cssi/SciSciGPT-SciSciNet huggingface dataset:
Peripherally Inserted Central Catheters: Outcome as a Function of the Operator

PURPOSE To determine the natural history of and outcome involved with peripherally inserted central catheters (PICCs) placed at a single institution and examine potential differences in the natural history of PICCs placed by interventional radiologists (IRs) versus registered nurses (RNs). MATERIALS AND METHODS A prospective analysis of all patients receiving PICCs at one academic medical center over a period of 6.5 months was conducted. At our institution, PICCs are placed primarily by RN members of the intravenous team. Placement procedures deemed unfeasible or problematic by RNs are referred to an IR for insertion under fluoroscopic guidance. A total of 322 PICCs (130 by IRs, 192 by RNs) were successfully placed in 256 patients. In three patients, placement was attempted but was a technical failure by both RNs and IRs. Seven patients in each group were lost to follow-up. PICCs were classified as successfully completed therapy or as having been prematurely removed, which was further stratified into suspected infection, occlusion, phlebitis, mechanical failure, inadvertent patient removal, and other. RESULTS Overall rate of premature removal for PICCs placed by IRs versus RNs was not significantly different (30.8% vs 23.4%, respectively). PICCs placed by IRs had an increased rate of occlusion (IRs = 9.2%, RNs=3.6%; P = .02). Other reasons for premature removal did not differ in incidence. Overall, PICCs were successfully placed in 99.1% of all patients and the course of therapy was completed in 69.3%. CONCLUSION It is reasonable and cost-effective for trained RNs to place PICCs whenever feasible and refer complicated placements to IRs.
Microemulsion polymerization. 1. Small-angle neutron scattering study of monomer partitioning

To achieve a better understanding of the kinetics of microemulsion polymerization, we have examined monomer partitioning between micelles and polymer particles during polymerization of aqueous micr...
Comment on ''Complex-particle emission in the pre-equilibrium exciton model''

Difficulties in the proposed formulation by Wu and Chang for emission rates of complex particles in the pre-equilibrium exciton model are discussed. Formal problems result in their derivation and in the equilibrium limit. Practical problems result from the neglecting of known direct reaction mechanisms.
BOVINE SERUM ALBUMIN IN LITHIUM CHLORIDE SOLUTIONS. CHANGES IN CONFORMATION

The physical state of bovine serum albumin in LiCl solutions at the pH near isoelectric point and room temperature has been studied with intrinsic viscosity, optical rotatory dispersion, circular dichroism and ultraviolet absorption difference spectra. The results indicate that the effects of Li+ take place in two processes. 1. At the concentration of LiCl below 4.0 M, only the general electrostatic effect occurs. There is no conformational change in the protein. 2. At the concentration of LiCl above 4.0 M, a specific effect of the Li+ occurs in which both the secondary and tertiary structures of the protein change. In addition, the protein molecules aggregate. In correspondence with the two processes, two different possible mechanisms are discussed.
Effect of water vapor on the activity and stability of Pd/SZ and Co/ZrO2 in dual-catalyst treatment of simulated exhaust from lean-burn natural gas engines

Abstract A dual-catalyst system, consisting of an NO oxidation catalyst component (Co/ZrO2) and a NOx reduction catalyst component (Pd/SZ) was investigated for selective catalytic reduction of NOx under lean conditions. The integrated catalyst system is capable of performing three-distinct catalytic functions, namely, NOx reduction, combustion of unburned hydrocarbons and oxidation of carbon monoxide. The hydrothermal stability of the dual-catalyst system was investigated through steady-state and time-on-stream measurements. Water vapor was found to inhibit the NOx reduction activity of Pd/SZ, whereas it had no effect on NO oxidation over Co/ZrO2. The dual-catalyst system was capable of retaining stable catalytic activity during simulated lean exhaust treatment in the presence of 7% H2O.
Elastin Haploinsufficiency Is Associated With Altered Interstitial Phenotype and Progressive Aortopathy

Supravalvular aortic stenosis (SVAS) [1] is a disease of the cardiovascular system that leads to narrowing of the large arteries in humans. Studies have shown [2] that SVAS is caused by mutations or deletions in the elastin gene resulting in elastin haploinsufficiency. Elastin haploinsufficiency results in systemic hypertension [3], thinner and more numerous elastic lamellae [4], and altered arterial mechanics [5]. Genetically modified elastin deficient mice (ELN+/-) recapitulates the human phenotype including obstructive arterial disease and decreased arterial compliance [1,3]. Elastin deficiency in these mice is associated with changes in the mechanical microenvironment in the vascular wall [6], including enhanced wall thickness, increased smooth muscle cell (SMC) proliferation [7] and stiffening of arteries [8]. However, the molecular mechanisms for these changes are not fully understood. Also from a developmental perspective, no information is available regarding initiation and progression of aortic pathology in ELN+/− mice with time. The objectives of this study were to determine the temporal effects of elastin haploinsufficiency on the functional properties of aortic tissue and the aortic cell phenotype, using the elastin deficient mouse model (ELN+/-). We hypothesized that elastin haploinsufficiency will result in progressive abnormalities in aortic stiffness and dynamic alterations in aortic smooth muscle cell phenotype.Copyright © 2008 by ASME
Enantioselective synthesis of 11-hydroxy-(1′S,2′R)-dimethylheptyl-Δ8-THC, a very potent CB1 agonist

