cssi/SciSciGPT-SciSciNet huggingface dataset:
Optimizing total power of many-core processors considering voltage scaling limit and process variations

Recently, processor manufacturers have integrated more than a hundred cores in a single die to deliver extremely high throughput for highly-parallel, data-intensive applications like physics simulations, 3D-graphics, etc. Meanwhile, excessive power consumption rather than silicon area will limit the performance of many-core processors running the aforementioned applications. In this paper, to optimize the total power of many-core processors, we analyze the impact of 1) the number of cores, 2) parallelism in applications, and 3) supply voltage scaling limit due to on-die memory failure at low supply voltage. Our analysis shows that doubling the number of cores with lower than nominal supply voltage offers the most cost-effective power reduction, resulting in up to 65% less power consumption for highly-parallel applications even when supply voltage scaling is limited to 0.7V. The reduced power, in turn, can be used to improve throughput at higher voltage in power-constrained many-core processors. Furthermore, we extend our analysis to consider within-die core-to-core frequency and leakage variations. When only a subset of cores in a many-core processor are to be chosen to achieve a demanded throughput, moderately fast and leaky cores always provide optimal power consumption. In addition, frequency-island clocking, which allows independent frequency for each core, leads to 7% less power consumption than global clocking, and it prefers the fastest core (among the chosen ones) to process the totally sequential portion of workload.
Technology and Reform-Based Science Education.

Current reforms in science education call for the integration of digital technologies into science teaching, advocating that students learn science content and processes through technology. In this article, we provide practical examples, situated within the literature, of how digital technologies can be used to support the development and implementation of high quality technology-enhanced science lessons. Classroom applications featuring, among others, probeware and electronic voting systems are discussed.
The Drosophila Grp/Chk1 DNA Damage Checkpoint Controls Entry into Anaphase

Abstract It is well established that DNA damage induces checkpoint-mediated interphase arrest in higher eukaryotes, but recent studies demonstrate that DNA damage delays entry into anaphase as well. Damaged DNA in syncytial and gastrulating Drosophila embryos delays the metaphase/anaphase transition [1–6]. In human cultured cells, DNA damage also induces a delay in mitosis [7–9]. However, the mechanism by which DNA damage delays the anaphase onset is controversial. Some studies implicate a DNA damage checkpoint [6, 7, 10], whereas other studies invoke a spindle checkpoint [8]. To resolve this issue, we compared the effects of random DNA breaks induced by X-irradiation to site-specific I-CreI endonuclease-induced chromosome breaks on cell-cycle progression in wild-type and checkpoint-defective Drosophila neuroblasts. We found that both the BubR1 spindle checkpoint pathway and the Grp/Chk1 DNA damage checkpoint pathway are involved in delaying the metaphase/anaphase transition after extensive X-irradiation-induced DNA damage, whereas Grp/Chk1, but not BubR1, is required to delay anaphase onset in the presence of I-CreI-induced double-strand breaks. On the basis of these results, we propose that DNA damage in nonkinetochore regions produces a Grp/Chk1 DNA-damage-checkpoint-mediated delay in the metaphase/anaphase transition.
Clay nanotubes for corrosion inhibitor encapsulation: release control with end stoppers

Halloysite clay tubes of 50 nm diameter and ca. 1000 nm length were analyzed as potential nanocontainers for loading, storage and induced sustained release of chemical agents. Halloysite is a natural aluminosilicate mineral with hollow cylindrical geometry and submicron size. Halloysite nanotubes loaded with the corrosion inhibitor benzotriazole can be admixed into paint to improve its anticorrosion performances as well as the coating tensile strength. Corrosion protection of such coating was evaluated by direct exposure of the coated metal (copper) to highly corrosive media. Loading and release characteristics of benzotriazole from these nanotubes were optimized. Benzotriazole release kinetics correspond to the time needed for the formation of a metal protective layer through copper complexation. For formation of the tube end stoppers, benzotriazole loaded halloysite was exposed to the solution of Cu(II) ions, and kinetics of the stopper complex formation was analyzed. Tunable release of benzotriazole was achieved by controlling the strength of the stopper complexes, and the release time may be varied from ten to hundreds of hours. A possibility for the tube on/off release switch was demonstrated.
A convenient method for the determination of hepatic lauric acid ω-oxidation based on solvent partition

Abstract Assessment of hepatic ω-oxidation of fatty acids by cytochrome P450IV enzymes in toxicology studies can be a means of evaluating test compound effects on peroxisomal proliferation. Routine assay of ω-oxidation, however, requires a simpler method of enzymatic analysis than currently described GC, TLC, or HPLC methods. A method depending upon selective solvent separation of radiolabeled lauric acid from radiolabeled 11- or 12-hydroxydodecanoic acid has been developed. Following enzymatic incubation and addition of 15% methanol to the acidified postincubation mixtures, partitioning with an alkane solvent such as iso-octane, cyclohexane, or n -hexane separated the lauric acid and the hydroxylated products into two immiscible phases. Approximately 97% of the substrate partitioned into the organic phase, and approximately 84% of the hydroxylated products partitioned into the aqueous phase. Subsequent quantitation of the enzymatic activity required only liquid scintillation counting of the aqueous phase. Hepatic homogenates from male rats treated with 0.01, 0.05, 0.125, and 0.25% clofibric acid in the diet for 7 days had enzyme levels 1.3, 6.1, 11.1, or 15.9 times control values, respectively, when assayed by a conventional TCL method, and 1.3, 5.3, 12.3, or 15.3 times control values when assayed by the solvent partition method. The data indicate that the partition method demonstrates comparable sensitivity and better precision and linearity than a more conventional TLC method when induction of hepatic microsomal enzymes in rats is studied.
Atmospheric Gas Absorption at DF Laser Wavelengths.

