cssi/SciSciGPT-SciSciNet huggingface dataset:
Autoignition study of iso-cetane/tetralin blends at low temperature

Abstract iso-Cetane and tetralin are the two fuel components commonly considered in literature diesel surrogates, and are hydrocarbon classes representative of iso-alkanes and naphthoaromatics, respectively. Since both surrogate components are involved in the key reactions controlling the autoignition reactivity of diesel surrogates, autoignition studies of iso-cetane, tetralin, and their blending behavior at low temperatures can be helpful in developing/refining chemical kinetic models of diesel surrogates, in order to better predict diesel ignition response under low temperature combustion conditions. In this investigation, autoignition experiments of iso-cetane, tetralin, and their binary mixtures at varying blending ratios have been conducted in a rapid compression machine (RCM) in the temperature/pressure range of 630–930 K and 10–20 bar. For the neat fuel components, the newly-acquired RCM data have been compared with the literature experimental results at some overlapping conditions. In addition, a chemical kinetic model describing the oxidation of iso-cetane and tetralin compiled/updated from the diesel surrogate model developed by Lawrence Livermore National Laboratory is used to simulate the experimental datasets. It is shown that this model exhibits good agreement with the experimental results of tetralin and also predicts the total ignition delay times of iso-cetane at lower temperatures reasonably well. However, the current model fails to fully capture the increase of total ignition delay time with increasing amount of tetralin in the binary blends observed in the present RCM experiments. Therefore, chemical kinetic analyses of the current model are conducted to help identify possible reasons leading to the discrepancies between simulations and experiments. Furthermore, the chemical kinetic interactions between iso-cetane and tetralin are explored by including additional cross-reactions among iso-cetane, tetralin, and their fuel fragments in the current model to assess their effects on model predictions. Based on the chemical kinetic analysis results, future direction for model refinements is discussed.
Magnetic resonance imaging of pediatric liver tumors

Liver tumors in children can be benign or malignant. Although several clinical factors are important in the evaluation of these lesions, MRI is particularly important for lesion characterization and tumor staging. In children, use of a hepatobiliary contrast agent is recommended to evaluate a known or suspected liver lesion. In this review, we discuss the most common benign and malignant pediatric liver tumors, including vascular tumors, mesenchymal hamartoma, focal nodular hyperplasia, hepatocellular adenoma, hepatoblastoma, hepatocellular carcinoma, fibrolamellar hepatocellular carcinoma, undifferentiated embryonal sarcoma and metastases, with emphasis on relevant clinical information and imaging appearance at MRI using hepatobiliary agents.
9(b) or Not 9(b)? That Is the Question: How To Plead Negligent Misrepresentation in the Post- Twombly Era

Perhaps nothing is more important to a litigant bringing an action in federal court than knowing the relevant pleading standard for his or her underlying claims. Ever since the inception of the Federal Rules of Civil Procedure, one of two pleading standards have applied to common law claims: the Rule 8(a)(2) standard, requiring a short and plain statement demonstrating entitlement to relief, or the Rule 9(b) standard, demanding that allegations of fraud or mistake be pled with particularity. At the intersection of these two pleading standards is the common law claim of negligent misrepresentation. Courts across the country have long disagreed over which standard should apply to negligent misrepresentation claims, with divisions present across and within circuits and districts. In 2007, the U.S. Supreme Court further complicated this issue in the seminal opinion Bell Atlantic Corp. v. Twombly, which effectively imposed a heightened “plausibility” requirement for claims governed by Rule 8(a)(2). This change has since led some lower courts, but not all, to reconsider which pleading standard to apply to claims of negligent misrepresentation. This Note: (1) explores the pleading standards and their evolution with respect to negligent misrepresentation claims; (2) describes the circuit split and intracircuit fractures that have emerged from the different standards; (3) analyzes the significant procedural and substantive problems the competing standards have created, especially in light of Twombly; and (4) offers a possible resolution comporting with the Twombly holding to standardize the pleading of negligent misrepresentation claims across the nation’s federal courts.
Towards manipulation planning with temporal logic specifications

Manipulation planning from high-level task specifications, even though highly desirable, is a challenging problem. The large dimensionality of manipulators and complexity of task specifications make the problem computationally intractable. This work introduces a manipulation planning framework with linear temporal logic (LTL) specifications. The use of LTL as the specification language allows the expression of rich and complex manipulation tasks. The framework deals with the state-explosion problem through a novel abstraction technique. Given a robotic system, a workspace consisting of obstacles, manipulable objects, and locations of interest, and a co-safe LTL specification over the objects and locations, the framework computes a motion plan to achieve the task through a synergistic multi-layered planning architecture. The power of the framework is demonstrated through case studies, in which the planner efficiently computes plans for complex tasks. The case studies also illustrate the ability of the framework in intelligently moving away objects that block desired executions without requiring backtracking.
Poverty and Crime: Evidence from Rainfall and Trade Shocks in India *

