cssi/SciSciGPT-SciSciNet huggingface dataset:
Securing ARP From the Ground Up

The basis for all IPv4 network communication is the Address Resolution Protocol (ARP), which maps an IP address to a device's Media Access Control (MAC) identifier. ARP has long been recognized as vulnerable to spoofing and other attacks, and past proposals to secure the protocol have often involved modifying the basic protocol.This paper introduces arpsec, a secure ARP/RARP protocol suite which a) does not require protocol modification, b) enables continual verification of the identity of the tar- get (respondent) machine by introducing an address binding repository derived using a formal logic that bases additions to a host's ARP cache on a set of operational rules and properties, c) utilizes the TPM, a commodity component now present in the vast majority of modern computers, to augment the logic-prover-derived assurance when needed, with TPM-facilitated attestations of system state achieved at viably low processing cost. Using commodity TPMs as our attestation base, we show that arpsec incurs an overhead ranging from 7% to 15.4% over the standard Linux ARP implementation and provides a first step towards a formally secure and trustworthy networking stack.
Atmospheric pressure MALDI-FTMS of normal and chemically modified RNA.

Atmospheric pressure (AP) MALDI has been combined with Fourier transform mass spectrometry (FTMS) to obtain the unambiguous characterization of RNA samples modified by solvent accessibility reagents used in structural studies of RNA and protein-RNA complexes. The formation of cation adducts typical of MS analysis of nucleic acids was effectively reduced by extensive washing of the anionic analytes retained onto the probe surface by strong interactions with a cationic layer of poly(diallyldimethylammonium chloride) (PADMAC). This rapid desalting procedure allowed for the detection of DNA and RNA samples in high femtomole quantities distributed over a 4 × 4 mm sample well. AP MALDI-FTMS was shown to provide high-resolution spectra for analytes as large as ∼6.4 kDa with little or no evidence of metastable decomposition. The absence of significant metastable decay observed for precursor ions selected for tandem experiments offered a further measure of the low energy content typical of ions generated by AP MALDI. This feature proved to be very beneficial in the characterization of chemically modified RNA samples, which become particularly prone to base losses upon alkylation. The high resolution offered by FTMS enabled the application of a data-reduction algorithm capable of rejecting any signal devoid of plausible isotopic distribution, thus facilitating the analysis of complex analyte mixtures produced by nuclease treatment of RNA substrates. Proper selection of nucleases and digestion conditions can ensure the production of hydrolytic fragments of manageable size, which could extend the range of applicability of this bottom-up strategy to the structural investigation of very large RNA and protein-RNA complexes.
Genetic damage in mammalian somatic cells exposed to radiofrequency radiation: a meta-analysis of data from 63 publications (1990-2005)

Abstract Vijayalaxmi and Prihoda, T. J. Genetic Damage in Mammalian Somatic Cells Exposed to Radiofrequency Radiation: A Meta-analysis of Data from 63 Publications (1990–2005). Radiat. Res. 169, 561–574 (2008). During the last several decades, numerous researchers have examined the potential of in vitro and/or in vivo exposure of radiofrequency (RF) radiation to damage the genetic material in mammalian somatic cells. A meta-analysis of reported data was conducted to obtain a quantitative estimate (with 95% confidence intervals) of genotoxicity in RF-radiation-exposed cells compared with sham-exposed/unexposed control cells. The extent of genotoxicity was assessed for various end points, including single- and double-strand breaks in the DNA, incidence of chromosomal aberrations, micronuclei and sister chromatid exchanges. Among the several variables in the experimental protocols used in individual investigations, the influence of three specific variables related to RF-radiation exposure characteristics was...
On bi-level conceptual schemas

The advent of Entity-Relationship (E-R) model has revolutionized the database design process. The overwhelming success of Entity-Relationship approach to database design partly lies in the simplicity and semantic clarity of the E-R model. However, two seemingly conflicting measurements of database design: logical-clarity and physical-efficiency, force database designers to choose either logically-clear design or physically-efficient design. As a result, the resulting design is either logically-clear or physically-efficient, but not both. This paper is to provide a remedy for this situation. In this paper, we first discuss the concept of logical-clarity and physical-efficiency of logical database design. Then the concept of bi-level conceptual schema is introduced. The bi-level conceptual schema concept allows us to create a logical database design that is both logically-clear and physically-efficient. Finally, a database management system prototype (DBMSB) that supports bi-level conceptual schema is described.
Verification of stress-intensity factors for various middle-crack tension test specimens

Abstract Recently, the stress-intensity factor equation used in the ASTM Standard Test Method for Measurement of Fatigue Crack Growth Rates (E-647) for the middle-crack tension M(T) specimens (friction-gripped or pin-loaded) has been questioned due to the influence of the specimen “height” specified in the standard. A boundary-element code has been used to calculate the stress-intensity factors for a wide range of crack-length-to-width ratios and various height-to-width ratios for M(T) specimens under remote uniform stress, remote uniform displacement, or pin-loaded holes. Comparisons are made with some of the well-known stress-intensity factor solutions and equations in the literature. Recommended specimen heights and stress-intensity factor equations have been made.
Massively parallel sequencing of enriched target amplicons for high-resolution genotyping of Salmonella serovars