Abstract An enantioselective synthesis of the (1S,2R)-dimethylheptyl cannabinoid side chain has been developed and employed in the synthesis of 11-hydroxy-(1′S,2′R)-dimethylheptyl-Δ8-THC, one of the most potent traditional cannabinoids known. The synthesis involves a highly stereoselective addition of dimethylcopperlithium to an enoyl sultam which incorporates Opplozer's auxiliary.
Delirium and other clinical factors with Clostridium difficile infection that predict mortality in hospitalized patients.

Background Clostridium difficile infection (CDI) severity has increased, especially among hospitalized older adults. We evaluated clinical factors to predict mortality after CDI. Methods We collected data from inpatients diagnosed with CDI at a U.S. academic medical center (HSR-IRB#13630). We evaluated age, Charlson comorbidity index (CCI), whether patients were admitted from a long-term care facility, whether patients were in an intensive care unit (ICU) at the time of diagnosis, white blood cell count (WBC), blood urea nitrogen (BUN), low body mass index, and delirium as possible predictors. A parsimonious predictive model was chosen using the Akaike information criterion (AIC) and a best subsets model selection algorithm. The area under the receiver operating characteristic curve was used to assess the model's comparative, with the AIC as the selection criterion for all subsets to measure fit and control for overfitting. Results From the 362 subjects, the selected model included CCI, WBC, BUN, ICU, and delirium. The logistic regression coefficients were converted to a points scale and calibrated so that each unit on the CCI contributed 2 points, ICU admission contributed 5 points, each unit of WBC (natural log scale) contributed 3 points, each unit of BUN contributed 5 points, and delirium contributed 11 points.Our model shows substantial ability to predict short-term mortality in patients hospitalized with CDI. Conclusion Patients who were diagnosed in the ICU and developed delirium are at the highest risk for dying within 30 days of CDI diagnosis.
Perturbative effective theory in an oscillator basis

The effective interaction problem in nuclear physics is believed to be highly nonperturbative, requiring extended high-momentum spaces for accurate solution. We trace this to difficulties that arise at both short and long distances when the included space is defined in terms of a basis of harmonic oscillator Slater determinants. We show, in the simplest case of the deuteron, that both difficulties can be circumvented, yielding highly perturbative results in the potential even for modest (approximately 4 variant Planck's over 2pi omega) included spaces.
Emissivities of diffuse cavities. III. Isothermal and nonisothermal double cones

Local hemispherical effective emissivities and integrated cavity emissivities are computed for isothermal and nonisothermal diffuse double cones (a conical section joined to a conical frustum) with and without lids, and are compared with corresponding values for cylindrocones. The local emissivities increase and become more uniform with increasing taper of the frustum. They are also considerably higher when there is a lid. For cavities with the same conical section, length, and aperture, a lidded double cone is blacker than a lidded cylindrocone when the front half of the frustum is invisible, but less black otherwise. For double cones of the same length, diameter, and aperture, the best choice of cone and frustum angles depends upon the particular viewing conditions. The integrated cavity emissivities vary only slightly with the angles of cone and frustum when the frustum is relatively long, and the normal emissivity (for a small on-axis detector a large distance away) is higher than the hemispherical emissivity (for a detector that fills the cavity aperture). When the frustum is relatively short, all of these vary substantially with angle, and the hemispherical emissivity can be higher than the normal emissivity. There is a marked variation of both local and integrated emissivities with wavelength in nonisothermal double cones; e.g., for the particular cases illustrated, the normal spectral emissivities change by from 4% to 6% and the hemispherical spectral emissivities by from 17% to 20% between 0.3 and 1 μm for a 1% temperature variation at 1300 K. The amount of the change in these spectral emissivities also depends upon the geometry of the cavity.
A quantitative comparison of cell-type-specific microarray gene expression profiling methods in the mouse brain.

Expression profiling of restricted neural populations using microarrays can facilitate neuronal classification and provide insight into the molecular bases of cellular phenotypes. Due to the formidable heterogeneity of intermixed cell types that make up the brain, isolating cell types prior to microarray processing poses steep technical challenges that have been met in various ways. These methodological differences have the potential to distort cell-type-specific gene expression profiles insofar as they may insufficiently filter out contaminating mRNAs or induce aberrant cellular responses not normally present in vivo. Thus we have compared the repeatability, susceptibility to contamination from off-target cell-types, and evidence for stress-responsive gene expression of five different purification methods - Laser Capture Microdissection (LCM), Translating Ribosome Affinity Purification (TRAP), Immunopanning (PAN), Fluorescence Activated Cell Sorting (FACS), and manual sorting of fluorescently labeled cells (Manual). We found that all methods obtained comparably high levels of repeatability, however, data from LCM and TRAP showed significantly higher levels of contamination than the other methods. While PAN samples showed higher activation of apoptosis-related, stress-related and immediate early genes, samples from FACS and Manual studies, which also require dissociated cells, did not. Given that TRAP targets actively translated mRNAs, whereas other methods target all transcribed mRNAs, observed differences may also reflect translational regulation.
Dynamics of propagation of premature impulses in structurally remodeled infarcted myocardium: a computational analysis

