cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of vegetation type on mercury concentrations and pools in two adjacent coniferous and deciduous forests

Vegetation type and ecosystem structure affect major aspects of the mercury (Hg) cycle in terrestrial ecosystems which serve as important storage pools for a long-term legacy of natural and anthropogenic Hg release to the environment. The goal of this study was to evaluate the integrated effects of 80 y of different vegetative type on Hg accumulation and partitioning in terrestrial ecosystems by comparing Hg concentrations and pools of two adjacent forests: a coniferous Douglas fir (Pseudotsuga menziesii) and a deciduous red alder (Alnus rubra) stand. These stands grew for > 80 y in close proximity (200 m) with identical site histories, soil parent materials, and atmospheric exposure. Results showed that the Douglas fir stand was characterized by significantly higher Hg concentrations and Hg : C ratios in aboveground biomass compared to the deciduous red alder forest. For foliage, higher Hg concentrations (plus 43 μg kg–1) were expected due to foliage age, but Hg concentrations also were higher in woody tissues (by 2 to 18 μg kg–1) indicating increased uptake of atmospheric Hg by coniferous tissues. These differences were reflected—and further increased—in litter horizons where Hg-concentration differences increased in highly decomposed litter to > 200 μg kg–1. In soils, no difference in concentrations of Hg was observed, but Hg : C ratios were consistently higher in the coniferous Douglas fir. Estimation of pool sizes of C and Hg in soils and at the whole ecosystem level showed that considerably smaller C pools in the coniferous stand as a result of faster C turnover and lower productivity did not lead to corresponding declines in Hg-pool sizes. The partitioning of Hg among ecosystem components—including distribution between aboveground and belowground components and distribution through the soil profile—was largely unaffected by forest type. Methyl-Hg concentrations observed in litter layers were also significantly higher in litter of Douglas fir, along with a higher proportion of methylated Hg of total Hg. In soils, methyl-Hg concentrations were similar in both stands. Comparison of these adjacent forest stands highlights that vegetation type affects concentrations of total Hg in otherwise equivalent sites and that differences also exist in respect to methylated Hg.
Renal excretion of emtricitabine II. effect of trimethoprim on emtricitabine excretion: In vitro and in vivo studies.

Abstract The potential interaction between the nucleoside analog emtricitabine (FTC) and trimethoprim (TMP) was assessed in the isolated perfused rat kidney (IPK) model and in vivo in rats. IPK experiments were performed with FTC alone (2 µg/mL) and in the presence of increasing concentrations of TMP (1–10 µg/mL). TMP inhibited FTC excretion in a concentration dependent manner. The IC 50 (TMP concentration associated with a 50% reduction in FTC excretion) was 1.86 ± 0.37 µg/mL. The results were compared to whole animal studies in rats. Animals received an IV dose of FTC (1 mg/kg) with or without pretreatment with TMP (25 mg/kg). TMP coadministration significantly decreased FTC clearance (7.4 ± 1.2 mL/min/kg to 2.7 ± 0.53 mL/min/kg), and elimination half‐life was significantly increased (58 ± 12 min to 215 ± 44 min). A good correlation was obtained between IPK findings and in vivo data, as FTC renal clearance was reduced ∼60% in the presence of TMP in both studies. Based on this investigation, TMP would be expected to inhibit the renal excretion of FTC when the two compounds are coadministered, resulting in increased plasma exposure of FTC. However, the clinical significance of this finding remains to be elucidated. © 2008 Wiley‐Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:5411–5420, 2008
Plasma Total Homocysteine Levels and Cranial Magnetic Resonance Imaging Findings in Elderly Persons: The Cardiovascular Health Study

Background An elevated plasma total homocysteine (tHcy) level is associated with an increased risk of vascular disease. Some studies have shown associations between tHcy level and small-vessel disease of the brain on magnetic resonance imaging (MRI). Design In the Cardiovascular Health Study, 622 elderly participants without a history of transient ischemic attack or stroke had results for tHcy level and cranial MRI. We sought associations between tHcy level and MRI findings of ventricular grade, sulcal grade, white matter grade, and infarcts. We controlled for other factors, including levels of creatinine, folate, and vitamins B 6 and B 12 and methylenetetrahydrofolate reductase genotype. Results After controlling for age and sex, tHcy level was not associated with the individual MRI findings. Further adjustments for other factors and other blood tests had little effect on these findings. The only significant finding was a linear trend across quintiles of tHcy level and a pattern of MRI findings combining infarcts and high white matter grade. The linear trend remained significant after controlling for other risk factors and atherosclerotic markers (top quintile vs bottom quintile odds ratio, 3.3; 95% confidence interval, 0.96-11.20; P = .04 for linear trend) but was slightly diminished after further controlling for creatinine, folate, and vitamins B 6 and B 12 (odds ratio, 3.2; 95% confidence interval, 0.81-13.10; P = .07 for linear trend). Conclusion We were unable to confirm the results of previous studies with respect to tHcy level and individual MRI findings, although an association was seen for an MRI pattern combining infarcts and high white matter grade.
Density functional calculations of the binding energies and adatom diffusion on strained AlN (0001) and GaN (0001) surfaces