With next generation sequencing (NGS) technology, it is now possible to carry out in-depth, large-scale sequencing projects, such as whole genome sequencing, in a fast and inexpensive manner. However, often it is more practical and convenient to sequence and analyze multiple, smaller regions of the bacterial genome to gain valuable information about an organism. One such application is genotyping of bacterial strains by multilocus sequence typing (MLST) that involves PCR and sequencing analysis of typically 7 housekeeping genes. Recently, we described a novel MLST method, called MLST-seq that combines a PCR-based target enrichment method and NGS technology to simultaneously analyze numerous target gene sequences, thereby improving the resolution and high-throughput capacity of current MLST approaches. However, the performance of the MLST-seq method was hampered from a substantial bias in target enrichment step. In this study, we used an improved target enrichment method using hairpin selectors to amplify 21 target genes simultaneously from each of 41 Salmonella strains. The resulting amplicons tagged with strain-specific barcodes were pooled and sequenced en masse by 454 pyrosequencing. Analysis of sequence data from 38 Salmonella strains using combinations of 3, 7 and 14 target genes resulted in 23, 32 and 37 distinct allelic profiles, respectively. These results demonstrated that MLST-seq with an increased number of target genes is an efficient way to improve discrimination among closely-related strains of Salmonella. With the rapidly increasing sequencing capacity of NGS technologies combined with further improvements in target capturing methods, MLST-seq could become a promising approach to perform high-resolution strain typing of a large collection of Salmonella, and likely other genera in a labor- and cost-efficient manner in the future.
The annealing of a quenched uranium-5 at % molybdenum alloy

Abstract Three reactions have been observed in the annealing of γ-quenched U-5 at % Mo: 1. (1) age-hardening in the supersaturated αb' phase; 2. (2) over-ageing with recrystallisation and discontinuous precipitation of non-equilibrium γ; and 3. (3) a second recrystallisation with re-precipitation to form a pearlitic structure. Mechanisms are proposed for all three reactions, and a possible explanation of the irradiation-swelling properties of the quenched structure is suggested.
Effect of carbon monoxide partial pressure on the high-temperature decomposition of Nicalon fibre

The high-temperature equilibrium partial pressures of the predominant gaseous species over Nicalon were determined thermochemically. It was calculated that the most prevalent gaseous species in equilibrium with Nicalon at 1300 °C is carbon monoxide. Subsequently, fibres of Nicalon (NLM 202) were heat treated at 1300 °C in various partial pressures of carbon monoxide gas and analysed via single filament strength testing, scanning electron microscopy, X-ray diffraction, and scanning Auger microscopy. The heat treatments in carbon monoxide had a significant effect on the strength retention and composition of the fibres (∼75% retained) compared to the treatments in argon where only 25% of the initial strength was retained. The Auger analysis revealed that the treatment in argon evolved carbon and oxygen from the fibre while in carbon monoxide atmospheres a carbon layer was deposited on the fibre surface. X-ray diffraction showed that grain growth had not occurred in any of the heat treatments. This study shows the important role of thermochemical reactions in the strength degradation of Nicalon, and its possible relationship to the formation of carbon surface/interface layers.
Acid precipitation and reproductive success of ambystoma salamanders

The two species of mole salamander that occur in the Ithaca, New York, region (Ambystoma maculatum and A. jeffersonianum) breed in temporary ponds that are formed by accumulation of melted snow and spring rains. Water in many of these pools during the breeding season is acid; pH values as low as 3.5 have been measured. In laboratory experiments A. maculatum tolerated pHs from 6 to 10 and had greatest hatching success at pH 7 to 9. Ambystoma jeffersonianum tolerated pH 4 to 8 and was most successful at pH 5 to 6. Mortality rose abruptly beyond the tolerance limits. The pH optimum shifted upward with increasing temperature for A. jeffersonianum and downward for A. maculatum. Judging from our laboratory studies, the acidity measured in breeding ponds should cause mortality in A. maculatum and permit normal development in A. jeffersonianum. In a 4 yr study of a large, acidic vernal pond, 938 adult A. maculatum produced 486 metamorphosed juveniles (0.52 juvenile/adult), while 686 adult A. jeffersonianum produced 2157 juveniles (3.14 juveniles/adult). Because the effects of acid precipitation on the salamanders' breeding ponds are cumulative from year to year, profound changes in the salamander populations can be anticipated.
SOCIOLINGUISTIC CHALLENGES TO MINORITY COLLEGIATE SUCCESS: ENTERING THE DISCOURSE COMMUNITY OF THE COLLEGE

