cssi/SciSciGPT-SciSciNet huggingface dataset:
Modulation of the exciton lifetime of j-aggregates on metal nanoparticles and nanoparticle arrays explored through ultrafast spectroscopy and near-field optical microscopy

Illumination of metal nanoparticles at the plasmon resonance produces enhanced evanescent fields on the nanoparticles’ surfaces. The unusual strength of the field make it a target for exploring photoinduced phenomena at the nanoscale, if efficient functionalization or coating of the nanoparticle surface with appropriate chromophores is possible. One direction is to use cyanine dyes that form monolayers of J-aggregates on the surface of noble metal nanoparticle colloids. The unique, collective electronic properties of J-aggregates produce excitons with enormous extinction coefficients that are of interest for their efficient energy transfer, electron transfer, and nonlinear optical properties. In that vein, we report our results on time-resolved spectroscopy and near-field scanning optical microscopy (NSOM) of J-aggregate exciton dynamics on Ag and Au nanoparticle colloids. Ultrafast transient absorption studies show that J-aggregate exciton lifetimes on Ag nanoparticles are much longer than on Au nanoparticles, with a 300 ps lifetime that is two orders of magnitude longer than the electronic processes in the nanoparticles themselves. Complementary NSOM studies of the colloids show that fluorescence from the J-aggregates on the Ag nanoparticles is induced by the scanning probe. These results may be significant for improving the nanophotonic performance of hybrid materials for nanoscale applications.
FUNCTIONAL HYPOPARATHYROIDISM AND PARATHYROID HORMONE END‐ORGAN RESISTANCE IN HUMAN MAGNESIUM DEFICIENCY

Hypocalcaemia is a well-recognized manifestation of magnesium deficiency. We have studied seventeen patients with this syndrome in an attempt to determine the pathogenesis of the hypocalcaemia. Mean initial serum calcium concentration was 5-6 mg/dl and mean initial serum magnesium concentration was 0-75 mg/dl. Serum immunoreactive parathyroid hormone (IPTH) was measured in sixteen patients in the untreated state. Despite severe hypocalcaemia, serum IPTH was either undetectable (less than 150 pg/ml) or normal (less than 550 pg/ml) in all but two patients. Serial measurements made during the initial 4 days of magnesium therapy in four patients showed an increase in serum IPTH within 24h, but a delayed increase in serum calcium, which required approximately 4 days to reach normal values. The effect of the rapid normalization of serum magnesium on serum IPTH and serum calcium concentration was studied in three patients. Within 1 min after 144-300 mg of elemental magnesium was administered i.v., serum IPTH had risen from undetectable to 3600 pg/ml and 1725 pg/ml in two patients and from 425 pg/ml to 937 pg/ml in the third. Serum calcium concentrations were unchanged after 30-60 min. These data provide evidence for impaired parathyroid gland function in most of the magnesium deficient patients. The rapidity with which serum IPTH rose in response to magnesium therapy indicates that this may reflect a defect in parathyroid hormone (PTH) secretion rather than its biosynthesis. The failure of serum calcium concentration to increase during the initial days of magnesium repletion, at a time when serum IPTH concentrations were normal or elevated, suggests end-organ resistance to PTH in these patients. The renal response to PTH was examined in two magnesium deficient patients by measurement of urinary cyclic AMP excretion following administration of parathyroid extract. In both patients there was a minimal increase in urinary cyclic AMP concentrations. In contrast, when the hepatic response to glucagon was tested on the same patients by measurement of plasma cyclic AMP concentrations following administration of glucagon, normal increases were observed. These results suggest that adenylate cyclase systems of various organs may be affected differentially by a state of magnesium deficiency. It is suggested that magnesium deficiency may result in defective cyclic AMP generation in the parathyroid glands and in the PTH target organs. This could be the principal mechanism operative in both impaired PTH secretion and end-organ resistance to PTH which together contribute to the development of hypocalcaemia.
Influence of Carbon Group Substituents on Bond Shift and Electrochemical Reduction of Cyclooctatetraene

The free energies of activation for bond shift in the carbon group substituted cyclooctatetraenes (COT−M(CH3)3) in THF-d8 at 298 K have been determined to be 16.4, 16.2, 16.2, and 18.1 kcal/mol for M = Si, Ge, Sn, and C, respectively, and 15.6 kcal/mol for CH3−COT. These data permit an interpretation of the previously reported opposite orders for the ease of the first and second electrochemical reductions in the Si, Ge, and Sn compounds. It is postulated that the order of the first reduction potential is controlled by a decrease in overlap between the substituent and the ring π orbitals in the order Si > Ge > Sn, whereas the second reduction potential is controlled by the energy gap between the symmetric π HOMO of the COT radical anion and an interacting substituent σ* orbital of π symmetry (eσ*π − eπ), which increases in the order Sn < Ge < Si. HF/3-21G molecular orbital calculations indicate that the high barrier for t-Bu−COT primarily reflects steric effects in the transition state.
Efferent systems of the rabbit visual cortex: Laminar distribution of the cells of origin, axonal conduction velocities, and identification of axonal branches

