cssi/SciSciGPT-SciSciNet huggingface dataset:
Swi/Snf chromatin remodeling/tumor suppressor complex establishes nucleosome occupancy at target promoters

Abstract Precise nucleosome-positioning patterns at promoters are thought to be crucial for faithful transcriptional regulation. However, the mechanisms by which these patterns are established, are dynamically maintained, and subsequently contribute to transcriptional control are poorly understood. The switch/sucrose non-fermentable chromatin remodeling complex, also known as the Brg1 associated factors complex, is a master developmental regulator and tumor suppressor capable of mobilizing nucleosomes in biochemical assays. However, its role in establishing the nucleosome landscape in vivo is unclear. Here we have inactivated Snf5 and Brg1, core subunits of the mammalian Swi/Snf complex, to evaluate their effects on chromatin structure and transcription levels genomewide. We find that inactivation of either subunit leads to disruptions of specific nucleosome patterning combined with a loss of overall nucleosome occupancy at a large number of promoters, regardless of their association with CpG islands. These rearrangements are accompanied by gene expression changes that promote cell proliferation. Collectively, these findings define a direct relationship between chromatin-remodeling complexes, chromatin structure, and transcriptional regulation.
The Influence of Certain Water Soluble Vitamins on Phosphorus (P32) in Bone Mineralization

Abstract Although water soluble vitamins have been reported to be related to perosis or slipped-tendon in chicks and poults they have not been reported to be related to phosphorus in bone mineralization. The abnormality of hock-joint, commonly known as perosis or slipped-tendon in chicks and poults, has been reported to be due to a deficiency of choline, Jukes (1940) and niacin, Jukes, Stokstad and Belt (1947). A folic acid concentrate was found by Hogan et al. (1940) to reduce the incidence of perosis in chicks. Patrick, Darrow and Morgan (1944) found that turkey poults developed perosis when fed a ration deficient in riboflavin. Recently, Scott (1951) reported that para-amino benzoic acid reduced the incidence of “swollen-hocks” in turkeys. The mode of action of the water soluble vitamins as related to perosis has not been determined. Radioactive phosphorus, P32, is being used in studies dealing with many body processes. Reported in this . . .
Catalyst particle sizes from Rutherford scattered intensities

SUMMARY We show that the number of atoms in a small supported catalyst cluster can be estimated from the strength of electron scattering into a high angle annular detector in the STEM. The technique is related to the Z contrast methods developed by Crewe, Wall, Langmore and Isaacson. It works best for high atomic number catalyst particles when supported on low atomic number supports, such as Pt on γ-aluminium oxide. The method is particularly useful for detecting and measuring particles in the sub-nanometre size range where bright field images are unreliable. Unlike the Z contrast methods, a high angle annular detector is used, which avoids intensity modulations arising from Bragg reflections. The signal is mostly high angle diffuse scattering, which is predominantly Rutherford scattering, and is proportional to the number of atoms probed by the beam, weighted by their individual scattering cross-sections. Scattering strengths of individual clusters are computed from digitized high angle annular detector images. Data for Pt on γ-aluminium oxide, when plotted as imaged area1/2 against intensity1/3, define a straight line. Such plots provide calibration of the intensity increment per atom without the need of external calibration, although assumptions about particle morphology must be made. Reliable results require high signal-to-noise and optimum sampling of the specimen. For an STEM probe size of 0.35 nm, Pt clusters containing as few as three atoms can be detected when supported on typical, 20 nm thick, γ-aluminium oxide supports.
Structural and functional abnormality of ectopic testes in rats

Some males of a mutant strain of King-Holtzman rats exhibit an anomalous heritable defect manifested as either unilateral or bilateral ectopic testes. In the adult, these testes contain seemingly immature Sertoli and Leydig cells, seminiferous tubules greatly reduced in diameter, and exhibit arrested spermatogenesis. Thus, the affected testis is essentially sterile. An inability to produce normal amounts of testosterone and androstenedione by these gonads is probably a reflection of changes that have been effected in their Leydig cells. Thus, this study suggests that abnormal function of the Leydig and Sertoli cells and seminiferous tubule failure in these mutant animals result from the physiologically cryptorchid condition.
Diagnostic imaging of suspected appendicitis in pregnant women: comparison of CT to ultrasonography

Purpose: To compare the sensitivity and specificity of CT versus ultrasonography for the diagnosis of appendicitis in a population of pregnant women. Materials and methods: Radiology records (1988–1999) were searched for results of examinations performed on pregnant patients with suspected appendicitis. Subjects included only women with known intrauterine pregnancies. Thirty-two pregnant women were identified who had been studied by CT, ultrasound, or both. Ten patients had undergone focused abdominal CT with colon contrast, while 29 had undergone abdominal or pelvic ultrasonography with attention to the appendix. Results were compared to surgical pathology or follow-up findings. Results: CT sensitivity was 100 %, specificity 100 %, positive predictive value (PPV) 100 %, negative predictive value (NPV) 100 % and accuracy was 100 %. Ultrasound sensitivity was 100 %, specificity 83 %, PPV 50 %, NPV 100 %, and accuracy 21 %. Conclusion: In this small cohort of gravid females with suspected appendicitis, the sensitivity of focused abdominal CT with colon contrast was equal to that in the nonpregnant patient. In contradistinction to this, abdominal ultrasonography was frequently indeterminate. We hypothesize that ultrasonography is less accurate due to body habitus and the variable location of the appendix during pregnancy.
Reversible translocation of EYFP-tagged STIM1 is coupled to calcium influx in insulin secreting β-cells