Initiation of cardiac arrhythmias typically follows one or more premature impulses either occurring spontaneously or applied externally. In this study, we characterize the dynamics of propagation of single (S2) and double premature impulses (S3), and the mechanisms of block of premature impulses at structural heterogeneities caused by remodeling of gap junctional conductance (Gj) in infarcted myocardium. Using a sub-cellular computer model of infarcted tissue, we found that |INa,max|, prematurity (coupling interval with the previous impulse), and conduction velocity (CV) of premature impulses change dynamically as they propagate away from the site of initiation. There are fundamental differences between the dynamics of propagation of S2 and S3 premature impulses: for S2 impulses |INa,max| recovers fast, prematurity decreases and CV increases as propagation proceeds; for S3 impulses low values of |INa,max| persist, prematurity could increase, and CV could decrease as impulses propagate away from the site of initiation. As a consequence it is more likely that S3 impulses block at sites of structural heterogeneities causing source/sink mismatch than S2 impulses block. Whether premature impulses block at Gj heterogeneities or not is also determined by the values of Gj (and the space constant λ) in the regions proximal and distal to the heterogeneity: when λ in the direction of propagation increases >40%, premature impulses could block. The maximum slope of CV restitution curves for S2 impulses is larger than for S3 impulses. In conclusion: (1) The dynamics of propagation of premature impulses make more likely that S3 impulses block at sites of structural heterogeneities than S2 impulses block; (2) Structural heterogeneities causing an increase in λ (or CV) of >40% could result in block of premature impulses; (3) A decrease in the maximum slope of CV restitution curves of propagating premature impulses is indicative of an increased potential for block at structural heterogeneities.
The Polish vowel dispalatalization and its environment

Abstract The Polish dispalatalization of vowels was the change of nonhigh front vowels to back vowels when followed by a nonpalatalized dental consonant. This highly unusual environment has never been adequately explained. This paper proposes that the solution may be found in the transfer of synharmonic redundancy from syllabic initial to syllabic final in order to save incipient dental palatalization from extinction. This suggests a new relative chronology, according to which Polish dispalatalization of vowels occurred only after the dispalatalization of final labial consonants, which in turn followed jer-loss. The distinctive feature system of Fundamentals of language , together with a new synharmony feature, are shown to best represent this process in distinctive features.
A Reprise, Or Round Three: Using a Database Management Program as a Decision-Support System for the Cancellation of Serials

Annual journal inflation rates of eight percent or higher have compelled libraries to cancel journals. Since 1992 Purdue Libraries have had three major cancellation projects. This article reviews how the Humanities, Social Science and Education Library approached this task in 2009 and developed a database management program to identify titles based on two criteria: low use and the availability of the title in full text in one of three aggregator databases. The education and humanities departments reached the cancellation goal, but several social science departments had to transfer funds from the book budget to accommodate their journal subscription costs. This indicates the importance of the journal to research in these areas.
Development and validation of the Psychological Adaptation Scale (PAS): use in six studies of adaptation to a health condition or risk.

Objective We introduce The Psychological Adaptation Scale (PAS) for assessing adaptation to a chronic condition or risk and present validity data from six studies of genetic conditions.
The fracture resistance of a model metal/ceramic interface

Abstract Crack propagation has been measured for the Al2O3/Au interface subject to conditions that exclude stress corrosion. Crack growth has been shown to occur with a rising resistance, governed by intact metal ligaments in the crack wake. The level of resistance also increases as the metal layer thickness increases. Crack extension occurs by a combination of plastic void growth and interface debonding. The fracture energies are much larger than the work of adhesion, but appreciably smaller than those expected for ductile interface fracture. The fracture energy is nevertheless dominated by plastic dissipation, which increases at larger metal layer thicknesses.
Two-ion superradiance theory

