cssi/SciSciGPT-SciSciNet huggingface dataset:
Energy transfer and excitation migration in organic semiconductors

Energy transfer plays a key role in various applications of organic semiconductors such as electroluminescence, photovoltaics, and sensors. We have carried out a study combining transient and continuous wave (CW) optical spectroscopy with modeling. The fluorescence spectra and dynamics of a functionalized pentacene doped into a fluorescent host (Alq3) were measured and simulated by a Monte Carlo model incorporating distributed dopants and exciton migration. For nonluminescent materials, transient absorption spectroscopy provides insight into excitation migration. Singlet diffusion rates in C60 were determined by probing delayed charge transfer to ZnPc in films with a layered nanostructure.
Trends in Pediatric Appendicitis and Imaging Strategies During Covid-19 in the United States.

Rationale and Objectives To determine if, during the first wave of the COVID-19 pandemic, 1) the proportion of complicated appendicitis changed, and 2) if imaging strategies for appendicitis in children changed. Materials and Methods Retrospective cross-sectional study using administrative data from the Pediatric Health Information System, inclusive of pediatric patients diagnosed with appendicitis from March to May in 2017, 2018, 2019 and 2020. We compared trends during COVID-19 pandemic (March–May 2020) with corresponding pre-COVID-19 periods in 2017–201.9 Study outcomes were the proportion of complicated appendicitis and trends in imaging for appendicitis explained by patient-level variables. Results The proportion of complicated appendicitis cases increased by 4.4 percentage points, from 46.5% pre-COVID-19 (2017–2019) to 50.9% during COVID-19 (2020), p Conclusion During the first wave of the COVID-19 pandemic, the proportion of complicated appendicitis cases increased without an absolute increase in the number of complicated appendicitis cases, but instead a decrease in the number of uncomplicated acute appendicitis diagnoses.
Airplane Longitudinal Stability - A Resume

j \ / T O R E than twenty-five years ago, a rational 1 T A method of calculating the stability of airplanes was developed by Bryan and published in his Stability in Aviation. He laid the ground so well that in the main, no fundamental change in the method has appeared since. However, aerodynamic phenomena, wellunderstood at present, were not amenable to close evaluation at the time the method was first presented. It was, therefore, exceedingly difficult to predict the behavior of airplanes, when the calculation of the quantities to be substituted in the stability equations was, at best, uncertain. In the intervening time, research workers have, along with the general progress of aerodynamic science, developed improved methods of evaluating the so-called stability derivatives, on which the calculations rest. This has resulted in placing stability calculation, for the region below the stall at least, on a practical basis. Although the theory is based on the assumption of infinitesimally small disturbances, experience has demonstrated that stability may be predicted relative to disturbances normally experienced by an airplane in steady flight with sufficient precision for all practical purposes. The application of stability theory to the design of airplanes was pioneered in this country by Hunsaker whose work ' pointed out the desirability and practicability of such computation as early as 1915. Since that time the method has languished and the airplane designer has made little use of the only existent means of stability analysis which bears any relation to reality. Indeed, he is usually only vaguely aware of "dynamic" stability as "something you don't have to worry about." However, in justice to the designer, it must be said that should he attempt to undertake such an analysis, it would be necessary for him., in order to obtain the required data, to search through a great many technical books and reports, only some of which are useful, and all couched in unfamiliar language. Further than this, such data are usually presented in a form not immediately applicable to the airplane designer's needs. The designer is usually content to insure that the airplane has a degree of "static" stability, determined by the
Shape Optimization: Creating a Useful Design Tool

Several new areas of research are presented which seek to eliminate some of the barriers to achieving a useful design optimization tool. These areas include consideration of geometrical and topological optimization as well as crossectional optimization, design for latitude uncertainty in loading conditions and problem formulation, member insertion and deletion, new elements for optimization and fundamental new approaches to combine analysis and optimization. The role new computing hardware will play in the implementation of the next generation design tool is investigated. Work in several of these areas will be described. Results for shape optimization using the boundary integral method with substructuring, zero-one integer programming for decision support and a means of performing the analysis within the shape optimization formulation are presented.
The effect of valproic acid on notch signaling in Danio rerio intestinal cell differentiation

Inflammatory bowel disease (IBD) is a classification of chronic remittent immune disorders affecting approximately 1.4 million people in the United States between the ages of 15 and 40. It is thoug...
Gas sensing fiber network with simultaneous multi-node detection using range-resolved chirped laser dispersion spectroscopy

We present a laser-spectroscopic method for continuous and simultaneous interrogation of multiple passive gas sensor nodes in a fiber based sensor network. Enabled by chirped laser dispersion spectroscopy, methane leak detection is demonstrated as an example application.
Genital herpesvirus (type II) strain differences.