Several efferent systems of visual area I in Dutch rabbits were studied with anatomical (horseradish peroxidase) and physiological (antidromic) methods. Anatomical studies provided information regarding the laminar origin of the projections to the contralateral hemisphere, visual area II, the dorsal lateral geniculate nucleus, and the superior colliculus. Physiological studies provided information regarding conduction velocities and multiple destinations of efferent axons. Both the callosal projection and the projection to V-II were shown to originate primarily in layer II-III. However, approximately 10-20% of the callosal projection and 20–40% of the projection to V-II originated in layers IV and V. In contrast, the projection to the dorsal lateral geniculate nucleus originated nearly exclusively in layer VI, while corticotectal neurons occurred primarily in layer V. A significant number of corticotectal neurons were, however, found in layer IV. Thus, the above efferent systems were found to differ in their principal laminar origin and in the diffuseness of that origin. The origins of corticocortical projections were considerably more diffuse than those of corticofugal projections. In addition to differences in laminar origin, efferent systems also differed significantly in the conduction velocities of their axons. The projection to visual area II and to the lateral geniculate nucleus consisted primarily of very slowly conducting axons, while the projection to the superior colliculus was fast conducting. The callosal projection consisted of both slow and fast conducting axons. Finally, the question of branching of V-I efferent axons was addressed. Although the laminar origin of the projections to the contralateral hemisphere and to visual area II overlapped considerably, none of these corticocortical axons could be shown to project to both locations or to a subcortical destination. In contrast, approximately one-third of corticotectal axons were shown to project a collateral into the thalamus. Although the destination of this collateral is unclear, it is medial to the lateral geniculate nucleus and may be the pulvinar.
Data consistency in a multiprocessor system with ‘store in’ cache concept

Abstract This paper addresses the problems of maintaining data consistency in a multiprocessor system with an embedded cache on each processor. Common system resources are used to achieve data integrity under any circumstances. Special attention is given to keep the overhead for cache cross interrogation low. In addition a ‘Store In’ cache concept is used to reduce the ‘Wait’ cycles for memory access. Therefore maximum performance of the PUs is achieved with the implemented concept.
Backscatter correction factor for megavoltage photon beam.

Purpose: For routine clinical dosimetry of photon beams, it is often necessary to know the minimum thickness of backscatter phantom material to ensure that full backscatter condition exists. Methods: In case of insufficient backscatter thickness, one can determine the backscatter correction factor,BCF(s,d,t), defined as the ratio of absorbed dose measured on the central-axis of a phantom with backscatter thickness of t to that with full backscatter for square field sizes and forward depth d. Measurements were performed in SAD geometry for 6 and 15 MV photon beams using a 0.125 cc thimble chamber for field sizes between 10 × 10 and 30 × 30 cm at depths between d max (1.5 cm for 6 MV and 3 cm for 15 MV) and 20 cm. Results: A convolution method was used to calculateBCF using Monte-Carlo simulated point-spread kernels generated for clinical photon beams for energies between Co-60 and 24 MV. The convolution calculation agrees with the experimental measurements to within 0.8% with the same physical trend. The value of BCF deviates more from 1 for lower energies and larger field sizes. According to our convolution calculation, the minimum BCF occurs at forward depth d max and 40 × 40 cm field size, 0.970 for 6 MV and 0.983 for 15 MV. Conclusions: The authors concluded that backscatter thickness is 6.0 cm for 6 MV and 4.0 cm for 15 MV for field size up to 10 × 10 cm whenBCF = 0.998. If 4 cm backscatter thickness is used, BCF is 0.997 and 0.983 for field size of 10 × 10 and 40 × 40 cm for 6 MV, and is 0.998 and 0.990 for 10 × 10 and 40 × 40 cm for 15 MV, respectively.
Atmospheric ducts can transport sound in two directions

When conditions are right, temperature gradients and fast jets of wind can help to establish atmospheric ducts—pathways in the atmosphere that promote the propagation of low-frequency acoustic waves (infrasound)—across long distances. Atmospheric ducts are part of the basis behind over-the-horizon radar, the source of some particularly clear mirages, and a channel through which sounds can travel relatively unperturbed across vast distances.
POST-NEONATAL MORTALITY IN RURAL INDIA: IMPLICATIONS OF AN ECONOMIC MODEL

In this paper we develop and test a theory of childhood mortality after the first month of life. Parents are assumed to have well-defined family size and sex composition objectives and to face severe budget constraints. In this set of circumstances, it is understandable that they will make allocative decisions that will affect the survival probabilities of children. These decisions and the environmental influences on mortality are the basic forces which determine whether a child will survive through the post-neonatal period. The model is tested with survey data from rural Uttar Pradesh, India. The results are consistent with the hypothetical framework discussed above. The burden of this pattern of choice is felt particularly strongly by female births.
Induced defenses of loblolly pine, Pinus taeda: potential impact on Dendroctonus frontalis within-tree mortality

