cssi/SciSciGPT-SciSciNet huggingface dataset:
Trajectory scaling function for bifurcations in four-dimensional symplectic maps

The trajectory scaling function for period-doubling bifurcations in four-dimensional symplectic maps is developed. It is a local basis expansion of the nearest-neighbor vectors of the (n+1)-times-bifurcated orbit in terms of the nth. It provides a complete description of the orbits on the way to infinite period doubling. As an application, the scaling function is used to predict the spectrum of singularities.
Effects of percutaneous electrical stimulation on functional ability, plasma creatine kinase, and pectoralis musculature of normal and genetically dystrophic chickens

Abstract The breast musculature of genetically dystrophic Line 413 and genetically related normal Line 412 chickens were treated in three separate trials with high-frequency electrical stimulation (ES). Beginning on days 7 or 14 ex ovo, each bird received three ES treatments per week. Each stimulation cycle repeated five times per day consisted of 15 s “on” followed by 50 s “off.” In the third trial only, the birds were additionally treated beginning day 3 ex ovo with either leucine (100 mg/kg) or the proteinase inhibitor Ep475 (10 mg/kg). ES significantly delayed the onset of righting disability in the dystrophic chickens. However, this improvement was temporary and could be masked by single treatments of either leucine or Ep475. Plasma creatine kinase activities were increased generally in both the stimulated normal and dystrophic birds. In two trials ES increased the relative muscle mass, and in one trial increased protein. ES had little effect on normal muscle mass or protein. However, ES treatment together with either leucine or Ep475 appeared to improve both normal and dystrophic muscle mass and protein. Furthermore ES decreased dystrophic muscle calcium but not acetylcholinesterase activity. On the other hand, ES had no effect on the total normal muscle calcium but increased normal acetylcholinesterase values. In both normal and dystrophic muscle samples, ES treatment in combination with leucine appeared to increase the mean muscle fiber diameters and number of myonuclei, and in the case of the dystrophic muscle, appeared to decrease the relative proportion of vacuolated, degenerating, and intensely oxidative histochemical fibers. In general, stimulation (especially in combination with leucine) appears to alter in varying degrees the phenotypic expression of the muscle disease exhibited in the dystrophic chicken.
Making Reference Service Count: Collecting and Using Reference Service Statistics to Make a Difference

This article describes an online system to collect, store, analyze, and report reference statistics. Information is entered at the point of service in a Web-based interface located on the computer desktop of each librarian. When record keeping and reporting processes were customized, automated, and made accessible to librarians, the data collected proved invaluable in tracking trends in reference service, monitoring library initiatives, and providing reference librarians information for analyzing and assessing their professional activity.
A comparison of the catalytic properties of cellobiose:quinone oxidoreductase and cellobiose oxidase from Phanerochaete chrysosporium

Several catalytic properties of the FAD enzyme cellobiose:quinone oxidoreductase (CBQ) and the heme/FAD enzyme, cellobiose oxidase (CBO) have been investigated and compared. Dichlorophenolindophenol was found to be a very good electron acceptor for cellobiose oxidation by both enzymes. The optimal pH value for this oxidation with dichlorophenol-indophenol as a co-substrate was observed around pH 4 for both enzymes. The turnover numbers of this reaction were also very similar. The Km values for cellobiose oxidation were identical, whereas the Km for CBO with dichlorophenol-indophenol is lower than that of CBQ. Atmospheric oxygen is a very poor electron acceptor for both CBO and CBQ, however, CBO can utilize cytochrome c as an effective electron acceptor, while CBQ cannot. The specific activity of CBO for cytochrome c is thus about 200-times higher than for oxygen. Thus, one way to distinguish the two enzymes is by the cytochrome-c-reducing ability of CBO. Therefore, we propose that the nomenclature for CBO is tentatively changed to cellobiose:cytochrome c oxidoreductase until a rational name can be installed. Both enzymes have radical-reducing activities. The cation radical, derived from 1,2,4,5-tetramethoxybenzene, was reduced by both enzymes at almost the same reaction rate. The phenoxyradical produced by lignin peroxidase, catalyzing the oxidation of acetosyringon, was also reduced by both enzymes. The reduction of phenoxyradicals formed by phenoloxidases (lignin peroxidases, as well as laccases) may be important in preventing repolymerization reactions which we suggest would significantly facilitate lignin degradation.
Resonance Raman evidence for Fe(IV) in compound II of horseradish peroxidase

Abstract Resonance Raman spectra have been obtained for Compound II of horseradish peroxidase. Its prophyrin vibrational frequencies are consistent with a planar low-spin heme containing Fe(IV). The oxidation-state marker band is found at the unprecedentedly high value of 1382 cm−1. This band was also observed in solutions of myoglobin and cytochrome c peroxidase to which H2O2 had been added. No evidence was found for an actual FeO double bond in Compound II.
3D distance-weighted Wiener filter for Poisson noise reduction in sinogram space for SPECT imaging