Abstract Herpesvirus Type II was isolated from genital lesions of 18 patients. Two distinct strain differences were noted within these Type II isolates. The cytopathic effects produced by one patient's virus strain in WI-38 and HeLa cell cultures were distinctly different from all other isolates. No clinical significance can be attributed to this biologic difference at this time.
Lateral Stability of Wood Beam-and-Deck Systems

Modern timber structures frequently employ large wood beams bridged by 2 in. wood decking. Economy of material dictates the use of deep narrow beams whose design is limited by considerations of lateral instability. Such constructions must rely upon the in-plane shear rigidity of the attached deck to prevent collapse, yet when decks of low rigidity such as 2 in. decks are employed, the stability of the resulting structure is seriously in question. This report quantitatively answers the question of how much shear rigidity a deck must possess in order to provide adequate lateral support when attached to the top of a set of deep beams. A variational method of derivation is employed, and buckling curves are presented for five cases of load and support. The use of these results by structural engineers will facilitate the safe design of lightweight economical wood structures.
Using Message-Oriented Middleware for Reliable Web Services Messaging

Web Services hold the promise of a standards-based platform for automating the integration of applications over diverse networks, operating systems and programming languages. Reliable messaging is critical in this context; many enterprise systems require a messaging infrastructure that guarantees message delivery even in the presence of software and network failures. Using existing message-oriented middleware (MOM) for reliable Web services messaging seems natural. However, a variety of implementation challenges, including the support for specific reliable Web services messaging protocols, must be addressed. In this paper, we discuss the options for and implications of employing MOM to implement reliable messaging for Web services. In doing so, we contribute to the understanding of reliability for Web services in general.
Determinants of egg load in the soybean aphid parasitoid Binodoxys communis

We used a series of laboratory studies to investigate factors contributing to variability in egg load of the parasitoid Binodoxys communis (Gahan) (Hymenoptera: Braconidae), a biological control agent of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae). The change in egg load in newly emerged females over time was determined in response to three treatments: post-eclosion temperature, sugar meals, and host density. Binodoxys communis females emerge with an average egg load of approximately 40 mature eggs that increases to approximately 200 eggs within 24 h of emergence. The egg maturation rate over this time period is higher when females are held at 26 °C than at 18 °C. And although the egg load of sugar-fed females was slightly higher than that of starved females, this difference was not statistically significant. Binodoxys communis females that were held with 150 hosts for 8 h laid more eggs than those that were held with 30 hosts, and they also matured more eggs over the subsequent 16 h than those held with 30 hosts or no hosts at all. However, we detected no difference in the egg maturation pattern between B. communis females held with the low host density and that of control females held with no hosts at all. Thus, we conclude that enhanced egg maturation in the higher host-density treatment is more likely explained by a rapid replenishing of partially depleted ovaries than a host-induced stimulus of egg maturation per se. Taken together, these results suggest a strategy of maintaining a high egg load and thus avoiding or mitigating the negative effects of egg limitation.
Calculation of infrared limb emission by ozone in the terrestrial middle atmosphere. I - Source functions. II - Emission calculations

The departure from LTE in the vibration-rotation bands of ozone in the middle atmosphere is analyzed using two statistical equilibrium models: the energy gap model and the simplified single model. The diurnal variations in the fundamental band source functions nu(1) and nu(3) is determined by the diurnal change in the rate of ozone photolysis by the solar radiation. Source functions are presented for the vibration-rotation bands of ozone that emit in the 9-11-micron spectral interval, over an altitude range of 1-110 km. Results are also reported of the evaluation of the radiative transfer equation incorporating these source functions and energy level populations. Using the results of the two statistical equilibrium models, calculations are carried out of the spectrally integrated limb radiance for the limb viewing geometry for daytime conditions. Results indicate that the interpretation of the measurements of spectrally integrated limb radiance from ozone will be greatly complicated by the breakdown of LTE in the vibration-rotational bands of ozone.
Defects in fruiting body development caused by Tn5 lac insertions in Myxococcus xanthus.

Mutations caused by insertions of Tn5 lac that block development are rare. At least six of the eight mutations examined appeared to be regulatory. Three of these were found to disrupt social motility, suggesting a particular importance for this function. One other occurred in a known cell-cell interaction gene, bsgA, and the remaining two were located in genes operative early in the developmental program. Images
Cholesterol metabolism in rhesus monkey, squirrel monkey, and baboon.

