to the midazolam group was significantly less than in the control group. Differences in HR were not significant between groups. SAP was significantly lower in the midazolam group compared with baseline values 5 minutes after its administration. However, values remained clinically acceptable. Conclusions and clinical relevance The co-administration of midazolam with propofol decreased the total dose of propofol needed for induction of anesthesia in sedated healthy dogs, caused some excitement and a clinically unimportant decrease in SAP.
Ethanol neurotoxicity in culture: Selective loss of cholinergic neurons

Studies from our laboratory have shown that in ovo exposure of chick embryos to ethanol decreases neuronal survival in culture, and shifts neurotransmitter phenotypic from cholinergic to catecholaminergic and GABAergic. In this study we attempted to determine if the shift from cholinergic expression is a result of selective loss of cholinergic neurons. Neuron-enriched primary cultures were prepared from 3-day-old whole chick embryos. Cells proliferating during the first 3 days in culture were labeled with BrdU, and one half of the cultures were exposed to 50 mM ethanol during the same time period. Selective survival in vitro of the cholinergic, catecholaminergic. GABAergic, glutamatergic, and somatostatinergic phenotypes was determined by counting cells double-stained for BrdU and either ChAT, TH, GAD, Glu, or SRIF. We found that ethanol exposure resulted in a significant reduction in neuronal survival within the cholinergic phenotype, both in the total number of ChAT+ cells and in the subpopulation born between 0-3 DIV. In addition, survival of glutamatergic neurons "born" between 0-3 days in vitro was significantly enhanced, while survival in catecholaminergic, GABAergic, and somatostatinergic phenotypes was also enhanced slightly. These results corroborate our earlier biochemical findings and suggest that the differential cholinotoxic effect of ethanol is due, at least in part, to enhancement of cell-death of cholinergic neuroblasts. This does not preclude the possibility that multipotent neuroblasts are also influenced to express alternative phenotypes, and analyses of these data, in fact, support this notion as well.
Constrained estimation of percussive sound excitations

Source-filter models for sound resynthesis are useful in applications including compression of audio data and restoration of noisy recordings. Driven by actual recordings of sounding objects, resynthesis methods require system identification and excitation source estimation. Such methods may be entirely data-driven, but they may also incorporate a priori knowledge of systems or excitations. This paper proposes a method of estimating the excitation of percussively struck resonant objects from sound recordings, constraining the excitation to be time-limited. The constraint serves to use prior knowledge of the short duration of the excitations of percussive sounds, improving estimation when compared to other methods of unconstrained estimation and inverse filtering. Evaluated examples and simulations demonstrate the proposed method's robustness to noise and applicability to the analysis and resynthesis of acoustic recordings.
Delivery and verification of intensity‐modulated x‐ray beams in radiotherapy

This thesis deals with the implementation of intensity-modulated radiation therapy into the clinic and a method of quality assurance which can be used on each intensity-modulated beam prior to treatment. The first component of the thesis was to write a step-and-shoot leaf sequence algorithm to control the multileaf collimator(MLC) fitted to our Clinac 2300 C/D linear accelerator. Our algorithm takes into account the MLC transmission, MLC penumbra, and change in scatter conditions with field size and is also slightly more efficient than other published step-and-shoot type algorithms. The second (and major) component of the thesis was to investigate the use of a portal imaging device for dosimetric verification purposes. We show that an electronic portal imaging device of the scanning liquid ionization chamber type yields images which, once calibrated from a previously determined calibration curve, provide highly precise planar maps of the incident dose rate. For verification of an intensity-modulated x-ray beam delivered in the segmented approach with a MLC, a portal image is acquired for each subfield of the leaf sequence. Subsequent to their calibration, the images are multiplied by their respective associated monitor unit settings, and summed to produce a planar dose distribution at the measurement depth in phantom. The excellent agreement of our portal imager measurements with calculations of our treatment planning system and data from a one-dimensional beam profiler attests to the usefulness of this method for the planar verification of intensity-modulated fields produced in the segmented approach on a computerized linear accelerator equipped with a multileaf collimator.
Local forced convective heat transfer from protruding and flush-mounted two-dimensional discrete heat sources