Density functional theory calculations were carried out to study the binding energies and diffusion barriers for various adatoms on AlN and GaN (0001) surfaces. The binding energies and potential energy surfaces were investigated for Al, Ga, and N adatoms on both Al (Ga) terminated and N terminated (0001) surfaces of AlN (GaN). Calculations for the diffusion paths and diffusion energy barriers for Al, Ga, and N adatoms on AlN and GaN were performed. It was found that the N adatom on N terminated AlN and GaN surfaces faces a high diffusion barrier due to strong N-N bond. The Al and Ga adatom on Al (Ga) terminated AlN (GaN) surfaces showed lower diffusion barriers due to the weak metallic bonds. However, the diffusion barrier for an Al adatom was always larger than that of a Ga adatom on any surface. The surfaces were also subjected to a hydrostatic compressive and tensile strain in the range of 0 to 5% to investigate the effect of strain on diffusion barriers. The diffusion energy barrier for N adatom on N terminated AlN and GaN surfaces decreased when the strain state was changed from tensile to compressive. In contrast, Al and Ga adatoms show continuous increase in diffusion barriers from tensile to compressively strained Al (Ga) terminated AlN (GaN) surfaces.
Liquid optics: Oscillating lenses focus fast

Researchers demonstrate fast optical focusing using an oscillating liquid lens. The method could lead to the development of three-dimensional imaging instruments with rapid data collection.
Mineralogical, Textural and Compositional Data on the Alteration of Basaltic Glass From Kilauea, Hawaii to 300°C: Insights to the Corrosion of a Borosilicate Glass Waste-Form

Mineralogical, textural and compositional data accompanying greenschist facies metamorphism (to 300°C) of basalts of the East Rift Zone (ERZ), Kilauea, Hawaii may be evaluated relative to published and experimental results for the surface corrosion of borosilicate glass. The ERZ alteration sequence is dominated by intermittent palagonite, interlayered smectite-chlorite, chlorite, and actinolite-epidote-anhydrite. Alteration is best developed in fractures and vesicles where surface reaction layers root on the glass matrix forming rinds in excess of 100 microns thick. Fractures control fluid circulation and the alteration sequence. Proximal to the glass surface, palagonite, Fe-Ti oxides and clays replace fresh glass as the surface reaction layer migrates inwards; away from the surface, amphibole, anhydrite, quartz and calcite crystallize from hydrothermal fluids in contact with the glass. The texture and composition of basaltic glass surfaces are similar to those of a SRL-165 glass leached statically for sixty days at 150°C. While the ERZ reservoir is a complex open system, conservative comparisons between the alteration of ERZ and synthetic borosilicate glass are warranted.
Observer Bias in Anuran Call Surveys

Amphibian monitoring programs rarely question the quality of data obtained by observers and often ignore observer bias. In order to test for bias in amphibian call surveys, we sampled 29 clusters of wetlands from the Rainwater Basin, Nebraska, USA, totaling 228 functionally connected wetlands. Sampling consisted of 3-minute stops where volunteers recorded species heard and made digital recordings. Based on 627 samples, we examined 3 types of observer bias: omission, false inclusion (commission), and incorrect identification. Misidentification rates ranged from 4.2% to 18.3%. Relatively high and unquantified error rates can negatively affect the ability of monitoring programs to accurately detect the population or abundance trends for which most were designed.
On the algebra of interactive fuzzy numbers

Abstract This paper discusses basic arithmetic of interactive fuzzy numbers which are values of fuzzy variables. We argue that one should use the joint distribution, and not necessarily only the marginals in the extension principle, to perform these operations. Since in practice we usually do not know the joint we suggest default methods, involving an approximate joint distribution or the classical extension principle, to calculate M + N , M N , and evaluate M ⩽ N , M = N , etc. for positively (negatively)associated fuzzy numbers M and N . We also introduce a measure of association between fuzzy variables.
An intransitive expectations-based bayesian variant of prospect theory

Psychological experiments have established that the classical expected utility model appears descriptively inadequate. Viscusi's prospective reference theory attempts to reconcile the expected utility model with many of these experiments by supposing that individuals have prior expectations about the utility they can expect to get from lottery payoffs. Bayesian theory then implies that individuals revise lottery probabilities in light of these prior expectations before choosing among lotteries so as to maximize expected utility. But Viscusi's theory cannot account for nonmonotonic or intransitive behavior. This article develops an extension of Viscusi's model with correlated prior beliefs that does account for nonmonotonic and intransitive behavior.
Periodic waves in a Hertzian chain

