cssi/SciSciGPT-SciSciNet huggingface dataset:
Adsorption and self-assembly of octyl hydroxamic acid at a fluorite surface as revealed by sum-frequency vibrational spectroscopy

In the study described here, the surface structure of a self-assembly octyl hydroxamic acid at a calcium fluoride (CaF(2)) surface is evaluated using sum-frequency vibrational spectroscopy (SFVS). Of particular significance are the results that show octyl hydroxamic acid adsorbs at the fluorite surface from octanol solution and has more ordering and molecular conformation than the octyl hydroxamic acid adsorbed from solution. At the fluorite/0.1 M octyl hydroxamic acid octanol solution interface a bilayer-like structure consisting of an octyl hydroxamic acid layer in contact with fluorite and a tilted alcohol layer was observed by SFVS. The alcohol molecules are oriented with respect to the hydroxamic acid monolayer with the OH groups directed towards the bulk alcohol phase and the terminal CH(3) group oriented to face the alkyl chains of the hydroxamic acid monolayer.
THE PUBLIC HEALTH IMPACT OF IRRITANT CONTACT DERMATITIS

The public health impact of a disease can be measured using statistical, clinical, and economic measures. Three factors point out the importance of irritant contact dermatitis (ICD) as a disease having a public health impact→1) ICD is common; 2) ICD often has a poor prognosis; and 3) ICD results in a noteworthy economic impact for society and for an individual as it affects vocational and avocational activities. It is also a disease amenable to public health interventions.
The anion in salt taste: a possible role for paracellular pathways.

Abstract It is well established from psychophysical and electrophysiological measurements that both Na and Cl contribute to the taste response to NaCl. The contribution of Na to the NaCl response can be studied using amiloride, a drug that inhibits Na transport in taste and other epithelial cells. The pathways involved in response to Cl are less well understood. We undertook a series of experiments in the rat to determine whether tonic chorda tympani responss to NaCl are inhibited by specific inhibitors of anion transport. Whole nerve responses to NaCl were unchanged by bathing the tongue in SITS, DIDS, bumetanide, furosemide, 9-anthracene car☐ylic acid, or an antibody that blocks Cl conductance pathways in many epithelia. Thus, Cl co-transporters, exchangers, and channels (at least in the apical membrane of taste cells) are probably not involved in NaCl taste responses. When other anions (acetate, isethionate, methane sulfonate, gluconate, tartrate) which, are generally impermeant in other Cl-selective pathways, were substituted for Cl, the dose-response curves for the chorda tympani response were shifted toward higher concentrations than the response to NaCl, but achieved the same maximum value at sufficiently high concentrations (1.0 M Na). For all the organic Na salts, the amiloride-insensitive portion of the response was substantially less than for NaCl. Experiments with Na acetate at different pHs showed that intracellular acidification is not responsible for the differences between NaCl and organic salts of Na. One possibility which remains is that apical stimulation with these other Na salts results in a taste cell membrane potential that is hyperpolarized with respect to the membrane potential in NaCl. The hyperpolarization could arise as a consequences of lower permeability to organic anions of the tight junctions between taste cells. Such a hyperpolarization would explain the shift in dose-response curves, the altered amiloride sensitivity, and might also explain how a salt stimulus could affect taste cells specific for other, non-salt stimuli.
Mercury-Based Cuprate High-Transition Temperature Grain-Boundary Junctions and SQUIDs Operating Above 110 Kelvin.

The superconducting transport characteristics of HgBa2 CaCu2O6+δ (Hg-1212) films and grain-boundary junctions grown on (100)-oriented SrTiO3 bicrystal substrates have been investigated. The films exhibit a zero-resistance temperature of ∼120 kelvin and sustain large critical current densities, with values as high as 106 amperes per square centimeter at around 100 kelvin. On the other hand, the grain boundaries behave as weak links, with substantially lower critical currents, as is observed for other cuprate superconductors. A reduction of three orders of magnitude in critical current was observed for transport across a 36.8° grain boundary. The current-voltage characteristics of bridges across such a grain boundary show weak-link behavior qualitatively resembling that of a resistively shunted junction. Single-level direct-current superconducting quantum interference devices (SQUIDs) have been fabricated with such bicrystal junctions. These SQUIDs show clear periodic voltage modulations when subjected to applied magnetic fields. The SQUIDs operate at temperatures as high as 111.8 kelvin, which makes them attractive for operation in portable sensors and devices that utilize nonconventional cooling methods.
Comparison of total and prostatic fraction serum acid phosphatase levels in patients with differentiated and undifferentiated prostatic carcinoma.