The absorption of twenty-four DF laser wavelengths ranging from 3.6128 μm P1(6) to 4.0464 μm P3(11) was measured for CH4, N2O, CO2, and HDO vapor. Total absorption was calculated for the lines for each of these absorbing gases and for the N2 and H2O continua independently and collectively for two representative transmission paths (midlatitude summer model); i.e., a vertical path from sea level to the edge of the atmosphere containing 2.93 cm precipitable water and a horizontal 8.0-km path at sea level at 14.2-Torr water vapor partial pressure (11.2 cm precipitable water). Transmission was >90% for twelve lines in the vertical path and >65% for thirteen lines in the horizontal path. A comparison of the measured absorption coefficients was made with calculated values of McClatchey and Selby for seventeen lines. Good agreement was obtained with most lines, the worst within a factor ~2 of predicted values.
Abstract 4145: “Real-time” monitoring of oncolytic viral delivery to solid tumors using contrast-enhanced computed tomography

RATIONALE: The inability to deliver viruses homogeneously throughout solid tumors is a universal obstacle encountered in oncolytic virotherapy. The initial intratumoral viral dispersion volume is a critical determinant of virotherapy efficacy, and depends not only on the number of infected cells, but also on the spatial distribution of the infected cells. In this study, we determined the feasibility and usefulness of monitoring the initial intratumoral delivery of oncolytic viruses to solid tumors using contrast-enhanced computed tomography (CT). EXPERIMENTAL PROCEDURES: Human BxPC-3 pancreatic tumor xenografts were established in nude mice. An engineered oncolytic measles virus expressing the sodium iodide symporter reporter (MV-NIS) was mixed with a 1:10 dilution of Omnipaque-300 contrast material and injected directly into mouse tumors. Mice were imaged with micro-CT immediately pre and post-injection of the virus + Omnipaque solution and on day 3 post-injection with 99mTcO4 micro-SPECT/CT. Tumors were harvested immediately after micro-SPECT/CT imaging for autoradiography and immunistochemistry analysis of radioactivity uptake and viral infection. Linear regression and Spearman correlation analyses were performed to determine the relationship between intratumoral contrast enhancement and subsequent intratumoral viral infection. RESULTS: This dilution of Omnipaque was found to have no effect on viral infectivity or cell viability in vitro, yet was more than adequate for CT imaging of the virus + Omnipaque injectate distribution following intratumoral injection. Ex vivo autoradiography and immunohistochemistry confirmed a strong correlation between intratumoral CT contrast enhancement, SPECT activity, viral infection, and sodium iodide symporter activity. CONCLUSIONS: This injection method is translatable to the clinic and should allow optimization of intratumoral injection in humans. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4145. doi:10.1158/1538-7445.AM2011-4145
A novel method for removing aluminum from spallation-produced82Sr

A novel method is presented for the separation of aluminum from strontium by anion exchange in the hydroxide form. When added in acidic solution, aluminum forms Al(OH) 4 − and is retained while strontium is eluted as the neutral Sr(OH)2. The procedure has been used to purify spallation-produced82Sr for use in the82Sr−82Rb radionuclide generator. It has the advantage that the82Sr solution, which must be at basic pH for generator construction, may be neutralized without introducing cations such as Na+ and NH 4 + . The method may be used to separate any metal which forms an anionic hydroxide from those forming neutral soluble hydroxides.
Social Equity and Ecological Sustainability in HCI: An Ecofeminist Perspective

Despite the recent exponential growth of thought and activity on the topic of sustainability in HCI, important aspects of ecological issues such as the socio-cultural and political remain largely unengaged within the existing discourse. My dissertation research attempts to contribute towards addressing such a gap by focusing on issues of social equity as applicable to ecological issues. My work remains inspired and informed by ecofeminist philosophy in approaching the question 'How are our current notions of sustainability produced?' Such an engagement is an attempt to critically explore, understand, and articulate how existing discursive arrangements and practices lend support to specific goals, commitments, priorities, assumptions, values, roles, responsibilities, and ethical considerations shaping HCI's engagement with ecological issues. This engagement is framed as my dissertation work through the scoping of social equity issues from an ecofeminist perspective.
Numerical modelling of methanol liquid pool fires

