cssi/SciSciGPT-SciSciNet huggingface dataset:
The Siren Song: Algorithmic Governance By Blockchain

A central theme in internet history since the 1990s is the rise of algorithmic power, enabled through the self-restraint of human governments. Digital platforms were born weak and clumsy. Governments could have stamped them out to enforce traditional territorial boundaries and regulatory categories. They chose not to. Once the digital tornado was unleashed, however, its path was not easily directed. Fledgling innovators in need of protection developed into dominant platforms that transformed many aspects of the world for the better, but also created serious harms through pervasive data collection and automated decision-making. The threats arose from the very attributes that made these digital systems so appealing. The cycle is now repeating itself. Another broad-based technological shift is empowering market entrants that promise huge gains in both efficiency and freedom. And once again, the deeper challenge is how to regulate their own penchant for algorithmic overreach. Blockchain and cryptocurrency technologies are today’s digital tornado. Like the internet, they are stimulating dramatic levels of investment, startup activity, and media attention, as well as creating massive disruption of industries and passionate visions of societal transformation. As with the internet, this excitement often gets ahead of reality. The internet economy recovered from the dotcom crash of the early 2000s to realize its potential through the growth of social media, cloud computing, and mobile connectivity. The crypto economy seems likely to experience a similar trajectory over time. To succeed at scale, however, blockchain-based networks and services will need address the problem of governance. Immutability, the mechanism that allows these systems to generate trust without central authorities, also creates inherent weaknesses that sometimes turn into catastrophic failures.
Interventions for increasing male and female undergraduate interest in information technology

There is a continuing worldwide need for developing a larger and more diverse workforce in the broad field of information technology (IT). We report on two activities conducted by the project within selected classes of a postsecondary finite mathematics course: 1) a student-written blog about practical applications of computing, and 2) after-class seminar sessions with professionals about the importance of computing in the work world. It was found that the hundreds of students who actively participated in these activities were significantly more likely to enroll in a computing course or declare a computing-related major than were non-participating students, despite the fact that the two groups of students displayed identical attitudes toward computing at the start of the term. The study demonstrates that relevant blogs and sessions with professionals can be effective tools for recruiting students, including women, who otherwise would not have chosen to complete more course work in computing. Blog reading or meeting with computing professionals can generate interest in IT.Study population was drawn from general education mathematics course.Participating students were significantly more likely to enroll in IT courses or majors.Both male and female students were affected positively.Female students were more dramatically affected than males.
Different social drivers, including perceptions of urban wildlife, explain the ecological resources in residential landscapes

The conservation value of residential landscapes is becoming increasingly apparent in our urbanizing world. The ecological characteristics of residential areas are largely determined by the decisions of many individual “managers.” In these complex socio-ecological systems, it is important to understand the factors that motivate human decision-making. Our first objective was to quantify wildlife resources and management activities in residential landscapes and compare vegetation in front and back yards. Our second objective was to test three hypotheses linked with variation in yards: socioeconomic characteristics, neighborhood design factors, and perceptions of neighborhood birds. We conducted surveys of over 900 residents in 25 Chicago-area neighborhoods to examine the wildlife resources contained in front and back yards and the social factors associated with variation in yards. We used a multi-scalar approach to examine among-yard and among-neighborhood variation in residential landscapes. Results indicate that back yards contain more wildlife resources than front yards, including greater vegetation complexity, more plants with fruit/berries, and more plants intended to attract birds. Furthermore, different hypotheses explain variation in front and back yards. Perceptions of birds were most important in explaining variation in back yard vegetation and wildlife-friendly resources per parcel, while neighbors’ yards and socioeconomic characteristics best explained front yard vegetation. This study demonstrates the importance of back yards as an unexplored and underestimated resource for biodiversity. In addition, the results provide insight into the complex factors linked with yard decisions, notably that residents’ connections with neighborhood birds appear to translate to on-the-ground actions.
Strong sub-and super-gaussianity

We introduce the terms strong sub- and super-Gaussianity to refer to the previously introduced class of densities log-concave is x2 and log-convex in x2 respectively. We derive relationships among the various definitions of suband super-Gaussianity, and show that strong sub- and super-Gaussianity are related to the score function being star-shaped upward or downward with respect to the origin. We illustrate the definitions and results by extending a theorem of Benveniste, Goursat, and Ruget on uniqueness of separating local optima in ICA.
Development of an ovarian cancer screening decision model that incorporates disease heterogeneity: implications for potential mortality reduction.