Abstract Loblolly pine (Pinus taeda L.) produces an induced defensive hypersensitive response in inner bark colonized by the southern pine beetle, Dendroctonus frontalis Zimm. (Coleoptera: Scolytidae), and its associated fungi. Adult beetles forced to colonize the induced response tissue in a laboratory study constructed galleries that were the same length as adults boring in normal phloem. However, each female laid fewer eggs in the induced tissue. Larval and pupal mortality were also higher in this tissue when compared to surrounding phloem. Beetles colonizing trees in response to pheromone baits constructed less gallery and laid fewer eggs in induced tissue than in surrounding normal phloem. These results suggest that the lesions produced by the induced defense system in conifers may not only contain the growth of fungi inoculated into trees during the attack phase of beetle colonization, but may also affect survival of bark beetle progeny. RESUME Systemes de defense induits chez Pinus taeda: impact potentiel de la mortalite a l'interieur de l'arbre sur Dendroctonus frontalis Une reaction hypersensible de defense a ete induite dans les couches profondes de l'ecorce de P. taeda colonisee par D. frontalis et le champignon qui lui est associe. Au laboratoire, des adultes, contraints de coloniser les tissus ou une reaction hypersensible e ete induite, ont fore des galeries de měme longueur que celles creusees dans du phloeme sain. Cependant les femelles ont pondu moins d'oeufs dans les tissus induits; les mortalites larvaires et nymphales etaient aussi plus fortes dans ce tissu que dans le phloeme voisin. Les scolytes, ayant colonise les arbres apres attraction par des pieges a pheromones, forent moins de galeries et pondent moins d'oeufs dans le tissu induit que dans le phloeme sain voisin. Ces resultats suggerent que les lesions, provoquees par le systeme de defense induit des coniferes, peuvent non seulement limiter la croissance du champignon inocule dans l'arbre au cours de la colonisation des scolytes, mais aussi affecter la survie des descendants dans l'ecorce.
Mismatch repair gene expression defects contribute to microsatellite instability in ovarian carcinoma

BACKGROUND hMLH1, the human MutL homologue, has been linked to microsatellite instability (MSI) in gastrointestinal tumors. However, to the authors' knowledge, the role of hMLH1, the other mismatch repair genes (MMR), and MSI in ovarian carcinoma has not been well defined. The purpose of the current study was to determine the relation between MSI of ovarian carcinoma and MMR gene expression, hMLH1 and hMSH2 hypermethylation, and hMLH1 and hMSH2 null mutations. METHODS hMLH1 mRNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and amplification of cDNA using a housekeeping gene (glycerol 3-phosphate dehydrogenase) as a control for mRNA quality and quantity. Methylation-specific PCR (MS-PCR) was used to correlate methylation of the hMLH1 and hMSH2 CpG islands with mRNA expression status. Similar techniques were used to evaluate the concomitant expression of five other MMR: hMSH2, hMSH3, hMSH6, PMS1, and PMS2. Microsatellite instability was studied using the National Cancer Institute consensus markers (D2S123, D5S346, D17S250, BAT25, and BAT26) and NM23 as described previously. RESULTS One hundred twenty-five primary tumors were analyzed. High-frequency MSI (MSI-H) was found in 21 tumors (16.8%). hMLH1 mRNA was absent in 10 of these 21 tumors (47.6%). In each case, coordinated hypermethylation of both regions A and C of the promoter was identified. Microsatellite stable and low-frequency MSI tumors all were found to express not only hMLH1 but the other MMR genes as well (P < 0.001). Absence of expression of hMSH2 and the four other MMRs occurred in tumors with absent hMLH1 mRNA expression because of CpG island hypermethylation. No absence of expression of hMSH2, hMSH3, hMSH6, PMS1, or PMS2 was found to occur in tumors expressing hMLH1. None of the 11 MSI-H tumors without promoter hypermethylation demonstrated a null mutation in hMLH1 or hMSH2. CONCLUSIONS A molecular mechanism to explain > 50% of the MSI-H phenotype in ovarian carcinoma cases was demonstrated. MSI-H may occur because of MMR defects, especially hMLH1 promoter hypermethylation. Additional mechanisms are required to explain the balance between the cases of MSI-H as well as the phenomenon of MSI-L tumors. Cancer 2003. © 2003 American Cancer Society.
Improving Public Response to Disaster Warnings: A Discussion Panel

Stories about substantial human and property losses caused by natural disasters made headlines in 2011 throughout the U.S. and around the world. Many of these stories described problems with the disaster warnings themselves as well as with human responses to these warnings, both of which may have increased the number of casualties. Although human factors research has made significant contributions to the design of product warnings in general, studies focused specifically on disaster warnings and associated responses are sparse (Cooke & Winner, 2007). Furthermore, disseminating warnings and supplemental information to guide decision making by the general public is increasingly challenging due to the rapid adoption of heterogeneous mobile technologies, particularly those providing Internet access. These technologies facilitate access to even more information during these time-sensitive situations, but the information may not be presented in ways that support effective decision-making. In this panel, we will discuss opportunities for human factors research to improve the public's preparation and response to disaster warnings. Panelists will discuss their research on individual differences in warning design and response, training effects on warning response, social media and emergency communications, communication and coordination among ad hoc disaster response teams, and decision making by weather forecasters. From these discussions, we hope to identify research areas with high potential for short-term impact. Language: en
Head Start’s impact is contingent on alternative type of care in comparison group.

