cssi/SciSciGPT-SciSciNet huggingface dataset:
Zone of influence of a gas permeable membrane system for delivery of gases to groundwater

[1] One approach for cleaning up aquifers contaminated with organic chemicals is to stimulate biological degradation in situ by addition of gases such as oxygen or hydrogen, which can be introduced into the groundwater using novel hollow-fiber membrane gas transfer systems. In this research, pilot-scale experiments were performed using a 1 m × 2 m × 1 m model sand aquifer to evaluate the effects of membrane system design and operation on the zone of influence of the dissolved gas plume about a vertical narrow bore (2.54 cm inner diameter) well installed in the aquifer. Two membrane systems were evaluated: (1) a membrane module installed directly in the narrow bore slotted well (“in-well” design) which was operated passively and with addition of water pumped from a downgradient extraction well and (2) an “external” module located above the ground surface which was operated in pumped mode only. In addition to the physical experiments a two-dimensional MODFLOW-MT3D simulation model was created using commercial software, calibrated and verified using the experimental data, then used to evaluate additional operational strategies not investigated experimentally. The simulated zones of influence from the calibrated MODFLOW-MT3D model were in good agreement (−1.3 to 14.4%) with experimental observations. Simulations of various well configurations (i.e., locations of extraction and injection wells), pumping rates, and dissolved gas consumption rates suggested that these factors can have a significant effect on the zone of influence and hence the cost of installation and operation of a membrane gas transfer system.
Using mutant cycle analysis to elucidate long-range functional coupling in allosteric receptors.

Functional coupling of residues that are far apart in space is the quintessential property of allosteric receptors. Data from functional studies of allosteric receptors, such as whole-cell dose–response relations, can be used to determine if mutation to a receptor significantly impacts agonist potency. However, the classification of perturbations as primarily impacting binding or allosteric function is more challenging, often requiring detailed kinetic studies. This protocol describes a simple strategy, derived from mutant cycle analysis, for elucidating long-range functional coupling in allosteric receptors (ELFCAR). Introduction of a gain-of-function reporter mutation, followed by a mutant cycle analysis of the readily measured macroscopic EC_(50) values can provide insight into the role of many physically distant targets. This new method should find broad application in determining the functional roles of residues in allosteric receptors.
High efficiency power amplification for microwave and millimeter frequencies

A novel technique for realizing high-efficiency operation of power amplifiers at microwave frequencies is demonstrated. This approach features third-harmonic-peaking Class-F amplifier operation. A novel third-harmonic-peaking circuit using drain-source capacitance in conjunction with a series LC resonant circuit is used to provide maximum power-added efficiency. Simulation data indicate that this amplifier provides an 8% improvement over the conventional Class-B approach at X-band. >
Temperature‐induced water stress in high‐latitude forests in response to natural and anthropogenic warming

The Arctic is particularly sensitive to climate change, but the independent effects of increasing atmospheric CO2 concentration (pCO2 ) and temperature on high-latitude forests are poorly understood. Here, we present a new, annually resolved record of stable carbon isotope (δ(13) C) data determined from Larix cajanderi tree cores collected from far northeastern Siberia in order to investigate the physiological response of these trees to regional warming. The tree-ring record, which extends from 1912 through 1961 (50 years), targets early twentieth-century warming (ETCW), a natural warming event in the 1920s to 1940s that was limited to Northern hemisphere high latitudes. Our data show that net carbon isotope fractionation (Δ(13) C), decreased by 1.7‰ across the ETCW, which is consistent with increased water stress in response to climate warming and dryer soils. To investigate whether this signal is present across the northern boreal forest, we compiled published carbon isotope data from 14 high-latitude sites within Europe, Asia, and North America. The resulting dataset covered the entire twentieth century and spanned both natural ETCW and anthropogenic Late Twentieth-Century Warming (~0.7 °C per decade). After correcting for a ~1‰ increase in Δ(13) C in response to twentieth century pCO2 rise, a significant negative relationship (r = -0.53, P < 0.0001) between the average, annual Δ(13) C values and regional annual temperature anomalies is observed, suggesting a strong control of temperature on the Δ(13) C value of trees growing at high latitudes. We calculate a 17% increase in intrinsic water-use efficiency within these forests across the twentieth century, of which approximately half is attributed to a decrease in stomatal conductance in order to conserve water in response to drying conditions, with the other half being attributed to increasing pCO2 . We conclude that annual tree-ring records from northern high-latitude forests record the effects of climate warming and pCO2 rise across the twentieth century.
The selective hepatic uptake of desialylated peripheral blood mononuclear cells in rabbits

Abstract The effect of desialylation (i.e., neuraminidase treatment) of peripheral blood mononuclear cells on their clearance from the circulation has been studied in rabbits. When autologous 51 Cr-labeled normal and desialylated peripheral blood mononuclear cells were administered intravenously to rabbits 21.9 ± 3.3% (standard deviation) and 37.7 ± 9.2% of the injected radioactivity was recovered from the liver at 1 hr, respectively ( P
Recent Books and Journals Articles in Public Opinion, Survey Methods, and Survey Statistics. 2015 Update

