cssi/SciSciGPT-SciSciNet huggingface dataset:
The Potential for Self-Organizing Maps to Identify Model Error Structures

AbstractAn important aspect of numerical weather model improvement is the identification of deficient areas of the model, particularly deficiencies that are flow dependent or otherwise vary in time or space. Here the authors introduce the use of self-organizing maps (SOMs) and analysis increments from data assimilation to identify model deficiencies. Systematic increments reveal time- and space-dependent systematic errors, while SOMs provide a method for categorizing forecasts or increment patterns. The SOMs can be either used for direct analysis or used to produce composites of other fields. This study uses the forecasts and increments of 2-m temperature and dry column mass perturbation μ over a 4-week period to demonstrate the potential of this technique. Results demonstrate the potential of this technique for identifying spatially varying systematic model errors.
The uptake of 36C1 into astrocytes in tissue culture by a potassium-dependent, saturable process.

— Previous suggestions that the K+-dependent uptake of chloride by mammalian cerebral cortex is localized to cortical astrocytes has been investigated in two lines of neural cells in tissue culture. Hamster astrocytes and mouse neuroblastoma cells were each cultured on small glass cover slips in Eagle's (astrocytes) or Dulbecco's (neuroblastoma) supplemented media. At 48 h, cultures were incubated at 37°C for 1–60 min in the presence of 36Cl plus [3H]inulin (as a measure of extracellular space). In media containing approximately 140 mm chloride, the rate of uptake of 36Cl by the astrocytes was a function of the concentration of K+ (range 5–54 mm) in the medium, and the uptake was characterized by saturation kinetics and an apparent Km of 38·5 mm. The uptake was temperature and apparently energy dependent, significantly inhibited by 5 or 10 mm Br-, I-, SCN- or ClO4-, and competitively inhibited by 10 mm acetazolamide (Ki= 27·1 mm). None of these characteristics were observed with neuroblastoma cultures studied under similar conditions. In chloride-free media, the cellular K/Na ratio of the astrocytes shifted from the usual value of 4·55 to a value of 0·29, the culture medium became more alkaline than normal, and the cells spontaneously sloughed from the cover slips but remained normally viable. Our observations are the first to provide direct support for previous suggestions that there is a mediated, K+-dependent coupled cation, chloride and fluid uptake by mammalian cerebrocortical glia and that this uptake is an enzymatically catalysed process. The observations have been discussed in terms of a presumed central role for astrocytes in modulating the external ionic milieu of the neurons they surround and in terms of implications for epilepsy, stroke and cortical edema.
Approximate estimates for the surface pressure of mars based on infrared transmission data in the 2μ region

Abstract The surface pressure of Mars has been estimated on the basis of Kuiper's 1964 observations by utilizing a non-overlapping spectral-line model for the CO2 bands on Mars, with absorption determined by spectral lines lying in the square-root region of the curves of growth. Neglecting shielding by the opaque line centers in the atmosphere of the Earth, we obtain a lower bound for the Martian surface pressure (ps♂)min of 1·6 mbar. Introduction of approximate corrections for “nearly black” line centers yields a “best estimate” for ps♂ of 6·1 mbar; the uncertainty in this value is largely determined by unknown errors in the measurements and by lack of information concerning spectral line structure in the far line wings.
Evaluation of reconstructive techniques for anterior and middle skull base defects following tumor ablation.

Purpose Reconstruction after resection of head and neck cancer can be challenging, especially when tumors extend to the base of the skull. Vascularized flaps are the option of choice, whether free or pedicled. Free flaps have the added benefit of access to the more cephalad defects of the anterior cranial base without the constraints of the rotation arc of pedicled flaps. The authors compared various flaps used for the reconstruction of defects of the anterior or middle skull base after resection of malignant tumors. Materials and Methods The authors identified 12 patients in whom 14 flaps were performed. All patients had malignant neoplasms extending to the anterior or middle cranial base that were reconstructed with free or pedicled flaps. A retrospective analysis was performed to compare the characteristics of patient demographics, tumor, and surgical technique. Complications among the various flaps were compared. Patients' assessments of function and quality of life were assessed by conducting a telephone survey. Results Most patients had stage 3 or 4 squamous cell carcinoma originating in the paranasal sinuses and extending to the anterior or middle skull base, requiring orbital exenteration. The flaps used included 6 radial forearm free flaps (RFFFs), 3 anterolateral thigh flaps (ALTs), 4 thoracodorsal artery perforator free flaps (TDAPs), and 1 pedicled supraclavicular flap. There were no major complications, such as perioperative heart attack, stroke, death, or meningitis. Minor complications included 3 mesh exposures after radiation treatment, 1 wound infection, and 2 flaps with wound dehiscence after radiation. These 2 dehiscences were seen with RFFFs and were later reoperated using TDAPs. There were no cerebrospinal fluid leaks or donor-site morbidity. There were no complaints of functional deficits, such as feeding difficulties or speech impairments. Some visual disturbance was reported after orbital exenteration, although this was an expected outcome. Conclusions Vascularized flaps provide reliable and durable reconstructive options for anterior and middle skull base defects after resection of large complex malignant neoplasms of the craniofacial region. Free flaps, such as RFFFs, ALTs, and TDAPs, are well suited for these defects. They have a low risk of complications and low donor-site morbidity and offer good functional and esthetic outcomes.
Solid-state NMR studies of the crystalline and amorphous domains within PEO and PEO: LiTf systems