A significant body of research has examined the reasons behind high minority collegiate attrition. All of this work has contributed to our understanding of the unique challenges minority and first generation college students face in the difficult transition to the often new culture that is the college experience. One area that has gone virtually ignored in the literature, however, is the relationship of language, discourse, and literacy to collegiate success. Because the university comprises its own “discourse community”—with its own “ways with words”—those wishing to help minority students in their transition to college should not ignore students’ levels of academic literacy. Rather, differences in language use contribute to many students’ feelings of alienation from the academic and social culture of the academy. Fortunately, results from this study support the thesis that students lacking academic literacy may be able to learn it—and have a better chance at academic success—through the efforts of college-preparatory programs, college-level student academic services programs, pre-collegiate “bridge” programs, and college mentoring programs.
Reflections on Gibbs: From Statistical Physics to the Amistad V3.0

This note is based upon a talk given at an APS meeting in celebration of the achievements of J. Willard Gibbs. J. Willard Gibbs, the younger, was the first American physical sciences theorist. He was one of the inventors of statistical physics. He introduced and developed the concepts of phase space, phase transitions, and thermodynamic surfaces in a remarkably correct and elegant manner. These three concepts form the basis of different areas of physics. The connection among these areas has been a subject of deep reflection from Gibbs’ time to our own. This talk therefore celebrated Gibbs by describing modern ideas about how different parts of physics fit together. I finished with a more personal note. Our own J. Willard Gibbs had all his many achievements concentrated in science. His father, also J. Willard Gibbs, also a Professor at Yale, had one great non-academic achievement that remains unmatched in our day. I describe it.
The BMP-7-Smad1/5/8 pathway promotes kidney repair after obstruction induced renal injury.

Purpose: Urinary tract obstruction causes hydroureteronephrosis and requires surgical intervention to prevent permanent renal injury. While many studies have focused on the development of renal injury, we examined the molecular mechanisms that promote renal recovery after correcting obstruction.Materials and Methods: A reversible murine model of ureteral obstruction was used to examine the bone morphogenic protein-7 and transforming growth factor-β signaling pathways during renal recovery after obstruction induced injury. Analysis was done using standard molecular techniques, including reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay, immunoblotting and co-immunoprecipitation.Results: After correcting obstruction the up-regulation of bone morphogenic protein-7 inhibited the transforming growth factor-β dependent profibrotic pathways that are central to renal injury pathogenesis. The inhibitory effects of bone morphogenic protein-7 were mediated in part by the activation o...
Transhepatic balloon dilation of anastomotic biliary strictures in liver transplant recipients: The significance of a patent hepatic artery

PURPOSE To determine the significance of hepatic artery steno-occlusive disease on the patency of anastomotic biliary strictures in liver transplant recipients after transhepatic balloon dilation. MATERIALS AND METHODS A retrospective review of records of all patients undergoing transhepatic balloon dilation for anastomotic biliary strictures after orthotopic liver transplantation was performed over an 8-year period. Patency of the anastomosis was based on subsequent cholangiography. The presence of hepatic artery steno-occlusive disease was determined by Doppler ultrasound and/or angiography. The anastomotic biliary stricture patency rates were calculated by the Kaplan-Meier method. RESULTS Thirty-eight patients who had undergone liver transplants underwent 53 balloon dilations for anastomotic biliary strictures (nine patients for arterial disease, 26 patients had patent arteries and three patients had arteries of indeterminate patency). Eight of the 53 strictures treated (15%) were refractory to balloon dilation: 10.5% of first comers and 27% of restenotic lesions. Two of the 53 strictures treated (4%) had significant complications: hemobilia requiring blood transfusion and ductal rupture. One-year cumulative primary patency rates for anastomotic biliary strictures for patients with arterial disease, patent hepatic arteries, and all-comers were: 0%, 45% ( P = .01), and 36%, respectively. One-year cumulative primary patency rates for choledocho-choledocal and choledocho-jejunal anstomoses in patients with patent arteries were 43% and 48%, respectively ( P = .10). CONCLUSIONS In the presence of hepatic artery disease there is a lower patency of anastomotic biliary strictures after balloon dilation. Imaging of the hepatic artery should be considered to stratify patients who will have a successful outcome.
Women's Difficult Times and the Rewriting of the Life Story:

Eighty-eight women in their early 50s described their most difficult time since college, the one that had most affected their subsequent lives. The age at occurrence and theme of the difficult times were related to each other, to gender role (whether or not the women were mothers), and to the self-system as assessed by similarity of each woman's California Q-sort description to Q-sort prototypes of ego-identity status. The themes of Independent Identity and its sequelae (Put-downs at work and Abandonment) were related to adequacy of ego identity and occurrence of difficult time between ages 36 and 46. California Psychological Inventory and other data from the women at ages 27, 43, and 52 helped to explain why “rewriting of the life story” tended to occur around age 40. Work by feminist literary critics is used for additional perspective.
ELECTRON MICROSCOPIC OBSERVATIONS ON THE POSTNATAL DIFFERENTIATION OF THE SEMINAL VESICLE EPITHELIUM OF THE LABORATORY MOUSE.