Recent Books and Journals Articles in Public Opinion, Survey Methods, and Survey Statistics. 2015 Update
Testing high brightness LEDs relative to application environment

Application of light emitting diodes is expanding as the luminous output and efficiencies of these devices improve. At the same time, the number of LED package types is increasing, making it challenging to determine the appropriate device for use in lighting product designs. A range of factors should be considered when selecting a LED for an application including color coordinates, luminous efficacy, cost, lumen maintenance, application life, packaging and manufacturability. Additional complexities can be introduced as LED packages become obsolete and replacement parts must be selected. The replacement LED characteristics must be understood and assessed against the parameters of the original device, in order to determine if the change will be relatively simple or will force other end-product changes. While some characteristics are readily measured and compared, other factors, such as lumen maintenance, are difficult to verify. This paper will discuss the characteristics of a LED that should be considered during the design process as well as methods to validate these characteristics, particularly those which are not typically on data sheets or, are critical to the design and warrant additional validation. Particular attention will be given to LED lumen maintenance. While published manufacturer data typically provides temperature versus performance curves, the data may not be useful depending upon the application's operating environment. Models must be created to estimate the LED's junction temperature and degradation curve at the applied temperature in order to develop a more precise life estimate. This paper presents one approach to a LED device life and performance study designed with application environments in mind.
The Culturally-Adapted Early Pathways Program for Young Latino Children in Poverty: A Randomized Controlled Trial

This study used a randomized controlled design with treatment and wait-list conditions to evaluate the efficacy of a culturally adapted version of the Early Pathways program (EP; Fox & Gresl, 2014), an in-home, parent–child therapy program with 137 at-risk Latino children under the age of 6 referred
Reticulon proteins: emerging players in neurodegenerative diseases

Reticulons (RTNs) are a group of integral membrane proteins that have a uniquely conserved C-terminal domain named RHD. In mammalian genomes, transcripts are produced from four genes, rtn1 to rtn4, under the regulation of tissue or cell-type-specific expression. The presence of alternative promoters for gene expression and multiple cryptic splicing sites have resulted in large numbers of genes/proteins that are classified among the reticulon family. Although this family exists in almost all eukaryotes, only the rtn4 gene product, Nogo (RTN4), has gained relatively more in-depth attention. Despite predominant localization in the endoplasmic reticulum, Nogo on the cell surface appears to play a critical role as an inhibitory molecule for axonal growth and regeneration in humans and rodents. Recently, studies have expanded the biological functions of RTNs to other facets including modulating the enzymatic activity of β-secretase in Alzheimer’s disease. In this review, we summarize the accumulated findings concerning the structural and functional aspects of RTNs and speculate on their linkage to the pathogenesis of neurodegenerative diseases.
Experimentally produced gallop rhythm; a preliminary report.

Summary. In order to illustrate the question of the appearance and significance of the gallop rhythm and the third sound gallop, in particular, experimental tests were initiated. Fleisher and Loeb's method was employed for producing myocarditis in rabbits. In about 1/3 of the 30 animals surviving an injection, the gallop rhythm was registrable by means of the phonocardiogram. A closer analysis showed, that this was a case of the third sound gallop (i.e. protodiastolic gallop or rapid filling gallop). In all these instances considerable changes were ascertained in the electrocardiogram and often a marked dilatation of the heart. The patho-anatomical examination, as a rule, revealed a certain degree of hypertrophy and more or less extensive fibrosis in the myocardium.
Algorithms for bridging scale method parameters

Multiple scale simulation methods have been the focus of much attention in recent years. The Bridging Scale method (BSM) of Liu and co-workers was developed as a framework for the dynamic concurrent coupling of atomistics and continua. A key feature of the BSM is a non-reflecting atomistic interfacial condition which relies on a time history integral. In this work, we present a practical review of the relevant theory as well as a new algorithm used in the determination of the kernel function of the time history integral. We also provide a detailed description of the random displacement terms from the interfacial condition, which are required for finite temperature BSM simulations.
Quasi-Steady-State Solutions of Some Population Models

We consider a class of first-order differential equations generalizing the logistic equation of population growth, together with a two-point boundary condition of the form y(0) = η(y(1)) (where y(t) is the size of the population at time t). Thus the population, defined for t ∈ [0, 1], resets itself at the end of the unit time interval to its initial value. If y satisfies the boundary condition and we define Y(t + n) = y(t) for t ∈ [0, 1) and n = 0, 1,…, then Y is a 1-periodic solution of the differential equation (extended to t ∈ [0, ∞ by periodicity) for t ≠ 1, 2,… and Y has a jump of magnitude η(y(1)) − y(0) at t = 1, 2,… . This quasi-steady-state solution corresponds to a population growing or declining on n − 1 < t < n (n = 1, 2,…) and decreasing or increasing impulsively at t = 1, 2,… . Y plays a role for the jump condition y(n + ) = η(y(n − )) analogous to that played by constant solutions to the differential equation with zero jump condition (i.e., y(n + ) = y(n − )). We show, under hypotheses motivated by biological considerations, that a strictly positive solution exists, is unique, and is monotone and continuous in its dependence on η.
Generalized multi‐stage connection networks

