cssi/SciSciGPT-SciSciNet huggingface dataset:
Equations of motion for nonholonomic, constrained dynamical systems via Gauss's principle

In this paper we develop an analytical set of equations to describe the motion of discrete dynamical systems subjected to holonomic and/or nonholonomic Pfaffian equality constraints. These equations are obtained by using Gauss’s Principle to recast the problem of the constrained motion of dynamical systems in the form of a quadratic programming problem. The closed-form solution to this programming problem then explicitly yields the equations that describe the time evolution of constrained linear and nonlinear mechanical systems. The direct approach used here does not require the use of any Lagrange multipliers, and the resulting equations are expressed in terms of two different classes of generalized inverses—the first class pertinent to the constraints, the second to the dynamics of the motion. These equations can be numerically solved using any of the standard numerical techniques for solving differential equations. A closed-form analytical expression for the constraint forces required for a given mechanical system to satisfy a specific set of nonholonomic constraints is also provided. An example dealing with the position tracking control of a nonlinear system shows the power of the analytical results and provides new insights into application areas such as robotics, and the control of structural and mechanical systems.
Maximum sustainable yield of a density dependent sex-age-structured population model

The maximum sustainable yield of an age-structured, density dependent, sex-differentiated population is investigated. The model is based on the nonlinear version of the McKendrick [11] model introduced by Gurtin and MacCamy [8], modified to include sex-differentiated dynamics. It is determined that the maximum sustainable yield is attainable by an age specific harvesting policy in which the number of harvesting ages for males and the harvesting ages for females total at most five.
Structural and mineralogical evaluation of an experimentally produced impact crater in granite

A crater 30 cm in diameter and 4.4 cm in depth was produced upon impact of an aluminium sphere with a homogeneous granite target. The volume excavated was 748 cm3, the mass ejected 1933 g. The crater geometry is compared with previous laboratory experiments. Mineralogical investigations revealed that shock induced, microscopic fracturing is lowest in the direction of uniaxial compression, followed by a 45° profile. Due to reflections of stress waves at the free surface, the horizontal profile displayed the highest fracture index. Kinking of biotite was very common in samples close to the crater walls (≈ 50 kb). However it faded out at a distance which corresponds to approximately 10 kb. This seems to be the lower pressure limit for the formation of kink bands under shock conditions.
Risk factors for functional limitations in patients with long-standing ankylosing spondylitis

Objectives To identify risk factors for functional limitations in patients with ankylosing spondylitis (AS) of at least 20 years duration.
A mean field theory for diffusion-limited cluster formation

A mean field theory for diffusion-controlled cluster formation is presented by considering the competition among the different protions of a growing cluster for the incoming diffusive particles. This competition is shown to introduce a screening length that depends inversely on the density of the cluster. The Hausdorff dimensionality D of these clusters is shown to be (d2 + 1)/(d + 1), where dis the eudidean dimensionality. This result is in excellent agreement with that of the computer simulations of Witten and Sander and Meakin. The theory also predicts that the growth of these clusters occurs on their periphery in any d. PACS nos: 68.70,+ w, 82.70.Dd, 05.70.-a
ATP Hydrolysis Is Critical for Induction of Conformational Changes in GroEL That Expose Hydrophobic Surfaces

Abstract The degree of hydrophobic exposure in the molecular chaperone GroEL during its cycle of ATP hydrolysis was analyzed using 1,1′-bis(4-anilino)naphthalene-5,5′disulfonic acid (bisANS), a hydrophobic probe, whose fluorescence is highly sensitive to the environment. In the presence of 10 mM MgCl2 and 10 mM KCl the addition of ATP, but not ADP or AMP-PNP, resulted in a time-dependent, linear increase in the bisANS fluorescence. The rate of the increase in the bisANS fluorescence depended on the concentrations of both GroEL and the probe. The effect could be substantially inhibited by addition of excess ADP or by converting ATP to ADP using hexokinase, showing that the increase in the bisANS fluorescence was correlated with ATP hydrolysis. The rate of ATP hydrolysis catalyzed by GroEL was uncompetitively inhibited in the presence of bisANS. This uncompetitive inhibition suggests that the probe can interact with the GroEL-ATP complex. The inability of the nonhydrolyzable ATP analog, AMP-PNP, to cause a similar effect is explained by the interaction of bisANS with a transient conformational state of GroEL formed consequent to ATP hydrolysis. It is suggested that this short lived hydrophobic exposure reflects a conformational shift in GroEL that results from electrostatic repulsion between the bound products of ATP hydrolysis, and it plays an important role in the mechanism of the chaperonin cycle.
The effects of light exposure on the in vitro hepatic response to an amino acid-vitamin solution

Background: Administration of parenteral nutrition (PN) that has been irradiated with light is associated with hepatic dysfunction in rats in vivo. Using the isolated perfused rat liver, we report the in vitro hepatic response to a light-exposed amino acid-vitamin (AAV) solution, compared with a light-protected solution. Methods: The amino acid-vitamin solution (3 g Aminosyn and 2.5 mL MVI-12 added to buffer) was placed under a lamp in a beaker that was covered completely with foil (light-protected) or with a transparent wrap (light-exposed) for 24 hours before liver perfusion. Livers from adult male rats were isolated and perfused with buffer for 30 minutes, with the AAV solution for 60 minutes, and again with buffer for 30 minutes. Results: Infusion with the AAV solution resulted in decreases in bile flow rates. Compared with light-protected groups, light-exposure was associated with significantly lower bile flow rates, significant increases in biliary concentrations of oxidized glutathione (GSSG), and ...
HUBBLE SPACE TELESCOPE IMAGES OF RED MERGERS : HOW DRY ARE THEY?