The focus of this paper is on numerical modelling of methanol liquid pool fires. A mathematical model is first developed to describe the evaporation and burning of a two-dimensional or axisymmetric pool containing pure liquid methanol. Then, the complete set of unsteady, compressible Navier-Stokes equations for reactive flows are solved in the gas phase to describe the convection of the fuel gases away from the pool surface, diffusion of the gases into the surrounding air and the oxidation of the fuel into product species. Heat transfer into the liquid pool and the metal container through conduction, convection and radiation are modelled by solving a modified form of the energy equation. Clausius–Clapeyron relationships are invoked to model the evaporation rate of a two-dimensional pool of pure liquid methanol. The governing equations along with appropriate boundary and interface conditions are solved using the flux-corrected transport algorithm. Numerical results exhibit a flame structure that compares w...
An Exact Transient Study of Dislocation Emission and its Effects on Dynamic Fracture Initiation

Closed-form transient solutions for the micromechanical process of screw dislocation emission from a stationary crack which is subjected to SH-wave diffraction are presented. The dislocations are allowed to leave the crack edge in arbitrary directions, either singly or in pairs. Imposition of an emission criterion that is both based on the dislocation force concept and is similar to criteria applied to quasi-static emission studies allows expressions for the instants of dislocation emission and arrest and the distance traveled by the dislocation to be obtained. These expressions are studied for their dependence on parameters such as emission direction and speed, and several distinctive dynamic effects are observed. A standard fracture criterion is then imposed, and conditions for determining whether fracture will precede or follow emission are established in terms of real time. Finally, some estimates for the orders of magnitudes of the parameters involved in this micromechanical process are given.
Determination of Absolute ƒ Values from Relative Intensity Measurements for Spectral Lines with Doppler Contour

The experimental determination of absolute intensities for isolated spectral lines or for entire vibration-rotation bands involves formidable experimental difficulties. For this reason it is highly desirable to consider the use of techniques which permit the determination of absolute f values from relative intensity measurements performed by the use of a low resolution spectrograph. It is the purpose of this note to call attention to a useful experimental procedure for spectral lines with Doppler contour and for optical densities which are sufficiently large to assure a nonlinear dependence of intensity on optical density. The method is a generalization of a two-path experiment proposed for emission studies on flames.
High-State Observations of the Eclipsing AM Herculis Object UZ Fornacis

We present high-speed optical photometric observations of the eclipsing AM Her object UZ For that were obtained during 1995 February and October at the Cerro Tololo Inter-American Observatory. On both occasions, UZ For was in its high-luminosity state. In 1995 February, UZ had peak visual magnitude mV ≈ 15.9 ± 0.1 mag, which is roughly 0.5-1 mag brighter than previous reports of its high-state brightness level. In 1995 October, UZ For had peak magnitude mV ≈ 16.75 ± 0.25 mag, which is more similar to earlier reports of its high-state brightness level. The 1995 February light curves and eclipses are different in appearance from those for the lower luminosity states of UZ For reported in the literature. The eclipses are, however, similar to those of other AM Her systems, e.g., they are similar in shape to the eclipses of RE 2107-05 (HU Aqr) and to the ultraviolet eclipses of UZ For. The significance of the last statement is that in both of these systems, the accretion stream contributes a significant fraction of the overall luminosity of the system. In the low-luminosity state of UZ For, the accretion hot spot and the white dwarf photosphere dominate the optical emission. Here, we conclude that in the high-luminosity state, the accretion stream makes a significant contribution (and sometimes dominates) the optical emission from UZ For.
Carbon analysis in fly ash

Abstract A combination of established experimental techniques, i.e. fluorine combustion and mass spectrometry, is presented as a method for the rapid determination of the carbon content in fly ash. Fluorine combustion of fly ash and subsequent gas analysis is shown to agree well with standard loss on ignition analysis for carbon in various fly ashes. Extension of the technique to other elements which form volatile fluorides is mentioned.
Thermoplastic elastomers: fundamentals and applications

Abstract Thermoplastic elastomers are multi-functional polymeric materials that generally possess the processability of thermoplastics and the elasticity of vulcanized rubber. Intrinsic thermoplastic elastomers include microphase-separated block and segmented copolymers containing a soft (low- T g ) species. Recent achievements regarding thermoplastic elastomer block and segmented copolymers in the past year have improved the current understanding of (i) complex nanostructures in unary and multicomponent systems and (ii) the thermally-activated sphere→cylinder and cylinder→gyroid order–order transitions. The use of these materials in organogel, electro-responsive and nanocomposite applications illustrates the diversity and future potential of these technologically important materials.
Connectivity between plasticity and brittle fracture: An overview from nanoindentation studies:

Nanoindentation and scanning probe microscopy techniques applied to deforming thin films, nanospheres, nanowires, and nanocrystalline structures have uncovered new mechanical property phenomena dependent on size scale. This overview addresses several segments — those associated with measurement by nanoindentation, as well as the resulting properties of elasticity and plasticity, and fracture toughness of semi-brittle crystals. Specific to volumes in indentation or compression, it is shown that both pressure and scale effects can become dominant for both elasticity and plasticity at sizes less than 100nm. A strong inverse relationship between yield strength and activation volume for both single crystal and nanocrystalline structures is reviewed. Equally strong is a relationship between fracture toughness, the number of shielding dislocations accommodating indentation prior to fracture, and the basic mechanical and physical properties of semi-brittle solids. The link between fracture toughness and plasticit...
A robust periodogram for high-resolution spectral analysis