A three-dimensional (3D) distance-weighted Wiener filtering, which takes the characteristics of Poisson noise into account as well as the frequency-distance relationship of projection data, is described and evaluated. The task of spatial filtering on Poisson noise can be greatly simplified without the estimation of noise-power spectrum by first applying the Anscombe transformation to the projection data, which converts Poisson distributed noise into Gaussian distributed one with constant variance. By extending the stationary-phase condition and frequency-distance relationship (derived from the noise-free 2D sinogram) into 3D situation, we obtain a weighting function in frequency domain which is only dependent on the distance of an interested point source from the object center. Since the Anscombe transformation only changes the distribution of projection data, not the pixel location, a distance-variant weighting window for the Anscombe transformed data is derived and incorporated into the Wiener filter. Considering the regions with higher signal-to-noise ratio (SNR) receive greater weight in the estimation of signal-power spectrum, the proposed filter optimizes the data used to estimate the power spectrum of observed data and thus produces a better spatial resolution. Simulation and experimental results show improved noise reduction, especially in the peripheral regions, as compared with conventional filtering methods.
Susceptibility and risk: an overview

This symposium on susceptibility and risk was the third in a series designed to bring together experts from diverse disciplines to discuss contemporary issues in risk assessment. The topic in 1996 was especially challenging since susceptibility is influenced by a myriad of factors including environmental, genetic, social and political elements. The delineation of the relative contribution of various `susceptibility' factors has major implications for risk management options that may be applied in a regulatory context (risk prevention and risk reduction) or by the individual (risk avoidance). Current approaches to account for susceptibility in risk assessments (e.g. application of an uncertainty factor) have frequently been challenged as to their scientific basis and thus need periodic re-examination or update to maintain a credible foundation for the assessment process. The goal of this symposium was to gain a better understanding of the dimensions of the problem and to explore the directions that the risk assessment process might follow to better quantify the contribution of susceptibility in risk calculations.
3802 Pancreatic duct leaks: results of endoscopic management.

Pancreatic duct leak (PL) is a complication of acute or chronic pancreatitis or pancreatic trauma. Surgical therapy(Rx) has been the traditional Rx for PLs that fail to resolve with medical Rx. Recent reports support a role for endoscopic therapy (ERx). We report the result of ERx in pts with PL. Methods: From 4/94 to 10/99, 153 pts (91 men, 62 women) mean age 51 yrs (range 9-89) were found to have PL at ERP. According to ERP finding, pts were categorized as 1) complete pancreatic duct disruptions (CPDD)-Main PD disruption without visualization or wire passage into upstream duct 2) partial main pancreatic duct disruption (PPDD)- Main PD visualized upstream from PL and 3)small duct leak (SD)-Leak from side branch. ERx included endoscopic sphincterotomy (ES), pancreatic duct stricture dilation if needed, and pancreatic stent or nasopancreatic catheter (NPC) placement. Pts with an associated accessible pseudocyst had endoscopic drainage by a transpapillary, transmural, or combined approach. Longterm follow-up was obtained by CT, ERP, clinical evaluation, and phone calls. Results: See table. Summary: 1) ERx of PL was successful in 102/121 (84%) pts with a recurrence rate of 4%. 2) pts with PPDD (98%) or SD (100%) were more likely to seal than pts with complete disruptions (62%, p
The DETECT™ System: portable, reduced-length neuropsychological testing for mild traumatic brain injury via a novel immersive environment

Undiagnosed mild traumatic brain injury (mTBI) often leads to poor patient management and significant morbidity. The lack of an efficient screening tool is especially apparent in the athletic setti...
Development of a high-throughput methodology for screening coking resistance of modified thin-film catalysts.

A high-throughput optical technique has been developed for the rapid screening of coking resistant composition-spread promoted-catalyst libraries during hydrocarbon cracking, in particular for Jet Propellant 8(JP-8) cracking. The libraries are screened by measuring changes in the catalyst’s surface color due to the accumulation and burnoff of coke from the surface during JP-8 exposure and catalyst regeneration via oxygen burnoff. This rapid screening method was validated through a comparison of the coking properties of high-surface area powder cracking catalysts, and sputter deposited samples. Experiments on bimetallic (Pt–Gd) catalysts showed systematic trends consistently illustrating the superiority of Pt–Gd alloys to coking due to the presence of gadolinium.
Identification of major proton fluence events from nitrates in polar ice cores

Large transient concentrations of nitrates in polar ice cores have been identified as the signature of some major solar proton fluence events between 1940 and 1991. We review this solar proton proxy identification technique using nitrate concentration measurements in ice cores from the Arctic and Antarctic. Using this identification technique we go back in time in an attempt to identify major solar proton events during the past several centuries. There is a very large nitrate increase corresponding to the Carrington flare of 1859 evident in the Arctic ice core. Other significant nitrate increases may indicate that major solar proton events occurred toward the end of the last century. The problems associated with this new technique of using nitrates as proxies to identify solar proton events are discussed.
Effect of subgrid cloud‐radiation interaction on climate simulations