Simultaneously determined total serum prostatic acid phosphatase (TSPAP) and tartrate-labile prostatic phosphatase (PAP) values were determined in 326 randomly selected patients, with histologically verified BPH (141 cases) or carcinoma of the prostate (185 cases). Unexplained elevations in TSPAP were noted in 7% of BPH cases. A 2.7% incidence of similar unexplained elevated PAP values was observed. However, in prostatic carcinoma cases, TSPAP was increased above normal range in 63.8% while PAP values were elevated in only 41.1%. When prostatic carcinoma cases are subdivided according to the clinical stage of the disease, TSPAP values are still consistently elevated to a greater degree than PAP at all clinical stages, with and without metastases. Regardless of the differentiation of the prostatic tumor, TSPAP levels were always more frequently elevated than PAP values. Tartrate-labile prostatic acid phosphatase (PAP) determinations are thus of no greater value in the diagnosis of prostatic carcinoma. In fact, total serum prostatic acid phosphatase is more sensitive and correlates better to the clinical stage of the disease and degree of differentiation of the primary tumor.
Rate of catalytic oxidation and decomposition of NADH by graphite in aqueous solutions

Graphites of different manufacture and origin exert positive but different accelerations on the rate of oxidation of NADH to NAD+ in aqueous solution; different proportions of the oxidized form of NAD retain enzymatic activity depending on the nature of the graphite. Oxidative pretreatment of the graphite surfaces increases the rates of NADH oxidation, but subsequent silanization of the surfaces to attach alkylamine groups causes the rates to decrease. The experimental results suggest the presence of at least two types of sites on graphite surfaces: One very reactive site which produces a high percentage of an enzymatically inactive reaction product of NADH and is itself deactivated during the course of reaction, and another type of site which promotes the oxidation of NADH to enzymatically active NAD+ in high yields.
Heterotrimeric G protein activation by G-protein-coupled receptors

Heterotrimeric G proteins have a crucial role as molecular switches in signal transduction pathways mediated by G-protein-coupled receptors. Extracellular stimuli activate these receptors, which then catalyse GTP-GDP exchange on the G protein alpha-subunit. The complex series of interactions and conformational changes that connect agonist binding to G protein activation raise various interesting questions about the structure, biomechanics, kinetics and specificity of signal transduction across the plasma membrane.
Allergic contact dermatitis from azathioprine

A 51-year-old production mechanic for a pharmaceutical company complained of a dermatitis involving his hands. The onset of the eruption coincided with when he was placed on the production packing line for azathioprine tablets. Patch testing showed a positive allergic reaction only to azathioprine diluted in petrolatum. A pharmaceutical product such as azathioprine may need to be considered as a cause for allergic contact dermatitis in patients with a history of exposure during the manufacturing process.
Identification of neuropsychological subtypes in a sample of delinquent adolescents

Although research has long recognized a relationship between neurological dysfunction and delinquency, the nature of this relationship is unclear. Based on the theory that there may be clusters of delinquents with different types of neurological dysfunction which contribute to the delinquency in different ways, the present research attempted to identify these subtypes using neuropsychological testing. Seventy-seven such adolescents were administered the full Luria-Nebraska Neuropsychological Battery-III (LNNB-III) and a battery of assessments measuring behavioral functioning and substance use. A Hierarchical Cluster Analysis yielded four identifiable neuropsychological clusters: Verbal/Left-Hemispheric Deficits, Subcortical-Frontal Deficits, Mild-Verbal Deficits, and Normals. The distinctiveness of these subtypes was confirmed by univariate analyses. Results further indicated that the number of LNNB scales that were in the abnormal range differed per subtype, with each subtype differing significantly from one another. These neuropsychological subtypes were found to be associated with specific psychological and behavioral problems.
Formation and exchange of deep water in the Greenland and Norwegian seas

Abstract The formation and exchange of deep water in the Greenland and Norwegian seas are modeled by a time-dependent box model. Using tritium and radiocarbon data, primarily from the Geochemical Sections (GEOSECS) 1972 operation, the time scale for deep convective mixing in the Greenland Sea is estimated to be about 30 years, which implies that about 100 m of surface water are mixed down annually. The time scale for exchange between the deep Greenland Sea and the deep Norwegian Sea is estimated to be at least 100 years. It appears, on the basis of tritium data, that the formation and exchange of deep water in the Greenland and Norwegian seas are essentially isolated from the formation of the dense overflow waters of the Denmark Strait and the Iceland-Faroe Passage.
Mechanisms and sites of mannitol permeability of small and large intestine in the rat

Mannitol is commonly used as an intestinal permeability probe, yet the mechanisms of its penetration of the intestinal barrier are not entirely clear. Therefore, we studied mannitol's permeability of different segments of the intestine and studied the kinetics and influence of intraluminal factors on mannitol permeabilityin vivo in perfused intestinal segments of rats. There was linear relationship between permeability rate of mannitol and its luminal concentration (y=7.2x+1.7;r=0.98), indicating that passive diffusion is involved in mannitol's permeability. Increased luminal fluid osmolarity from 0.3 to 0.6 osmol/liter resulted in decreased net water flux with a corresponding decrease in mannitol permeability in both jejunum and colon (P<0.01), indicating the prominent influence of solvent drag on net mannitol permeability. The relationship between mannitol permeability and water absorption at different osmolarities was linear in the jejunum and colon. At luminal osmolarity of 0.3 osmol/liter, 34.6% of mannitol permeability was mediated by passive diffusion and 65.4% was mediated by solvent drag in the jejunum. Mannitol permeability was much more dependent on solvent drag in the colon (88.9%) than in the small intestine (65.4%). The net permeability rate of mannitol was similar in the jejunum and ileum but was much higher in the colon (P<0.01). Addition of chenodeoxycholate (5 mM) to the perfusate resulted in a significant decrease in absorption of water (P<0.01) with a corresponding decrease in mannitol permeability (P<0.01). These studies indicate that mannitol permeability of the intestinal barrier is mediated by passive diffusion and solvent drag, with the latter accounting for a greater fraction of the total permeability.
Morphological Decomposition of 2-D Binary Shapes Into Modestly Overlapped Octagonal and Disk Components