The cytological changes occurring in the epithelium of the mouse seminal vesicle between 5 and 49 days of postnatal life have been traced by electron microscopy. Initially the epithelium was composed of typical immature columnar cells. During the second week of life, the principal changes were: rapid cell proliferation, followed by increases in the amounts of organized ergastoplasm and Golgi material. During the third week, dense secretory material appeared in Golgi cisternae and then in the lumen of the gland. The parallelism between these changes and those found in maturing pancreatic acinar tissue has been assessed. Comment is made on the attachment of ribosomes to endoplasmic reticulum in the initiation of protein-secretory activity, and the importance of the subsequent proliferation of ergastoplasmic and Golgi membranes. The evidence for relating these cytological and secretory alterations in the seminal vesicle to a rising titer of androgen during the prepuberal period has been cited. Other observations included: (a) Evidence for a considerable amount of cellular sloughing and resorption during the first two postnatal weeks; (b) an association of mitochondria with developing desmosomes, and (c) the appearance of basal cells first during the second week of postnatal life, thus suggesting that they arise by dedifferentiation of columnar cells.
Emporiatrics: Diarrhea in Travelers

The litany of scatalogical euphemisms describing travelers’ diarrhea sounds more like a line-up for a horse race: turista, Aztec two-step, Ramses’ revenge, Casablanca crud, Bombay runs, Delhi belly and Tokyo trots. While the winner in this race is uncertain, the loser is the poor traveler whose most memorable image of an expensive, exotic vacation was a desperate search for bathrooms or confinement to a hotel room while others were enjoying the sights. Though self-limited and relatively mild compared to some diseases acquired abroad, the impact of travelers’ diarrhea on the traveler should not be underestimated.
Simplified electrode array for impedance cardiography.

Impedance cardiography has enjoyed widespread interest owing to the promise of noninvasive monitoring of cardiac function. In clinical practice, one factor limiting its use has been the need to use circumferential electrodes. These electrodes can be inconvenient to apply, may interfere with chest tubes or intravenous lines, and can cause additional apprehension in critically ill patients. The paper describes a more convenient electrode array. It uses four disposable electrocardiographic electrodes, two on the base of the neck and two on the lower left, anterolateral surface of the thorax. Simultaneous impedance derivative recordings were made with this ‘spot’ electrode array and with the conventional ‘band’ electrode array, at rest and after exercise on ten normal volunteers. On a given individual, the two signals had shapes which were remarkably similar and relative heights which correlated well, exhibiting correlation coefficients (r′) between 0·77 and 0·98. This new array should facilitate impedance cardiographic measurements in the clinical setting.
Synthesis of Oxaspiropentene

Epoxidation of either cis- or trans-1-methylene-2-bromo-3-(trimethylsilyl)cyclopropane by dimethyldioxirane followed by elimination of the epoxide over solid tetra-n-butylammonium fluoride using the vacuum gas−solid reaction procedure yields oxaspiropentene. The nuclear magnetic resonance spectrum of oxaspiropentene was recorded at −95 °C. Exact bond lengths were determined computationally.
pH-dependent solubility and assembly of microtubules in bovine brain extracts.

Alkaline pH favors the assembly of microtubules (MTs) in marine egg extracts [Suprenant and Marsh, 1987: J. Cell Sci. 184:167-180; Suprenant, 1989: Exp. Cell Res. 184:167-180; 1991: Cell Motil. Cytoskeleton 19:207-220] and mammalian brain extracts [Tiwari and Suprenant, 1993: Anal. Biochem. 215:96-103], even though the assembly of purified microtubule protein (MTP) from both of these sources is favored at slightly acidic pH. The present investigation examines whether alkaline pH has a direct or indirect effect on MT nucleation and growth in soluble brain extracts. Cell-free extracts were prepared from bovine cerebral cortex, and a nucleated assembly assay was used to demonstrate that MT assembly in brain extracts is favored at slightly acidic pH. The increase in MT mass found at alkaline pH is due to an increase in the solubility of tubulin not an increase in the extent of assembly On average, 47.7 ± 11.3% of the total tubulin is soluble at pH 7.2, while only 30.9 ± 8.9% of the tubulin is soluble at pH 6.8. A model is proposed that indicates how microtubule proteins from both mammalian brain and marine eggs may be associated with pH-dependent factors. © 1994 Wiley-Liss, Inc.
Interaction rate of polystyrene fiber optics with pseudocumene-based liquid scintillator

Abstract To quantify the risk of using wavelength shifting fiber immersed in pseudocumene-based liquid scintillator, we have measured the rate of reaction of the polystyrene core of this fiber with solutions of pseudocumene dissolved in mineral oil. The rate of reaction drops rapidly with concentration. For samples below 17% pseudocumene by volume, the amount of core that reacted in 18 months was less than our measurement limit of 6 μ m .
Multicolor Three-dimensional Whole-cell Imaging With Nanometer Scale Resolution

