cssi/SciSciGPT-SciSciNet huggingface dataset:
Materials fabrication via polymerizable selforganized membranes: An overview

Abstract Molecular self-assembly of amphiphilic phospholipid molecules (containing a hydrophobic acyl chain and a hydrophilic phosphate group attached to glycerol backbone) and other amphiphiles offers a versatile approach to form ordered structures such as vesicles and lipid microcylinders. Stabilization of lipid microstructures by polymerization renders them useful for practical applications in the areas ranging from controlled release technology to template mediated synthesis of metals. Our efforts are focussed on the fabrication and use of derived microstructures from polymerizable diacetylenic phospholipids as templates for making advanced materials. The surfaces of the phospholipid membrane templates consist of the hydrophilic headgroup region of phospholipids that are made active by chemical modification. Phospholipids with chemically reactive sites were incorporated into lipid membranes formed from negatively charged and charge neutral phospholipids and used for binding metal ions and growing fine metal particles.
Dione’s resurfacing history as determined from a global impact crater database

Saturn’s moon Dione has an interesting and unique resurfacing history recorded by the impact craters on its surface. In order to further resolve this history, we compile a crater database that is nearly global for diameters (D) equal to and larger than 4 km using standard techniques and Cassini Imaging Science Subsystem images. From this database, spatial crater density maps for different diameter ranges are generated. These maps, along with the observed surface morphology, have been used to define seven terrain units for Dione, including refinement of the smooth and “wispy” (or faulted) units from Voyager observations. Analysis of the terrains’ crater size–frequency distributions (SFDs) indicates that: (1) removal of D ≈ 4–50 km craters in the “wispy” terrain was most likely by the formation of D ≳ 50 km craters, not faulting, and likely occurred over a couple billion of years; (2) resurfacing of the smooth plains was most likely by cryovolcanism at ∼2 Ga; (3) most of Dione’s largest craters (D ⩾ 100 km), including Evander (D = 350 km), may have formed quite recently (<2 Ga), but are still relaxed, indicating Dione has been thermally active for at least half its history; and (4) the variation in crater SFDs at D ≈ 4–15 km is plausibly due to different levels of minor resurfacing (mostly subsequent large impacts) within each terrain.
Thermal response behavior of laminar boundary layers in wedge flow

Abstract The thermal response behavior of incompressible, uniform property, laminar boundary layer flows over wedges has been investigated using a technique recently proposed by Chao and Cheema. Both the surface response characteristics and details of the transient temperature fields, subsequent to a step change in either the surface temperature or surface heat flux, are obtained. Results are presented for Prandtl numbers of 0·01, 0·1,0·72, 1·0, 10 and 100 and for wedges with β = −·1, 0, 0·1, 0·2, 0·5 and 1·0, πβ being the wedge angle. Revealing physical insight is gained by comparing the data for small times with pure conduction transients and the steady state data with those deduced for vanishingly small Prandtl number and for large Prandtl number.
Slow photoelectron velocity-map imaging spectroscopy of cold negative ions

Anion slow photoelectron velocity-map imaging (SEVI) spectroscopy is a high-resolution variant of photoelectron spectroscopy used to study the electronic and geometric structure of atoms, molecules, and clusters. To benefit from the high resolution of SEVI when it is applied to molecular species, it is essential to reduce the internal temperature of the ions as much as possible. Here, we describe an experimental setup that combines a radio-frequency ion trap to store and cool ions with the high-resolution SEVI spectrometer. For C(5)(-), we demonstrate ion temperatures down to 10 ± 2 K after extraction from the trap, as measured by the relative populations of the two anion spin-orbit states. Vibrational hot bands and sequence bands are completely suppressed, and peak widths as narrow as 4 cm(-1) are seen due to cooling of the rotational degrees of freedom.
Piecewise linear slope estimation

This paper presents a method for directly estimating slope values in a noisy piecewise linear function. By imposing a Markov structure on the sequence of slopes, piecewise linear fitting is posed as a maximum a posteriori estimation problem. A dynamic program efficiently solves this by traversing a linearly growing trellis. The alternating maximization algorithm (a kind of pseudo-EM method) is used to estimate the model parameters from data and its convergence behavior is analyzed. Ultrasound shear wave imaging is presented as a primary application. The algorithm is general enough for applicability in other fields, as suggested by an application to the estimation of shifts in financial interest rate data.
Hepatitis B virus particles of plasma and liver contain viral DNA-RNA hybrid molecules.