This paper develops multi-stage connection networks in which each input terminal can be connected to any number of output terminals. Conditions are given such that these networks are strictly nonblocking or are rearrangeable. Rearrangement algorithms and upper bounds on the required number of moves are developed and it is shown that such networks have fewer cross-points than the product of input and output terminals for a sufficiently large number of input and output terminals.
Leadership Challenges in Addressing Changing Demographics in Schools

Principals who lead demographically diverse schools play an important role in changing the dynamics that often occur in these contexts. Consequently, principals must have the leadership skills to revolutionize teachers’ belief systems. Their energies are consumed with reshaping teachers’ instructional practices and focusing on improving student expectations. Teachers may oppose modification of their teaching practices due to fears of letting go of familiar ways of teaching. The inability to influence teachers will result in continual problems of low expectations, unfair discipline practices, and poor student performance.This study focused on (a) how principals perceived their leadership in responding to their schools’ changing demographics, and (b) the challenges they experienced in attempting to mediate across school groups. Administrators often questioned their leadership capacity in how to mediate racial differences that occurred in their schools as their student demographics changed. Findings revealed...
Theory and observation of highly asymmetric atomic structure in scanning-tunneling-microscopy images of graphite

Images of the (0001) surface of graphite observed in the scanning-tunneling microscope (STM) show a strong asymmetry in the tunneling current between neighboring carbon atoms in the hexagonal ring. The magnitude of this asymmetry is seen to be almost independent of the polarity and to decrease slightly with increasing amplitude of the bais voltage for voltages below 1 V. A theory is developed that explains this anomaly as a purely electronic effect, arising from the symmetry of the states scanned by the STM, which dominates over the topography of graphite. The predicted trends for the bias-voltage dependence of the asymmetry are confirmed experimentally.
Spectral characteristics of the light band on red clover (Trifolium pratense L.)

Abstract One striking characteristic of red clover ( Trifolium pratense L.) is the reflective band across the mid-region of the leaves of many plants. The objective of this study was to determine the nature of this band as related to potential ecological significance. A radiation budget was determined for the light and dark green regions under mid-day sunlight using measurements made with a Li-Cor, LI-1800 spectroradiometer equipped with a microscopic lens. The light region reflected nearly 70% more visible radiation than the dark green region of the leaf; however, this difference amounted only 3.4% of possible radiation reflected by a white barium sulfate standard. There was little difference between the two regions in reflectance from the ultraviolet or infrared. The light region essentially disappeared when subjected to vacuum hydration; this result supported the hypothesis that the scattering of light was due to cell wall-air cavity interfaces. The reflective band, even when broad, does not appear to have a substantial impact on the energy budget of red clover leaves. The nature of the band and its variability within populations lend support to the argument that it is cryptic.
Acoustically segmented photonic crystal fiber for single-frequency high-power laser applications

The Brillouin gain characteristics of a Yb-doped polarization-maintaining photonic crystal fiber possessing a segmented acoustic profile are investigated using a pump-probe technique. The concentrations of fluorine, aluminum, and germanium in two regions of the core were selected, such that the corresponding Brillouin shifts were sufficiently separated to allow for the introduction of a temperature profile along the fiber for further stimulated Brillouin scattering suppression. By using a cutback technique to measure loss, we estimated the Brillouin gain coefficient to be 1.2×10−11 m/W. Despite differences in the concentration levels of dopants between the two segments, there was no evidence of a development of an optical interface. When this fiber was utilized in a counterpumped amplifier configuration, close to 500 W of near-diffraction-limited single-frequency output was obtained.
Free modules over some modular group rings

Let K be a field and G a finite group with subgroup H. We say that (G H) is a K-free pair if whenever M is a finitely generated KG-module whose restriction MH is a free KH-module, then M is a free KG-module. In this paper pairs of groups with this property will be investigated.
Video Data Link Provides Television Pictures In Near Real Time Via Tactical Radio And Satellite Channels

