cssi/SciSciGPT-SciSciNet huggingface dataset:
A reliable and efficient first principles‐based method for predicting pKa values. III. Adding explicit water molecules: Can the theoretical slope be reproduced and pKa values predicted more accurately?

A popular method for predicting pK(a) values for organic molecules in aqueous solution is to establish empirical linear least-squares fits between calculated deprotonation energies and known experimental pK(a) values. In virtually all such calculations, the empirically observed slope of the pK(a) vs. ΔE fit is significantly less than the theoretical value, 1/(2.303RT) (which is 0.73 mol/kcal at room temperature). In our own continuum solvation calculations (Zhang et al., J Phys Chem A 2010, 114, 432), the empirical slope for carboxylic acids was only 0.23 mol/kcal, despite the excellent fit to the experimental pK(a) values. There has been much speculation about the reason for this phenomenon. Although the ΔE - pK(a) relation neglects entropic effects, these are expected to largely cancel. The most likely cause for the strange behavior of the fitted slope is explicit solute-solvent (water) interactions, especially involving the ions, which cannot be described accurately by continuum solvation models. We used our previously developed pK(a) protocol (OLYP/6-311+G(d,p)//3-21G(d) with the COSMO solvation model) to investigate the effect of adding one or two explicit water molecules to the system. The slopes for organic acids (especially carboxylic acids) are much closer to the theoretical value when explicit water molecules are added to both the neutral molecule and the anion. However, explicit water molecules have almost no effect on the slopes for organic bases. Adding explicit water molecules to the ions only produces intermediate results. Unfortunately, linear fits involving explicit water molecules have much larger errors than with continuum solvation models alone and are also much more expensive. Consequently, they are not suitable for large-scale pK(a) calculations. The results compared with literature values showed that our predicted pK(a) s are more accurate.
On an approximation to the power function of the mantel haenszel test for relative risk

A normal approximation is developed for the power function of the mantel Haenszel (1959) test statistic for the hypothesis that the relative risk is unity in k 2 x 2 contingency tables. Certain numerical comparisons are made for k=2,3 with the exact power as computed by Bennett and Kaneshiro (1974)
Thermal conductivity of the solidified inert gases: Argon, neon and kryptont

Abstract The thermal conductivity of the solidified inert gases A, Ne and Kr, contained in an Inconel tube, has been measured at temperatures from 2°K to near their melting points. Above about 15°K, we find that the thermal conductivity, Δ may be represented by the expression Λ≃B/T, where B has values of 260 mw cm−1 for A, 75 for Ne, and 270 for Kr. Values calculated from approximate theoretical treatments of lattice anharmonicity yield values in excess of these by about 30% to 80%. At liquid helium temperatures, i.e. below the conductivity maximum, we find that Λ varies approximately as T 2 and is small in magnitude, suggesting mean free paths of 10−5 to 10−4 cm for the lattice waves. This may result from the large contraction of the solids during cooling which produces severe internal strains and probably results in many lattice defects within the crystals.
Screening for post-translational modifications in conotoxins using liquid chromatography/mass spectrometry: an important component of conotoxin discovery.

Abstract Mass spectrometry has emerged as an important technique for conotoxin analysis due to its capacity for selective, sensitive, information-rich analyses. Using liquid chromatography/mass spectrometry, Conus venom can be fractionated and the peptides surveyed for specific post-translational modifications, indicating those toxin components likely to have an important biological function. With Conus striatus and Conus victoriae venom as models, bromination, carboxylation and glycosylation modifications are identified through characteristics such as isotopic distribution and labile losses observed during mass spectrometric analysis. This modification screening approach enables the identification of a C. victoriae bromo-carboxy-conotoxin, designated vc5c, as a candidate for detailed mass spectrometric analysis. Using a cDNA sequence coupled with liquid chromatography/mass spectrometry and nanoelectrospray ionization-ion trap-mass spectrometry, the sequence of vc5c is determined to be ICCYPNXWCCD, where W is 6-bromotryptophan, X is γ-carboxy glutamate and C is disulfide-linked cysteine. This represents the ninth T-superfamily (–CC–CC– scaffold) toxin that has been isolated from venom and characterized.
Incorporation of Radiolabeled Whey Proteins into Casein Micelles by Heat Processing

Abstract Skim milk was heated at 70, 95, and 140°C to simulate the processes of pasteurization, forewarming, and UHT sterilization, and the specific interactions between α-lactalbumin or β-lactoglobulin and the caseins studied using tracer amounts of added 14 C-labeled whey protein. Radioactivities of the whey and of the washed casein pellets from renneted skim milk were measured and the extent of the interaction estimated. Upon heating skim milk at 70°C for 45s, less than 2% β-lactoglobulin and less than .3% α-lactalbumin were incorporated into the curd. Heating at 95°C for .5 to 20min resulted in 58 to 85% of the β-lactoglobulin and 8 to 55% of the α-lactalbumin becoming associated with the curd. Heating at 140°C for 2 and 4s caused 43 and 54% of the β-lactoglobulin and 9 and 12% of the α-lactalbumin, respectively, to be bound to the curd fraction. The radiolabeling technique is very sensitive and useful for tracing low levels of interaction between whey proteins and casein in heated milk systems.
Landscape change with agricultural intensification in a rural watershed, southwestern Ohio, U.S.A.