Abstract Hepatitis B virions in plasma (Dane particles) are known to contain small circular DNA molecules. The experiments described here indicate that virions in plasma, as well as particles from hepatitis B virus-infected human liver, also contain viral DNA-RNA hybrid molecules, and deoxynucleotides can be incorporated into the DNA of these hybrids by DNA polymerase activities in the virions. Thus, two viral DNA synthetic reactions appear to take place in virions: repair of the single-stranded region of circular DNA molecules and synthesis or elongation of the DNA strand of DNA-RNA hybrid molecules. Centrifugation of virion nucleic acid to equilibrium in Cs 2 SO 4 density gradients revealed the presence of viral DNA-RNA hybrid molecules over a density range of 1.45 to 1.60 g/cm 3 . Distinct species of hybrid molecules were found with an average density of 1.57 g/cm 3 in Dane particles and 1.52 and 1.57 g/cm 3 in particles from liver. Fractionation of nucleic acid from Cs 2 SO 4 density gradients by gel electrophoresis demonstrated that the majority of hybrid molecules migrated faster than molecules with the density of pure DNA (1.42 g/cm 3 ). One notable exception was the finding of DNA-RNA hybrid molecules migrating slower than open circular viral DNA. Characterization of viral DNA-RNA hybrids by heat denaturation Cs 2 SO 4 density gradient fractionation, and recombinant ] single-stranded probe hybridization revealed that the hybrid molecules consisted of viral plus-strand RNA hydrogen bonded to viral minus-strand DNA sequences. Data obtained by pancreatic ribonuclease digestion revealed that the hybrid molecules at density 1.45 to 1.52 g/cm 3 contained HBV RNA strands base paired over only part of their length in contrast to the hybrid species at density 1.57 g/cm 3 which contained RNA strands apparently base paired over most of their length. Further characterization showed that the hyrid at 1.57 g/cm 3 contained genome-length minus-strand viral DNA. The experiments rule out the possibility that the hybrid molecules are transcriptional complexes. Data presented in a companion manuscript indicate that the hybrid molecules may represent intermediates in the synthesis of viral DNA in the endogenous DNA polymerase reaction.
Putrescine and certain polyamines can inhibit DNA injection from bacteriophage lambda.

Abstract The injection of λDNA from attached phage into a host bacterium can be reversibly inhibited by putrescine. The concentration of di- or polyamine required to inhibit injection varies with the Mg2+ concentration and the amount of DNA in the phage head. In a series of n-alkyl diamines, those with more than five or fewer than three CH2 groups between amino groups were ineffective.
Dispersions of the third-order nonlinear optical susceptibilities χ1111(3)(ω;ω,0,0) and χ2211(3)(ω;ω,0,0) of a polydiacetylene film

Abstract The dispersions of the in-plane components χ 1111 (3) ( ω ; ω ,0,0) and χ 2211 (3) ( ω ; ω ,0,0) of a spin coated polydiacetylene film (poly(4-BCMU)) were determined through electroabsorption spectroscopy with interdigital electrodes. The maximum values of real part and imaginary part of χ 1111 (3) ( ω ; ω ,0,0) are 1.69×10 −10 esu and 1.24×10 −10 esu, respectively, and the maximum values of real part and imaginary part of χ 2211 (3) ( ω ; ω ,0,0) are 6.2×10 −11 esu and 4.2×10 −11 esu, respectively. The spectra of these two components are similar, and the ratio of χ 1111 (3) ( ω ; ω ,0,0) to χ 2211 (3) ( ω ; ω ,0,0) is found to be 2.8, very close to 3, indicating an in-plane isotropy.
An algorithm for evaluating stable densities in Zolotarev's (M) parameterization

One of the major obstacles to the use of stable distributions in applications is the lack of formulas for their densities. A program is described to calculate a general @a-stable density for @a > 0.75 and any skewness value @b.
Skating on thin ice

Aortic dissection is an uncommon but potentially catastrophic disorder. It typically occurs in older patients but can be seen in younger patients (usually with predisposing conditions). Aortic dissections can be classified into 2 types: type A dissections that involve the ascending aorta and type B dissections that do not involve the ascending aorta. We report a case of a teenager with a type B aortic dissection after a seemingly trivial inciting event. This article reviews important features of aortic dissection including diagnosis and management.
Gas diffusivity and permeability through the firn column at Summit, Greenland: measurements and comparison to microstructural properties

The physical structure of polar firn plays a key role in the mechanisms by which glaciers and ice sheets preserve a natural archive of past atmospheric composition. This study presents the first measurements of gas diffusivity and permeability along with microstructural information measured from the near-surface firn through the firn column to pore close-off. Both fine- and coarse-grained firn from Summit, Greenland are included in this study to investigate the variability in firn caused by seasonal and storm-event layering. Our measurements reveal that the porosity of firn (derived from density) is insufficient to describe the full profiles of diffusivity and permeability, particularly at porosity values above 0.5. Thus, even a model that could perfectly predict the density profile would be insufficient for application to issues involving gas transport. The measured diffusivity profile presented here is compared to two diffusivity profiles modeled from firn air measurements from Summit. Because of differences in scale and in firn processes between the true field situation, firn modeling, and laboratory measurements, the results follow a similar overall pattern but do not align; our results constitute a lower bound on diffusive transport. In comparing our measurements of both diffusivity and permeability to previous parameterizations from numerical 3-D lattice-Boltzmann modeling, it is evident that the previous relationships to porosity are likely site-specific. We present parameterizations relating diffusivity and permeability to porosity as a possible tool, though use of direct measurements would be far more accurate when feasible. The relationships between gas transport properties and microstructural properties are characterized and compared to existing relationships for general porous media, specifically the Katz–Thompson (KT), Kozeny–Carman (KC), and Archie's law approximations. While those approximations can capture the general trend of gas transport relationships, they result in high errors for individual samples and fail to fully describe firn variability, particularly the differences between coarse- and fine-grained firn. We present a direct power law relationship between permeability and gas diffusivity based on our co-located measurements; further research will indicate if this type of relationship is site-specific. This set of measurements and relationships contributes a unique starting point for future investigations in developing more physically based models of firn gas transport.
The Morphologic Effects of Vincristine Sulfate on Canine Bone Marrow Cells