Using data (n = 3,790 with 2,119 in the 3-year-old cohort and 1,671 in the 4-year-old cohort) from 353 Head Start centers in the Head Start Impact Study, the only large-scale randomized experiment in Head Start history, this paper examined the impact of Head Start on children’s cognitive and parent-reported social-behavioral outcomes through first grade contingent on the child care arrangements used by children who were randomly assigned to the control group (i.e., parental care, relative/non-relative care, another Head Start program, or other center-based care). A principal score matching approach was adopted to identify children assigned to Head Start who were similar to children in the control group with a specific care arrangement. Overall, the results showed that the effects of Head Start varied substantially contingent on the alternative child care arrangements. Compared to children in parental care and relative/non-relative care, Head Start participants generally had better cognitive and parent-reported behavioral development, with some benefits of Head Start persisting through first grade; in contrast, few differences were found between Head Start and other center-based care. The results have implications regarding the children for whom Head Start is most beneficial as well as how well Head Start compares to other center-based programs.
Cholesterol Modification of Sonic Hedgehog Is Required for Long-Range Signaling Activity and Effective Modulation of Signaling by Ptc1

Sonic hedgehog (Shh) signaling from the posterior zone of polarizing activity (ZPA) is the primary determinant of anterior-posterior polarity in the vertebrate limb field. An active signal is produced by an autoprocessing reaction that covalently links cholesterol to the N-terminal signaling moiety (N-Shh(p)), tethering N-Shh(p) to the cell membrane. We have addressed the role played by this lipophilic modification in Shh-mediated patterning of mouse digits. Both the distribution and activity of N-Shh(p) indicate that N-Shh(p) acts directly over a few hundred microns. In contrast, N-Shh, a form that lacks cholesterol, retains similar biological activity to N-Shh(p), but signaling is posteriorly restricted. Thus, cholesterol modification is essential for the normal range of signaling. It also appears to be necessary for appropriate modulation of signaling by the Shh receptor, Ptc1.
Correlations between host-cell reactivation, ultraviolet reactivation and pyrimidine dimer excision in the DNA of bacteriophage λ☆

Abstract The relationship between the excision of pyrimidine dimers, host-cell reactivation and ultraviolet reactivation of phage λ has been investigated. From the kinetics of dimer excision and correlated biological effects the following conclusions are drawn. (1) Host-cell reactivation of phage λ involves the excision of pyrimidine dimers by host-cell enzymes. (2) Ultraviolet reactivation of λ does not involve enhancement of pyrimidine dimer excision. (3) In cells containing either irradiated λ DNA or irradiated bacterial DNA, host-cell enzymes preferentially excise dimers from host-cell DNA. By contrast, in irradiated cells infected with irradiated λ, dimers in λ DNA limit the excision of bacterial dimers better than the converse situation. These results suggest an unequal distribution of repair enzymes within the cell.
Effects of O2 Tension and Temperature during Light Uptake of 14CO2 on the Dark Release of 14CO2 by Excised C3 and C4 Leaves

A study was conducted on a C 4 ( Panicum maximum ) and a C 3 ( Panicum bisulcatum ) species to determine the nature of the dark release of 14 CO 2 with respect to its responses to changes in temperature and O 2 tension during light CO 2 uptake of 14 CO 2 . The total one minute uptake of 14 CO 2 increased with increased temperatures up to 30°C for both species at all O 2 tensions. The total release of 14 CO 2 during the first four minutes of dark by the C 4 species was 5 to 10 times greater than the C 3 species; however, there was no consistent pattern in the C 4 species as a function of temperature or O 2 tension. In contrast, the dark release by the C 3 species was similar to that of light uptake as a function of temperature or O 2 tension. The percentage of the one-minute 14 CO 2 fixation that was released as 14 CO 2 during the first four minutes of dark increased with O 2 tension for the three highest temperatures (20, 30, and 38°C) and remained, though reduced, after a 10-minute dark chase in 12 CO 2 for the C 3 species. It was concluded that: (a) the source of the dark CO 2 release in C 3 species is different from that of C 4 species; (b) the dark CO 2 release in C 3 species likely is derived from intermediates of photorespiration and is similar to the postillumination burst of CO 2 ; and (c) the source(s) of the dark CO 2 release in C 4 species is not photorespiration.
The progress and distribution of U.S. living standards, 1959–1995

Abstract In spite of sustained economic growth and official statistics showing sizable average income gains over the past twenty years, most Americans believe real incomes have declined. This paper examines trends in the level and distribution of U.S. incomes and wages between 1959 and 1995 in order to account for this surprising pessimism. Overall income growth slowed after the mid-1970s. In addition, high-income families have received a growing percentage of income gains, and many middle- and low- income families saw their incomes climb as a result of increases in breadwinners' employment rates and hours of work rather than hourly wage gains.
NUCLEAR MICROSCOPY AT LIVERMORE