Mergers between red galaxies are observed to be common in the nearby universe, and are thought to be the dominant mechanism by which massive galaxies grow their mass at late times. These "dry" mergers can be readily identified in very deep ground-based images, thanks to their extended low surface brightness tidal features. However, ground-based images lack the required resolution to determine the morphologies of the merging galaxies, and to measure the amount of dust and associated gas. We present HST ACS and WFPC2 observations of a sample of 31 bulge-dominated red-sequence galaxies at z ~ 0.1, comprised of ongoing mergers, merger remnants, and undisturbed galaxies. Nearly all galaxies have early-type morphologies and most are well-fit by r1/4 law surface brightness profiles. We find that only 10% of the galaxies show evidence for the presence of dust. The amount of cold gas (or its upper limit) is calculated from the mean color excess, assuming a simple relation between gas mass and dust mass. The gas mass is low for all galaxies, and we find that Mgas/Mstellar 3 × 104. We infer that red mergers in the nearby universe mostly involve early-type galaxies containing little cold gas and dust. This may imply that the progenitors were mostly devoid of gas and/or that feedback mechanisms are very effective in preventing the gas to cool. The lack of gas in these objects may also imply a relatively large fraction of binary black holes in the centers of massive ellipticals.
The use of radioactively labeled S III to study the blood clearance and the immune response of mice to pneumococcal polysaccharides

Abstract Methods are described for the preparation of radioactively labeled type III pneumococcal polysaccharide. Using this radioactive antigen the Farr technique was adapted for the accurate and simple measurement of nanogram amounts of either antipneumococcal polysaccharide antibodies or pneumococcal polysaccharide (S III). By use of these reagents and methods the clearance of S III from the circulation of mice was followed and the immune response of mice to S III was studied. Pneumococcal polysaccharide is cleared from the circulation of mice in a markedly heterogeneous manner. Specifically immunized mice clear polysaccharide in an accelerated fashion. 1·25 μg of passively administered rabbit anti-S III antibody resulted in a distinct increase in clearance rate. The immune response of mice to S III is characterized by a rapid (peak titers at 4–7 days) and relatively weak response. Boosting with S III at 35 days after primary immunization did not result in a secondary response.
Enhanced CP Violations in Hadronic Charm Decays

Abstract The observation of CP violation in the decay of D mesons will not necessarily be a signal of new physics. If certain strong interaction matrix elements are enhanced, in analogy to the ΔI= 1 2 rule of K decays, then CP violation will be observable in strangeness conserving decays.
Barium chromate is cytotoxic and genotoxic to human lung cells

Hexavalent chromium (Cr(VI)) compounds are widely accepted as human lung carcinogens. However, there have been few investigations of the genotoxicity of Cr(VI) in human lung cells. Moreover, our knowledge of the effects of Cr(VI) in human lung cells is further limited because the available data generally focus on the effects of only lead chromate (PbCrO4) and sodium chromate (Na2CrO4). To fully understand these carcinogenic compounds, the genotoxic effects to its target cells need to be evaluated for additional Cr(VI) salts. Accordingly, we investigated the cytotoxicity and clastogenicity of barium chromate (BC) in a human lung cell culture model (WTHBF-6 cells). We found that BC induced concentration-dependent cytotoxicity in WTHBF-6 cells, with relative survival of 88%, 74%, 67%, 12%, 3%, and 0.1% after exposure to 0.01, 0.05, 0.1, 0.5, 1, and 5 μg/cm2 BC, respectively. Similarly, the amount of chromosomal damage also increased with concentration after a 24-h exposure. Specifically, 0.01, 0.05, 0.1, and 0.5 μg/cm2 BaCrO4 damaged 5%, 9%, 22%, and 49% of metaphase cells, with the total damage reaching 5, 10, 28, and 65 aberrations per 100 metaphases, respectively. Concentrations of 1 and 5 μg/cm2 BC induced a profound cell cycle delay, and no metaphases were observed. The spectrum of damage included chromatid and chromosome-type lesions consistent with mechanistic events associated with the activation of oncogenes and inactivation of tumor suppressor genes. Overall the data indicate that BC is cytotoxic and genotoxic to human lung cells. Environ. Mol. Mutagen. 42:274–278, 2003. © 2003 Wiley-Liss, Inc.
Milk Production Response of Dairy Cows Fed High-Moisture Grass Silage. I. Effect of Varying Levels of Hay and Concentrate

