cssi/SciSciGPT-SciSciNet huggingface dataset:
Assessment of erythrocyte morphologic abnormalities in mallards with experimentally induced zinc toxicosis

OBJECTIVE To describe and quantify morphologic abnormalities in RBCs of mallards (Anas platyrhynchos) with experimentally induced zinc toxicosis. ANIMALS 120 female mallards. PROCEDURE Farm-raised mallards (6 to 8 months old) were used in the study. On day 0, 60 ducks received shot pellets orally by gavage (mean dose of zinc, 0.97 g); another 60 ducks underwent the same procedure without administration of pellets. On day 15, Romanowsky-stained blood smears were prepared from 53 control and 45 zinc-treated ducks (smears were examined retrospectively). In each smear, 200 RBCs were examined and numbers of erythrocytes with abnormal size, shape, or color were expressed as a percentage. Results were compared with PCV values and zinc dose. RESULTS Mean PCV value was lower in all zinc-treated ducks, compared with control ducks, and was lower in zinc-treated ducks that died or were euthanatized before day 30 because of severe clinical disease, compared with those that survived. Zinc-treated ducks that survived had a high percentage of polychromatophilic RBCs, and those that that died before day 30 had high percentages of hypochromic RBCs, fusiform RBCs, and RBC nuclear abnormalities. There was no correlation between PCV value or RBC morphologic abnormalities and dose of zinc. CONCLUSIONS AND CLINICAL RELEVANCE In ducks with severe zinc-induced hemolysis, findings indicated that functional iron deficiency may impair the effectiveness of the erythroid regenerative response and contribute to death. Erythrocyte nuclear abnormalities were consistent with mild dyserythropoiesis. These findings may be applicable to effects of other metal toxicoses and regenerative anemias in birds.
The role of the individual in social dynamics

The mathematical theories of social dynamics developed previously are deterministic and leave no room for the effects of single “exceptional” individuals. They all, however, lead to the existence of instability points and threshold phenomena. It is shown that in the neighborhood of such instability points, exceptional individuals, who appear rarely, can appreciablyadvance orretard the moment at which the instability is reached and at which a sudden change in the society occurs. Such individuals, however, do not eitherprevent orcause the instability, or the change, to occur. The indeterminacy introduced by “rare” individuals into the time course of social change is inversely proportional to the rate of social change.
Effect of reference number on magnitude estimation

The psychophysical function obtained by the method of magnitude estimation was influenced by the reference number (modulus) assigned to a “standard” line and the position of this standard in the range of comparison stimuli. Data from two experiments with judgments of apparent length of lines show how both variables systematically affect the slope of the power function. AllowingO to choose his own reference numbers, even though these numbers varied among as, tended to produce less variability in slope than ifE imposed fixed reference numbers forO to use.
Growing a Carbon Nanotube Atom by Atom: "And Yet It Does Turn"

We use field emission microscopy (FEM) to observe directly the growths of individual carbon nanotubes (CNTs) from the nucleation stage and discover that the CNTs often rotate axially during growth, thus supporting a recently proposed “screw-dislocation-like” (SDL) model. One particularly revealing case is emphasized here in which the CNT turned ∼180 times during its 11 min growth. Even more remarkable is the frame-by-frame analysis of the video which shows that the rotation proceeds by discrete steps with about ∼24 per rotation, half the number of atoms on the circumferences of common single wall carbon nanotubes (SWNTs). The conclusion is that we directly observed the SDL growth of a SWNT one carbon dimer at a time. This observation should aid researchers to precisely understand and control the growth of SWNTs.
Regeneration as an application of gastropod neural plasticity.

Gastropod research is providing many insights into mechanisms of neural regeneration. These observations were made possible by the pioneering work of individuals who described the nervous systems of gastropods, mapped prominent neurons and determined their roles and connections, and developed the techniques for culturing them. This information has allowed questions about injury responses, target selection, and pathway cues to be explored at the level of individually identified neurons. Because of gastropod studies, more is known about axon sealing, growth cone formation and behavior, signals that travel from the site of axotomy to the soma, and the second messengers that are activated there. The responses in neurons and non-neuronal cells during neural development and injury are coordinated by chemical messenger systems that are highly conserved, including neurotransmitters, cytokines, and neurotrophins. The nervous system is modified in learning paradigms by some of the same messenger systems activated by injury, because learning and injury both challenge neurons to change. The conservation of basic mechanisms that coordinate neuronal plasticity allows us to approach basic questions in relatively simple nervous systems with reasonable confidence that the findings will be relevant for other nervous systems, including possible applications to the mammalian nervous system. Microsc. Res. Tech. 49:579–588, 2000. © 2000 Wiley-Liss, Inc.
The characterization of sphingolipids of oligodendroglia from calf brain.