The metabolism of cholesterol was studied in ba- boons, rhesus monkeys, and squirrel monkeys while they were being fed either a low fat, low cholesterol (basal) diet or the basal diet supplemented with saturated fat and cholesterol (ath- erogenic diet). When the diet was changed from basal to athero- genic, the mean total serum cholesterol concentration increased from 70 to 180 mg/dl in the baboon, from 168 to 283 mg/dl in the squirrel monkey, and from 144 to 608 mg/dl in the rhesus monkey. In animals fed the atherogenic diet, the percentage of dietary cholesterol absorbed was greatest in the rhesus monkey and least in the baboon. The fraction of the total body pool of cholesterol that was derived from the diet was greatest in the squirrel monkey and least in the baboon. The turnover of the body pool of cholesterol was several times faster in the squirrel monkey than in the baboon or the rhesus monkey when either dict was fed. The mean total fecal excretion of endogenous cho- lesterol and bile acid increased in all species on transition to the atherogenic diet; however, the relative contributions of the neu- tral and acidic fractions to the increase in total excretion differed among species. The difference in percentage of dietary cholester- ol absorbed may, in part, account for the large differences in serum cholesterol during the atherogenic diet period. Compari- son with other published results indicates that of these species cholesterol metabolism in the baboon is most like that in the human.
Reply: Repeatability of Tumor SUV Quantification: The Role of Variable Blood SUV

REPLY: My coauthors and I thank Drs. van den Hoff and Hofheinz for their comment. Our paper ([1][1]) focused on commonly used parameters for quantifying tumor 18F-FDG uptake (SUVpeak and SUVmax). However, we fully agree that there are several other potential ways to normalize tumor 18F-FDG uptake.
Property Rights Theory and the Formulation of Financial Statements

This article explains and demonstrates, by way of proposed financial statements, a practical application of a theory (property rights) that has important implications for financial reporting and for the FASB's conceptual framework project.
A new explicit and unconditionally stable FDTD method for analyzing general lossy problems

In this paper, a new explicit and unconditionally stable finite-difference time-domain (FDTD) method is developed for analyzing general lossy problems. Both conductor loss and dielectric loss in inhomogeneous materials are considered. The root cause of instability is directly eradicated from the FDTD numerical system before performing explicit time marching. Numerical simulations have demonstrated the accuracy, efficiency, and unconditional stability of the new method.
A Chromogenic Bioluminescent Bacterium Associated with the Entomophilic Nematode Chromonema heliothidis1

A bacterium, designated as strain NC-19, was found to be associated intimately with the entomophilic nematode Chromonema heliothidis. The bacterium is a conspicuously large asporogenous rod, which is Gram-negative, motile with peritrichous flagella, aerobic to facultatively anaerobic, bioluminescent, and chemoorganotrophic, and which grows well on nutrient agar, forming cream-colored colonies that turn pink-red with age. The deoxyribonucleic acid base composition is 45.6 mol% guanine plus cytosine. Bacterium NC-19 shares a number of morphological, biochemical, physiological, and ecological characteristics in common with Achromobacter nematophilus. It is differentiated by its chromogenic slimy viscid colonies on nutrient agar and by its high lipolytic and bioluminescent properties. A culture of the bacterium has been deposited with the American Type Culture Collection as an unidentified bacterium with accession No. 29304.
Turning p53 on or off: either way may treat cancer.

Abstract The p53 tumor suppressor gene is likely the most commonly mutated tumor suppressor gene in human cancer. Its functions include modulation of both cell cycle arrest and apoptosis. Animal models and human clinical data suggest that in some settings, p53 may be prognostically significant, reflecting its role as a key regulator of cell death during cancer therapy. Two recent strategies have been proposed to exploit p53’s unique death-regulating activity in opposite directions and improve cancer treatment. One approach seeks to inhibit p53 in normal cells thereby diminishing therapy-related, p53-dependent toxicity. The other utilizes a peptide derived from the C-terminus of p53 to activate wild-type or mutant p53 proteins, triggering apoptosis with selectivity for transformed cells. These novel approaches hold promise for targeting p53 in cancer therapy and may shed light on mechanisms underlying the role of p53 in cancer cell survival.
Deltaherpeton hiemstrae, a New Colosteid Tetrapod from the Mississippian of Iowa

A new colosteid, Deltaherpeton hiemstrae gen. et sp. nov., is described from the Mississippian Upper Visean site at Delta, Iowa. Deltaherpeton is represented by a skull roof and both jaws. The new taxon is unique among colosteids in having an internasal and single midline postparietal. An additional midline pair of cf. ‘interfrontonasals’ may be present. Characters previously used to define the colosteids are reviewed and a refined diagnosis for the family Colosteidae is presented. Synapomorphies which unite Deltaherpeton, Colosteus, Greererpeton, and Pholidogaster as Colosteidae are: premaxilla with fang pair; dentary with notch for receipt of premaxillary fang; mandible with single elongate exomeckelian fenestra; pre-narial infraorbital lateral line terminating at ventral margin of premaxilla just anterior to external naris; and post-narial infraorbital lateral line terminating at the ventral margin of the maxilla just posterior to the external naris. Our review of dermal bones in the colosteid snout concludes that no specimen is sufficiently free of distortions or breakage to indicate clearly whether or not the prefrontal borders the external naris, or that an anterior tectal is present. The morphology of Deltaherpeton and the revised data presented for colosteids do not clarify the relationship of colosteids to other early tetrapods.
Effect of Inoculum Rate of Biological Control Agents on Preharvest Aflatoxin Contamination of Peanuts