Advances in sophisticated algorithms and parallel VLSI processing have resulted in the capability for near real-time transmission of television pictures (optical and FLIR) via existing telephone lines, tactical radios, and military satellite channels. Concepts have been field demonstrated with production ready engineering development models using transform compression techniques. Preliminary design has been completed for packaging an existing command post version into a 20 pound 1/2 ATR enclosure for use on jeeps, backpacks, RPVs, helicopters, and reconnaissance aircraft. The system will also have a built-in error correction code 2 (ECC) unit, allowing operation via communicatons media exhibiting a bit error rate of 1 X 10-or better. In the past several years, two nearly simultaneous developments show promise of allowing the breakthrough needed to give the operational commander a practical means for obtaining pictorial information from the battlefield. And, he can obtain this information in near real time using available communications channels--his long sought after pictorial force multiplier: • High speed digital integrated circuitry that is affordable, and • An understanding of the practical applications of information theory. High speed digital integrated circuits allow an analog television picture to be nearly instantaneously converted to a digital serial bit stream so that it can be transmitted as rapidly or slowly as desired, depending on the available transmission channel bandwidth. Perhaps more importantly, digitizing the picture allows it to be stored and processed in a number of ways. Most typically, processing is performed to reduce the amount of data that must be transmitted, while still maintaining maximum picture quality. Reducing the amount of data that must be transmitted is important since it allows a narrower bandwidth in the scarce frequency spectrum to be used for transmission of pictures, or if only a narrow bandwidth is available, it takes less time for the picture to be transmitted. This process of reducing the amount of data that must be transmitted to represent a picture is called compression, truncation, or most typically, video compression. Keep in mind that the pictures you see on your home TV are nothing more than a series of still pictures displayed at a rate of 30 frames per second. If you grabbed one of those frames, digitized it, stored it in memory, and then transmitted it at the most rapid rate the bandwidth of your communications channel would allow, you would be using the so-called slow scan techniques.
Resonance enhanced multiphoton ionization of nucleosides by using pulsed-laser desorption in supersonic beam mass spectrometry

Abstract Pulsed-laser desorption is used as a means of volatilizing nucleosides into the gas phase for entrainment into a supersonic jet expansion. These species are then studied in a time-of-flight mass spectrometer by resonance enhanced multiphoton ionization. Using this combination of techniques either relatively soft ionization or controlled fragmentation can be produced. The degree of molecule ion formation is shown to be relatively strong compared to other soft ionization methods such as FAB/MS, SIMS, FD or FI. In addition, the resulting fragmentation produces ions that are characteristic of the structure of the nucleoside. It is further demonstrated that such fragmentation can be used to discrimination between isomeric nucleosides and also between ribose and deoxyribose sugar groups.
A multiresolution restoration method for cardiac SPECT imaging.

In this study we present a multiresolution based method for restoring cardiac SPECT projections. Original projections were decomposed into a set of sub-band frequency images by using analyzing functions localized in both the space and frequency domain. This representation allows a simple denoising and restoration procedure by discarding high-frequency channels and performing inversion only in low frequencies. The method was evaluated in bull’s eye reconstructions of a realistic cardiac chest phantom with a custom-made liver insert and 99m Tc liver-to-heart activity ratios (LHAR) of 0:1, 1.5:1, 2.5:1, and 3.5:1. The cardiac phantom in free air was used as the reference standard. Reconstructions were performed by filtered backprojection using (1) no correction; (2) restoration without attenuation correction; (3) attenuation correction without restoration; and (4) restoration and attenuation correction. The attenuation correction was carried out with the Chang’s method for one iteration. Results were compared with those obtained using an optimized prereconstruction Metz filter. Quantitative analysis was performed by calculating the normalized chi-square measure and mean±s.d. of bull’s eye counts. In reconstructions with high liver activity ( LHAR >2), attenuation correction without restoration severely distorted the polar maps due to the spillover of liver activity into the inferior myocardial wall. Both restoration methods when combined with an attenuation correction compensated this artifact and yielded uniform polar maps similar to that of the standard reference. There was no visual or quantitative difference between the performance of Metz filtering and multiresolution restoration. However, the main advantage of the multiresolution method is that it states a more concise and straightforward approach to the restoration problem. Multiresolution based methods does not require information about the object image or optimization processes, such as in conventional nuclear medicine restoration filters. In addition, the method is easy to implement using DFT techniques and potentially can be extended to noniterative spatially shift-invariant restorations in SPECT.
Non-natural nucleic acids for synthetic biology

Genetic manipulation is an important facet of synthetic biology but can be complicated by undesired nuclease degradation. Incorporating non-natural nucleic acids into a gene could convey resistance to nucleases and promote expression. The compatibility of non-natural nucleosides with polymerases is reviewed with a focus on results from the past two years. Details are provided about how the different systems could be useful in synthetic biology.
Overcoming obstacles for developing carbon nanotube-based devices