A superradiance theory is developed for two identical hydrogenic ions (four states each) in a microtrap, as in recent experiments. The ions oscillate (micromotion) due to the trap's radio frequency (rf) electric quadrupole field. One signature of superradiance is a deviation of the two-ion average upper state decay rate \ensuremath{\gamma}\ifmmode\bar\else\textasciimacron\fi{} from the one-ion value \ensuremath{\gamma}. A master equation is derived, giving a fractional change in the upper state lifetime \ensuremath{\gamma}/\ensuremath{\gamma}\ifmmode\bar\else\textasciimacron\fi{}-1=sinkR/2kR [${\mathit{J}}_{0}^{2}$(z)-2${\mathit{J}}_{1}^{2}$(z)+...]cos\ensuremath{\Phi}, where k=2\ensuremath{\pi}/\ensuremath{\lambda}, \ensuremath{\lambda} is the emission wavelength, R is the ion-ion distance, ${\mathit{J}}_{\mathit{n}}$(z) is a Bessel function of integer order n, and z=ka, a is the ion amplitude of motion, and \ensuremath{\Phi} is the two-ion relative phase due to the preparation. In the Lamb-Dicke regime, a, ${\mathit{J}}_{0}^{2}$(z)\ensuremath{\approxeq}1 and thus superradiance is not influenced significantly by ion motion. This damped sinusoid is diluted by the factor of 1/2 due to destructive interference. Superradiance vanishes in the absence of coherent preparation, e.g., with inversion, as indicated by the time evolution of the two-ion dipole correlation function. Fringes and a beat at the rf are predicted in forward scattering, the most elementary form of optical free induction decay.
Why employment in integrated settings for people with disabilities

This paper reviews the reasons why work in integrated settings for people with disabilities is important. Current controversial issues in employment of people with disabilities are discussed. These issues are sheltered work versus supported employment and natural supports versus the job coach model. Warum eine integrierte Beschaftigung von Menschen mit Behinderungen? Der Beitrag untersucht die Grunde, warum fur Menschen mit Behinderungen ein integriertes Arbeitsumfeld wichtig ist. Erortert werden aktuell kontrovers diskutierte Fragen in Zusammenhang mit der Beschaftigung behinderter Menschen, insbesondere die Themen geschutztes Arbeitsumfeld versus unterstutzte Beschaftigung sowie ‘naturliche’ Unterstutzung durch Arbeitskollegen versus das ‘Job Coach’-Modell. Pourquoi Employer les Handicapes dans des Centres Integres Cet article presente les raisons de l'importance de fournir des emplois aux handicapes dans des centres integres et discute des controverses actuelles sur l'emploi des handicapes. Ces controverses sont les suivantes: atelier speciaux pour handicapes contre postes de travail integres et integration naturelle contre modele du travail dirige. Pensamiento, consideracion y planificacion futura de un posible traslado fuera del hogar de los hijos adultos con discapacidad psiquiatrica por parte de los padres cuidadores Se estudiaron los pensamientos, consideraciones y planes futuros de un posible traslado fuera del hogar de los hijos adultos con discapacidad psiquiatrica (n = 89) por parte de los padres cuidadores israelies. Se consideraron como variables del traslado la edad, la tension emocional (conyugal, paterna, domestica), la valoracion cognitiva, el apoyo social y la autoestima. Los hallazgos principales revelan que una baja tension psiquica de los padres se correlaciona con pensamientos y consideraciones referentes al traslado de los hijos fuera del hogar, mientras que una baja tension conyugal se asocia a planes futuros en ese mismo sentido. Mediante un analisis de regresion se comprobo que una baja tension conyugal de los padres es un factor de prediccion de pensamientos y consideraciones en relacion con el traslado fuera del hogar de los hijos, mientras que una baja valoracion cognitiva de los padres es un factor predictivo de la realizacion de planes futuros al respecto.
Clinical classification of regional cerebral blood flow (RCBF) by partitioning

An algorithm is proposed to classify the regional cerebral blood flow (RCBF) of two groups of subjects. A 32-tuple training vector is defined corresponding to 32 detectors used to measure 133Xe washout following inhalation. For any index of 133Xe washout, each detector is associated with two cumulative distributions (cds) each corresponding to a population. The 32 index values at which the differences between cds are maximum are defined as partition values. All index values are then compared to their partitions and are designated binary values of 1 or 0 for being above or below the partitions. A representative sum of the binary numbers (0 to 16) indicates the number of detectors in each hemisphere which exceed their respective threshold. In the example, a normal group of subjects (n = 40) is compared to an abnormal group (n = 82). The abnormal group was identified independently of RCBF by clinical testing as having Alzheimer's disease, a subcategory of dementing diseases. The classification algorithm defined a training vector to which the two populations were compared. The normal subjects had higher representative scores than the abnormals with a tight clustering of these scores. Although some abnormals scored well, the great majority had representative scores well below 12 for each cerebral hemisphere. The training vector can be used to classify new studies or can be updated by new studies until no significant changes result. At this point, the new tracing vector is used as a reference set of partition values.
Abstract 3798: Heat shock cognate protein HSPA8 (Hsc70) regulates migration and xenograft growth of breast tumor cell lines.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC In order to identify genes involved in the metastatic phenotype we had previously developed isogenic cell lines from the human breast carcinoma cell line MDA-MB-435 that have different metastatic phenotypes in immunocompromised mice. Proteomic profiling of the extracellular component of this model identified the heat shock cognate protein HSPA8 (Hsc70) as over-expressed in the metastatic cell line (M4A4) relative to its non-metastatic counterpart (NM2C5). Heat shock proteins are primarily implicated in a cytoprotective role when cells are exposed to stressful stimuli. They are intracellular molecular chaperones but are also found in the surface of embryonic stem cells and a variety of tumor cells. With the purpose of investigating the role of HSPA8 in tumor growth and metastasis, we first verified that this protein was expressed on the cell surface and in the conditioned medium of M4A4 cells, in addition to its intracellular location. Then we generated stable HSPA8 knockdown clones of the M4A4 cells and cell behavior was tested in a panel of analyses in vitro and xenograft growth was tested in immunocompromised mice. Knockdown of HSPA8 expression in M4A4 cells resulted in reduction of cell doubling time and of their migration potential in vitro. When individual M4A4-HSPA8 knocked down cell clones were injected into the mammary fat pad of immunocompromised mice significant reduction of the tumor size was observed relative to non-silencing control cells. The invasive and metastatic potential of the M4A4-HSPA8 knockdown clones as well as their transcriptional profile are currently under investigation. Our findings suggest that HSPA8 plays a role in cell growth in vitro and in vivo and may be involved in metastasis of breast cancer cells. Extracellular heat shock proteins have recently been shown to mediate a range of powerful effects in inflammatory, neuronal and immune cells through a number of cell surface receptors. The mechanisms involved in tumor dissemination and metastasis are potential targets for therapeutic intervention Citation Format: Maria F. Pino, Ge Zhang, Charles J. Rosser, Steve Goodison, Virginia Urquidi. Heat shock cognate protein HSPA8 (Hsc70) regulates migration and xenograft growth of breast tumor cell lines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3798. doi:10.1158/1538-7445.AM2013-3798
Toxaphene in Great Lakes fish: a temporal, spatial, and trophic study