Specialized cash grain production, emergent in the midwestern United States during the post-WWII era, typifies the Upper Four Mile Creek watershed in southwestern Ohio. This style of agriculture intensifies cropland use, with consequent increases in soil erosion and stream sedimentation - a serious problem in the lower reservoir, Acton Lake. Agricultural statistics and aerial photographs compiled between 1934 and 1984 were used to quantify agricultural dynamics and landscape change in the watershed, including land-use apportionment, diversity, and the structural configuration of forest, woodland, and old-field/brushland patches and corridors. A questionnaire sent to all land owners in the basin documented farm-level characteristics and factors that influence management decisions. Crop diversity (H′) in Preble County, Ohio decreased from 1.42 in 1934 to 1.17 in 1982, as corn and soybeans dominated the landscape mosaic. Yields rose, but net profits were reduced by declining prices per bushel and increases in fertilizer and petroleum-based subsidies. Landuse diversity in the county also declined (H′ = 1.37 in 1934 tot 0.80 in 1982) in response to cropland expansion, whereas forest land in the watershed increased from 1605 to 2603 ha. Fragmentation declined and the landscape became polarized after 1956, with a concentration of agricultural patches in the upper watershed and forest-patch coalescence in stream gullies and state park land in the lower watershed. The questionnaire (~ 29% return) further supported, at the farm-level, observed regional trends toward expansion (farm coalescence and lease contracts) and specialization (conversion toward corn and soybeans). The most important factors influencing farm size and management were better equipment and family traditions. Thus, cultural and technological factors that operate at the farm-level, coupled with meso-scale variation in the physical conditions of a catchment basin, tend to influence landscape-level patterns more than regional socioeconomics and governmental policies.
SUPRALINEARITY OF NUCLEAR RESEARCH EMULSIONS

Abstract Nuclear emulsions processed in discriminating developers, intended to suppress small latent image sites, exhibit supralinear sensitometric blackness-exposure curves, whose character varies according to developing time, concentration, and composition, yielding hittedness ranging from 1 to 8, singly and in combination. These emulsion-processing combinations display the phenomena called ion-kill (sensitization by the transit of a single charged particle) and gamma- kill (sensitization by the overlap of secondary electron paths, whether from x-rays or from the delta-rays of heavy ions) in radiobiology. Here emulsions are blackened by x-rays when these same plates reveal no electron tracks, or no alpha-particle tracks, or even no fission fragment tracks. The supralinearity of the emulsion response to x-rays, and the consequent suppression of low LET radiations suggest that these materials have the potential to mimic the response of biological systems to particulate radiations of different charge and s...
CALCIUM TRANSPORT IN TOMATO ROOTS.

THE absorption of calcium by plant tissue generally has been considered to be a process involving metabolic uptake. Fried et al.1, using excised barley roots, and Chasson and Levitt2, using potato slices, found a rapid initial uptake of calcium-45 followed by a slower linear increase with time. The linear phase was interpreted to represent metabolic absorption of calcium at a constant rate. However, Moore et al.3, in experiments with excised barley roots, found that when the uptake of inert calcium was determined by chemical analysis, the linear phase increased only slightly with time. When the uptake of calcium-45 was measured, the increase in the linear phase was much more pronounced, presumably because of exchange of radioactive calcium for inert calcium present in the root tissues. In addition, calcium uptake was not reduced by low temperature or treatment with dinitrophenol. Consequently, Moore et al. concluded that in barley roots, calcium uptake was largely non-metabolic in the physiological pH range. Handley and Overstreet4 have reported that calcium uptake in primary roots of maize is non-metabolic in the meristematic portions of the root tip, but is largely metabolic in the older vacuolated portions of the root. In a recent examination of calcium accumulation in barley seedlings, Barber and Koontz5 concluded that metabolism was involved in the process by which calcium was eventually accumulated by the barley shoot.
The home inventory of dangers and safety precautions-2: addressing critical needs for prescriptive assessment devices in child maltreatment and in healthcare

Abstract Objective: This paper describes the development and preliminary validation of a prescriptive home danger and safety precaution instrument containing 14 epidemiological categories to be used in the design and evaluation of family-tailored injury prevention and safety interventions. Method: The HIDSP-2 evolved from application and revision of the previous home danger and safety precaution recognition and observation instruments. As part of this process, the suitability of the HIDSP-2 for use in a broad-based trial was evaluated with 29 low income parents exhibiting individual learning needs. Inter-rater reliability and stability of scores were examined. Internal consistency was examined for total dangers and precautions and for those categories in which there were sufficient items to do so. Results: Administrative time was reduced while continuing usefulness in the identification and remediation of dangers and implementation of precautions was demonstrated. Stability of observation was high. Alphas as a measure of internal consistency was satisfactory for total danger and precautions separately; however, those for most individual categories were low. There was significant reduction in the number of dangers identified initially and significant improvement in the safety precautions implemented. Conclusions: The HIDSP-2 can assist healthcare, education, disability, and child protective service workers in the development of home safety plans for remediating home dangers and implementing precautions. While we see this instrument as eminently suitable for use in broad-based interventions and in epidemiological studies, further research must continue to examine the psychometric characteristics of the individual danger and precaution categories.
HLA-B27 Transgenic Rats Are Susceptible to Accelerated Alveolar Bone Loss