Summary form only given. Carbon nanotubes (CNTs), one of the most popular nanoscale materials, have been investigated intensively over the last decade for many of their potential applications. These studies were largely based on theoretical and experimental results from limited numbers of prototype CNT-based devices including field effect transistors (FETs), electron field emitters, interconnects, sensors, probes, energy storage and energy conversion devices. However, the lack of techniques for controlled mass production of CNT-based nanodevices and the ability to accurately characterize their electronic and optical properties have been the primary obstacles for the realization of CNTs' promising technological applications. It is therefore well recognized by the CNT research community that optimization of nano-electronics such as CNT-FETs requires a comprehensive system of nanometrology. Such a system is critical for understanding the role of the local environment, device architecture and internal structure on CNT-FET performance. Oxygen and water vapor have been shown to impact both the CNT conduction channel and the CNT-electrode interface in significantly different ways. Alterations in carrier type such as p-type to n-type, unipolar to ambipolar and changes in contact resistance can all be correlated to oxygen-induced modulation of the Schottky barrier at the nanotube-electrode interface. Shifts in threshold voltage of CNT-FETs have been attributed to the doping of oxygen adsorbate on the bulk of the CNT. The choice of the electrode material, in terms of work function and oxidation state, can influence device resistance. Defects within the CNT itself can act both as electron/phonon scattering sites as well as bonding sites for various adsorbates. In this report, the author will provide an overview of on-going research of CNTs in her group and introduce several newly developed techniques aimed at mass producing CNT-based devices and accurately characterizing their properties. The electronic and optical characterization of the CNT nanodevices were carried out in a unique microenvironment probe system that was developed in her group, which reveals the impact of different adsorbate species and wavelengths of light on device performance. A recent effort of combining scanning electron microscopy, micro-Raman mapping, UHV probing and numeric simulation for studying the curvature of as-grown single-walled CNT in relation to their electronic properties will also be discussed.
From representations to computations: the evolution of web architectures

REpresentational State Transfer (REST) guided the creation and expansion of the modern web. What began as an internet-scale distributed hypermedia system is now a vast sea of shared and interdependent services. However, despite the expressive power of REST, not all of its benefits are consistently realized by working systems. To resolve the dissonance between the promise of REST and the reality of fielded systems, we critically examine numerous web architectures. Our investigation yields a set of extensions to REST, an architectural style called Computational REST (CREST), that not only offers additional design guidance, but pinpoints, in many cases, the root cause of the apparent dissonance between style and implementation. Furthermore, CREST explains emerging web architectures (such as mashups) and points to novel computational structures.
The information content of DNA. II.

Abstract The information content of DNA is directly proportional to Shannon's redundancy which is composed of two parts. This suggests the hypothesis that DNA molecules with higher redundancy of optimum composition may have lower probability of error. The meaning of redundant DNA molecules now being observed, species specific selection of degenerate codons, and correlations of oncogenicity with redundant DNA sequences are all discussed in terms of this hypothesis.
The isotopic composition of strontium in non‐marine carbonate rocks: the Flagstaff Formation of Utah*

The isotopic composition of strontium in surface water in continental basins is determined primarily by the geology of the basin and to a lesser extent by climatic conditions. Consequently, the 87Sr/86Sr ratios of brines in such basins can change only as a result of changes in the geology or climate. This principle of isotope geology was studied by analysis of a suite of non-marine carbonate rocks from the Flagstaff Formation (Palaeocene-Eocene) of Utah. The samples were collected from a section in Fairview Canyon of Sanpete County. They include both limestone and dolomite and were selected to have low non-carbonate residues. The concentrations of strontium in calcites averages 383 ± 128 p.p.m., while those of dolomites increase from 354 ± 74 p.p.m. in the lower 43 m of section to a maximum of 2259 p.p.m. higher up. The increase in the strontium content of dolomite is interpreted as evidence for a change from steady-state to progressively more evaporitic conditions. Two dolomites have isotopic compositions of oxygen expressed as δ18O = -2.75‰ (relative to the PDB standard) and are enriched in 18O relative to two calcites whose average δ18O value is -9.9‰. The 87Sr/86Sr ratios of the carbonate minerals range from 0.70890 to 0.71260. These values are clearly greater than the 87Sr/86Sr ratio of marine carbonates of Early Eocene age which is 0.70744. The variation of the 87Sr/86Sr ratio in this section of the Flagstaff Formation is real and reflects the occurrence of geological events which changed the isotopic composition of Sr entering Lake Flagstaff. The non-carbonate fractions of six carbonate rocks and one sandstone fit a straight line on the strontium mixing diagram in co-ordinates of initial 87Sr/86Sr and 1/Sr concentration. These results suggest that the isotopic composition of strontium in Lake Flagstaff may have been modulated by periodic input of volcanogenic detritus of felsic composition.
Pubertal Timing and Depressive Symptoms in Early Adolescents: The Roles of Romantic Competence and Romantic Experiences

In spite of the large literature supporting the link between early pubertal timing and depression in adolescent girls, there are some exceptions. This suggests that there may be factors that interact with pubertal timing, increasing risk for depression in some girls, but not others. This study examined two such factors, romantic competence and romantic experiences, and their role in the cross-sectional and longitudinal associations between pubertal timing and depressive symptoms among 83 early adolescent females (89% Caucasian). For on-time maturing girls (but not for early- or late-), lower levels of competence were associated with higher levels of depressive symptoms concurrently, but not longitudinally. In addition, for on-time maturing girls, more romantic experiences were associated with higher levels of depressive symptoms both concurrently and longitudinally. The discussion focused on the need for greater conceptual and empirical clarity regarding the pubertal timing-depression association and its potential moderators.
Uncovering the gap, Δ(ω): Measurement of the Re(σS/σN) in superconducting Tl2Ba2CaCu2O8