Does poverty lead to crime? We shed light on this question using two independent and exogenous shocks to household income in rural India: the dramatic reduction in import tariffs in the early 1990s and rainfall variations. We find that trade shocks, previously shown to raise relative poverty, also increased the incidence of violent crimes and property crimes. The relationship between trade shocks and crime is similar to the observed relationship between rainfall shocks and crime. Our results thus identify a causal effect of poverty on crime. They also lend credence to a large literature on the effects of weather shocks on crime and conflict, which has usually assumed that the income channel is the most relevant one.
Letter to the Editor: 1H, 15N and 13C assignments of the N-terminal domain of Yersinia outer protein H in its apo form and in complex with a phosphotyrosine peptide

Pathogenic species of the genus Yersinia cause the plague and a range of other gastrointestinal syndromes (Cornelis et al., 1997). The 51 kDa Yersinia outer membrane protein H (YopH) is injected into host cells by a type III secretion system, and defeats their nonspecific immune response by selective dephosphorylation of essential signaling proteins (Black et al., 2000). YopH contains a tyrosine phosphatase domain (residues 190–468) while the signals for secretion and translocation are contained in the first 71 residues. The host cell focal adhesion proteins p130 and SKAP-HOM are cellular substrates of YopH (Black et al., 2000). These proteins have multiple tyrosine phosphorylation sites in their substrate binding regions that conform to the YopH recognition motif DE(pY)XXP. Moreover, it was demonstrated that residues 1–129 of YopH (YopH-NT) bind to p130 in a phosphotyrosine-dependent manner (Black et al., 1998). Besides secretion, the N-terminal region has therefore the additional function of targetting the catalytic domain to substrates in the infected cell. The Yop virulon comprised of YopH and about 40 other proteins is a well-characterized archetype of type III secretion systems present in many pathogenic Gram-negative bacteria. Study of the structure and function of YopH-NT is thus not only of interest for the understanding of the pathogenic action of YopH itself, but also for insight into the mechanism of infection by a large class of organisms. Elucidation of YopH structure and function might thus contribute
CO2 and Climate Change

On time scales of tens of millions of years, climate is known to undergo massive changes. Previous evidence has suggested a link between natural atmospheric COvariability and these long-term climatic oscillations, but some recent studies have found discrepancies. In their Perspective, Crowley and Berner assess the evidence. They conclude that the COmodel is valid for high-latitude glaciations but that for low latitudes, altered tectonic settings and problems with interpreting climate indicators complicate the picture.
Nucleosome Linking Number Change Controlled by Acetylation of Histones H3 and H4

High levels of acetylation of lysines in the amino-terminal domains of all four core histones, H2A, H2B, H3, and H4, have been shown to reduce the linking number change per nucleosome core particle in reconstituted minichromosomes (Norton, V. G., Imai, B. S., Yau, P., and Bradbury, E. M. (1989) Cell 57, 449-457). Because there is evidence to suggest that the acetylations of H3 and H4 have functions that are distinct from those of H2A and H2B, we have determined the nucleosome core particle linking number change in minichromosomes containing fully acetylated H3 and H4 and very low levels of acetylation in H2A and H2B. This linking number change was -0.81 +/- 0.05, in close agreement with the linking number change for hyperacetylated nucleosome core particles which contain high levels of acetylation in all four core histones (approximately 70% of full acetylation in H3 and H4). Therefore, high levels of acetylation of H3 and H4 alone are responsible for the reduction in the linking number change per nucleosome core particle.
ES Cells to the Rescue

Unlocking the therapeutic potential of embryonic stem (ES) cells has remained a tantalizing but elusive goal. In their Perspective, Chien, Moretti and Laugwitz discuss new work ( Fraidenraich et al.) showing that ES cells can rescue otherwise lethal cardiac defects in mouse embryos even when injected into the peritoneum of the mother prior to conception. The rescue effect is not due to differentiation of the ES cells into cardiac cells per se, but rather to their secretion of factors that act locally or at a distance via the maternal circulation to trigger proliferation of cardiac muscle cells in the mutant mouse embryos.
Parallel electric fields in a simulation of magnetotail reconnection and plasmoid evolution

Properties of the electric field component parallel to the magnetic field (E sub parallel) in a three-dimensional MHD simulation of plasmoid formation and evolution in the magnetotail in the presence of a net dawn-dusk magnetic field component were observed. Particularly emphasized was the spatial location of E(sub parallel), the concept of a diffusion zone and the role of E(sub parallel) in accelerating electrons. A localization of the region of enhanced E(sub parallel) in all space directions with a strong concentration in the z direction was found. This region was identified as the diffusion zone, which plays a crucial role in reconnection theory through the local break-down of magnetic flux conservation. The presence of B(sub y) implies a north-south asymmetry of the injection of accelerated particles into the near-earth region, if the net B(sub y) field is strong enough to force particles to follow field lines through the diffusion region. It is estimated that for a typical net B(sub y) field this should affect the injection of electrons into the near-earth dawn region, so that precipitation into the Northern (Southern) Hemisphere should dominate for duskward (dawnward) net B(sub y). In addition, a spatial clottiness of the expected injection of adiabatic particles which could be related to the appearance bright spots in auroras was observed.
ON RELIABLE FINITE ELEMENT METHODS FOR EXTREME LOADING CONDITIONS