Periodogram is an important tool for analyzing time series of mixed spectra that can be decomposed as sinusoids plus noise. While effective in many situations, the ordinary periodogram has two major shortcomings: it cannot resolve sinusoids whose frequencies are separated by less than 1 cycle per unit time; it does not possess sufficient robustness against heavy-tailed noise such as outliers. An alternative periodogram is introduced in this article with the aim of improving the frequency resolution as well as the robustness of the ordinary periodogram. The new periodogram, called bivariate @?"1-periodogram, is derived from the maximum likelihood method of multiple frequency estimation under the assumption of Laplace white noise. The desired high-resolution and robustness property of the bivariate @?"1-periodogram is confirmed by simulation studies. Superior statistical efficiency over alternative methods is also demonstrated.
Ethanol gas sensing properties of SnO2-based thin-film sensors prepared by the sol-gel process

Abstract SnO2 thin-film gas sensors containing La2O2 and Pt were prepared by the sol-gel process. The films were sensitive to ethanol gas as demonstrated by a change in electrical conductivity. The sensitivity was markedly promoted by loading with La 2 O 3 Pt and increasing film thickness. The response time increased with the amount of La2O3 and film thickness. The response time was in the range of 40–70 s at 300 °C and could be decreased to 35 s by loading with Pt. The doubly-loaded film sensors, Pt-La2O3-SnO2, displayed enhanced ethanol gas sensing properties.
Prevalence of the fragile X syndrome in African-Americans.

Since the development of a molecular diagnosis for the fragile X syndrome in the early 1990s, several population-based studies in Caucasians of mostly northern European descent have established that the prevalence is probably between one in 6,000 to one in 4,000 males in the general population. Reports of increased or decreased prevalence of the fragile X syndrome exist for a few other world populations; however, many of these are small and not population-based. We present here the final results of a 4-year study in the metropolitan area of Atlanta, Georgia, establishing the prevalence of the fragile X syndrome and the frequency of CGG repeat variants in a large Caucasian and African-American population. Results demonstrate that one-quarter to one-third of the children identified with the fragile X syndrome attending Atlanta public schools are not diagnosed before the age of 10 years. Also, a revised prevalence for the syndrome revealed a higher point estimate for African-American males (1/2,545; 95% CI: 1/5,208–1/1,289) than reported previously, although confidence intervals include the prevalence estimated for Caucasians from this (1/3,717; 95% CI: 1/7,692–1/1,869) and other studies. Further population-based studies in diverse populations are necessary to explore the possibility that the prevalence of the fragile X syndrome differs among world populations. © 2002 Wiley-Liss, Inc.
Does Doppler detection of asymptomatic embolization predict stroke risk in symptomatic carotid artery stenosis

Does Doppler detection of asymptomatic embolization predict stroke risk in symptomatic carotid artery stenosis?
Measuring Arterial Oxygenation in a High Altitude Field Environment: Comparing Portable Pulse Oximetry With Blood Gas Analysis

Objective High altitude environments present unique medical treatment challenges. Medical providers often use small portable pulse oximetry devices to help guide their clinical decision making. A significant body of high altitude research is based on the use of these devices to monitor hypoxia, yet there is a paucity of evidence that these devices are accurate in these environments. We studied whether these devices perform accurately and reliably under true mountain conditions. Methods Healthy unacclimatized active-duty military volunteers participating in mountain warfare training at 2100 m (6900 feet) above sea level were evaluated with several different pulse oximetry devices while in a cold weather, high altitude field environment and then had arterial blood gases (ABG) drawn using an i-STAT for comparison. The pulse oximeter readings were compared with the gold standard ABG readings. Results A total of 49 individuals completed the study. There was no statistically significant difference between any of the devices and the gold standard of ABG. The best performing device was the PalmSAT (PS) 8000SM finger probe with a mean difference of 2.17% and SD of 2.56 (95% CI, 1.42% to 2.92%). In decreasing order of performance were the PS 8000AA finger probe (mean ± SD, 2.54% ± 2.68%; 95% CI, 1.76% to 3.32%), the PS 8000Q ear probe (2.47% ± 4.36%; 95% CI, 1.21% to 3.75%), the Nonin Onyx 9500 (3.29% ± 3.12%; 95% CI, 2.39% to 4.20%), and finally the PS 8000R forehead reflectance sensor (5.15% ± 2.97%; 95% CI, 4.28% to 6.01%). Conclusions Based on the results of this study, results of the newer portable pulse oximeters appear to be closely correlated to that of the ABG measurements when tested in true mountain conditions.
The Consequences of the Criminal Justice Pipeline on Black and Latino Masculinity

Analyses of the criminal justice system have revealed the racialized nature of crime and punishment in the United States. We know little, however, about how race, crime, and punishment are also experienced as gendered phenomena by marginalized adolescent males. Drawing from ethnographic observations and in-depth interviews, the author proposes that important insights about crime, race, and gender are gained by analyzing the experiences of adolescent males as they navigate through the criminal justice pipeline. Thus, the author examines how policing, incarceration, and probation offer masculinity-making resources that young men use to develop a sense of manhood. This study shows that one of the consequences of enhanced policing, surveillance, and punitive treatment of youth of color is the development of a specific set of gendered practices. One outcome of pervasive criminal justice contact for young black and Latino men is the production of a hypermasculinity that obstructs desistance and social mobility.
Public–Private Partnership in the Development of the Hepatitis B Vaccine in Korea Implications for Developing Countries