Abstract— Purified oligodendroglia isolated from bovine brain white matter were found to contain, in addition to galactosylceramide, sulfatide and sphingomyelin, significant quantities of glucosylcerai-mide, dihexosylceramide and esterified galactosylceramide. These sphingolipids were isolated and quan-titated and their fatty acid and long chain base patterns compared with those from sphingolipids isolated from bovine myelin, white matter and gray matter. The minor glycosphingolipids, glucosylceramide, dihexosylceramide and esterified galactosylceramide, constituted a higher percentage of glial lipids than of myelin lipids. Glucosylceramide accounted for 12% of the total glial monohexosylceramide fraction and 0.8% of total lipids; dihexosylceramide was 0.9% of total glial lipids. Both of these lipids had small quantities of α-hydroxy fatty acids. The unsubstituted fatty acids of glucosylceramide were mostly short chain (16 and 18 carbons) and were different from those of the dihexosylceramides which were a mixture of short and long chain. The hydroxy acids of each of these lipids were, however, similar and resembled those of galactosylceramide. The fatty acid patterns of galactosylceramide, sulfatide and sphingomyelin from glial cells resembled those of the corresponding lipids from myelin and white matter. The amide-linked acids of esterified galactosylceramide contained both unsubstituted and α-hydroxy chains. Their patterns were not identical to those of galactosylceramide, but were similar in all brain fractions. With the exception of sphingomyelin and dihexosylceramide, which contained small amounts of C20-sphingosine, all sphingolipids analyzed contained mostly sphingosine and dihydrosphingosine. We conclude that the distribution of sphingolipids in the oligodendroglia is characteristic, but the lipophilic residues of these lipids are not cell-specific.
Pion Photoproduction at Backward Angles Near the Second Nucleon-Pion Resonance

An experiment is described in which photons with energies of 500 to 820 Mev strike a liquid hydrogen target. The center-of-mass differential cross sections for pi /sup +/ photoproduction from the hydrogen are measured at laboratory angles of 135 and 180 deg for various photon energies. Differences between the photoproduction resonance peaks and pi /sup -/ -p total cross sections are discussed, and conclusions are suggested as to the existence of a T = 1/2 resonant state in the pion-nucleon interaction about 320 Mev center-ofmass above the J = 3/2, T = 3/2 resonance. (T.F.H.)
Of organelles and octagons: what do preservice secondary teachers learn from interdisciplinary teaching?

Abstract This study examined the impact of an interdisciplinary teaching project on the learning of preservice secondary teachers enrolled in a graduate-level, year-long teacher education program. Data were gathered from four successive cohorts of students. Principal data sources were questionnaires ( N =131), field notes from classroom observations, and preservice teachers’ oral and written reflections on the project. The study provided evidence that preservice secondary teachers can successfully create and implement interdisciplinary curriculum and are quite positive about the experience. Through this project, preservice teachers learned from one another, learned about others’ subject areas, learned about students, and experienced the spectrum of rewards and challenges that come from working with others.
Novel optoacoustic system for noninvasive continuous monitoring of cerebral venous blood oxygenation

Traumatic brain injury (TBI) and spinal cord injury are a major cause of death for individuals under 50 years of age. In the USA alone, 150,000 patients per year suffer moderate or severe TBI. Moreover, TBI is a major cause of combatrelated death. Monitoring of cerebral venous blood oxygenation is critically important for management of TBI patients because cerebral venous blood oxygenation below 50% results in death or severe neurologic complications. At present, there is no technique for noninvasive, accurate monitoring of this clinically important variable. We proposed to use optoacoustic technique for noninvasive monitoring of cerebral venous blood oxygenation by probing cerebral veins such as the superior sagittal sinus (SSS) and validated it in animal studies. In this work, we developed a novel, medical grade optoacoustic system for continuous, real-time cerebral venous blood oxygenation monitoring and tested it in human subjects at normal conditions and during hyperventilation to simulate changes that may occur in patients with TBI. We designed and built a highly-sensitive optoacoustic probe for SSS signal detection. Continuous measurements were performed in the near infrared spectral range and the SSS oxygenation absolute values were automatically calculated in real time using a special algorithm developed by our group. Continuous measurements performed at normal conditions and during hyperventilation demonstrated that hyperventilation resulted in approximately 12% decrease of cerebral venous blood oxygenation.
Frontal lobe of children with schizophrenia spectrum disorders: A proton magnetic resonance spectroscopic study

Background: Schizophrenia is commonly considered a neurodevelopmental disorder. Our aim was to determine whether the proton magnetic resonance spectroscopic (1H-MRS) changes seen in adults with schizophrenia are displayed in children at risk for developing schizophrenia. Methods: Children with symptoms of schizophrenia-spectrum disorders (n = 16; mean age = 132 months) and a comparison group (n = 12; mean age 130 months) took part in a 1H-MRS study of the left frontal lobe. Areas of peaks from N-acetylaspartate (NAA), choline (Cho), and creatine (Cre) were determined and ratios of NAA/Cre and Cho/Cre calculated and compared between groups. Results: The mean ratio of NAA/Cre was significantly lower in schizophrenia-spectrum subjects than the comparison group (1.67 vs. 1.92; p < .05). Medication status did not affect results in schizophrenia-spectrum subjects. Conclusions: Our findings suggest that the metabolic changes associated with adult schizophrenia are observed in children with some or all of the symptoms of schizophrenia, supporting a neurodevelopmental theory for schizophrenia.
The Supreme Court and Progressivism: Bickel and Schmidt's History of the Supreme Court