Solid polymer electrolytes (SPEs) contain amorphous and crystalline regions, each of which have unique contributions to the (13)C NMR spectrum. Understanding and assigning the (13)C NMR signals are vital to interpreting the NMR data collected for each phase. The (13)C CPMAS solid-state NMR spectrum of poly(ethylene oxide), a common polymer electrolyte host material, has superimposed broad and narrow components. Previously, the narrow component has been assigned to the amorphous region and the broad component to the crystalline PEO fraction. These assignments for pure PEO have been applied to various PEO:salt systems. Using lithium triflate salt dissolved in PEO, we revisit the spectral assignments and discover that the narrow component is due to crystalline PEO:LiTf component, which is reversed from the previous pure PEO assignment. This paradigm shift is based on data collected from a 100% crystalline PEO:LiTf with a 3:1 oxygen:lithium ratio sample, which exhibited only the narrow peak. For dilute electrolytes, such as 20:1 PEO:LiTf, the (13)C CPMAS spectra contain the narrow peak superimposed on a broad peak as seen with pure PEO. As dilute electrolytes are heterogeneous with crystalline and amorphous regions of both pure PEO and PEO:LiTf complex, peak assignments for pure PEO and PEO:LiTf are important. Thus, we reexamine the previous assignment for pure PEO using samples of pure powdered PEO, thermally treated pure powdered PEO, and a thin film PEO cast from an acetonitrile solution. With these different samples, we observed the growth of the narrow peak under conditions that favor crystallization. Therefore, for pure PEO, we have reassigned the narrow peak to the crystalline region and the broad peak to the amorphous region. In light of our observations, previous NMR studies of pure PEO and PEO SPEs should be reinvestigated. We also use rotational echo double resonance (REDOR) to study the 20:1 PEO:LiTf created from 2 and 100 kDa PEO. We find that the lithium environment is similar in the respective microcrystalline domains. However, the 100 kDa samples have a larger fraction of pure crystalline PEO.
Workforce needs for endovascular acute ischemic stroke therapy: myth or reality?

The acute ischemic strokes amenable to intraarterial therapy probably number no more than 20,000 per year in the United States. The future demand for intraarterial reperfusion techniques may change, but the fraction of patients who require intraarterial thrombolysis is currently rather low, and the number of neurointerventionists is adequate. Each hospital caring for patients with acute stroke will need to determine its own demand for intraarterial therapy and employ an adequate supply of qualified neurointerventionists available to meet demand. Comprehensive stroke centers are now being designated and hopefully will foster a rational, regionalized approach to the delivery of endovascular therapies for stroke.
The Reflected Weibull Distribution

For combinations of parameter values ordinarily encountered in life testing and reliability data, the similarity of the Weibull with the Pearson Type III (gamma) distri-bution is well known. When the Weibull distribution is reflected about the vertical axis x = γ, we obtain a version with cumulative probability function When δ > δ0, where to 13 decimals δ0 = 3.6023494257197, we have a distribution with positive skewness (i.e., α3 > 0), which for certain combinations of parameter values, closely resembles the Pearson Type VI distribution. It is to be noted that when δ = δ0, then α0 = 0. The fil, β1, β2 curves (Pearson's Betas) for the case in which δ > δ0 and for the case in which 0 < δ < δ0, are presented. An illustrative example is included to demonstrate use of the reflected Weibull in fitting sample data and to provide comparisons with results obtained from fitting the Type VI, Type III, Type V, and lognormal distributions.
REPLACEMENT OF THE BIZELESIN UREADIYL LINKAGE BY A GUANIDINIUM MOIETY RETARDS TRANSLOCATION FROM MONOALKYLATION TO CROSS-LINKING SITES ON DNA

In this contribution we demonstrate that Bizelesin can translocate along the minor groove of DNA from a kinetically favored monoalkylation site to a thermodynamically favored cross-linking site. This translocation is prevented in compounds that have a charged guanidino linkage substituting for the ureadiyl linkage. Furthermore, the manipulative interplay of Bizelesin and the target sequence 5‘-TAATTA (Seaman, F. C.; Chu, J.; Hurley, L. H. J. Am. Chem. Soc. 1996, 118, 5383−5395) that is required to produce a suitably rearranged product for cross-linking is prevented by the substitution of a guanidino for the ureadiyl linkage. A structural basis involving hydrogen bonding of the guanidino linkage with phosphates on the backbone of DNA is proposed to account for the absence of translocation, the slow conversion of monoalkylated to cross-linked species, and the non-rearranged cross-linked product.
Uterine Leiomyomas Express Myometrial Contractile-Associated Proteins Involved in Pregnancy-Related Hormone Signaling:

