cssi/SciSciGPT-SciSciNet huggingface dataset:
Genetic Control of Cuticle Formation During Embryonic Development of Drosophila melanogaster

The embryonic cuticle of Drosophila melanogaster is deposited by the epidermal epithelium during stage 16 of development. This tough, waterproof layer is essential for maintaining the structural integrity of the larval body. We have characterized mutations in a set of genes required for proper deposition and/or morphogenesis of the cuticle. Zygotic disruption of any one of these genes results in embryonic lethality. Mutant embryos are hyperactive within the eggshell, resulting in a high proportion reversed within the eggshell (the "retroactive" phenotype), and all show poor cuticle integrity when embryos are mechanically devitellinized. This last property results in embryonic cuticle preparations that appear grossly inflated compared to wild-type cuticles (the "blimp" phenotype). We find that one of these genes, krotzkopf verkehrt (kkv), encodes the Drosophila chitin synthase enzyme and that a closely linked gene, knickkopf (knk), encodes a novel protein that shows genetic interaction with the Drosophila E-cadherin, shotgun. We also demonstrate that two other known mutants, grainy head (grh) and retroactive (rtv), show the blimp phenotype when devitellinized, and we describe a new mutation, called zeppelin (zep), that shows the blimp phenotype but does not produce defects in the head cuticle as the other mutations do.
The Role of Spotlighting Procedures in Promoting Citizen Participation, Transparency, and Accountability

There is a great deal of interest in “new governance” and other approaches that tout the benefits of increasing citizen participation, and government transparency and accountability. As one scholar colorfully notes, today there is “nearly universal veneration of open government as a political idea,” making transparency “the sweet elixir of contemporary governance.” This Article examines an innovative governance mechanism that expands opportunities for public involvement in governance and is intended to enhance government transparency and accountability - the North American Commission for Environmental Cooperation (“CEC”) citizen submissions process. Because of its key features, the process is worth study in its own right. In addition, this process “continues to be a model” for U.S. regional trade agreements and warrants study for that reason as well. The Article considers the track record of the process and its prospects for the future, in addition to its possible value as a model for other citizen-driven transparency and accountability processes. The Article identifies several challenges in creating governance structures that empower citizens and make government more accountable and transparent, and offers both specific “fixes” to strengthen the CEC process in the short-term, and a conceptual framework for reconsidering the appropriate focus and structure of citizen submission processes in order to enhance their effectiveness.
CT peritoneography in evaluation of pediatric dialysis complications

Intraperitoneal contrast material with CT scanning was used to evaluate three children with multiple recurrences of peritonitis and no obvious source of infection while they were undergoing continuous-cycling peritoneal dialysis. In one child a loculus of uno-pacified dialysate was readily identified, confirming sonographic findings that suggested an inflammatory pseudocyst. In the other two children, contrast material dispersed throughout the peritoneal dialysate, suggesting that recurrent peritonitis occurred from extraperitoneal contamination. CT peritoneography is easily performed with contrast material instilled through the peritoneal dialysis catheter. Combining anatomic imaging with intraperitoneal-fluid dynamics, this technique should provide more complete evaluation of the peritoneal cavity than other imaging methods. While additional evaluation is necessary, our initial experience suggests the usefulness of CT peritoneography in excluding an intraperitoneal source of infection during long-term peritoneal dialysis.
Acoustic Travel-Time Tomography of the Atmospheric Surface Layer

Acoustic travel-time tomography of the atmospheric surface layer (ASL) is based on measurements of travel time of sound impulse propagation between different pairs of sources (speakers) and receivers (microphones), which constitute the tomography array. Then, the temperature and wind velocity fields inside the tomography array are reconstructed with inverse algorithms. Improved knowledge about these fields is important in many applications: validation and input data for atmospheric models, studies of turbulence over complex topography and heterogeneous surfaces, input data for wave propagation models, etc.© 2009 ASME
Resonance enhancement of electron-impact excitation rates for argonlike ions.

We have calculated the electron-impact excitation-rate coefficients for the 3p-3d transitions of Ar-like ions with Z=42, 54, and 63. The direct-excitation rates were evaluated with relativistic multiconfiguration target wave functions in a distorted-wave approximation. The contributions from the autoionizing resonances were calculated by the multiconfiguration Dirac-Fock method. For most transitions, autoionizing resonances are found to enhance the rate coefficients by factors of 2--3 for electron temperatures below the temperature at which peak excitation occurs. The enhancement is much less at higher temperatures.
A large coaxial Ge(Li) detector with plastic anticoincidence scintillator for activation analysis

Abstract A gamma ray spectrometer has been constructed which makes use of a Ge(Li) detector with 35 cm 3 active volume surrounded by a plastic scintillator annulus for Compton suppression. Efficiencies between 0.1 and 1 percent are obtained with resolutions between 6 and 7 keV. Compton suppression of about a factor of two is obtained.
Stochastic problems in information transfer across the plasma membrane