During the early twentieth century the Progressives grappled with issues that continue to confront Americans today. The Supreme Court was central to the Progressive Era's response to big business, race relations, and environmental conservation; and the interplay between Progressivism and the Court shaped the nation's experience with these issues throughout the entire century.' In The Judiciary and Responsible Government, 1910-1921, Alexander M. Bickel and Benno C. Schmidt make an invaluable contribution to the study of the Supreme Court during the Progressive Era. In addition to a useful synthesis of wide-ranging primary and secondary sources, the authors raise important interpretive questions concerning the role of the Court within the Progressive Movement. Above all Bickel and Schmidt consider the extent to which the Court during a crucial period resisted or facilitated the development of socially-responsive government.2 Views of the Court's relationship to Progressivism have paralleled the varied interpretations of Progressivism itself. Most current scholarship rejects the textbook image of Progressives as crusading reformers. This work places the Progressive Movement within the broader organizational response to industrialization and managerial capitalism emerging during the late nineteenth and early twentieth century. There is considerable disagreement, however, about whether the organizational transformation repre-
Phenobarbital withdrawal and behavioral disruption in the rat.

Abstract Rats given 70 mg/kg phenobarbital for 15 days after learning a locomotor response show only gradual improvement in responding when the phenobarbital is withdrawn. A 5 day delay without practice resulted in very similar improvement as is gained by practice. This indicates a spontaneous diminution of a withdrawal effect which retards behavior. Comparable findings were obtained during the treatment period itself indicating an evolution of the response contingent upon the response to the drug. Other reported experiments employed training under the influence of phenobarbital. One experiment found insignificant improvement in responding after a 7 day delay as compared with no delay. The final experiment found marked improvement in responding after 7 and 30 day delays as compared with no delay. This latter result suggests that there is a time dependent factor which directly interferes with responding during barbiturate withdrawal. While the data do not totally negate state dependent learning, some methodological issues about it are raised.
Asbestos in drinking water and cancer in the San Francisco bay area: 1969–1974 incidence☆

The relationship between ingested asbestos (through drinking water) and cancer of various body sites was examined. This study was a follow-up to another article that investigated this relationship. Age-adjusted, sex and race specific 1969–1974 cancer incidence ratios for 410 census tract groupings (‘super tracts’) of the San Francisco-Oakland Standard Metropolitan Statistical Area were compared with measured chrysotile asbestos counts in drinking waters of super tracts. The earlier article analyzed cancer data for the 3 yr period, 1969–1971. The present study used that data and an added set of cancer cases for 1972–1974. The water supplies serving the area have varying contact with naturally occurring serpentine. The t-test for multiple regression coefficients and the t-test for correlation coefficients showed significant (p < 0.01) relationships between chrysotile asbestos content of super tract drinking water and white male digestive tract, esophageal, stomach and pancreatic cancers. For white females, significant (p < 0.01) relationships on these tests were found for esophageal, stomach, digestive related organs, and pancreatic cancers. These associations appeared to be independent of income, education, asbestos occupation, marital status and mobility.
Structure-property relationships in polyamide/acrylonitrile-butadiene-styrene (ABS) blends

The structures and physical properties of four blends of poly(acrylonitrile-co-styrene-g-butadiene) (ABS) materials with polycaprolactam (PA6) have been characterized. The blends were separated into components by selective solvent extraction and were found to contain different structures: Blend A contained no PA6 grafts. Blend B contained PA6 grafted onto both soluble and insoluble ABS. Blend C contained PA6 grafted onto soluble poly(styrene-co-acrylonitrile) (p-SAN). In Blend D, PA6 was grafted onto both the insoluble ABS and the p-SAN phases. Transmission electron microscopy showed different morphologies in the blends. Blend A had a co-continuous, somewhat laminar structure, while Blend D consisted of an ABS phase dispersed in a PA6 continuum. Blends B and C had intermediate structures. All four blends, however, had very similar rheological and physical properties despite the variation in structure.
Folate cofactors regulate serine metabolism in fetal ovine hepatocytes.