This study documents the morphologic changes observed in the bone marrow aspirate biopsies from dogs 6 and 24 hours after receiving a single therapeutic dose (0.025 mg/kg) of vincristine sulfate (Oncovin: Eli Lilly & Co., Indianapolis, Ind.) intravenously. The most striking cytologic changes were observed in the erythroid cell line. Abnormalities included increased numbers of mitotic figures, abnormal nuclear configurations, and fragmented nuclei. Erythroid cells in metaphase were prominent in marrow samples collected 6 hours post-vincristine, accounting for a mean of 27% of all erythroid precursors. Fragmented nuclei and atypical nuclear configurations were seen in low numbers (mean = 7%) of erythroid cells from these animals. In contrast, marrow collected from dogs 24 hours post-vincristine exhibited low numbers (mean = 1%) of erythroid cells in metaphase, but erythroid cells with atypical nuclear configurations and fragmented nuclei accounted for a mean of 41 % of the erythroid cells present. Less dramatic increases in the number of mitotic non-erythroid cells were seen 6 hours post-vincristine (mean = 5% of non-erythroid cells) and 24 hours post-vincristine (mean = 1% of non-erythroid cells). Only rare nuclear fragmentation was observed in these cell lines. Significant alterations in megakaryocytes and myeloid to erythroid (M:E) ratios were not observed in samples taken 6 hours post-vincristine; however, M:E ratios were considerably higher in three of the four samples taken from dogs 24 hours post-vincristine. Similar time-related changes were observed in four clinical cases in which bone marrow aspirates were performed after vincristine administration.
Germ cell nuclear factor

Germ cell nuclear factor (GCNF) is an orphan nuclear receptor for which a ligand has yet to be identified. However, we do know that GCNF binds to a novel response element as a homodimer and regulates expression of genes, such as the protamines, through this element. In the absence of a ligand, GCNF is a transcriptional repressor that interacts with co-repressors. During embryonic development, GCNF is expressed between the gastrula and neurula stages. Loss of GCNF causes embryonic lethality, disrupts normal somitogenesis, as well as neural tube and axis formation, suggesting that GCNF is a critical factor for normal embryonic development. In adult vertebrates, GCNF expression is predominantly found in the germ cells of gonads. GCNF expression in germ cells suggests that understanding its function in adults will yield greater insight into the regulation of gametogenesis, leading to new contraceptive targets.
Nosocomial transmission and infection control aspects of parasitic and ectoparasitic diseases. Part III. Ectoparasites/summary and conclusions.

The ectoparasites of potential nosocomial significance include the pediculoses (head, body, and pubic lice), scabies and certain other mites, and myiasis. Head lice, pubic lice, and scabies are common in the United States and appear to be increasing in incidence. These infestations will continue to be seen as an incidental problem in hospitalized patients. The risks and fears of nosocomial transmission of ectoparasites to other patients and staff are often exaggerated, although scabies does have the potential to cause large hospital outbreaks. PEDICULOSES
Electronic structure and equilibrium properties of GaxAl1-xN alloys.

First-principles calculations by means of the linear-muffin-tin-orbital method were carried out of the electronic band structures, equilibrium lattice constants, energies of formation, and bulk moduli of Ga x Al 1-x N alloys in zinc-blende-derived structures with a specific cation ordering. The miscibility and band-gap bowing of disordered alloys were studied using a cluster expansion method. Complete mutual solubility is predicted to occur at typical growth temperatures. The band gap is found to exhibit a weak bowing and to change from being indirect (Γ→X) for x=0 to direct at Γ at a concentration of x≃0.4
Decreasing the Incidence of Deep Vein Thrombosis Through the Use of Prophylaxis

Every year, thousands of patients develop deep vein thrombosis (DVT) after undergoing surgery. Deep vein thromboses that result in pulmonary embolisms (PEs) are believed to be one of the most frequently occurring, preventable killers of hospitalized patients. Strategies for preventing a patient from developing DVT include implementing chemical or mechanical prophylaxis or a combination of the two. By instituting a DVT-assessment program, implementing mechanical DVT prophylaxis, and educating nurses and patients, the incidence of DVTs in orthopedic patients can be reduced, leading to fewer deaths from PEs.
SMOKELESS TOBACCO USE: How It Affects the Performance of Major League Baseball Players

The authors examined the effect of smokeless tobacco use on the athletic performance of major league baseball players during the 1988 season. They evaluated performance records of 158 players on seven major league teams who played or pitched at least 10 games or innings during the 1988 season. ST use, they concluded, is not related to player performance in major league baseball but does place players at significantly increased risk for mucosal lesions and other oral pathology.
Analysis of tandem mass spectra by FTMS for improved large-scale proteomics with superior protein quantification.