[1] The mosaic representation of subgrid cloud-radiation interaction is implemented in the radiation scheme of the NCAR Community Climate Model version 3 (CCM3) to investigate its impacts on global climate simulations. It is found that the CCM3 with the modified radiation scheme enables the use of more realistic cloud amounts as well as cloud water contents while producing net radiative fluxes closer to observations. The improved vertical distribution of cloud water path based on the cloud-resolving model (CRM) simulations increases the radiative heating in the upper troposphere over the tropics, which reduces the long-standing cold bias in the temperature field. Consequently, not only the representation of cloud-radiation interactions is more physically consistent and accurate, but also the climate simulations are significantly affected and improved.
Technology parks in a developing country: the case of India

Following the economic liberalization of 1991, the government of India established the software technology parks of India (STPI) scheme and opened numerous software parks around the country. These parks have played a critical role in the growth of India’s software sector. In recent years, private software parks have also been established in different parts of India. The government of India is now promoting biotechnology (biotech) parks to encourage growth of this emerging sector. The biotech parks are still in their infancy with a few operating parks. There are several upcoming biotech parks in different Indian states with support from the respective state governments. The government of India continues to play an important role in establishing technology parks. Biotech-Information Technology (Bio-IT) park is the next type of park that the government is planning to promote. This article discusses the institutional history of these technology parks in India.
Adjunctive rheolytic thrombectomy for central venous sinus thrombosis: technical case report.

OBJECTIVE: Patients with dural sinus thrombosis occasionally present with a malignant clinical course marked by parenchymal hemorrhage accompanied by either a severe neurological deficit or a persistent deterioration on therapeutic levels of antithrombotic medications. This scenario precludes traditional revascularization strategies with direct fibrinolytic infusion because of the risk of exacerbating the preexisting cerebral hemorrhage. In the current series, we describe our experience using the AngioJet (Possis Medical, Minneapolis, MN), a rheolytic mechanical thrombectomy device, in conjunction with systemic heparinization to achieve rapid sinus revascularization without fibrinolytic therapy. METHODS: A retrospective review of a prospectively maintained database identified four patients ranging in age from 28 to 67 years (three women, one man) with cerebral venous thrombosis and rapidly deteriorating levels of consciousness who underwent transfemoral intravenous rheolytic thrombectomy using the Angiojet XMI and/or Xpeedior catheters (Possis Medical). The imaging features, treatment specifications, and disease outcome were reviewed. RESULTS: All four patients underwent successful mechanical thrombectomy as indicated by restoration of blood flow through the affected sinuses. Three of the four patients demonstrated normalization of angiographic transit time after thrombectomy. In these three patients, rapid neurological improvement ensued. The fourth patient died during the periprocedural period. No procedural complications were encountered. CONCLUSION: Systemic heparinizafion with adjunctive rheolytic thrombectomy (without fibrinolytic therapy) is a safe and effective treatment strategy for selected patients with dural venous sinus thrombosis.
dGTP Starvation in Escherichia coli Provides New Insights into the Thymineless-Death Phenomenon

Starvation of cells for the DNA building block dTTP is strikingly lethal (thymineless death, TLD), and this effect is observed in all organisms. The phenomenon, discovered some 60 years ago, is widely used to kill cells in anticancer therapies, but many questions regarding the precise underlying mechanisms have remained. Here, we show for the first time that starvation for the DNA precursor dGTP can kill E. coli cells in a manner sharing many features with TLD. dGTP starvation is accomplished by combining up-regulation of a cellular dGTPase with a deficiency of the guanine salvage enzyme guanine-(hypoxanthine)-phosphoribosyltransferase. These cells, when grown in medium without an exogenous purine source like hypoxanthine or adenine, display a specific collapse of the dGTP pool, slow-down of chromosomal replication, the generation of multi-branched nucleoids, induction of the SOS system, and cell death. We conclude that starvation for a single DNA building block is sufficient to bring about cell death.
Purification of the i-antigen 51A fromParamecium tetraurelia by immunoaffinity chromatography

Abstract Purification of the surface antigen of Paramecium tetraurelia (termed i-antigen) by previously published procedures has been shown to result in preparations which frequently contain contaminating proteins including a thiol-activated protease. Alternate procedures for the purification of i-antigen were developed using ion-exchange chromatography. While certain of these procedures result in a homogeneous preparation of i-antigen, the poor yields obtained make these procedures impractical. An alternate method for the purification of i-antigen was developed using immunoaffinity chromatography. Purification by this technique proved to be superior to the various standard procedures described previously. The immunoaffinity column is rapid and results in a recovery, on the average, of over 95% of the applied material. The columns are readily regenerated and may be used numerous times without loss of capacity or purification ability. The i-antigen purified by this method appears homogeneous immunologically and electrophoretically on polyacrylamide gel electrophoresis and isoelectric focusing.
ESD protection methods in Ethernet based embedded systems