Abstract Varying levels of hay and concentrate were fed in conjunction with high-moisture grass silage ad libitum to 16 lactating cows, to determine the effects of these ration variables on milk production and composition. Feeding the higher level of concentrate (0.6 kg/kg 4% FCM over 8.16kg) resulted in the production of more 4% FCM (P Increasing the level of concentrate fed was more effective than increasing the level of hay for maintaining high dry-matter intake and in meeting the estimated TDN requirements of the cows. The TDN system of feed evaluation provided a reliable estimate of the relative nutritive value of these rations.
Reproductive response of caged adult velvetbean caterpillar and soybean looper to the presence of weeds

Greenhouse studies on the relationship of soybean looper, Pseudoplusia includens (Walker), moths to different nectar-producing plants resulted in greatest egg production from moths exposed to cotton. A similar experiment indicated an increase in egg production by the velvetbean caterpillar, Anticarsia gemmatalis (Hubner), when moths were exposed to increased densities of hemp sesbania, Sesbania exaltata (Raf.). In field cage experiments conducted, fecundity of both soybean looper and velvetbean caterpillar was significantly higher (P < 0.05) when exposed to soybean with weeds. Soybean looper moths had a mean of 163.3 and 86.7 eggs in ovaries when exposed to weedy and weed-free soybean, respectively. Ovaries of velvetbean caterpillar moths contained a mean of 107.5 and 27.2 eggs when exposed to weedy and weed-free soybean, respectively. Weed management strategies to minimize benefits to flower-feeding pests and to enhance natural enemies in cotton are discussed.
Effect of Inflammatory and Noninflammatory Stress on Plasma Ketone Bodies and Free Fatty Acids and on Glucagon and Insulin in Peripheral and Portal Blood

Inflammatory stress as characterized by infection withStreptococcus pneumoniae, administration of endotoxin, or the induction of a turpentine abscess is characterized by the inhibition of the ketosis associated with fasting and a decline in the level of free fatty acids in the plasma. Moreover, rats subjected to these inflammatory stresses demonstrate a significant rise in peripheral and portal insulin and glucagon. Rats subjected to noninflammatory stresses, screen-restraint, or noninvasive femoral fracture did not demonstrate the inhibition of ketosis but did show a decrease in plasma free fatty acids. The noninflammatory stresses did not show an abnormal elevation of plasma or portal insulin or glucagon.
The Growth Pattern of the Cornish Fowl

Abstract THE increased interest in poultry meat production has resulted in a corresponding interest in the Cornish breed. This breed is of particular interest because it has been shown to possess unique fleshing qualities. Information concerning the growth pattern which might make possible more efficient selection of breeding birds at an early age would be worthwhile. This paper is a portion of a more complete correlative study of five criteria of growth. In recent years, it has come to be recognized that weight, taken alone, is not entirely satisfactory as the measure of growth. Five primary growth criteria, namely body weight, shank length, anterior body depth, length of sternum and breast width were used in this study. These data, in a sense, provide information on the speed of growth processes concerned with mass, volume and length of the long bones. In addition the breast width study furnishes a measure of the . . .
Reduced seasonality of Holocene climate and pervasive mixing of Holocene marine section: Northeastern Gulf of Mexico shelf

The large porcelaneous foraminifers Cyclorbiculina compressa, Parasorites orbitolitoides , and Peneroplis proteus are conspicuous in death assemblages from Holocene marine sediments of the Alabama and Florida panhandle shelf. The species inhabited the northeastern Gulf of Mexico in the Holocene (ca. 6.4–1.9 ka) but do not live in the region today. These foraminifers require warm, clear waters, and thus are important paleoclimatic and paleoenvironmental indicators. They apparently were derived from sublittoral seagrass habitats and indicate reduced seasonality in the region during the middle to late Holocene. In addition, a mixed foraminiferal fauna, a hydrodynamically reworked macrofaunal assemblage, and stratigraphic disorder in foraminiferal 14 C dates indicate extensive reworking of the entire Holocene marine transgressive package. Evidence that mollusks are indigenous but large foraminifers are transported supports the generalization that out-of-habitat transport of macrofauna is negligible in most marine settings.
An Upper Limit for Atomic Orbital Electron Ejection Accompanying K-Capture in Fe 55

An upper limit has been determined for the number of atomic orbital electrons ejected during the decay of ${\mathrm{Fe}}^{55}$ by orbital capture. From cloud-chamber observations it is concluded that less than 0.6\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}6}$ electron are ejected per disintegration with energies in the range 30 kev to 205 kev. The theoretical prediction gives the order of ${10}^{\ensuremath{-}6}$ electron per disintegration for the frequency of the process in the energy range studied.
Chromatographic Method Validation: A Review of Current Practices and Procedures. Part II. Guidelines for Primary Validation Parameters

Abstract Validation of analytical methodologies is an important aspect of their development/utilization and is widely required in support of product registration applications. In this manuscript, definitions, procedures and acceptance criteria which appear in the pharmaceutical literature are summarized for the more commonly encountered validation parameters. Parameters examined include accuracy, precision, specificity, linearity and sensitivity limits. †Previously published in J. Liq. Chrom. & Rel. Technol., 19(12), 1873-1891 (1996).
Development of an Open-source Space or Airborne Multi-wavelength LIDAR Modeling Framework and Accompanying Programs with Application to the ASCENDS Mission