In this paper we focus on the analysis of solids and structures when these are subjected to extreme conditions of loading resulting in large deformations and possibly failure. The analysis should be conducted with finite element methods that are as reliable as possible and effective. The requirement of reliability is important in any finite element analysis but is particularly important in simulations involving extreme loadings since physical test data are frequently not available, or only available for some similar conditions. To then reach a high level of confidence in the computed solutions requires that reliable finite element procedures be used. While in this paper a large field of analysis is covered, the presentation is narrow because it only focuses on our research results, mostly published in the last decade (since 1995), and only on some of our contributions. Hence, this paper is not written to fully survey the field.
Isolation and Characterization of Human Milk Lysozyme

A modified technique for the isolation of human milk lysozyme (HML)4 is described. The method yielded a protein with a specific activity of 3.5 as compared to egg-white lysozyme's (EWL) value of 1.0. The isoelectric point was 10.5–11.0, slightly higher than that of EWL. The sedimentation velocity molecular weight was found to be 16,000 with a sc=o20.w of 2.19, D20.w of 11.92, and v of 0.721 ml/g. The molecular weight by short-column sedimentation equilibrium was 15,000 ± 600. The amino acid analysis gave 123 ± 2 residues per mole, with a minimum molecular weight of 14,000. The enzyme also showed high thermal stability and a single pH optimum at 6.35.
Base-to-apex gradient of cell proliferation in the chick cochlea following kanamycin-induced hair cell loss.

Abstract In order to elucidate the mechanisms that drive cell proliferation in the avian cochlea, we investigated the spatio-temporal relationship between hair cell degeneration and cell proliferation after aminoglycoside otoxicity. Neonatal chicks were given a daily intramuscular injection of kanamycin (KM) at 400 mg/kg per day for 10 consecutive days. At various times during or after KM administration, proliferating cells were labeled over a period of 2 days with bromodeoxyuridine (BrdU) and visualized with peroxidase immunohistochemistry. Changes in the location of the hair cell lesion during the KM treatment were monitored by phalloidin immunofluroscence or scanning electron microscopy. Hair cell loss began at the base of the cochlea 6 days after the start of KM injections, whereas cell proliferation was first observed in the basal region between days 6 and 8 of the KM treatment. This indicates that the latency between cell loss and cell proliferation is less than 48 h. The region of cell proliferation shifted from the base toward the apex of the cochlea over a period of 6–8 days, but cell proliferation in a specific region of the cochlea only occurred for 2–4 days. The latency as well as the total duration of cell proliferation after KM ototoxicity was virtually equivalent to that observed after acoustic trauma (Hashino and Salvi, 1993), suggesting that similar cellular events are involved in triggering cell proliferation after mechanical destruction and metabolic destruction of avian hair cells. The spatio-temporal gradient of cell proliferation followed the pattern of hair cell loss, suggesting that some aspect of hair cell degeneration provides trigger signals for cell proliferation.
AGENDA FOR DEFENSE AND PEACE ECONOMICS

This brief introduction celebrates the 20th Anniversary of the Journal, Defence and Peace Economics. Suggesting elements of an agenda for the future of this branch of economics, I raise several topics that are new and that seem to indicate that the field will expand and shift focus substantially in future years.
The major deformational patterns characteristic of the Earth's Crust and their mechanics-of-origin

The sum of available geophysical and geological information has at last advanced to a point where it is possible to state with confidence that certain major deformational patterns are characteristic of the Earth's crust, and that the mechanics-of-origin of these patterns can be confidently postulated on the basis of ordinary physical and engineering experience. In the past incomplete (and partly incorrect) evidence regarding geotectonic problems has led to much uncertainty and disagreement—but with the accumulation of volcanological-seismological, geodetic-and-gravitational, and topographic-and-geologic evidence, the total evidence has fallen into focus and the general terms of the picture stand clearly revealed, showing that the Earth's crust can move (and is moving) laterally with respect to the centrosphere, that these movements are differential and in various directions, that surpluses of crustal area (as in an ice-floe or icepack) are recurrently eliminated by crumpling and overthrusting along interconnecting linear zones of weakness and fracture, and that the deformational patterns observed are primarily due to compression (with incidental tension and twisting). This compression operates in a relatively strong, brittle crust, underlain by a “zone of isostatic adjustment” characterized (either continuously or recurrently) by much greater mobility.
Improving GPU Performance Prediction with Data Transfer Modeling

Accelerators such as graphics processors (GPUs) have become increasingly popular for high performance scientific computing. Often, much effort is invested in creating and optimizing GPU code without any guaranteed performance benefit. To reduce this risk, performance models can be used to project a kernel's GPU performance potential before it is ported. However, raw GPU execution time is not the only consideration. The overhead of transferring data between the CPU and the GPU is also an important factor; for some applications, this overhead may even erase the performance benefits of GPU acceleration. To address this challenge, we propose a GPU performance modeling framework that predicts both kernel execution time and data transfer time. Our extensions to an existing GPU performance model include a data usage analyzer for a sequence of GPU kernels, to determine the amount of data that needs to be transferred, and a performance model of the PCIe bus, to determine how long the data transfer will take. We have tested our framework using a set of applications running on a production machine at Argonne National Laboratory. On average, our model predicts the data transfer overhead with an error of only 8%, and the inclusion of data transfer time reduces the error in the predicted GPU speedup from 255% to 9%.
Pretreatment predictors of dropout from cognitive behavioral therapy for PTSD in Iraq and Afghanistan war veterans.