The surfaces of many cells are viscous fluids; consequently, most membrane proteins are able to diffuse laterally, in a more or less random fashion, with diffusion coefficients typically of order 10 −10 cm 2 /sec. If a molecule (ligand) in solution outside the cell and a protein molecule on the surface (receptor) each have two or more sites at which they can interact with one another, large, branched receptor-ligand networks can form on the cell surface by virtue of the chemical interactions that surface fluidity permits. Evidence from a variety of systems indicates that such receptor clustering plays a role in the sequence of events leading to cellular activity. This paper describes a number of mathematical problems that arise in the analysis of experiments in which clustering occurs. I begin by reviewing methods for finding the time evolution of the cluster size distribution function in terms of reaction rate constants. The methods solve an essentially infinite system of coupled nonlinear differential equations. Next, the rate constants are analyzed, the Brownian motion problems that arise in attempting to understand ligand recognition are described and relevant experimental systems are discussed. Finally the notion of ligand as a signal amplifier is introduced—an idea that emerges naturally from the requirement that receptors be clustered for a finite amount of time before a signal can be transmitted.
An International Comparison of the Association Among Literacy, Education, and Health Across the United States, Canada, Switzerland, Italy, Norway, and Bermuda: Implications for Health Disparities

The relationship between education and health is well-established, but theoretical pathways are not fully understood. Economic resources, stress, and health behaviors partially explain how education influences health, but further study is needed. Previous studies show that health literacy mediates the education-health relationship, as do general literacy skills. However, little is known whether such mediation effects are consistent across different societies. This study analyzed data from the International Assessment of Adult Literacy and Life Skills Survey conducted in Canada, the United States, Italy, Norway, Switzerland, and Bermuda to investigate the mediation effects of literacy on the education-health relationship and the degree of such mediation in different cultural contexts. Results showed that literacy skills mediated the effect of education on health in all study locations, but the degree of mediation varied. This mediation effect was particularly strong in Bermuda. This study also found that different types of literacy skills are more or less important in each study location. For example, numeracy skills in the United States and prose (reading) literacy skills in Italy were stronger predictors of health than were other literacy skills. These findings suggest a new direction for addressing health disparities: focusing on relevant types of literacy skills.
I’ve Fallen and I Can’t Get Up: Can High-Ability Students Recover From Early Mistakes in CAT?

A difficult result to interpret in Computerized Adaptive Tests (CATs) occurs when an ability estimate initially drops and then ascends continuously until the test ends, suggesting that the true ability may be higher than implied by the final estimate. This study explains why this asymmetry occurs and shows that early mistakes by high ability students can lead to considerable underestimation, even in tests with 45 items. The opposite response pattern, where low-ability students start with lucky guesses, leads to much less bias. The authors show that using Barton and Lord’s four-parameter model (4?M) and a less Lord’s four-parameter model (4?M) and a less informative prior can lower bias and root mean square error (RMSE) for high-ability students with a poor start, as the CAT algorithm ascends more quickly after initial underperformance. Results also show that the 4?M slightly outperforms a CAT in which less discriminating items are initially used. The practical implications and relevance for psychological measurement more generally are discussed.
Partial U(1)A restoration and eta enhancement in high-energy heavy-ion collisions.

We calculate the thermally averaged rates for {eta}-{pi} conversion and {eta} scattering using the Di Vecchia{endash}Veneziano and {close_quote}t Hooft models, which incorporate explicitly the U(1){sub {ital A}} anomaly. Assuming an exponential suppression of the U(1){sub {ital A}} anomaly, we also take into account the partial restoration of U(1){sub {ital A}} symmetry at high temperatures. We find that the chemical equilibrium between {eta} and {pi} breaks up considerably earlier than the thermal equilibrium. Two distinct scenarios for the {eta} freeze-out are discussed and the corresponding chemical potentials are calculated. We predict an enhancement of the thermal {eta} production as a possible signal of the partial U(1){sub {ital A}} restoration in central high-energy heavy-ion collisions. {copyright} {ital 1996 The American Physical Society.}
Impedance imaging relative to gas-liquid systems

Abstract Determining interfacial area density in two-phase, gas-liquid flows is one of the major elements impeding significant development of predictive tools based on the two-fluid model. Currently, these models require coupling of liquid and vapor at interfaces using constitutive equations which do not exist in any but the most rudimentary form. This paper describes the theory of impedance imaging of two-phase mixtures and summarizes bench-type experiments utilized in its development, testing, and feasibility evaluation.
Shape Perception: Complex Contour Representation in Visual Area V4

A recent study has put forward a physiologically plausible population model that implements a parts-based shape-coding scheme for macaque visual area V4.
RNA Unwinding by the Helicase Mtr4p and the TRAMP Complex Investigated via High-Resolution Optical Trapping