BACKGROUND: Pathologic and genetic data suggest that epithelial ovarian cancer may consist of indolent and aggressive phenotypes. The objective of the current study was to estimate the impact of a 2-phenotype paradigm of epithelial ovarian cancer on the mortality reduction achievable using available screening technologies. METHODS: The authors modified a Markov model of ovarian cancer natural history (the 1-phenotype model) to incorporate aggressive and indolent phenotypes (the 2-phenotype model) based on histopathologic criteria. Stage distribution, incidence, and mortality were calibrated to data from the Surveillance, Epidemiology, and End Results Program of the US National Cancer Institute. For validation, a Monte Carlo microsimulation (1000,000 events) of the United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) multimodality prevalence screen was performed. Mortality reduction and positive predictive value (PPV) were estimated for annual screening. RESULTS: In validation against UKCTOCS data, the model-predicted percentage of screen-detected cancers diagnosed at stage I and II was 41% compared with 47% (UKCTOCS data), and the model-predicted PPV of screening was 27% compared with 35% (UKCTOCS data). The model-estimated PPV of a strategy of annual population-based screening in the United States at ages 50 to 85 years was 14%. The mortality reduction using annual postmenopausal screening was 14.7% (1-phenotype model) and 10.9% (2-phenotype model). Mortality reduction was lower with the 2-phenotype model than with the 1-phenotype model regardless of screening frequency or test sensitivity; 68% of cancer deaths are accounted for by the aggressive phenotype. CONCLUSIONS: The current analysis suggested that reductions in ovarian cancer mortality using available screening technologies on an annual basis are likely to be modest. A model that incorporated 2 clinical phenotypes of ovarian carcinoma into its natural history predicted an even smaller potential reduction in mortality because of the more frequent diagnosis of indolent cancers at early stages. Cancer 2011. © 2010 American Cancer Society.
Identification of membrane proteins that comprise the plasmalemmal junction between migrating neurons and radial glial cells

We have initiated studies to identify membrane polypeptides of radial glial cells that contribute to the selective cell-cell recognition and migration events in developing brain. Of several polyclonal antisera evaluated, one (D4), developed against formaldehyde fixed type 1 cerebellar glial cells, immunolabels the free surface of cortical and cerebellar astroglial and radial glial cells in a patchy pattern. In dissociated glial-neuronal cell cocultures, microdomains of immunoreactivity are detected at the site where the somal region of cells with the morphology of migrating neurons is in contact with an elongated glial cell fiber. Microdomains are absent from oligodendrocytes, process-bearing astrocytes, and neurons. The surface microdomains do not colocalize with components that compose focal adhesion plaques--integrin subunits, vinculin, or actin--and their integrity appears to require an intact microtubule rather than actin cytoskeleton. Furthermore, microdomain structure is maintained in the absence of extracellular Ca and Mg ions. Immunoblot analyses using antibodies affinity purified to individual proteins indicate that the microdomains are composed of two antigens with apparent molecular mass of approximately 48 kDa and approximately 72 kDa. The 48 kDa antigen is not observed in non-neural epithelial tissues and is detected in cortical and cerebellar tissues only at a developmental period that coincides with the stage of active neuronal cell migration. In contrast, the 72 kDa antigen is expressed in many neural and non-neural tissues at late developmental and adult stages. Our data suggest that the identified membrane proteins may contribute to the formation of the junction between migrating neurons and radial glial cell processes and that this junctional complex is linked to the microtubule cytoskeleton.
Role of apolipoprotein D in the transport of bilirubin in plasma.

Apolipoprotein D (apo D) is a 30-kDa glycoprotein of unknown function that is associated with high-density lipoproteins (HDL). Because unconjugated bilirubin has been shown to bind apo D with a 0.8...
Use of active suspension control to counter the effects of vehicle payloads

This paper discusses the effects of payload changes in heavy machinery and a suspension control system to compensate for these changes. A half vehicle model is used in which the vertical and pitch motions of the mass supported by the suspension and the vertical motion of the suspension masses are considered. Upon receiving a load, the dynamics of a vehicle can change significantly. To simulate the change in vehicle load, the center of mass is moved and the total mass is increased. Various load changes are simulated by changing the amount by which the center of mass moves and varying the increase in the total mass. Suspension performance is measured for unloaded and loaded vehicles, and for loaded vehicles with passive and active suspension systems. Actively controlled suspensions systems are shown to improve vehicle dynamics for both front and rear-loaded vehicles.
Effect of the Amount of Tissue Grafted Upon Survival of Skin Homografts.

Summary1. Female mice of the C57B1 (Subline 1) strain capable of rejection of small male skin isografts regularly accepted large male skin isografts. 2. Large homologous skin grafts between genetically closely related strains were regularly rejected as were small skin homografts. 3. Large skin homografts between strains of mice characterized by strong histocompatibility differences regularly resulted in early death of the recipient. 4. Tolerance of C57B1(Subline 1) female mice to male skin isografts induced by spleen cell injection could be transferred by injection of spleen cells from tolerant donors to new females during the post-neonatal period. Attempts to transfer tolerance induced with a large skin graft were unsuccessful.
Leveraging collaboration for information literacy in psychology

A case study of the integration of information literacy into a psychology research course is presented. The process of integration began with developing learning outcomes, a four‐hour curriculum, exercises, and an assessment instrument, which were approved by the Psychology Department's undergraduate curriculum committee. Also emphasized is the ongoing exchange of expertise between liaison librarian and psychology faculty to enhance library‐related components in the design of the course. Difficulties in implementing the program are described, along with the use of outcome statistics to underscore the value of the partially implemented program. Librarians used data from student assessments to highlight the need for more intensive and extensive student training to meet learning objectives. The sometimes laborious process of academic negotiation is discussed, along with the resulting decision to develop a psychology literature tutorial through collaboration between a junior Psychology Department faculty member and a librarian.
Performance modeling for interconnects for conventional and emerging switches