Abstract We report measurements of both the normal-state reflectance and the superconducting- to normal-state reflectance ratio of a thin film sample of Tl 2 Ba 2 CaCu 2 O 8 at near-normal incidence for photon energies between 0.09 and 4.5 eV. From these data we have obtained the real part of the superconducting- to normal-state optical conductivity ratio, Re(σ S /σ N ). This quantity can be related directly to structure in Δ(ω) without the need to invoke Eliashberg theory. We find structure in Δ(ω) for superconducting Tl 2 Ba 2 CaCu 2 O 8 at low-energy, presumably due to electron-phonon coupling, and additional structure at approximately 1.2 eV and 1.7eV which we attribute to an electronic component of the pairing interaction in this material.
In a battle between parental chromosomes, a failure to reload

What can go wrong after an egg is fertilized by sperm from a different species? One of the most intriguing outcomes to the chromosome biologist is uniparental genome elimination. In this phenomenon, one of the parental chromosome sets is completely lost during embryonic cell divisions, creating sterile haploid offspring (1). Uniparental genome elimination occurs in diverse taxa, including several distantly related plant species and even in fish (1, 2). The mechanism by which chromosomes from one parent are selectively discarded has been studied cytologically in crosses between different grass species. However, these experiments have not revealed what is defective about the eliminated genome in a hybrid. In PNAS, Sanei et al. (3) make a major breakthrough by showing that missegregated chromosomes in a classic barley interspecies cross (Hordeum vulgare × Hordeum bulbosum) fail to assemble kinetochores, the microtubule attachment sites that mediate chromosome inheritance.
Nitrate reductase activity and the speciation of selenium at the mouth of Chesapeake bay

Nitrate reductase activity and the concentrations of selenite and selenate were monitored for six months at the mouth of Chesapeake Bay (USA). A positive correlation was found between nitrate reductase activity and the concentration of selenite, suggesting that selenite may be formed in coastal waters and nitrate reductase may be involved in the process.
Impurities and quasi-one-dimensional transport in a d-wave superconductor.

Impurity scattering in the unitary limit produces low energy quasiparticles with anisotropic spectrum in a two-dimensional $d$-wave superconductor. We describe a new {\em quasi-one-dimensional } limit of the quasiparticle scattering, which might occur in a superconductor with short coherence length and with {\em finite} impurity potential range. The dc conductivity in a $d$-wave superconductor is predicted to be proportional to the normal state scattering rate and is impurity-{\em dependent}. We show that the {\em quasi-one-dimensional } regime occurs in high-$T_c$ superconductors at low temperatures $T\lesssim 10$~K. We argue that the impurities produce weak localization, in the {\em orthogonal } universality class, of the quasiparticles in a $d$-wave superconductor.
A Study of the Forces Involved in the Incorporation of L‐Methionine into Soy Protein by the One‐Step Plastein‐Like Process

Ultrafiltration was used to study the forces involved in the incorporation of methionine into soy protein. Various solvents were used to determine the extent of noncovalent binding. When analyzed with 0.2M citric acid, 60% of the methionine was incorporated into the soy protein. However, when analyzed with 8M Guanidine HCl and 3M KSCN the incorporation was only 20 and 13%, respectively. This reduction in percent incorporation of methionine by protein denaturants indicates that it was not incorporated by covalent bonds. Incorporation is probably due to hydrophobic attraction of the side chain of methionine with apolar regions in the protein.
Adhesion and coalescence of ductile metal surfaces and nanoparticles

Much more is known about material failure, such as fracture and crack propagation, than the reverse effect of material formation, i.e., how bulk materials form or consolidate during material processing or crack healing. Using the Surface Forces Apparatus, optical interferometry, optical and scanning probe microscopy, and x-ray diffraction, we have studied how gold and platinum films sinter or cold-weld at the nano-scale to form continuous bulk films when two initially rough surfaces composed of nanometer-scale asperities are pressed together. We find that coalescence of these ductile materials occurs abruptly, like a first order phase transition, once a critical local pressure or interparticle separation is reached. Simple thermodynamic and kinetic considerations suggest that it may be a more general phenomenon for ductile materials interacting at the nano-scale. We also make some qualitative comparisons with the very different behavior observed with hard, brittle materials.
Effect of actinomycin D‐containing lipid vesicles on murine renal adenocarcinoma

Forty Balb C/CR mice inoculated with renal cell adenocarcinoma were divided into five groups. Group A (seven animals) received phosphate buffered saline intraperitoneally; group B (seven animals) received free actinomycin D 300 microgram/kg IP; group C (nine animals) received lipid vesicles containing actinomycin D 300 microgram/kg IP; group D (eight animals) received a mixture of free actinomycin D 300 microgram/kg and empty lipid vesicles IP. The median survival of group A was 32 days, of group B 30 days, of group C 45.2 days, of group D 54 days, and of group E 42 days. It is suggested that giving the mixture of the drug and the lipid vesicles produces a balance similar to that found in a vesicle solution containing the actinomycin D. It is also suggested that liposomes slow the absorption of actinomycin D from the peritoneum.
A comparison of thoracic CT and abdominal CT for the identification of thoracic blunt trauma.