Cognitive– behavioral therapies (CBTs) can be effective treatments for posttraumatic stress disorder (PTSD) but their effectiveness is limited by high rates of premature dropout. Few studies have compared pretreatment characteristics of treatment completers and dropouts, and only one has examined these factors in Operations Iraqi Freedom and Enduring Freedom (OIF/OEF) Veterans. This study analyzed archival clinical data from 117 OEF/OIF Veterans evaluated and treated through a Veterans Affairs PTSD clinic. High numbers dropped out of treatment (68%). Treatment dropouts (n 79) and completers (n 38) differed significantly on Minnesota Multiphasic Personality Inventory-2 (MMPI-2) scales, PTSD symptom severity, and age. Regression analyses identified one MMPI-2 scale, TRT (negative treatment indicators), and age as unique but modest predictors of dropout.
Predicting malaria interactome classifications from time-course transcriptomic data along the intraerythrocytic developmental cycle

Objective: Even though a vaccine for malaria infections has been under intense study for many years, it has resisted several different lines of attack attempted by biologists. More than half of Plasmodium proteins still remain uncharacterized and therefore cannot be used in clinical trials. The task is further complicated by the metamorphic life-cycle of the parasite, which allows for rapid evolutionary changes and diversity among related strains, thus making precise targeting of the appropriate proteins for vaccination a technical challenge. We propose an automated method for predicting functions for the malaria parasite, which capitalizes on the importance of the intraerythrocytic developmental cycle data and expression changes during its five phases, as determined computationally by our segmentation algorithm. Materials and methods: Our method combines temporal gene expression profiles with protein-protein interaction data, sequence similarity scores, and metabolic pathway information to produce a set of predicted protein functions that can be used as targets for vaccine development. We use a Bayesian approach, which assigns a probability of having (or not having) a particular function to each protein, given the various sources of evidence. In our method, each data source is represented by either a functional linkage graph or a categorical feature vector. Results and conclusions: The methods are tested on Plasmodium falciparum, the species responsible for the deadliest malaria infections. The algorithm was able to assign meaningful functions to 628 out of 1439 previously unannotated proteins, which are first-choice candidates for experimental vaccine research. We conclude that analyzing time-course gene expression profiles in separate phases leads to much higher prediction accuracy when compared with Pearson correlation coefficients computed across the time course as a whole. Additionally, we demonstrate that temporal expression profiles alone are able to improve the predictive power of the integrated data.
Further biochemical and kinetic characterization of human eukaryotic initiation factor 4H.

A cDNA encoding human eukaryotic initiation factor (eIF) 4H was subcloned into a bacterial expression plasmid for purification of recombinant protein. Recombinant human eIF4H (heIF4H) was purified to greater than 95% homogeneity and shown to have similar physical characteristics to eIF4H purified from rabbit reticulocyte lysate as described previously. Functional studies have revealed that recombinant heIF4H functions identically to rabbit eIF4H in stimulating protein synthesis, and the ATP hydrolysis and helicase activities of eIF4A. More detailed enzymatic studies revealed that eIF4H increases the affinity of eIF4A for RNA by 2-fold, but has no effect on the binding of ATP by eIF4A. eIF4H stimulates the helicase activity of eIF4A at least 4-fold, and it is postulated that this stimulation occurs through increasing the processivity of eIF4A. Northern blot analysis shows that eIF4H is expressed ubiquitously in human tissues, and displays different levels of expression in given tissues relative to eIF4B. Secondary structure analysis of heIF4H by circular dichroism suggest that eIF4H has a mostly β-sheet structure, which appears similar to other RNA recognition motif-containing proteins. Finally, it is suggested that eIF4H functions in translation initiation through protein-protein interactions that possibly stabilize conformational changes that occur in eIF4A during RNA binding, ATP hydrolysis, and RNA duplex unwinding.
Analysis of natural convection about a vertical plate embedded in a porous medium