This paper quantifies the challenges, limits, and opportunities of interconnects for evolutionary and revolutionary semiconductor technologies of the future. Various exploratory devices and the delays associated with their transport mechanisms are quantified. Graphene is selected as the interconnect material of choice because of its excellent transport properties over the conventional Cu/low-K: interconnects currently serving as the communication medium in integrated circuits. Compact models that describe the transport properties in graphene (electron mean free path, mobility, spin relaxation) are presented. These compact models are used to (i) evaluate the performance and energy-per-bit of graphene interconnects in electrical and spintronic domains and (ii) compare these metrics against those of conventional electrical interconnects at the end of silicon roadmap technology node (minimum feature size of 7.5 nm).
Multimode damage tracking and failure prognosis in electromechanical systems

In this paper a modification to a general-purpose machinery diagnostic/prognostic algorithm that can handle two or more simultaneously occurring failure processes is described. The method is based on a theory that views damage as occurring in a hierarchical dynamical system where slowly evolving, hidden failure processes are causing nonstationarity in a fast, directly observable system. The damage variable tracking is based on statistics calculated using data-based local linear models constructed in the reconstructed phase space of the fast system. These statistics are designed to measure a local change in the fast systems flow caused by the slow-time failure processes. The method is applied to a mathematical model of an experimental electromechanical system consisting of a beam vibrating in a potential field crated by two electromagnets. Two failure modes are introduced through discharging batteries supplying power to these electromagnets. Open circuit terminal voltage of these batteries is a two-dimensional damage variable. Using computer simulations, it is demonstrated both analytically and experimentally that the proposed method can accurately track both damage variables using only a displacement measurements from the vibrating beam. The accurate estimates of remaining time to failure for each battery are given well ahead of actual breakdowns.
A finite element method for localized failure analysis

A method is proposed which aims at enhancing the performance of general classes of elements in problems involving strain localization. The method exploits information concerning the process of localization which is readily available at the element level. A bifurcation analysis is used to determine the geometry of the localized deformation modes. When the onset of localization is detected, suitably defined shape functions are added to the element interpolation which closely reproduce the localized modes. The extra degrees of freedom representing the amplitudes of these modes are eliminated by static condensation. The proposed methodology can be applied to 2-D and 3-D problems involving arbitrary rate-independent material behavior. Numerical examples demonstrate the ability of the method to resolve the geometry of localized failure modes to the highest resolution allowed by the mesh.
Mathematical modelling of negative feedback regulation by carboxyltransferase

Acetyl-CoA carboxylase catalyses the first committed step in fatty acid synthesis in all organisms. The chemistry is accomplished in two half-reactions: activation of biotin via carboxylation by biotin carboxylase, followed by the carboxyltransferase-catalysed transfer of the carboxyl moiety from carboxybiotin to acetyl-CoA to generate malonyl-CoA. The Escherichia coli form of the carboxyltransferase subunit was recently found to regulate its own activity and expression by binding its own mRNA. By binding acetyl-CoA or the mRNA encoding its own subunits, carboxyltransferase is able to sense the metabolic state of the cell and attenuate its own translation and enzymatic activity using a negative feedback mechanism. Here, the network of these interactions is modelled mathematically with a set of non-linear differential equations. Numerical simulations of the model show that it qualitatively and quantitatively agrees with the experimental results for both inhibition of carboxyltransferase by mRNA and attenuation of translation. The modelling of the autoregulatory function of carboxyltransferase confirms that it is more than isolated interactions, but functions as a single dynamic system.
Uncertainties of 4-dimensional computed tomography-based tumor motion measurement for lung stereotactic body radiation therapy.

Abstract Purpose To evaluate how well tumor motion measured prior to treatment based on 4-dimensional computer tomography (4DCT) reflects actual tumor motion during beam-on throughout the course of treatment. Methods and Materials Twenty-three patients who had lung stereotactic body radiation therapy (SBRT) treatments were retrospectively selected. All patients had 4DCT simulation for treatment planning, from which tumor motion ranges were measured (R4DCT). Tumor motion was monitored during treatment using megavoltage (MV) imaging. Tumor motion trajectories were extracted from cine MV images and were used to determine mean and maximum tumor motion range (Mean RMV, Max RMV) throughout entire course of treatment. Comparison and correlations between mean and max RMV and R4DCT were calculated. Results On average, an insignificant difference was found between mean RMV and R4DCT (P = .67, mean [±SD] difference=−0.7 [±1.6] mm); meanwhile a significant difference was found between Max RMV and R4DCT (P = .03, mean [± SD] difference=1.9 [±1.6] mm). The difference between RMV and R4DCT was found inversely proportional to R4DCT (Y = −0.4X + 0.6, r=0.76). Max RMV was greater than R4DCT in all patients; difference between the 2 showed no correlation with R4DCT (Y = −0.02X + 1.9, r=0.05). Correlation between Mean RMV and R4DCT and between Max RMV and R4DCT can be expressed as Y=0.7X (r = 0.88) and Y=0.8X (r = 0.50), respectively. The same analysis performed on tumors that moved less than 5 mm from 4DCT revealed the following correlations: Y=1.3X (r = 0.83) and Y=1.7X (r = 0.49). Conclusions Tumor motion measured from 4DCT approximates the overall average tumor motion range, but consistently underestimates the overall maximum tumor motion range. These findings may lead to a potential strategy for managing uncertainties of 4DCT in the application of lung SBRT.
Responses of Lyngbya wollei to algaecide exposures and a risk characterization associated with their use