Lidar modeling framework to quantitatively evaluate the performance and error contributions in projected space or airborne hard-target lidar measurements is described. Application to the ASCENDS mission CO2 and O2 sensing is presented.
Engagement of Neural Circuits Underlying 2D Spatial Navigation in a Rodent Virtual Reality System

Summary Virtual reality (VR) enables precise control of an animal's environment and otherwise impossible experimental manipulations. Neural activity in rodents has been studied on virtual 1D tracks. However, 2D navigation imposes additional requirements, such as the processing of head direction and environment boundaries, and it is unknown whether the neural circuits underlying 2D representations can be sufficiently engaged in VR. We implemented a VR setup for rats, including software and large-scale electrophysiology, that supports 2D navigation by allowing rotation and walking in any direction. The entorhinal-hippocampal circuit, including place, head direction, and grid cells, showed 2D activity patterns similar to those in the real world. Furthermore, border cells were observed, and hippocampal remapping was driven by environment shape, suggesting functional processing of virtual boundaries. These results illustrate that 2D spatial representations can be engaged by visual and rotational vestibular stimuli alone and suggest a novel VR tool for studying rat navigation.
Review of: effect of vitamin D supplementation on progression of knee pain and cartilage volume loss in patients with symptomatic osteoarthritis.

Practice PearlOsteoarthritis is a widespread and significant disorder. Correction of vitamin D deficiency in patients with significant osteoarthritis of the knee did not result in improvement of pain symptoms or in preservation of cartilage in the knee space.
A model atmosphere analysis of the binary 112 Herculis

Double-lined spectra have been obtained at 2 A/mm for the Mn star 112 Herculis AB. The components are shown to be a B6.5V star and A2V star. Hydrogen-line-blanketed models are used to calculate atmospheric abundances. The best models appear to beT e=13500 K, logg=4.0, ξ T =2.5 km/sec for the primary; andT e=10000K, logg=4.2, ξ T =6 km/sec for the secondary. Both stars appear to have the same abundances. Helium, carbon, magnesium, aluminum, silicon, calcium, vanadium, and nickel appear to be considerably underabundant; phosphorus, scandium, titanium, manganese, iron, gallium, and mercury considerably overabundant; and chromium, strontium, and zirconium normal in abundance.
Output modeling: abc's of output analysis

We present a brief overview of several of the basic output analysis techniques for evaluating stochastic dynamic simulations. This tutorial is intended for those with little previous exposure to the topic, for those in need of a refresher course, and especially for those who have never heard of output analysis. We discuss the reasons why simulation output analysis differs from that taught in basic statistics courses and point out how to avoid common pitfalls that may lead to erroneous results and faulty conclusions.
Prostaglandin F2 alpha mediates ovarian sterol carrier protein-2 expression during luteolysis

In the corpus luteum, prostaglandin F2 alpha (PGF2 alpha) appears to be a physiological agent with both antisteroidogenic and luteolytic actions. It is hypothesized that the antisteroidogenic action of PGF2 alpha acts through altered transport of cholesterol to the mitochondrial cytochrome P450 side-chain cleavage enzyme (P450scc). However, the effect of PGF2 alpha on the expression of the putative cholesterol transport protein, sterol carrier protein-2 (SCP2; 13.2 kilodaltons), has not been examined. In this study, the decline in serum progesterone after PGF2 alpha injection was examined in parallel with altered ovarian SCP2, P450scc, and 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) protein and messenger RNA (mRNA) levels. Rats (28 days old) were treated with 8 IU PMSG to induce follicular development and ovulation. Ten days after ovulation, animals were treated with PGF2 alpha (single or multiple injections; 100-250 micrograms each) or left untreated. Ovarian SCP2, P450scc, and 3 beta HSD protein and mRNA levels were examined 0 (time zero), 4, and 8 h post-PGF2 alpha treatment using Western and Northern blot analysis. SCP2 mRNA levels were also examined using a highly sensitive ribonuclease protection assay that detects a 429-base pair SCP2-mRNA specific sequence. The results indicate that serum progesterone was significantly reduced 4 and 8 h after PGF2 alpha injections (P < 0.001; n = 6/time point). The decline in progesterone paralleled a 50-60% reduction in 3 beta HSD protein and mRNA levels by 4 h post-PGF2 alpha. Protein and mRNA levels for 3 beta HSD returned to control values by 8 h post-PGF2 alpha treatment. P450scc expression was also reduced at 4 h (44-54%), but by 8 h, both protein and mRNA levels had increased above the normal control levels (P < 0.02). In contrast, the 0.8-kilobase SCP2-specific mRNA transcript was reduced to 50% and 80% of the pre-PGF2 alpha treatment level at 4 and 8 h, respectively (P < 0.01). SCP2 ribonuclease protection assay analysis also indicated that SCP2 mRNA levels were reduced 65% (P < 0.03) and 85% (P < 0.01) by 4 and 8 h post-PGF2 alpha treatment compared to those in time zero ovarian tissue. Consistent with the loss of SCP2 mRNA expression, Western blot analysis indicated that a 15-kilodalton SCP2-immunoreactive protein (presumably the pro-SCP2 form) was significantly reduced or absent in the PGF2 alpha treated animals (P < 0.04).(ABSTRACT TRUNCATED AT 400 WORDS)
Effects of Vitreoscilla hemoglobin on the 2,4-dinitrotoluene (2,4-DNT) dioxygenase activity of Burkholderia and on 2,4-DNT degradation in two-phase bioreactors