Abstract Buoyancy-driven fluid flow and heat transfer about a vertical flat plate embedded in a porous medium are analyzed in depth for two general cases. These are the constant wall temperature case and the constant wall heat flux case. By an order of magnitude analysis it is shown that there are two governing dimensionless parameters which are related to the thermal and viscous effects. These are Ra L − 1 2 and Da L 1 2 for the constant wall temperature case and Ra L ∗− 1 3 and Da L 1 2 for the constant wall heat flux case. For each case, two important categories are considered. For the constant wall temperature case these categories are shown to be physically related to either Da L 1 2 ⪡ Ra L − 1 2 ( Da L 1 2 ⪡ Ra L ∗− 1 3 for the constant wall heat flux) or Da L 1 2 ⪢ Ra L − 1 2 ( Da L 1 2 ⪢ Ra L ∗− 1 3 for the constant wall heat flux). The governing equations are solved analytically using the method of matched asymptotic expansions along with the modified Oseen method. The numerical solution of the governing equations based on the similarity transformations is also obtained. It is found that the rate of heat transfer depends on the modified Rayleigh number for Da L 1 2 ⪡ Ra L − 1 2 (or Da L 1 2 ⪡ Ra L ∗− 1 3 ) while the Nusselt number depends on the product of the Rayleigh number and the porosity for Da L 1 2 ⪡ Ra L − 1 2 (or Da L 1 2 ⪡ Ra L ∗− 1 3 ). The heat transfer characteristics for the latter are shown to be independent of the permeability of the porous medium and approaching those of the regular fluid with a high Prandtl number. A complete physical description of the problem is presented throughout the analysis.
Measuring quality in pediatric ophthalmology

Abstract Pediatric ophthalmologists should respond to quality expectations inherent in all disciplines of medicine. The specialists must be able to collect data to document and prove the quality of their work if it anticipates continued reimbursement for services. Quality of medical practice is assessed by outcomes research, which is different from clinical research. All specialists are systemically measuring individual and group outcomes across the spectrum of American health care systems. Pediatric ophthalmologists, both in private practice and at academic centers, must concentrate their research efforts on the assessment of cost, quality, utilization, and patient-centered health-related quality of life for the most common pathologies in pediatric ophthalmology practice. (J AAPOS 1999;3:283-8)
Cross‐examination of the expert witness: Do hostile tactics affect impressions of a simulated jury?

Ninety-one introductory psychology students viewed a videotape of a simulated personal damage trial in which a psychologist expert witness testified about a plaintiff's psychological problems resulting from trauma. The defense attorney's cross-examination tactics, employed against the expert witness, were varied in the videotape. A 2 × 2 factorial design was used, with leading versus nonleading questions and a hostile versus nonhostile attorney. An interaction effect was obtained, in which a hostile attorney using leading questions and a nonhostile attorney using nonleading questions were perceived as least effective. Language: en
Loss of square (orthogonal) arrays from cultured airway epithelial cells

Electron microscopic examination of freeze-fracture replicas reveals distinctive arrangements and planar distributions of certain membrane constituents. In these replicas, the square (orthogonal) array of 6–7-nm intramembranous particles is an easily recognizable membrane differentiation commonly observed in transepithelial ion-transporting epithelia and in several mesenchymal cells, in which they were originally described. Recently, the occurrence, distribution, and number of square arrays have been documented in the lungs of mammals, turtles, and frogs. The current study confirms that there are more than 10 arrays per μm2 basal and lateral portion of the plasma membrane in the alveolar type I and ciliated cells of human, rat, guinea pig, turtle, and frog lung, and in type II pneumocytes of the turtle and frog lung. We have not observed them in mucous cells, brush cells, macrophages, or endothelial cells of any species examined, nor do they appear in the apical portion of the plasma membrane of any airway or alveolar lining cell. Upon elastase or other proteolytic dissociation of the alveolar cells of the mammalian lung, concomitant with breakdown and endocytosis of tight junction strands, the square arrays cluster and are internalized within the membranes of endocytic vesicles that are derived from the lateral and basal portions of the cell. Within 1 day of establishing the cells in tissue culture, tight and gap junctions reappear, but the square arrays do not. Nor do they return to cultures examined on subsequent days. We conclude that the square array is a widespread membrane differentiation throughout the lung and major airways; but extrapolating from results obtained from dog tracheal cells (Widdicombe et al., 1987), the square array configuration of particles is unnecessary for maintaining normal ion transport.
Optimization of environmental parameters for Nannochloropsis salina growth and lipid content using the response surface method and invading organisms.

Algae biofuel has the potential to replace fossil fuels. However, cultivation and productivity of target algae need improvement, while controlling undesired organisms that can lower the efficiency of production systems. A central composite design and response surface model were utilized to predict cultivation optima of marine microalga, Nannochloropsis salina, under a suite of environmental parameters. The effects of salinity, pH, and temperature and their interactions were studied on maximum sustainable yield (MSY, a measure for biomass productivity), lipid content of N. salina, and invading organisms. Five different levels of each environmental predictor variable were tested. The environmental factors were kept within ranges that had previously been determined to allow positive N. salina growth (14.5–45.5 PSU; pH 6.3–9.7; 11–29 °C). The models created for this experiment showed that N. salina’s MSY and lipid content are not strongly affected over the broad range of salinity and temperature values. Calculated optima levels were 28 PSU/20 °C for MSY and 14.5 PSU/20 °C for lipid accumulation, but neither value significantly influenced the model. However, pH was the most important factor to influence algae productivity, and pH optimum was estimated around 8. Both MSY and lipid content were strongly reduced when pH deviated from the optimum. Occurrence of invading organisms seemed stochastic, and none of the environmental factors studied significantly influenced abundance. In conclusion, pH should be kept around 8 for maximum productivity of N. salina. Temperature and salinity should be kept around 20 °C and 28 PSU; however, moderate variations are not too much of a concern and might enhance lipid content of N. salina.
Iron deficiency of soybean in the North Central U.S. and associated soil properties