To make informed decisions regarding management of noxious algal growths, water resource managers require information on responses of target and non-target species to algaecide exposures. Periodic treatments of Phycomycin®-SCP (sodium carbonate peroxyhydrate) followed by Algimycin®-PWF (gluconate and citrate chelated copper) to control Lyngbya wollei growths for ten years provided an opportunity for a risk evaluation of treated coves in Lay Lake, AL. Abiotic sediment characteristics (acid soluble copper concentrations, acid volatile sulfides, percent organic matter and cation exchange capacity) and survival of Hyalella azteca and Chironomus dilutus were measured in sediment samples from treated and untreated coves to assess the bioavailability of potential copper-residuals. In laboratory studies to seek a more effective approach for managing the growth of Lyngbya, six algaecide treatments consisting of combinations of copper-based algaecides (Cutrine®-Ultra, Clearigate® and Algimycin®- PWF), a hydrogen peroxide based algaecide (Phycomycin®-SCP) and an adjuvant (Cide-Kick II) were assessed for efficacy in controlling L. wollei sampled from Lay Lake. The most efficient algaecide treatment was determined based on post-treatment algal wet weight and visual observations of responses to exposures. To estimate the margin of safety for non-target organisms, Pimephales promelas was exposed to the most efficacious treatment and a treatment of Phycomycin®-SCP followed by Algimycin®-PWF. Results from sediment experiments demonstrated that there were no measureable copper residuals and no adverse effects on H. azteca and C. dilutus from sediments following ten years of copper-based algaecide treatments. Based on the laboratory results, a treatment of Phycomycin®-SCP at 10.1 mg H2O2/L followed by Cide-Kick II at 0.2 mg/L and Algimycin®- PWF at 0.26 mg Cu/L could control the growth of Lyngbya wollei from Lay Lake, AL and enhance the margin of safety for non-target species (e.g. P. promelas).
Elimination of cdc2 phosphorylation sites in the cdc25 phosphatase blocks initiation of M-phase.

The cdc25 phosphatase is a mitotic inducer that activates p34cdc2 at the G2/M transition by dephosphorylation of Tyr15 in p34cdc2. cdc25 itself is also regulated through periodic changes in its pho...
A semi-automatic TLD reader

Since all of the commercially-available readers are manually operated, measurements with thermoluminescent dosemeters (TLD) are time-consuming and require the undivided attention of the operator for an average of a minimum of one minute per reading. Thus when TLD's are to be used on a large scale, some form of automation is indicated. This note describes an automated TL reader which reads 23 dosemeters in sequence, and prints out the data in digital form upon demand. The reader has been in routine use for over two years and has proved to be dependable and convenient.
TH‐D‐AUD C‐01: Early Blood‐Brain‐Barrier Disruption in Response to RT as a Biomarker for Neurotoxicity

Purpose: Studies of neurocognitive dysfunction after radiation in animals suggest that vascular injury plays a key role. We hypothesized that blood‐brain‐barrier (BBB) disruption in normal appearing cerebral tissue of patients early in the course of fractionated radiation therapy (RT) is a biomarker for delayed neurocognitive dysfunction. Method and Materials: Ten patients with low‐grade glioma, or suprasellar lesion and underwent 3D conformal cranial RT (28–33 fx of 1.8 Gy) participated in a prospective MRI study. Dynamic‐contrast enhanced (DEC) MRI was acquired before, at week 3 and week 6 during the course of, and at 1, 6 and 18 months after the completion of RT. Using the modified Toft model, the contrast transfer constant (K) from the intravascular space to the extravascular extracellular space was estimated. A battery of standardized neuropsychological tests was performed at the same times as the pre‐ and post‐RT MRI. The relationship between the temporal changes in K and the dosimetric parameters was analyzed by a linear mixed model. Correlations between the changes in K and early delayed changes in the neurocognitve functions were analyzed by linear regression.Results: The K values increased significantly in normal appearing tissue regions that received >40 Gy at week 6 during RT (p<0.05), suggesting BBB opening. The elevated K values decreased gradually after RT. The changes in K both during and after RT were significantly correlated with the doses received at the time but the significance decreased from p = 0.0001 at week 3 during RT to 0.03 at 6 months after RT. The changes in K of left frontal lobe at week 3 during RT were significantly negatively correlated with the changes in verbal learning scores at 6 months after RT (p<0.02). Conclusion: Our data suggest early BBB disruption could be a biomarker for delayed neurocognitve function deterioration. Supported by NIHP01CA59827 and R21CA11369901.
A Symmetric Function Generalization of the Chromatic Polynomial of a Graph