Expression of vgb, encoding Vitreoscilla hemoglobin (VHb), in Burkholderia strain YV1 was previously shown to improve cell growth and enhance 2,4-dinitrotoluene (2,4-DNT) degradation compared with control strain DNT, especially under hypoxic conditions. In the work reported here, the ratio of 2,4-DNT degraded to oxygen uptake was approximately 5-fold larger for strain YV1 than for strain DNT. The addition of purified VHb to cytosolic fractions of strain DNT increased 2,4-DNT degradation 1.5-fold, compared with 1.1-fold for control bovine Hb, but increased the 2,4-DNT degradation 2.7-fold when added to partially purified 2,4-DNT dioxygenase, compared with 1.3-fold for bovine Hb. This suggests a direct transfer of oxygen from VHb to the oxygenase. In a bioreactor at high 2,4-DNT concentration (using 100 ml oleyl alcohol containing 2 g 2,4-DNT as the second phase) with 1.5 l culture, both strains could remove 0.8 g 2,4-DNT by 120 h; and, under the same conditions in a fed-batch reactor, the degradation increased to 1 g for strain YV1 but not for strain DNT.
Homeostatic Cytokines Induce CD4 Downregulation in African Green Monkeys Independently of Antigen Exposure To Generate Simian Immunodeficiency Virus-Resistant CD8αα T Cells

African green monkeys (AGMs; genus Chlorocebus) are a natural host of simian immunodeficiency virus (SIVAGM). As they do not develop simian AIDS, there is great interest in understanding how this species has evolved to avoid immunodeficiency. Adult African green monkeys naturally have low numbers of CD4 T cells and a large population of major histocompatibility complex class II-restricted CD8αdim T cells that are generated through CD4 downregulation in CD4+ T cells. Mechanisms that drive this process of CD4 downregulation are unknown. Here, we show that juvenile AGMs accelerate CD4-to-CD8αα conversion upon SIV infection and avoid progression to AIDS. The CD4 downregulation induced by SIV infection is not limited to SIV-specific T cells, and vaccination of an adult AGM who had a negligible number of CD4 T cells demonstrated that CD4 downregulation can occur without antigenic exposure. Finally, we show that the T cell homeostatic cytokines interleukin-2 (IL-2), IL-7, and IL-15 can induce CD4 downregulation in vitro. These data identify a mechanism that allows AGMs to generate a large, diverse population of T cells that perform CD4 T cell functions but are resistant to SIV infection. A better understanding of this mechanism may allow the development of treatments to induce protective CD4 downregulation in humans. IMPORTANCE Many African primate species are naturally infected with SIV. African green monkeys, one natural host species, avoid simian AIDS by creating a population of T cells that lack CD4, the human immunodeficiency virus/SIV receptor; therefore, they are resistant to infection. However, these T cells maintain properties of CD4+ T cells even after receptor downregulation and preserve immune function. Here, we show that juvenile AGMs, who have not undergone extensive CD4 downregulation, accelerate this process upon SIV infection. Furthermore, we show that in vivo, CD4 downregulation does not occur exclusively in antigen-experienced T cells. Finally, we show that the cytokines IL-2, IL-7, and IL-15, which induce homeostatic T cell proliferation, lead to CD4 downregulation in vitro; therefore, they can provide signals that lead to antigen-independent CD4 downregulation. These results suggest that if a similar process of CD4 downregulation could be induced in humans, it could provide a cure for AIDS.
Self-Diffusion in Potassium

The self-diffusion of $^{42}\mathrm{K}$ in potassium has been measured over the temperature range - 52.2 \ifmmode\pm\else\textpm\fi{} + 61.8\ifmmode^\circ\else\textdegree\fi{}C. The temperature dependence of the diffusion coefficient can be described by $D=0.16\ifmmode\pm\else\textpm\fi{}0.01 {e}^{\ensuremath{-}\frac{(9360\ifmmode\pm\else\textpm\fi{}50)}{\mathrm{RT}}}$. However the deviations of the individual points from this Arrhenius line suggest that diffusion could be occurring by two mechanisms.
Models for papilloma multiplicity and regression : applications to transgenic mouse studies

In cancer studies that use transgenic or knockout mice, skin tumour counts are recorded over time to measure tumorigenicity. In these studies cancer biologists are interested in the effect of endogenous and/or exogenous factors on papilloma onset, multiplicity and regression. In this paper an analysis of data from a study conducted by the National Institute of Environmental Health Sciences on the effect of genetic factors on skin tumorigenesis is presented. Papilloma multiplicity and regression are modelled by using Bernoulli, Poisson and binomial latent variables, each of which can depend on covariates and previous outcomes. An EM algorithm is proposed for parameter estimation, and generalized estimating equations adjust for extra dependence between outcomes within individual animals. A Cox proportional hazards model is used to describe covariate effects on the onset of tumours.
AFM Investigations of Chemical-Mechanical Processes on Silicon(100) Surfaces