BACKGROUND: In light of current trends to limit radiation exposure and costs, as well as increased traffic safety, computed tomography (CT) may have decreasing value for evaluating patients with blunt trauma. The authors examined the utility of chest x-ray and abdominal CT for identifying clinically significant thoracic blunt trauma. METHODS: In this prospective study, findings on thoracic CT, abdominal CT, and chest x-ray from trauma patients were compared to assess injury prevalence and relevance to treatment outcomes. RESULTS: Four hundred forty-four patients were identified, of whom 76% had no findings. Occult findings had significantly lower Injury Severity Scores. All clinically relevant pneumothoraces and most other injuries could be identified without thoracic CT. Two of 3 aortic abnormalities were suspected from chest x-ray. CONCLUSIONS: Clinically significant injuries can be identified with abdominal CT and chest x-ray, safely allowing reductions in radiation exposure, hospital stays, and costs by limiting the use of thoracic CT.
SU-E-J-187: Single-Cell Dosimetric Simulation and Evaluation of Sb-119 for Use as Auger Emitting Nuclide in Targeted Radiotherapy

Purpose: Auger electrons have strong potential for targeted radiotherapy applications because of their relatively short ranged dose profile. 119Sb in particular shows promise as a radioisotope for this application because of its electron emissions with energies near 20 keV. A stochastic characterization of 119Sb and comparison to other auger emitting nuclides has been made to demonstrate this advantage. Methods: A Monte Carlo electron transport code has been written in Python to model the dose to a single cell for activity distributions within the cell membrane, cellular cytoplasm, and nuclear cytoplasm. A spherical geometry has been used, where energy is deposited in shells about the cell center. An extrapolated power fit has been used to model low‐energy electron stopping powers under a continual slowing down approximation. S‐values for dose to the nucleus were calculated from simulation results and were compared to previous analytic results (Thisgaard et. al., Med. Phys. 35, 2008). Finally, the results from this code were compared to other auger electron transport Monte Carlo codes for dosimetric verification. Results: For a cell and nucleus of radius 8μm and 6μm respectively, calculated 119Sb S‐values for activity distributions were 4.10E‐4 Gy/(s Bq) in the cell membrane, 5.93E‐4 Gy/(s Bq) in the cytoplasm, and 2.06E‐3 Gy/(s Bq) within the nucleus. These values are within 13% of S‐values calculated analytically. An explanation for this difference is the omission of CK electrons from this simulation. S‐values calculated for 123I compared with other auger electron transport codes typically agree within a 10% margin. Conclusion: Simulated 119Sb dose distributions have been shown to agree with analytic calculations. The ability of Auger electrons to localize dose to a single cell may lead to a significant dose reduction in healthy tissue. With the development of proper production and chelation techniques, 119Sb shows promise as a radiotherapeutic nuclide. This research was supported by the US Department of Energy: DE‐FG02‐12ER41882
Gas transport properties of poly(3-hydroxyoxetane)

Gas transport properties for poly(3-hydroxyoxetane) (PHO) were measured for five gases at 35°C. While PHO has very low gas permeability coefficients, they are larger than those reported for polyacrylonitrile (PAN), poly(vinyl alcohol) (PVA1) and copolymers of ethylene / vinyl alcohol (EVAL) for all gases tested except He. The permeability coefficients for PHO and EVAL are well correlated with the density of hydroxyl groups along the chain. Extrapolations to PVA1 give values that agree well with those estimated by Salame using the Permachor method. It is suggested that some of the reported experimental values for PVA1 are in error. © 1993 John Wiley & Sons, Inc.
Crustaceans as models for metal metabolism: I. Effects of the molt cycle on Blue Crab Metal Metabolism and Metallothionein

The discontinuous-growth process (i.e. the molt cycle) of crustaceans and their ability to accumulate and regulate metals provide a unique system to study how alterations of specific metabolic processes can affect metal metabolism. We have shown that the extensive physiological and biochemical changes that take place during the molt cycle, particularly after ecdysis, affect metal metabolism in the blue crab, Callinectes sapidus. For example, there are significant changes in the concentrations of copper and zinc in both the hemolymph and the digestive gland. Some of these occur quite rapidly. It has been possible to demonstrate shifts in the cytosolic distribution of copper and zinc in the digestive gland within 90 min of ecdysis that are correlated positively with the degadation of hemocyanin and the liberation of copper. A descriptive model has been developed that describes fluxes of copper and zinc during the molting process.
Application of the Contextual Model to School-Based Counseling: Why Does It Work?.