We used an animal model to study uterine leiomyoma in the context of pregnancy-associated changes in gene expression and to determine how they might modulate tumor growth. Spontaneous tumors and normal myometrium were collected from Eker rats and compared with myometrial samples from pregnant animals. A leiomyoma-derived cell line was also used to assess pregnancy-related changes in gene expression and to determine the impact of signaling by the oxytocin receptor. Eker rat leiomyomas expressed several pregnancy-related genes, including connexin 43, oxytocin receptor (OTR), and cyclooxygenase (COX)-1; however, the tumors did not express COX-2, which is expressed in the parturient myometrium. The leiomyoma-derived cell lines also expressed OTR, which responds to estrogen, binds to oxytocin, and exhibits a calcium flux when stimulated with oxytocin. The OTR signaling mediated by oxytocin inhibited estrogen-stimulated growth of leiomyoma cells. Leiomyoma cells expressed many genes of the parturient myometrium, including OTRs, but were deficient in COX-2 expression. Signaling via the OTR appears to inhibit estrogen-induced cell proliferation, suggesting that signaling by this receptor might help mediate the protective effect of pregnancy on this disease.
Public Experiences of Police Violence and Corruption in Contemporary Russia : A Case of Predatory Policing?

“Predatory policing” occurs where police officers mainly use their authority to advance their own material interests rather than to fight crime or protect the interests of elites. These practices have the potential to seriously compromise the public's trust in the police and other legal institutions, such as courts. Using data from six surveys and nine focus groups conducted in Russia, we address four empirical questions: (1) How widespread are public encounters with police violence and police corruption in Russia? (2) To what extent does exposure to these two forms of police misconduct vary by social and economic characteristics? (3) How do Russians perceive the police, the courts, and the use of violent methods by the police? (4) How, if at all, do experiences of police misconduct affect these perceptions? Our results suggest that Russia conforms to a model of predatory policing. Despite substantial differences in its law enforcement institutions and cultural norms regarding the law, Russia resembles the United States in that direct experiences of police abuse reduce confidence in the police and in the legal system more generally. The prevalence of predatory policing in Russia has undermined Russia's democratic transition, which should call attention to the indispensable role of the police and other public institutions in the success of democratic reforms.
Bounds for the CRDT Conformal Mapping Algorithm

In [16] Driscoll and Vavasis described their CRDT algorithm for numerical computation of conformal maps. Although the method works well in practice, it is not proven to converge and they formulated a number of conjectures to quantify its behavior. In this paper we prove one of these conjectures: that the initial guess of the CRDT algorithm always lies within a uniformly bounded distance of the correct answer.
ORGANOPHOSPHATE ADSORPTION ON NANOSIZED SILICA AND SILICA/ALUMINA: SURFACE INTERACTIONS AND BEHAVIOR OF ADSORBENTS

Organophosphate compounds (OPs) are common in pesticides and can be highly toxic. Negative environmental impacts resulting from the release of OPs can be reduced with rapid detection, which relies on sensitive sampling techniques. In this work, nanosized silica and silica/alumina were tested for their ability and behavior in adsorbing gas-phase dimethyl methylphosphonate (DMMP). Surface interactions were probed using Fourier transform infrared (FT-IR) spectroscopy with attenuated total reflectance (ATR) to establish correlations between surface properties and adsorption behavior. Adsorption characteristics were also investigated by gas chromatography (GC) equipped with a flame ionization detector (FID). Silica and silica/alumina adsorbents were exposed to DMMP in a flow system. FT-IR spectroscopy revealed that physical interactions between the adsorbents and DMMP were attributed to the presence of surface silanol. GC-FID results showed that adsorption onto both silica and silica/alumina followed Langmuir isotherm behavior. Silica demonstrated superior adsorption behavior as compared to silica/alumina. The following Langmuir isotherm constants are representative of the data: 0.88 for silica and 0.82 for silica/alumina.
Facilitated transport mechanism in fixed site carrier membranes

Abstract Facilitated transport of gases, such as O 2 , has been observed for fixed site carrier membranes. Carrier-impregnated ion-exchange membranes have also been used to produce facilitated transport of CO 2 , H 2 S and olefins when the carriers are not completely mobile. The actual mechanism for this facilitated transport has not been determined previously. The facilitated transport is provided by the exchange of solute between the free solute region and the bound complexing agent combined with gradients in the free solute and complexed carrier. The ratio of mobility for exchange between the regions is the dimensionless equilibrium constant of the reversible reaction. An expression is also derived for the relationship between the effective diffusion coefficient of the complex in facilitated transport, D AB , and the diffusion coefficients for exchange between free and complexed solute, D DH and D HD . Since D AB can be determined from experimental results, D DH and D HD can be calculated. The results also show the morphology dependence of D AB . The diffusion coefficient of the free solute D A also changes with the loading of the complexing agent in the film. This morphology dependence can explain why the gas permeability can decrease when the concentration of the complexing agent increases in the membrane.
Evidence That DNA (Cytosine-5) Methyltransferase Regulates Synaptic Plasticity in the Hippocampus