Using a newly developed dual-cell quadrupole linear ion trap−orbitrap hybrid mass spectrometer (dcQLT−orbitrap), we demonstrate the utility of collecting high-resolution tandem mass spectral data for large-scale shotgun proteomics. Multiple nanoLC−MS/MS experiments on both an older generation quadrupole linear ion trap−orbitrap hybrid (QLT−orbitrap) and the dcQLT−orbitrap, using both resonant-excitation CAD and beam-type CAD (HCD), were performed. Resulting from various technological advances (e.g., a stacked ring ion guide AP inlet, a dual cell QLT), the dcQLT−orbitrap exhibited increased duty cycle (∼1.5−2 times) and sensitivity for both CAD (ion trap detection) and HCD (orbitrap detection) methods. As compared to the older system, the dcQLT−orbitrap produced significantly more unique peptide identifications for both methods (∼30% improvement for CAD and ∼115% improvement for HCD). The sizable improvement of the HCD method on the dcQLT−orbitrap system outperforms the current standard method of CAD with ...
EFFECTS OF ORGANIC SOLVENTS ON USE OF TARBUSH BY SHEEP

Tarbush (Flourensia cernua DC) is a native perennial shrub prevalent in many parts of the Chihuahuan Desert. Ruminants have exhibited limited use of tarbush leaves and new leaders as a forage during the summer growing season. Efforts to increase use of tarbush by lambs through spraying with various organic solvents were unsuccessful, probably because of the highly variable response. However, complete immersion of tarbush in organic solvents (acetone and ethanol) increased (P<0.01) tarbush use by ram lambs when compared to unaltered tarbush. Data suggest that removal of secondary compounds from the leaf surface of tarbush using organic solvents enhanced acceptability of tarbush to sheep.
Design of partially replicated distributed database systems: an integrated methodology

The objective of this research is to develop and integrate tools for the design of partially replicated distributed database systems. Many existing tools are inappropriate for designing large-scale distributed databases due to their large computational requirements. Our goal is to develop tools that solve the design problems reasonably quickly, typically by using heuristic algorithms that provide approximate or near-optimal solutions.In developing this design methodology, we assume that information regarding the types of user requests and their rates of arrival into the system is known a priori. The methodology assumes a general model for transaction execution. In this paper we discuss three aspects of the design methodology: the data allocation problem, the use of a static load-balancing scheme in coordination with the allocation scheme, and the design evaluation and review step. Our methodology employs iterative design techniques using performance evaluation as a means to iterate.
Constraints on the formation of the Martian crustal dichotomy from remnant crustal magnetism

The Martian crustal dichotomy characterizing the topographic difference between the northern and southern hemispheres is one of the most important features on Mars. However, the formation mechanism for the dichotomy remains controversial with two competing proposals: exogenic (e.g., a giant impact) and endogenic (e.g., degree-1 mantle convection) mechanisms. Another important observation is the Martian crustal remnant magnetism, which shows a much stronger field in the southern hemisphere than in the northern hemisphere and also magnetic lineations. In this study, we examine how exogenic and endogenic mechanisms for the crustal dichotomy are constrained by the crustal remnant magnetism. Assuming that the dichotomy is caused by a giant impact in the northern hemisphere, we estimate that the average thickness of ejecta in the southern hemisphere is 20–25 km. While such a giant impact may cause crustal demagnetization in the northern hemisphere, we suggest that the impact could also demagnetize the southern hemisphere via ejecta thermal blanketing, impact demagnetization, and heat transfer from the hot layer of ejecta, thus posing a challenge for the giant impact model. We explore how the pattern of magnetic lineations relates to endogenic theories of dichotomy formation, specifically crustal production via degree-1 mantle convection. We observe that the pattern of lineations roughly corresponds to concentric circles about a single pole, and determine the pole for the concentric circles at 76.5 E and 84.5 S, which nearly overlaps with the centroid of the thickened crust in the southern hemisphere. We suggest that the crustal magnetization pattern, magnetic lineations, and crustal dichotomy (i.e., thickened crust in the highlands) can be explained by a simple endogenic process; one-plume convection causes melting and crustal production above the plume in the southern hemisphere, and strong crustal magnetization and magnetic lineations are formed in the southern hemisphere as crustal production fronts spread radially out from the plume center and as the newly created crust cools in the presence of a dynamo with polarity reversals.
MULTIAGE PROGRAMMING EFFECTS ON COGNITIVE DEVELOPMENTAL LEVEL AND READING ACHIEVEMENT IN EARLY ELEMENTARY SCHOOL CHILDREN

Differences in cognitive developmental level and reading achievement of elementary school children in multiage programming and traditional classrooms were explored. There is controversy regarding the benefit of multiage classrooms for learning academic subjects. According to previous research (e.g., Almy, Chittenden, & Miller, 1967; Brekke, Williams, & Harlow, 1973; Cromey, 1999), cognitive developmental level, reading achievement, and classroom type all seem to be related entities. This study assesses the effects of multiage classrooms compared to traditional classrooms on cognitive developmental level and reading ability of kindergartners, first graders, and second graders. The effects of cognitive developmental level on reading ability were also explored. The results support the connections among cognitive developmental level, reading ability, and classroom type.
Time-dependent Bs0– mixing using inclusive and semileptonic B decays at SLD