We report here on the concentrations of toxaphene, a complex mixture of hexa- to decachlorinated norbornanes and norbornenes, in Great Lakes' lake trout and smelt sampled in 1982 and 1992. Lake trout from Lakes Superior, Michigan, and Huron had higher lipid-normalized toxaphene concentrations than the smelt, while in Lakes Ontario and Erie both trophic levels had about the same concentrations. Concentrations in both species declined between 1982 and 1992, with the exception of Lake Superior, where there was no significant difference. Except for the Lake Superior samples, these trends were expected because toxaphene was banned in the United States in 1982. The fact that the Lake Superior samples did not show lower concentrations over time suggests that there may be some lake-specific source that is continuing to load toxaphene into Lake Superior or that toxaphene is not being removed from Lake Superior as quickly as the other Great Lakes.
Effects of cerium addition on CO oxidation kinetics over alumina-supported rhodium catalysts

Abstract The kinetics of CO oxidation in a strongly oxidizing environment (i.e., P O 2 ⪢ P CO ) over a low-loaded Rh/Al 2 O 3 catalyst are not significantly affected by the presence of cerium. Under moderately oxidizing or net-reducing conditions, on the other hand, the addition of sufficient amounts of cerum oxides (≥2 wt% Ce) to the Rh/Al 2 O 3 catalyst was found to cause the following changes in CO oxidation kinetics: suppression of the CO inhibition effect, decreased sensitivity of the reaction rate to gas-phase O 2 concentration, and decreased apparent activation energy. These cerium-induced changes in the kinetics lead to enhancement of CO oxidation activity and can be rationalized on the basis of a mechanism involving CO 2 formation via a reaction between CO adsorbed on Rh and surface oxygen derived from the neighboring ceria particles. The effects of Ce addition on the CO oxidation kinetics were also independent of whether the Ce was deposited before or after the Rh.
Use and Disuse of Contextual Primes in Dynamic News Environments

This study reexamines the news priming effects of the 1991 Persian Gulf War. Suggesting an alternative approach to those used in previous studies, this study assesses individuals' use and disuse of a contextual prime (i.e., the air war) in dynamic news environments. With a short-term, quasi-experimental approach considering the air war as a prime stimulus, a path analysis suggests robust evidence of the short-term accessibility effects of priming. More importantly, as suggested in Martin's (1986) set/reset model, this study extends priming effects beyond the simple hydraulic patterns of accessibility effects. It reveals that both attitudes toward military action and attitudes toward a diplomatic solution were used in subsequent judgments of the president's job performance and handling of the war. The associations between attitudes toward a diplomatic solution and subsequent judgments were even stronger than those between attitudes toward military action and the same subsequent judgments, despite the clear prowar primes of news discourse in the air-war context. This pattern was more greatly intensified among those in the high news attention group than those in the low news attention group.
Footprints of a Pleistocene hominid in northern Kenya

We report here that in 1978, while studying Koobi Fora Formation sedimentary environments and fossils in northern Kenya, we discovered single footprints and trails of large vertebrates in a number of different strata. One of these trails is that of a bipedal hominid, the second known record of early hominid tracks in Africa, the other being that reported at Laetoli, Tanzania1.
Putting out the fire before it starts: proactive technology support