We present single-molecule high-resolution optical trapping measurements of RNA unwinding by the Ski2-like nuclear helicase Mtr4p both alone and within the Trf4/Air2/Mtr4 polyadenylation (TRAMP) complex. RNA helicases such as Mtr4p play key roles in RNA metabolism. Mtr4p is thought to assist RNA degradation by the exosome presumably by unwinding RNA structures. In addition, the TRAMP complex appends short 3′ poly(A) tails to RNA meant for degradation by the exosome. Mtr4p within the TRAMP complex plays a crucial role in regulating the polyadenylation activity, limiting the poly(A) tail length. The unwinding activity of Mtr4p is required and indeed within the TRAMP complex, Mtr4p unwinds duplex RNA 10x faster than when alone. However, the dynamic details of the RNA unwinding activity and interaction of Mtr4p and TRAMP and indeed the Ski2-like family of RNA helicases are unknown. We have performed high-resolution RNA hairpin unwinding experiments for both Mtr4p and TRAMP. We find that Mtr4p unwinds RNA duplexes in a single or multiple bursts with a mean step size of 9 base pairs. The unwinding is irreversible suggesting that Mtr4p remains stably bound after unwinding the duplex, preventing re-annealing. TRAMP unwinding experiments reveal a faster molecular recognition by the Mtr4p helicase when in complex as well as enhanced RNA duplex unwinding dynamics. Combined high-resolution trapping and fluorescence experiments underway may reveal how the competition within TRAMP between the 3′-to-5′ Mtr4p helicase and the 5′-to-3′ Trf4p polymerase is resolved dynamically.
Histochemical correlates of changes in the primate brain associated with varying environmental light conditions

Squirrel monkeys were kept in 3 groups of 2 each maintained on one of the following light schedules: 12-12 hour light/dark, continuous light, and continuous dark. The animals (one from each group) were sacrificed after a period of 81/2 and 111/2 months and histochemical techniques for some oxidative and hydrolytic enzymes were employed in cryostat section of the brains of these animals. Lactic dehydrogenase (LDH), an enzyme involved in glycolytic metabolism, showed enhanced enzyme activity compared to the other two groups in a number of areas (e.g., corpus geniculatum laterale, nucleus n. oculomotorii and trochlearis, nucleus interpeduncularis, locus coeruleus, reticular formation, cerebellar cortex, etc.). LDH showed more pronounced enzyme changes in the neuropil, whereas the neurons showed somewhat more enhanced activity in the succinic dehydrogenase preparations. Butyrylcholinesterase and simple esterase, however, did not show any difference in enzyme reaction in the three groups under study. Similarly, certain areas (e.g., colliculus superior, griseum pontis, central gray, vestibular and cochlear nuclei, choroid plexus and ependyma) did not show any enzyme difference in all the eight enzyme preparations. The epiphysis showed a decrease in monoamine oxidase activity in the constant light-exposed animals compared to the other two groups. The significance of these findings is discussed.
Hair transplantation. A three-stage approach for creating the hairline.

This article describes the use of a handy, battery-powered, thermocautery unit to cut through the nail plate when performing dermatologic surgery involving nail tissue. Thermocauterization of keratin is a simple, atraumatic method of removing portions of the nail plate, so that the underlying soft tissue may be biopsied or treated. The units are inexpensive and safe to operate
Reversed-Phase High-Pressure Liquid Chromatographic Determination of Serum Methotrexate and 7-hydroxymethotrexate

A reversed-phase high-pressure liquid chromatographic method for determining methotrexate and 7-hydroxymethotrexate in human serum is presented. A mobile phase of acetate buffer (0.2 M, pH 5.5 with 0.03 M ethylenediaminetetraacetate), methanol, and acetonitrile (85.3:8.4:6.3), passed through a μBondapak C18 column at 1.5 ml/min produced excellent resolution of sharp, symmetrical bands. An improved extraction process, using a sample preparation cartridge, resulted in analytical recoveries in excess of 90% for methotrexate and 70% for 7-hydroxymethotrexate, permitting the determination of serum concentrations of 2.20 and 2.13 × 10−7 M, respectively, using only 200 μ of serum. UV detection at 313 nm provided adequate sensitivity for each component. While the reproducibility for 7-hydroxymethotrexate was approximately equal to previous methods, that for methotrexate was greatly improved. Serum methotrexate data at selected time points following high dose methotrexate therapy are presented.
Limits to economic growth as shown by a computable general equilibrium model

Abstract Economic growth is distinguished from commercial growth and is defined in this article as the growth of the value a society puts in monetary terms on all commercial and non-commercial goods and values it possesses during a certain period. A computable general equilibrium model is used to show the impact of changes in the endowments, preferences and production possibilities on economic income, which in the model comprises all wealth. Besides land with its natural resources and labor, energy is the key endowment to drive an economy. The model leads in an intuitive way to the following conclusions: (1) Societies should start to use appropriate indicators for true economic growth, rather than just for commercial growth as measured by gross national product. (2) All types of economic growth are limited, no matter if based on endowment growth, production efficiency growth, or changes in preferences. (3) Economic growth should be oriented more towards increasing production efficiency and less towards using more natural resources. (4) Human population growth puts at risk the possibilities for average economic growth per person. (5) We should get better prepared to use solar energy in the future. (6) Besides economic growth, there exists pure utility growth, which is not measurable in monetary terms; it includes much of scientific progress in the long run and is of great importance even though it cannot be included in an indicator of economic growth.
5-HT1B autoreceptor regulation of serotonin transporter activity in synaptosomes