The ability to directly visualize nanoscopic cellular structures and their spatial relationship in all three dimensions will greatly enhance our understanding of molecular processes in cells. In this work, we have developed multicolor three-dimensional (3D) stochastic optical reconstruction microscopy (STORM) as a tool to probe molecular structures and their interactions on sub-diffraction length scales. STORM achieves sub-diffraction limit image resolution by using photoswitchable fluorescent probes to separate the spatially overlapping images of individual probes in time. Only a small subset of probes was activated at any given time, allowing us to resolve individual activated probes and determine their positions with high precision. A super-resolution image was then constructed by plotting the measured probe positions accumulated over time. With this we have generated 3D whole cell images, several micrometers thick, with a spatial resolution of 20 - 30 nm and 60 - 70 nm in the lateral and axial dimensions, respectively. Using this approach, we imaged the entire mitochondrial network in mammalian cells and studied the spatial relationship between mitochondria and the microtubule cytoskeleton. The 3D STORM images clearly resolved the hollow mitochondria outer membrane structures obscured in conventional fluorescence images. Distinct mitochondrial morphologies were observed, ranging from thin elongated tubes to globular compartments. Interestingly, while globular mitochondria are relatively dispersed in size, from 200 nm to 1500 nm, the tubular structures are more uniform in diameter, taking a narrow distribution around 200 nm. The images also displayed several distinct interaction modes between mitochondria and microtubules. Notably, elongated mitochondria were observed to “inchworm” along microtubules with discrete attachment sites, while such an interaction mode was completely unresolvable with conventional fluorescence. Super-resolution optical microscopy techniques such as STORM promise to significantly expand the understanding of biological structures and their interactions on a molecular level.
The hydrophobic effect drives the recognition of hydrocarbons by an anionic metal-ligand cluster.

We report the complexation of a series of n- and cycloalkanes by an anionic, metal−ligand cluster carrying a 12- charge. This host also encapsulates cyclodecane isomers such as adamantane, the dicy...
Inflammatory Mediators in Vascular Disease: Identifying Promising Targets for Intracranial Aneurysm Research

Inflammatory processes are implicated in many diseases of the vasculature and have been shown to play a key role in the formation of intracranial aneurysms (IAs). Although the specific mechanisms underlying these processes have been thoroughly investigated in related pathologies, such as atherosclerosis, there remains a paucity of information regarding the immunopathology of IA. Cells such as macrophages and lymphocytes and their effector molecules have been suggested to be players in IA, but their specific interactions and the role of other components of the inflammatory response have yet to be determined. Drawing parallels between the pathogenesis of IA and other vascular disorders could provide a roadmap for developing a mechanistic understanding of the immunopathology of IA and uncovering useful targets for therapeutic intervention. Future research should address the presence and function of leukocyte subsets, mechanisms of leukocyte recruitment and activation, and the role of damage-associated molecular patterns in IA.
In Vitro Studies of the Human Mammary Gland: Effect of Hormones on Proliferation in Primary Cell Cultures

Epithelial cells from the human mammary gland were propagated up to 40 days in vitro as primary cell cultures. Large and medium-sized ducts, dissected from 4 different glands, served as a specific source of the epithelial cells. Ducts were opened, cut in small pieces, and were treated with trypsin-EDTA. The loosened epithelial cells were obtained in suspension and inoculated into Petri dishes where they attached, maintained their epithelial shape and grew as cohesive sheets of cells. The cultured cells had certain ultrastructural features in common with control uncultured cells of the ducts. In cultures from 2 mammary glands, addition of insulin or prolactin to serum-containing culture fluid did not result in any increase in the mitotic index or number of cells synthesizing DNA. Hydrocortisone, on the other hand, suppressed mitosis and DNA synthesis. This system should make possible additional studies of human mammary gland biology and pathology.
Capturing the essential spatial variability in distributed hydrological modelling: Hydraulic roughness

The spatial variability of each parameter affecting storm runoff must be accounted for in distributed modelling. The objective of the work reported here is to assess the effects of using distributed versus lumped hydraulic roughness coefficients in the modelling of direct surface runoff. A spatially variable data set composed of Manning roughness coefficients is used to model direct surface runoff. To assess the information content (as measured by entropy) of spatially variable data and its significance in distributed modelling, various degrees of smoothing are applied. The error resulting from smoothing the hydraulic roughness coefficients is determined by modelling overland flow using a finite element solution. The Manning roughness coefficients were taken from field measurements of the Manning roughness coefficient at 0.6 m on a 14 m hillslope. These values were then used in a numerical simulation of outflow hydrographs to investigate the dependence of error on spatial variability. Our study focuses on the characteristics of spatial data used in distributed hydrological modelling. The field sites have fractal dimensions of ≈ 1.4, which is close to a Brownian variation. The sampling interval that captures the essential spatial variability of the Manning roughness coefficient does not seem to matter due to its Brownian variation in the field sites. Hence due to the nearly uniform random distribution, measurements at 0.6 m intervals are not necessary and larger intervals would yield results that are just as acceptable provided the mean value together with a uniformly random distribution is maintained for any size of finite element or sampling resolution. Because detailed measurements of hydraulic roughness are not practically available for deterministic catchment modelling, it is important to know that larger sampling resolutions may be used than 0.6 m.
The 2007–2010 U.S. financial crisis: Its origins, progressions, and solutions