Electrostatic discharge can happen anytime a charged conductive object approaches another conductive object. A strong electric field forms between the objects which can cause field induced breakdown. When the voltage between the objects exceed the breakdown voltage of the air and the insulation between them, an arc occurs. The current in this arc can reach tens of amps in a few nanoseconds which may cause damage or loss of functionality to susceptible devices. One of the major problems in ESD immunity design is identification of coupling paths. This paper shows a few ways of identifying the coupling paths and outlines some methods of suppressing them or avoiding them. The case study considered here is an Ethernet based embedded system.
Review of the theory of amorphous semiconductors

Abstract The existing simple models of the electronic structure of disordered materials are reviewed. The focus is on the universal features of these models and their consequences for amorphous semiconductors. Simple plausibility arguments are given showing that continuous bands of extended states with tails of localized states associated with fluctuations within the disordered material can always be expected. Models for the mobility in which shoulders occur at the energies of transition from localized to extended states are reviewed. It is a mobility gap rather than a gap in the density of states which is responsible for the activated temperature dependence of the conductivity in amorphous semiconductors. Hopping conduction and the nature of the electronic motion in extended states near the mobility edges is discussed. The latter is likened to Brownian motion within certain limitations. Finally, the Anderson transition is discussed within the present models.
Optical Spectra of Fe(II) Cytochrome c Interpreted Using Molecular Dynamics Simulations and Quantum Mechanical Calculations

Porphyrin electronic transitions in heme proteins provide a useful tool for probing the protein environment, since the surrounding protein affects the porphyrin π-electron cloud. Perturbations can arise from structural distortions of the porphyrin ring, from the internal electric field generated by charged and polar groups, or from axial ligation to the heme iron. In this work, cytochrome c in aqueous solution or in glasses of trehalose or glycerol/water was examined as a function of temperature to evaluate the effect of fluctuations on the heme. The amide I band of cytochrome c in trehalose remains constant over a wide temperature excursion, indicating that interactions between the protein and the matrix do not change with temperature. The width of the Q(0,0) optical transition measured at low temperature (i.e., <100 K) reflects the temperature at which the glass was formed, while the temperature profiles of the widths for the protein in different solvents and glasses are similar at high temperature. The...
Optimization of radiative-convective arrays of pin fins including mutual irradiation between fins

Abstract This study investigates the optimal pin fin array of variable cross section for a given fin material per unit base area. The effects of conduction, convection and radiation heat transfer is studied including the mutual irradiation between a fin and all other fins and the base. The finite difference method is used to solve the resulting nonlinear-integral differential equations. The effect of parameters such as fin spacing, profile, and emissivity on the fin array effectiveness is studied and the results are presented in a graphical form convenient for parametric study and design analysis.
Tailored strategies for radiation therapy in classical Hodgkin's lymphoma

Radiotherapeutic advances have contributed to the evolution of Hodgkin's lymphoma (HL) treatment paradigms. A reduction in radiation therapy (RT) field size and dose has the potential to significantly impact the therapeutic ratio by diminishing late toxicities while maintaining curability. Substantial progress in risk stratification has contributed to the development of tailored RT strategies which address both field design as well as dose. Technologic improvements have also enhanced the ability to adapt the RT technique to the individual patient. The refinement of the RT approach and its incorporation into current combined modality strategies in adult classical HL is the subject of ongoing investigation and is critically reviewed.
Textures in narrow cylinders in superfluid 3He-A

We calculate the equilibrium configurations of three textures in a narrow cylinder in the presence of superflow along the cylinder axis. The Mermin-Ho texture is shown to be unstable against a small twist in the dipole-free limit even in the absence of superflow. The radial disgyration undergoes a second-order transition forqR ∼-3.31, while the circular disgyration gives rise to a helical texture forpR ≳ 3.5, whereR is the radius of the cylinder andq [≡ (2m/ħ)V s]andp are momenta associated with superflow. The associated nuclear magnetic resonance frequencies are determined.
Adolescents' preference for technology-based emergency department behavioral interventions: does it depend on risky behaviors?