One problem with several leading morphological shape representation algorithms is the heavy overlapping among the representative disks of the same size. A shape component formed by grouping connected disk centers may use many heavily overlapping disks to represent a simple shape part. Sometimes, these representative disks form complicated structures. A generalized skeleton transform was recently introduced which allows a shape to be represented as a collection of modestly overlapped octagonal shape parts. However, the generalized skeleton transform needs to be applied many times. Furthermore, an octagonal component is not easily matched up with another octagonal component. In this paper, we describe a octagon-fitting algorithm which identifies a special maximal octagon for each image point in a given shape. This transform leads to the development of two new shape decomposition algorithms. These algorithms are more efficient to implement; the octagon-fitting algorithm only needs to be applied once. The components generated are better characterized mathematically. The disk components used in the second decomposition algorithm are more primitive than octagons and easily matched up with other disk components from another shape. The experiments show that the new decomposition algorithms produce as efficient representations as the old algorithm for both exact and approximate cases. A simple shape-matching algorithm using disk components is also demonstrated
Growth-induced perpendicular magnetic anisotropy and clustering in NixPt1−x alloys

Abstract Polycrystalline and epitaxial (1 0 0), (1 1 0), and (1 1 1)-oriented Ni 3 Pt, NiPt, and NiPt 3 films were deposited over a range of growth temperatures from 80°C to 700°C. Films grown at moderate temperatures (200–400°C) exhibit growth-induced properties similar to Co–Pt alloys: enhanced and broadened Curie temperature, perpendicular magnetic anisotropy and large coercivity. As in Co–Pt, the magnetic properties suggest a clustering of Ni into platelets on the growth surface, as the films are being grown. Unlike Co–Pt, however, NiPt films exhibit a strong orientational dependence of anisotropy and enhanced Curie temperature, possibly resulting from different types of surface reconstructions which affect the growth surface.
Legionella Reveal Dendritic Cell Functions that Facilitate Selection of Antigens for MHC Class II Presentation

To understand how adaptive immune responses are generated against bacteria that avoid being delivered to lysosomes, interactions between professional antigen-presenting cells (APCs) and the intracellular pathogen Legionella pneumophila were examined. In contrast to murine bone marrow-derived macrophages (BMMs), we show that dendritic cells (DCs) restrict the growth of intracellular Legionella. Similar to what has been reported in BMMs, phagosomes containing Legionella matured into endoplasmic reticulum (ER)-derived organelles after DC internalization. Biogenesis of an ER-derived vacuole did not effectively sequester Legionella antigens from presentation on MHC class II molecules (MHC II). It was determined that proteins synthesized after Legionella had established residence in an ER-derived vacuole were presented by infected APCs. These data indicate that the ability of DCs to restrict intracellular growth of Legionella could be an important property that facilitates priming of protective T cell-mediated immune responses to vacuolar pathogens.
Cooperative Data Placement and Replication in Edge Cache Networks

Cooperation among individual caches has proven to be an effective strategy to improve the scalability and performance of edge cache networks delivering dynamic web content. To date, research in the area of cooperative edge caching has mainly focused on serving client requests and maintaining freshness of cached documents. However, designing mechanisms to effectively manage the available resources is an important challenge that can have significant impact on the performance of an edge cache network. In this paper we propose a novel data placement scheme, called the utility-based placement scheme, which is not only sensitive to the ongoing cooperation in the edge cache but also takes into account the various costs and benefits of storing a data-item at an individual edge cache. At the heart of proposed scheme is a utility function that quantifies the usefulness of storing a data-item at a particular edge cache. Experiments show that the proposed scheme provides significant performance benefits.
Irreversible wave-mean flow interactions in a mechanistic model of the stratosphere

A wave-1 minor warming is simulated in a mechanistic, global, primitive equation model. The modification of the zonal flow by the rearrangement of potential vorticity on a middle stratopheric isentrope is compared in a fully nonlinear model and in a model with only one wave and the zonal flow (a quasi-linear model). The permanent rearrangement of potential vorticity during the wave episode is more intense and more localized meridionally in the fully nonlinear model, which is able to capture the process of planetary wave breaking in some detail. Additional experiments reveal that the differences between the quasi-linear and nonlinear models persist for a broad range of wave amplitudes, and that the quasi-linear model can qualitatively reproduce the modification of the zonal flow by the wave when the diffusive dissipation of the wave is enhanced. These results are discussed in the context of the theory of barotropic Rossby waves in shear flows, and in comparison with recent numerical simulations of the middle atmosphere.
Spacetime encodings. III. Second order Killing tensors