Abstract Experiments are undertaken to measure the local forced convective heat transfer characteristics of an array of two-dimensional discrete heat sources. Air flow rates yielding effective channel Reynolds numbers in the range from 1000 to 10000 are employed. Flush-mounted and protruding heater configurations are investigated in the study. Two different channel wall spacings independent of the heat source protrusion are also studied. Local temperature measurements are made along the uniformly heated surface parallel to the flow direction. The results of the experiments show that protruding heat sources yield higher heat transfer than flush-mounted heat sources at the same channel Reynolds number. The interruption of the thermal boundary layer in the adiabatic sections between the heaters results in heat transfer enhancement. Heat source protrusion yields significantly higher heat transfer rates for the second and subsequent heater for channal Reynolds numbers above 2000. This is explained in terms of a separated flow and vena contracta effect, with eventual downstream transition to turbulent flow, and is borne out by flow visualization experiments. The local heat transfer measurements reveal significant variation in wall temperature across the heater faces, which is strongly affected by the flow structure. Average heat transfer coefficients calculated by spatially integrating the local measurements are correlated and presented in terms of Reynolds number and the dimensionless geometric parameters studied.
Tracking Changes in Political Science Dissertations at Penn State: 1953–2010

Bibliographies from 40 doctoral dissertations in political science from Penn State University were analyzed to detect any changes that may have occurred in the types and subject classifications of cited sources over time. The oldest dissertations in this sample reflected a research methodology more akin to history, while the newest reflected a methodology more in line with the social sciences. Results were then compared and contrasted with those of prior studies. The exercise of local citation analysis can connect librarians more deeply to a discipline as it is practiced at their institution, benefitting their own understanding and the services they provide.
Critical Values of Derivatives of Twisted Elliptic $L$-Functions

Let L(E/ℚ, s) be the L-function of an elliptic curve E defined over the rational field ℚ. We examine special values of the derivatives L'(E, 1, χ) of twists by Dirichlet characters of L(E/ℚ, s) when L(E, 1, χ) = 0.
Cubic rare-earth compounds: variants of the three-state Potts model

In appropriate cubic fields rare-earth ions have sixfold degenerate ground states. When the angular momentum of the rare earth is large, the six levels are characterized by states that are directed along the cube edges. Within these states the angular momentum operators ${J}_{x}$, ${J}_{y}$, and ${J}_{z}$ have particularly simple matrix representations. The projection of an isotropic pair coupling between the rare earths onto these sixfold degenerate states leads to an interaction Hamiltonian $\mathcal{H}=\ensuremath{-}\mathcal{I}\ensuremath{\Sigma}{〈\mathrm{ij}〉}^{}{\ensuremath{\sigma}}_{i}{\ensuremath{\sigma}}_{j}{\ensuremath{\delta}}_{{l}_{i}{l}_{j}}$, where $\ensuremath{\sigma}$ takes on the values \ifmmode\pm\else\textpm\fi{} 1 and $l$ the values $x$, $y$, and $z$. This interaction is a variant of the three-state Potts model. We add magnetic and quadrupolar anisotropy field terms to the Hamiltonian and determine the symmetry properties of the phase diagram associated with this model. For nonzero quadrupolar anisotropy fields, the model is shown to have the thermodynamic behavior of an Ising model. However, for zero fields we find a new symmetry appears and in the mean-field approximation the model has tricritical-like exponents. This simple model is able to account for the large specific-heat critical exponent ${\ensuremath{\alpha}}^{\ensuremath{'}}=\frac{1}{2}$ which has been observed for holmium antimonide in zero external fields. To the extent that the mean-field approximation is an accurate guide, we predict there are many cubic rare-earth compounds which exhibit tricritical-like behavior in zero field. In addition we find that for pure quadrupole coupling between rare earths in the sixfold degenerate states, the interaction Hamiltonian is exactly the three-state Potts model. In the mean-field approximation this system has a first-order phase transition. However, a small quadrupolar anisotropy field is sufficient to drive the system to a wing critical point. The specific heat has a critical exponent of $\ensuremath{\alpha}=\frac{2}{3} or 1$ depending on the path taken to approach this critical point.
X-ray Telescope Module for the LAMAR Space Shuttle Experiment