Strongly nonlinear periodic waves are investigated in an initially compressed chain of spheres under Hertz contact. A harmonic excitation force disturbs the first grain with an amplitude comparable to the initial compression and the steady strain-wave profiles at large distances from this disturbance are compared with predictions from the long wave approximation. Two qualitatively different types of quasi-stationary periodic waves are apparent in the system: one with minimum and maximum strain values above the static value and one whose minimum strain is below and maximum value is above the initial strain. From the frequency spectrums of the calculated force between particles, new forcing functions are constructed that allow rapid formation of quasi-stationary strongly nonlinear periodic waves.
Training set selection with multiple out-of-plane rotation parameters

We present a new approach to training set selection for general out-of-plane rotation distortion. This approach is mathematically related to distortion-invariant filter design and acts to simplify filter design and improve discrimination performance. It is also applicable to most other model based rotation-invariant filter designs. We develop the approach in a 3-D space with 3-D objects. Given a target object, it is first uniformly rotated about a coordinate axis and sampled. This is denoted as an in- plane rotation set. The set is then rotated in spherical coordinates corresponding in direction to the vertices of a platonic solid. All the rotated objects are correlated to obtain a correlation matrix. The correlation matrix is approximately cyclic Toeplitz dependent on the training set ordering. Its eigenvectors are approximately the Kronecker product of subsets of Fourier Vectors. The training set is intended to be orthographically projected to 2-D images. A filter family is defined by multiplying the training set matrix times the eigenvector matrix. The resulting correlation response at the origin is constant magnitude and linear in phase. As with linear phase coefficient composite filters, we expect such a filter family to demonstrate inherent discrimination against clutter and high signal-to-noise ration in detection.
Experiences with Commercial Production Scale Operation of Dissolving Metal Reduction Using Lithium Metal and Liquid Ammonia

The final step which generates free base in the synthesis of Sumanirole Maleate (PNU-95666E) consists of a cryogenic dissolving metal reduction using lithium metal and liquid ammonia. This chemistry was new to the Pfizer API production plant. Due to the hazards associated with the handling of lithium metal and ammonia gas at cryogenic reaction temperature, special challenges were encountered related to the design of the equipment, choice and handling of materials, operations, waste treatment, and both safety and economic issues. The topics discussed in this article include the use of Li instead of Na or K, impact of the choice of physical form of lithium metal, design of the lithium addition apparatus, and problems experienced during the addition. We also discuss techniques for addition of ammonia to the reactor, evaporation of ammonia from the reaction mixture, options for ammonia disposal, and internal reuse of ammonia. Comments on hazards for this reaction are also provided. It is hoped that this docum...
Small Heteroborane Cluster Systems. 8. Preparation of Phosphaborane Clusters from the Reaction of Polyhedral Boranes with Low-Coordinate Phosphorus Compounds: Reaction Chemistry of Phosphaalkynes with Decaborane(14)1

The room-temperature reaction of equimolar quantities of phosphaalkyne RC⋮P (2a; R = tBu; 2b, R = adamantyl) with the decaborane(12)−Lewis base adduct B10H12·2CH3CN (3) resulted in the formation of new phosphaborane compounds (phosphine−methylene ylides), nido-RC(H)PB10H13 (4a, R = tBu; 4b, R = adamantyl), in good yield (approximately 50% each). These slightly air-sensitive compounds were fully characterized by 1H, 11B, 13C, and 31P NMR, 2D 11B−11B COSY NMR, FT-IR, and mass spectroscopic analyses. The structures of 4a and 4b are proposed to consist of a nido-PB10 framework formally based upon a 26-skeletal-electron nido-[B11H11]- parent compound. Only the phosphorus atom was observed to be incorporated into the polyhedral framework with an exopolyhedral C(H)R group doubly bound to the cage phosphorus atom. Two related mechanisms are proposed to account for the observed products from these reactions.
Reporting crime to the police, 1973–2005: a multivariate analysis of long‐term trends in the National Crime Survey (NCS) and National Crime Victimization Survey (NCVS)

Although many efforts have been made during the past several decades to increase the reporting of crime to the police, we know little about the nature of long-term crime-reporting trends. Most research in this area has been limited to specific crime types (e.g., sexual assault), or it has not taken into account possible changes in the characteristics of incidents associated with police notification. In this article, we advance knowledge about long-term trends in the reporting of crime to the police by using data from the National Crime Survey (NCS) and the National Crime Victimization Survey (NCVS) and methods that take into account possible changes in the factors that affect reporting at the individual and incident level as well as changes in survey methodology. Using data from 1973 to 2005, our findings show that significant increases have occurred in the likelihood of police notification for sexual assault crimes as well as for other forms of assault and that these increases were observed for violence against women and violence against men, stranger and nonstranger violence, as well as crimes experienced by members of different racial and ethnic groups. The reporting of property victimization (i.e., motor vehicle theft, burglary, and larceny) also increased across time. Overall, observed increases in crime reporting account for about half of the divergence between the NCVS and the Uniform Crime Reporting Program (UCR) in the estimated magnitude of the 1990s crime decline—a result that highlights the need to corroborate findings about crime trends from multiple data sources.
A coincidence counting study of spontaneous desorption