DNA (cytosine-5) methylation represents one of the most widely used mechanisms of enduring cellular memory. Stable patterns of DNA methylation are established during development, resulting in creation of persisting cellular phenotypes. There is growing evidence that the nervous system has co-opted a number of cellular mechanisms used during development to subserve the formation of long term memory. In this study, we examined the role DNA (cytosine-5) methyltransferase (DNMT) activity might play in regulating the induction of synaptic plasticity. We found that the DNA within promoters for reelin and brain-derived neurotrophic factor, genes implicated in the induction of synaptic plasticity in the adult hippocampus, exhibited rapid and dramatic changes in cytosine methylation when DNMT activity was inhibited. Moreover, zebularine and 5-aza-2-deoxycytidine, inhibitors of DNMT activity, blocked the induction of long term potentiation at Schaffer collateral synapses. Activation of protein kinase C in the hippocampus decreased reelin promoter methylation and increased DNMT3A gene expression. Interestingly, DNMT activity is required for protein kinase C-induced increases in histone H3 acetylation. Considered together, these results suggest that DNMT activity is dynamically regulated in the adult nervous system and that DNMT may play a role in regulating the induction of synaptic plasticity in the mature CNS.
Mechanistic studies for the limitation of carbon supercapacitor voltage

This paper investigates the discrepancy between double-layer supercapacitor voltage and the maximum electrochemical window voltage in an alkaline electrolyte. The electrochemical window is determined by the potential difference between hydrogen evolution and oxygen evolution. As the specific capacitance of a negatively polarized carbon material may be different from its positively polarized counterpart, the hydrogen evolution and oxygen evolution in the electrode may not occur at the same time. To achieve the electrochemical window voltage, the two electrodes in a double-layer supercapacitor need to be balanced and have the same capacitance to ensure that oxygen and hydrogen are generated at the same time.
Understanding gendered attrition in IT programs

In this paper, we describe the problem of gendered attrition in a program of Information Technology and discuss the research design for a two-year study funded by the National Science Foundation to study women in information technology programs nationwide.
Dynamic recrystallization-induced flow phenomena in tungsten–tantalum (4%) [001] single-crystal rod ballistic penetrators

Abstract Deformation-flow microstructures associated with [001] W–4% Ta penetrator fragments in a rolled homogeneous steel armor target exhibit dynamic recrystallization. The equiaxed, recrystallized grain structure observed in the deformed penetrator is also associated with soft zones in corresponding microhardness maps. Microstructure evolution is also examined by transmission electron microscopy (TEM) and selected-area electron diffraction (SAED).
The SRY Cantilever Motif Discriminates Between Sequence- and Structure-Specific DNA Recognition: Alanine Mutagenesis of an HMG Box

Summary The high-mobility-group (HMG) box defines a DNA-bending motif conserved among architectural transcription factors. A “hydrophobic wedge” at the protein surface provides a mechanism of DNA bending: disruption of base stacking by insertion of a sidechain “cantilever.” First described in the mammalian testis-determining factor SRY, the cantilever motif consists of adjacent aromatic and nonpolar sidechains at the crux of the HMG box (residues 12 and 13). Here, the role of these side chains in DNA recognition is investigated by alanine mutagenesis. F12A and I13A substitutions in the SRY HMG box each permit native folding and thermal stability (as monitored by circular dichroism and 1H-NMR) but eliminate sequence-specific DNA-binding activity (as detected by gel-mobility shift). On binding to the sharp angles of a four-way DNA junction (4WJ), however, the substitutions each promote formation of a high-molecular-weight aggregate, presumably by DNA-dependent oligomerization. The substitutions have opposit...
Quantum diffusion in solid H 2

A study of quantum diffusion in solid H2 is reported based on the measurement of the pressure versus time at constant volume. Solid samples with ortho-H2 concentrations between 0.01 and 0.025 were investigated over the temperature range 0.4–4 K. The characteristic time constant Τ for ortho pair formation or breaking up and the resulting pressure changes are presented and compared with other experiments and with theory. The pressure change calculated from a simple statistical model is in good agreement with the experiment and this leads to the conclusion that both in-plane and out-of-plane pairs appear to form (or break up) at the same rate, at least in our concentration range. The experiments also suggest that the concentration dependence of Τ is in qualitative agreement with theory, which, however, makes no predictions on the temperature dependence. Comparison with other experiments also suggests that Τ might be a function of strains in the sample.
Barbiturate attenuation of brain free fatty acid liberation during global ischemia.

To find a biochemical basis for the increased tolerance of the brain to anoxia during barbiturate anesthesia, we studied whole-brain free fatty acids (FFA) at various times after decapitation of awake and pentobarbital-anesthetized rats. Post-decapitation, the brains were kept at 37 degrees C for 1 to 60 min before freezing in liquid N2. Nonischemic brains were frozen in liquid N2, using a rapid sampling technique. Whole-brain arachidonic, stearic, oleic, linoleic, and palmitic acids were quantitated by gas-liquid chromatography. In unanesthetized, nonischemic brain, total FFA was 1226 +/- 121 nmol/g brain (n = 12) and was unaffected by pentobarbital anesthesia (1126 +/- 86 nmol/g brain, n = 11), except for a reduction in arachidonic acid. Total FFA in unanesthetized and pentobarbital-anesthetized rats transiently declined between 0 and 1 min of ischemia, and then rose linearly for up to 60 min, with consistently lower values in pentobarbital-treated rats, the greatest attenuation being that of arachidonic and stearic acid liberation. Brain FFA liberation during global ischemia is the first known biochemical variable directly correlated with the duration (i.e., severity) of global ischemia. The attenuation of brain FFA liberation and especially of arachidonic and stearic acids may be the biochemical basis of barbiturate attenuation of ischemic brain injury.
Low dielectric losses in annealed Ti-doped K(Ta,Nb)O3 thin films grown by pulsed laser deposition