Studies were conducted during 1994 and 1995 in the environmental control plot facility at the National Peanut Research Laboratory to determine the effect of different inoculum rates of biological control agents on preharvest aflatoxin contamination of Florunner peanuts. Biocontrol agents were nontoxigenic color mutants ofAspergillus flavusandAspergillus parasiticusthat were grown on rice for use as soil inoculum. Three replicate plots (4.0 × 5.5 m) were treated with 0, 2, 10, and 50 g/m of row (0, 20, 100, and 500 lb/acre, respectively) of an equal mixture of the color mutant-infested rice in 1994, and the same plots were retreated in 1995. Aflatoxin concentrations were determined by high performance liquid chromatographic analysis of all peanuts. Treatment means for total kernels in 1994 were 337.6, 73.7, 34.8, and 33.3 ppb for the 0, 2, 10, and 50 g/m treatments, respectively. Regression analysis indicated a trend toward lower aflatoxin concentrations with increasing rates of inoculum (R2= 0.40;P< 0.05). For the same repeated treatments in 1995 aflatoxin concentrations in total kernels averaged 718.3, 184.4, 35.9, and 0.4 ppb. Regression analysis revealed a stronger relationship between inoculum rate and aflatoxin concentrations (R2= 0.66;P< 0.05) in the second year of treatment. Compared with untreated controls, the 2, 10, and 50 g/m treatments produced respective reductions in aflatoxin of 74.3, 95.0, and 99.9% in the second year. The data indicated not only a treatment-related effect, but also that a higher degree of control might be achieved when plots or fields are retreated with biocontrol agents in subsequent years.
Feeling green: mechanosensing in plants

Owing to the sessile nature of their lifestyle, plants have to respond to a wide range of signals, such as the force of the wind or the impedance of the soil, to entrain their development to prevailing environmental conditions. Indeed, mechanically responsive growth has been documented in plants for many years but new work on lateral root formation strongly supports the idea that biophysical forces can elicit complete de novo developmental programs. In addition, only recently have molecular candidates for plant mechanosensors emerged. Such advances in understanding plant mechanoresponsive development have relied heavily on comparison with mechanosensors characterized in organisms such as Saccharomyces cerevisiae and Escherichia coli, but key questions remain about the cellular basis of the plant mechanosensory system.
Recreational and community activities of dentists

Abstract Few studies have adequately examined the leisure time activities and community participation among dentists. The present report examines the recreational and community activities of 413 practicing dentists in the United States. The findings demonstrated that dentists in the present sample were more recreationally oriented than community oriented. Recreation was most often interpreted as meaning sports activities. Dentists were noticeably different in sports participation from the general male population in that dentists tend to prefer individual or partner sports over team sports. Participation in community activities was analyzed by age and income. Age and participation in community activities demonstrated a positive moderate correlation and participation does not decrease with the age of the dentists.
Episodic Volcanism in the Central Oregon Cascade Range

Radiometric dating of late Cenozoic igneous rocks of the central Oregon Cascade Range has shown that volcanic activity has been strongly episodic, with most lavas erupting during short intervals of 1 or 2 m.y. The strongest activity occurred during middle Miocene time concurrently with eruption of the Columbia River Basalt. Subsequent episodes followed at about 5-m.y. intervals. Preliminary data from other parts of the circum-Pacific area suggest that these same episodes occurred in unison over a large part of the Earth.
The Astronomers' Game: Astrology and University Culture in the Fifteenth and Sixteenth Centuries

The formal study of both astronomy and astrology in later medieval Europe was firmly based in the universities. Instruction in astrology is attested by the presence of an educational board game, known as the ludus astronomorum, in several university-related miscellanies of fifteenth-century English provenance. William Fulke also published an edition of the game a century later (Ouranomachia, London, 1571), which is attested in a number of Elizabethan libraries. The game serves to rehearse for its players the celestial motions and astrological principles described by Ptolemy. It also employs principles of stellar rays described by al-Kindi in his De radiis stellarum.
Taking the Fear Out of Research: A Gentle Approach to Teaching an Appreciation for Research

This article presents a method of introducing students to research slowly and carefully. A process of integrating research into the curriculum at all levels of higher education is stressed; this approach decreases fear and avoidance. Enthusiasm and enjoyment are facilitated through close collaboration of students and faculty in the research process.
Periodic trends in transition metal-hydrogen, metal-carbon, and metal-oxygen bond dissociation energies. Correlation with reactivity and electronic structure

The strengths of bonds formed between transition metals and various substituent groups are of fundamental importance in the areas of surface chemistry, organometallic chemistry, and catalysis. The scarcity of such thermodynamic information has led us to develop new experimental methods for the determination of the thermochemical properties of organometallic species. Most important are ion beam experiments in which an examination of the translational energy dependence of endothermic reactions yields bond energies of product species.
Effects of knee flexion angles for graft fixation on force distribution in double-bundle anterior cruciate ligament grafts.