Atomic force microscopy (AFM) was used to examine chemical-mechanical processes on Si (100) surfaces. Places where the underlying silicon was exposed etched in basic solution, producing structures 100 nm or less in size. Etching occurs only in the presence of combined mechanical and chemical effects. By performing AFM in basic solution, the entire etching process could be observed directly. High-force scans were used to remove oxide and initiate etching in selected locations, followed by low-force scans which imaged the etching process. Although roughness initially increased during etching, the final surfaces were smooth. The etching was measured for different applied loads, numbers of scans, concentrations of the etching solution, and time. The oxide layer was extremely sensitive to applied stress, and even very light scanning caused the oxide layer to dissolve more rapidly. Once the oxide layer was removed, chemical etching proceeded with or without AFM scanning, but if AFM scanning was continued additional material was removed, probably by a tribochemical mechanism on pure Si.
Trajectories of Dehydroepiandrosterone Sulfate Predict Mortality in Older Adults: The Cardiovascular Health Study

MAINTENANCE of homeostasis is a fundamental mechanism for survival. With increasing age, there is a decreased ability to handle threats to homeostasis, though the rate at which this happens at the individual level varies greatly (1). At present, there is no established way to measure one’s ability to maintain homeostasis (2). Determination of hormonal status may provide insight because metabolic regulation is important to maintaining homeostasis. Dehydroepiandrosterone sulfate (DHEAS) is the circulating sulfated conjugate of dehydroepiandrosterone (DHEA), a steroid synthesized mainly in the zona reticularis of the adrenal gland. This portion of the adrenal gland is large in fetal life and shrinks progressively with age after puberty. DHEA has no known direct hormonal activity in humans but may serve as a precursor for androgenic and estrogenic steroids. Circulating levels of DHEAS are lower in older than in younger people, resulting in mean levels at age 65 that are less than a fifth of mean levels at age 20 (3,4). This finding has led to speculation that lower levels of DHEAS in older people contribute to the aging process and has driven widespread over-the-counter DHEA supplement use. However, DHEA replacement studies in older adults have failed to support the role for DHEAS as an antiaging hormone (5). Furthermore, not all individuals experience a steady decline in DHEAS levels with age (6–9). Beyond the absolute DHEAS level, the way that a DHEAS level changes over time may provide insight into an individual and his/her ability to maintain homeostasis and thereby the way that they age. We sought to use analysis of trajectories of DHEAS to examine the biology of aging at the population level. We hypothesized that, irrespective of the actual level of DHEAS, older individuals with stability in DHEAS levels over time would have better survival than those with significant deviations, such as a steep decline or extreme variability. We also hypothesized that there would be differences between men and women in the effects of these deviations because of sex-specific differences in the underlying hormonal milieu.
Air-stable solution-deposited chalcopyrite CuIn 1−x Ga x Se 2 thin film solar cells

The conversion efficiency of CIGS solar cells has reached up to a 20.3% record value [1]. It is desirable to reduce the CIGS cell cost by lowering down the manufacturing cost to enable its broader applications in the market place. Solution-based deposition offers an opportunity to fabricate CIGS thin film solar cells at a more competitive cost compared to the conventional vacuum-based process. Recently, several non-vacuum technologies, including Inkjet printing [2], electroplating [3], hydrazine [4] and nanoparticles [5], have shown great potentials to achieve comparable results with vacuum technologies. However, there are still considerable drawbacks which impede their application in a wider market field, such as the toxicity and flammability of dissolving solvents, tedious preparation process of precursor inks and fatal residuals left from organic compounds. Therefore, a versatile and controllable ink formula and an affordable deposition process are desired to fulfill the low-cost and safety requirements. In order to achieve decent conversion efficiency, the ideal chalcopyrite CIGS absorber layer should be also free of secondary phases and contaminations including binary Cu 2−x Se phase, amorphous carbon and residual from solution deposition. Herein, a novel solution-based process using low cost precursors that is capable of achieving these goals is reported.
Palliative care advocacy in the United States: are there lessons for geriatric psychiatry?

P care in the United States began less than four decades ago and has grown from “a small rebellion”1 into a fully recognized medical subspecialty.2–4 The American Board of Medical of Medical Specialties (ABMS) reported in 2008 that 1,266 physicians passed the first subspecialty certification examination offered in hospice and palliative medicine.5 Ten different subspecialties, including psychiatry, sponsored this subspecialty certification.5 By comparison, 490 physicians achieved certification with added qualification (CAQ) for geriatric psychiatry for the first time in 1991, and this CAQ evolved into subspecialty certification by 1997.6–8 Beside achieving subspecialty recognition, geriatric psychiatry and palliative care share other key features. Both fields offer specialty care to an underserved, but growing and aging, population.7 Both require cognitive skills for providing evaluation and management services that customarily receive lower reimbursement than specialties that emphasize procedures.7 Fellowship training programs for palliative care and geriatric psychiatry share overlapping core competencies and curriculum elements,9,10 and both fields recruit trainees from a similar pool of candidates.7 Similarly, palliative care and geriatric psychiatry seek several common goals, such as assuring access to underserved patients, growing workforces in a competitive environment, and protecting their own long-term viability.
Learning To Learn Through Observation

Observational learning is theoretically conceptualized as a skill that can be developed along a learning hierarchy from acquisition and fluency to generalization of initiative behavior. This review characterizes these levels of observational learning and details differential teaching strategies that have been endeavored at each level. The hierarchy can assist the teacher in determining the status of a student's observational learning skills, in recognizing essential instructional components in planning, and in organizing instruction to systematically enhance the student's ability to acquire more complex observational skills.
Can the cerebral metabolic rate of oxygen be estimated with near-infrared spectroscopy?