We have investigated the dielectric properties of Ti-doped K(Ta,Nb)O{sub 3} films subjected to high temperature annealing. Titanium (+4) substitution on the Nb/Ta site introduces an acceptor state, thus reducing dielectric losses due to defect-related donor states. Using 3% Ti-doped targets, K(Ta,Nb)O{sub 3}: Ti films were grown on MgO (001) crystals by pulsed-laser deposition. The films were annealed in oxygen at temperatures as high as 1000 C. A loss tangent of 0.002 at room temperature was observed for annealed Ti-doped K(Ta,Nb)O{sub 3} thin films. A reduction in tunability was also seen. For these annealed films, the dielectric loss shows little temperature dependence, indicating a significant reduction in donor density due to defects.
Usefulness of Frequent Supraventricular Extrasystoles and a High CHADS2 Score to Predict First-Time Appearance of Atrial Fibrillation

Frequent supraventricular extrasystoles (SVEs) are associated with the subsequent first-time appearance of atrial fibrillation (AF) and ischemic stroke. The aim of this study was to investigate the combined role of SVEs and an AF-related risk score for ischemic stroke, the CHADS 2 score, on the occurrence of new AF in patients in sinus rhythm. The Shinken Database 2004–2010 lists 3,263 patients who underwent 24-hour Holter monitoring. A total of 2,589 patients were analyzed, after excluding 674 patients previously diagnosed with AF. Frequent SVEs were defined as ≥102 beats/day (the top quartile) and the presence of a clinical background for a CHADS 2 score ≥2 points as a high CHADS 2 score. During the mean follow-up period of 571.4 ± 606.4 days, new AF occurred in 38 patients (9.4 per 1,000 patient-years). The incidence of new AF was 2.7 and 37.7 per 1,000 patient-years for patients with nonfrequent SVEs ( 2 scores and those with frequent SVEs and high CHADS 2 scores, respectively. Multivariate Cox regression analysis showed that the hazard ratio for frequent SVEs and a high CHADS 2 score compared with nonfrequent SVEs and a low CHADS 2 score was 9.49 (95% confidence interval 3.20 to 28.15, p 2 score independently and synergistically predict the first-time appearance of AF in patients in sinus rhythm, indicating an approximately 10-fold higher risk. Patients meeting these criteria should have more aggressive early intervention for preventing AF.
Performing a water footprint assessment for a semiconductor industry

In recent years, Intel Corporation (Intel) has established itself as a leader in assessing its greenhouse gas (GHG) emissions. This leadership role was established after many years of effort driven by a wide range of external drivers. New demands by many of the same external entities now require companies like Intel to perform comprehensive reviews of their water footprints. Unlike carbon footprinting, the water footprint assessment framework is currently not well-defined. However, many of the steps taken in the GHG footprint arena have given us a significant head start for our reviews associated with water impacts. Intel's water footprint assessment followed a parallel methodology as our carbon footprint assessment efforts. This included Intel's manufacturing water usage, electricity production, and the majority of our supply chain for manufacturing. Our assessment revealed that Intel's manufacturing, where we have been focused on water conservation for many years, requires the most amount of water. We also discovered that if it were not for our existing program to purchase Renewable Energy Certificates (REC), electricity production would have been the most water intensive. The vast limitations on obtaining water data from suppliers, and data on water use per electricity source creates obstacles on developing a more accurate water footprint. Intel has conducted their assessment conservatively and believes that gaining any knowledge on where their water impacts lie will provide information to aid in reducing their overall water impacts.
Radiative-Dynamical Consequences of Dry Tongues in the Tropical Troposphere

Abstract Dry layers are frequently observed in atmospheric soundings from the climatologically humid western Pacific warm pool region. Some 2400 soundings from the TOGA COARE field program were objectively examined for humidity drops (layers in which relative humidity decreases rapidly with height), indicative of the bases of dry layers. These occur throughout the lower and middle troposphere, with frequency peaks near 550 (the 0°C level), 800, and 950 mb. A composite constructed from these sounding data indicates the following. Almost all dry layers are too dry (and not warm enough) to be interpreted as conservative vertical displacements. Rather, they apparently consist of filaments or tongues of low moist static energy air advected into the column, often from the subtropics. Dry tongues are anomalously virtually warm near their bases with a slight cool layer below; that is, they sit atop sharp stable layers or inversions. The authors hypothesize that radiation is responsible for the thermal structure o...
‘Green’ composites from soy based plastic and pineapple leaf fiber: fabrication and properties evaluation