Abstract The “spontaneous” emission of ions and photons from surfaces was studied with coincidence counting time-of-flight mass spectrometry. Photons were produced by the spontaneous desorption process with an experimental yield of about 0.01%. Both positive and negative secondary ion yields were measured under various conditions. Results imply classes of desorption events. This may indicate that several types of primary ions are being produced during a single experiment. There was no detectable change in the types of primary ions involved in the spontaneous desorption process as a function of sample potential within the range examined. Positive and negative valine molecular ion yields were found to be similar.
Influence of Prior Level of Meaningfulness on Acquisition of New Meaning

Summary.-Previous research has demonstrated that, when a word which has a neutral evaluative meaning is paired in a learning task with 3 word that has either positive or negative evaluative meaning, the neutral word acquires a new component of mezning. Research in verbal learning has shown chat initial level of associative meaning influences the rate of learning of new materials. The objective of che present investigation was to select CVC syllables at LWO levels of associative meaning and pair them with words of positive and negative evzluative meaning to determine the influence of associative meaning on the acquisition of evaluative meaning. One group of college students received CVCs low in meaningfulness and one high in meaningfulness. After a conditioning period, change ~n evaluative meaning of the CVCs was assessed with a semantic differenrlal. Data supported the hypothesis that conditioning would be related to initial level of meaningfulness. Change was significantly greater for the low meaningfulness CVCs than for the high, but both groups showed conditioning.
Urinary acid phosphatase secretion under different arousal conditions.

Seventy-three undergraduate males were randomly assigned to five different conditions, sexual, anxiety, aggressive, and laughter arousals and a control group, as a test of the hypothesis that urinary acid phosphatase is a specific indicator of sexual arousal. Pre- and post-arousal urine samples were analyzed for the amount of urinary acid phosphatase (AP) present, and significant increases occurred only in the sexual arousal condition. Both general and specific elements of arousal as well as a possible link between sexual arousal and anxiety are discussed. These findings support earlier results of studies in this area.
Interrelated effects of cysteine, thyroxin, and substrate on growth rate of influenza virus in tissue culture.

In cultures of chorioallantoic membrane in simple balanced salt solution, cysteine at a concentration of 0.5 to 1.0 mg/ml. interferes with the utilization of pyruvate and glutamate for tissue metabolism and growth of influenza virus. Thyroxin stimulates growth of virus and causes partial or complete reversal of the inhibitory effect of cysteine on virus reproduction. When glucose is employed as the substrate, cysteine is much less inhibitory to tissue respiration and virus, and thyroxin is found to be less effective in accelerating virus reproduction. Thyroxin was also found to increase slightly the rate of virus synthesis in tissue cultures partially inhibited with 2,4-dinitrophenol or malonate.
H01 Prospective diagnosis of huntington disease: prognostic indicators and directions for future study

Background We provide a summary of study-wide variables which were predictive of the time to HD diagnosis (DCL=4). Aims Two aspects of each predictor were considered: (1) the ability of the variable at baseline (only) to predict diagnosis, and (2) the ability of the change in the variable to predict diagnosis. Methods All analyses adjusted for age at baseline, gender, years of education, motor examiner experience and CAP. There were 44 baseline and 36 longitudinal variables from five sections (cognitive, functional, imaging, motor, and psychiatric) which were examined in the analysis. Most variables were significant as baseline predictors, whereas variables from motor, cognitive and functional sections were significant as longitudinal predictors. These include: motor score, TFC, FAS, symbol digit, stroop word, stroop interference, stroop colour, verbal fluency, trails B time, dominant index finger speeded tapping, alternating thumbs paced tapping, 2-back discriminability, chooser two-choice movement time, dominant index finger paced tapping, and negative emotion recognition. We also present an evaluation of the prognostic potential of the baseline variables with a type of longitudinal receiver operating characteristic (ROC) curve analysis. Results Results of this analysis showed that variables from the imaging and cognitive sections had relatively high prognostic potential. These included: globus/ICV ratio, alternating thumbs paced tapping, striatum/ICV ratio, putamen/ICV ratio, caudate/ICV ratio, dominant index finger paced tapping, and symbol digit. Conclusions Findings are discussed in terms of clinical trial design and directions for future research study in observational studies such as ENROLL.
Preferential modification of GC boxes by benzo[a]pyrene-7,8-diol-9,10-epoxide.

The distribution of binding sites for the ultimate carcinogen anti-benzo[a]pyrene-7,8-diol-9, 10-epoxide(BPDE-l) in the 5′ region of the Chinese hamster ovary aprt gene has been determined. A plasmid (pGAL) containing the entire hamster aprt gene including the 3′ and 5′ flanking regions was inserted into the BamHl site of the multiple cloning site of pGEM so that the T7 promoter was 5′ to the aprt gene. In vitro transcription of BPDE-l-modified pGAL, using the T7 RNA polymerase, revealed two prominent transcriptional stop sites. One of these sites was located in the first exon of the aprt gene, whereas the second transcriptional stop was located approximately 150 bp upstream from the translational start site. This latter region contains two perfect GC-box consensus sequences that are potential Sp1 binding sites. Using a specific laser cutting technique to map BPDE-I DNA binding sites in the 5′ flanking region of the aprt gene, we found that the DNA region containing the GC-box consensus sequences was indeed a hot spot for BPDE-I modification.
Salvage of sensation in a hallux-to-thumb transfer by nerve tube reconstruction.