The construction of a new Nuclear Microprobe at the Livermore multi-user 10 MV FN tandem Laboratory has recently been completed. The facility is primarily used for PIXE, PIGE and Proton energy loss tomography (PELT) in a broad range of multi-disciplinary sciences. Details of the new facility and current applications/programs are discussed.
Multigrid ADI algorithm for solving diffusion equations

A Multi-grid model using the ADI algorithm (called MADI) is presented to solve the diffusion equation for medical applications and instrumentation development. Nesting multiple blocks of different grid sizes are used in the simulation to save both memory and time. MADI uses the computation results on a coarse grid scheme to provide an approximation of dynamic boundary conditions block-by-block toward the area of interest with finest grid. The precision of MADI is compared with and kept the same as the case of globally uniform finest grid simulation. Algorithm error bound is analyzed by matrix theory. As a conclusion, the thickness of the boundary area and the block width of the finest-grid center block determine the precision. The algorithm is also shown to achieve convergence with only a fixed depth of boundary regions. Finally, the MADI simulation results are compared with both those of the traditional ADI with uniform grids and experimental measurements. The results show the achievement of significant savings (80% - 95%) of memory requirement over uniform-grid computations with essentially no loss of precision. This result demonstrates the feasibility of using such MADI algorithms to achieve high resolution (fine grid, sub-millimeter) computation for realistic organ-size simulations.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Lamb shift in heliumlike uranium (U90

We report a value of 70.4 \ifmmode\pm\else\textpm\fi{} 8.3 eV for the one-electron Lamb shift in uranium, in agreement with the theoretical value of 75.3 \ifmmode\pm\else\textpm\fi{} 0.4 eV. We extract our Lamb shift from a beam-foil time-of-flight measurement of the (54.4 \ifmmode\pm\else\textpm\fi{} 3.4)-ps lifetime of the $1s2{p}_{\frac{1}{2}}^{3}P_{0}$ state of heliumlike uranium.
Principal ideals in the semigroup of binary relations on a finite set: What happens when one element is added to the set

The principal ideals in the semigroup of binary relations on a finite set X form a partially ordered set under inclusion. When the cardinality of the set X is increased by one, some of the covering relations present in the original set will be preserved and some will not. This article describes the difference.
A Tunable Diode Laser Absorption Diagnostic for Studying the Fire Suppression Mechanism of Aqueous High Expansion Foams

Using direct-tunable diode laser absorption spectroscopy, we obtained simultaneous oxygen, water vapor, and temperature measurements in situ during aqueous high expansion foam-suppressed fires in a foam-adapted cup burner apparatus. Foams with expansion ratios ranging from 55:1 to 129:1 were delivered at various rates; measurements were obtained 5.5 cm above and 1.5 cm outside the cup burner exit. By monitoring water vapor as foam advances through the cup burner chimney with and without the flame present, we are able to quantify evaporation due to the presence of the thermal and radiating field. We are also able to measure the impact on the oxygen concentration resulting from flame consumption of oxygen versus release of oxygen from evaporating foam bubbles. By analyzing video captured during each foam injection event, foam velocities during fire suppression and in the absence of the flame were measured.
Law, professional practice, and university preparation: Where do we go from here?

Abstract In this time of legal decisions which call much professional practice into question, it is well to ask ourselves questions as to why we are the object of court concern and how our preparation is related to our difficulties. It is suggested that current psychological practice is basically Aristotelian in nature and that our specialty suffers as a consequence. Several suggestions are presented for adjustments in university preparation. Intelligence testing and ability grouping are referred to throughout, for they have been primary targets of the courts. Examples pertaining to personality and other often measured psychological variables could have as appropriately been offered.
Detection of explosives by Terahertz synthetic aperture imaging—focusing and spectral classification

Abstract In the adaptation of Terahertz (THz) synthetic aperture imaging to stand-off screening of concealed weapons and explosives, the incoming THz wavefronts exhibit significant curvature that must be considered in the image reconstruction. Consequently, the imaging array must be focused at a specific distance to correct for the wavefront curvature. In addition to the focusing correction, detection of explosives requires spectral analysis of the reconstructed THz image. Kohonen self-organizing maps are shown to be promising tools for differentiating the spectral signature of C4 explosive from the reflection spectra of metal and semi-transparent barrier materials. To cite this article: A. Sinyukov et al., C. R. Physique 9 (2008).
Radiologic Screening for Breast Cancer: Current Controversies

Breast cancer is the most commonly occurring cancer, aside from skin cancer, among American women and the second leading cause of cancer death. Screening with mammography has been used for decades in this country, and since its introduction, there has been a reduction in breast cancer mortality. However, controversy surrounding the use of mammography to screen for breast cancer continues. In addition, the development of newer imaging techniques that can be applied to breast cancer screening has generated further debate about the value and appropriate use of radiologic imaging for breast cancer screening.
Dyskeratosis in Bowen's disease.