BackgroundIn double-bundle anterior cruciate ligament reconstruction, overloading either 1 of the 2 grafts should be avoided to decrease the risk of graft failure.HypothesisOverloading of the posterolateral graft may occur when it is fixed at 30 ° of knee flexion because the posterolateral bundle is elongated as the knee approaches extension.Study DesignControlled laboratory study.MethodsTen human cadaveric knees were tested at (1) intact, (2) anterior cruciate ligament–deficient, (3) double-bundle anterior cruciate ligament reconstruction with the anteromedial and posterolateral grafts fixed at 60 ° of flexion and full extension, respectively (fixation 60/FE), and (4) double-bundle anterior cruciate ligament reconstruction with both grafts fixed at 30 ° of flexion simultaneously (fixation 30/30). Two external loading conditions simulating clinical examinations were used: (1) 134-N anterior tibial load and (2) combined rotatory loads of 10 N·m valgus and 5 N·m internal tibial torques. Data on knee kinemat...
Correlation of estrogen β-receptor messenger RNA with endogenous levels of plasma estradiol and progesterone in the female rat hypothalamus, the bed nucleus of stria terminalis and the medial amygdala

Abstract Estrogen receptor β (ERβ) has been previously mapped in the rat central nervous system. This study aims to explore the regulation of ERβ mRNA as it is expressed in the intact and cycling female rat brain. Young adult female rats (90+ day, N=20) were screened for estrous phases via vaginal cytology and sacrificed. Brains and blood were collected and processed for in situ hybridization and estradiol (E2) and progesterone (P4) hormone assays, respectively. ERβ mRNA levels exhibited significant correlations with ovarian steroid ratios (E2/P4) in various brain regions, including the bed nucleus of stria terminalis, the medial nucleus of amygdala, and the anteroventral periventricular nuclei but not the paraventricular and the supraoptic nuclei or the preoptic area of the hypothalamus. No regulatory changes were detected in the cortex. Specifically, in the affected regions, higher P4 levels were significantly correlated with higher ERβ mRNA expression. In contrast, there was a tendency for higher E2 levels to be correlated with lower ERβ mRNA expression, but this tendency reached significance only in the bed nucleus of stria terminalis. These results suggest that ERβ mRNA is regulated in the intact and cycling female rat hypothalamic as well as extrahypothalamic brain regions, and the circulating ovarian hormones play a critical role.
Elderly women's clothing: acquisition, fit and alterations of ready‐to‐wear garments

The major objective of this research was to determine the clothing needs of elderly women. An interview schedule was developed to elicit information about specific clothing needs, including acquisition, fitting problems and garment alterations. Data were obtained from 150 women residing in northern Colorado. The subjects were grouped into three age categories: 30–64, 65–74, and 75 and over. Findings indicated that most women purchased ready-to-wear garments which sometimes required alterations. The most frequent alteration needed was shortening the skirt length. It was noted that with increasing age, women became less aware of needed alterations for proper fit. Elderly women did not perceive a need for garment alterations if they thought the garment was attractive and felt comfortable.
Bridging the gap between preparation and practice: A teacher educator interviews a reading supervisor

Abstract This article reports an interview between the instructor in a university undergraduate reading methods course and the reading supervisor for the local public school. The interview was conducted for the benefit of students taking the course who would subsequently student teach in those same schools. After students listened to tapes of the interview, the supervisor visited the class and answered their questions. Her suggestions about the knowledge and skills a teacher needs, and about the problems and potential of classroom reading programs served to reinforce the content of the university class. The author suggests that collaboration between reading faculty in colleges of education and public school reading personnel can strengthen preservice teacher education by helping students bridge the gap between preparation and practice.
Expository Text Comprehension in the Primary Grade Classroom.

This study investigates the effectiveness of an instructional program designed to teach 2nd graders how to comprehend compare-contrast expository text. Along with introducing new content (animal classification), the program emphasizes text structure via clue words, a sequence of questions, and a graphic organizer, and via the close analysis of specially constructed exemplar paragraphs. The authors compared the program with (a) more traditional instruction that focused only on the new content and (b) a no instruction control; 128 7- and 8-year-olds participated. Classroom teachers provided the instruction. The program improved students' ability to comprehend compare-contrast texts. Students were able to demonstrate transfer to uninstructed compare-contrast texts though not to text structures other than compare-contrast. Moreover, the text structure instruction did not detract from their ability to learn new content. The results provide evidence, heretofore lacking, that explicit instruction in comprehension is feasible and effective as early as the 2nd grade.
TREATMENT OF REFRACTORY VENTRICULAR FIBRILLATION BY COMBINED INTERNAL (EPICARDIAL) AND EXTERNAL (TRANSTHORACIC) DEFIBRILLATION