Background: HLA-B27 transgenic rats exhibit generalized, severe inflammatory reactions and spontaneously develop arthritis and chronic gastrointestinal inflammation, as well as inflammatory lesions in other tissues. Our hypothesis was that HLA-B27 rats would also be susceptible to inflammatory periodontal disease, and therefore alveolar bone loss. The purpose of this investigation was to compare the naturally occurring alveolar bone loss in HLA-B27 and wild type rats. Methods: Age- and sex-matched HLA-B27 transgenic (TG) and wild type Fischer 344 (WT) female retired breeders, and their age-matched male WT breeding mates, were examined for alveolar bone loss (ABL). Thirty-eight animals were used: twelve, 20, and 6 animals were 6, 8, and 12 months old, respectively. ABL was measured as the exposed root surface area (mm2) in the defleshed maxilla and mandible. Results: The coefficient of variation for replicate ABL measurements was 4.4%. For the 6- and 8-month age groups, ABL was significantly greater in TG ...
Fever, irritability, and ulcerations in an infant.

: A young infant with fever and oral ulcerations is presented herein. Extensive infectious, nutritional, immunodeficiency and autoimmune work up was performed. Pertinent maternal history suggested the potential diagnosis of neonatal Behcet’s, and treatment for this condition resulted in rapid and sustained clinical improvement.
Implementation of the optical atom probe

Abstract A serial version of a three-dimensional atom probe has been constructed. The main components of the optical atom probe (OAP) are a Galileo Electro-optics FIM70 detector, a fiberoptics reducing taper, an ITT4111 image intensifier tube, an EG&G reticon MC9256 CCD camera, a Data Design Corporation AC100 CAMAC module and a LeCroy 4208 time-to-digital converter. The instrument may be used in several modes such as a field-ion microscope, a computerized field evaporation microscope, a wide angle atom probe, and a three-dimensional atom probe.
U.S. security policy in a nuclear‐armed world or: What if Iraq had had nuclear weapons?

(1997). U.S. security policy in a nuclear‐armed world or: What if Iraq had had nuclear weapons? Security Studies: Vol. 6, No. 3, pp. 1-31.
Impacts of shortwave radiation forcing on ENSO: a study with a coupled tropical ocean-atmosphere model

We describe a coupled tropical ocean-atmosphere model that represents a new class of models that fill the gap between anomaly coupled models and fully coupled general circulation models. Both the atmosphere and ocean are described by two and half layer primitive equation models, which emphasize the physical processes in the oceanic mixed layer and atmospheric boundary layer. Ocean and atmosphere are coupled through both momentum and heat flux exchanges without explicit flux correction. The coupled model, driven by solar radiation, reproduces a realistic annual cycle and El Nino-Southern Oscillation (ENSO). In the presence of annual mean shortwave radiation forcing, the model exhibits an intrinsic mode of ENSO. The oscillation period depends on the mean forcing that determines the coupled mean state. A perpetual April (October) mean forcing prolongs (shortens) the oscillation period through weakening (enhancing) the mean upwelling and mean vertical temperature gradients. The annual cycle of the solar forcing is shown to have fundamental impacts on the behavior of ENSO cycles through establishing a coupled annual cycle that interacts with the ENSO mode. Due to the annual cycle solar forcing, the single spectral peak of the intrinsic ENSO mode becomes a double peak with a quasi-biennial and a low-frequency (4–5 years) component; the evolution of ENSO becomes phase-locked to the annual cycle; and the amplitude and frequency of ENSO become variable on an interdecadal time scale due to interactions of the mean state and the two ENSO components. The western Pacific monsoon (the annual shortwave radiation forcing in the western Pacific) is primarily responsible for the generation of the two ENSO components. The annual march of the eastern Pacific ITCZ tends to lock ENSO phases to the annual cycle. The model's deficiencies, limitations, and future work are also discussed.
Making destiny manifest: United States territorial expansion and the dispossession of two Mexican property claims in New Mexico, 1824–1899

Abstract In the aftermath of the war of expansion against Mexico, the United States undertook a lengthy adjudication process of Spanish and Mexican property claims throughout the newly acquired territory. In New Mexico, nearly all Spanish and Mexican community land grants were either rejected by U.S. courts or were acquired by commercial interests during a period of intense land speculation. In addition to legal explanations of dispossession, most historical land grant research has emphasized the role of commercial speculators in the dispossession of land grants. The Santa Fe Ring, a loose affiliation of lawyers, politicians, federal and territorial officials and commercial investors, became a potent political and economic force in New Mexico during the 19th century. This article explores the adjudication and speculation histories of two Mexican property claims: the Petaca and Town of Vallecito de Lovato. The dearth of historical knowledge of the practices and tactics of land dispossession in specific New Mexico land grants continues to obscure the full story of U.S. territorial expansion and the history of the transformation in property relations. This article sheds new light on the extent and intensity of commercial speculation and the contribution of those efforts to undermine legitimate claims.
The Application of the Fermi-Thomas Statistical Model to the Calculation of Potential Distribution in Positive Ions