The first of eight X-ray telescopes is under construction for the LAMAR experiment. Each consists of two orthogonal sets of nested confocal one-dimensional parabolic plates of gold-coated float glass, selected for flatness from commercial stock. Each is initially bent to a cylinder by bonding a thin, highly curved titanium sheet to its inactive surface. The final parabolic figure is produced by an automated system which includes seven diode arrays that detect a visible-light line image. Eight precise motorized linear translators operating under the control of a computer, tune the plate to the optimum figure. The plate is then fixed in position by epoxy bonds. The precision of the system is several arcsec, but the intrinsic flatness of the glass is expected to limit the half-power diameter (HPD) of the telescope to about 25 arcsec.
Semantic data integration in hierarchical domains

A major challenge in building the Semantic Web is resolving differences among heterogeneous databases. This article describes one approach for handling semantic data integration problems in hierarchical domains. It also describes a declarative approach for specifying pairwise mappings between a centrally maintained ontology and each local data repository maintained by an autonomous agency. In this context, it outlines a method for specifying the mappings' semantics and encoding them to resolve heterogeneities. It focuses on XML-based applications in which entities in the centrally maintained ontology are hierarchically related to those in the local data repositories.
Anole classification: a response to Poe

A recent correspondence (Poe 2013; hereafter referred to simply as ‘Poe,’ ‘he,’ or ‘his’) criticized our monographic revision of anole classification (Nicholson et al. 2012; hereafter referred to as ‘our’). In tone and content, Poe expresses his distress with the idea that his preferred concept of a single, large genus, containing all living members of the family Dactyloidae, might be divided into eight smaller genera. We acknowledge that science benefits from vigorous, intellectual debate, but would have preferred his commentary to be more constructive, objective, and scientifically accurate. We therefore present this rebuttal to explain how Poe erred in characterizing our work, and missed the opportunity to present an alternative comprehensive taxonomy to replace the one against which he argues so strenuously. In this contribution we explain, and correct, Poe’s errors and misrepresentations, and argue that our taxonomy is likely to be adopted because it 1) eliminates the obvious problem that will arise if the family Dactyloidae contains only a single large genus (i.e., that a single genus obscures the evolution and diversity within the group and misrepresents or cloaks it), 2) conforms with the long historical trend of dissecting large, cumbersome groups into smaller sub-units, 3) is consistent with all recent phylogenetic studies for anoles in membership within clades we recognize as genera, and 4) aids in associating these lizards with the ancient land masses that shaped their history.
Neuroheptapeptide influence on attention and memory in man.

Abstract Twenty normal, male volunteers were administered a subcutaneous injection of either ACTH/MSH 4–10 or diluent and two weeks later received the alternate injection inca complete crossover, double-blind design with order balanced. Subjects were given a battery of psychological tests including a continuous performance task (CPT), following each injection. Visual evoked responses were recorded during the CPT. Resting, eyes-closed EEGs were also obtained. ACTH/MSH 4–10 improved attention and in so doing improved visual-motor learning and visual, but not verbal, memory. EEG data were consistent with activation of the diffuse thalamic projection system.
The phase structure of QED3 with fermion self-coupling

Abstract The ground state phase structure of QED3 with four-Fermi interactions and N flavors is determined via the 1 N Schwinger-Dyson equations. We consider two different four-Fermi couplings G and H, which can induce the breakdown of Z2, and parity symmetries, respectively. A critical surface in coupling constant space is determined, which delineates regions where dynamical breakdown of parity invariance as well as the discrete Z2 symmetry occurs from those in which these symmetries are preserved. We obtain a critical value of N, Nc = Nc(H), below which chiral symmetry breaking develops even for G = 0. As H approaches its critical line, new dynamical degrees of freedom arise which disfavor Z2 breakdown, thus lowering the value of Nc.
Motion segmentation using singular value decomposition