There is considerable support for the effectiveness of psychotherapies regardless of their individual theoretical underpinnings. They all evidence substantial positive outcomes, particularly if they contain common elements. These include a therapeutic relationship within an appropriate setting, a rationale for why the client is unhappy or distressed and in need of therapy, and procedures for effecting positive change. We interpret these common elements as a process of learning that promotes the client's independence, friendship formation and maintenance, competence, and physical health. © 2009 Wiley Periodicals, Inc.
Introduction to the Knowledge Systems Track

Knowledge systems are those systems developed to facilitate collaboration, knowledge capture, storage, transfer and flow, knowledge use, as well as to foster creativity and innovation. This research track recognizes the evolving nature of work and society to being knowledge based. This year several new mini-tracks were proposed. We were very excited to have such broad interest. Papers presented in the knowledge systems track are far reaching in the subject matter in addition to their appeal to knowledge systems researchers and practitioners. Topics range from knowledge strategies use in indigenous societies to the use of social media to support knowledge initiatives in modern organizations.
A new family of omnidirectional and holonomic wheeled platforms for mobile robots

This paper presents the concepts for a new family of holonomic wheeled platforms that feature full omnidirectionality with simultaneous and independently controlled rotational and translational motion capabilities. The authors first present the "orthogonal-wheels" concept and the two major wheel assemblies on which these platforms are based. The authors then describe how a combination of these assemblies with appropriate control can be used to generate an omnidirectional capability for mobile robot platforms. Several alternative designs are considered, and their respective characteristics with respect to rotational and translational motion control are discussed. The design and control of a prototype platform developed to test and demonstrate the proposed concepts is then described, and experimental results illustrating the full omnidirectionality of the platform with decoupled rotational and translational degrees of freedom are presented. >
Structural Equations Models of Achievement Striving and Impatience—Irritability Dimensions of Type a Behavior and Academic Performance

Abstract The relationships of achievement strivings (AS) and impatience-irritability (II) dimensions of Type A behavior to academic achievement as indicated with the American College Test (ACT), grade point average (GPA), and course grade (CG) were investigated with structural equations models in a collegiate sample of business majors. AS, but not II, was positively associated with academic achievement (as indicated with GPA and CG). AS and II were not associated with ACT, but ACT was positively associated with GPA.
A sediment budget for the southern reach in San Francisco Bay, CA: Implications for habitat restoration

article i nfo The SouthBay Salt Pond RestorationProject isoverseeing the restorationof about 6000 haof formercommercial salt-evaporation ponds to tidal marsh and managed wetlands in the southern reach of San Francisco Bay (SFB). As a result of regional groundwater overdrafts prior to the 1970s, parts of the project area have subsided below sea-level and will require between 29 and 45 million m 3 of sedimentto raise the surfaceof the subsided areas to elevations appropriate for tidal marsh colonization and development. Therefore, a sufficient sediment supply to the far south SFB subembayment is a critical variable for achieving restoration goals. Although both major tributaries to far south SFB have been seasonally gaged for sediment since 2004, the sediment flux at the Dumbarton Narrows, the bayward boundary of far south SFB, has not been quantified until recently. Using daily suspended-sediment flux data from the gages on Guadalupe River and Coyote Creek, combined with continuous suspended-sediment flux data at Dumbarton Narrows, we computed a sediment budget for far south SFB during Water Years 2009-2011. A Monte Carlo approach was used to quantify the uncertainty of the flux estimates. The sediment flux past Dumbarton Narrows from the north dominates the input to the subembayment. However, environmental conditions in the spring can dramatically influence the direction of springtime flux, which appears to be a dominant influence on the net annual flux. It is estimated that up to sev- eral millennia may be required for natural tributary sediments to fill the accommodation space of the subsided former salt ponds, whereas supply from the rest of the bay could fill the space in several centuries. Uncertainty in the measurement of sediment flux is large, in part because small suspended-sediment concentration differences between flood and ebb tides can lead to large differences in total mass exchange. Using Monte Carlo simulations to estimate the random error associated with this uncertainty provides a more statistically rigorous method of quantifying this uncertainty than the more typical "sum of errors" approach. The results of this study reinforce the need for measurement of estuarine sediment fluxes over multiple years (multiple hydrologic conditions) to adequately detail the variability in flux. Additionally, the timing of breaching events for the resto- ration project could be tied to annual hydrologic conditions to capitalize on increased regional sediment supply. Published by Elsevier B.V.
Editorial---Editor-in-Chief Search Committee Report: The Digital Future Is Now

School (University of Pennsylvania) be appointed as the next Editor-in-Chief (EIC) of Marketing Science for a term of three years, beginning January 1, 2008. On September 12, 2007 the INFORMS board unanimously accepted our recommendation. Eric graduated from Harvard with a PhD in Statistics in 1994. After brief stints working as a statistician at the Educational Testing Service (ETS) and at DuPont, and as a lecturer in the Statistics Department at Wharton, he joined the Marketing Department at Wharton in July 1996 as an Assistant Professor. He was appointed the K. P. Chao Professor in 2005. Even within a short period of time, he has built up an impressive record of publications, numbering over 50, in marketing, statistics, and education. He has also won numerous awards for both teaching and research, including being a finalist for the Green Award from the Journal of Marketing Research (2004) and the winner of the 2006 Research Committee of