OBJECTIVES: This study aimed to (1) determine the prevalence of technology use and interest in technology-based interventions among adolescent emergency department patients and (2) examine the association between interest in an intervention and self-reported risky behaviors. METHODS: Adolescents (age, 13-17 years) presenting to an urban pediatric emergency department completed a survey regarding baseline technology use, risky behaviors, and interest in and preferred format for behavioral health interventions. Questions were drawn from validated measures when possible. Descriptive statistics and χ tests were calculated to identify whether self-reported risky behaviors were differentially associated with intervention preference. RESULTS: Two hundred thirty-four patients (81.8% of eligible) consented to participate. Almost all used technology, including computers (98.7%), social networking (84.9%), and text messaging (95.1%). Adolescents reported high prevalence of risky behaviors as follows: unintentional injury (93.2%), peer violence exposure (29.3%), dating violence victimization (23.0%), depression or anxiety (30.0%), alcohol use (22.8%), drug use (36.1%), cigarette use (16.4%), and risky sexual behaviors (15.1%). Most were interested in receiving behavioral interventions (ranging from 93.6% interest in unintentional injury prevention, to 73.1% in smoking cessation); 45% to 93% preferred technology-based (vs in person, telephone call, or paper) interventions for each topic. Proportion interested in a specific topic and proportion preferring a technology-based intervention did not significantly differ by self-reported risky behaviors. CONCLUSIONS: Among this sample of adolescent emergency department patients, high rates of multiple risky behaviors are reported. Patients endorsed interest in receiving interventions for these behaviors, regardless of whether they reported the behavior. Most used multiple forms of technology, and approximately 50% preferred a technology-based intervention format. Language: en
Mechanisms governing deformation and damage during elevated-temperature fatigue of an aluminum-magnesium-silicon alloy

The cyclic deformation and fracture characteristics of aluminum alloy 6061 are presented and discussed. The specimens were cyclically deformed using fully reversed tension-compression loading under total strain-amplitude control, over a range of temperatures. The alloy showed evidence of softening to failure at all test temperatures. The degree of softening during fully reversed deformation increased with test temperature. The presence of shearable matrix precipitates results in a microstructure that offers a local decrease in resistance to dislocation movement, causing a progressive loss of strengthening contributions to the matrix. At elevated temperatures, localized oxidation and embrittlement at the grain boundaries are exacerbated by the applied cyclic stress and play an important role in accelerating crack initiation and subsequent crack propagation. The fracture behavior of the alloy is discussed in light of competing influences of intrinsic microstructural effects, deformation characteristics arising from a combination of mechanical and microstructural contributions, cyclic plastic strain amplitude and concomitant response stress, and the test temperature.
Transfer versus transition: success in pediatric transplantation brings the welcome challenge of transition.

Context—Increasing success with solid organ transplantation in children has increased the numbers of adolescents and young adults who are at an age to transfer to adult healthcare.Objective—To determine the nature of transfer/transition of adolescents and young adults to adult healthcare.Design—Using a qualitative approach, 24 young adults provided answers to 12 questions about their transfer to adult healthcare. Responses were compared to identify themes.Setting—Subjects had been pediatric patients at Children's Hospital of Pittsburgh. Most were transferred to the University of Pittsburgh Medical Center.Patients—The subjects had received, or were on the list to receive, solid organ transplants and had been transferred within 18 months of the study.Results—Twenty-four of 37 potential subjects completed interviews. Those who participated were enthusiastic about making a contribution to the transfer process. Most subjects cited difficulty leaving the pediatric system. Challenges included abrupt transfers, i...
Piloting Tailored Teaching on Nonpharmacologic Enhancements for Postoperative Pain Management in Older Adults

Despite many advances in the pharmacologic treatment of pain, the issue of unresolved postoperative pain continues to plague patients and health care professionals. Little seems to be known about the reasons why nonpharmacologic methods are not more widely used, particularly as they are commonly low in cost, easy to use, and largely free of adverse side effects. A central question has to do with what patients are taught about nonpharmacologic methods and how a novel mode of teaching can be embedded in practice. A seven-step pre-posttest teaching intervention pilot study was deployed with older joint replacement patients within the context of a translational research model. Results of the teaching pilot showed significant post-teaching changes in subjects' knowledge and attitudes about nonpharmacologic methods for pain management, high satisfaction with the nonpharmacologic methods they chose, and incrementally greater use of the nonpharmacologic methods over the course of the hospital stay. A randomized controlled trial of the study is now in the early planning stages in an effort to obtain generalizable results that will help solidify evidence of the impact of music, imagery, and slow-stroke massage on pain management and confirm the value of patient teaching as an important means of offering patients more options for managing their own pain.
Improving competitive intelligence for knowledge management systems

Knowledge management encompasses the entire intelligence cycle from planning to reporting. One aspect that is often overlooked or minimised is the inclusion of competitive intelligence. This paper proposes a new concept to fine-tune the process of electronically gathering competitive intelligence – a key activity in knowledge management systems. Most tools are nondiscriminatory in information gathering, and a structured approach is needed to assist managers at all organisational levels in the needs identification process. The proposed multiclass interest profile provides the capability of expanding the coverage of critical intelligence areas to reflect the assorted topics that make up an organisation's information needs. Each component is customisable to make the information that is gathered pertinent to the organisation, and supporting features such as profile expansion and fine-tuning are also incorporated.
Heterojunction solar cells of SnO2/Si