The fetal liver is the primary site of fetal serine production. The regulation of this unique fetal hepatic serine production is unknown. We hypothesized that serine production would be responsive to folate cofactor supply or hormonal regulation. To test this hypothesis, we determined the effect of key folate cofactors and insulin and glucagon on serine and glycine metabolism in primary culture of fetal ovine hepatocytes. Hepatocytes were cultured in serum-free, low-folate media [5 nM 5-methyl-tetrahydrofolate (THF)] with or without 50 nM 5,10-methylene-THF (MTHF) or 5-formyl-THF (FTHF). Serine and glycine production (P) and utilization (U) were determined by stable isotope dilution with [1-13C]serine and [1-13C]glycine for 24 h. The effect of insulin (1 μM) or glucagon (1 μM) was determined in a similar manner. Under basal conditions, serine P (43.2 ± 5.1 μmol/mg DNA per 24 h) is greater than serine U (24.1 ± 3.1 μmol/mg DNA per 24 h), whereas glycine U (27.3 ± 3.0 μmol/mg DNA per 24 h) exceeds glycine P (16.7 ± 1.9 μmol/mg DNA per 24 h). MTHF results in a significant decrease in serine U (16.0 ± 2.7 μmol/mg DNA per 24 h;p = 0.02 versus low folate), with no change in serine P. FTHF reduces serine P (36.2 ± 4.9 μmol/mg DNA per 24 h;p = 0.01), but does not alter serine U. There were no effects on glycine metabolism with 50 nM MTHF or FTHF. Serine P and U were inversely correlated whereas glycine P and U were directly correlated with the media concentration of MTHF or FTHF. Glucagon treatment increased serine U by 260 ± 65%versus low folate (p = 0.0004) but did not change serine P. Insulin treatment led to parallel increases in both serine P and U. Both folate cofactor availability and hormone concentrations regulate serine metabolism in the fetal liver. We speculate that serine metabolism may be a marker of fetal hepatic folate cofactor supply.
An empirical approach to evaluating dependency locality in hierarchically structured software systems

In software development, especially component-based software development, dependency locality states that relevant software components should be at shorter distances than irrelevant components. This principle is used together with modularity and hierarchy to guide the design of large-scale complex software systems. In previous work, dependency locality and its correlation with design quality were studied by statically measuring the interactions between software components. This paper presents an empirical approach to evaluating the hierarchical structure of software systems through mining their revision history. Two metrics, spatial distance and temporal distance, are adapted to measure the dependencies between software components. The correlation of spatial distance and temporal distance between software components represents a factor that influences system design quality. More specially, a well designed system hierarchy should have a significant positive correlation while a non-significant positive correlation or a negative correlation would signify design flaws. In an application of this approach, we use Mantel test to study the dependency locality of six software systems from Apache projects.
Stereoselective syntheses of 3‐mercaptoproline derivatives protected for solid phase peptide synthesis

The incorporation of cis- and trans-3-mercaptoproline (3-MPc and 3-MPt) into analogs of biologically active peptides has been shown to be an effective means for reducing the conformational mobility of the peptide backbone. We report herein a novel stereoselective synthetic route to l-1 and l-2, derivatives of 3-MPt and 3-MPc suitably protected for solid phase peptide synthesis. The optically active starting material was the previously reported cis-3-hydroxyprolinol derivative l-3. Oxidation of the C1 alcohol to the carboxylic acid, formation of the methyl ester and deprotection of the C3 alcohol yielded l-6 in an overall yield of 68%. Reaction of the secondary alcohol with thiolacetic acid under Mitsunobu conditions gave the thiolacetate l-7 in 77% yield with clean inversion of configuration. Conversion of l-7 to l-1 was accomplished in a one-pot sequence consisting of three steps: hydrolysis of the thiolacetate, formation of the thioether and hydrolysis of the methyl ester. The overall yield of l-1 from l-3 was 38%. Synthesis of l-2 required an epimerization of l-6, which was accomplished using a standard Mitsunobu inversion to give the trans-3-hydroxyproline derivative l-8. Transformation of l-8 to l-2 followed that described for l-1, except that removal of the methyl ester from l-10 required acidolysis in refluxing 4N HCl. The overall yield of l-2 from l-3 was 18%. The availability of pure enantiomers of 3-MPt and 3-MPc protected for SPPS will greatly facilitate their use as conformational constraints for studying peptide-receptor interactions. © Munksgaard 1996.
The transition between small and long fatigue crack behavior and its relation to microstructure

The transition point from small to long crack behavior is experimentally studied in a single phase aluminum alloy. It is shown that scatter decreases until reaching a steady state value for long crack growth. This point is defined as the transition from micro-structurally small to long crack growth and is shown to correspond to the point when the growing crack front intersects approximately 15 grains. This transition point is experimentally validated from fatigue crack growth data both from single, corner micro-cracks and multi-site micro-cracks on a smooth surface.
The Distinction by Means of Tracers Between Active Transport and Diffusion

Summary. 1) It is shown that for a free ion diffusing through a membrane the ratio between the flux in one direction and the simultaneous flux in the opposite direction is independent of the structure of the membrane. This ratio , which can be evaluated through tracer experiments, is equal to the ratio between the electrochemical activities of the ion on the two sides of the membrane. 2) Deviations from the equation indicate that the ion does not diffuse in the free state only, but, in part at least, as a component of some other moving particle in the membrane. Complex formation for instance as a part of an active transport mechanism brings about deviations from the above equation. 3) The diffusion of iodide through the isolated surviving frog skin is studied by means of the radioactive I131. I- diffuses inwards faster than outwards under all conditions studied. Nevertheless, no active transport of I- need be postulated since the potential difference across the skin is somewhat higher than required to explain the difference in diffusion rate. 4) Both influx and outflux of I- show a negative correlation to the potential difference, so that high P. D. values are found only when the I- permeability is low.
Improvisation and the Logic of Exchange in Socially Embedded Transactions