Abstract Soy based bioplastic and pineapple leaf fiber ‘Green’ composites were manufactured using twin-screw extrusion and injection molding. Thermal properties, mechanical properties and morphology of the green composites were evaluated with Dynamic Mechanical Analyzer (DMA), United Testing System (UTS) and Environmental Scanning Electron Microscopy (ESEM). The effects of fiber loading and polyester amide grafted glycidyl methacrylate (PEA- g -GMA) as compatibilizer on morphology and physical properties of pineapple leaf fiber reinforced soy based biocomposites were investigated. The mechanical properties including tensile properties, flexural properties and impact strength of the biocomposites increased with increasing fiber content and the presence of the compatibilizer. ESEM studies reveal that the dispersion of fiber in the matrix became worse with increasing fiber content but improved with addition of compatibilizer. The addition of the compatibilizer also decreased the water absorption. The improved mechanical properties of the composites correspond, in the presence of the compatibilizer, is attributed to interactions between hydroxyl groups in the pineapple leaf and epoxy groups in PEA- g -GMA.
Polyelectrolytes prepared from perfluoroalkylaryl macromolecules

The synthesis of a new generation of high-capacity oxidation-resistant ion-exchange resins and membranes is described which are sulfonic acid polyelectrolytes prepared from high molecular weight poly-α,β,β-trifluorostyrene. The difficult sulfonation of poly-α,β,β-trifluorostyrene is discussed in terms of the finding that this sulfonation must be effected upon an aromatic ring possessing a meta-directing substituent group. The oxidative stability of these new types of perfluoroalkyl aromatic sulfonic acid polyelectrolytes is both demonstrated and described with comparisons to their polystyrenesulfonic acid homologs. The difference in their oxidation–depolymerization stabilities is described in terms of benzylic carbon substituents.
The Choice of Sourcing Mechanisms for Business Processes

There is unprecedented interest in digitally enabled extended enterprises that enable firms to gain access to specialized skills and capabilities globally. Given this motivation, firms are unbundling their value chain processes and exploring new sourcing mechanisms. With the emergence of world-class skills and capabilities in offshore locations, new sourcing mechanisms have become available beyond traditional domestic insourcing and outsourcing. However, there is little systematic research examining how firms choose sourcing mechanisms for their business processes. This study views the digitally enabled extended enterprise as a complex system of business processes and examines how sourcing choices are made in such enterprises. It builds on the modular systems theory to posit that modularization of business processes and their underlying information technology (IT) support infrastructures are associated with the choice of sourcing mechanisms for the processes. The study tests this proposition in a sample of business process sourcing choices made by 93 medium and large U.S. firms. The results show that firms tend to choose domestic outsourcing for processes that are high in modularity and offshore outsourcing for processes that are low in modularity. Further, when processes can be detached from a firm's IT infrastructure, firms tend to use offshore outsourcing. However, when processes are tightly coupled with underlying IT infrastructure, it may be infeasible to detach processes and execute them in remote locations. Implications for theory and practice are also discussed.
The 1990s--interface of cytopathology and new technology.

Abstract In physical chemistry, the most unique and dramatic reactions occur at the interface between different phases of matter. An analogy can be drawn between this observation and the interface that currently exists between the traditional practice of cytopathology and the technologies discussed in this editorial. It is natural to be excited about new technologies. They offer the potential to improve our diagnostic ability, to save time, and to expand the range of cytopathology services. Our enthusiasm for new technology should be tempered by the inherent appeal of cytopathology--its relative simplicity. Cytologic diagnoses are possible with a glass slide, extracts of tree bark, and a well-trained observer. This can be rapid and tremendously cost effective, not only identifying the type of abnormality, but often providing prognostic information. New technology, while offering additional information, may not be cost effective, or may not offer more information than is available by traditional methods. Whether or not to accept new technologies is the choice of cytotechnologists and cytopathologists. It is the goal of the Editorial Board of Diagnostic Cytopathology that this be a well-informed choice. The current and coming issues of Diagnostic Cytopathology will describe technological advances in the Focus on Technology section of the journal. We trust that you will find this information useful in your evaluation of new technology.
Thermal sensitivity and thermal tolerance of human B-lineage acute lymphoblastic leukemia (ALL) cells.

Abstract The thermal sensitivities of four B-cell precursor acute lymphoblastic (ALL) cell lines (REH and KM-3 = pre pre B-ALL; NALM-6 and HPB-NULL = pre B-ALL), and 1 B-cell ALL (NAMALWA) cell line were studied and compared to the thermal sensitivity of the T-lineage ALL cell line MOLT-3 using an in vitro clnogenic assay system by limiting dilution. B-lineage ALL cells were as sensitive to hyperthermia as were T-lineage ALL cells. D 0 values at 42°C ranged from 44.9 min (NALM-6) to 85.6 min (NAMALWA), D 0 values at 43°C ranged from 15.3 min (NALM-6) to 35.7 min (KM-3), and D 0 values at 44°C ranged from 11.1 min (NALM-6) to 23.8 min (HPB-NULL). By comparison, the D 0 values of MOLT-3 cells were 95.1 min at 42°C, 23.8 min at 43°C, and 14.7 min at 44°C. The maximum log kill values which were observed ranged from 0.8 log (KM-3 and HPB-NULL) to 1.3 logs (NALM-6) at 42°C, from 1.4 logs (KM-3) to 4.2 logs (NALM-6) at 43°C, and from 3.8 logs (HPB-NULL) to 4.8 logs (NALM-6) at 44°C. A thermal tolerant plateau was observed in the hyperthermia survival curves of REH, NALM-6, and HPB-NULL cells, providing circumstantial evidence that thermal tolerance may develop in some B-cell precursor ALL cells after 90–120 min of continuous heating. In contrast, no thermal tolerant plateau was observed in the hyperthermia survival curves of pre-pre-B-ALL/KM-3 B-cell ALL/NAMALWA or T-lineage ALL/MOLT-3 cells. The kinetics of development and decay of thermotolerance was studied for NALM-6 cells. Thermotolerance after a priming heat exposure to 42°C for 30 min was maximum at 8 hr with a maximum thermotolerance ratio of 2.0, and it decayed by 24 hr. These findings extend previous studies on the thermal sensitivity of human leukemia cells and provide new information on the thermal sensitivity and thermotolerance of B-lineage ALL cells.
“A calculated risk”: the Salk polio vaccine field trials of 1954