The statistical method of Fermi and Thomas of calculating atomic potential distributions has been extended to include positive ions. A table of potentials for any positive ion is given. The results have been applied to the calculation of (a) ionic radii, (b) successive ionization potentials, (c) deviations from the Mosely law in optical spectra.
Absorption-promoting adjuvants: enhancing action on rectal absorption

Abstract Studies of absorption-promoting adjuvants used for the modification of the barrier function of the rectal membrane are interesting for biochemical research as well as providing a basis for the development of new formulations of poorly absorbed drugs such as some moderately large water soluble drugs and peptides. Compounds such as chelating agents and sulfhydryl depleters increase the rectal absorption of drugs through the paracellular route and transcellular route, respectively, by modifying the barrier function of each route. Salicylate, its derivatives and fatty acids also increase rectal drug absorption through both routes. Lectin increases rectal absorption of drugs by inducing microvillous infusion. With respect to formulation development, ampicillin suppositories incorporating sodium caprylate as an absorption promoting adjuvant were confirmed clinically to be an effective formulation, and are a marketed product in Japan. In human trials, administration of insulin in a combination with salicylate inhibited postprandial hyperglycemia in diabetic patients.
Minimally Invasive Heart Valve Surgery: How and Why in 2012

Cardiac surgical procedures via traditional sternotomy are safe and effective operations performed by cardiothoracic surgeons worldwide. However, postoperative limitations in upper extremity activity during bone healing are seen as undesirable by some. Percutaneous catheter-based attempts to emulate the outcomes of traditional cardiac surgical procedures have largely fallen short of established standards of efficacy and durability. The field of minimally invasive heart valve surgery thus developed out of a need to offer smaller, better-tolerated incisions to patients while maintaining high-quality clinical outcomes. These operations are safe and effective when performed by proficient surgical teams, allowing patients to resume normal activities more rapidly. We explore current evidence supporting the practice of minimally invasive heart valve surgery in 2012 and analyze the clinical impact of these nascent surgical platforms.
Transport of Benzene and Trichloroethylene Through a Landfill Soil Liner Mixed With Coal Slurry

Abstract The effect of mixing three Kentucky, U.S.A. coal slurries with soil on the transport of benzene and trichloroethylene (TCE) through a compacted landfill soil liner was investigated. Using typical values for variables, assuming no competition between contaminants, and a two to one soil-coal slurry ratio all three coal slurries were predicted to maintain the concentration of benzene emanating from a landfill liner below the maximum concentration limit (MCL) of 0.005 mg/l for at least 40 years. The concentration of TCE emanating from a landfill liner was predicted to remain below 0.001 mg/l for at least 100 years. The saturated hydraulic conductivity of a compacted silty loam soil (typical landfill soil liner material) was not found to be affected by the addition of coal slurry at a ratio of two parts soil to one part coal slurry. The results presented indicate that coal slurry amended soil will slow the movement of non-ionic organic contaminants through a landfill liner while the liner retains a low hydraulic conductivity.
Assessment of polar climate change using satellite technology

Using results of selected studies, this paper highlights some of the problems that exist in the remote sensing of snow and ice, and demonstrates the importance of remote sensing for the study of snow and ice in determining the effect of temperature increase, due to the atmospheric CO2 increase, on the cryospheric features. Evidence obtained from NOAA, Nimbus, and other satellites, that may already indicate a global or at least a regional warming, includes an increase in permafrost temperature in northern Alaska and the retreat of many of the world's small glaciers in the last 100 years. It is emphasized that remote sensing is of major importance as the method of obtaining data for monitoring future changes in cryospheric features.
Degradation of Carbon-14-Atrazine and Carbon-14-Metolachlor in Soil from Four Depths

Degradation of 14 C-atrazine [2-chloro-4-ethylamino-6-isopropylamino-s-triazine] and 14 C-metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide] was monitored for 6 and 2 mo, respectively, using sterile and nonsterile soil microcosms. Both chemical and biological degradation were observed for atrazine, metolachlor degraded only biologically. The calculated half-life of atrazine was 3.6 wk in nonsterile surface samples (0-5 cm). At the surface, after 22 wk, bound residues accounted for almost 60% of the recovered radioactivity while 36% was recovered as 14 CO 2 , indicating significant cleavage of the triazine ring. For sterilized surface samples, atrazine degraded chemically with bound residues accounting for 63% of the recovered label and had a calculated half-life of 6.2 wk. Degradation and binding were somewhat lower in soil samples from 20 to 25 cm and deeper subsurface samples (45 and 75 cm) showed almost no degradation and very little binding. Metolachlor degraded only in the surface nonsterile samples; no degradation was observed in subsurface samples or in sterile samples from any depth. Bound residues occurred in high amounts in the surface soil (31%) but declined rapidly with depth, indicating that organic matter is the primary binding site for metolachlor. Very little 14 CO 2 (<1.6%) was produced from metolachlor in any sample. This study showed that both herbicides degraded slower and sorbed less to the soil with increasing soil depth, especially below 25 em. Quantifying degradation rates of agricultural chemicals in the vadose zone is important for predicting and preventing groundwater contamination as well as for successful implementation of in-situ bioremediation of contaminated subsoils.
Inhibition of chloride secretion by furosemide in canine tracheal epithelium.