Serotonin-1B (5-HT(1B) ) autoreceptors are located in serotonin (5-HT) terminals, along with serotonin transporters (SERT), and play a critical role in autoregulation of serotonergic neurotransmission and are implicated in disorders of serotonergic function, particularly emotional regulation. SERT modulates serotonergic neurotransmission by high-affinity reuptake of 5-HT. Alterations in SERT activity are associated with increased risk for depression and anxiety. Several neurotransmitter receptors are known to regulate SERT K(m) and V(max) , and previous work suggests that 5-HT(1B) autoreceptors may regulate 5-HT reuptake, in addition to modulating 5-HT release and synthesis. We used rotating disk electrode voltammetry to investigate 5-HT(1B) autoreceptor regulation of SERT-mediated 5-HT uptake into synaptosomes. The selective 5-HT(1B) antagonist SB224289 decreased SERT activity in synaptosomes prepared from wild-type but not 5-HT(1B) knockout mice, whereas SERT uptake was enhanced after pretreatment with the selective 5-HT(1B) agonist CP94253. Furthermore, SERT activity varies as a function of 5-HT(1B) receptor expression-specifically, genetic deletion of 5-HT(1B) decreased SERT function, while viral-mediated overexpression of 5-HT(1B) autoreceptors in rat raphe neurons increased SERT activity in rat hippocampal synaptosomes. Considered collectively, these results provide evidence that 5-HT(1B) autoreceptors regulate SERT activity. Because SERT clearance rate varies as a function of 5-HT(1B) autoreceptor expression levels and is modulated by both activation and inhibition of 5-HT(1B) autoreceptors, this dynamic interaction may be an important mechanism of serotonin autoregulation with therapeutic implications.
Ductile fracture in spheroidized 1520 steel

Abstract Ductile fracture was investigated in a spheroidized steel, similar to AISI 1520, which contained negligible amounts of P and S. The detailed substeps of the ductile fracture process were characterized by careful sectioning studies. It was found that 1. (i) void initiation appeared to be controlled by a criterion involving stress, 2. (ii) void growth was predominantly affected by plastic strain, 3. (iii) additional strain was needed to arrive at final fracture even after the void coalescence stages, comprising microvoid coalescence and macrovoid coalescence, had occurred and 4. (iv) the central crack growth in tension mainly depended on the strain concentration at the crack tip. The effect of localized deformation on fracture could not play a role in axisymmetric tension, due to a high critical strain for shear band formation.
The giant apocrine hidrocystoma

We report a patient with a large apocrine hidrocystoma. These tumors are almost always under 10 mm in diameter. In this 40-year-old man the tumor measured 20 mm. Apocrine hidrocystoma must be considered when evaluating a patient with a large cystic lesion of the face. Surgical management is similar to that of other benign cystic lesions of this region.
Resonance Processes in e – H2 Collisions: Dissociative Attachment and Dissociation from Vibrationally and Rotationally Excited States

We summarize theoretical studies of dissociative electron attachment to rovibrationally excited H2 molecules by comparing results of earlier local calculations with the results of more recent nonlocal complex potential calculations. The extension of the resonance theory to the near-threshold resonant dissociation is discussed and results are shown for dissociation from vibrationally excited states. Contributions from two negative-ion resonances, 2Σu+ shape resonance and 2Σg+ Feshbach resonance, are analysed. We also demonstrate the isotope effect by presenting the peak values of the dissociative attachment cross section for all five isotopic substitutes of H2.
The importance of localizing neocortical-amygdaloid disconnections in behavioral investigations.

Abstract Wegener has reported that visual and auditory discrimination deficits result from bilateral ablations of the anterior supratemporal plane cortex in monkeys. Another possible explanation which can be considered, however, is that the visual and auditory deficits may be attributable to the bilateral while matter damage associated with these ablations. This report describes the anatomical locations of the white matter fiber pathways that connect the anterior temporal neocortical visual and auditory association areas to the amygdala. It further discusses how supratemporal plane ablations may invade these white matter pathways and produce behavioral deficits due to visual and auditory cortical-limbic disconnections.
Heterogeneity of microvascular dysfunction in women with chest pain not attributable to coronary artery disease: implications for clinical practice.

Abstract Background Women with chest pain in the absence of obstructive coronary artery disease (CAD) frequently have coronary microvascular dysfunction and inducible myocardial ischemia. Microvascular dysfunction is commonly diagnosed by demonstrating abnormal flow reserve in a single coronary artery during angiography. Therefore, diagnostic accuracy is dependent on homogeneity of microvascular dysfunction in the myocardium. Methods In the Women's Ischemia Syndrome Evaluation (WISE), 34 women with chest pain and no significant CAD and 9 female control subjects underwent 13 N-NH 3 positron emission tomography to measure adenosine-induced changes in myocardial perfusion (ie, coronary flow reserve [CFR]). Flow reserve was correlated among the left anterior descending (LAD), circumflex (LCx), and right (RCA) coronary artery distributions. Results The mean CFR in the LAD, LCx, and RCA was 2.85 ± 1.35, 2.58 ± 0.94, and 3.24 ± 1.42, respectively. Concordance in the classification of microvascular function as normal (CFR ≥2.5) versus abnormal was present in the LAD and RCA, LAD and LCx, and RCA and LCx distributions in only 71.8%, 66.7%, and 61.6% of patients, respectively. There was a modest degree of correlation of CFR between the LAD and RCA ( r = 0.79, P r = 0.61, P r = 0.57, P Conclusion Substantial discordance of classification of microvascular function among coronary artery distributions in women with chest pain and no CAD suggests that microvascular dysfunction is distributed heterogeneously in the myocardium. Assessment of CFR in a single coronary artery during cardiac catheterization may not provide an accurate assessment of the coronary microcirculation in women with chest pain not attributable to CAD. (Am Heart J 2003;145:628-35.)
Clinicopathologic effects of cancer chemotherapeutic agents on human buccal mucosa