Abstract We have searched for time-dependent B s 0 – B s 0 mixing using a sample of 400 000 hadronic Z 0 decays collected by the SLD experiment at the SLC. The analyses take advantage of the excellent vertexing efficiency and resolution of the pixel-based CCD Vertex Detector which provides a B decay length resolution of approximately 100 μm . All analyses determine the B hadron flavor at production by exploiting the large forward–backward asymmetry of polarized Z 0 → b b decays. This flavor tag is enhanced by incorporating additional information from the hemisphere opposite that of the reconstructed B decay. In one analysis, B decay vertices are reconstructed inclusively with a topological technique, and separation between B s 0 and B s 0 decays is based on the reconstruction of a “charge dipole” of the topological vertices to exploit the B s 0 →D s − cascade charge structure. The other two analyses select semileptonic decays to tag the B flavor at decay and reconstruct the B decay vertex by intersecting the lepton with either all tracks in the nearest jet or the trajectory of a topologically reconstructed D vertex. The three analyses are combined to exclude the following values of the oscillation frequency: Δ m s 6.0 ps −1 Δ m s ps −1 . Future prospects are outlined.
Hinged, pseudo-grid triangulation method for long, near-linear cliff analyses

AbstractLight detection and ranging (LIDAR) scanners can rapidly collect high-resolution, centimeter-level-accurate point clouds representing topography, suitable for change detection if scans are repeated over time. To perform meaningful volumetric change analyses, point clouds are commonly triangulated to produce continuous, digital terrain models (DTMs). However, DTM creation methods generally require a fixed-look direction tied to a specific plane, which results in less than ideal triangulations when modeling areas with largely varying topography, such as coastal cliffs and beaches. Furthermore, for accurate volumetric change analysis, surfaces must be free of intersecting triangles, have consistent facet-normal orientations, and be free of data gaps (holes). The methodology presented herein produces continuous surfaces without inconsistent normals and minimizes holes and self-intersections. The few intersecting triangles and holes may be quickly repaired using existing algorithms and were shown to be...
A Detailed Characterization of the Dysfunctional Immunity and Abnormal Myelopoiesis Induced by Severe Shock and Trauma in the Aged

The elderly are particularly susceptible to trauma, and their outcomes are frequently dismal. Such patients often have complicated clinical courses and ultimately die of infection and sepsis. Recent research has revealed that although elderly subjects have increased baseline inflammation as compared with their younger counterparts, the elderly do not respond to severe infection or injury with an exaggerated inflammatory response. Initial retrospective analysis of clinical data from the Glue Grant trauma database demonstrated that despite a similar frequency, elderly trauma patients have worse outcomes to pneumonia than younger subjects do. Subsequent analysis with a murine trauma model also demonstrated that elderly mice had increased mortality after posttrauma Pseudomonas pneumonia. Blood, bone marrow, and bronchoalveolar lavage sample analyses from juvenile and 20-24-mo-old mice showed that increased mortality to trauma combined with secondary infection in the aged are not due to an exaggerated inflammatory response. Rather, they are due to a failure of bone marrow progenitors, blood neutrophils, and bronchoalveolar lavage cells to initiate and complete an emergency myelopoietic response, engendering myeloid cells that fail to clear secondary infection. In addition, elderly people appeared unable to resolve their inflammatory response to severe injury effectively.
DISSIPATIVE DISCRETIZATION METHODS FOR APPROXIMATIONS TO THE BOLTZMANN EQUATION

This paper deals with the spatial discretization of partial differential equations arising from Galerkin approximations to the Boltzmann equation, which preserves the entropy properties of the original collision operator. A general condition on finite difference methods is derived, which guarantees that the discrete system satisfies the appropriate equivalent of the entropy condition. As an application of this concept, entropy producing difference methods for the hydrodynamic model equations and for spherical harmonics expansions are presented.
Selection, adaptation, and bacterial operons.

Bacteria are especially useful as systems to study the molecular basis of adaptive evolution. Selection for novel metabolic capabilities has allowed us to study the evolutionary potential of organi...
Dynamic test data transformations for average and peak power reductions

Parallel test application helps reduce the otherwise considerable test times in SoCs; yet its applicability is limited by average and peak power considerations. The typical test vector loading techniques result in frequent transitions in the scan chain, which in turn reflect into significant levels of circuit switching unnecessarily. Judicious utilization of logic in the scan chain can help reduce transitions while loading the test vector needed. The transitions embedded in both test stimuli and the responses are handled through scan chain modifications consisting of logic gate insertion between scan cells as well as inversion of capture paths with no performance degradation. To reduce average and peak power, we herein propose computationally efficient schemes that identify the location and the type of logic to be inserted. The experimental results confirm the significant reductions in test power possible under the proposed scheme.
tert.‐Butyl aminocarbonate (tert.‐butyloxycarbonyloxyamine) — a new acylating reagent for amines

tert.-Butyl amino carbonate (1, tert.-butyloxycarbonyloxyamine) was prepared by reaction of hydroxylamine with di-tert.-butyl dicarbonate (2). 1 was used to acylate different amino acids or amines in water or in aqueous dioxane. 1 was also prepared in situ and used to acylate amino acids directly. 1 reacted 1.5-2.5 times faster than 2 with all amines studied either in water or 50% (v/v) dioxane. Remarkably, 1 retained its ability to acylate amines even in acid solution; the rate of acylation of L-Phe at pH 6.5 (15 M-1 X min-1) was about 20% of the rate at pH 10 (72 M-1 X min-1). 2 was not an acylating reagent below pH 7.0 and as expected, the rate at pH 8.3 (4 M-1 X min-1) was about 10% of that at pH 9.3 (39 M-1 X min-1). Pure BOC-amino acids were obtained in high yield and could be quantitatively deprotected by standard procedures.
Peoples of the Gran Chaco

Peoples of the Gran Chaco. Elmer S. Miller. ed. Westport, CO: Bergin and Garvey, 1999. vii. 166 pp., illustrations, maps, photographs, index.
Impact of Local Morphology on Sedimentation in a Submarine Canyon, ROV Studies in Eel Canyon, Northern California, U.S.A.