We use a sensemaking lens to illuminate the micro-processes underlying socially embedded transactions, investigating how social ties affect the logic of exchange governing the transaction. In trans...
Issues in using multiple measures of quality of life

A review of the literature to identify the important aspects to measure in assessing the multidimensionality of quality of life shows some agreement on a few of the primary components affecting life quality, such as health, functional ability, and life satisfaction. However, some researchers have measured components that are seen less commonly, such as the patient’s feeling of usefulness to others. A review of such measurement approaches, encompassing both objective and subjective indicators, gives us a good idea of the multidimensional and diverse aspects of quality of life. A list of many of the components shaping a person’s quality of life is shown in Table 1. For ease of tabular display, these components are divided into physical, psychological, and social domains, although it is recognized that some of the components overlap more than one domain. It also should be pointed out that this list is only representative of the multidimensionality of quality of life, and is by no means exhaustive. Although quality of life is multidimensional in character, Aaronson’ cautions us that, in performing health-related quality of life studies, we should measure only those components of quality of life that we can reasonably expect may be affected by the illness, by the particular treatment regimen, or by the interventions of the health care providers. Aaronson identifies these components as generally falling into the following four major areas: functional status, symptoms related to the disease and to treatment, psychological functioning, and social functioning. Therefore, he believes that researchers are sometimes too ambitious in trying to measure numerous dimensions of a person’s life that clinicians or the treatment may not be able to impact directly (eg , self-esteem or family happiness).
Developmental Expression and Localization of Protein Phosphatase 2A in the Kidney † 1649

Although a number of growth and transcription factors are known to regulate kidney growth and development, the signal transduction molecules necessary to mediate developmental signals in the kidney remain largely unknown. Therefore activity, mRNA and protein expression of the signal transduction molecule protein phosphatase 2A (PP2A) were examined in kidneys from embryonic day 17 to 90 day old adults. Northern analysis of total kidney RNA or western analysis of kidney protein homogenates demonstrated developmental regulation of both the catalytic and major 55 kDa regulatory subunits of PP2A with the highest levels in the embryonic and newborn kidneys. Similarly PP2A enzyme activity was highest in the embryonic and newborn kidney. In situ hybridization with a digoxigenin labeled catalytic subunit cRNA probe mapped to mRNA expressing cells predominately in the nephrogenic cortex, particularly to developing glomeruli and not to developing tubular elements in the embryonic day 20 and newborn kidney. Similarly immunocytochemistry with a specific PP2A catalytic subunit polyclonal peptide antibody demonstrated localized catalytic subunit expression particularly to podocytes of developing glomeruli. Therefore the developmental regulation of PP2A during kidney development and its mapping predominately to developing glomeruli suggests a role for PP2A in the regulation of glomerular development.
Influence of cortisone on rate of absorption and formation of liver glycogen by alanine.

Summary1. The rates of absorption of D(-), L (+), and DL-alanine from the gastrointestinal tract of white rats were found to be 85, 110, and 112 mg/100 g of body weight/ hour, respectively. All 3 were approximately equal in their ability to form liver glycogen, maximum values were obtained 6 hours after administration. Cortisone administration had no effect upon the rate of alanine absorption. 2. When DL-alanine was fed to rats at the same time as 5 or 2.5 mg of cortisone was injected no increase in liver glycogen was obtained over the sum of the amounts formed when each of the substances was given separately. When DL-alanine and cortisone was administered so that the peak of glycogen formation for each compound was reached at the same time then there was a significant increase in glycogen formation over the sum of the independent actions of the 2 compounds.
TH‐SAM‐201B‐01: Technique Optimization in Digital Mammography

Historically optimization of screen‐film mammography has been constrained by the narrow latitude of film but that limitation is removed for new digital receptor‐based imaging systems which exhibit a high detection efficiency and wide dynamic range thus requiring new approaches for optimization of technical factors impacting image quality and dose. In this presentation we will review the impact of various technical parameters in digital mammography and methods employed for the assessment of optimal technique. Learning Objectives: 1. Understand the factors that impact image quality and dose in digital mammography 2. Learn methods to implement or verify technique factors for digital mammography systems.
Biological function, activity and dependency among elderly Sherpa in the Nepal Himalayas.

Abstract This paper considers a model contrasting the aging experience of Western and non-Western populations through consideration of the hypothesized interrelationships among four factors (biological change with age, dependency, family structure and the aging experience) in a non-Western setting. Western views of the contrast in the aging process in Western industrial and traditional pre-industrial societies include the notion that traditional societies manifest relatively slow rates of biological aging, and have extended family structures which accommodate the elderly resulting in few aging problems. On the basis of data deriving from a case study of Sherpas in Helambu, Nepal, the model appears to be an oversimplification and suggestions for revision are offered.
On the failure of the co-hopf property for subgroups of word-hyperbolic groups

We provide an example of a finitely generated subgroupH of a torsion-free word-hyperbolic groupG such thatH is one-ended, andH does not split over a cyclic group, andH is isomorphic to one of its proper subgroups.
Dynamic expression of the basic helix-loop-helix transcription factor neuroD in the rod and cone photoreceptor lineages in the retina of the embryonic and larval zebrafish.