Abstract The 2007–2010 financial crisis was originated from excessive liquidity afforded by low interest rates and active securitization of mortgages and their derivatives. The excess liquidity flowed into the subprime mortgage market until interest rates increased in 2005 and an economic recession followed soon thereafter. The start of a large-scale mortgage market meltdown in 2007 coupled with the 2007–2009 Great Recession caused a severe liquidity freeze. Many financial institutions had to fail and their failures created more uncertainty about the prospect for mortgage market and economic recovery. In an attempt to provide liquidity to the credit market and thus stabilize the economy, various policies were implemented. After revisiting the origins and progressions of the crisis, this paper examines closely three major controversial policy actions: the bankruptcy of Lehman Brothers; the policy reversal from debt purchase to capital purchase under TARP; and the bailout of AIG. After a detailed review of these cases, the paper highlights a few noteworthy solutions to prevent future crises as embedded in the Dodd–Frank Act and then, introduces a few possible solutions for quicker economic recovery that the Dodd–Frank Act overlooked.
Positive-strand RNA viruses infecting the red imported fire ant, Solenopsis invicta.

The imported fire ants, Solenopsis invicta and S. richteri were introduced into the USA between 1918 and 1945. Since that time, they have expanded their USA range to include some 138 million hectares. Their introduction has had significant economic consequences with costs associated with damage and control efforts estimated at 6 billion dollars annually in the USA. The general consensus of entomologists and myrmecologists is that permanent, sustainable control of these ants in the USA will likely depend on self-sustaining biological control agents. A metagenomics approach successfully resulted in discovery of three viruses infecting S. invicta. Solenopsis invicta virus 1 (SINV-1), SINV-2, and SINV-3 are all positive, single-stranded RNA viruses and represent the first viral discoveries in any ant species. Molecular characterization, host relationships, and potential development and use of SINV-1, SINV-2, and SINV-3 as biopesticides are discussed.
Noise of space-charge-limited current in solids is thermal

The white noise level of space-charge-limited current (SCLC) of holes in a silicon device measured at five temperatures ranging from 113 to 300 K is shown to be proportional to the absolute temperature. This proves experimentally the thermal origin of noise for SCLC in solids.
Variational approach to the solution of linear multiparameter eigenvalue problems

We associate a multiparameter spectral problem in a real Euclidean space with a variational problem of finding a minimum of a certain functional. We establish the equivalence of the spectralproblem and the variational problem. On the basis of the gradient procedure, we propose a numerical algorithm for the determination of its eigenvalues and eigenvectors. The local convergence of the algorithm is proved.
Neuroimaging of brain injury in neonates treated with extracorporeal membrane oxygenation: Lessons learned from serial examinations

Abstract The head ultrasound (US) is used extensively at most extracorporeal membrane oxygenation (ECMO) centers to screen for intracranial pathology in the ECMO candidate. Daily head US examinations are obtained in patients on ECMO to detect the emergence of intracranial hemorrhage (ICH). The authors asked whether these serial studies could be correlated with more definitive diagnostic studies, such as computed tomography (CT) and magnetic resonance imaging (MRI) scans, autopsy data, or the long-term neurodevelopmental status, to discern the predictive value of these daily examinations. Seventy-four consecutively treated neonates with reversible respiratory failure refractory to conventional support met institutional criteria for placement on ECMO. In addition to a pre-ECMO US, daily real-time portable head US images were evaluated for changes in echotexture, ventricular configuration, and extraaxial fluid. Follow-up CT and MRI scans were evaluated for the presence of hemorrhagic or ischemic lesions. Autopsy data were obtained from nonsurvivors. Survivors were examined by a neurodevelopmental specialist at regular intervals and classified as normal or delayed for chronological age. In this series of 74 patients, CT MRI scanning and autopsy data demonstrated structural injury in 19 patients; there were 16 ischemic infarctions and three hemorrhages. The incidence of hemorrhage in this series was considerably lower than that previously reported. Ten of the 19 patients had serial head US findings demonstrating a progression from focal increases in echotexture to diffuse effacement of cerebral architecture. In the remaining nine, serial head US examinations did not show injury. An additional 10 children had a clear delay in neurological development despite no evidence of anatomic injury on serial head US examinations or CT MRI scanning. The mortality was 42% for neonates who had either an abnormal head US result or an abnormal result on the follow-up neuroimaging study. In the 43 patients without evidence of such injury, the mortality was 16%.
Axonal growth and guidance

Abstract The motile behavior of growing nerve tips expands the front margins of the neurite and generates mechanical forces that pull neurite components forwards. These activities promote the assembly and organization of cell components into the growing nerve fiber. Extrinsic factors, adhesion, chemical gradients, and possibly electric currents, influence nerve fiber growth through local effects on the basic motile activities in the nerve tip. Results from studies in embryos also suggest that axons are directed by extrinsic effects on the motile behavior of growth cones.
Density gradient relaxation: A method for preparative buoyant density separations of DNA