This paper presents a method for the segmentation of multiple motions in a scene using the singular value decomposition of a feature track matrix. It is shown that motions can be separated using the right singular vectors associated with the nonzero singular values. This is based on the relationship between the right singular vectors and the principal components of the covariance matrix of the tracks. Furthermore, under general assumptions, the number of numerically nonzero singular values can be used to determine the number of motions. This can be used to derive a relationship between a good segmentation, the number of nonzero singular values in the input and the sum of the number of nonzero singular values in the segments. The approach is demonstrated on real and synthetic examples and a study of the robustness of the method is given. The paper ends with a critical analysis of the approach.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Mesoscale Analysis of Shear Bands in High Strain Rate Deformations of Tungsten/Nickel-Iron Composites

ABSTRACT We analyze the initiation and propagation of adiabatic shear bands in a tungsten heavy alloy by modeling each constituent as a heat-conducting, microporous, isotropic, elastothermoviscoplastic material. The two constituents are assumed to be perfectly bonded to each other so that the temperature, heat flux, displacements, and surface tractions are continuous across an interface between a tungsten particulate and the nickel-iron matrix. Three different modes of deformation, namely plane strain tension/compression, plane strain shear, and axisymmetric tension/compression are analyzed. No other defects are introduced. It is found that contours of the rate of temperature rise and/or velocity and/or the specific energy dissipation rate rather than those of effective plastic strain delineate the shear banded regions. For the same volume fraction of particulates smaller diameter particulates enhance the formation of adiabatic shear bands. The time of initiation of an adiabatic shear band also depends up...
Measurement and simulation of jet mass caused by a high-aspect ratio hole perturbation

Inertial confinement fusion (ICF) capsule performance can be negatively impacted by the presence of hydrodynamic instabilities. To perform a gas fill on an ICF capsule current plans involve drilling a small hole and inserting a fill tube to inject the gas mixture into the capsule. This introduces a perturbation on the capsule, which can seed hydrodynamic instabilities. The small hole can cause jetting of the shell material into the gas, which might adversely affect the capsule performance. We have performed simulations and experiments to study the hydrodynamic evolution of jets from high-aspect ratio holes, such as the fill tube hole. Although simulations using cold materials over predict the amount of mass in the jet, when a reasonable amount of preheat (< 1 eV) is introduced, the simulations are in better agreement with the experiment.
Effects of buoyancy on steady hydrogen gas-jet diffusion flames

Laminar gas-jet diffusion flames of a nonsooting, fast reacting fuel were investigated at atmospheric pressure in microgravity and at different pressures in normal gravity. These weakly luminous flames were visualized and quantified using the rainbow schlieren deflectometry. The results show that the overall features of the microgravity flame are replicated in normal gravity experiments at sub-atmospheric pressures. The flame width in microgravity correlated with that in normal gravity, when the normalized Froude number at the burner exit was used as a parameter. Normal gravity experiments at low pressures produced nonbuoyant flames that remained parallel to the burner tube regardless of the tube's orientation with respect to the gravitational vector.
On the fiftieth anniversary of the Schaechter, Maaløe, Kjeldgaard experiments: implications for cell-cycle and cell-growth control

The Schaechter-Maaloe-Kjeldgaard papers, which have their 50(th) anniversary this year, have major implications for understanding the cell cycle, control of cell growth, control of cell size, metabolic control, the basic bacterial growth curve, and myriad other bacterial and eukaryotic growth phenomena. These ideas have broad applications that should be considered in current studies of the cell cycle. In particular, the emphasis on steady-state growth conditions, and clear and sharp changes in growth conditions were fundamental to their experiments and have been codified in the principles of the Copenhagen School of Microbiology.
Self-resolution of Epstein-Barr virus–associated B-cell lymphoma in a patient with dermatomyositis following withdrawal of mycophenolate mofetil and methotrexate