Abstract Despite existing paradigms about marine sedimentation, some submarine canyons are receiving large amounts of sediment during the present highstand of sea level. These modern examples can be used to unlock secrets of past canyon sedimentation. However, submarine canyons have complex morphology, and consequently dramatic variations in sedimentary processes and deposits can occur over a range of spatial scales as small as meters to tens of meters. Operations from surface ships usually cannot place sampling devices on the canyon seabed with this level of accuracy. The purpose of the present study was to investigate the variability of sedimentation over a range of scales, in order to delineate accurate trends along and among channels at the head of a canyon. Sampling with the ROV Ventana facilitated detailed examination of microenvironments (i.e. wall, thalweg) in Eel submarine canyon. The combination of intense sedimentation from nepheloid layers and gravity flows in a complicated morphologic system leads to clear distinctions between microenvironments, as well as some recognizable and unifying trends in sedimentation. Inherent small-scale variability due to canyon morphology is evident in narrow and steep channels. At 1-m horizontal resolution, cores exhibit consistent sediment fabric, but laminae can differ between cores. At the 10-m horizontal scale the fabric is not consistent. Broader, more gently sloping channels reveal consistent sediment fabric at the 10-m scale. In most cases, physical stratification decreases along the thalwegs of channels as water depths increase. In contrast, channel walls generally exhibit elevated impacts of bioturbation and variable amounts of physical stratification. Radiochemical profiles (210Pb, 137Cs) and the predominance of physical stratification (including discrete laminae with high sand content) suggest that the northern entrants are receiving more sediment than their southern counterparts. However, 210Pb profiles in this study demonstrate rapid accumulation of sediment everywhere in the head of Eel Canyon, with the highest rates of accumulation (> 40 mm/yr) found in the channel thalwegs. In thalwegs, evidence from sedimentary structures (e.g., erosional bases, cross-bedded sand layers) demonstrates that gravity flows occur frequently (many times each year) and have been linked by other investigations to storm impacts on the adjacent continental shelf. On decadal timescales, these processes are temporarily depositing sediment in the head of the canyon, which is removed over longer timescales—probably as larger gravity flows triggered by earthquakes. The radiochemical and sedimentological data collected at the base of entrant channels confirm that modern sediment is moving to deeper portions of the canyon.
An abuttable CCD imager for visible and X-ray focal plane arrays

A frame-transfer silicon charge-coupled-device (CCD) imager has been developed that can be closely abutted to other imagers on three sides of the imaging array. It is intended for use in multichip arrays. The device has 420*420 pixels in the imaging and frame-store regions and is constructed using a three-phase triple-polysilicon process. Particular emphasis has been placed on achieving low-noise charge detection for low-light-level imaging in the visible and maximum energy resolution for X-ray spectroscopic applications. Noise levels of 6 electrons at 1-MHz and less than 3 electrons at 100-kHz data rates have been achieved. Imagers have been fabricated on 1000- Omega cm material to maximize quantum efficiency and minimize split events in the soft X-ray regime. >
Increased β-secretase activity and expression in rats following transient cerebral ischemia

Abstract The aberrant proteolytic processing of the amyloid precursor protein (APP) by β- and γ-secretases is key to amyloid plaque formation in Alzheimer's disease (AD). Identification of an aspartyl protease as the β-secretase (β-site APP cleaving enzyme, BACE) involved in APP processing provides a pharmaceutical target for potential AD treatment. In the present studies, we demonstrate that transient cerebral ischemia in female rats caused a 30% increase in β-secretase activity. α-Secretase activity did not increase significantly. We examined protein levels of BACE1, and its analogue BACE2, in ischemic brain extracts. BACE1 protein levels increased 67%, while BACE2 protein level did not change after such a transient ischemia. Immunohistochemical studies demonstrated that BACE1 protein was increased in the ischemic neocortex, when compared with its contralateral cortex. Further, colocalization assessment indicated that BACE1 strongly associated with staining for the apoptotic marker, TUNEL. These results may partially explain epidemiological study, which demonstrate a higher incidence of dementia after stroke. Further, our results support the hypothesis that apoptosis and aberrant APP processing are correlated events in AD brain, and suggest that inhibition of BACE may have a therapeutic effect in the prevention of dementia after stroke recovery.
Effects of subchronic methamphetamine exposure on basal dopamine and stress-induced dopamine release in the nucleus accumbens shell of rats