We have measured the changes in oxy-haemoglobin and deoxy-haemoglobin in the adult human brain during a brief finger tapping exercise using near-infrared spectroscopy (NIRS). The cerebral metabolic rate of oxygen (CMRO2) can be estimated from these NIRS data provided certain model assumptions. The change in CMRO2 is related to changes in the total haemoglobin concentration, deoxy-haemoglobin concentration and blood flow. As NIRS does not provide a measure of dynamic changes in blood flow during brain activation, we relied on aW indkessel model that relates dynamic blood volume and flow changes, which has been used previously for estimating CMRO2 from functional magnetic resonance imaging (fMRI) data. Because of the partial volume effect we are unable to quantify the absolute changes in the local brain haemoglobin concentrations with NIRS and thus are unable to obtain an estimate of the absolute CMRO2 change. An absolute estimate is also confounded by uncertainty in the flow–volume relationship. However, the ratio of the flow change to the CMRO2 change is relatively insensitive to these uncertainties. Fo rt he finger tapping task, we estimate a most probable flow–consumption ratio ranging from 1.5 to 3 in agreement with previous findings presented in the literature, although we cannot exclude the possibility that there is no CMRO2 change. The large range in the ratio arises from the large number of model parameters that must be estimated from the data. A more precise estimate of the flow–consumption ratio will require better estimates of the model parameters or flow information, as can be provided by combining NIRS with fMRI.
Transfer and Descent: Some Recent Results

A basic tool for studying the transfer of representations is the dual transfer of orbital integrals. In this paper we report on some recent results for orbital integrals and, in particular, on a descent theorem [LS3].
The Treatment of Minimal Change Disease in Adults

Minimal change disease (MCD) is the etiology of 10%–25% of cases of nephrotic syndrome in adults. The mainstay of treatment for adult MCD, oral gucocorticoids, is based on two randomized controlled trials and extensive observational data in adults, and this treatment leads to remission in over 80% of cases. Relapses are common, and some patients become steroid-resistant (SR), steroid-dependent (SD), or frequently relapsing (FR). The data guiding the treatment of these patients are limited. Here, we review MCD in adults with particular focus on the evidence for immunosuppressive therapy in these patients.
Note-On the Optimality of Integer Lot Size Ratios in Economic Lot Size Determination in Multi-Stage Assembly Systems

The proof of a well known theorem by Crowston and Wagner in Crowston, Wagner, and Williams Crowston, W. B., M. H. Wagner, J. F., Williams. 1973. Economic lot size determination in multi-stage assembly systems. Management Sci.19 5, January 517-527. is shown here to be defective. According to this theorem, an optimal solution to the batch size determination problem for multi-echelon production/inventory assembly structures is characterized by a set of lot sizes, such that the lot size at each stage must be an integer multiple of the lot size at its successor stage. The theorem has been said to apply to uncapacitated assembly systems having constant final product demand over an infinite horizon, with no backlogs or lost sales permitted, where lot sizes must be rational numbers and time invariant. While the theorem supposedly applied to the case of both finite production rates and infinite production rates, the proof dealt only with the case of instantaneous production. Also, the proof implicitly assumed that lots were processed at any given stage only after unchanging spans of time. In this paper we show that with or without this implicit assumption, the theorem does hold true for the special case of instantaneous processing in two-level assembly systems; that is, configurations where there is only one successor stage in the entire system. However, we also show by counterexample that without this implicit assumption, the theorem is invalid for more general assembly structures. Furthermore, in the appendix of this paper we show that the proof is defective at the point where Crowston and Wagner extend their results for two-level systems to more general assembly systems. Thus it is an open question whether or not the theorem is valid for all assembly structures when processing at any given stage must occur only after unchanging spans of time.
Comparative Law and the Interpretation of Contractual Intent (Réflexions Sur L’Interprétation De La Volonté Des Contractants En Droit Comparé)

This paper uses a comparative approach to analyze legal rules for interpreting contracts. It concludes that the rules of common law systems, continental law systems and international law have converged so that all adopt similar methods for the interpretation of contracts. It also demonstrates that the traditional distinction between objective and subjective methods of interpretation appears to have been discarded in favor of a more pragmatic approach, which takes into account the stakes of the contract, whether of an economic nature or not.
Micro-compression: a novel technique for the nondestructive assessment of local bone failure