National innovation in science and technology depends on many factors. This article presents a case study of the development of hepatitis B vaccine in Korea. It examines the influence of government policy, private sector strategies, intellectual property rights, regulatory frameworks, and programmes of foundations and other donors. The article leads to the conclusion that the most important factor to stimulate the development of products for developing countries is the creation of markets through, for example, the creation of international procurement funds to bridge the gap between real needs and effective demand. Intellectual property rights are often portrayed as a major deterrent to the availability of products for the poor in developing countries, but the hepatitis B case study does not support this assertion. On the national front, the most important inputs of the government are to support biomedical research, to provide transparent means of intellectual property protection and to support the develo...
Time-domain modeling techniques for periodic structures

Novel time-domain modeling techniques for periodic structures are described in this paper. These methods can be used to investigate electromagnetic propagations and scatterings from infinite artificial periodic arrays from arbitrary electromagnetic source illumination and extract the equivalent electric properties of composite structures. Using this method, only a single periodic cell is required in the modeling using finite-difference time-domain method. Several periodic structures are analyzed by this proposed method to testify its computational efficiency in terms of computer memory and computing time.
The polling primitive for hypercube networks

We describe a distributed computing primitive termed polling that is both a means of synchronization and communication in distributed or concurrent systems. The polling operation involves the collection of messages from nodes in an interconnection network, in response to a query. We define the semantics of polling, and present algorithms for implementing the operation on hypercube networks. Time and message lower bounds are presented, and is followed by an analysis of the number of operations performed at each node for each of the different algorithms. We then present empirical results and discuss the characteristics of each algorithm in relation to observed performance.
An Electrochemically Controlled Drug Delivery System Based on a Disulfide-Containing Polymer

AbstractA disulfide bond is known to cleave under certain electrochemical conditions. The authors have developed a model in vitro drug delivery system based on this type of cleavage with possible applications in the transdermal drug delivery field. The system consists of a drug moiety chemically bound by a disulfide bridge to a polymeric backbone, which, once exposed to a predetermined voltage, would cleave the disulfide bond, thereby releasing drug into a soluble medium. The fluorescence of the drug was then monitored to ascertain its concentration. The model drug used was 2-mercaptobenzothiazole, a drug reported to exhibit hypoglycemic activity and combat the effects of experimental diabetes. The polymeric backbone used was poly(mercaptopropylmethyl siloxane). A copolymeric prodrug was synthesized using diethylazodicarboxylate (DAD) as a coupling agent in order to give the resulting mercapto/disulfide copolymer of composition 6:4. The disulfide bridge was electrochemically cleaved using an intermittent ...
On Graph Constructions for LDPC Codes by Quasi-Cyclic Extension

Quasi-cyclic (QC) extension is a recursive graph construction that preserves key design parameters of a “seed” graph, such as the distribution of the degrees of the nodes, while increasing graph size and girth. Algebraic QC extension graphs are described in which automorphisms of the seed graph are purposefully preserved in the extension. The girth of the extension graph will be as least as great as for the seed while the “design rate” of the code is the same. A two-stage QC extension is given for a (3,4) low-density parity-check (LDPC) code to illustrate.
Optimizing Acquisition Parameters in TOF PET Scanners

Noise equivalent counts (NEC) have been used as a measure of PET image quality for many years. As a result, clinical patient dosage and scan times have been determined based upon this figure of merit. Since NEC represents a global measure of signal-to-noise ratio (SNRNEC) in non time-of-flight (Non TOF) PET, we used a lesion detectability metric (channelized hotelling observer signal-to-noise ratio, CHO SNR) to better assess the impact of patient dosage, scan time and time-of-flight (TOF) PET on image quality. Our results indicate that there is a linear relationship between SNRNEC and CHO SNR for most singles rate or activity levels, with an increase in SNRnec due to either increased scan time or increased activity leading to a subsequent increase in CHO SNR. At very high rates, there is an indication that the rate of increase in CHO SNR is lower compared to the gain in SNRNEC as measured on the Gemini TF PET scanner. This reduced gain may be due to some degradation in timing and spatial resolution at high rates. Our results also show that the gain in CHO SNR for a small 20-cm diameter cylinder due to TOF is modest (14%). For a larger 35-cm diameter cylinder we see a greater increase in CHO SNR with TOF (gain of 42%), leading to the possibility of reducing scan time by half, or achieving better lesion detectability over a similar Non TOF scanner.
A Dynein Light Chain Is Essential for the Retrograde Particle Movement of Intraflagellar Transport (IFT)