Abstract Self-resolving Epstein-Barr virus (EBV)–associated lymphomas have become more common with the use of immunosuppressive agents in both transplant patients and patients with connective tissue disorders. Immunosuppressive agents are often used for control of dermatomyositis, but their use has not been linked to subsequent malignancy. We present a 46-year-old woman with dermatomyositis, who developed an EBV-associated B-cell lymphoma of the brain while on oral methotrexate, mycophenolate mofetil and low-dose prednisone. The patient's lymphoma gradually resolved "spontaneously" upon discontinuation of the methotrexate and mycophenolate mofetil. The potential for EBV-associated B-cell lymphoma to self-resolve should be recognized by the clinician in order to prevent unnecessary and potentially toxic treatments including radiation therapy or multi-drug chemotherapy.
Polymer/Single-Walled Carbon Nanotube Films Assembled via Donor−Acceptor Interactions and Their Use as Scaffolds for Silica Deposition

A method of stepwise assembling thin polymer/single-walled carbon nanotube (SWCNT) films using donor−acceptor interactions is demonstrated. When the affinity that amine groups have for nanotubes were utilized, films were formed by the sequential adsorption of polyethylenimine and polyallylamine followed by SWCNTs onto silicon substrates. In an effort to expand this methodology to more thermally and oxidatively stable polymer systems, the ability of the basic nitrogen of the pyridine ring to adsorb SWCNTs was also investigated. These studies demonstrated that the nonsterically hindered, para-substituted pyridine in poly(4-vinylpyridine) (P4VP) also has an affinity for SWCNTs, thus enabling the stepwise formation of P4VP/SWCNT films. Microscopy of the films revealed that they were formed of single tubes and small bundles and that film coverage and thickness were uniform. The ability to use these films as scaffolds for the synthesis of novel hybrid structures is demonstrated by modifying the P4VP films using...
Initial recovery patterns may predict which maintenance therapies for depression will keep older adults well

Abstract Background: Although active maintenance treatments appear superior to placebo in preventing depression recurrence in older adults, few data are available to guide maintenance modality selection to maximize the probability of continued wellness for a given patient. Patients’ temporal patterns of acute treatment response may predict who requires which maintenance therapy to remain well. Methods: Depression levels were observed over 16 weeks of combined nortriptyline (NT) and interpersonal psychotherapy (IPT) in 140 persons aged ≥60 years with recurrent major depression. Subjects were empirically classified into four groups: rapid, sustained responders; delayed, sustained responders; mixed responders without sustained improvement; prolonged nonresponders. Groups were compared on subsequent recovery rates and on time to depression recurrence after randomization to 3 years of combined maintenance therapy (monthly IPT with NT), monotherapy (either IPT or NT alone), or medication clinic with placebo. Pretreatment psychosocial and clinical variables were controlled. Results: Initial response profile predicted ultimate recovery rates, as well as who remained well, given the maintenance treatment received. Rapid initial responders showed lower recurrence risk with either combined or monotherapy, relative to placebo. Specific types of monotherapy appeared equally effective in rapid responders. In initially mixed responders, only combined therapy was superior to placebo. It was marginally superior to monotherapy. For delayed responders, combined therapy was superior to placebo; monotherapy did not differ from the other maintenance conditions. Prolonged nonresponders did not benefit from maintenance treatment. Limitations: Subjects had only recurrent, unipolar depression. Initial response profile groups were established empirically and require replication. Sample sizes in initial response profile by maintenance treatment cells were small. Conclusion: The ability to match patients to maintenance treatments more likely to prevent recurrence may be enhanced by considering the temporal profile of initial response to acute treatment.
Predicting Scientific Understanding of Prospective Elementary Teachers: Role of Gender, Education Level, Courses in Science, and Attitudes Toward Science and Mathematics

A multiple regression analysis of the relationship between prospective teachers' scientific understanding and Gender, Education Level (High School, College), Courses in Science (Biology, Chemistry, Physics, Earth Science, Astronomy, and Agriculture), Attitude Towards Science, and Attitude Towards Mathematics is reported. Undergraduate elementary science students (N = 176) in an urban doctoral-level university in the United States participated in this study. The results of this study showed Gender, completion of courses in High School Chemistry and Physics, College Chemistry and Physics, and Attitudes Toward Mathematics and Science significantly correlated with scientific understanding. Based on a regression model, Gender, and College Chemistry and Physics experiences added significant predictive accuracy to scientific understanding among prospective elementary teachers compared to the other variables.
Exercise-Induced ST Segment Alternane