Abstract Despite extensive research and variety screening efforts, iron deficiency chlorosis is a common, yield-limiting condition for soybean [Glycine max (L.) Merr.] grown in areas with high pH, calcareous soils. In the North Central U.S., total land area where soybean is grown on high pH soils is approximately 1.8 million ha, with iron deficiency responsible for an estimated loss in soybean grain production of 340,000 Mg at a value of $820 million per annum. This is a significant increase in the extent of iron deficiency problems relative to the past because of an expansion of soybean production in the region. Soil properties associated with iron deficiency in this region compared to adjacent areas without iron deficiency include greater soil moisture content and concentrations of soluble salts, carbonates, and DTPA-Cr, and lesser concentrations of DTPA-Fe, Mn, Ni, and Cd. Iron deficiency occurs due to multiple stresses and not simply to limited available iron. Biotic and management factors such as pes...
Teen pregnancy and urban youth: competing truths, complacency, and perceptions of the problem

Abstract Purpose To compare and contrast perceptions of community leaders, adults, and youth about the extent of the teen pregnancy problem in five American cities: Baltimore, Detroit, Oakland, Philadelphia, and Richmond. Methods In the five cities from late 1998 through early 2000, semi-structured telephone interviews were conducted with 79 key informants (leaders influential in children's policy issues) to ascertain their perceptions of the most pressing problems facing youth in their cities. Structured, computer-assisted interviews on a range of issues, including teen childbearing and sexual activity, were conducted with 7716 randomly selected adults and 2768 youth aged 10–18 years. The key informant interviews were transcribed and coded; reviewers were paired to validate the coding. The surveys were analyzed using SPSS. Results Among the key informants, teen pregnancy was cited as a big problem by only 15%; other issues, such as crime and schools, were seen as more pressing. However, 58% of the adults in the general population thought that teen pregnancy was a big problem. Although almost 3/4 of youth in these cities believed their parents would be upset if they had sex, 87% reported that teen sexual activity before age 18 years was acceptable to their peers, 53% said that teen parenthood was considered acceptable, and 51% had at least one friend who was a teen parent. There were statistically significant differences in the adult and youth responses by race, income, and educational attainment. Conclusions Although few leaders see teen pregnancy as a pressing problem, adults remain deeply concerned, and youth indicate that the problem is prevalent and accepted.
The influence of tidal flushing, light exposure and natant macrofauna on edaphic chlorophyll a in a Louisiana salt marsh

Field experiments were designed to test the effects of grass clipping and of exclusion of tidal flushing and natant macrofauna on the concentration of edaphic chlorophyll a in a Spartina alterniflora Loisel. salt marsh in southern Louisiana. The experiment was begun on 28 July 1978 and edaphic chlorophyll a was sampled on days 0, 1, 2, 8, 17 and 29. Large variations were found both over time and within the sampled area on each sample date. However, only the treatment combining grass clipping with tidal and natant macrofaunal exclusion on day 29 showed a significant difference from the control. It appears that tidal flushing is not strong enough, except perhaps during storm surges, to affect edaphic algal levels in this marsh as indicated by chlorophyll a . In addition, clipping of the grass cover was observed to result in a mat of blue-green algae which probably prevented any increase in other types of edaphic algae.
NASAL SALT EXCRETION IN TERRESTRIAL LIZARDS.

Abstract 1. 1. The bilateral nasal salt gland of the terrestrial iguanas Ctenosaura pectinata and Sauromalus obesus secreted fluids containing upto 950 m-equiv K/1 or 190 times more than that in the plasma at flow rates as high as 190 μl/hr. 2. 2. Infusion of methylcholine initiated and IP injection of NaCl stimulated secretion, and IP injection of KCl increased both rate of flow and K concentration of secretion. 3. 3. Clearance rates of K from the plasma measured as high as 15 cm3/hr in Ctenosaura and 5 cm3/hr in Sauromalus. 4. 4. IP injection of NaCl increased K but not Na concentration of the nasal fluid. 5. 5. Na concentration in the fluid remained characteristically below that of the plasma. 6. 6. Excretion of K by the gland compares favorably with renal tubular secretion of K by mammals.
In Vivo Pretreatment with Human Chorionic Gonadotropin Fails to Reverse the Dysfunction of Isolated Leydig Cells from Chronically Uremic Rats