Subchronic administration of stimulants reduces basal dopamine (DA) concentrations and blocks stress-induced DA release in the nucleus accumbens (NA) of rats during withdrawal. However, no studies have attempted to relate early withdrawal from chronic drug exposure to stress reactivity and changes in DA transmission. The effects of subchronic low-dose methamphetamine (METH) administration on regional changes in dopamine transporter (DAT) and norepinephrine transporter (NET) immunoreactivity and function during early withdrawal were examined. The effects of subchronic METH on stress responsivity measured by DA release in the nucleus accumbens shell (NA SHELL) and core (NA CORE) during acute restraint stress were also examined. Male rats received single injections of METH (2.0 mg/kg i.p.) or saline (SAL) for 10 days and then were killed 24 h after the last injection. DAT and NET protein in NA, striatum (STR), medial prefrontal cortex (mPFC), and hippocampus were assayed by Western blot analysis. Experiment 2 measured basal extracellular DA concentrations and restraint-stress-induced DA release in vivo in the NA SHELL and CORE of SAL- and METH-pretreated rats after 24-h withdrawal. Experiment 3 examined the in vivo regulation of extracellular DA in the NA SHELL and/or CORE after local administration of GBR12909 (50 μM) or nisoxetine (100 μM; NA SHELL). Subchronic METH increased DAT but not NET immunoreactivity in the NA compared to the STR and mPFC. METH reduced basal extracellular DA and blocked restraint-stress-induced DA release in the NA SHELL. DA uptake blockade increased extracellular DA more in the NA SHELL of METH rats, whereas NE uptake blockade increased basal DA concentrations to a similar extent in METH and SAL rats. These results suggest that subchronic METH exposure selectively increases NA DAT and consequently reduces basal and stress-induced DA release in the NA SHELL during early withdrawal.
Effective Yield Surfaces for Anisotropic Composite Materials

This work deals with the development of effective yield surfaces for two-phase composite materials made of homogeneous, isotropic, rigid/perfectly plastic constituents. For our purposes, a composite is a heterogeneous material with two distinct length scales: a macroscopic one, L ~ O(1), characterizing the overall dimensions of the specimen and the scale of variation of the applied loading conditions, and a microscopic one, l << L, characterizing the size of the typical heterogeneity (e.g., an inclusion). By effective properties, we mean the relation between the averages of the local stress and strain-rate fields within the composite. We consider the special class of microstructures consisting of aligned, self-similar, ellipsoidal inclusions distributed according to “ellipsoidal” two-point correlation functions in a matrix of another phase. Estimates of the Hashin-Shtrikman [6] type for the effective behaviour of linearly viscous (mathematically analogous to linear elastic) composites with this class of particulate microstructures were developed by Willis [14], [15]. They will be used here to generate corresponding estimates for the effective yield functions of the rigid/perfectly plastic composites by means of the variational procedure of Ponte Castaneda [7], [8].
Diagnostic reasoning in Nizāmī ‘Arūzī’s Four Discourses

Background Most studies on medical reasoning focus on contemporary allopathic practitioners. Here, the significance of diagnostic sense in Nizāmī ‘Arūzī’s Four Discourses ( Chahār Maqāle ), an influential text that circulated widely throughout the Islamic world, is explored. Methods After a brief introduction, key passages are translated on how doctors should cultivate analytical skills. Results Nizāmī ‘Arūzī cites three sources of diagnostic authority: (1) education in the texts of medical experts, (2) formal logic and (3) belief in the power of God. Conclusions ‘Arūzī’s methods, though rooted in a religious faith that may seem foreign to contemporary doctors and educators, has much to recommend regarding its clarity of approach, its high ethical standards and expectations of doctors, and its commitment to best practices for the patient. Crosscultural studies of medical education and professionalism can offer valuable insights by demonstrating how doctors across history and geography have grappled with the common concerns of diagnosis and treatment.
Growth hormone and insulin during oxandrolone therapy of stunting.

In a group of growth-retarded children, generally of the constitutional type with height below the tenth or the third percentile, the mean increases in serum growth hormone ohserved between the ½- and 2-hour points of an intravenous tolbutamide tolerance test were ab out the same as those recorded in a control group of normal children. Differences present in the 0 and 15 minute growth hormone values of the 2 groups were not outside the range recorded in control subjects. Also, the mean fasting and posttolbutamide levels of serum insulin, blood sugar, and serum inorganic phosphorus were of the same magnitude in the growth-retarded and the control groups. Administration of oxandrolone, a protein anabolie steroid with relatively low virilizing properties to growth-retarded children, at a dosage of 2.5 to 30 mg. per day for 3 months or longer, did not affect the fasting levels of serum insulin, serum inorganic phosphate, or blood sugar, nor the changes in these indices induced by tolbutamide. Growth hormone levels measured during the fasting state also remained unaltered during oxandrolone therapy. Infusion of tolbutamide or of arginine during oxandrolone treatment did not enhance growth hormone responses to these stimuli. Indeed, the peak growth hormone responses to tolbutamide and to arginine were lower during oxandrolone ingestion. In the arginine tests, the decrease in the peak growth hormone response was accompanied by lower peak levels of serum insulin.
Effect of Beta-Carotene and Cortisone on Vaginal Epithelium of Vitamin A Deficient Rats.∗