Several enzymes, including cytoplasmic and flagellar outer arm dynein, share an Mr 8,000 light chain termed LC8. The function of this chain is unknown, but it is highly conserved between a wide variety of organisms. We have identified deletion alleles of the gene (fla14) encoding this protein in Chlamydomonas reinhardtii. These mutants have short, immotile flagella with deficiencies in radial spokes, in the inner and outer arms, and in the beak-like projections in the B tubule of the outer doublet microtubules. Most dramatically, the space between the doublet microtubules and the flagellar membrane contains an unusually high number of rafts, the particles translocated by intraflagellar transport (IFT) (Kozminski, K.G., P.L. Beech, and J.L. Rosenbaum. 1995. J. Cell Biol. 131:1517–1527). IFT is a rapid bidirectional movement of rafts under the flagellar membrane along axonemal microtubules. Anterograde IFT is dependent on a kinesin whereas the motor for retrograde IFT is unknown. Anterograde IFT is normal in the LC8 mutants but retrograde IFT is absent; this undoubtedly accounts for the accumulation of rafts in the flagellum. This is the first mutation shown to specifically affect retrograde IFT; the fact that LC8 loss affects retrograde IFT strongly suggests that cytoplasmic dynein is the motor that drives this process. Concomitant with the accumulation of rafts, LC8 mutants accumulate proteins that are components of the 15-16S IFT complexes (Cole, D.G., D.R. Deiner, A.L. Himelblau, P.L. Beech, J.C. Fuster, and J.L. Rosenbaum. 1998. J. Cell Biol. 141:993–1008), confirming that these complexes are subunits of the rafts. Polystyrene microbeads are still translocated on the surface of the flagella of LC8 mutants, indicating that the motor for flagellar surface motility is different than the motor for retrograde IFT.
Deep oxidation of chlorinated hydrocarbons

Catalysts are described for the low temperature (<275{degrees}C), air oxidation of chlorinated hydrocarbons to CO{sub 2} and HCl. The catalysts are based on Ambersorb{reg_sign} adsorbents as carbonaceous supports. Nearly complete conversion results with the best of a series of catalyst to be discussed. When the hydrogen content of the chlorinated hydrocarbon is less than required for HCl formation, water can be added to satisfy this requirement. Experiments which suggest steps in a more complex total mechanism for deep oxidation are described.
Das Bandenspektrum vom Germaniumoxyd

Das Bandenspektrum von GeO zwischen 2340 und 3300 a wurde mit einem Spektrographen ma\ig hoher Auflosung untersucht. Eine gro\e Zahl bisher unbekannter Banden wurde ausgemessen und das Bandensystem ausgedehnt auf v′=10 und v″=9. Das Auftreten von Isotopen-Schwingungslinien wurde sichergestellt.
Using Pseudogene Database to Identify Lineage-Specific Genes and Pseudogenes in Humans and Chimpanzees

It has been revealed that gene content changes, or gene gains or losses, have played an important role in the evolution of modern humans. As one of the major players accounting for gene content changes, gene pseudogenization is abundant in mammalian genomes, and approximately 20000 pseudogenes have been identified in ape genomes. Therefore, it is an interesting question how to exploit rich information embedded in pseudogenes. Here, I present a bioinformatic pipeline that utilizes a pseudogene database to identify both lineage-specific genes and pseudogenes in humans and chimpanzees. I found 6 human-specific gene gains (HSGs), 1 chimpanzee-specific gene gain, and 4 chimpanzee-specific pseudogenes, most not discovered in previous studies. Further analysis showed that HSGs have been evolving under strong purifying selection and are broadly expressed, indicating strong functional constraint. This study demonstrates the usage of pseudogene information in comparative genomics and suggests that new genes during primate evolution may acquire essential functions in a short time. The pipeline developed here could also be applied to other species.
Ca2+ and Mg2+ Binding Properties of GCAP-1 EVIDENCE THAT Mg2+-BOUND FORM IS THE PHYSIOLOGICAL ACTIVATOR OF PHOTORECEPTOR GUANYLYL CYCLASE

Guanylyl cyclase-activating protein 1 (GCAP-1) is an EF-hand protein that activates retinal guanylyl cyclase (RetGC) in photoreceptors at low free Ca2+ in the light and inhibits it in the dark when Ca2+ concentrations rise. We present the first direct evidence that Mg2+-bound form of GCAP-1, not its cation-free form, is the true activator of RetGC-1 under physiological conditions. Of four EF-hand structures in GCAP-1, three bound Ca2+ ions and could exchange Ca2+ for Mg2+. At concentrations of free Ca2+ and Mg2+ typical for the light-adapted photoreceptors, all three metal-binding EF-hands were predominantly occupied by Mg2, and the presence of bound Mg2+ in GCAP-1 was essential for its ability to stimulate RetGC-1. In the Mg2+-bound form of GCAP-1 all three Trp residues became more exposed to the polar environment compared with its apo form. The replacement of Mg2+ by Ca2+ in the EF-hands 2 and 3 further exposed Trp-21 to the solution in a non-metal-binding EF-hand domain 1 that interacts with RetGC. Contrary to that, replacement of Mg2+ by Ca2+ in the EF-hand 4 moved Trp-94 in the entering α-helix of the EF-hand 3 back to the non-polar environment. Our results demonstrate that Mg2+ regulates GCAP-1 not only by adjusting its Ca2+ sensitivity to the physiological conditions in photoreceptors but also by creating the conformation required for RetGC stimulation.
Towers and maximal chains in Boolean algebras

A tower in a Boolean algebra A is a strictly increasing sequence, of regular length, of elements of A with supremum 1. We consider the following functions:
Femur fractures resulting from stair falls among children: an injury plausibility model.