We report a patient in whom, at 3 years after successful reconstruction of a right avulsed thumb with a microvascular hallux transfer, the insensate transfer had sensibility restored. The radial sensory and both volar digital nerves of the thumb were reconstructed using 2.3-mm–diameter bioabsorbable neural conduits. At 30 months after reconstruction, static 2-point discrimination of the hallux was 4 mm at 14.7 g/mm 2 in this now 42-year-old right-handed man. The cutaneous pressure threshold for 1-point static touch was 0.7 g/mm 2 . There were no painful neuromas at the nerve reconstruction sites.
Ethnic Pluralism as an Organizing Principle of the Ethiopian Federation

In 1991 the Ethiopian government employed ethnic pluralism as an organizing principle, creating multiple ethnic-based territorial units with a “right of secession” provision. Ethiopians are watching this experiment with considerable apprehension. This paper: (1) provides a concise historical background of ethnic relations in Ethiopia, (2) examines the type of ethnic federal state established in Ethiopia, and (3) points out some problems encountered with ethnicity as an organizing principle and attempts a preliminary assessment of the ethnic-based federal experiment. The sources of data for this paper include public documents, fieldwork, and interviews with 30 knowledgeable Ethiopians in Addis Ababa. I spent several months during 2000–2002 observing political developments in the country as they pertain to ethnic federalism. Within Africa, a nation-state fully acknowledging and based on ethnic pluralism is unique. Thus far, the Ethiopian federation appears to have undercut the drive for secession by largely removing its rallying cause, manifest ethnic oppression. Nonetheless, the fact that the ruling group comes predominantly from a small ethnic group has raised serious protest from other ethnic groups, larger and smaller. Its use of democratic centralism has also undermined effective decentralization and democratization. Ethnic pluralism as an organizing principle underpinning the federal government in Ethiopia is a fragile and perilous experiment.
Physiological Induction of a β-Adrenergic Receptor Kinase Inhibitor Transgene Preserves β-Adrenergic Responsiveness in Pressure-Overload Cardiac Hypertrophy

Background —Transgenic mice with constitutive myocardium-targeted expression of a peptide inhibitor of the β-adrenergic receptor kinase (βARKct) have increased in vivo cardiac function and enhanced β-adrenergic receptor (βAR) responsiveness. Methods and Results —In the present study, we created transgenic mice with myocardium-targeted βARKct transgene expression under control of the CARP (cardiac ankyrin repeat protein) promoter, which is active during cardiac development and inactive in the normal adult mouse heart. Consistent with this, adult CARP-βARKct transgenic mice have normal in vivo cardiac contractility and βAR responsiveness indistinguishable from their nontransgenic littermates (NLCs). However, because CARP is in a group of fetal genes activated in the adult ventricle during hypertrophy, we subjected animals to transverse aortic constriction (TAC) to induce pressure overload. Seven days after TAC, CARP-βARKct hearts had elevations in left ventricular mass similar to those in NLCs; however, TAC did induce demonstrable βARKct expression in the transgenic hearts. TAC in NLC mice resulted in an upregulation of myocardial βARK1 and a loss of βAR-mediated inotropic reserve. Importantly, although βARK1 was increased in the hypertrophic CARP-βARKct mice, the in vivo loss of βAR responsiveness was not seen after induced βARKct expression. Conclusions —These results demonstrate that acute βARK1 inhibition can restore lost myocardial βAR responsiveness and inotropic reserve in vivo. Furthermore, these mice demonstrate the novel utility of the CARP promoter as an inducible element responsive to pathophysiological conditions in the adult heart.
Negotiated self-authenticated experience and homeland travel loyalty: implications for relationship marketing.

This study examines the relationship between negotiated self-authenticated experiences on attitudinal and behavioural loyalty. A purposive sample of Indian diaspora, based in the USA, is examined. The results unpack need for a negotiated self-authenticated experience through engagement with the homeland's perceived objectively authentic settings and environments. Furthermore, its significant influence on attitudinal loyalty is unveiled.
Understanding hearing through deafness

Twenty-five years ago, many people thought that auditory prostheses were too crude to ever benefit auditory neuroscience. One skeptic thought that trying to understand auditory processing by using the artificial pattern of neural activation through a cochlear implant was like trying to understand how a television tuner works by applying a lightning bolt to the antenna. Recent papers in PNAS (1, 11) have shown the gains auditory prostheses have made in 25 years, in terms of practical benefit (i.e., restoring hearing to deaf people) and as a valuable tool for neuroscience. In this issue of PNAS, Rouger et al. (1) show that deaf people have superior lip-reading abilities and superior audiovisual integration compared with those with normal hearing and that they maintain superior lip-reading performance even after cochlear implantation. The development of the cochlear implant allowed for this unique perspective on auditory and visual integration.
First Principles Computation of Lattice Energies of Organic Solids: The Benzene Crystal