This report describes a modified defibrillation technique used successfully in a patient with an implanted epicardial cardioverter defibrillator who developed refractory ventricular fibrillation. During operative testing at the time of generator replacement, two episodes of intractable ventricular fibrillation were terminated by using a combined internal (epicardial)-external (transthoracic) defibrillation system that delivered a 360-J shock between the anterior epicardial patch and a large posterior skin electrode.
Expansion of Paneth Cell Population in Response to Enteric Salmonella enterica Serovar Typhimurium Infection

Paneth cells residing at the base of the small intestinal crypts contribute to the mucosal intestinal first line defense by secreting granules filled with antimicrobial polypeptides including lysozyme. These cells derive from the columnar intestinal stem cell located at position 0 and the transit amplifying cell located at position +4 in the crypts. We have previously shown that Salmonella enterica serovar Typhimurium (ST), a leading cause of gastrointestinal infections in humans, effects an overall reduction of lysozyme in the small intestine. To extend this work, we examined small-intestinal tissue sections at various time points after ST infection to quantify and localize expression of lysozyme and assess Paneth cell abundance, apoptosis, and the expression of Paneth cell differentiation markers. In response to infection with ST, the intestinal Paneth cell-specific lysozyme content, the number of lysozyme-positive Paneth cells, and the number of granules per Paneth cell decreased. However, this was accompanied by increases in the total number of Paneth cells and the frequency of mitotic events in crypts, by increased staining for the proliferation marker PCNA, primarily at the crypt side walls where the transit amplifying cell resides and not at the crypt base, and by apoptotic events in villi. Furthermore, we found a time-dependent upregulation of first β-catenin, followed by EphB3, and lastly Sox9 in response to ST, which was not observed after infection with a Salmonella pathogenicity island 1 mutant deficient in type III secretion. Our data strongly suggest that, in response to ST infection, a Paneth cell differentiation program is initiated that leads to an expansion of the Paneth cell population and that the transit amplifying cell is likely the main progenitor responder. Infection-induced expansion of the Paneth cell population may represent an acute intestinal inflammatory response similar to neutrophilia in systemic infection.
New research site to launch in June

Thirteen science and technology societies will launch a new Web site (http://www.scitopia. org) in June that will enable users to search more than three million journal articles, conference proceedings, and patents at once. “Scitopia.org's aim is to provide powerful, focused aggregation and an additional access point to the highest quality scientific research available on the Web today... [The site] will offer the most direct route to the very latest research, within hours of it appearing on the Web,” said Terry Hulbert, head of Electronic Development and Strategy at the Institute of Physics Publishing (IOP), one of the participating organizations.
Characteristic parameters of a granular superconductor

Starting from a simple microscopic model of a granular superconductor (cubic grains of superconductor weakly coupled by Josephson junctions separating adjacent cubes), a calculation is made of the characteristic parameters $\mathfrak{J}$ and $C$ of the continuum model of a granular superconductor, $\mathfrak{J}$ being the proportionality constant of the tunneling energy, and $C$ the proportionality constant of the electrostatic energy density. From these are calculated the characteristic frequency $\ensuremath{\omega}$ for the onset of electromagnetic oscillations, the characteristic length $\ensuremath{\xi}$, the Ginzburg-Landau coherence distance ${\ensuremath{\xi}}_{\mathrm{GL}}$, and the magnetic penetration depth $\ensuremath{\lambda}$. The last two are identical with the corresponding quantities for a dirty superconductor in the vicinity of the superconducting transition temperature. In the limit of weak magnetic fields, the identity of $\ensuremath{\lambda}$ holds for all temperatures.
Micro-Mechanical Model of a Composite Containing a Conservative Nonlinear Electro-Magneto-Thermo-Mechanical Material:

In this paper, we present an elasticity formulation using a concentric cylinders assemblage to investigate the response of a composite system containing a conservative nonlinear electro-magneto-thermo-mechanical (EMTM) material. The nonlinearity in the EMTM material is mathematically represented in the constitutive relations with terms coupling strain, electric/magnetic fields, temperature, and stress. These relations are representative of piezoelectric, electrostrictive, and magnetostrictive materials. The electric-magnetic-thermal field inside the composite material is assumed to be invariant with respect to position; this permits a closed form solution to be presented. The analytical model provides point wise stresses and strains in each constituent and is useful for evaluating possible locations for damage initiation and effective properties for the coupled material system. Parametric studies are presented to investigate the influence of constituents and actuator geometry on the material system's effe...
Flight of the Blackbird: Red Tails and Fighting for American Legitimacy

Red Tails, a recent movie about the Tuskegee Airmen in battle, is the latest in a line of movies that seem to petition for admission to the fellowship of the mainstream American society by showing stories of groups overcoming discrimination and proving their strength and their patriotism. As the most excluded and longest-lasting pariah group, African Americans have enacted this scenario in real life and in the popular culture many times. Movies about war and the military are a powerful means of showing minority group worthiness. Those who will risk their lives in battle on behalf of the homeland and will fight with extraordinary skill should be worthy applicants for inclusion.
Variational theory of flux line liquids