SummaryAbnormally cornified epithelium of the vagina induced by Vit. A deficiency disappeared when beta-carotene alone or beta-carotene and cortisone was administered. Cortisone alone did not modify the cornified epithelium of the vagina. The results demonstrate, therefore, that cortisone has no demonstrable effect on conversion of beta-carotene to Vit. A.
Electron Beam-Induced Reduction of TbO2−δ: A High Resolution Electron Microscope Study

Terbium forms a homologous series of oxides Tbn02n−2−2 where n is an integer between 4 (Tb406 = Tb203) and ∞ (Tb02). The structures of phases for n = 4, 7, 11, 12 and ∞ have been reported (1,2,3). In addition, and in common with Ce and Pr, Tb, a disordered fluorite α-phase is formed at higher temperatures and pressures, in the composition range Tb02−x, where 0 ≤ x ≤ 0.28. A study of α-Tb02−x the sequential stages of its reduction to form ordered intermediate phases has been carried out.
Evolutionary convergence and parallelism in crinoid calyx design

Eleven basic constructional designs are defined among the Crinoidea. Calyx designs are defined primarily by shape, geometry of plates at the base of the calyx, tegmen shape, fixed calyx plates, number of arms, and nature of radial facets. These calyx designs include the following: multiplated bowls, multiplated bicones, conical mosaics, urns, cylinders, cones, ellipsoids, hands, bowls, bilateral recumbents, and fists. Most crinoid subclasses and orders contain crinoids with several of these designs. This significant convergence and parallelism in calyx design indicates that the morphological evolution of crinoids has been substantially constrained by constructional and fabricational limitations.
75 IS CHRONIC HIGH-FREQUENCY GASTRIC ELECTRICAL STIMULATION EFFECTIVE IN PATIENTS WITH CHRONIC FUNCTIONAL NAUSEA AND VOMITING AND A NORMAL GASTRIC EMPTYING?

The aim of this study was to investigate the effectiveness of high-frequency gastric electrical stimulation (GES, Enterra Therapy) in patients with symptoms suggestive of gastroparesis but who had a normal gastric emptying and were given the diagnosis of functional nausea and vomiting. Methods This study included 11 such patients (3 M, 8 F, median age 41 years, range 21-53, 4 diabetic and 7 idiopathic) who had a documented normal baseline gastric emptying test (GET) (normal value at 4 hours 10% retention at 4 hours). Symptom severity of nausea, vomiting, and TSS were significantly improved. Sixty-four percent of patients had $ 50% reduction in TSS and the median reduction of TSS was 51%. Patients overall maintained their weight during the GES therapy. Conclusions In patients with functional nausea and vomiting and a normal GET high-frequency GES is effective in improving nausea, vomiting, and related symptoms as well as maintaining nutrition.
Prenatal care and pregnancy outcome

The relationship of prenatal care to perinatal outcome was studied in a racially and socioeconomically homogeneous population. All patients who were delivered at the E. H. Crump Women's Hospital and Perinatal Center from July 1 to December 31, 1979, were divided into two groups, based on the amount of prenatal care received. One group of 1,102 patients had 0 to 3 prenatal visits (average 1.43); the second group, consisting of 2,027 patients, had four or more visits (average 12.78). Both groups were similar with respect to age, marital status, previous obstetric history, and initial risk assessment. However, the group with inadequate prenatal care had significantly higher fetal, neonatal, and perinatal mortality rates.
Getting Too Personal

For both cults, the challenge posed by embodied living couldn’t be starker: persons, after all, are souls or ends, and thereby alone bear self-awareness, an enduring self-identity, and an agential capacity. In distinguishing us from other animals, these capacities simultaneously comprise for both views the central element of human worth. On both views, rejecting metaphysical dualism threatens the transcendence of animality that marks human worth. This case is made extensively by cult of life defenders Moreland and Rae, who argue that only such a dualistic understanding of human persons can serve as normative basis for bioethics.1 In the emotionally charged public debates surrounding not only euthanasia and PAS but also genetic engineering, cloning, human embryo research, and the like, the nature of personhood most often occupies center stage. This point is illustrated forcefully by the on-going furor over stem-cell research. Proponents deny that fetal tissue research involves human experimentation. Opponents, in contrast, affirm that life begins at conception, and that there is no other way to understand fetal tissue except as embodied humanity. This should be owed the full dignity appropriate to it, and experimentation upon these tissues is seen as putting some lives unconscionably at the service of others.
Outcomes of a Two-Component Intervention on Behavioral Symptoms in Persons With Dementia and Symptom Response in Their Caregivers

Purpose: This study evaluated the longitudinal influence of an individualized evidence-based psychoeducational intervention for caregivers on frequency of behavioral symptoms in persons with dementia (PWD) and caregiver reaction to these symptoms. The intervention included information about the disease process using Progressively Lowered Stress Threshold (PLST) content and a family meeting based on Mittelman’s New York University Intervention. Method: A quasi-experimental study design was implemented. The Revised Memory and Behavior Problems Checklist was administered to N = 127 caregiver/care recipient dyads at baseline, 6, 12, and 18 months follow-up. All caregivers were enrolled in the intervention at baseline and followed over 18 months. Linear mixed models were developed to evaluate effects on frequency of behavioral symptoms in PWD and caregiver response. Results: The most frequently occurring behavior was memory problems, although depressive behaviors produced the most negative caregiver responses....