Background. Stair falls are common among young children and are also common false histories in cases of child abuse. When a child presents with a femur fracture and a stair-fall history, a judgment of plausibility must be made. A lack of objective injury and biomechanical data makes plausibility determination more difficult. Our objective was to characterize key features associated with femur fractures from reported stair falls, to develop a model for assessing injury plausibility (IP). Methods. Children 2 to 36 months of age who presented with a femur fracture from a reported stair fall were studied prospectively. Detailed history recording, examinations, fracture characterization, and injury scene analyses were conducted, and biomechanical measures associated with injury prediction were calculated. With our proposed IP model, all cases were then scored for the detail of history, biomechanical compatibility of fracture morphologic features, time to seeking care, and presence of other injuries. Results. Twenty-nine children were diagnosed with a femur fracture resulting from a reported stair fall. The IP model made a clear distinction between 2 groups, designated plausible and suspicious. Significant differences were observed for the detail of history, biomechanical compatibility of fracture, time to seeking care, presence of other injuries, and total IP scores. In the plausible group, the minimal linear momentum associated with a transverse fracture was almost 10-fold greater than that for spiral or buckle fracture types. Conclusions. This study adds new information to the current body of knowledge regarding injury biomechanics and fractures among children. The IP model provides an objective means of assessing plausibility of reported stair-fall–related femur fractures and identifies key characteristics to facilitate decision-making.
Cutaneous T-cell lymphoma

Cutaneous T-cell lymphomas arise in the skin and are classified by their clinical presentation and cell surface markers. Mycosis fungoides and the Sezary syndrome are the most frequently encountered, followed by the CD30+ lymphoproliferative disorders. The therapy for cutaneous T cell lymphomas (CTCL) depends on the stage of the patient and skin-directed therapy is used for early stages. New targeted therapies for CTCL have become available in the past two decades; however, CTCL remains largely incurable in advanced stages.
Mechanical-Electrical Triggers and Sensors Using Piezoelectric Micowires/Nanowires

We demonstrate a mechanical−electrical trigger using a ZnO piezoelectric fine-wire (PFW) (microwire, nanowire). Once subjected to mechanical impact, a bent PFW creates a voltage drop across its width, with the tensile and compressive surfaces showing positive and negative voltages, respectively. The voltage and current created by the piezoelectric effect could trigger an external electronic system, thus, the impact force/pressure can be detected. The response time of the trigger/sensor is ∼10 ms. The piezoelectric potential across the PFW has a lifetime of ∼100 s, which is long enough for effectively “gating” the transport current along the wire; thus a piezoelectric field effect transistor is possible based on the piezotronic effect.
Purification and Characterization of 1-O-Acylceramide Synthase, a Novel Phospholipase A2 with Transacylase Activity

Abstract A novel pathway for ceramide metabolism, 1-O-acylceramide formation, was previously reported (Abe, A., Shayman, J. A., and Radin, N. S. (1996)J. Biol. Chem. 271, 14383–14389). In this pathway a fatty acid in the sn-2 position of phosphatidylethanolamine or phosphatidylcholine is transferred to the 1-hydroxyl position of ceramide. An enzyme that catalyzes the esterification ofN-acetylsphingosine was purified from the postmitochondrial supernatant of calf brain through consecutive steps, including ammonium sulfate fractionation, DEAE-Sephacel, phenyl-Sepharose, S-Sepharose, Sephadex G-75, concanavalin A-agarose, and heparin-Sepharose chromatography. The molecular mass of the enzyme was determined to be 40 kDa by gel filtration on Sephadex G-75. The enzyme bound to concanavalin A-agarose column was eluted with the buffer containing 500 mm α-methyl-d-mannopyranoside. Further purification by heparin-Sepharose chromatography resulted in separation of two peaks of enzyme activity. Coincidence between the transacylase activity and a stained protein of a molecular mass of 40 kDa was observed, as determined by SDS-polyacrylamide gel electrophoresis and recovery after separation over an acidic native gel. The second peak of activity from the heparin-Sepharose chromatography represented a purification of 193,000-fold. These results are consistent with the enzyme being a glycoprotein of a molecular mass of about 40 kDa with a single polypeptide chain. The purified enzyme had a pH optimum at pH 4.5. The divalent cations Ca2+ and Mg2+enhanced but were not essential for the transacylase activity. Neither activation nor inactivation of the enzyme activity was observed in the presence of 2 mm ATP or 2 mm dithiothreitol. Preincubation of the enzyme with 1 mm N-ethylmaleimide, 1 mm phenylmethylsulfonyl fluoride, or 3.1 μm bromoenol lactone, a potent inhibitor of cytosolic Ca2+-independent phospholipase A2, had no significant effect on the enzyme activity. The enzyme activity was completely abolished in the presence of greater than 773 μm Triton X-100. Partial inhibition of the enzyme activity was observed in the presence of 10–100 μg/ml heparin. In the absence of N-acetylsphingosine, the enzyme acted as a phospholipase A2. These results strongly suggest that 1-O-acylceramide synthase is both a transacylase and a novel phospholipase A2.
A stability bound for systems with periodic output feedback