This paper explores the Petrov type D, stationary axisymmetric vacuum (SAV) spacetimes that were found by Carter to have separable Hamilton-Jacobi equations, and thus admit a second-order Killing tensor. The derivation of the spacetimes presented in this paper borrows from ideas about dynamical systems, and illustrates concepts that can be generalized to higher-order Killing tensors. The relationship between the components of the Killing equations and metric functions are given explicitly. The origin of the four separable coordinate systems found by Carter is explained and classified in terms of the analytic structure associated with the Killing equations. A geometric picture of what the orbital invariants may represent is built. Requiring that a SAV spacetime admits a second-order Killing tensor is very restrictive, selecting very few candidates from the group of all possible SAV spacetimes. This restriction arises due to the fact that the consistency conditions associated with the Killing equations require that the field variables obey a second-order differential equation, as opposed to a fourth-order differential equation that imposes the weaker condition that the spacetime be SAV. This paper introduces ideas that could lead to the explicit computation of more general orbital invariants in the form of higher-order Killing tensors.
Efficient calculation of mass moments of inertia for segmented homogenous three-dimensional objects

The equations for the volume, centroid, and mass moments of inertia of a three-dimensional object are derived using Green's theorem. The object is assumed to be homogeneous and described as a stack of two-dimensional cross-sections. Given these assumptions, our approach using Green's theorem dramatically decreases data manipulation and computation as compared to the classical mass element summation technique employed for three-dimensional discrete objects. Although numerous factors influence accuracy, we chose to evaluate two representative objects in two orientations to determine the influence of the number of two-dimensional cross-sections on the accuracy of the calculations. For these shapes, 15 cross-sections per object were required to achieve relative error below 1%.
Cytochrome-free mitochondria of an anaerobic protozoan--Blastocystis hominis.

. Isolated mitochondria of the anaerobic protozoan Blastocystis hominis were subjected to spectral analysis, color, catalase, and peroxidase tests and found to be completely negative for cytochrome enzymes, catalase, and peroxide. Based on the absence of cytochrome enzymes, the possible evolution of B. hominis mitochondria from anaerobic bacteria is postulated.
Constrained TRPV1 agonists synthesized via silver-mediated intramolecular azo-methine ylide cycloaddition of α-iminoamides.

As part of an effort to identify agonists of TRPV1, a peripheral sensory nerve ion channel, high throughput screening of the NIH Small Molecule Repository (SMR) collection identified MLS002174161, a pentacyclic benzodiazepine. A synthesis effort was initiated that ultimately afforded racemic seco analogs 12 of the SMR compound via a silver mediated intramolecular [3+2] cycloaddition of an azo-methine ylide generated from α-iminoamides 11. The cycloaddition set four contiguous stereocenters and, in some cases, also spontaneously afforded imides 13 from 12. The synthesis of compounds 12, the features that facilitated the conversion of 12–13, and their partial agonist activity against TRPV1 are discussed.
Effect of epinephrine on norepinephrine release from rat kidney during sympathetic nerve stimulation

Abstract Experiments were performed to stydy presynaptic β-adrenoceptor facilitation of sympathetic neurotransmitter release in the isolated perfused rat kidney and evaluate the effect of epinephrine on norepinephrine release during sympathetic nerve stimulation. The right kidney was isolated and perfused with Krebs-Ringer solution. Norepinephrine storage sites were labelled with [3H]norepinephrine. Increasing concentrations of isoproterenol and salbutamol when perfused through the kidney, caused an enhancement of the stimulus-induced release of [3H]norepinephrine at 0.5 and 2 Hz, with the maximum facilitatory effect being observed at 0.5 Hz. The effect of salbutamol on [3H]norepinephrine release was concentration-dependent and more pronounced than that of isoproterenol. While propranolol (10−9−10−5 M) by itself did not cause any significant changes in the stimulus-induced release of [3H]norepinephrine, it antagonized the facilitatory action of salbutamol on [3H]norepinephrine release during periarterial nerve stimulation. When epinephrine (10−10−10−7 M), was perfused through the kidney in the presence of cocaine, it caused a concentration-dependent inhibition of the stimulus-induced release of [3H]norepinephrine at 0.5 Hz. In the presence of cocaine plus phentolamine epinephrine did not have any effect on [3H]norepinephrine release elicited during periarterial nerve stimulation. However, when epinephrine ws perfused in the presence of cocaine, phentolamine and corticosterone it caused a slight but significant increase in the stimulus-induced release of [3H]norepinephrine; the highest concentration (10−7) M) still caused a decrease in the [3H]norepinephrine release. These results, while providing evidence for the existence of presynaptic facilitatory β-adrenoceptors on renal sympathetic nerves, fail to support the hypothesis that these receptors have a physiological role in the regulation of sympathetic neurotransmitter release.
Nonlinear Kerr effect aperiodic Lüneburg lens