Abstract Specimens of buccal mucosa obtained at autopsy from 216 patients were examined for histopathologic alterations. Atrophic oral epithelium was found in thirty cases. A retrospective study of the hospital records revealed that thirteen of these latter patients had been on a cancer chemotherapeutic regimen prior to death. There was a significantly higher incidence of atrophy in the chemotherapy group (p
Severe carpal and tarsal shearing injuries treated with an immediate arthrodesis in seven dogs.

The medical records of seven dogs with severe, grade 3, open shearing wounds of the carpus or tarsus that were treated with an immediate arthrodesis were reviewed. Six dogs were managed with a transarticular external skeletal fixator (ESF), and one dog was treated with plate fixation. The soft tissues were managed simultaneously along with the definitive joint stabilization in all cases. Minor complications occurred in four dogs: one dog that required a skin graft, one dog in which a skin graft was recommended but not performed, one dog in which a secondary skin closure was performed, and one dog in which a delayed cancellous bone graft was placed. Major complications occurred in three dogs: two dogs that required restabilization of the arthrodesis and one dog that required implant (i.e., plate) removal due to infection. All dogs healed with acceptable functional and cosmetic results. Further long-term evaluation of five dogs revealed that all but one dog had either excellent or good functional outcomes, and the remaining dog had a fair outcome. Similarly, five dogs had either excellent or good cosmetic outcomes, with the remaining dog having a fair outcome. All owners were very satisfied with the overall results. This clinical study demonstrated that an immediate, definitive management technique, in which bone fusion and wound management are undertaken as simultaneous objectives, is a viable technique of managing severe periarticular shearing injuries. Transarticular stabilization with an ESF is the technique recommended.
Physical activity among older Mexican American women

Theories of stage of readiness for change and self-efficacy guided this investigation of (a) performance of habitual physical activity (daily activity and leisure/sport activity), (b) preference for leisure physical activities, and (c) relationships of age, stage of readiness for exercise, and exercise self-efficacy with habitual physical activity. The sample consisted of 71 community-residing Mexican American women aged 60–87 years. Fifty-six women reported performing at least one leisure/sport activity; the most frequent was walking, reported by 47 women. Fifty-three women stated that walking was their preferred leisure activity. Age, self-efficacy, and stage of readiness accounted for 27% of the variance in daily activity and 32% of the variance in leisure/sport activity. These findings suggest that stage of readiness for change and self-efficacy theories are useful for this population. © 2000 John Wiley & Sons, Inc. Res Nurs Health 23:383–392, 2000.
EXPERIMENTAL STUDY OF STARK BROADENED N II LINES FROM STATES OF HIGH ORBITAL ANGULAR MOMENTUM

Abstract In this paper, we report experimental electron impact widths for six spectral lines belonging to 3d-4f transitions of singly ionized nitrogen. Line profiles were measured in a low pressure pulsed arc. An electron density in the range 5.9–7.5 × 1022m-3 was determined from the Stark width of the He II 4686 A line, while electron temperatures of 28,300–32,300 K were measured using relative intensities of O II impurity lines. Comparison with semiempirical theoretical results does not resolve which coupling scheme, LS or LK, is better to describe atomic states in Stark broadening calculations of certain N II lines.
Evidence for conformational isomerism. II. Synthesis of 1-alkyl-2-carboazetidines using organolithium reagents†

Treatment of 1-alkylazetidine-2-carboxylic acids with several organolithium reagents leads to the corresponding 1-alkyl-2-carboazetidines in near quantitative yield. Additional evidence is presented for conformational isomerism in the title compounds on the basis of infrared carbonyl stretching frequencies.
Dimethyldioctadecylammonium clay-xylene vapor interactions

Abstract Adsorption by dimethyldioctadecylammonium montmorillonite and hectorite of the xylene isomers was investigated. X-ray diffraction data revealed that expansion occurs in two stages. In each stage basal spacing varies linearly with free energy. Force constants were determined. A transition in force constants occurs at about 31 A and is associated with the adsorption of approximately 41 mg/g of xylene. Compaction of the crystallites during desorption shows significant hysteresis. It was observed that the interlamellar porosity of these two organoclays is variable. Differences in the isosteric heats between vapor-conditioned and fresh organoclay and between the montmorillonite and hectorite mineral derivatives as a function of amount of xylene adsorbed appeared to be linear. This difference analysis suggested that the intensity of the xylene-hydrocarbon chain interaction was in the order ortho > meta > para. It also disclosed an inherent difference between the two mineral derivatives which appears to be related to differences in the external aggregate structures of the two organoclays. The kinetics of adsorption showed that the rate of intercalation occurs in two stages. The transition in rate behavior occurs at the same point as the force constant transition, at approximately 41 mg/g of xylene. Intercalation proceeds kinetically in the order meta > ortho > para, an order different from that shown in adsorption intensity.
ISOLATION AND ANALYSIS OF RNA FORMED BY CELL-FREE EXTRACTS FROM TOBACCO LEAVES.