SUMMARY.— Dyskeratosis is a feature of certain benign and malignant epithelial disorders. In Bowen's disease, dyskeratosis is characterized by central displacement, aggregation and condensation of tonofilaments within individual cells at all levels of the epidermis. This premature keratinization is primary and is similar to the benign dyskeratosis observed in keratosis follicularis. Centrally displaced dyskeratotic material was observed intermingled with the mitotic apparatus. Giant cells apparently resulted, since nuclear but not cytoplasmic division was seen. Dyskeratosis may also be secondary, through phagocytosis by one cell of partly or completely keratinized material from other cells. This may result in formation of a second distinct type of giant cell.
A Monte Carlo Simulation of Homogeneous Crystallization in Confined Spaces: Effect of Crystallization Kinetics on the Avrami Exponent

Homogeneous nucleation in polymers and subsequent crystallization in spaces confined relative to spherulitic dimensions in one direction has been simulated for a wide range of nucleation and growth rates. An empirical Equation based on simulation results relating an Avrami exponent of crystallization to growth and nucleation rates along with the characteristic dimension of crystallizing volume has been proposed. It was found that for ideal homogeneous crystallization, the Avrami exponent can be significantly lower than the anticipated values for free unconstrained growth; therefore, all crystallization conditions and parameters must be taken into account in order to make a conclusion on the character of the observed crystallization.
The stability of water in Io

Various processes have been examined to determine their impact on water loss from Io and the formation of an anhydrous surface. Thermal escape, photolysis, and gas-phase charged particle interactions are shown to be unimportant. Recent laboratory experiments have shown that charged-particle sputtering is likely to be an effective mechanism for the removal of water ice from Io's surface. Vaporization of ice by meteoroid impacts may also be significant. The overall sputtering rate appears to be sufficiently high that the formation of a substantial regolith due to meteoroid bombardment will be prevented. However, meteoroid bombardment is probably capable of maintaining a thin (about 500 microns) overturned surface layer from which all free water has been removed by sputtering. Alternatively, a thick anhydrous surface layer may have formed on Io as the result of primordial heating. The survival of such a layer to the present implies the absence of subsequent water evolution onto the surface of the satellite.
Discussion on “Sequential Design and Estimation in Heteroscedastic Nonparametric Regression” by Sam Efromovich

Abstract Motivated from a simple change-point model, several problems are proposed for developing sequential estimation procedures for irregular regression functions.
The determinants of domestic right-wing terrorism in the USA: Economic grievance, societal change and political resentment

This study tests three categories of motivations for domestic right-wing terrorism in the USA: economic grievances, particularly those produced by economic restructuring; societal changes that chal...
The evolutionary history of two bifunctional proteins that emerged in the purple bacteria

Abstract Biochemical pathways in prokaryotes can be traced through evolution provided that a phylogenetic tree is available and that a suitable array of alternative character states are known for the pathway under study. The evolutionary histories of two bifunctional proteins that participate in aromatic amino acid biosynthesis in some Gram-negative bacteria are developed as cases in point. The P-protein of phenylalanine biosynthesis is shown to be of ancient origin within the purple bacteria, while the T-protein of tyrosine biosynthesis is of recent origin, being restricted to enteric bacteria.
Bovine Brain Diacylglycerol Lipase: Substrate Specificity and Activation by Cyclic AMP-dependent Protein Kinase

Diacylglycerol lipase (EC 3.1.1.3) was purified from bovine brain microsomes using multiple column chromatographic techniques. The purified enzyme migrates as a single band on SDS-PAGE and has an apparent molecular weight of 27 kDa. Substrate specificity experiments using mixed molecular species of 1,2-diacyl-sn-glycerols indicate that low concentrations of Ca2+ and Mg2+ have no direct effect on enzymic activity and 1,2-diacyl-sn-glycerols are the preferred substrate over 1,3-diacyl-sn-glycerols. The enzyme hydrolyzes stearate in preference to palmitate from the sn-1 position of 1,2-diacyl-sn-glycerols. 1-O-Alkyl-2-acyl-sn-glycerols are not a substrate for the purified enzyme. The native enzyme had a V max value of 616 nmol/min mg protein. Phosphorylation by cAMP-dependent protein kinase resulted in a threefold increase in catalytic throughput (V max = 1,900 nmol/min mg protein). The substrate specificity and catalytic properties of the bovine brain diacylglycerol lipase suggest that diacylglycerol lipase may regulate protein kinase C activity and 2-arachidonoyl-sn-glycerol levels by rapidly altering the intracellular concentration of diacylglycerols.
In‐flight calibration and performance of the Mars Exploration Rover Panoramic Camera (Pancam) instruments