We report a rare electrocardiographic finding occurring in previously undescribed circumstances in which a 61-year-old man undergoing exercise testing developed striking ST segment elevation on the ECG characterized by electrical alternans of the ST segments. The significance of electrical alternans is briefly discussed in the light of this event.
The Charrette project: Manipulating text and image in an electronic archive of a medieval manuscript tradition

This paper concerns the Charrette Project, a multimedia electronic archive of a medieval manuscript tradition. In this paper, we argue that the computer's strengths in manipulating complex and varied resources should be an important organizing principle in the conception and construction of electronic text projects. Specifically, we describe the elements of the Charrette archive, its architecture, and its potential for scholarly research and pedagogical applications.
The word-retrieval deficit hypothesis and developmental dyslexia

Abstract An overview of a systematic research program on the relationship between subprocesses of naming and reading development is provided. In Phase 1 a battery of naming and reading tasks was selected based on a theoretical model drawn from the cognitive, psycholinguistic, and neuropsychological research traditions. In Phase 2 the battery was cross-validated in a cross-sectional study. In Phase 3 a 5-year longitudinal study examined the predictive relationships between subprocesses of naming and reading development. In Phase 4 a pilot treatment study for dyslexics was begun to increase their breadth and depth of word knowledge and to improve their ability to retrieve words accurately and rapidly. Evidence is reported that dyslexic children have a specific deficit in rapid retrieval of names. It is speculated that speed of naming problems may be related to problems in rate of processing in other domains; a deficit in a specific timing mechanism is considered.
A new approach for enhancing differential selectivity of drugs to cancer cells.

The degree to which anticancer agents selectively target cancer cells is a key determinant in successful therapeutic outcomes. Inhibitors of the Hsp90 molecular chaperone represent an important new class of anticancer agents. We propose here a novel mechanism by which physiochemical properties of Hsp90 inhibitors can be optimized to increase selectivity towards cancer cells. The basis for this approach relies on differential intracellular pH gradients that have been shown to exist between normal and transformed cells. Five Hsp90 inhibitors containing basic or neutral properties were evaluated in antiproliferation assays using cells with variable lysosomal pH. Inhibitors with basic functionalities had reduced activity in cells with normal (low) lysosomal pH but showed significantly greater activity in cells with abnormally elevated lysosomal pH (similar to what has been recorded in many types of cancer cells). Conversely, such selectivity enhancement was not observed for neutral inhibitors. The mechanistic...
Divinyl Sulfone as a Postdigestion Modifier for Enhancing the a1 Ion in MS/MS and Postsource Decay: Potential Applications in Proteomics

Divinyl sulfone reacts at pH 8−9 with the α-amino groups of N-terminal residues, proline, the e-amino groups of lysine, and the histidine side chains of peptides. This reaction leads to great enhancement of the abundance of the normally weak or missing “a1” fragment ion in MS/MS analysis defining the N-terminal residue of a peptide in a digest. This provides “one-step Edman-like” information that, together with a fairly accurately determined mass, often enables one to correctly identify a protein or family of proteins. The applicability of this procedure in proteomics was demonstrated with several peptides and tryptic digests of protein mixtures by LC−MS/MS experiments using a QTOF and MALDI-PSD analyses. Advantages of this approach are its simple chemistry, retention of charge multiplicity, and possibly, shortening of database search time. Used with other MS/MS data, it provides higher confidence in the scores and identification of a protein found in peptide mass fingerprinting. Moreover, this approach h...
Comparison of Cervical Spine Fixation Devices

Injury to the cervical spine can be debilitating injury. Fracture the Dens of the C1-C2 motion segment can lead to gross instability of the cervical spine and neurological deficit. It is important to achieve stability operatively. Posterior fusion is considered by some to be a relatively safe operation compared to other procedures. Any spinal surgery which relies on boney stabilization post-operatively must provide a sufficiently small amount of movement initially to allow bone consolidation and healing.Copyright © 2009 by ASME
Effects of acetaminophen on cadmium metabolism in mice.