Abstract The RNA-like product obtained by incubation of ATP, GTP, UTP, and CTP with a cell-free extract from tobacco leaves has been purified by phenol extraction and passage through Sephadex. When either [α- 32 P]ATP or [α- 32 P]GTP was included in the reaction mixture the major portion of the incorporated counts remained associated with the RNA during purification. In both cases, alkaline hydrolysis of this purified, labeled product yielded AMP, GMP, CMP, and UMP all of which were 32 P-labeled. This provides direct evidence that the labeled product of the reaction contains all four nucleotides linked by interribonucleotide bonds to form a true RNA.
β-Lactam-Resistant Enterobacter Bacteremia in Febrile Neutropenic Patients Receiving Monotherapy

Bacteremia with resistant Enterobacter species has been reported in febrile, neutropenic cancer patients receiving beta-lactam antibiotics. To assess the relationship between enterobacter bacteremia and ceftazidime monotherapy, medical records were reviewed and isolates were tested from 16 neutropenic and 35 nonneutropenic patients with Enterobacter bacteremia. Fifteen isolates from the neutropenic patients were resistant to extended spectrum cephalosporins; only 12 of 35 isolates from the nonneutropenic patients were resistant to Enterobacter species. The neutropenic patients also had more beta-lactam therapy, both immediately before bacteremia and in the preceding year, than did nonneutropenic patients. Prior beta-lactam antibiotic exposure may predispose neutropenic patients to develop resistant Enterobacter bacteremia.
Juvenile nasopharyngeal angiofibroma: an ultrastructural study.

Four clinically and histologically typical juvenile nasopharyngeal angiofibromas were examined by electron microscopy. An original tumor, first, fifth and sixth recurrence, respectively, were studied. The stromal cells of the early stage tumors (original and first recurrence) contained lobulated nuclei, large intranuclear inclusions, variable amounts of rough endoplasmic reticulum (RER) and thin filaments, hemidesmosomes, focal basal lamina and prominent pinocytotic vesicles. In the later (fifth and sixth recurrence) stage tumors, the nuclei often had serrated margins and smaller inclusions. The cytoplasm contained dilated cisternae of RER and numerous thin filaments with dense bodies. Hemidesmosomes and pinocytosis were diminished; no basal lamina was observed. These observations indicate that the stromal cell of this tumor undergoes some structural modulation between its early and late stages. The nuclear granules appear to diminish in size with time. The cells in both stages possess features common to both fibroblasts and smooth muscle cells. Such a hybridized mesenchymal cell, i.e. “myofibroblast”, has been previously described for other fibroproliferative lesions, although its presence in this tumor is of uncertain significance. Additional electron microscopic studies of fibrous and soft tissue lesions are needed to further characterize the prevalence and perhaps the origin of the myofibroblast.
Sound Studies Meets Deaf Studies

ABSTRACTSound studies and Deaf studies may seem at first impression to operate in worlds apart. We argue in this article, however, that similar renderings of hearing, deafness, and seeing as ideal types—and as often essentialized sensory modes—make it possible to read differences between Sound studies and Deaf studies as sites of possible articulation. We direct attention to four zones of productive overlap, attending to how sound is inferred in deaf and Deaf practice, how reimagining sound in the register of low-frequency vibration can upend deafhearing dichotomies, how “deaf futurists” champion cyborg sound, and how signing and other non-spoken communicative practices might undo phonocentric models of speech. Sound studies and Deaf studies emerge as fields with much to offer one another epistemologically, theoretically, and practically.
Treatment of chronic cryptosporidial infection with orally administered human serum immune globulin.

8. Hyman CL, Augenbraun MH, Roblin PM, Schachter J, Hammerschlag M. Asymptomatic infection with Chlamydia pneumoniae. Presented at the Oct. 21-24, 1990, meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy, Atlanta, Ga. 9. Grayston JT, Kuo CC, Wang SP, Altman J. A new Chlamydia psittaci strain, TWAR, isolated in acute respiratory tract infection. N Engl J Med 1986;315:161-8. 10. Li D, Daling JR, Wang SP, Grayston JT. Evidence that Chlamydia pneumoniae, strain TWAR, is not sexually transmitted. J Infect Dis 1989;160:328-31. 11. Porder K, Sanchez N, Roblin PM, McHugh M, Hammerschlag M R. Lack of specificity of chlamydiazyme for detection of vaginal chlamydial infection in prepubertal girls. Pediatr Infect Dis J 1989;8:358-60. 12. Hammerschlag MR, Rettig P J, Shields ME. False positive results with the use of chlamydial antigen detection tests in the evaluation of suspected sexual abuse in children. Pediatr Infect Dis J 1988;7:11-4. 13. Dorian K J, Holtzhauer F, Myers WC, Moser JM, Halpin TJ. False-positive results with the use of chlamydia tests in the evaluation of suspected sexual abuse: Ohio, 1990. MMWR 1991;39:932-5.
Gendering unemployment in postsocialist Germany: ‘what I do is work, even if it's not paid’