A subwavelength-modulated dielectric nonlinear Lu¨neburg lens is proposed and numerically verified. In the linear limit, the structure focuses a plane wave to an ideal geometrical point image. In the presence of Kerr nonlinearity, focal shift to a Gaussian beam input is compensated at a tunable intensity value. Nonlinear Lu¨neburg lens is also capable of finite conjugate imaging. A modified aperiodic Lu¨neburg is also proposed to greatly reduce the aberration caused by the Kerr effect.
Extrafamilial sexual abuse: treatment for child victims and their families ☆

Abstract Objectives: To decrease the emotional distress of child victims of extrafamilial sexual abuse (ESA) and their families. To provide crisis intervention, individual and group treatment in response to an expressed need in the community. To pilot the use of group treatment for child victims of ESA under age 10. Method: This discussion describes intervention with a sample of 246 child victims, ages 2–14 years, and 323 parents who participated in the program from 1984 to 1991. This pilot project operated at a university medical facility and was located off campus in an outpatient child abuse center. Priority was given to child victims under age 7. Child victims and their families were evaluated after investigative interviews by law enforcement agencies were completed. A treatment plan was developed based on clinical assessment. Families participated in crisis counseling, individual treatment for the child victim and/or parent, Children’s Treatment Groups, Parent Support Groups, or were referred to other resources. Clinical assessment of treatment progress included weekly case review by child and parent therapists, video analysis and observation of Children’s Treatment Group sessions, consultation with parents and collateral contacts. Results: A family approach and services for parents in addition to intervention for child victims were determined to be key components in facilitating recovery. Clinical observations and client feedback showed positive outcomes for child victims and parents with crisis counseling, Children’s Treatment groups, and Parent Support Groups. The extent of intervention ranged from one session to 24 months with an average participation of 6–9 months. Follow up surveys were returned by parents for 48 child victims and results are reported. Themes, parallels in responses, and recovery factors for child victims and parents are discussed. Conclusions: The need for intervention and a community-based program was demonstrated by (1) the significant disruption in functioning that occurred for child victims of ESA and their families, (2) the risk for long term sequelae, (3) the high incidence of extrafamilial sexual abuse, and 4) the consistent, large number of requests for services. Family-centered crisis services, Children’s Treatment Groups, and Parent Support Groups can be effectively based at child advocacy centers, out patient care clinics, or other community agencies. The results of formal outcome measures and longitudinal studies is needed to determine how child victims and parents benefit from specific treatment modalities and to better guide the use of limited resources.
Electron-microscopic cytochemical localization of diamine and polyamine oxidases in pea and maize tissues

An electron-microscopic cytochemical method was used to localize diamine oxidase (DAO) in pea and polyamine oxidase (PAO) in maize (Zea mays L.). The method, based on the precipitation of amine-oxidase-generated H2O2 by CeCl3, was shown to be specific for DAO and PAO and permitted their localization in plant tissues with a high degree of resolution. Both enzymes are localized exclusively in the cell wall. Both DAO- and PAO-activity staining is most intense in the middle lamellar region of the wall and in cells exhibiting highly lignified walls. The oxidases could provide H2O2 for peroxidase-mediated cross-linking reactions in the cell wall and may, in this capacity, play a role in the regulation of plant growth.
Estrogen mediation of injury‐induced cell birth in neuroproliferative regions of the adult zebra finch brain

Estrogens influence neuronal differentiation, migration, and survival in intact brains. In injured brains, estrogens can also be neuroprotective. In Experiment 1, following a unilateral penetrating injury to the hippocampus (HP), adult female zebra finches were injected once with BrdU to label mitotic cells then sacrificed 2 h, 1 day, or 7 days postinjection. Cell proliferation was dramatically enhanced in the ipsilateral HP, as well as in neuroproliferative areas including the subventricular zone (SVZ) proximal to the injury. This increase was seen at all time points investigated. Ovariectomy (OVX) substantially suppressed proliferation bilaterally especially in the SVZ indicating that gonadal hormones influenced cell proliferation in both the intact and injured hemisphere. To determine if estrogens were directly involved, estrogen was depleted in Experiment 2 through either OVX or administration of the aromatase inhibitor fadrozole (FAD). Birds were implanted with estradiol or blank followed 2 weeks later by a unilateral penetrating lesion to the HP. Injury-induced substantial proliferation, which was again significantly suppressed bilaterally in both OVX and FAD birds. Estrogen replacement reversed this effect in FAD but not OVX birds therefore the suppression following OVX may be due in part to nonestrogenic influences. Suppression of cell birth in FAD birds was indeed due to the removal of endogenous sources of estrogen. Results therefore indicate that estrogens are directly involved in the brain's response to injury and may be acting to provide a rich environment for the production and perhaps protection of new cells.
The Application of Real-Time PCR to Food and Agricultural Systems. A Review