In order to further investigate the previously reported hypogonadal state of chronically uremic rats, we examined the effects of in vivo pretreatment with human chorionic gonadotropin (hCG) on in vivo and in vitro Leydig cell function, comparing paired intact rats with rats made chronically uremic by 5/6 nephrectomy. The in vitro testosterone (T) secretory responses to varying concentrations of hCG or dibutyryl cAMP and the number of gonadotropin receptors were determined following hemicastration. The rats were then treated with hCG for 3 days and the remaining testes were removed and studied as before. Compared with intact rats, the uremic rats had higher serum concentrations of urea nitrogen (P O.6) treatment. Treatment produced increases in serum T only in uremic rats (P 0.8) in both groups after treatment. Baseline in vitro T secretion was lower (P<O.0O1) from Leydig cells of uremic than intact rats both before and after treatment. Analysis of variance of dose-response curves showed pre- and post-treatment T secretory responses to hCG or dibutyryl cAMP in vitro to be less from Leydig cells of uremic rats (P<0.01). Before treatment, Leydig cell gonadotropin receptor number was lower in uremic than intact rats (P<0.01). Down-regulation of receptor number was observed after hCG treatment in both groups (P<0.O1), but receptor number remained significantly lower on cell membranes from the uremic rats (P<0.01). The coexistent finding of reduced levels of serum luteinizing hormone and T in uremic rats and reversibility of hypoandrogenemia by in vivo hCG treatment would suggest that the hypogonadism of uremic rats is due to effects of uremia on hypothalamic-pituitary function. However, our findings that Leydig cells from chronically uremic rats exhibit marked deficits in basal and stimulated in vitro T secretion, not reversed by 3 days of in vivo gonadotropin administration, and decreased numbers of gonadotropin receptors suggest that uremia may produce one or more intrinsic derangements of Leydig cell function, independent of its effects on gonadotropin secretion.
Effects of divalent and trivalent cations on Na+-Ca2+ exchange in cardiac sarcolemmal vesicles

Inhibition of Na+-Ca2+ exchange processes in canine cardiac sarcolemmal vesicles by several divalent and trivalent cations has been investigated. The order of cation effectiveness in inhibiting initial rates of Nai+-induced Ca2+ uptake in the presence of 140 mM Nai+ and 20 microM Cao2+ is La3+ greater than Nd3+ greater than Tm3+ approximately Y3+ greater than Cd2+ much greater than Sr2+ greater than Ba2+ approximately Mn2+ much greater than Mg2+. The effectiveness of the divalent ions is related to their ionic crystal radius as compared with that of Ca2+. No such relationship was observed for the trivalent ions, which appeared instead to be more effective the larger their radius. Very low concentrations of trivalent ions ((1-6).10(-7)M) caused slight stimulation of Ca2+-exchange uptake. The trivalent ions also inhibited passive and Nao+-induced Ca2+ efflux from sarcolemmal vesicles, in the same concentration range as that for inhibiting uptake. The divalent ions, however, stimulated Ca2+ efflux, possibly via divalent cation-Ca2+ exchange. These various results suggest that the divalent and trivalent cations interact differently with the exchange apparatus in the sarcolemma.
Delta-tetrahydrocannabinol suppresses macrophage costimulation by decreasing heat-stable antigen expression

Delta9-tetrahydrocannabinol (THC) suppresses several immunologic functions of macrophages. The costimulatory activity of a THC-exposed macrophage hybridoma was investigated by its ability to elicit interleukin-2 secretion by a helper T cell hybridoma activated with immobilized monoclonal anti-CD3 antibody. THC added at culture initiation inhibited the T cell response in a dose-dependent manner. When the macrophages were fixed with paraformaldehyde before culture, THC had no effect on T cell stimulation. However, macrophages, which were preincubated with THC and then fixed, were impaired in delivering costimulatory signals to T cells cultured without THC. The drug's inhibitory effect on macrophage costimulatory activity was reversible. THC exposure also decreased macrophage expression of heat-stable antigen (HSA). Antibody blocking experiments showed that HSA expressed on the macrophages provided an important costimulatory signal, whereas B7-1 and B7-2 molecules had a minor role. Treatment of the macrophages with phosphatidylinositol-specific phospholipase C cleaved HSA, but not the transmembrane B7 molecules, from the cell surface. Similar to THC, enzyme treatment significantly diminished macrophage costimulatory activity, which was also reversible. After drug or enzyme removal, HSA expression returned to the control level by 4 h. Therefore, THC suppresses macrophage costimulatory activity by diminishing cell surface expression of HSA.
The effect of a zirconium strength differential on cladding collapse predictions

Abstract An investigation was made into the occurrence of a strength differential in the Zircaloy cladding of LWR fuels, and into the effect such a strength differential can have on the analytical predictions of cladding creep collapse during fuel densification. The strength differential, or SD, refers to the difference in the compressive and tensile yield strengths of a material. It was concluded that an SD in Zircaloy cladding can have a significant effect on cladding collapse predictions; inclusion of SD considerations in cladding creep down analysis can increase predicted collapse times by a factor of two.
Finite element model predictions of static deformation from dislocation sources in a subduction zone: Sensitivities to homogeneous, isotropic, Poisson-solid, and half-space assumptions