We provide a first-principles methodology to obtain converged results for the lattice energy of crystals of small, neutral organic molecules. In particular, we determine the lattice energy of crystalline benzene using an additive system based on the individual interaction energies of benzene dimers. Enthalpy corrections are estimated so that the lattice energy can be directly compared to the experimentally determined sublimation energy. Our best estimate of the sublimation energy is 49.4 kJ mol(-1), just over the typical experimentally reported values of 43-47 kJ mol(-1). Our results underscore the necessity of using highly correlated electronic structure methods to determine thermodynamic properties within chemical accuracy. The first coordination sphere contributes about 90 % of the total lattice energy, and the second coordination sphere contributes the remaining 10 %. Three-body interactions are determined to be negligible.
A pauper's callback scheme

Abstract This paper discusses the implementation of callback schema in software, including a protocol for having one computer call another, and describes two methods to authenticate users without sending passwords over a telephone line. This decreases the probability of a wiretapper obtaining a valid user password.
On reduction of asynchronous systems

Abstract In this paper, we give a formal treatment of the reduction idea in Lipton's paper, and investigate its application in proving correctness of asynchronous systems. In a complex system, it is both tempting and convenient to assume that certain sequences of actions behave like single indivisible or instantaneous actions. Such conceptual reduction of sequences of relatively small actions to single occurrences of relatively large actions is encountered very often in computer science. For asynchronous systems, reduction is particularly appealing because it helps to reduce the amount of interleaving of actions involved and also the complexity of the systems, thereby making correctness proofs more tractable. However, reduction is also very dangerous for it could easily lead to erroneous and disastrous conclusions about systems. We establish, in this paper, simple and general sufficient conditions for reduction under which correctness is preserved, and any conclusions obtained about the correctness of the reduced systems are also valid for the original systems, as far as deadlock-freedom, homing, determinacy and the Church-Rosser property are concerned. We also show that the results in Lipton's paper are special cases of some of our results here.
Fetal brain development of twins assessed in utero by ultrasound: implications for schizophrenia

There is evidence that some forms of schizophrenia are due to alterations of in utero brain development. Given the concordance rate for schizophrenia in monozygotic twins is approx. 45%, it is not clear how a shared genetic predisposition for schizophrenia and a shared in utero environment might selectively lead to schizophrenia in one but not the other twin in a monozygotic twin pair. This study was undertaken to test the hypothesis that there is a difference in brain development between twins in a monozygotic twin pair that may contribute to the observed concordance rates for schizophrenia. Fetal ultrasound measures of brain (biparietal diameter, head circumference, ventricular width) and body size (femur length, abdominal circumference) obtained during the second trimester of fetal development were retrospectively analyzed in 41 monozygotic and 103 dizygotic twin pairs. In monozygotic twin pairs, there was a significant difference in measures of biparietal diameter, head circumference, and ventricular width, as well as in femur length and abdominal circumference, between twins. There was a similar difference in dizygotic twin pairs. These results indicate that in monozygotic twins, brain development is not identical. This difference in brain development may contribute to the observed concordance rates in monozygotic twins with schizophrenia.
The Influence of Thickness and Wavelength on the Mechanical Properties of a Compositionally Modulated Ceramic Thin Film

The hardness and modulus of thin (<1 ..mu..m) ceramic films have been investigated using the differential mechanical properties microprobe (DMPM). The DMPM consists of a computer controlled ultra-low load indentation system with a special system that allows the elastic stiffness of the contact to be determined continuously during the indentation process. The films were deposited in a molecular beam epitaxy (MBE) system utilizing unique high temperature effusion cells. Two specimens have been studied. The fist is a wedge shaped layer of amorphous Al/sub 2/O/sub 3/ on a silicon substrate. The thickness of the layer varies from 0 to 990 nm at the two extreme sides of a 3 in. silicon wafer. The effect of layer thickness on the hardness and modulus as measured with the DMPM has been quantified for this system. The second specimen is made up of 38 repetitions of alternating layers of crystalline TiO/sub 2/ and amorphous Al/sub 2/O/sub 3/. The wavelength of the composition modulation and the thickness of the film varies uniformly from 0 to 38 nm and from 0 to 1460 nm respectively across the 3 in. diameter of the silicon substrate. 17 refs., 5 figs.
Effects of low-frequency wave interactions on intraseasonal oscillations