[1] The Mars Exploration Rover Panoramic Camera (MER/Pancam) instruments have acquired more than 60,000 high-resolution, multispectral, stereoscopic images of soil, rocks, and sky at the Gusev crater and Meridiani Planum landing sites since January 2004. These images, combined with other MER data sets, have enabled new discoveries about the composition, mineralogy, and geologic/geochemical evolution of both sites. One key to the success of Pancam in contributing to the overall success of MER has been the development of a calibration pipeline that can quickly remove instrumental artifacts and generate both absolute radiance and relative reflectance images with high accuracy and precision in order to influence tactical rover driving and in situ sampling decisions. This paper describes in detail the methods, assumptions, and models/algorithms in the calibration pipeline developed for Pancam images, based on new measurements and refinements performed primarily from flight data acquired on Mars. Major calibration steps include modeling and removal of detector bias signal, active and readout region dark current, electronic “shutter smear,” and pixel-to-pixel responsivity (flatfield) variations. Pancam images are calibrated to radiance (W/m2/nm/sr) using refined preflight-derived calibration coefficients, or radiance factor (I/F) using near-in-time measurements of the Pancam calibration target and a model of aeolian dust deposition on the target as a function of time. We are able to verify that the absolute radiance calibration of most Pancam images is accurate to within about 10% or less and that the filter-to-filter and pixel-to-pixel precision of the calibrated relative reflectance data (both based on measurements of the Pancam calibration target) are typically about 3% and 1% or less, respectively. Examples are also presented of scientific applications made possible by the high fidelity of the calibrated Pancam data. These include 11-color visible to near-IR spectral analysis, calculation of “true color” and chromaticity values, and generation of “super resolution” image data products. This work represents a follow-on and enhancement to the Pancam preflight calibration process described by Bell et al. (2003).
Anomalous viscosity due to electrostatic turbulence

Abstract We calculate a general expression for anomalous viscosity due to weak, short wavelength turbulence in a plasma, and we compare it with a similar result for anomalous resistivity.
Numerical study of pressure forcing of wind on dynamically evolving water waves

We simulate the dynamic evolution of nonlinear water waves coupled with wind turbulence. We first investigate simple wave trains to obtain pressure distribution, based on which parameters for wave growth are quantified and their dependence on wave age and wave steepness is shown. We then investigate broadband waves to obtain physical insights to wind forcing for phase-resolved wavefield simulation. It is found that for long wave components, the wave growth parameter can be approximated by the value of the corresponding monochromatic waves; for short waves, stochastic modeling is suggested.
The Diurnal Variation of Hepatic HMG-CoA Reductase Activity Is Due to Changes in the Level of Immunoreactive Protein

The diurnal variation in levels of hepatic HMG-CoA reductase immunoreactive protein and enzyme activity were determined in rats. Immunoreactive protein levels changed together with enzyme activity. Thus the catalytic efficiency of HMG-CoA reductase was not significantly changed. The data suggest that the diurnal variation in hepatic HMG-CoA reductase activity is due to changes in enzyme protein levels rather than changes in phosphorylation state of the enzyme, for example, which would cause changes in catalytic efficiency.
Machining times and costs analyzed on a programmable calculator

Abstract Two sets of programs for analyzing machine shop operations have been developed for application by a programmable calculator. The first set generates time standards for a wide variety of metal cutting and grinding operations: the second per performs an analysis of the costs of labor, machinery, and tooling.Thiis latter analysis also produces the optimum machine speed to employ to minimize production time or cost, or to maximize profit.
The Mother‐Child Relationship in the HIV‐1 Positive Family

Qualitative data (N = 80) from a larger study of HIV-1 positive mothers have revealed mother-child relationships, that is, a strong attachment along with a bond of secrecy. The relationship is described as a strong attachment along with a bond of secrecy. Children are perceived by the mothers as sources of support as well as sources of stress in the relationship. We conclude that practice and policy decisions concerning HIV-1 positive mothers should include emphasis on maintaining the health of the mother-child dyad, providing respite to mothers and providing support for future planning.
Benchmarking Financial Assessment in the Strategy Course: A Qualitative and Quantitative Template

Abstract In this article, the authors present a financial assessment template for Strategic Management and Finance courses. The template is particularly useful in capstone Strategic Management courses that rely on financial analysis for strategic analysis, strategy evaluation, discussion, and debate. The template facilitates a qualitative and quantitative assessment of multiple performance criteria through a multistage benchmarking process and significantly extends the framework of an earlier benchmarking template published in the Journal of Education for Business a few years ago.
Enhancement of arsenic trioxide-mediated changes in human induced pluripotent stem cells (IPS).

Induced pluripotent stem cells (IPS) are an artificially derived type of pluripotent stem cell, showing many of the same characteristics as natural pluripotent stem cells. IPS are a hopeful therapeutic model; however there is a critical need to determine their response to environmental toxins. Effects of arsenic on cells have been studied extensively; however, its effect on IPS is yet to be elucidated. Arsenic trioxide (ATO) has been shown to inhibit cell proliferation, induce apoptosis and genotoxicity in many cells. Based on ATOs action in other cells, we hypothesize that it will induce alterations in morphology, inhibit cell viability and induce a genotoxic effect on IPS. Cells were treated for 24 hours with ATO (0–9 µg/mL). Cell morphology, viability and DNA damage were documented. Results indicated sufficient changes in morphology of cell colonies mainly in cell ability to maintain grouping and ability to remain adherent. Cell viability decreased in a dose dependent manner. There were significant increases in tail length and moment as well as destruction of intact DNA as concentration increased. Exposure to ATO resulted in a reproducible dose dependent sequence of events marked by changes in morphology, decrease of cell viability, and induction of genotoxicity in IPS.
A demographic model explains life‐history variation in Arabis fecunda