We formulate a variational (Hartree like) description of flux line liquids which improves on the theory developed in an earlier paper [A.M. Ettouhami, Phys. Rev. B 65, 134504 (2002)]. We show, in particular, that the massive term confining the fluctuations of flux lines is strongly reduced by thermal fluctuations. This results in an anomalous temperature dependence of the mean square projected area of a single flux line $〈{u}^{2}〉\ensuremath{\sim}{T}^{3/2}$ which is a signature of the weakly entangled state introduced previously, and which should be measurable in numerical simulations.
Double Sloped Decay: Subjective Listening Test to Determine Perceptibility and Preference:

Can music listeners, both experienced and inexperienced, distinguish a double-sloped decay from a Sabine decay? Do they prefer the double slope? A simulated space, based on an actual built coupled-volume hall, was conceived in room acoustics software to create double sloped and classic Sabine auralizations. The simulated decays were compared with in situ measurements taken in a built coupled volume concert hall for validation. The impulse responses generated were convolved with an anechoic musical recording, grouped in pairs, and played for subjects. Participants listened to the recorded pairs over headphones and were asked to determine (1) if the two recordings sounded different, (2) which recording was more likely to have a double slope or had a more dramatic double slope, and (3) which of the two recordings they prefer. The more a recording diverged from a standard Sabine decay, the more likely the respondents were to identify that recording as having a double slope. When asked to identify a preference...
Rhythm Analysis of Arterial Blood Pressure

Rhythms identified in the power spectra of blood pressure and ECG recordings were used as probes of the intact cardiovascular control systems. A prominent vasomotor rhythm was detected in human subjects and experimental dogs, with a period ranging between 15 and 30 s. This rhythm did not depend on specific rhythms of heart rate but was dependent on the sympathetic nervous system, and was identified as a third-order rhythm of blood pressure. The parasympathetic nervous system appears to mediate a separate rhythm having a slightly shorter period. Another rhythm studied was a subharmonic of heart rate that appeared during episodes of tachycardia. Electrophysiological mapping of the ventricular surface in dogs revealed that tachycardia induced an alternating pattern of electrical conduction in ischemic areas of the ventricle, coincident with the appearance of subharmonics in pressure and ECG. Our results illustrate the potential utility of spectral analysis of cardiovascular signals in assessing cardiovascular regulation.
Flavin redox switching of protein functions.

Flavin cofactors impart remarkable catalytic diversity to enzymes, enabling them to participate in a broad array of biological processes. The properties of flavins also provide proteins with a versatile redox sensor that can be utilized for converting physiological signals such as cellular metabolism, light, and redox status into a unique functional output. The control of protein functions by the flavin redox state is important for transcriptional regulation, cell signaling pathways, and environmental adaptation. A significant number of proteins that have flavin redox switches are found in the Per-Arnt-Sim (PAS) domain family and include flavoproteins that act as photosensors and respond to changes in cellular redox conditions. Biochemical and structural studies of PAS domain flavoproteins have revealed key insights into how flavin redox changes are propagated to the surface of the protein and translated into a new functional output such as the binding of a target protein in a signaling pathway. Mechanistic details of proteins unrelated to the PAS domain are also emerging and provide novel examples of how the flavin redox state governs protein–membrane interactions in response to appropriate stimuli. Analysis of different flavin switch proteins reveals shared mechanistic themes for the regulation of protein structure and function by flavins. Antioxid. Redox Signal. 14, 1079–1091.
DNA synthesis in the oocyte of the mature mouse: a radioautographic study.

Mice were injected three times over an 8-hour period with a total of 48 mci 3H-T/gm of body weight and were sacrificed 1, 3, 5, 9 and 17 days afterwards. Radioautographs of the ovaries showed significantly higher grain counts in oocytes of follicles that are in the antrum formation stage. The radioautographic visualization of DNase digestible 3H-thymidine incorporation into the juxtanucleolar region in oocytes of mature mice occurs in association with oocyte growth in follicles that are in the antrum formation stage. The scheduled disappearance of this juxtanucleolar oocyte DNA and its label during later oocyte growth suggests a degradation or dispersion of this labeled DNA prior to ovulation.
Power series solutions to the time-varying dynamic programming equations

In this paper we construct high-order approximate solutions to the value function and optimal control for a finite-horizon optimal control problem for time-varying discrete-time nonlinear systems. The method consists in expanding the dynamic programming equations (DPE) in a power series, collecting homogeneous polynomial terms and solving for the unknown coefficients from the known and previously computed data. The resulting high-order equations are linear difference equations for the unknown homogeneous terms and are solved backwards in time. The method is applied to construct high-order perturbation controllers around a nominal optimal trajectory.
Spatial light interference microscopy (SLIM)