Furosemide inhibits Cl transport in a variety of epithelial and nonepithelial cells. To examine the mechanism of Cl secretion in canine tracheal epithelium, the effect of furosemide on transepithelial ion fluxes, membrane resistances, and electromotive forces was determined using intracellular microelectrodes and an equivalent electrical circuit analysis. There were six main observations: First, furosemide was only effective when added to the submucosal solution. Second, inhibition by furosemide (10−3 m) was specific for Cl secretion with no effect on Na absorption. Third, furosemide produced a half-maximal inhibition of Cl secretion at a concentration of 7×10−6 m. A Hill plot yielded a slope not different from unity, suggesting a one-for-one interaction of furosemide with the Cl transport process. Fourth, despite complete inhibition of Cl secretion, furosemide produced only small changes in transepithelial and apical membrane resistance, indicating that the primary effect was not an inhibition of Cl exit from the cell across the apical membrane. Fifth, basolateral membrane resistance and electromotive force were not altered by furosemide. This finding suggested that the effect of furosemide at the basolateral membrane was on an electrically neutral Cl entry process. Sixth, calculation of the intracellular Cl concentration from the electromotive force across the apical membrane indicated that furosemide decreased intracellular Cl concentration by 50%, consistent with an inhibition of Cl entry into the cell. These results indicate that Cl enters the epithelial cell via an electrically neutral process at the basolateral membrane and that furosemide selectively inhibits that process, resulting in a decreased intracellular Cl concentration and a decrease in the driving force for Cl exit across the apical membrane.
Regulation of eosinophil membrane depolarization during NADPH oxidase activation

Protein kinase C (PKC) activation in human eosinophils increases NADPH oxidase activity, which is associated with plasma membrane depolarization. In this study, membrane potential measurements of eosinophils stimulated with phorbol ester (phorbol 12-myristate 13-acetate; PMA) were made using a cell-permeable oxonol membrane potential indicator, diBAC4(3). Within 10 minutes after PMA stimulation, eosinophils depolarized from– 32.9±5.7 mV to +17.3±1.8 mV. The time courses of depolarization and proton channel activation were virtually identical. Blocking the proton conductance with 250 μM ZnCl2 (+43.0±4.2 mV) or increasing the proton channel activation threshold by reducing the extracellular pH to 6.5 (+44.4±1.4 mV) increased depolarization compared with PMA alone. Additionally, the protein kinase C (PKC) δ-selective blocker, rottlerin, inhibited PMA-stimulated depolarization, indicating that PKCδ was involved in regulating depolarization associated with eosinophil NADPH oxidase activity. Thus, the membrane depolarization that is associated with NADPH oxidase activation in eosinophils is sufficient to produce marked proton channel activation under physiological conditions.
Polysaccharide hydrogels for protein drug delivery

Abstract Delivery of protein drugs is highly challenging due to the low permeability, short circulatory half-life, rapid proteolysis, low stability, and immunogenicity of the protein drugs. Studies using polysaccharide hydrogels to overcome these problems are reviewed. The different approaches are divided into four classes: (1) polysaccharide microspheres; (2) polysaccharide-conjugated protein drugs; (3) polysaccharide matrix in protein drug delivery; and (4) microencapsulation of protein drugs. Polysaccharide hydrogels will be useful in the development of controlled release formulations for protein drugs.
A CRACK-TIP-ZONE INTERACTION MODEL FOR CREEP-FATIGUE CRACK GROWTH

— A crack-tip-zone interaction model for creep-fatigue crack growth is proposed. The basic details of the model are described. Experimental evidence in support of this model is presented. Existing data on creep-fatigue crack growth interaction agree qualitatively with the model. Some quantitative evidence for the model is presented and more is being developed in current work.
Mending the Failing Heart with a Vascularized Cardiac Patch

Functional, stem-cell-containing cardiac grafts will require vascularized myocardial constructs to support their survival and integration into the host vasculature. Recently in Tissue Engineering, Part A, Lesman et al. (2009) reported the successful integration of vascular cells and hESC-derived cardiomyoctyes into stable grafts in rat recipients.
Matrix deposition of tryptophan-containing allelic variants of type IX collagen in developing human cartilage