The polio vaccine field trials of 1954, sponsored by the National Foundation for Infantile Paralysis (March of Dimes), are among the largest and most publicised clinical trials ever undertaken. Across the United States, 623 972 schoolchildren were injected with vaccine or placebo, and more than a million others participated as “observed” controls. The results, announced in 1955, showed good statistical evidence that Jonas Salk's killed virus preparation was 80-90% effective in preventing paralytic poliomyelitis.1 The statistical design used in this great experiment was singular, prompting criticism at the time and since. Eighty four test areas in 11 states used the textbook model: in a randomised, blinded design all participating children in the first three grades of school (ages 6-9) received injections of either vaccine or placebo and were observed for evidence of the disease. But 127 test areas in 33 states used an “observed control” design: participating children in the second grade (ages 7-8) received injections of vaccine; no placebo was given, and children in all three grades were then observed for the duration of the polio “season.”1 The use of the dual protocol illustrates both the power and the limitations of the randomised clinical trial to legitimate therapeutic claims. The placebo controlled trials were necessary to define the Salk vaccine—introduced by a lay organisation that has taken an activist position against the counsel of its virological advisers—as the product of scientific medicine. The observed control trials were essential to maintaining public support for the vaccine as the product of lay faith and investment in science. Here I examine the process by which the trial design was negotiated and the roles of the several actors. ### Summary points The 1954 polio vaccine field trials used a singular statistical design Over 600 000 schoolchildren were injected with vaccine or placebo and over …
A high resolution study of the excitation spectrum of phosphorus donors introduced in silicon by neutron transmutation

Abstract The electronic excitation spectrum of phosphorus donors in silicon generated by neutron transmutation has been observed. High resolution of a Fourier Transform spectrometer combined with “strain free” mounting technique revealed line widths much narrower than reported earlier. The line widths and shapes as affected by the presence of charged defects produced by the neutron irradiation were studied. An explanation for the observed line width and shape is proposed.
Nonsustained ventricular tachycardia during programmed ventricular stimulation: criteria for a positive test

Abstract Controversy persists among groups carrying out programmed ventricular stimulation (PVS) as to which criteria should be used to define a positive test. To examine this question, the results of PVS carried out in 50 patients with documented sustained ventricular tachycardia (VT) or ventricular fibrillation were retrospectively analyzed. All patients underwent serial PVS using single and double extrastimuli and ventricular burst pacing in the right ventricle and, when necessary, the left ventricle, with sustained VT elicited during the control study in each patient. Antiarrhythmic drugs were then administered, with therapy tailored to both PVS result and ambulatory Holter monitoring, when possible. All patients were maintained and followed on the same drugs and dosages as at the time of predischarge PVS. After mean 20 months follow-up, 28 patients either died suddenly (8 patients) or had documented sustained VT (20 patients). The ability to induce nonsustained or sustained VT on predischarge PVS was associated with a significantly higher likelihood of subsequent sudden death or VT recurrence than if VT could not be induced (p
New Kids on the Block: My First Time in a Political Community:

A historic election in 2008 brings up new questions about why there is a generational difference in political engagement. Younger generations became more involved in the latest election, and it is important for scholars to understand why this change occurred. In an effort to begin this conversation, the researchers asked young citizens to talk about their choice to vote or not vote, and to become more involved or ignore campaign 2008. Through a focus group investigation and an analysis of citizens’ responses, the researchers hope to further understand young citizens. Two themes found within the discussions are consistent with previous research: community and efficacy. However, this study explains some of the ways that these two motivations for action might be interlinked.
Culturally Appropriate Assessment of Functional Impairment in Diverse Children: Validation of the ADHD-FX Scale With an At-Risk Community Sample:

Objective: In an effort to reduce disparities in ADHD diagnoses and treatment across cultures, the current study sought to establish initial psychometric and cultural properties of the ADHD-FX: a culturally sensitive assessment measure of functional impairment related to ADHD for diverse families. Method: Fifty-four Latino parents (44 mothers and 10 fathers) of school-aged children completed the ADHD-FX, as well as several other measures assessing child behavior and parent acculturation. Results: The ADHD-FX demonstrated adequate reliability (as demonstrated by internal consistency and test–retest reliability), psychometric construct validity (as demonstrated by associations with theoretically related measures), and cultural validity (as demonstrated by or lack of associations with acculturation measures). Conclusion: Initial psychometric and cultural properties suggest that the ADHD-FX is a reliable, valid, and culturally appropriate measure to assess functional impairment related to ADHD (i.e., difficul...
Stability of Chemically Crosslinked Microtubules