[1] Dislocation models can simulate static deformation caused by slip along a fault. These models usually take the form of a dislocation embedded in a homogeneous, isotropic, Poisson-solid half-space (HIPSHS). However, the widely accepted HIPSHS assumptions poorly approximate subduction zone systems of converging oceanic and continental crust. This study uses three-dimensional finite element models (FEMs) that allow for any combination (including none) of the HIPSHS assumptions to compute synthetic Green's functions for displacement. Using the1995 Mw = 8.0 Jalisco-Colima, Mexico, subduction zone earthquake and associated measurements from a nearby GPS array as an example, FEM-generated synthetic Green's functions are combined with standard linear inverse methods to estimate dislocation distributions along the subduction interface. Loading a forward HIPSHS model with dislocation distributions, estimated from FEMs that sequentially relax the HIPSHS assumptions, yields the sensitivity of predicted displacements to each of the HIPSHS assumptions. For the subduction zone models tested and the specific field situation considered, sensitivities to the individual Poisson-solid, isotropy, and homogeneity assumptions can be substantially greater than GPS measurement uncertainties. Forward modeling quantifies stress coupling between the Mw = 8.0 earthquake and a nearby Mw = 6.3 earthquake that occurred 63 days later. Coulomb stress changes predicted from static HIPSHS models cannot account for the 63-day lag time between events. Alternatively, an FEM that includes a poroelastic oceanic crust, which allows for postseismic pore fluid pressure recovery, can account for the lag time. The pore fluid pressure recovery rate puts an upper limit of 10−17 m2 on the bulk permeability of the oceanic crust.
Quantitation of DNA Sequences in Environmental PCR Products by a Multiplexed, Bead-Based Method

A first application of a multiplexed, bead-based method is described for determining the abundances of target sequences in an environmental PCR product. Target sequences as little as 0.3% of the total amount of DNA can be quantified. Tests were conducted on 16S ribosomal DNA sequences from microorganisms collected from contaminated groundwater.
Striatum specific protein, Rhes regulates AKT pathway

The Rhes/RASD2 GTPase complex is involved in dopamine D1/D2 receptor-mediated signaling and behavior. This GTP binding protein belongs to the RAS superfamily, along with Dexras1/RASD1, and is primarily expressed in the striatum. RASDs differ from typical small GTPases as they have an extended C-terminal tail of roughly 7 kDa. Previously, it has been shown that dopamine depletion reduces Rhes mRNA expression in the brain. Here we show that Rhes interacts with p85, the regulatory subunit of PI3K. Specifically, the C-terminal unique tail region of Rhes is responsible for this interaction. The interaction between p85 and the C-terminal region of Rhes is enhanced upon growth factor treatment in vitro, while AKT translocation to the membrane is facilitated in the presence of Rhes or the Rhes-p85 complex. These findings suggest that Rhes is a novel striatal regulator of the AKT-mediated pathway in the striatum.
Stability of State Feedback Transformations for Nonlinear Systems - Some Practical Considerations

A number of methods have been recently proposed for the feedback transformation of nonlinear systems. This paper describes some practical considerations in their application to process systems and, in particular, the signifance of local controllability. The example considered is the van de Vusse reaction carried out in an isothermal stirred tank reactor. It is shown that exact linearization is not appropriate because the controllability condition breaks down in the neighborhood of a steady operating point.
Current concepts in minimally invasive surgery of the abdomen.

Minimally invasive surgery of the abdomen constitutes an increasingly common and developed set of surgical options in small animal veterinary patients. In addition to established procedures, such as laparoscopic gonadectomy and biopsies, more advanced procedures, such as adrenalectomy, cholecystectomy, cisterna chyli ablation, and lymph node extirpation, are described. Some laparoscopic procedures have been reported using different techniques or approaches, reflecting the field’s progression beyond its infancy. Advances in equipment and experience among an ever-growing group of veterinary surgeons are expected to result in progressively more widespread adoption of minimally invasive procedures.
Hepatic metabolism and transport in thiamine deficiency.

Thiamine deficiency often accompanies alcoholism which causes liver disease, but the role of thiamine depletion per se in modifying hepatic metabolism and function is uncertain. Thiamine is the coenzyme for transketolase and pyruvate decarboxylase in tissues. Decreased pyruvate decarboxylase activity theoretically may impair synthesis of acetyl CoA and then of ATP, the ultimate tissue energy source. In this study, hepatic metabolism, especially ATP stores, and the transport of Rose Bengal across the liver, were assessed in rats with encephalopathy due to dietary thiamine deprivation, and in asymptomatic pair-fed controls. Compared to controls, in the thiamine-deficient rats, (a) hepatic transketolase and pyruvate decarboxylase activity were 89 and 74% lower (P<0.01) respectively; however, (b) hepatic acetyl CoA and ATP concentrations decreased only 21 and 12% (P<0.01), hepatic morphology was normal, and transport of Rose Bengal-131l across the liver was unimpaired. Depressed hepatic pyruvate decarboxylase activity and ATP concentration in thiamine-deficient rats in vivo responded to exogenous thiamine much more slowly than it did in brain, heart or kidney. In vitro, however, hepatic pyruvate decarboxylase activity rose briskly when exogenous thiamine pyrophosphate was added, indicating that the apoenzyme was not impaired. In conclusion, in severe thiamine deficiency, hepatic acetyl CoA and ATP stores are only slightly decreased, and hepatic transport of Rose Bengal is normal.