Abstract For a finite graph G with d vertices we define a homogeneous symmetric function XG of degree d in the variables x1, x2, ... . If we set x1 = ... = xn= 1 and all other xi = 0, then we obtain χG(n), the chromatic polynomial of G evaluated at n. We consider the expansion of XG in terms of various symmetric function bases. The coefficients in these expansions are related to partitions of the vertices into stable subsets, the Mobius function of the lattice of contractions of G, and the structure of the acyclic orientations of G. The coefficients which arise when XG is expanded in terms of elementary symmetric functions are particularly interesting, and for certain graphs are related to the theory of Hecke algebras and Kazhdan-Lusztig polynomials.
Mechanical properties of iron-based bulk metallic glasses

Iron-based bulk metallic glasses (BMGs) are characterized by high fracture strengths and elastic moduli, with some exhibiting fracture strengths near 4 GPa, 2–3 times those of conventional high-strength steels. Among the Fe-based BMGs, the non-ferromagnetic ones, designated “non-ferromagnetic amorphous steel alloys” by two of the present authors [S.J. Poon et al.: Appl. Phys. Lett. 83, 1131 (2003)], have glass-forming ability high enough to form single-phase glassy rods with diameters reaching 16 mm. Fe-based BMGs designed for structural applications must exhibit some plasticity under compression. However, the role of alloy composition on plastic and brittle failures in metallic glasses is largely unknown. In view of a recently observed correlation that exists between plasticity and Poisson’s ratio for BMGs, compositional effects on plasticity and elastic properties in amorphous steels were investigated. For the new amorphous steels, fracture strengths as high as 4.4 GPa and plastic strains reaching ∼0.8% were measured. Plastic failure instead of brittle failure was observed as the Poisson’s ratio approached 0.32 from below. Investigation of the relationship between the elastic moduli of the alloys and those of the alloying elements revealed that interatomic interactions in addition to the elastic moduli of the alloying elements must be considered in designing ductile Fe-based BMGs. The prospects for attaining high fracture toughness in Fe-based BMGs are discussed in this article.
Re-engineering healthcare: computer tools support the definition and analysis of work at the Vanderbilt University Hospital and Clinic

In November 1993 The Vanderbilt University Hospital and Clinic (VUH/TVC) convened a 10-member Collaborative Organization Design (COD) team comprised of a multi-disciplinary team representing a diagonal slice through the organization. This team, lead by Gelinas * James, Inc. a consulting firm specializing in restructuring, was charged to develop, recommend, and implement a new organizational design that would promote stronger patient focus, increased efficiency, and lower cost. The COD process is structured to inspire and enable employees to rebuild their organization to respond to the challenges and opportunities that exist within their environment, to customer needs, and their own aspirations. This manuscript presents an overview of (1) the computer tools developed and/or employed to support the re-engineering process, and (2) the findings obtained as the work of patient care was defined and analyzed at VUH/TVC.
Mexican American Referenda Voting on Urban Economic Development and Governmental Structure Issues: Research Note

The voting behavior of Mexican Americans is compared to that of Anglos on several referenda issues in one city. The referenda votes focus on several issues that theory suggests are central to understanding contemporaryAmerican urban politics: economic development and human services, and governmental structure. The analysis brings together issues of ethnicity, public policy, and governmental structure. The contention that economic development is almost universally popular is not strongly supported by the findings. This is a significant finding relative to an influential theory, one that has not been extensively tested. Another significant finding is the apparent substantial difference between Mexican Americans and Anglos regarding some major urban public policy issues, such as economic development and human services.
The Role of the Poly(ADP-ribose) Polymerase Tankyrase1 in Telomere Length Control by the TRF1 Component of the Shelterin Complex

Tankyrase1 is a multifunctional poly(ADP-ribose) polymerase that can localize to telomeres through its interaction with the shelterin component TRF1. Tankyrase1 poly(ADP-ribosyl)ates TRF1 in vitro, and its nuclear overexpression leads to loss of TRF1 and telomere elongation, suggesting that tankyrase1 is a positive regulator of telomere length. In agreement with this proposal, we show that tankyrase1 RNA interference results in telomere shortening proportional to the level of knockdown. Furthermore, we show that a tankyrase1-resistant form of TRF1 enforced normal telomere length control, indicating that tankyrase1 is not required downstream of TRF1 in this pathway. Thus, in human cells, tankyrase1 appears to act upstream of TRF1, promoting telomere elongation through the removal of TRF1. This pathway appears absent from mouse cells. We show that murine TRF1, which lacks the canonical tankyrase1-binding site, is not a substrate for tankyrase1 poly(ADP-ribosyl)sylation in vitro. Furthermore, overexpression of tankyrase1 in mouse nuclei did not remove TRF1 from telomeres and had no detectable effect on other components of mouse shelterin. We propose that the tankyrase1-controlled telomere extension is a human-specific elaboration that allows additional control over telomere length in telomerase positive cells.
Effect of Impurity Scattering on the Magnetoresistance of n-Type Germanium