Heterojunction solar cells (HJSC’s), fabricated by electron beam evaportaion of SnO2 films onto monocrystalline and polycrystalline Si substrates, show conversion efficiencies as high as 9.9%, fill factors of 0.64, and open circuit voltages of 525 mV under AMI simulated irradiation. The SnO2, an n-type semiconductor, acts as a transparent window to solar irradiation and as an antireflection coating of the Si, and it provides the band bending in the Si necessary for photovoltaic conversion. The SnO2 films, nominally 50 nm thick, have conductivities of the order of 103(Ω-cm)−1 so that the film makes a good electrical contact between the junction and the metallic front contacts. Measurements of C−2-V and I-V characteristics are consistent with heterojunction theory, and the data imply an electron affinity of the SnO2 of approximately 0.8 eV greater than the electron affinity of Si. This value limits the open circuit voltage of HJSC’s made on p-type substrates to values too small for useful photovoltaic conversion. The predominant dark current mechanism of units of n-type substrates at room temperature and forward bias in the range of 0.3−0.5 V is electron-hole recombination in the transition region. The experimentally determined activation energy is 0.51 eV, approximately Eg/2. At forward voltages below 0.3 V, multistep tunneling via interband states predominates. The photocurrent apparently depends on interface states through which the photogenerated holes in the Si recombine with electrons in the SnO2.
Improving Healthcare Environmental Cleaning and Disinfection: Current and Evolving Issues

Affiliations: 1. Infectious Diseases Section, Carney Hospital and Boston University School of Medicine, Boston, Massachusetts; 2. Division of Infectious Diseases and Health Policy Research Institute, University of California, Irvine, School of Medicine, Irvine, California. Received January 8, 2013; accepted January 11, 2013; electronically published April 9, 2013. 2013 by The Society for Healthcare Epidemiology of America. All rights reserved. 0899-823X/2013/3405-0010$15.00. DOI: 10.1086/670222 Over the past several years, there has been a growing recognition that contamination of the patient environment by all bacterial and viral pathogens frequently associated with healthcare-associated infections (HAIs) occurs in wide range of healthcare settings. In the past decade, increasing evidence has emerged to highlight lapses in procedures for and quality of healthcare cleaning and disinfection despite the presence of institutional policies consistent with national guidance. Visual assessment was seen as the gold standard for monitoring the quality of cleaning by environmental services (EVS) workers until several studies consistently demonstrated that residual pathogens were present on patient care surfaces after routine cleaning and that methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) could be transmitted to patients from prior room occupants despite terminal cleaning with high-compliance visual inspection. In addition, the presence of orphan items—mobile healthcare equipment where ownership of cleaning and disinfection is unclear, such as glucometers, intravenous poles, bar-coding scanners, and computers on wheels—highlights further vulnerabilities in adequate cleaning of patient care areas. As summarized in Table 1, multiple studies have clarified key factors that define both our basic understanding of the transmission of healthcare-associated pathogens from environmental surfaces in patient care areas to susceptible patients and the challenges related to optimizing the adequacy of disinfection cleaning for infection prevention. As our understanding of the critical factors in environmental cleaning and disinfection improves (Table 1), it is important to assess the challenges found in our current approach to disinfection cleaning interventions and to identify necessary leading-edge research opportunities that will define best practices in environmental cleaning across the spectrum of healthcare settings. current issues in healthcare environmental cleaning and disinfection
Free field analysis considerations for dynamic soil-structure interaction

Abstract The effects of free field motion computation procedures on the response of soil-structure interaction systems is examined by employing the finite element method. The results indicate that under certain conditions the analyst should provide specific boundary conditions in order to preserve the free field motion character. In the event that such steps are not taken one should expect significant differences in the computed structural motions.
The Drosophila Smad cofactor Schnurri engages in redundant and synergistic interactions with multiple corepressors.

In Drosophila a large zinc finger protein, Schnurri, functions as a Smad cofactor required for repression of brinker and other negative targets in response to signaling by the transforming growth factor β ligand, Decapentaplegic. Schnurri binds to the silencer-bound Smads through a cluster of zinc fingers located near its carboxy-terminus and silences via a separate repression domain adjacent to this zinc-finger cluster. Here we show that this repression domain functions through interaction with two corepressors, dCtBP and dSin3A, and that either interaction is sufficient for repression. We also report that Schnurri contains additional repression domains that function through interaction with dCtBP, Groucho, dSin3A and SMRTER. By testing for the ability to rescue a shn RNAi phenotype we provide evidence that these diverse repression domains are both cooperative and partially redundant. In addition we find that Shn harbors a region capable of transcriptional activation, consistent with evidence that Schnurri can function as an activator as well as a repressor.
Morphological investigations of submarine volcanism: Henderson Seamount

New, high-quality bathymetric data for Henderson Seamount (about 80 km west of the southern tip of Baja California) reveal complexities of structure that allow comparison with subaerial volcanoes. Henderson is 3.3 km high, with a basal diameter of 33 km, resembling a subaerial shield volcano in gross morphology. The summit is composed of alkali basalts. There is no summit caldera, but a large subcircular depression on the volcano9s eastern flank may reflect a trapdoor caldera similar to those of the Canary Island volcanoes, or it may be a large landslide scar. Smaller cones around the base of the central volcano appear to be formed by two different processes, perhaps related to different rates of basaltic extrusion. One cone appears to be topped by a large crater. Morphologically, this structure resembles subaerial cinder cones; thus, its existence suggests that explosive volcanism of the type that forms cinder cones subaerially may occur at abyssal depths.
Stimulation of cell division by membrane-active agents