Abstract Genetic polymorphisms that encode a tryptophan (Trp) residue in the triple-helical domain of the α2 (Trp2) or α3 chain (Trp3) of human type IX collagen have been linked to risk of degenerative intervertebral disc disease. To determine whether these two allelic variants express protein that may affect the extracellular matrix of cartilage in vivo, we examined the properties of resident type IX collagen in an anonymous collection of embryonic and fetal human cartilage samples screened for Trp genotypes. No difference was found in the yield and electrophoretic properties of pepsin-solubilized type IX collagen between Trp2, Trp3 and non-Trp cartilage samples. On Western blot analysis, a polyclonal antiserum raised against a synthetic peptide matching the immediate Trp-containing sequence of the Trp3 allele reacted specifically with the α3(IX) chain prepared from Trp3 cartilage samples. Two-dimensional peptide mapping of type IX collagen in CNBr-digests of whole tissue gave indistinguishable fingerprints for Trp2, Trp3 and control tissues, including the yield of cross-linked peptides. Analysis of one cartilage sample that was homozygous for the Trp2 allele also gave a normal yield of collagen IX, including its α2 chain and a normal profile of cross-linked peptides. Together, the findings indicate that both Trp2 and Trp3 allelic products are incorporated into the cross-linked fibrillar network of developing human cartilage apparently normally. Any pathological consequences are likely, therefore, to be long-term and indirect rather than from overt misassembly of matrix.
Methylphenidate impairs learning and memory in normal adults

The effects of three doses of methylphenidate (0.1, 0.25, and 0.5 mg/kg, iv) on learning and memory were assessed in normal adults. When learning was scheduled 15 min after drug infusion, the high dose impaired learning and retention on two of the three tasks. The lower doses had no effect. When the drug was infused immediately after learning, retention was normal 24 hr later for all doses and tasks. It is suggested that methylphenidate's effect on performance may be due to a disruption of attention during learning, rather than to a specific effect on memory storage processes. Whereas facilitatory effects of some stimulant drugs on performance in memory tasks have been reported, it is proposed that facilitatory effects will be difficult to obtain in normal health adults.
Behavioural effects of mercury on grass shrimp

Abstract Subacute exposure (0.05 ppm) to mercuric chloride significantly impairs the conditioned avoidance responses of grass shrimp Palaemonetes pugio Holthuis, when tested in an aquatic avoidance apparatus. Control animals learn to avoid a shock after the onset of a light which followed a period of dark-adaptation. A third group of shrimp, which establish an avoidance curve similar to the controls, quickly lose its ability to avoid being shocked when exposed to mercury in the final days of the experiment. These experiments demonstrate the value of a simple behavioural index for establishing subacute toxicity standards for organisms in aquatic ecocystems.
A portable software tool for computing digitally reconstructed radiographs

Purpose : To develop a portable software tool for fast computation of digitally reconstructed radiographs (DRR) with a friendly user interface and versatile image format and display options. To provide a means for interfacing with commercial and custom three-dimensional (3D) treatment planning systems. To make the tool freely available to the Radiation Oncology community. Methods and Materials : A computer program for computing DRRs was enhanced with new features and rewritten to increase computational efficiency. A graphical user interface was added to improve ease of data input and DRR display. Installer, programmer, and user manuals were written, and installation test data sets were developed. The code conforms to the specifications of the Cooperative Working Group (CWG) of the National Cancer Institute (NCI) Contract on Radiotherapy Treatment Planning Tools. Results : The interface allows the user to select DRR input data and image formats primarily by point-andclick mouse operations. Digitally reconstructed radiograph formats are predefined by configuration files that specify 19 calculation parameters. Enhancements include improved contrast resolution for visualizing surgical clips, an extended source model to simulate the penumbra region in a computed port film, and the ability to easily modify the CT numbers of objects contoured on the planning computed tomography (CT) scans. Conclusions : The DRR tool can be used with 3D planning systems that lack this functionality, or perhaps improve the quality and functionality of existing DRR software. The tool can be interfaced to 3D planning systems that run on most modern graphics workstations, and can also function as a stand-alone program.
Seedling competition between native Populus deltoides (Salicaceae) and exotic Tamarix ramosissima (Tamaricaceae) across water regimes and substrate types

Populus deltoides subsp. wislizinii (Salicaceae), a cottonwood native to the Middle Rio Grande of New Mexico, must potentially compete against exotic Tamarix ramosissima (Tamaricaceae) during establishment after flooding. We investigated competitive interactions between seedlings of Tamarix and Populus in two substrates representing field textures and declining (i.e., draw-down) or stagnant water tables. The experiment was performed using a full-additive series design and interpreted with response surface models for each species. As reflected in both aboveground mass and height, Populus suppressed aboveground growth of Tamarix across all treatments, whereas competitive effects of Tamarix against Populus could only be seen at low Populus densities. Clay substrates with draw-down stimulated the greatest growth and created the most intense competitive environment for both species. Tamarix was competitively suppressed in every substrate tested, with the weakest response in sand with no draw-down, where growth of Populus was poorest. These results suggest that stream flow management that promotes Populus establishment could also aid in controlling Tamarix invasion across a range of substrates.
Beobachtungen an den seltenen Erden. XXXVIII. Elektrolytische Herstellung der Amalgame der seltenen Erden II. Zersetzung des Lanthanamalgams zur Gewinnung des freien Metalls