Observations in $n$-type germanium show a decrease in the anisotropy of the magnetoresistance with increased ionized-impurity content and with decreased temperature. Although similar to what is expected due to ionized-impurity scattering, the details of the variation do not agree with calculations assuming anisotropic impurity scattering. Deviations from the magnetoresistance symmetry conditions are observed for crystals with electron concentration $ng4\ifmmode\times\else\texttimes\fi{}{10}^{15}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ at 77\ifmmode^\circ\else\textdegree\fi{}K.
Menarchal status and calf circumference predict calcaneal ultrasound measurements in girls.

Purpose The purpose of this study was to predict calcaneal QUS measurements in healthy adolescent females as a function of anthropometric measures, pubertal stage and menarchal status.
Human T-cell leukemia virus type 1 Tax attenuates γ -irradiation-induced apoptosis through physical interaction with Chk2

Checkpoint kinase 2 (Chk2) is known to mediate diverse cellular responses to genotoxic stress. The fundamental role of Chk2 is to regulate the network of genome-surveillance pathways that coordinate cell-cycle progression with DNA repair and cell survival or death. Defects in Chk2 contribute to the development of both hereditary and sporadic human cancers. We now present evidence that the human T-cell leukemia virus type-1 (HTLV-1) Tax protein directly interacts with Chk2 and the kinase activity of Chk2 is inhibited by Tax. The physical interaction of Chk2 and Tax was observed by co-immunoprecipitation assays in HTLV-1-infected T cells (C81) as well as GST pull-down assays using purified proteins. Binding and kinase activity inhibition studies with Tax deletion mutants indicated that at least two domains of Tax mediate the interaction with Chk2. We have analysed the functional consequence of de novo expression of Tax upon the cellular DNA-damage-induced apoptosis, which is mediated by Chk2. Using transient transfection and TUNEL assay, we found that γ-irradiation-induced apoptosis was decreased in 293T and HCT-116 (p53−/−) cells expressing HTLV-1 Tax. Our studies demonstrate an important potential target of Tax in cellular transformation.
J. S. Mill on education

Mill may be said either to have written rather little on education or to have written a very great deal. He himself distinguished between a ‘narrow’ and a ‘wider’ sense of education, the former limited to what happens in formal educational settings, the latter embracing all the influences that make us who and what we are. He wrote rather little on the former and a great deal on the latter, ranging from the account of his own education in his Autobiography to his discussion of ‘ethology’ in System of logic, and his thoughts about the educative effects of political institutions in Representative government. Liberty and The subjection of women are tracts on the role of both wider and narrower education in liberating us from the constraints of custom and securing equality between the sexes. They still have much to say to a 21st-century audience.
Should Habitat Trading Be Based on Mitigation Ratios Derived from Landscape Indices? A Model-Based Analysis of Compensatory Restoration Options for the Red-Cockaded Woodpecker

Many species of conservation concern are spatially structured and require dispersal to be persistent. For such species, altering the distribution of suitable habitats on the landscape can affect population dynamics in ways that are difficult to predict from simple models. We argue that for such species, individual-based and spatially explicit population models (SEPMs) should be used to determine appropriate levels of off-site restoration to compensate for on-site loss of ecologic resources. Such approaches are necessary when interactions between biologic processes occur at different spatial scales (i.e., local [recruitment] and landscape [migration]). The sites of restoration and habitat loss may be linked to each other, but, more importantly, they may be linked to other resources in the landscape by regional biologic processes, primarily migration. The common management approach for determining appropriate levels of off-site restoration is to derive mitigation ratios based on best professional judgment or pre-existing data. Mitigation ratios assume that the ecologic benefits at the site of restoration are independent of the ecologic costs at the site of habitat loss. Using an SEPM for endangered red-cockaded woodpeckers, we show that the spatial configuration of habitat restoration can simultaneously influence both the rate of recruitment within breeding groups and the rate of migration among groups, implying that simple mitigation ratios may be inadequate.
Accumulation of proteolytic fragments of mutant presenilin 1 and accelerated amyloid deposition are co-regulated in transgenic mice

The activities of presenilin 1 (PS1) and 2 modulate the proteolytic processing of amyloid precursor proteins to produce Abeta1-42, and mutations in these proteins are associated with an accelerated rate of Abeta deposition. PS1 and PS2 themselves are subject to a highly-regulated endoproteolytic cleavage to generate stable 27 kDa N-terminal and 17 kDa C-terminal fragments. Here, we examined the relationship between the regulated cleavage of PS1 and the acceleration of Abeta deposition in transgenic mice that co-express Mo/Hu APPswe and varied levels mutant PS1 (A246E variant). The steady-state levels of the N- and C-terminal fragments of mutant PS1 in mice expressing low levels of mRNA were similar to that of mice expressing high levels of mRNA. Only mice expressing high levels of transgene mRNA accumulated uncleaved full-length protein. In mice co-expressing low levels of PS1A246E mRNA with Mo/Hu APPswe the age of appearance of Abeta deposits was similar to that of mice co-expressing expressing Mo/Hu APPswe with very high levels of mutant PS1. Our findings demonstrate that the levels of accumulated human PS1 N- and C-terminal fragments do not increase in proportion to the level of transgene mRNA and that similarly, the magnitude by which mutant PS1 accelerates the deposition of beta-amyloid is not proportional to the level of transgene expression.
Precision, Not Power