Abstract Agents that decrease membrane stability (e.g. dimethyl sulfoxide, lysolecithin, sodium oleate, and short-chain alcohols) stimulate multinucleoid, serpentine filaments of Agmenellum quadruplicatum strains SN12 and SN29 to divide into cellular equivalents within approximately one generation time. Agents that increase membrane stability (e.g. long-chain alcohols) antagonize this timulation. Thus, the physical properties of the cell membrane appear to be involved in the regulation of cell division. These observations suggest that the invagination of the cell wall may be regulated by agents that interact with the plasma membrane and with enzymes involved in peptidoglycan synthesis.
Phase-sensitive bichromatic photoresistance in a two-dimensional electron gas

We have studied microwave photoresistance in a two-dimensional electron system subject to two radiation fields (frequencies ${\ensuremath{\omega}}_{1}$ and ${\ensuremath{\omega}}_{2}$) using quantum kinetic equation. We have found that when ${\ensuremath{\omega}}_{2}/{\ensuremath{\omega}}_{1}=1+2/N$, where $N$ is an integer, and both waves have the same polarization, the displacement mechanism gives rise to a new, phase-sensitive photoresistance. This photoresistance oscillates with the magnetic field and can be a good fraction of the total photoresistance under typical experimental conditions. The inelastic mechanism, on the other hand, gives zero phase-sensitive photoresistance if the radiation fields are circularly polarized.
Deposition of conformal copper and nickel films from supercritical carbon dioxide.

Device-quality copper and nickel films were deposited onto planar and etched silicon substrates by the reduction of soluble organometallic compounds with hydrogen in a supercritical carbon dioxide solution. Exceptional step coverage on complex surfaces and complete filling of high-aspect-ratio features of less than 100 nanometers width were achieved. Nickel was deposited at 60°C by the reduction of bis(cyclopentadienyl)nickel and copper was deposited from either copper(I) or copper(II) compounds onto the native oxide of silicon or metal nitrides with seed layers at temperatures up to 200°C and directly on each surface at temperatures above 250°C. The latter approach provides a single-step means for achieving high-aspect-ratio feature fill necessary for copper interconnect structures in future generations of integrated circuits.
Respiratory and behavioral responses of the grass shrimp Palaemonetes pugio to cadmium and reduced dissolved oxygen

Adult grass shrimp (Palaemonetes pugio) were collected during July and August, 1973, and exposed for 48-h periods to a series of sublethal cadmium (Cd) concentrations: 0.1 and 0.56 mg l-1 for metabolic studies; and 0.01, 0.05, 0.1, 0.3, 0.56 mg l-1 for locomotor studies. Treatment effects were tested singly and in combination at selected dissolved oxygen (DO) concentrations ranging from near saturation to 0.8 mgl-1. Shrimp not exposed to Cd exhibited metabolic regulation between 6.5 and, 4.6 mg DOl-1, with progressively lower O2 consumption rates at lower DO concentrations. Oxygen consumption of Cd-exposed shrimp was suppressed overall relative to the non-Cd treated shrimp, and with one exception, the magnitude of metabolic suppression directly corresponded to Cd concentration. Locomotor activity of non-Cd exposed shrimp was relatively independent of DO concentration down to 2.8 mg DO l-1 and became significantly suppressed at 1.8 mg DO l-1 and below. Significant suppression of locomotion was evident in shrimp exposed to 0.56 mg Cd l-1, but was not seen in treatment groups of 0.3 mg Cd l-1 or lower. No interaction on locomotor activity of shrimp was detected between Cd exposure and oxygen concentration. The reduction of locomotor activity and metabolism at 0.56 mg Cd l-1 exposure is similar to that occurring under reduced oxygen condition. It is hypothesized that Cd acts in some manner to suppress O2 availability to P. pugio, a suggestion consistent with literature reports on adverse effects of Cd on fish respiratory enzymes and gill tissue.
Liquid rescheduling for the treatment of rumination

A pre-intervention assessment was conducted to determine the conditions under which rumination by a 19-year-old man with autism was most and least likely to occur. The results of the assessment suggested that rumination was least likely when the participant did not consume liquids with meals and when he consumed peanut butter during meals. Based upon the results of the assessment, an intervention consisting of rescheduling access to liquids (i.e., no liquids during meals) was evaluated across both breakfast and lunch at the participant's school placement. Results suggest that the intervention was effective in reducing rumination. Copyright © 2003 John Wiley & Sons, Ltd.
How does vibration reduce pain