Abstract Intraseasonal oscillations (ISOs) control much of the large-scale variability of convection in the Tropics on time scales of about 15–100 days. These disturbances are often thought to be dominated by eastward-propagating modes, especially during austral summer, but disturbances that propagate westward are also important. This work demonstrates by means of a multiple linear regression model and a brief case study that eastward- and westward-moving intraseasonal modes often cooperatively interact with one another to produce many of the characteristics of the observed Southern Hemisphere summer ISO. These interactions appear to be facilitated by topography and/or by the convective anomalies that are cooperatively induced by the eastward- and the westward-moving components of the oscillations. These interactions do not occur during every period of intraseasonal convective activity, but they do commonly occur during periods of high-amplitude convective anomalies. This analysis shows that eastward- and...
Copernicus observations of the Ap star Epsilon Ursae Majoris

Spectral scans of the Ap star Epsilon UMa made with the Copernicus satellite show strong line blanketing from profuse Cr II and Fe II lines. In the spectral region covering 1900 to 3000 A, about 500 lines are present which suppress the apparent continuum by at least 15-30%. An accurate line-identification list is compiled showing Eu II present in addition to Mn II and Ni II. The identification of Eu II, however, rests on very stringent identification limits for Fe II. If these are relaxed, the existence of Eu II is dubious. There are no broad features in this spectral region which would suggest strong photoionization discontinuities by metals, but one feature near 2137 A might contain the photoionization edge due to Cr I 5S lying 0.94 eV above the ground level. However, a significant correlation between the line-blanketing strength and the amplitude of the OAO-2 ultraviolet light curves was found such that both monotonically increase in the same proportion toward shorter wavelengths. This gives additional strength to the suggestion that variations in the metal line-blanketing cause the observed photometric variations.
Student's t Vector Random Fields with Power-Law and Log-Law Decaying Direct and Cross Covariances

This article deals with the Student's t vector random field, which is formulated as a scale mixture of Gaussian vector random fields, and whose finite-dimensional distributions decay in power-law and have heavy tails. There are two classes of Student's t vector random fields, one with second-order moments, and the other without a second-order moment. A Cauchy vector random field is an example of Student's t vector random fields without a first-order moment, and is also an example of Stable vector random fields. A second-order Student's t vector random field allows for any given correlation structure, just as a Gaussian vector random field does. We propose four types of covariance matrix structures for second-order Student's t vector random fields, which decay in power-law or log-law.
Mammary transfer of 203 Hg from mothers to brains of nursing rats.

SummaryAt the 16th day of lactation, rats were force-fed a tracer dose of 203Hg as CH3203HgCl and allowed to continue to nurse their pups. After 1, 2, 3, and 5 days of nursing, representative pups were killed and brains obtained. The mother was also killed at the end of the study and its brain and those from the pups were separated into brain parts and radioactivities determined. In the mother, the concentrations of 203Hg ranged from 0.117 in the medulla to 0.167 in the hypothalamus and 0.205% of dose/g tissue in the pituitary. In the pups, the quantity of labeled mercury deposited in the brain or brain parts increased from 1 day to 5 days of suckling. The concentration (% of dose/g of brain or brain part) also increased with succeeding day of nursing so that at the end of 5 days the pup brain contained a higher concentration than their mothers' brain (0.307 vs 0.131). Correspondingly, pup brain parts contained greater concentrations of labeled mercury than their mothers' brain parts: Cerebrum, 0.287 vs 0...
A markov chain analysis of caries process with consideration for the effect of restoration

Abstract 1. (1) A total of 1080 dental records on the maxillary second premolar of 184 grade and high school pupils (105 boys and 79 girls) observed in six-month time intervals by a single examiner was used for this study. 2. (2) An absorbing Markov chain was used to analyze the progression of the caries process with the missing tooth state (11111) and the ergodic set of restoration states as absorbing states. 3. (3) An ergodic Markov chain was used to study the caries behaviour under the influence of restoration. 4. (4) It was found that the occupancy of patterns was quite selective. No lingual-buccal decay was observed. In addition to the healthy (00000) and the missing (11111) states, the maxillary second premolar occupied six states, namely, (10000), (01000), (00100), (11000), (10100),and (01100). The ergodic set of restoration states consisted of nine states, namely, (11200), (20000), (20100), (20200), (21000), (21100), (21200), (22100), and (22200). 5. (5) It was found that only five states in the absorbing chain analysis would enter into the restoration states directly. These states are (00000), (10000), (00100), (01100), and (11100), whereas states (01000), (10100), and (11000) would lead to (01100) or (11100). This peculiar behaviour of loss indicates possible negligence in patient or professional care. 6. (6) In the ergodic analysis, four states formed a cyclic chain. These states are (21100), (21200), (22100), and (22200). The limiting probabilities corresponding to these four states are 0.16, 0.08, 0.33, and 0.43 respectively. 7. (7) The effect of restoration was demonstrated in the paper. We shall cite one example. The average time to remain as-is for an occlusal decay (10000) is about 1.75 yr, as compared to 4 yr for the corresponding restoration (20000). 8. (8) The information gained from analysis of this kind may be used as a tool in actuarial assessment of dental care programmes, teaching in clinical and preventive dentistry concerning dynamics of caries progression, and also as a research tool for assessing durability of restorative techniques and materials and the quality of dental care.
MAX UHLE AND TAMBO COLORADO A CENTURY LATER