The essence of precision measurement is to investigate elusive physical phenomena by achieving high accuracy, or observing very weak events, or both. This normally requires a system sufficiently simple that quantitative comparisons with theory are possible. On page 196 of this issue van Rooij et al. ( 1 ) present results of a study that encompasses all of these elements. They report on a precise measurement of laser-driven transitions between the singlet and triplet metastable excited states of atomic helium, 2 1S and 2 3S, a transition so strongly forbidden by spin and parity selection rules that even 10 years ago, its excitation would have been regarded as impossible. The transition is weaker by 14 orders of magnitude than a typical fully allowed electric dipole transition (see the figure) ( 2 ) and is one of the weakest optical transitions to be measured with accuracy. This feat is accomplished not by resorting to high laser powers but by using modest powers in conjunction with long interaction times and very narrow linewidths.
The muscatine cholesterol family study: Familial aggregation of blood lipids and relationship of lipid levels to age, sex and hormone use☆

The Muscatine Cholesterol Family Study includes data on first, second and third-degree relatives of school children who have the following cholesterol levels: above the 95th percentile in two consecutive school screens, N = 53; below the 5th percentile twice, N = 45; and a random sample between the 5th and 95th percentiles twice, N = 44. For males and females not taking estrogen the relationship of cholesterol to age was the same in high, middle, and low groups, although the overall level differed. For females taking estrogen, cholesterol levels rose more quickly with age in the high group as compared to the middle and low groups. The triglyceride levels of females taking estrogen is higher at younger ages and shows no significant change with increasing age. Among first degree relatives, the cholesterol correlations are between 0.25 and 0.30. Correlations in relatives of the middle group probands are higher than those in relatives of high or low group probands, but not significantly so. Correction for ascertainment increases the correlations in the high and low groups. Among second degree relatives cholesterol correlations in all three groups are approximately 0.20. There is negligible cholesterol correlation between spouses in the high and low groups, while the middle group spouse correlation is significantly greater than zero. Categorical analysis suggests the effect of the proband's cholesterol level is seen most upon the cholesterol level of parents, with siblings and second-degree relatives being less similarly affected.
Platelet-activating factor contributes to postischemic vasospasm.

Abstract Background. The purpose of the present study was to determine if platelet-activating factor is an important mediator that produces vasospasm during reperfusion after ischemia in skeletal muscle. Materials and Methods. A vascular isolated cremaster muscle in male Sprague–Dawley rats was coupled with local intraarterial drug infusion as a model to study microcirculation responses to ischemia/reperfusion injury. Arteriole diameters and capillary perfusion were measured using intravital microscopy. Group 1: platelet-activating factor dose response. Group 2: Effects of a cyclooxygenase inhibitor; indomethacin, and a thromboxane synthetase inhibitor, imidazole, on the response to platelet-activating factor. Group 3: Effects of nitric oxide synthesis inhibitor; N ω -nitro- l -arginine methyl ester, on the response to platelet-activating factor. Group 4: Effects of a platelet-activating factor receptor antagonist, CV-3988, indomethacin, and imidazole after 4 h of warm ischemia and reperfusion. Results. Intraarterial infusion of platelet-activating factor produced a dose-related but mild vasoconstriction. Pretreatment with indomethacin or imidazole resulted in significant vasodilation actually emanating from platelet-activating factor infusion. Nitric oxide inhibition (with N ω -nitro- l -arginine methyl ester) enhanced the vasoconstriction produced by platelet-activating factor. Pretreatment with CV-3988, indomethacin, or imidazole significantly attenuated ischemia/reperfusion-induced vasospasm and capillary no-reflow in the cremaster muscles. Conclusions. Ischemia/reperfusion-induced vasoconstriction is at least in part mediated by platelet-activating factor and thromboxane A 2 .
Systematics in pion double charge exchange

The initial results of a systematic investigation into pion-double-charge-exchange reactions are reported. Data consisting of angular distributions and excitation functions have been measured in an effort to determine the reaction mechanism and understand its implications for nuclear physics. Cross sections are presented for (${\ensuremath{\pi}}^{+}$,${\ensuremath{\pi}}^{\ensuremath{-}}$) reactions on $^{9}\mathrm{Be}$ $^{12,13}\mathrm{C}$, $^{16,18}\mathrm{O}$, $^{24,26}\mathrm{Mg}$, $^{32}\mathrm{S}$, and $^{209}\mathrm{Bi}$. Surprising systematics of the reaction as functions of pion scattering angle and energy, as well as target mass and isospin, are revealed. The data are discussed in terms of two reaction models, one involving a higher-order optical potential and the other involving multiple reaction amplitudes.
One-step redox route to N-Heterocyclic phosphenium ions