Summary 1. The distinction between semelparity and iteroparity is one of the most fundamental in life-history biology. Despite an abundance of theory proposed to explain the evolution of this dichotomy, few quantitative empirical tests exist. 2. We report here on life-history variation in the perennial herb Arabis fecunda (Brassicaceae), in which differences in the frequency of iteroparity and terminal flowering (facultative semelparity) are expressed among populations. These differences are consistent over time, and a common garden experiment suggested that they may be at least partly genetically based. 3. An analysis of demographic data over a 5-year period from three populations indicated that a simple demographic model of life-history evolution is consistent with life-history variation in this species. Individuals in populations with greater mean adult survival were more likely to express iteroparity than individuals in populations with lower adult survival.
The Biochemistry of Somatic Hypermutation

Affinity maturation of the humoral response is mediated by somatic hypermutation of the immunoglobulin (Ig) genes and selection of higher-affinity B cell clones. Activation-induced cytidine deaminase (AID) is the first of a complex series of proteins that introduce these point mutations into variable regions of the Ig genes. AID deaminates deoxycytidine residues in single-stranded DNA to deoxyuridines, which are then processed by DNA replication, base excision repair (BER), or mismatch repair (MMR). In germinal center B cells, MMR, BER, and other factors are diverted from their normal roles in preserving genomic integrity to increase diversity within the Ig locus. Both AID and these components of an emerging error-prone mutasome are regulated on many levels by complex mechanisms that are only beginning to be elucidated.
Motion-Detecting Circuits in Flies: Coming into View

Visual motion cues provide animals with critical information about their environment and guide a diverse array of behaviors. The neural circuits that carry out motion estimation provide a well-constrained model system for studying the logic of neural computation. Through a confluence of behavioral, physiological, and anatomical experiments, taking advantage of the powerful genetic tools available in the fruit fly Drosophila melanogaster, an outline of the neural pathways that compute visual motion has emerged. Here we describe these pathways, the evidence supporting them, and the challenges that remain in understanding the circuits and computations that link sensory inputs to behavior. Studies in flies and vertebrates have revealed a number of functional similarities between motion-processing pathways in different animals, despite profound differences in circuit anatomy and structure. The fact that different circuit mechanisms are used to achieve convergent computational outcomes sheds light on the evolution of the nervous system.
A practical synthesis of (11-mercaptoundecyloxy)-triethylene glycol: a valuable precursor for multicomponent self-assembled monolayers

HSC11EG3OH (1) is an important component for formation of protein-resistant self-assembled monolayers on gold. Chromatography of small molecules containing oligoethylene units, such as 1 and its synthetic intermediates, are typically complicated by smearing on TLC, making separation tedious. We have developed a convenient modification for synthesis of 1 by using a UV–visible intermediate facilitating column chromatography of the desired compound.
Liver elasticity and viscosity quantification using shearwave dispersion ultrasound vibrometry (SDUV)

Noninvasive quantification of liver elasticity is a promising alternative to liver biopsy to stage liver fibrosis, a condition afflicting hundreds of millions of patients worldwide. Quantitative measurement of elasticity (in unit of Pascal) is required in this application because liver fibrosis is a diffuse disease where abnormality is not confined to a local region and there is no normal background tissue to provide contrast. SDUV uses an ultrasound “push” beam to stimulate formation of propagating harmonic shear waves in the studied tissue. The propagation speed of induced shear waves is frequency dependent (dispersive) and relates to the tissue's mechanical properties. Shear wave speeds at multiple frequencies (typically hundreds of Hertz) are measured by a separate ultrasound “detect” beam in pulse echo mode and fit with a theoretical dispersion model to inversely solve for tissue elasticity and viscosity. A special pulse sequence has been developed to facilitate a single ultrasound array transducer for both push and detect function, which makes SDUV compatible with current ultrasound scanners. Feasibility of this pulse sequence is demonstrated by in vivo SDUV measurements in porcine liver using a dual transducer prototype.
How Complementarity and Substitution Alter the Customer Satisfaction–Repurchase Link:

Abstract Customer satisfaction is universally acknowledged as a key driver of customer repurchase behavior, but recent evidence suggests that satisfaction has no effect on repurchase under certain circumstances. In this study, the authors develop a framework for understanding the complex relationships among satisfaction, moderating variables, and repurchase. They propose that the satisfaction–repurchase link is subject to complementary and substitute effects and present satiation and inertia as key theoretical mechanisms that explain and predict those effects. In weak-satiation purchase categories, complementary effects are more likely, which suggests that managers should invest in customer satisfaction and complementary initiatives simultaneously. In strong-satiation purchase categories, substitute effects are more likely, which suggests that managers should invest in either customer satisfaction or substitute initiatives. An empirical test combining survey and longitudinal purchase data from two categor...