NeuroD is a basic helix-loop-helix (bHLH) transcription factor critical for determining neuronal cell fate and regulating withdrawal from the cell cycle. We showed previously that, in goldfish, neuroD is expressed in the rod photoreceptor lineage, and we inferred that neuroD is also expressed in a subset of amacrine cells and nascent cone photoreceptors. Here we extended that study by examining the temporal and spatial expression pattern of neuroD in the embryonic and larval zebrafish and by identifying the cell types that express this gene. NeuroD expression in the developing zebrafish retina is dynamic, spanning early retinogenesis and the maturation of cone photoreceptors. In early retinogenesis neuroD expression expands from a small patch in the ventronasal retina, through the remaining retinal neuroepithelium. As retinogenesis progresses, neuroD expression becomes restricted to amacrine cells, immature cones, and cells of rod and cone lineages. This expression achieves an adult pattern by 96 hours postfertilization (hpf), whereupon the temporal pattern of neuroD expression in central retina is spatially recapitulated at the germinative margin. The cellular pattern of expression suggests that neuroD regulates aspects of rod and cone genesis, but through separate cellular lineages. Furthermore, neuroD is coexpressed with the cone-rodhomeobox transcription factor (Crx) in putative cone progenitors and nascent cone photoreceptors, suggesting that, in the zebrafish retina, as in other vertebrate retinas, similar genetic cascades regulate photoreceptor genesis and maturation. J. Comp. Neurol. 501:1–12, 2007. © 2007 Wiley-Liss, Inc. Indexing terms: neurogenesis; development; gene expression; photoreceptors
Active shooter in the emergency department: a scenario-based training approach for healthcare workers

Background: An active shooter in the emergency department (ED) presents a significant danger to employees, patients, and visitors. Very little education on this topic exists for healthcare workers. Using didactic and scenario-based training methods, the authors constructed a comprehensive training experience to better prepare healthcare workers for an active shooter. Methods: Thirty-two residents, nurses, and medical students participated in a disaster drill onboard a US military base. All were blinded to the scenarios.The study was approved by the institutional review board, and written consent was obtained from all participants. Each participant completed a 10-item pretest developed from the Department of Homeland Security’s IS:907 Active Shooter course. Participants were exposed to a single active shooter scenario followed by a didactic lecture on hostage recovery and crisis negotiation. Participants were then exposed to a scenario involving multiple shooters. Many of the participants were held hostage for several hours. The training concluded with a post-test and debrief. Paired Student’s t-test determined statistical significance between the pretest and post-test questionnaire scores. Results: Paired Student’s t-tests confirmed a statistically significant difference between the pretest and posttest scores for the subjects, as a whole (p < 0.002 [−0.177, −0.041]).There was no difference in scores for nurses (p = 1 [−1.779, 1.779]).The scores for resident physicians (p < 0.01 [−0.192, −0.032]) and medical students (p < 0.01 [−0.334, −0.044]) were found to be significant. Conclusions: Didactic lectures, combined with case-based scenarios, are an effective method to teach healthcare workers how to best manage an active shooter incident.
Project HEAL: A Community-Based, Learner-Centered Lay Health Worker Program † 636

One of the barriers to health care access is the socio-cultural gulf between underserved families and the health care community. We hypothesized that health workers with backgrounds similar to those of community members would be effective links between the health care community and those it serves. A children's health project using Community Health Workers (CHWs) was created to increase families' understanding of and involvement in basic child health issues. A community-based needs assessment was carried out; a community advisory board was formed for ongoing needs identification. A casemanaged “village” approach is used: CHWs enroll families from their own neighborhoods. In a learner-centered model, educational programs were devised by CHWs with technical direction from nurse and physician advisors. This presentation will outline the project and identify the successes and barriers encountered. Specific outcomes will be discussed.Six CHWs have been trained. By August 1997, 56 families (130 children) were participating. 264 home visits and 270 “other contacts” had been made. 155 community agency interactions took place as CHWs linked families with services. 12 health teaching topics have been identified through the community-based needs assessment; 6 have been implemented to date. 64 in-home assessments covering five health areas are completed. In order to understand the project's actual value to families, and to better characterize it, a qualitative ethnographic evaluation was performed. The following features of the program were revealed: The project is “learner centered” (based on knowledge from within the community, on the experiences of the CHWs and client families; learners become teachers, “training the trainer;” the program can adjust directly to the needs of the community). The project is community-based (the CHWs share life experiences with the population they serve; they have unique understanding of cultural systems and categories of the community; they build relationships with the community as a whole and families in particular based on an inherent sense of trust). The CHWs are used by client families for access to medical information, to review the health status of the family, to review acute conditions before using an Emergency Department or clinic, as facilitators when interacting with health or social institutions, as access to information regarding social services and support agencies, and for emotional support. In summary, the CHW is characterized as a “cultural translator” or “bridge” between the health care system and the community it serves.
β3 Integrin–EGF receptor cross-talk activates p190RhoGAP in mouse mammary gland epithelial cells