Abstract A multi-speed centrifugation procedure, called the “density gradient relaxation method”, has been applied to buoyant density separations of milligram quantities of a DNA mixture. With relaxation, larger quantities of DNA can be separated in shorter times than with conventional one-speed centrifugations.
The Development of Isocitric Lyase Activity in Germinating Cotton Seed

In cotyledons of germinating cotton (Gossypium hirsutum L. var. Stoneville 213) seedlings, in the dark, isocitric lyase (EC 4.1.3.1) activity peaks after 2 days and thereafter slowly declines to a negligible value after 8 days. The maximum activity of this enzyme in cotyledons of 2-day-old seedlings was 16.2 mumoles of glyoxylate formed/15 min.10 cotyledon pairs. Actinomycin D at a concentration of 10 mug/ml, if added to the imbibing solution, completely prevents the development of isocitric lyase activity in these germinating seed. In cotyledons of germinating cotton seedlings, in the light, isocitric lyase activity peaks after 2 to 3 days and sharply declines to a negligible value after 4 days. The maximum activity of this enzyme in cotyledons of 2- to 3-day-old seedlings was 13.2 mumoles of glyoxylate formed/15 min.10 cotyledon pairs. Actinomycin D at a concentration of 10 mug/ml, if added to the imbibing solution, severely inhibits the development of enzyme activity.In germinating seed, in the light, the synthesis of chlorophyll and glyceraldehyde-3-P dehydrogenase is also limited by the addition of low concentrations of actinomycin D. The new synthesis of fructose-1, 6-diP aldolase, which is detectable after 1 to 2 days of germination, is inhibited by 10 mug/ml of actinomycin D. We, therefore, conclude that the synthetic events leading to the development of chlorophyll, some glyoxysomal and chloroplast enzymes in germinating cotton seedlings depend on newly transcribed mRNA.
Probe Reversal and Pressure Based Bias Error Correction Procedures Applied to Intensity Measurements in Planar Standing Waves

An analytical application of probe reversal and pressure correction strategies to minimize channel phase errors in P-P intensity measurements within discrete frequency standing waves is made. Two potential error sources, error of position upon reversal and error of pressure correction, are examined and found negligible at low frequencies but likely to be problematic at high frequencies. It is predicted that pressure correction or probe reversal can lead to superior performance when compared with measures without correction at modest and higher standing wave ratios in true intensity assessment; the frequency range for a given probe spacing is also extended. The correction procedures are then applied to low frequency measurements (63 Hz and 125 Hz) for a range of standing wave ratios. It is found that correction procedures generally lead to better results than uncorrected measures, but beyond a standing wave ratio of about 30 dB at 63 Hz additional error source arises which renders inaccurate the result of correction procedures, particularly for smaller probe spacing measures
Nature of the charge carriers in electron-doped copper oxide superconductors

The charge carriers in all of the well-known layered copper oxide high-temperature superconductors1– are holes located in the CuO2planes, the common structural element of these systems. Recently, Tokura et al.5 have reported that doping of Ln2CuO4, where Ln represents Pr, Nd or Sm, with formally tetravalent Ce can produce a high-temperature superconductor with electron carriers. To determine the character of the carrier states in Nd2–xCexCuO4, we have performed X-ray absorption measurements at the Cu K and Ce L3 edges for several different Ce concentrations. We find clear evidence that the electrons introduced by doping fill 3d holes on the Cu atoms, thus converting some Cu2+ ions to Cu+. Hence the nature of the states nearest to the Fermi energy (that is, those responsible for conduction) is qualitatively different from that in the hole-doped superconductors, in which the holes move in a band formed predominantly from O 2p states8–10. As a result, the details of the electron-pairing mechanism could be very different in the two systems11.
Suppression of ionization in one- and two-dimensional-model calculations

We study numerically ionization from a model atom induced by a strong high-frequency field. Both one- and two-dimensional models are considered. We discuss the physics of ionization suppression in strong fields and point out the differences between one- and higher-dimensional models. We also discuss the applicability of classical modeling.
Role of dying endothelial cells in transendothelial macromolecular transport.

There are focal areas in the aorta with an enhanced endothelial permeability to macromolecules, as indicated by the focal uptake of the protein-binding azo dye Evans blue in vivo. These areas exhibit high rates of endothelial cell turnover and a number of structural characteristics in en face endothelial morphology. To determine the relationship of endothelial cell death to macromolecular leakage at the level of individual endothelial cells, thoracic aortas of 12 adult male Sprague-Dawley rats were studied at 3 to 5 minutes after intravenous administration of Evans blue-albumin (EBA). Leakage of EBA around individual endothelial cells in en face preparations of the aorta was visualized by fluorescence microscopy. Dying or dead endothelial cells were identified by indirect immunoglobulin G (IgG) immunocytochemistry. Although endothelial cell death is uncommon in normal aortic endothedium (i.e., an average frequency of 0.48%), a high percentage (63%) of IgG-containing dying or dead endothelial cells was found to be associated with EBA leakage. These dying or dead endothelial cells were responsible for 37% of total EBA leaky foci. The results suggest that, in addition to mitotic endothelial cells, the dying or dead endothelial cells also make significant contributions to the local enhancement in aortic endothelial permeability. The present findings lend further support to the "cell turnover-leaky junction" hypothesis for the localization of atherosclerosis.
Mechanics-based model for non-affine swelling in perfluorosulfonic acid (PFSA) membranes