The authors present a stability bound on additive perturbations in the plant state matrix for systems with piecewise-constant, periodic output feedback. The bound does not require the calculation of the matrix exponential, but instead uses the matrix measure as an upper limit on its norm. This limit and a special norm based on the closed-loop eigenvectors are used to show that if the stability bound is satisfied, all the eigenvalues of the closed-loop discrete-time state matrix have magnitude less than one. It is also shown that if the stability bound is satisfied for two extreme perturbations, then the system is stable for all of the intermediate perturbations. Use of the stability bound is demonstrated by a numerical example. >
INFLUENCE OF POPULATION GROWTH ON CARIBOU HERD IDENTITY, CALVING GROUND FIDELITY, AND BEHAVIOR

A large barren-ground caribou (Rangifer tarandus granti) population (the Bering Seacoast Herd) historically ranged across southwest Alaska. The size of this herd peaked in the early 1860s but declined by the late 1880s. Caribou numbers remained low in southwest Alaska for the next 100 years. Biologists have argued that periodic dispersal has been an important factor in caribou population dynamics. However, others conclude there was no credible evidence that significant interchange between herds has ever occurred in Alaska. Since 1981, we monitored 318 radiocollared caribou and documented dramatic population growth, erratic movements, shifts from traditional ranges, and changes in migratory behavior. We also documented shifts in calving distribution that may contrast with conventional concepts of calving tradition and herd identity. Some biologists have concluded caribou herds can be considered closed populations for management purposes because the number of dispersing caribou is so small that it has no influence on population dynamics. We propose that the current definition of a herd may be appropriate for short-term management; however, over long time frames and large spatial scales, metapopulations may better describe caribou ecology and be more useful in long-term caribou conservation.
Transcriptomics Modeling of the Late-Gestation Fetal Pituitary Response to Transient Hypoxia.

Background The late-gestation fetal sheep responds to hypoxia with physiological, neuroendocrine, and cellular responses that aid in fetal survival. The response of the fetus to hypoxia represents a coordinated effort to maximize oxygen transfer from the mother and minimize wasteful oxygen consumption by the fetus. While there have been many studies aimed at investigating the coordinated physiological and endocrine responses to hypoxia, and while immunohistochemical or in situ hybridization studies have revealed pathways supporting the endocrine function of the pituitary, there is little known about the coordinated cellular response of the pituitary to the hypoxia. Results Thirty min hypoxia (from 17.0±1.7 to 8.0±0.8 mm Hg, followed by 30 min normoxia) upregulated 595 and downregulated 790 genes in fetal pituitary (123-132 days' gestation; term = 147 days). Network inference of up- and down- regulated genes revealed a high degree of functional relatedness amongst the gene sets. Gene ontology analysis revealed upregulation of cellular metabolic processes (e.g., RNA synthesis, response to estrogens) and downregulation of protein phosphorylation, protein metabolism, and mitosis. Genes found to be at the center of the network of upregulated genes included genes important for purine binding and signaling. At the center of the downregulated network were genes involved in mRNA processing, DNA repair, sumoylation, and vesicular trafficking. Transcription factor analysis revealed that both up- and down-regulated gene sets are enriched for control by several transcription factors (e.g., SP1, MAZ, LEF1, NRF1, ELK1, NFAT, E12, PAX4) but not for HIF-1, which is known to be an important controller of genomic responses to hypoxia. Conclusions The multiple analytical approaches used in this study suggests that the acute response to 30 min of transient hypoxia in the late-gestation fetus results in reduced cellular metabolism and a pattern of gene expression that is consistent with cellular oxygen and ATP starvation. In this early time point, we see a vigorous gene response. But, like the hypothalamus, the transcriptomic response is not consistent with mediation by HIF-1. If HIF-1 is a significant controller of gene expression in the fetal pituitary after hypoxia, it must be at a later time.
The Doctoral Thesis of Élie Cartan

Ehe Cartan (1869-1951) was born in Dolomieu, a small village in southwestern France,1 His ancestors were peasants. His father, Joseph, was the village blacksmith. According to Cartan, the course of his life was changed by a visit to the village by the representative of the Departement Isere, to which Dolomeu belongs. During that visit he recommended that Cartan, whose intellectual abilities had already impressed his teachers, try out for a scholarship to a secondary school (lycee). Tutored by one of his teachers, Cartan did well on the scholarship examinations and received a full scholarship to the College de Vienne. He was ten years old at the time. The next ten years were spent in schools far from his home. These included the Lycee de Grenoble, where he spent two years and received first prize in mathematics in a nationwide competition among secondary schools. By 1887, when he entered the distinguished Lycee Janson-de-Sailly, in Paris, his prospects for a successful career in mathematics were thus already good. In November 1888 he entered the Ecole Normale Superieure, in Paris.