Active RhoA localizes to plasma membrane, where it stimulates formation of focal adhesions and stress fibers. RhoA activity is inhibited by p190RhoGAP following integrin-mediated cell attachment to allow sampling of new adhesive environments. p190RhoGAP is itself activated by Src-dependent tyrosine phosphorylation, which facilitates complex formation with p120RasGAP. This complex then translocates to the cell surface, where p190RhoGAP down-regulates RhoA. Here we demonstrate that the epidermal growth factor receptor (EGFR) cooperates with β3 integrin to regulate p190RhoGAP activity in mouse mammary gland epithelial cells. Adhesion to fibronectin stimulates tyrosine phosphorylation of the EGFR in the absence of receptor ligands. Use of a dominant inhibitory EGFR mutant demonstrates that fibronectin-activated EGFR recruits p120RasGAP to the cell periphery. Expression of an inactive β3 integrin subunit abolishes p190RhoGAP tyrosine phosphorylation, demonstrating a mechanistic link between β3 integrin-activated Src and EGFR regulation of the RhoA inhibitor. The β3 integrin/EGFR pathway also has a positive role in formation of filopodia. Together our data suggest that EGFR constitutes an important intrinsic migratory cue since fibronectin is a key component of the microenvironment in normal mammary gland development and breast cancer. Our data also suggest that EGFR expressed at high levels has a role in eliciting cell shape changes associated with epithelial-to-mesenchymal transition.
Grazing of Panicum amarum in a Louisiana barrier Island dune plant community: management implications for dune restoration projects

Abstract Panicum amarum (bitter panicum), an economically important dune grass used in dune building and stabilization projects throughout the southeastern United States, was planted in protected (exclosed) and unprotected (unexclosed) plots to assess the importance of vertebrate herbivory on P. amarum transplant survival on Timbalier Island, Louisiana. After one year, vegetative cover of P. amarum in exclosed plots increased to 33% with an accompanying stem density increase of 67%, whereas herbivory in the unexclosed plots resulted in 0% vegetative cover of P. amarum with no surviving stems. Total plant cover (P. amarum plus invading plant species) was also significantly greater within exclosures. Based on field observations of tracks and scat in the study area, nutria (Myocastor coypus) is believed to have been responsible for most, if not all, of the grazing. One of the invading plant species, Heterotheca subaxillaris, had significantly greater vegetation cover in exclosed plots, whereas the other invading species, Spartina patens, had similar percentage cover values within exclosed and unexclosed plots. Percentage N, crude fiber, moisture, and phenolic compounds varied significatly among the three plant species. The concentration of total phenols in Heterotheca was four to five times greater than those in Panicum and S. patens. We hypothesize that Panicum may be the heaviest grazed of these species because its leaf tissue is characterized by a combination of relatively high moisture content and low total phenols. Since the impact of herbivory varied among the three plant species, herbivores may significantly alter dune plant community structure by differentially consuming palatable plant species in the dune environment on some barrier islands. This may have serious management implications for Louisiana's barrier islands if plant species with the most desirable sand-accumulating and sediment-binding characteristics are also the most severely grazed by herbivores.
Crystallographic tilting during heteroepitaxial growth of rubidium iodide on mica

Heteroepitaxial deposits of RbI on mica were prepared by the evaporation of aqueous solutions under controlled conditions. Using four-circle x-ray diffractometer measurements to determine the orientation of the alkali halide lattice relative to the mica substrate, we find that the RbI [111] axis is often tilted relative to the substrate normal, along specific in-plane azimuths. Crystallographic tilting is a well-known phenomenon during heteroepitaxial growth of semiconductors and metals, but our results are somewhat unusual, since they involve the growth of an ionic crystal on mica. It is generally acknowledged that tilting is driven by epitaxial misfit accommodation, and for a net tilt to occur the interfacial system requires a symmetry-breaking component. In the vast majority of previous studies the broken symmetry is due to substrate miscut, but miscut is entirely absent in the case of cleaved mica substrates. In order to explain our results, we show that the tilting of RbI on mica is made possible by the inherent threefold symmetry of the [111] axis in fcc crystals, and we also show that the observed tilt angles are consistent with the lattice parameters of RbI and mica.
The Free Energies of Reactions of Chlorinated Methanes with Aqueous Monovalent Anions: Application of Ab Initio Electronic Structure Theory