Acetaminophen (ACM) administration to mice of the (C57BL6 × DBA2)F1 strain produced a typical hepatic centrilobular necrosis similar to that observed in rodents and humans. To determine the effects of this drug-induced necrosis on cadmium (Cd) metabolism, mice were given a sublethal dose of CdCl2 · 2.5 H2O containing 109CdCl2 and maintained for a period of time sufficient for Cd-metallothionein (Cd-MT) to be synthesized and distributed. Subsequent administration of ACM ip or po evoked a marked redistribution of Cd from livers to kidneys of mice, and increased the amount of Cd excreted in urine and feces. There were only minimal or no effects on Cd concentrations in other organs assessed. The effect of ACM on Cd redistribution was antagonized by administration of cysteine, a glutathione precursor, and was enhanced by pretreatment with phenobarbital, a potent inducer of the cytochrome P-450 mixed-function oxidase system. Pretreatment of mice with ACM 6 or 24 hr prior to Cd administration caused aberrations of the normal Cd distribution pattern, but no effect was noted when Cd administration was delayed for 48 hr after ACM injection, indicating recovery of the mechanisms of Cd-MT synthesis and sequestration. Sephadex G-75 gel filtration chromatography of serum from ACM-treated mice showed that most of the Cd was associated with high-molecular-weight proteins, and only a minor portion was present as Cd-MT. Cd excreted in urine was predominantly in a lowmolecular-weight form, but there was evidence of two minor components of higher molecular weight, neither of which eluted as Cd-MT. Cd excreted in feces was insoluble following homogenization in 0.25 m sucrose solution. Cd in livers and kidneys of ACM-treated mice eluted as Cd-MT. It was concluded that persons who have a moderately high Cd burden may be at risk of Cd nephrotoxicity if they incur hepatic necrosis subsequent to ACM abuse.
Tree Structure for Contractible Regions in R 3

For contractible regions ?in ?3 with generic smooth boundary, we determine the global structure of the Blum medial axis M. We give an algorithm for decomposing M into "irreducible components" which are attached to each other along "fin curves". The attaching cannot be described by a tree structure as in the 2D case. However, a simplified but topologically equivalent medial structure ? M with the same irreducible components can be described by a two level tree structure. The top level describes the simplified form of the attaching, and the second level tree structure for each irreducible component specifies how to construct the component by attaching smooth medial sheets to the network of Y-branch curves. The conditions for these structures are complete in the sense that any region whose Blum medial axis satisfies the conditions is contractible.
Modeling open boundaries in dissipative MHD simulation

The truncation of large physical domains to concentrate computational resources is necessary or desirable in simulating many natural and man-made plasma phenomena. Three open boundary condition (BC) methods for such domain truncation of dissipative magnetohydrodynamics (MHD) problems are described and compared here. A novel technique, lacuna-based open boundary conditions (LOBC), is presented for applying open BC to dissipative MHD and other hyperbolic and mixed hyperbolic-parabolic systems of partial differential equations. LOBC, based on manipulating Calderon-type near-boundary sources, essentially damp hyperbolic effects in an exterior region attached to the simulation domain and apply BC appropriate for the remaining parabolic effects (if present) at the exterior region boundary. Another technique, approximate Riemann BC (ARBC), is adapted from finite volume and discontinuous Galerkin methods. In ARBC, the value of incoming flux is specified using a local, characteristic-based method. A third commonly-used open BC, zero-normal derivative BC (ZND BC), is presented for comparison. These open BC are tested in several gas dynamics and dissipative MHD problems. LOBC are found to give stable, low-reflection solutions even in the presence of strong parabolic behavior, while ARBC are stable only when hyperbolic behavior is dominant. Pros and cons of the techniques are discussed and put into context within the body of open BC research to date.