Spatial light interference microscopy (SLIM) is a new optical microscopy technique, capable of measuring nanoscale structures and dynamics in live cells via interferometry. SLIM combines two classic ideas in light imaging: Zernike's phase contrast microscopy, which renders high contrast intensity images of transparent specimens, and Gabor's holography, where the phase information from the object is recorded. Thus, SLIM reveals the intrinsic contrast of cell structures and, in addition, renders quantitative optical path-length maps across the sample. The resulting topographic accuracy is comparable to that of atomic force microscopy, while the acquisition speed is 1,000 times higher. We illustrate the novel insight into cell dynamics via SLIM by experiments on primary cell cultures from the rat brain. SLIM is implemented as an add-on module to an existing phase contrast microscope, which may prove instrumental in impacting the light microscopy field at a large scale.
Changes of mean magnitude of Parkfield seismicity: A part of the precursory process?

The average magnitude of earthquakes produced along the Parkfield segment of the San Andreas fault was decreased significantly between late 1986 and late 1988 along with the seismic quiescence [Wyss et al., 1990a]. The change corresponds to an increase of the b-value from 1.1 to 1.4. During the last year (1989) however, the average magnitude produced was approximately normal again. This same phenomenon had been identified before several other mainshocks. Therefore it may be interpreted as a precursor to the predicted Parkfield mainshock.
Acquired Traits Revisited

Most biology texts villify Lamarck's concept of “inheritance of acquired characters” and leave the impression that all acquired characters are never transmitted to offspring. However, recent research indicates that this is not true! Some “acquired” traits are inherited. I profile some of these striking cases and their importance for evolution and for understanding a broader epigenetic context for heredity and ontogeny (the emerging field of “evo-devo”). Further, I discuss how such cases, even considered as exceptions, contribute to understanding the nature of science, both the role of general rules in biology and the occurrence of conceptual change, or paradigm shifts.
Three Paragraphs on Avoidance Extinction

Perhaps psycholog~cts occasionally forget, as the data continue to accumulate, how simply an expectancy theory can approach a problem that may be very resistant to a reinforcement viewpoint (Ritchie, 1951; Solomon & Wynne, 1954). The following thumbnail sketch might serve as a useful reminder. In reward training and its extinction, S commonly experiences a sequence of stimulus changes terminated by an appropriate incentive; he then experiences that same sequence of events now terminated by the absence of that incentive. But such rarely occurs during extinction following avoidance training: S commonly avoids belore the complete sequence of events leading to the now-absent aversive stimulus can elapse. Thus the extinction procednre, as exemplified by extinction following reward training, may not even occur. This suggests that rhe greater persistence of the response frequently observed following avoidance training is not necessarily a reflection of the uniqueness of avoidance training but may merely indicate the absence of interference. The present interpretation is clearly an expectancy-interference one, with the expectancy permanent and the resulting behavior modifiable only by means of new and conrradictory expecrancies. No unique concepts are needed here; to the degree that the initial expectancy encounters no opposing acquisitional process, to rhat degree the behavior will not be altered. To obtain true extinction then, S must experience the same or a very similar srimulus sequence rhar he did during training but now discover the absence of the outcome of that sequence. S has every reason to "cooperate" with E during extinction following reward training to satisfy this requirement, and so he extinguishes rapidly, but little reason to do so following avoidance training, and hence the relatively greater resistance to extinction. E may, of course, attempt to accelerate avoidance extinction by physically forcing S to submit to the extinction procedure or by piwishing S for not doing so (Solomon, Kamin, & Wynne, 1953). But forcing can easily introduce distinctive changes inro the sequence oE events and thus lead to discrimination learning on the part of S rather than true exrincrion: when that force and its attendant cues are removed, the avoidance response may again reveal itself. Nor can punishment for avoiding interfere in any direct way with S's expectancy of punishment for not avoiding. And, in terms of delay, the immediate expectancy for not avoiding may well be more decisive than the eventual outcome for avoiding. REFERENCES RITCHIE, B. F. Can reinforcement theory account for avoidance? Psychol. Rev., 1951, 58, 382-386. SOLOMON, R. L., KAMIN, L. J., & WYNNE, L. C. Traumatic avoidance learning: the outcomes of several excinccion procedures with dogs. I. abnorm. soc. Psychol., 1953, 48, 291-302. SOLOMON, R. L., & WYNNE, L. C. Traumatic avoidance learning: the principles of anxiety conservation and partial irreversibility. Psychol. Rev., 1954, 61, 353-385.
A note on pretense and co-reference

Anna Pautz has recently argued that the pretense theory of thought about fiction cannot explain how two people can count as thinking about the same fictional character. This is based on conflating pretending and the serious thought that can be based on pretend. With this distinction in place, her objections are groundless.