The presence of different anionic species in natural waters can significantly alter the degradation rates of chlorinated methanes and other organic compounds. favorable reaction energetics is a necessary feature of these nucleophilic substitution reactions that can result in the degradation of the chlorinated methanes. In this study, ab initio electronic structure theory is used to evaluate the free energies of reaction of a series of monovalent anionic species (OH{sup {minus}}, SH{sup {minus}}, NO{sub 3}{sup {minus}}, HCO{sub 3}{sup {minus}}, HSO{sub 3}{sup {minus}}, HSO{sub 4}{sup {minus}}, H{sub 2}PO{sub 4}{sup {minus}}, and F{sup {minus}}) that can occur in natural waters with the chlorinated methanes, CCk{sub 4}, CCl{sub 3}H, CCl{sub 2}H{sub 2}, and CClH{sub 3}. The results of this investigation show that nucleophilic substitution reactions of OH{sup {minus}}, SH{sup {minus}}, HCO{sub 3}{sup {minus}}, and F{sup {minus}} are significantly exothermic for chlorine displacement, NO{sub 3}{sup {minus}} reactions are slightly exothermic to the thermoneutral, HSO{sub 3}{sup {minus}} reactions are slightly endothermic to thermoneutral and HSO{sub 4}{sup {minus}}, and H{sub 2}PO{sub 4}{sup {minus}} reactions are significantly endothermic. In the case of OH{sup {minus}}, SH{sup {minus}}, and F{sup {minus}} where there are limited experimental data, these results agree well with experiment. The results for HCO{sub 3}{sup {minus}} aremore » potentially important given the near ubiquitous occurrence of carbonate species in natural waters. The calculations reveal that the degree of chlorination, with the exception of substitution of OH{sup {minus}}, does not have a large effect on the Gibbs free energies of the substitution reactions. These results demonstrate that ab initio electronic structure methods can be used to calculate the reaction energetics of a potentially large number of organic compounds with other aqueous species in natural waters and can be used to help identify the potentially important environmental degradation reactions.« less
Conditional immortalization of neuronal cells from postmitotic cultures and adult CNS.

Abstract To ddetermine whether postmitotic neurons can be immortalized by oncogenic transduction, we used two approaches involving conditional expression of a temperature-sensitive SV40 large T antigen (Tts). Initially, Tts was introduced into E17 rat embryonal hippocampal cells that were then cultured at the non-permissive temperature to enrich for postmitotic pyramidal neurons, and subsequently cloned at the permissive temperature. One clonal line (HMR10-3) expressed neuron-specific proteins upon differentiation, was capable of generating action potentials, and formed synapses with primary rat neurons in co-culture. Replating of these postmitotic cells at the permissive temperature resulted in reversible loss of neurofilament expression. Conditionally immortalized cell lines were also generated from the brain of an adult mouse carrying an inducible Tts transgene. These lines proliferated in a T antigen-dependent manner and expressed neuron-specific proteins upon differentiation at the non-permissive temperature. These results suggest that postmitotic neurons can be induced to enter the cell cycle without losing their commitment to a neuronal lineage.
Parsing the Mechanisms that Increase Relational Intimacy: The Effects of Uncertainty Amount, Open Communication About Uncertainty, and the Reduction of Uncertainty

This study examined amount of uncertainty, openness of communication about uncertainty, and the uncertainty reduction process as three competing mechanisms that account for increased intimacy in romantic relationships. To test these competing mechanisms, we used multilevel modeling to analyze longitudinal data that were collected from individuals in romantic associations over a 6-week period. Results of separate analyses indicated that the amount of uncertainty was negatively associated with concurrent intimacy and the openness of communication about uncertainty, and decreases in uncertainty were positively associated with subsequent intimacy. When all three predictors were considered simultaneously, the decrease in uncertainty was the only significant predictor of intimacy. These findings highlight the importance of the uncertainty reduction process, rather than low amounts of uncertainty, for increased intimacy.
Skeletal Muscle Regulatory Proteins Enhance F-Actin In Vitro Motility

Using an in vitro motility assay, we have investigated the effects of rabbit skeletal muscle regulatory proteins, troponin and tropomyosin, on the gliding of F-actin filaments or F-actin filaments containing these regulatory proteins. We demonstrate that Ca2+ does not affect the motility of F-actin gliding on HMM, but does in the presence of skeletal muscle tropomyosin and troponin. We conclude that Ca2+ affects motility through troponin because, like F-actin, F-actin-Tm filaments show no Ca2+-dependence to their gliding speeds. Furthermore, there is a large enhancement of the gliding speed (about 75%) in the presence of skeletal muscle tropomyosin, troponin + saturating Ca2+ over that seen with F-actin filaments. This enhancement is not due to the action of tropomyosin alone as skeletal muscle tropomyosin without troponin enhances the speed little (about 5%) over that of F-actin. Thus troponin confers Ca2+ sensitivity to the motility and, additionally, potentiates motility greatly along with tropomyosin in the presence of saturating Ca2+. When [HMM] is varied, the decline in speed of F-actin seen at low HMM density is changed little by tropomyosin in the F-actin-Tm filaments. These data show that the skeletal regulatory proteins interact with F-actin to enhance the interaction with HMM particularly in the presence of troponin and saturating Ca2+ and enhance the gliding speed in the in vitro motility assay as they potentiate the ATPase activity in the isolated proteins. This enhancement of speed in the motility assay cannot be ascribed to tropomyosin alone.