In 1901 Max Uhle, the “Father of Peruvian Archeology,” spent several weeks mapping, photographing, and studying the Inca site of Tambo Colorado and its surroundings. Because the site has suffered noticeable deterioration and damage in the intervening century, Uhle’s plans, photographs, and notes are of particular importance to anyone investigating Tambo Colorado. But more important than the historic value of Uhle’s documentation is the superior quality of his work. His plans are of an astonishing accuracy and his observations and reflections most thoughtful and astute. The present article is a critical appreciation of Uhle’s work at Tambo Colorado and compares it to current findings.
The effects of femoral graft placement on cartilage thickness after anterior cruciate ligament reconstruction

Altered joint motion has been thought to be a contributing factor in the long-term development of osteoarthritis after ACL reconstruction. While many studies have quantified knee kinematics after ACL injury and reconstruction, there is limited in vivo data characterizing the effects of altered knee motion on cartilage thickness distributions. Thus, the objective of this study was to compare cartilage thickness distributions in two groups of patients with ACL reconstruction: one group in which subjects received a non-anatomic reconstruction that resulted in abnormal joint motion and another group in which subjects received an anatomically placed graft that more closely restored normal knee motion. Ten patients with anatomic graft placement (mean follow-up: 20 months) and 12 patients with non-anatomic graft placement (mean follow-up: 18 months) were scanned using high-resolution MR imaging. These images were used to generate 3D mesh models of both knees of each patient. The operative and contralateral knee models were registered to each other and a grid sampling system was used to make site-specific comparisons of cartilage thickness. Patients in the non-anatomic graft placement group demonstrated a significant decrease in cartilage thickness along the medial intercondylar notch in the operative knee relative to the intact knee (8%). In the anatomic graft placement group, no significant changes were observed. These findings suggest that restoring normal knee motion after ACL injury may help to slow the progression of degeneration. Therefore, graft placement may have important implications on the development of osteoarthritis after ACL reconstruction.
BACE1 influences debris clearance and axonal regeneration in injured peripheral nerve.

During 3 years, my research activities in Jack Griffin's laboratory focused on the influence of β-amyloid precursor protein cleaving enzyme 1 (BACE1) on the degeneration/regeneration of sciatic nerve of mice. Here, potential mechanisms of how BACE1 enzymatic activity influences these processes are discussed.
The Lack of Effect of Dietary Inositol in Depressing Liver Lipids in the Hen

Abstract The “fatty liver syndrome” originally described by Couch (1956) has attracted considerable attention but remains obscure and poorly defined. The syndrome is characterized by a decreased rate of egg production in an apparently healthy flock and autopsy of affected birds reveals excessive amounts of abdominal fat and enlarged fatty livers (Reedy, 1968). Attempts to produce this syndrome experimentally have been unsuccessful (Quisenberry et al., 1967). Consequently it has been impossible to critically study the syndrome or the factors which may prevent or cure the symptoms. A number of field experiments have been conducted which indicate that supplementation of diets with vitamin E, vitamin B12 and choline is effective in overcoming the fatty liver syndrome (Deacon, 1968; Parker and Deacon, 1968; Reedy, 1968). However, since virtually all of these trials are lacking in appropriate controls, it is impossible to arrive at any clear-cut conclusions regarding the efficacy of this treatment. Laboratory…
Relationship of antimicrobial control policies and hospital and infection control characteristics to antimicrobial resistance rates.

• BACKGROUND Antibiotic misuse and noncompliance with infection control precautions have contributed to increasing levels of antimicrobial resistance in hospitals. • OBJECTIVES To assess the extent to which resistance is monitored in infection control programs and to correlate resistance rates with characteristics of antimicrobial control policies, provider attitudes and practices, and systems-level indicators of implementation of the hand hygiene guideline of the Centers for Disease Control and Prevention. • METHODS An on-site survey of intensive care unit staff and infection control directors of 33 hospitals in the United States was conducted. The following data were collected: antimicrobial control policies; rates during the previous 12 months of methicillin-resistant Staphylococcus aureus, vancomycinresistant enterococci, and ceftazidime-resistant Klebsiella pneumoniae; an implementation score of systems-level efforts to implement the guideline; staff attitudes toward practice guidelines; and observations of staff hand hygiene. Variables associated with resistance rates were examined for independent effects by using logistic regression. • RESULTS Resistance rates for S aureus, enterococci, and K pneumoniae were 52.5%, 18.2%, and 16.0%, respectively. Ten (30.3%) hospitals had an antibiotic control policy. No statistically significant correlation was observed between staff attitudes toward practice guidelines, observed hand hygiene behavior, or having an antibiotic use policy and resistance rates. In logistic regression analysis, higher scores on measures of systems-level efforts to implement the guideline were associated with lower rates of resistant S aureus and enterococci (P=.046). • CONCLUSIONS Organizational-level factors independent of the practices of individual clinicians may be associated with rates of antimicrobial resistance. (American Journal of Critical Care. 2007;16:110-120)