Many bones within the axial and appendicular skeleton are subjected to repetitive, cyclic loading during the course of ordinary daily activities. If this repetitive loading is of sufficient magnitude or duration, fatigue failure of the bone tissue may result. In clinical orthopedics, trabecular fatigue fractures are observed as compressive stress fractures in the proximal femur, vertebrae, calcaneus and tibia, and are often preceded by buckling and bending of microstructural elements. However, the relative importance of bone density and architecture in the etiology of these fractures is poorly understood. The aim of the study was to investigate failure mechanisms of 3D trabecular bone using micro-computed tomography (\muCT). Because of its nondestructive nature, \muCT represents an ideal approach for performing not only static measurements of bone architecture but also dynamic measurements of failure initiation and propagation as well as damage accumulation. For the purpose of the study, a novel micro-compression device was devised to measure loaded trabecular bone specimens directly in a micro-tomographic system. The measurement window in the device was made of a radiolucent, highly stiff plastic to enable X-rays to penetrate the material. The micro-compressor has an outer diameter of 19 mm and a total length of 65 mm. The internal load chamber fits wet or dry bone specimens with maximal diameters of 9 mm and maximal lengths of 22 mm. For the actual measurement, first, the unloaded bone is measured in the \muCT. Second, a load-displacement curve is recorded where the load is measured with an integrated mini-button load cell and the displacement is computed directly from the \muCT scout-view. For each load case, a 3D snap-shot of the structure under load is taken providing 34 \mum nominal resolution. Initial measurements included specimens from bovine tibiae and whale spine to investigate the influence of the structure type on the failure mechanism. In a rod-like type of architecture as seen in the whale spine, structural failure was described by an initial buckling and bending of structural elements followed by a collapse of the overloaded trabeculae. In the more plate-like bovine tibial architecture, buckling and bending could not be observed. Failure rather seemed to occur instantaneously. In conclusion, micro-compression in combination with 3D \muCT allows visualization of failure initiation and propagation and monitoring of damage accumulation in a nondestructive way. We expect these findings to improve our understanding of the relative importance of density, architecture and load in the etiology of spontaneous fractures of the hip and the spine. Eventually, this improved understanding may lead to more successful approaches to the prevention of age-related fractures.
Training and optimization of operating parameters for flash LADAR cameras

Flash LADAR cameras based on continuous-wave, time-of-flight range measurement deliver fast 3D imaging for robot applications including mapping, localization, obstacle detection and object recognition. The accuracy of the range values produced depends on characteristics of the scene as well as dynamically adjustable operating parameters of the cameras. In order to optimally set these parameters during camera operation we have devised and implemented an optimization algorithm in a modular, extensible architecture for real-time applications including robot control. The approach uses two components: offline nonlinear optimization to minimize the range error for a training set of simple scenes followed by an online, real-time algorithm to reference the training data and set camera parameters. We quantify the effectiveness of our approach and highlight topics of interest for future research.
Behavioral synthesis in CADET, a case-based design tool

The authors present an approach to the conceptual design of hydromechanical systems using a case base of previous designs. The authors outline an approach to transforming the given specifications in a behavior-preserving manner, so as to enable retrieval, and subsequent synthesis of relevant component cases and pieces of cases. The investigation of the behavior preserving transformational strategies is conducted within a framework of a case based reasoning methodology for mechanical design and has been implemented in the CADET (case design tool) system. The process consists of applying behavior-preserving transformations, based on qualitative calculus, to an abstract description of the desired behavior of the device until a description is found that closely corresponds to some collection of relevant cases. >
Some Statistical Perspectives of Growth Models in Health Care Plans

Growth (and wear) curve models, having genesis in epidemiology and system biology, have cropped up in every walk of life and science. In statistics, such growth curve models have led to an evolution of multivariate analysis with better performance characteristics and enhanced scope of applications in many interdisciplinary field of research. Recent advances in bioinformatics and genomic science have opened the Pandora’s box with high-dimensional data models, often with relatively smaller sample sizes. Growth curve models are especially useful in such contexts. There are also other areas where growth curve model-based analyses are in high demand. In this vein, the scope and perspectives of growth models are appraised with special emphasis on some health care and health study plans.
Assessing and Measuring the Fiscal Heath of Local Governments Focus on Chicago Suburban Municipalities

This study presents a framework for assessing the financial condition and fiscal health of municipal governments, develops indices for some dimensions of the framework, and applies the indices to 264 suburban municipalities in the Chicago metropolitan region. The framework is based on a systems view of local government financial condition. It shows that fiscal health is a complex and multidimensional concept with varying time frames. Furthermore, the dimensions are related but often in indirect or nonlinear ways, indicating they must be measured separately rather than combined into a comprehensive indicator of fiscal health. Indices developed here for targeted dimensions of the framework are assessed and compared to alternative indicators of fiscal health developed by others in the field.
On the design and evaluation of the PDA-based research platform for electric and acoustic stimulation

The aim of the paper is to describe the bimodal (combining electrical stimulation via the implant with acoustic stimulation via hearing aids) design of the PDA-based research platform and present results from a short-term evaluation with five bimodal cochlear implant users. The evolution of the PDA platform has been reported earlier in terms of development and its potential in various experiments. This paper focuses on the evaluation of the platform with bimodal users in terms of speech intelligibility in quiet, 10dB and 5dB SNR conditions and compares the results with the users' own clinical processor. The results of this clinical trial will encourage researchers in this area to use the platform in their future studies as it provides unparalleled flexibility along with a large suite of applications to conduct a wide variety of experiments for electric-only and combined electric and acoustic stimulation (EAS) for long-term chronic studies with great ease.