Es wird eine Methode beschrieben, welche die elektrolytische Herstellung des Lanthanamalgams erlaubt.
OPTIMAL, EFFICIENT RECONSTRUCTION OF PHYLOGENETIC NETWORKS WITH CONSTRAINED RECOMBINATION

A phylogenetic network is a generalization of a phylogenetic tree, allowing structural properties that are not tree-like. In a seminal paper, Wang et al.(1) studied the problem of constructing a phylogenetic network, allowing recombination between sequences, with the constraint that the resulting cycles must be disjoint. We call such a phylogenetic network a "galled-tree". They gave a polynomial-time algorithm that was intended to determine whether or not a set of sequences could be generated on galled-tree. Unfortunately, the algorithm by Wang et al.(1) is incomplete and does not constitute a necessary test for the existence of a galled-tree for the data. In this paper, we completely solve the problem. Moreover, we prove that if there is a galled-tree, then the one produced by our algorithm minimizes the number of recombinations over all phylogenetic networks for the data, even allowing multiple-crossover recombinations. We also prove that when there is a galled-tree for the data, the galled-tree minimizing the number of recombinations is "essentially unique". We also note two additional results: first, any set of sequences that can be derived on a galled tree can be derived on a true tree (without recombination cycles), where at most one back mutation per site is allowed; second, the site compatibility problem (which is NP-hard in general) can be solved in polynomial time for any set of sequences that can be derived on a galled tree. Perhaps more important than the specific results about galled-trees, we introduce an approach that can be used to study recombination in general phylogenetic networks. This paper greatly extends the conference version that appears in an earlier work.(8) PowerPoint slides of the conference talk can be found at our website.(7).
Defect structure in single crystal titanium carbide

The defects and crystallinity of as-grown and annealed TiC x (grown by the high-pressure float-zone) were examined by TEM and double crystal x-ray rocking curves. Three types of subboundaries and planar defects within subgrains were observed in as-grown TiC x . Subboundaries are classified by structure as (i) wide-extended, fault-like defects (WEFLD's), (ii) edge dislocation arrays, and (iii) dislocation networks. Planar defects were observed at dislocation nodes of subboundaries and also within subgrains; this is the first reported observation of planar defects within TiC x subgrains. The misorientation and/or density of subgrains in TiC x was reduced significantly by annealing at 2300 °C in contact with graphite.
Spatial cognition, mobility, and reproductive success in northwestern Namibia

Abstract Males occupy a larger range than females in many mammal populations including humans, and show an advantage in certain spatial-cognitive laboratory tasks. Evolutionary psychologists have explained these patterns by arguing that an increase in spatial ability facilitated navigation, which allowed range expansion in pursuit of additional mating and hunting opportunities. This study evaluates this hypothesis in a population with navigational demands similar to those that faced many of our ancestors, the Twe and Tjimba of northwestern Namibia. Twe and Tjimba men have larger visiting ranges than women and are more accurate in both spatial (mental rotations) and navigational (accuracy pointing to distant locations) tasks. Men who perform better on the spatial task not only travel farther than other men, but also have children with more women. These findings offer strong support for the relationship between sex differences in spatial ability and ranging behavior, and identify male mating competition as a possible selective pressure shaping this pattern.
Reliability comparison of two metallurgies for ceramic ball grid array

Surface-mountable ceramic ball grid array (CBGA) packages have proven to be attractive in a variety of applications as designers seek to maximize electrical performance, reduce card real estate, and improve manufacturing process yields. In support of the PowerPC family of microprocessors, 21 mm CBGA packages (256 leads) were used to evaluate two different ball metallurgies-90/10 Pb/Sn and 62/36/2 Sn/Pb/Ag. Test modules were assembled to printed circuit cards and cycled at 0 to 100/spl deg/C and -40 to 125/spl deg/C to evaluate the relative fatigue behavior of the interconnections. Ball attach techniques and module-to-card assembly processes are described, including screening, placement, and reflow. Failure mechanisms and fatigue reliability are discussed for both metallurgies. >
Air Medical Evacuations of Soldiers for Oral-Facial Disease and Injuries, 2005, Operations Enduring Freedom/Iraqi Freedom

This retrospective study was conducted to assess the nature and causes of serious oral-facial illnesses and injuries among U.S. Army personnel deployed to Iraq and Afghanistan in 2003 and 2004. Information for this study came from the U.S. Air Force Transportation Regulating and Command & Control Evacuation System database for medical evacuations (MEDEVACS) for 2003 to 2004. The study found 327 oral-facial MEDEVACS out of Iraq (cumulative incidence: 11/10,000 soldiers per year) and 47 out of Afghanistan (cumulative incidence: 21/10,000 soldiers per year), for a total of 374 MEDEVACS. Forty-two percent (n = 158) of all oral-facial MEDEVACS were due to diseases of the oral cavity, salivary glands, and jaw. Another 36% (n = 136) of oral-facial MEDEVACS were for battle injuries, primarily fractures of the mandible, caused by acts of war. Twenty-one percent (n = 80) of oral-facial MEDEVACS were due to nonbattle injuries, primarily fractures of the mandible, mainly caused by motor vehicle accidents and fighting.
Seasonal Changes in Scents and Responses to them in Meadow Voles: Evidence for the Co-evolution of Signals and Response Mechanisms