Cutaneous vibration is able to reduce both clinical and experimental pain, an effect called vibratory analgesia. The traditional explanation for this phenomenon is that it is mediated by lateral inhibition at the segmental (spinal cord) level, in pain-coding cells with center-surround receptive fields. We evaluated this hypothesis by testing for two signs of lateral inhibition-namely (1) an effect of the distance between the noxious and vibratory stimuli and (2) an inhibition-induced shift in the perceived location of the noxious stimulus. The experiment involved continuous ratings of the pain from pressure applied to the back of a finger, alone and in the presence of vibration delivered to sites on the palm of the hand both near to and far from the site of painful stimulation. Neither prediction of the segmental hypothesis was supported. There was also little evidence to support the view (widely held by subjects) that distraction is the primary mechanism of vibratory analgesia. The results are more consistent with a recently proposed theory of interactions between two cortical areas that are primarily involved in coding pain and touch, respectively.
Using finite element tools in proving shift theorems for elliptic boundary value problems

We consider the Laplace equation under mixed boundary conditions on a polygonal domain Ω. Regularity estimates in terms of Sobolev norms of fractional order for this type of problem are proved. The analysis is based on new interpolation results and multilevel representation of norms on the Sobolev spaces Hα(Ω). The Fourier transform and the construction of extension operators to Sobolev spaces on ℝ2 are avoided in the proofs of the interpolation theorems. Copyright © 2002 John Wiley & Sons, Ltd.
Magnetic relaxation in spheromaks using spectral expansions in cylindrical geometry

Abstract. A code has been developed to study self-organization in spheromaks using the Galerkin method in which the magnetic and velocity fields appearing in the incompressible dissipative MHD equations are expanded in a spectrum of Chandrasekhar–Kendall eigenstates of the curl. The ultimate goal is to apply the Galerkin method in actual spheromak geometry to calculate turbulence levels and associated transport. The present work employs the straight-cylinder approximation, known to give a good representation of internal ideal MHD modes in spheromaks and applied here to resistive tearing modes. Our main result to date is a demonstration that the Galerkin method can exhibit tearing island formation with only a few states in the spectrum. Example quasilinear calculations are presented for a decaying spheromak and for a spheromak created by gun injection.
Soil acidification induced by elevated atmospheric CO2

Soil acidification is a very important process in the functioning of earth's ecosystems. A major source of soil acidity is CO2, derived from the respiration of plant roots and microbes, which forms carbonic acid in soil waters. Because elevated atmospheric CO2 often stimulates respiration of soil biota in experiments that test ecosystem effects of elevated atmospheric CO2, we hypothesize that rising atmospheric CO2 (which has increased from ∼200 ppm since the interglacial and may exceed 550 ppm by the end of the 21st century) is significantly increasing acid inputs to soils. Here, using column-leaching experiments with contrasting soils, we demonstrate that soil CO2 is a much more potent agent of soil acidification than is generally appreciated, capable of displacing almost all exchangeable base cations in soils, and even elevating Al(III) concentrations in H2CO3-acidified soil waters. The potent soil acidifying potential of soil H2CO3 is attributed to the low pKa,1 of molecular H2CO3 (3.76 at 25°C), which contrasts greatly with that of (a convention that combines CO2 (aq) and molecular H2CO3, the pKa,1 of which is 6.36 at 25°C). This distinction is significant for soil systems because of soil's greatly elevated CO2, their variety of sinks for H+, and the wide range of contact times between soil solids, water, and gas. Modelling suggests that a doubling of atmospheric CO2 may increase acid inputs from carbonic acid leaching by up to 50%. Combined with the results of CO2 studies in whole ecosystems, this implies that increases in atmospheric CO2 since the interglacial have gradually acidified soils, especially poorly buffered soils, throughout the world.
Characterisation of plasma in a rail gun

The mechanism of plasma and projectile acceleration in a DC rail gun is described from a microscopic point of view through the establishment of the Hall field. The plasma conductivity is shown to be a tensor, indicating that there is a small component of current parallel to the direction of acceleration. The plasma characteristics are evaluated in the experiment of Bauer et al. as a function of plasma mass through a simple fluid mechanical analysis of the plasma. By equating the energy dissipated in the plasma with the radiation heat loss, the properties of the plasma are determined.
A boundary surveillance strategy based on critical line in wireless sensor networks

Environment monitoring is an important class of wireless sensor networks applications. A traditional way for such applications is to deploy sensors all over a region and always aim to cover as more area as possible. However, this way is not only a great waste of money and recourses but also unnecessary and unrealistic. It also invokes many data collisions and brings serious burden to the network protocols. In this paper, we propose a critical line based environment surveillance strategy. We deploy sensors along critical lines instead of all over the region. Our aim is to capture or detect the target or target event rather than tracking it. As coverage is an important factor impacting monitoring, we study the boundary coverage capability under several conditions with consideration of different deploying methods of sensors. We also compare our surveillance strategy with the traditional way, and the results show that our strategy saves great amount of sensors in our strategy.