This article uses feminist theories of the family to examine women's unemployment in the early years of German postsocialism. It is based on qualitative fieldwork, including 80 in-depth interviews, conducted in three cities in the formerly socialist region of Germany. In this article, three cases of couples coping with a wife's unemployment are analyzed in terms of micro-processes of negotiating work-family balance, redefining employment and domesticity, and reconstructing gendered identities. The central argument is that a couple's stance on emerging market institutions shaped how they re-negotiated their gender division of labor during postsocialism.
The Preparation of Polymer/Silver Nanocomposites and Application as an Antibacterial Material

An elegant and facile route for the preparation of polymer/silver nanocomposites for polymers having solubility in organic solvents has been developed. Aqueous colloidal solution of nano-silver has been used as the source of nano-silver particles. Nano-silver particles were transferred to the poly(methyl acrylate) (PMA) solution in chloroform using phase transfer methodology. Separation of the aqueous phase gave solution of nano-silver/PMA in chloroform. The solution was coated onto glass substrate providing uniform film of antibacterial PMA/silver nanocomposite, thus exhibiting its potential application as a coating material. The same methodology has been successfully extended to prepare polyether sulphone/silver nanocomposites.
Back surgery--who needs it?

Dr. Richard Deyo writes that despite assertions that surgery is only a last resort or is used more selectively than in the past, the rate of spine surgery has steadily increased in recent decades. ...
Indirect techniques in nuclear astrophysics: The ANC method

Asymptotic normalization coefficients (ANCs) have proven to be useful for determining reaction rates of interest in nuclear astrophysics. ANCs, which provide the normalization of the tail of the overlap function, determine S factors for direct capture reactions at astrophysical energies. During the past eight years, many ANCs have been measured by peripheral transfer reactions. Following an introduction to ANCs, recent experiments are briefly described. The astrophysical implications of some of these measurements are discussed and a future outlook for ANC measurements with radioactive beams is given.
Proactive versus Retroactive Interference in Recognition Memory

Summary A recognition task situation was analyzed in terms of the individual items in an attempt to formulate a more comprehensive explanatory concept re the controlling effects of proactive vs. retroactive interferences, for which both evidence and interpretations have been inconsistent. By manipulating sublists, proactive and retroactive events were systematically varied, with three types of materials: CVC nonsense syllables, two-digit numbers, and words in two experiments. A total of 120 male and female undergraduates participated as Ss. Proactive study events generated quite limited effects, if any. In contrast, both retroactive study and test events controlled recognition performances. The current results, as well as previous inconsistent ones, can be accommodated within a single theoretical framework with focus on the retention interval.
The transmuted visual pigments of geckos

The visual pigments of geckos, like the visual cells, appear to be unique in certain respects and to pose a number of important questions to visual science. The gecko photopigments are characterized by a broad spectral distribution from close to 500 nm, in some species, to the region of 530 nm in other species. These pigments appear to be especially sensitive to NH2OH and are destroyed by this reagent in the dark and at 5°C, at concentrations which leave the usual rhodopsins unaffected. In some species the photopigment appears to be susceptible, in part at least, to treatment of the retina with potassium alum prior to extraction. In these respects the gecko pigments appear to resemble iodopsin from the chicken retina. A singular property of the gecko photopigments is their extreme lability to mild temperature increases above 5°C. Up to about 30°C the thermal Bleaching of pigment is rapidly and often completely reversed when the temperature is returned to 5°C. This thermal lability is in sharp contrast to the behavior of frog rhodopsin which is unaffected by temperatures up to 35°C, at least in the time required to bleach the gecko pigments to equilibrium levels. The difference in action of heat and light in bleaching visual pigments is especially well illustrated with the gecko pigments, light acting by isomerizing the chromophore, heat by altering the conformation of the protein without such isomerization. a unique product, as yet unidentified, appears to result from the action of mild temperatures on the gecko pigments. The nature of this product and what it may reveal about the chemical structure of visual pigments are problems for the future.
Viscoelastic Properties of Living Human Brain by Local Frequency Estimation Applied to Distortional Wave Fields

The use of magnetic resonance imaging (MRI) to characterize the biomechanical material properties of tissue in vivo is an emerging application. Local frequency estimation (LFE) [1] has been used to locally extract the wavenumber κ from displacement wave fields in order to estimate the elastic shear modulus via the well-known phase velocity relation [2,3]. LFE-based inversion is attractive because it allows material parameters to be estimated without explicitly invoking the equations of motion, thus obviating the need to numerically compute the Laplacian. In this study, viscoelastic properties of brain tissue at multiple frequencies were obtained by local frequency estimation (LFE) applied to distortional wave fields. This avoids artifacts from the presence of unmodeled longitudinal waves. By use of the equation describing planar distortional wave propagation in a lossy medium, the viscoelastic shear moduli were approximated.© 2012 ASME
Electrical properties of hard materials