Microtubules (MT) are dynamic protein-based polymers with numerous applications in materials science including the active transport of nanomaterials and as templates for biomimetic materials synthesis. Some of these applications require that the dynamic nature of the MT be suppressed, and in this report we will discuss the preparation and stability of chemically crosslinked microtubules (CLMTs). MT reaction with gluteraldehyde results in the formation of protein dimers and higher molecular weight oligimers as observed by gel electrophoresis, confirming the formation of covalent inter-protein linkages. While extensive crosslinking was found to destabilize MTs and inactivate them with regards to kinesin binding, moderate amounts of crosslinking lead to CLMTs that had functional lifetimes of at least twice that of uncrosslinked MTs. Further studies demonstrated that CLMTs exhibited a wider thermal stability window and were far more resistant to metal-ion induced depolymerization than uncrosslinked MTs.
SULFATES IN THE ATMOSPHERE: A PROGRESS REPORT ON PROJECT MISTT*

Abstract The size and sulfate content of atmospheric aerosols and the rate and mechanisms for sulfate formation from sulfur dioxide in power plant plumes are reviewed. Emphasis is given to results from the recent USEPA study, Project MISTT (Midwest Interstate Sulfur Transformation and Transport). The rate of conversion of sulfur dioxide to sulfate aerosol in power plant plumes is low near the point of emission, but increases to several per cent h −1 as ambient air mixes with the plume. Tall stacks reduce ground level concentrations of sulfur dioxide, resulting in a reduction of the amount removed by dry deposition. In urban plumes, which are well-mixed to the ground near the source, sulfur dioxide is removed more rapidly by dry deposition. Thus, tall stacks increase the atmospheric residence time of sulfur dioxide, which leads to an increase in atmospheric sulfate formation. These sulfate aerosols may be transported over distances of several hundred kilometers and produce air pollution episodes far from the pollution source.
Medical imaging: Sleuthing tissue fingerprints.

A type of data-acquisition sequence in magnetic resonance imaging has been developed that rapidly and robustly quantifies properties of imaged tissue by elucidating a characteristic signal fingerprint. See Article p.187 Although nuclear magnetic resonance is a powerful analytical tool for many scientific and medical disciplines, usually only a fraction of its potential power is harnessed. Most implementations are qualitative, and restricted in the range of properties that are probed. Dan Ma and colleagues introduce a new approach — termed magnetic resonance fingerprinting — aimed at greatly enhancing the amount of quantitative information that can be obtained in one measurement. Their approach combines a data-acquisition scheme that is indiscriminate in the material properties that it probes with pattern-recognition algorithms that look for the 'fingerprints' of interest within the data. Magnetic resonance fingerprinting has the potential to detect and analyse early indicators of disease or complex changes in materials, as well as increasing the sensitivity, specificity and speed of magnetic resonance studies.
Distinguishability of stacks in ZnTe/ZnSe quantum dots via spectral analysis of Aharonov-Bohm oscillations

A spectral analysis of the Aharonov-Bohm (AB) oscillations in photoluminescence intensity was performed for stacked type-II ZnTe/ZnSe quantum dots (QDs) fabricated within multilayered Zn-Se-Te system with sub-monolayer insertions of Te. Robust AB oscillations allowed for fine probing of distinguishable QDs stacks within the ensemble of QDs. The AB transition magnetic field, B AB , changed from the lower energy side to the higher energy side of the PL spectra revealing the presence of different sets of QDs stacks. The change occurs within the spectral range, where the contributing green and blue bands of the spectra overlapped. “Bundling” in lifetime measurements is seen at transition spectral regions confirming the results.
A new paradigm in leaf-level photosynthesis: direct and diffuse lights are not equal.

Global-change scenarios suggest a trend of increasing diffuse light due to expected increases in cloud cover. Canopy-level measurements of plant-community photosynthesis under diffuse light show increased productivity attributed to more uniform distribution of light within the forest canopy, yet the effect of the directional quality of light at the leaf level is unknown. Here we show that leaflevel photosynthesis in sun leaves of both C3 and C4 plants can be 10–15% higher under direct light compared to equivalent absorbed irradiances of diffuse light. High-lightgrown leaves showed significant photosynthetic enhancement in direct light, while shade-adapted leaves showed no preference for direct or diffuse light at any irradiance. Highlight-grown leaves with multiple palisade layers may be adapted to better utilize direct than diffuse light, while shade leaf structure does not appear to discriminate light based on its directionality. Based upon our measurements, it appears that leaf-level and canopy-level photosynthetic processes react differently to the directionality of light, and previously observed increases in canopy-level photosynthesis occur even though leaf-level photosynthesis decreases under diffuse light.
Nonlinear optical techniques for obtaining high brightness from diode lasers

How nonlinear optics can be used to obtain high brightness from diode lasers is described. The use of two-wave mixing to combined and clean up the output of any frequency-locked high-power device is addressed. The application of phase conjugation for coupling to lock lasers is considered.
Managing the Threat of Impending Implicit Attitude Feedback

People facing potentially threatening feedback sometimes opt to avoid it in an attempt to preserve a cherished self-view. In three studies, we examined whether people would adopt such a strategy in...