Abstract A mechanics-based model is developed to predict the swelling pressure in perfluorosulfonic acid (PFSA) ionomer membranes during water uptake. The PFSA membrane is represented as a two-phase system, where the water-filled hydrophilic domains are dispersed throughout the hydrophobic polymer matrix. Two representative volume elements (RVEs) are used to represent the nanostructure: (i) a spherical RVE with a spherical hydrophilic domain at the center, and (ii) a cylindrical RVE with a cylindrical hydrophilic domain. The model starts with the non-affine swelling behavior of the membrane and interprets this as a structural reorganization of the RVEs to characterize the microscopic deformation. Swelling pressure is then determined as a function of water volume fraction and temperature for both RVEs. Using the resulting relationship between the swelling pressure and water volume fraction, theoretical sorption isotherms are generated. The results suggest that with increasing temperature, the constraining pressure due to the deformation of the polymer region decreases and therefore, water uptake in a vapor-equilibrated PFSA membrane increases. This relationship is consistent with previously-reported experimental data. The model can also account for the effect of residual water in the membrane – which is associated with the membrane's thermal history – on the sorption behavior. The proposed continuum mechanics model can serve as a tool for deeper understanding of the sorption behavior of PFSA by bridging the gap between the molecular level descriptions and the experimental observations of macroscopic swelling.
The effect of the jet-stream on the intensity of laser beams propagating along slanted paths in the upper layers of the turbulent atmosphere

Calculations of the second-order statistical characteristics of a polarized, lowest-order Gaussian beam which propagates through a jet-stream layer, in the upper troposphere and lower stratosphere (UTLS) environment, are carried out. Comparison of the results based on the refractive-index structure parameter as predicted by a Hufnagel–Valley model and based on data taken at a recent campaign of measurements and high-resolution numerical simulations shows that the jet-stream can significantly affect the intensity distribution and spreading of the beam, especially at high zenith angles.
Interaction of an inserted monolayer well with the conduction band of a Si/Si1-xGex superlattice.

La methode de la matrice de transfert de Sterke et Hall est etendue a l'Hamiltonien general du super-reseau Si/Si 1−x Ge x . La methode, appliquee au super-reseau n×n montre que l'on peut gagner en flexibilite en changeant la bande interdite de la minibande et en augmentant la largeur de la minibande lorsqu'un puits simple d'une monocouche est insere dans la barriere. Une structure de bandes a transition quasidirecte peut egalement resulter de l'insertion d'une barriere dans le puits multicouches, mais elle est sensible a la variation de l'epaisseur
A new method for resolving combinatorial ambiguities at hadron colliders

We present a new method for resolving combinatorial ambiguities that arise in multi-particle decay chains at hadron colliders where the assignment of visible particles to the different decay chains has ambiguities. Our method, based on selection cuts favoring high transverse momentum and low invariant mass pairings, is shown to be significantly superior to the more traditional hemisphere method for a large class of decay chains, producing an increase in signal retention of up to a factor of 2. This new method can thus greatly reduce the combinatorial ambiguities of decay chain assignments.
Antigens present on human myeloid leukemia cell lines.

Abstract Two human acute myelogenous leukemia cell lines have recently been established: KG-1 and HL-60. Both lines retain the morphology and cytochemistry of myeloid cells, are not infected with EB virus, and respond to colony-stimulating activity (CSA) with increased colony formation in soft-gel culture. The K 562 cell line is composed of undifferentiated blast cells which are rich in glycophorin and may be induced to produce human fetal and embryonic hemoglobin. We used a variety of antisera to characterize the antigen composition of the leukemic colony-forming cells (CFC) and the general population of leukemic cells. Cells were incubated with antisera and complement, washed, plated in agar, and the colonies counted after 12 days' incubation. Culture data were correlated with the results obtained using direct and indirect immunofluorescence and dye exclusion microcytotoxicity. The majority of KG-1 cells, including CFC, expressed the ‘Ia-like’ antigen. The HL-60 and K562 cells did not express the Ia antigen, although indirect evidence using cytogenetic and isoenzyme studies suggests that the HL-60 gene locus for the antigen was probably intact. We found that the leukemia CFC had the HLA-A and -B antigens as did the general leukemia cell population. The leukemia CFC did not express a T-lymphocyte antigen, certain erythrocyte antigens, nor antigens associated with acute lymphocytic leukemia. HL-60 cells underwent morphological and functional maturation in the presence of DMSO, but no change in surface antigenic composition was noted. All antigens expressed on the leukemia CFC were also present on the general cell population.