Abstract Real-time PCR (RT-PCR) allows each cycle of DNA amplification to be observed on a computer screen throughout the sequence of thermal cycling, hence the designation “real-time.” RT-PCR assays have been developed for a variety of target sequences of food borne microbial pathogens, plant pathogens, and genetically modified foods. A major and highly sensitive aspect of RT-PCR is the use of fluorescent reporter dyes that undergo enhanced fluorescence when bound to DNA. Among the fluorescent reporter systems employed are SYBR green, and the molecular probes designated TaqMan, FRET, molecular beacons, and variations of these systems. A major advantage of RT-PCR involves the amplification of short DNA target sequences of 60–70-bp, which allows greatly reduced extension times, which when coupled with the advanced technology of RT thermal cyclers with reduced ramp times, greatly reduces cycle times so that amplified targets can be recognized within 30 min of amplification in some cases. Another major advan...
Apoptosis Generates Stable Fragments of Human Type I Keratins

Type I and II keratins help maintain the structural integrity of epithelial cells. Since apoptosis involves progressive cell breakdown, we examined its effect on human keratin polypeptides 8, 18, and 19 (K8, K18, K19) that are expressed in simple-type epithelia as noncovalent type I (K18, K19) and type II (K8) heteropolymers. Apoptosis induces rapid hyperphosphorylation of most known K8/18 phosphorylation sites and delayed formation of K18 and K19 stable fragments. In contrast, K8 is resistant to proteolysis and remains associated with the K18 fragments. Transfection of phosphorylation/glycosylation-mutant K8 and K18 does not alter fragment formation. The protein domains of the keratin fragments were determined using epitope-defined antibodies, and microsequencing indicated that K18 cleavage occurs at a conserved caspase-specific aspartic acid. The fragments are found preferentially within the detergent-insoluble pool and can be generated, in a phosphorylation-independent manner, by incubating keratins with caspase-3 or with detergent lysates of apoptotic cells but not with lysates of nonapoptotic cells. Our results indicate that type I keratins are targets of apoptosis-activated caspases, which is likely a general feature of keratins in most if not all epithelial cells undergoing apoptosis. Keratin hyperphosphorylation occurs early but does not render the keratins better substrates of the downstream caspases.
Transparent debugging of dynamically instrumented programs

Dynamic instrumentation systems, used for program analysis, bug isolation, software security and simulations, are becoming increasingly popular. There exists a need to debug dynamically instrumented programs while keeping the presence of dynamic instrumentation system hidden from debug users. Existing debuggers use debug information in program binaries that have been generated by a compiler at static compile time, to provide their debug support. Since dynamic instrumentation systems generate program code at run-time, existing debuggers are not able to provide the same kind of debug support. The most comprehensive existing debug techniques that satisfy this need, used by Tdb, require modification of existing debuggers. This paper provides an OS level approach that silently intercepts the communication between a debugger and the OS and uses a set of debug specifications to provide Tdb's transparent debugging. As a result, any existing debugger can be used to debug dynamically instrumented programs. The proposed techniques have been implemented on x86/Linux platform for the dynamic instrumentation system Pin.
A DYNAMIC MODEL OF MIGRATION WITH PUBLIC SECTOR ATTRIBUTES

The linkage between migration and sector characteristics is the subject of the paper. We analyze the impact of a tax rate change on a location's population and the accompanying, dynamic that occurs in the local labor market and public sector. Local labor market characteristics, tax price effects, and scale economics in consumption of a public good are found to influence the local population equilibrium.
Supergraphs and applications

The perturbative analysis of supersymmetric theories in terms of supergraphs serves two purposes: As a tool, for performing calculations in a simple and efficient fashion, and as a framework for proving theorems and obtaining insights (albeit misleading sometimes).
Sustainability of harvest of culpeo foxes in Patagonia

Wildlife hunting, for meat and skins, is an important component of the rural economy in Argentinian Patagonia. Every year thousands of fur-bearing mammals are killed and the impact of this on their populations is unknown. This paper reports on the results of a preliminary investigation into the sustainability of the harvest of culpeo foxes Dusicyon culpaeus in a 1000-sq-km area of Neuquen Province. Monitoring of fox densities and harvest rates over 5 years on six ranches revealed that, despite intense hunting, the numbers of foxes remained little changed. On the other hand, life-table analysis suggested that the levels of hunting pressure on four ranches were too high to allow fox populations to persist unless they were boosted by immigration. The findings have applications for wildlife managers in establishing sustainable harvest rates and optimal spatial distribution of those rates.
Facilitation and attenuation of a visceral nociceptive reflex from the rostroventral medulla in the rat