At Bucknell University, the Technology Support workgroup has initiated a proactive approach to faculty and staff desktop computing support. Through the use of scanning and monitoring tools, we seek to identify and eliminate potential problems before the client can be disrupted or inconvenienced.We currently have several tools that allow us to distribute timely information to the client. These tools include the opening greeting heard by callers of our technology support number, a web based campus outage and alert center, a custom outage-alert/popup program on the client's computer, portal access to our problem tracking system, and numerous training sessions.Technology Support has also bought and developed several tools to gather information from the client's computers in order to identify machines that will soon be having trouble. These tools help us remotely identify failing hard drives, identify disks approaching capacity, and identify and sometimes fix other preventable problems.Our Technology Support workgroup currently manages an array of centrally managed, preventative maintenance services for our clients, including anti-virus, anti-spyware, windows patching (via WSUS) and centralized, network backup of all faculty and staff desktops.Thanks to our use of proactive tools, we have been able to reduce the number of emergency calls and lower the downtime experienced by our clients. Proactive computing support is better for Technology Support staff and for the university than the reactive/crisis model.
NMR relaxation rate and the libron energy of solid hydrogen

By taking the rotational relaxation of orthohydrogen (o-H2) in solid hydrogen into account, the authors have theoretically investigated the longitudinal NMR spin lattice relaxation rate of o-H2. The rate is characterized by an anomalous maximum, as a function of temperature, at temperatures close to the mean libron energy of o-H2. Application of the theory for o-H2 concentrations between 42% and 75% reveals a nearly concentration-independent mean libron energy equivalent to about 1 K. This qualitatively and quantitatively contradicts the conclusions of other theories, but agrees with recent experiments.
Spectrally selective infrared absorption enhancement in photonic crystal cavities

Infrared photodetectors with spectrally selective response are highly desirable for applications such as hyper-spectral imaging and gas sensing. Owing to the ability of photonic density of states modification and dispersion engineering, photonic crystals appear to be one of the most promising platforms for infrared photodetectors with spectrally-selective absorption enhancement. We report here the latest advances on 1D and 2D dielectric photonic crystal structures for infrared photodetectors, based on defect mode, bandedge effect and the guided mode resonance/Fano effects. High spectral selectivity and tunability is feasible with defect mode engineering, making photonic crystal defect cavities a promising nanophotonic platform for the spectrally selective infrared sensing and hyper-spectral imaging, with the incorporation of quantum well or quantum dot infrared photodetector heterostructures.
Dispersion relations and sum rules for magnetoreflectivity

Dispersion relations and sum rules for the dichroic reflectivity and phase shifts of circularly polarized modes are developed for the magneto-optical case. The reduction in crossing-relation symmetry arising from the presence of a magnetic field and the consequent non-Kramers-Kronig form of the dichroism dispersion relations are discussed in terms of the analyticity of the amplitude reflectivity. Sum rules are derived from the low- and high-frequency limits of the dichroism dispersion relations. These rules include the general results that ∫0∞ω-1 ln[r+(ω)/r-(ω)]dω=0 and ∫0∞[θ+(ω)-θ-(ω)] dω=πωc, where r±(ω) and θ±(ω) are the amplitude and phase of the amplitude reflectivity for the circular modes and ωc is the cyclotron frequency. Approximate finite-energy dispersion relations and sum rules are developed and their range of validity examined.
Age‐Dependent Relationships Among Pain, Depressive Symptoms, and Functional Disability in Youth With Recurrent Headaches

Objective.—To assess age differences associated with depressive symptoms and functional disability in children and adolescents with recurrent headache. Background.—Research has indicated that psychological factors, especially depression, are related to the extent and nature of functional disability experienced from headaches. There is a lack of research examining how age impacts the relationship between pain, psychological factors, and activity restriction in children and adolescents with recurrent headache. Methods.—Seventy-seven participants from a pediatric neurology clinic completed self-report measures of pain intensity, depressive symptoms, and functional disability. Results.—Findings demonstrated a significant positive correlation between pain and functional disability, and depressive symptoms and functional disability for children. Correlations for adolescents failed to reach significance. Functional disability emerged as a mediator between headache pain and depressive symptoms for children but not for adolescents. Conclusions.—Results indicate potentially important age differences when examining the impact of functional disability on depressive symptoms in this sample. Findings suggest that functional disability may contribute to depressive symptoms differently for children versus adolescents with recurrent headache. Age-specific interventions that differentially focus on the specific roles that pain, depressive symptoms, and disability have for children and adolescents with recurrent headache may be warranted.
Age and Gender Differences in Adolescents' Homework Experiences.