Abstract Some materials are as hard as ceramics but contain conduction electrons i.e., “metallic ceramics”. The ones described are monocarbides of Group IV and V transition metals: TiC, ZrC, HfC, and VC, NbC, TaC, and one of Group VI: WC. The IV and V materials can be useful because of certain properties – high melting points, high hardness, low diffusion rates of metal and carbon, little change in resistivity at high temperatures, low electromigration, corrosion resistance; the applications can be to microelectronic devices and to high-temperature switches and resistors. One reason for the saturation of this electrical resistivity at high temperatures is a large residual resistivity due to scattering of conduction electrons by random carbon vacancies (point defects) in these non-stoichiometric compounds, e.g., TiC x , where x represents the carbon-to-metal ratio, and 1-x represents the carbon vacancy concentration, which can range from 3% to 50%. A second reason is a parallel resistor effect due to interband scattering of these electrons in the complex electron band structure. But specific compositions of these non-stoichiometric compounds can shift to periodic structures and eliminate the residual resistivity, thus increasing the temperature dependence at low temperatures but not at high temperatures because of interband scattering. WC, which is stoichiometric, has a near zero residual resistivity and a strong temperature dependence.
Oxygen consumption following exercise of moderate intensity and duration

To study the effects of exercise intensity and duration on excess postexercise oxygen consumption (EPOC), 8 men [age= 27.6 (SD 3.8) years, VO2max = 46.1 (SD 8.5) ml min−1 kg−1] performed four randomly assigned cycle-ergometer tests (20 min at 60% VO2max, 40 min at 60% VO2max, 20 min at 70% VO2max, and 40 min at 70% VO2max). O2 uptake, heart rate and rectal temperature were measured before, during, and for 1 h following the exercise tests. Blood for plasma lactate measurements was obtained via cannulae before, and at selected times, during and following exercise. VO2 rapidly declined to preexercise levels following each of the four testing sessions, and there were no differences in EPOC between the sessions. Blood lactate and rectal temperature increased (P<0.05) with exercise, but had returned to preexercise levels by 40 min of recovery. The results indicate that VO2 returned to resting levels within 40 min after the end of exercise, regardless of the intensity (60% and 70% VO2max or duration (20 min and 40 min) of the exercise, in men with a moderate aerobic fitness level.
Morbidity associated with anomalous origin of the right coronary artery from the left sinus of Valsalva

Anomalies of the coronary arteries occur infrequently, but can have major clinical consequences. Many reports have described an association between sudden death and origin of the left coronary artery from the right sinus of Valsalva, but origin of the right coronary artery from the left sinus of Valsalva is thought to be benign. Herein, we describe a patient in whom anomalous origin of the right coronary artery from the left sinus of Valsalva was associated with significant cardiovascular morbidity. A 25-year-old man developed complete heart block and myocardial infarction in the distribution of a dominant anomalous right coronary artery free of atherosclerotic lesions. Systolic compression at the origin of the anomalous artery was demonstrated. The left coronary artery was normal. We conclude that anomalous origin of the right coronary artery from the left sinus of Valsalva may be associated with significant cardiovascular morbidity in the absence of atherosclerosis.
INCREASED INTESTINAL ELIMINATION OF N'-METHYLNICOTINAMIDE IN IRRADIATED RATS.

SummaryThe influence of 525 r whole-body x-irradiation on the intestinal absorption and elimination of N′-methylnicotinamide has been investigated. This material does not appear to be absorbed to any appreciable extent by the irradiated animal. A significant increase in elimination of this metabolite via the intestinal tract was found after irradiation, and the increase was maintained even when histological evidence of tissue repair was observed. The greatest increases in elimination were seen on days 3 and 5. The evidence presented seems to indicate that the pyridine nucleotide co-enzymes of the liver are involved in the increased intestinal elimination of N′-methylnicotinamide by the irradiated animal. This metabolite is excreted not only by the urinary tract but via the intestinal tract as well.
Vector Model for Indirect Proton Hyperfine Interactions in π-Electron Radicals

Significant information on unpaired electron distributions in molecules, liquids, and solids can sometimes be obtained from magnetic resonance studies of electron-nucleus hyperfine interactions. A particularly important problem in this field involves the proton hyperfine interactions that have been observed in the electron magnetic resonance spectra of a large number of aromatic radicals in solution [1-3]. The problem concerns the theoretical basis for a proposal that the observed hyperfine splitting aN due to aromatic proton N in an aromatic radical can be used to estimate the unpaired spin density ρN at carbon atom N to which proton N is attached, according to the equation [2,4-6] aN = QρN. (1) A semiempirical value of Q derived from observed splittings aN and theoretically calculated spin densities ρN is -30 ± 5 gauss, or -85 ± 15 Mc [2]. Equation (1) has been derived recently using molecular orbital theory with arbitrary π-π configuration interaction [6]. We show here how the simple proportionality in equation (1) may be derived using the Dirac vector model.