Abstract Background & Aims: Noxious inputs from somatic tissue are subject to biphasic descending modulation from the rostroventral medulla (RVM). In the present study, we investigated descending facilitatory and inhibitory influences from the RVM on a visceral nociceptive reflex. Methods: The visceromotor response (VMR), a contraction of peritoneal musculature during noxious colorectal distention (80 mm Hg, 20 seconds), was quantified as the integrated electromyogram. Results: At 22 sites in the RVM, electrical stimulation produced biphasic effects, facilitating the VMR at low (5, 10, and 25 μA) and inhibiting it at greater (>50 μA) intensities of stimulation. Electrical stimulation at all intensities tested (5–200 μA) in other sites in the RVM only inhibited (30 sites) or only facilitated (12 sites) the VMR to colorectal distention. Activation of glutamatergic receptors in the RVM replicated the effects of electrical stimulation. Reversible blockage (intraspinal lidocaine injection) or irreversible transection of spinal funiculi revealed that descending facilitatory influences from the RVM were conveyed in the ventrolateral/ventral funiculus, whereas descending inhibitory influences were contained in the dorsolateral funiculi. Conclusions: Spinal visceral nociceptive reflexes are subject to facilitatory modulation from the RVM, providing the basis for a mechanism by which visceral sensations can be enhanced from supraspinal sites. GASTROENTEROLOGY 2002;122:1007-1019
Heat-based dynamic data caching: A load balancing strategy for energy-efficient parallel storage systems with buffer disks

Performance improvement and energy conservation are two conflicting objectives in large scale parallel storage systems. In this paper, we propose a novel solution to achieve the twin objectives of maximizing performance and minimizing energy consumption of parallel storage systems. Specifically, a buffer-disk based architecture (BUD for short) is designed to conserve energy. A heat-based dynamic data caching strategy is developed to improve performance. The BUD architecture strives to allocate as many requests as possible to buffer disks, thereby keeping a large number of idle data disks in low-power states. This can provide significant opportunities for energy conservation while making buffer disks a potential performance bottleneck. The heat-based data caching strategy aims to achieve good load balancing in buffer disks and alleviate overall performance degradation caused by unbalanced workload. Our experimental results have shown that the proposed BUD framework and dynamic data caching strategy are able to conserve energy by 84.4% for small reads and 78.8% for large reads with slightly degraded response time.
Relationship Between Tympanic Membrane Perforations and Retained Ventilation Tubes

Objectives To determine the effects of prolonged ventilation tube retention on tympanic membrane healing and the efficacy of patching procedures used concomitantly at the time of tube removal. Design Retrospective chart review. Setting Tertiary referral academic institution. Patients Seventy-six patients aged 12 years and younger, with a total of 99 ears identified from January 1989 to December 1994. All patients underwent ventilation tube removal for prolonged tube retention or infection unresponsive to medical management. A minimum of 6 months of follow-up was required for inclusion. Intervention Ventilation tube removal under general anesthesia, with or without concomitant patching. Outcome Measures All medical charts were reviewed for age, sex, indications for tube removal, tube retention time, type of patch used (if any), type of tube, outcome after removal, other medical problems, and previous surgical history. Results The perforation rate was significantly higher in children with tubes retained beyond 36 months ( P =.02). History of previous adenoidectomy predicted poor outcome, with a rate of 47% vs 17% in patients with no such history ( P =.002). Patching did not improve healing. No other patient factors significantly influenced the perforation rate. Conclusions Ventilation tube retention longer than 36 months resulted in an increased perforation rate after surgical removal. Paper patching at the time of tube removal does not improve healing. Prospective studies are needed to confirm these findings and to determine the efficacy of other patching techniques.
New phases of zinc under pressure from first principles

A procedure for finding the many stable phases of an element under hydrostatic pressure p is discussed and applied to zinc. Five new phases are found with several different Bravais symmetries under the constraint of one atom per cell and their stabilities as functions of p calculated. The procedure seems generalizable to find all the phases in all Bravais symmetries in a given range of pressure. In particular fcc Zn, which is unstable at p = 0, is shown to be very stable above 320 kbar to at least 1000 kbar. In agreement with Muller et al. [Phys. Rev. B 60, 16448 (1999)], a rhombohedral (rh) phase is found to be stable at p = 0, and several more rh phases are found at pressures up to 320 kbar. The Gibbs free energies of all phases are evaluated as functions of p, and the pressures of thermodynamically favored phase transitions are found. The behavior of Zn is compared to similar behavior of vanadium, which also shows stable rh phases and cubic phase instability in a range of pressure; the bcc phase instability is also healed by additional pressure.
Qualitative optimization of image processing systems using random set modeling

Many decision-making systems involve image processing that converts input sensor data into output images having desirable features. Typically, the system user selects some processing parameters. The processor together with the input image can then be viewed as a system that maps the processing parameters into output features. However, the most significant output features often are not numerical quantities, but instead are subjective measures of image quality. It can be a difficult task for a user to find the processing parameters that give the 'best' output. We wish to automate this qualitative optimization task. The key to this is incorporation linguistic operating rules and qualitative output parameters in a numerical optimization scheme. In this paper, we use the test system of input parameter selection for 2D Wiener filtering to restore noisy and blurred images. Operating rules represented with random sets are used to generate a nominal input-output system model, which is then used to select initial Wiener filter input parameters. Whenthe nominally optimal Wiener filter is applied to an observed image, the operator's assessment of output image quality is used in an adaptive filtering algorithm to adjust the model and select new input parameters. Test on several images have confirmed that with a few such iterations, a significant improvement in output quality is achieved.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Hollow iron-silica nanoshells for enhanced high intensity focused ultrasound