Relatively little is known about the mechanisms of communication during the non-breeding season in species that are seasonal breeders. Previous work with meadow voles, Microtus pennsylvanicus, housed under long photoperiods, has shown that they prefer the odors of opposite-sex conspecifics. In this paper, we investigated the effects of short photoperiod on preferences for sex-specific odors and the production of such odors. Short-photoperiod females preferred anogenital and fecal scents of other short-photoperiod females over those of males, but did not show sexual preferences for three other scents. Short-photoperiod males did not exhibit sexual preferences for any of the odors. Furthermore, scents from short-photoperiod voles did not elicit sex-specific preferences in long-photoperiod voles, and scents from long-photoperiod voles did not elicit preferences from short-photoperiod voles. These and previous results indicate that both the odors and responses to odors change seasonally and that long-photoperiod voles respond selectively to scents from long-photoperiod voles and short-photoperiod voles respond selectively to scents from short-photoperiod voles. Taken together, these results suggest the co-evolution of seasonal changes in scents and in perceptual or other response mechanisms.
Bypassing the Limitations of Classical Chemical Purification with DNA‐Programmable Nanoparticle Recrystallization

Crystallization is a common and invaluable tool in chemistry for obtaining compounds with a high degree of purity. In a mixture of two or more species, conditions are found in which the desired component is able to selectively form a crystalline structure that excludes impurity species which are unable to incorporate into the ordered lattice formed by the product. This process has been used to purify myriad organic molecules, resolve racemic mixtures with chiral additives, and even separate complex protein mixtures to arrive at samples of maximum homogeneity. Without such tools to obtain materials that are uniform in their structure, function, and composition, elucidation of their chemical and physical properties would be extremely challenging and, in some cases, impossible. Interestingly, a host of anisotropic nanoparticle syntheses currently suffer from an analogous problem as the aforementioned molecular systems—the presence of impurity nanostructures with disparate shapes that obviate a variety of measurements, confound data analysis, and preclude potential applications. Surprisingly few separation methods exist for addressing this challenge and it has been shown that conventional methods for crystallizing nanoparticles based on drying effects or capillary forces are not effective at separating differently shaped nanoparticles. However, recent work from our group has demonstrated that anisotropic nanostructures functionalized with a dense shell of oligonucleotides are capable of hybridizing one another and forming ordered superlattices with a binding constant six orders of magnitude larger than comparable spherical nanoparticle conjugates. In addition, the programmability inherent to DNA in both sequence and length allows the interactions between nanoparticles to be tailored to optimize their assembly into crystalline superlattices. Herein we show that DNA-programmable nanoparticle crystallization is capable of maximizing the thermodynamic selectivity for one particle shape to form an ordered phase in preference to another. This is in stark contrast to classical chemical crystallization in which the molecular interactions that dictate crystal formation are predetermined by the species being purified and are essentially unalterable. The preferential formation of ordered superlattices that exclude impurity nanoparticles of undesired shapes allows the crystallized nanoparticle product to be separated, resulting in samples of substantially increased homogeneity (Scheme 1). Finally, we show the first experimental derivation of molar extinction coefficients for these materials, as determination of this property requires a degree of sample purity which has been previously unobtainable.
Investigation into packet delivery options for WLAN access points implementing unscheduled power save delivery

In this paper we propose and evaluate the performance of techniques for controlling the delivery of traffic to WLAN stations in power save mode. The options evaluated include using unscheduled automatic power save delivery for delay sensitive traffic while requiring stations to poll for traffic from delay tolerant applications, versus using unscheduled power save delivery for both types of traffic in cases where a station has multiple sessions running. Particular attention is paid to practical issues related to signaling when the power save buffers of an access point are temporarily empty, and the interplay of different delivery and implementation options supporting quality of service (QoS)
Algorithm Advancements for the Measurement of Single Cell Oxygen Consumption Rates

Advancements in methods and algorithms for the measurement of oxygen consumption rates of single cells is presented. In this system a low density of randomly seeded eukaryotic cells are sealed in an array of microwells etched in glass (zero to three cells per microwell). The decrease in oxygen concentration inside each microwell in the array is measured yielding the oxygen consumption rates of the cells trapped in the array. While fundamentally simple in concept, the system requires advanced algorithms for data collection and image processing. The data collection technique enabling the oxygen sensors in each microwell has been modified to increase speed and sensor precision. Utilizing internal triggering and an integrate-on-chip mode rather than external triggering and an off-chip accumulation mode improves sensor precision by 45% and increases collection speed by a factor of seven. Furthermore, an optimized sensor locator algorithm has reduced the time to process image data for a single oxygen measurement point five-fold. A new measurement technique involving custom image-processing algorithms has also been developed revealing the microwell volumes to be 0.54 nL on average with a 6% maximum spread from the mean. To demonstrate the utility of the system, we present an experiment that successfully measured the oxygen consumption rates of 1, 2 or 3 cells in nine individual microwells simultaneously.