One-step reactions of the appropriate N-alkyl-, N-cycloalkyl-, and N-aryl-substituted α-diimines with PI3 afforded >80% yields of the triiodide salts of the following N-heterocyclic phosphenium ions, 3 (R1 = t-Bu; R2 = H); 4 (R1 = 2,6-i-Pr2C6H3; R2 = H), 5 (R1 = Mes; R2 = H), 6 (R1 = 2,6-i-Pr2C6H3; R2 = H), and 7 (R1 = cyclohexyl; R2 = H). Treatment of 3 and 6 with NaB(C6H5)4 resulted in virtually quantitative yields of the corresponding [B(C6H5)4]- salts 8 and 9, respectively. The X-ray crystal structures of 3 and 5−9 were determined.
Relations of the parameters of the I-K distribution for irradiance fluctuations to physical parameters of the turbulence.

By using results from perturbation techniques for weak turbulence and the asymptotic theory for strong turbulence, we develop expressions for the parameters α and ρ of the I–K distribution in terms of the Rytov variance for plane waves σ12=1.23Cn2 k7/6L11/6 and the inner scale of turbulence parameter l0. Comparisons of the resulting scintillation index to experimental data and numerical results from the solution of the fourth-moment equation for 3-D propagation show good agreement.
Planar Cell Polarity: Microtubules Make the Connection with Cilia

Despite decades of research there are still basic aspects of planar cell polarity that are not well understood. Recent work in mouse tracheal epithelial cells links microtubules with both establishing asymmetry as well as responding to this asymmetry to coordinate cellular orientation.
A study on basis conjugate matrices

Abstract The purpose of this paper is to discuss some important ideas to construct a basis conjugate matrix which can be used to solve algebraic eigenvalue equations.
Non deterministic polynomial optimization problems and their approximations

Abstract A unified and general framework for the study of nondeterministic polynomial optimization problems (NPOP) is presented and some properties of NPOP's are investigated. A characterization of NPOP's with regard to their approximability properties is given by proving necessary and sufficient conditions for two approximability schemes. Known approximability results are shown to fit within the general frame developed in the paper. Finally NPOP's are classified and studied with regard to the possibility or impossibility of ‘reducing’ certain types of NPOP's to other types in a sense specified in the text.
Phosphorylation motifs in the nonhelical domains of myosin heavy chain and paramyosin may negatively regulate assembly in Caenorhabditis elegans striated muscle.

We are interested in mechanisms that establish and maintain the highly ordered contractile apparatus of striated muscle. The homologous proteins myosin and paramyosin are the major structural components of thick filaments in invertebrate animals. In Caenorhabditis elegans, both proteins contain a homologous, small nonhelical domain that is known to be phosphorylated in paramyosin. In this report, we show that a proposed phosphorylation motif (S_S_A), which is present in several copies in the nonhelical regions of both myosin and paramyosin, is highly conserved among nematodes. We used in vivo assays to examine the assembly properties of proteins in which one or more motifs were targeted by point mutagenesis or deletion. In all cases, expression of mutant proteins improved the phenotype of the corresponding null mutant animals, but produced variable structural defects, including birefringent aggregates in adults and abnormal localization in embryos. Point mutation, but not deletion, of the myosin A nonhelical tailpiece produced ectopic structures that appeared as masses of jumbled filaments by TEM. Antibody labeling showed that aggregates of either mutant protein did not recruit the endogenous version of the other. Analysis of mutant embryos lacking either paramyosin or myosin A (the essential isoform at the thick filament center) indicated that both wild-type proteins can independently localize and initiate assembly, although the structures produced are abnormal. Our results suggest that muscle cells actively restrict myosin and paramyosin assembly through phosphorylation of the S_S_A motifs and that each protein is regulated independently. © 2010 Wiley-Liss, Inc.
Fullerene doped glasses as solid state optical limiters

We discuss the optical limiting behavior of sol-gel glasses doped with fullerene derivatives. Comparisons to fullerene solutions and thin films are made.
Preparation of Biopolymer Fibers by Electrospinning from Room Temperature Ionic Liquids

Electrospinning is a versatile process used to prepare micro- and nano- sized fibers from various polymers dissolved in volatile solvents. In this report, cellulose and cellulose-heparin composite fibers are prepared from nonvolatile room temperature ionic liquid (RTIL) solvents by electrospinning. RTILs are extracted from the biopolymer fiber after the fiber formation using a cosolvent. Micron to nanometer sized, branched fibers were obtained from 10% (w/w) concentration of polysaccharide biopolymer in RTIL solution with an applied voltage of 15-20 kV. Cellulose-heparin composite fibers showed anticoagulant activity, demonstrating that the bioactivity of heparin remained unaffected even on exposure to a high voltage involved in electrospinning.