Abstract Background High intensity-focused ultrasound (HIFU) is an alterative ablative technique currently being investigated for local treatment of breast cancer and fibroadenomas. Current HIFU therapies require concurrent magnetic resonance imaging monitoring. Biodegradable 500 nm perfluoropentane-filled iron-silica nanoshells have been synthesized as a sensitizing agent for HIFU therapies, which aid both mechanical and thermal ablation of tissues. In low duty cycle high-intensity applications, rapid tissue damage occurs from mechanical rather than thermal effects, which can be monitored closely by ultrasound obviating the need for concurrent magnetic resonance imaging. Materials and methods Iron-silica nanoshells were synthesized by a sol-gel method on polystyrene templates and calcined to yield hollow nanoshells. The nanoshells were filled with perfluoropentane and injected directly into excised human breast tumor, and intravenously (IV) into healthy rabbits and Py8119 tumor-bearing athymic nude mice. HIFU was applied at 1.1 MHz and 3.5 MPa at a 2% duty cycle to achieve mechanical ablation. Results Ex vivo in excised rabbit livers, the time to visually observable damage with HIFU was 20 s without nanoshells and only 2 s with nanoshells administered IV before sacrifice. Nanoshells administered IV into nude mice with xenograft tumors were activated in vivo by HIFU 24 h after administration. In this xenograft model, applied HIFU resulted in a 13.6 ± 6.1 mm 3 bubble cloud with the IV injected particles and no bubble cloud without particles. Conclusions Iron-silica nanoshells can reduce the power and time to perform HIFU ablative therapy and can be monitored by ultrasound during low duty cycle operation.
Strong and electromagnetic decays of two new Lambda c* baryons.

Two recently discovered excited charm baryons are studied within the framework of heavy hadron chiral perturbation theory. We interpret these new baryons which lie 308 MeV and 340 MeV above the ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}$ as I=0 members of a P-wave spin doublet. Differential and total decay rates for their double pion transitions down to the ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}$ ground state are calculated. Estimates for their radiative decay rates are also discussed. We find that the experimentally determined characteristics of the ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}^{\mathrm{*}}$ baryons may be simply understood within the effective theory.
Intermittent Faults: A Model and a Detection Procedure

Intermittent faults are those faults whose effects on the behavior of a system are present only part of the time. A probabilistic model for intermittent faults in digital circuits is suggested. A procedure for the detection of such faults in combinational circuits is proposed. The procedure employs the repeated application of tests that test for these faults as if their effects were permanent. The procedure is analogous to a sequential statistical decision problem. Least upper bounds on the number of repetitions of tests that detect a particular fault are derived. These bounds are then employed in designing optimum detection experiments. Such an optimization problem is found to be equivalent to an integer programming problem.
Incommensurate charge and spin fluctuations in d -wave superconductors

We show analytic results for the irreducible charge and spin susceptibilities ${\ensuremath{\chi}}_{0}(\ensuremath{\omega},\mathbf{Q}),$ where $\mathbf{Q}$ is the momentum transfer between the nodes in d-wave superconductors. Using BCS theory and a circular Fermi surface, we find that the singular behavior of the irreducible charge susceptibility leads to the dynamic incommensurate charge collective modes. The peaks in the charge structure factor occur at a set of wave vectors which form an ellipse around ${\mathbf{Q}}_{d}=(\sqrt{2}{k}_{F},\sqrt{2}{k}_{F})$ and ${\mathbf{Q}}_{0}=(0,0)$ in momentum space with momentum-dependent spectral weight. It is also found that, due to the nonsingular irreducible spin susceptibility, an extremely strong interaction via random phase approximation is required to support the magnetic peaks near ${\mathbf{Q}}_{d}.$
Compensation for hypercapnia by a euryhaline elasmobranch: Effect of salinity and roles of gills and kidneys in fresh water

Specimens of the euryhaline elasmobranch, Dasyatis sabina were acclimated to seawater and fresh water, and exposed to normocapnic (air) and hypercapnic (1% CO2 in air) environmental water. Blood pH, PCO2, and [HCO3-], as well as whole-animal net-acid excretion, were measured for up to 24 h of hypercapnia. In a separate experimental series, urine was collected from freshwater acclimated stingrays during 8 h of normocapnia and hypercapnia. Stingrays in both salinities at least partially compensated for the respiratory acidosis by accumulating HCO3- in their extracellular spaces. The degree of compensation for blood pH was 88.5% in seawater, but only 31.0% in fresh water after 24 h of hypercapnia. Whole-animal net-acid excretion was also greater in seawater than in fresh water, as was the increase in extracellular fluid [HCO3-]. Mean urinary net-acid excretion rates were slightly negative, and never increased above normocapnic control rates during hypercapnia. Since whole-animal net-acid excretion rates increased with blood [HCO3-], and urinary excretion was always negative, the gills were probably the primary organ responsible for compensation from environmental hypercapnia. The faster, and more complete, compensation for hypercapnia in seawater than in fresh water for this euryhaline elasmobranch is consistent with data for euryhaline teleosts, and probably reflects Na+-dependent mechanisms of branchial acid excretion.