Extant data collected through the Experience Sampling Method were analyzed to describe adolescents' subjective experiences of homework. Analyses explored age and gender differences in the time adolescents spend doing homework, and the situational variations (location and companions) in adolescents' reported concentration, effort, interest, positive affect and stress while doing homework. Regarding age differences, middle school students reported more positive experiences when homework was done with companions and in locations other than home, whereas high school students reported more positive experiences when homework was done alone and at home. Regarding gender differences, girls, regardless of age, reported greater stress than boys when doing homework alone, and lower stress when doing homework with friends. High school girls reported lower interest than middle school boys when doing homework alone. Findings provide an understanding of age and gender differences in adolescents' perceptions of homework, which might help educators and parents structure engaging homework environments.
On Rubbing Raw the Sores of Discontent: Competing Theories and Data on the Effects of Participation in a Black Protest Group

Predictions concerning the effects of participation in protest activity stimulated by conflict and resentment are derived from two theories of attitude change, sociotherapy and dissonance reduction...
Changes in Biotic Integrity of a River in North-Central Tennessee

Abstract Fish species composition and index of biotic integrity of Roaring River, Tennessee, were assessed in 1972 and 1986. During the intervening years, a fish barrier dam was constructed in the river, heavy gravel dredging occurred, and the watershed was disturbed by bridge construction, highway construction, and poor agricultural practices. Species composition changes and a general decline in index values reflected these instream and watershed disturbances. Deliberate and inadvertent introductions of new fish species also contributed to these changes. There was a general decline in number of native species, a loss of intolerant species in the lower reaches, and a general increase in tolerant species. There was also an increase in number of introduced species in the lower reaches, and a general increase in percentage of the population consisting of introduced species.
Construction and analysis of a semi-quantitative energy profile for the reaction catalyzed by the radical enzyme galactose oxidase

Abstract Galactose oxidase (GOase) is a mononuclear type 2 copper enzyme which oxidizes primary alcohols to aldehydes using molecular oxygen (RCH 2 OH+O 2 =RCHO+H 2 O 2 ). An unusual crosslink between tyrosine 272 and cysteine 228 provides a modified tyrosine radical site which acts as a ligand for the active site copper and is believed to act as a one-electron redox center. The single active site copper is believed to act as a second one-electron redox center. The use of the tyrosine one-electron redox center and the copper one-electron redox center allows removal of two electrons from alcohol substrate for subsequent transfer to molecular oxygen. Previously, we and others have proposed a detailed step-by-step radical mechanism for the reaction catalyzed by galactose oxidase. The catalytic cycle can be divided into two half reactions. The first half reaction entails transfer of two electrons and two protons from the alcohol substrate to the enzyme to form aldehyde product and two-electron-reduced enzyme (one electron at the tyrosine center and one at the copper center). The second half reaction entails transfer of two electrons and two protons from the two-electron-reduced enzyme to O 2 to form H 2 O 2 product and regenerate fully oxidized catalytically active enzyme ready for another catalytic cycle. In this paper, we describe the construction of a semi-quantitative energy profile for this radical mechanism. Several significant points emerge from this analysis. One point is the prediction that galactose oxidase should have an unusually low redox potential for copper, to our knowledge lower than any other redox active copper protein. Another point is that the distorted or entatic copper site causes the unusually low redox potential. A final point is that crosslinking of tyrosine 272 and cysteine 228 alters the redox properties of the tyrosine center to enhance catalysis compared to what would be expected for a normal tyrosine.
Adherence and internalization of Streptococcus uberis to bovine mammary epithelial cells are mediated by host cell proteoglycans

The role of cell glycosaminoglycans (GAG) on adherence and internalization of Streptococcus uberis to bovine mammary epithelial cells was evaluated by adherence/internalization competition assays, by removal of GAG from the host cell surface and by inhibition of GAG glycosylation in the host cell. Heparin (HEP), heparan sulfate (HSA), chondroitin sulfate A (CSA) and chondroitin sulfate B (CSB) inhibited adherence and internalization of S. uberis in a dose-dependent manner. However, inhibition was lower with CSA and CSB than that observed with HEP and HSA. Adherence and internalization were also inhibited upon treatment of mammary epithelial cells with GAG lyases. The greatest inhibition was observed with heparinase I. Tunicamycin, an inhibitor of mammalian cell glycosylation of cell surface glycoproteins, markedly inhibited internalization of S. uberis into mammary epithelial cells. Differences between strains were observed. These results suggest that a HSA proteoglycan receptor on the host cell surface may mediate S. uberis adherence to and internalization of bovine mammary epithelial cells.
Synthesis of 1-O-Alkyl-3-O-phosphorylethanolamine-2-propanone and Related Derivatives

The synthesis and characterization of 1-O-hexadecyl-and 1-O-octadecyl-3-O-phosphorylethanolamine-2-propanone are described. Ketal derivatives of these compounds were isolated and purified by column chromatography on silica gel in an overall yield of 21 and 27%. The availability of these new keto phospholipids could be important in biosynthetic studies of alkyl glycerolipids, plasmalogens, and related derivatives.
Mitogen-activated Ca++ channels in human B lymphocytes.

Two complementary experimental methods have been used to examine mitogen-induced transmembrane conductances in human B cells using the Daudi cell line as a model for human B cell activation. Spectrofluorometry was used to investigate mitogen-induced changes in [Ca++]i and transmembrane potential. Activation of human B cells with anti-μ antibodies resulted in a biphasic rise in [Ca++]i, the second phase being mediated by the influx of extracellular Ca++. Ca++ influx was inhibited by high [K+]e, suggesting that this influx was transmembrane potential sensitive. Membrane currents of Daudi cells were investigated using voltage clamp techniques. Before mitogenic stimulation, the cells were electrically quiet. Within several minutes of the addition of anti-μ antibodies to the bath solution, inward currents were observed at negative voltages. Whole-cell currents changed instantly with voltage steps and were transmembrane potential sensitive in that at potentials more positive than −40 mV no currents were detectable. A similar conductance was also activated by the introduction of IP3 into the intracellular solution, suggesting that IP3 generation after surface IgM crosslinking is involved in the activation of this conductance. Both anti-μ and IP3 induced currents were blocked by 1 mM La+++, which is known to block Ca++ channels. These results strongly support the presence of membrane Ca++ channels in human B cells that function in the early stages of activation. Changes in transmembrane potential appear to be important in regulating Ca++ influx. These mechanisms work in concert to regulate the level of [Ca++]i during the early phases of human B cell activation. © 1993 Wiley-Liss, Inc.
Characterizing the two-tier gnutella topology

Characterizing the properties of peer-to-peer (P2P) overlay topologies in file-sharing applications is essential for understanding their impact on the network, identifying their performance bottlenecks in practice, and evaluating their performance via simulation. Such characterization requires accurate snapshots of the overlay topology which is difficult to capture due to the large size and dynamic nature. Previous studies characterizing overlay topologies not only are outdated but also rely on partial or potentially distorted snapshots. In this extended abstract, we briefly present the first characterization of two-tier Gnutella topologies based on recent and accurate snapshots.
The dilemma of biotechnology

The 1988 decision by the U.S. Health Care Financing Administration (HCFA) not to accord special reimbursement treatment to Genentech's tissue plasminogen activator (Activase™) was a signal event in the growing dilemma of biotechnology. In the U.S. (and to a degree in Japan and major Western European nations as well), therapeutic biotechnology investment appears to be on a collision course with health care cost containment efforts. During this time of renewed political interest in pharmaceutical pricing, there is urgent need for dialogue among the affected parties. Otherwise, repercussions of a collision could damage both private and public sector biotechnology innovation. The purpose of this article is to outline the nature of, and clarify the reasons for, the dilemma of biotechnology. ©1993 Wiley-Liss, Inc.
Expression, Site-Directed Mutagenesis, and Steady State Kinetic Analysis of the Terminal Thioesterase Domain of the Methymycin/Picromycin Polyketide Synthase†

The thioesterase (TE) domain of the methymycin/picromycin synthase (PICS) was functionally expressed in Escherichia coli, and the optimal N-terminal boundary of the recombinant TE was determined. A series of diketide-N-acetylcysteamine (SNAC) thioesters were tested as substrates. PICS TE showed a strong preference for the 2-methyl-3-ketopentanoyl-SNAC substrate 5 over the stereoisomers of the reduced diketides 1−4, with an ∼1.6:1 preference for the (2R,3S)-2-methyl-3-hydroxy diastereomer 2 over the (2S,3R)-diketide 1. The closely related DEBS TE, the thioesterase from the 6-deoxyerythronolide B synthase, showed a more marked 4.4:1 preference for 2 over 1, with only a slightly greater preference for the 3-ketoacyl-SNAC substrate 5. The roles of several active site residues in PICS TE were examined by site-directed mutagenesis. Serine 148, which is part of the apparent catalytic triad consisting of S148, H268, and D176, was found to be essential for thioesterase activity, while replacement of D176 with aspa...
Solid-state electronic conductivity of ruthenium nanoparticles passivated by metal–carbon covalent bonds

Abstract Stable ruthenium nanoparticles were prepared by passivation of the metal cores (diameter 2.7–3.2 nm by transmission electron microscopy) with ruthenium–carbon covalent bonds. Electrochemical study showed that the electronic conductivity of the particle films exhibited metal-like temperature dependence, and it decayed exponentially with the length of the alkyl spacer of the aliphatic protecting ligands, with an electronic coupling coefficient (β) of 0.48 A−1. This was ascribed to the strong Ru–C bonding interaction and low interfacial contact resistance where the spilling of core electrons into the organic protecting shell led to enhanced interparticle charge transfer.
Identifying Rate‐Controlling Enzymes in Metabolic Pathways without Kinetic Parameters

The flux control coefficients, originally defined by Kacser and Burns, provide a sound theoretical basis for identifying rate-controlling enzymes in metabolic pathways. However, the calculation of these quantities requires kinetic parameters, which are usually unavailable in practical systems. This article presents a method for evaluating the flux control coefficients by using measurements of metabolite concentrations in a transient state. The basis of this approach is the relationship identified here between transient fluxes and the flux control coefficients. Principal component analysis in the form of singular value decomposition is used to identify such relationships and evaluate the flux control coefficients. The approach does not require kinetic parameters and depends only on the knowledge of pathway stoichiometry, which is generally available.
A note on the ultrasonic attenuation near the magnetic critical points

Abstract Possible effects of spin-lattice relaxation and spin thermal conduction on ultrasonic attenuation are considered.