Abstract Calcium (Ca 2+ ) signaling regulates insulin secretion in pancreatic β-cells. STIM1 has been proposed to function as an endoplasmic reticulum (ER) Ca 2+ sensor regulating store-operated Ca 2+ entry (SOCE). Here we studied the translocation of EYFP-STIM1 in response to ER calcium depletion in mouse insulinoma MIN6 cells by fluorescent microscopy. While in resting cells EYFP-STIM1 is co-localized with an ER marker, in thapsigargin (Tg)-stimulated cells it occupied highly defined areas of the peri-PM space in punctae adjacent to, but not entirely coincident with the ER. Co-staining with fluorescent phalloidin revealed that EYFP-STIM1 punctae was located in actin-poor areas. Use of the SOCE blocker in MIN6 cells, 2-aminoethoxy diphenylborate (2-APB), prevented store depletion-dependent translocation of EYFP-STIM1 to the PM in a concentration-dependent (3.75–100 μM) and reversible manner. TIRF microscopy revealed that 2-APB treatment led to the reversible disappearance of peri-PM EYFP-STIM1 punctae, while the ER structure in this compartment remained grossly unaffected. We conclude from this data that in these cells EYFP-STIM1 is delivered to a peri-PM location from the ER upon store depletion and this trafficking is reversibly blocked by 2-APB.
Endolymphatic stromal myosis. Unique presentation and ultrastructural study

We describe a case of endolymphatic stromal myosis (ESM) in which the lesion presented uniquely as recurrent frond-like cervical polyps. The lesion behaved aggressively, spreading to the peritoneum. Ultrastructurally, this tumor closely resembled proliferative phase endometrial stroma, in accord with the theory that ESM is a low-grade stromal sarcoma. The ultrastructural correlations may aid in developing future therapy, including progestagen administration for these unusual tumors.
Symbiotic organisms increase the vulnerability of a hermit crab to predation

Abstract The association between the hermit crab Pagurus longicarpus Say and an ectosymbiotic colonial hydroid of the genus Hydractinia was studied to determine whether the presence of Hydractinia affects the resistance of Pagurus longicarpus to predation. Observations of tethered hermit crabs confirmed the importance of predation by the blue crab, Callinectes sapidus Rathbun, on the Pagurus longicarpus population in Nantucket Harbor, Massachusetts. In a predation experiment, caged hermit crabs in Littorina littorea (L.) shells with and without Hydractinia were exposed to single blue crabs. Shell damage indicated that blue crabs attacked hermit crabs in both shell types in roughly equal proportions: 65% of hermit crabs in shells with Hydractinia were attacked compared to 69% of hermit crabs in shells without Hydractinia . Only 20% of hermit crabs in shells with the hydroid survived attack, however, compared to 54% in shells without Hydractinia . Continuous observation of predation in aquaria showed that hermit crabs in shells with Hydractinia had significantly shorter survival times when attacked by a blue crab than hermit crabs in shells without the colonial hydroid. The crushing resistance of shells was measured with an Instron™ testing machine. A comparison of the regression equations of shell mass (g) vs. crushing resistance (N) between shell types showed that shells with Hydractinia had a lower slope than shells without Hydractinia , although because of a wide range in crushing resistance, this difference was not significant. Shells with Polydoran worm burrows, however, were significantly weaker than shells without burrows, and shells with Hydractinia were more likely to hold worms than shells without Hydractinia . The positive correlation between Hydractinia and shell-degrading worms explains the vulnerability of hermit crabs in shells with the colonial hydroid to predation by blue crabs. Other studies have shown that hermit crabs may benefit from having Hydractinia on their shells because the hydroid prevents large and potentially harmful ectosymbionts, such as Crepidula species, from colonizing. Thus, for Pagurus longicarpus the costs and benefits of the association with Hydractinia may change depending upon the presence of other organisms and this may shift the nature of the association with Hydractinia from mutualism to commensalism to parasitism
Characterizing Young Brown Dwarfs Using Low-Resolution Near-Infrared Spectra

We present near-infrared (1.0-2.4 � m) spectra confirming the youth and cool temperatures of six brown dwarfs and low-mass stars with circumstellar disks toward the Chamaeleon II and Ophiuchus star-forming regions. The spectrum of one of our objects indicates a spectral type ofL1, making it one of the latest spectral type young brown dwarfs identified todate.Comparingspectraof youngbrown dwarfs,fielddwarfs, andgiant stars, wedefinea1.49-1.56 � m H2Oindexcapableofdeterminingspectraltypeto � 1subtype,independentofgravity.Wehavealsodefinedanindex basedonthe1.14� msodiumfeaturethatissensitivetogravity,butonlyweaklydependentonspectraltype.Our1.14 � m Na index can be used to distinguish youngcluster members (� P5Myr) from youngfield dwarfs, both of whichmay have the triangular H-band continuum shape that persists for at least tens of Myr. Using TeA values determined from thespectraltypes ofourobjectsalongwithluminosities derivedfromnearandmid-infrared photometry,weplaceour objectsontheH-Rdiagramandoverlayevolutionarymodelstoestimatethemassesandagesofouryoungsources.Three of our sources haveinferredages (� '10-30 Myr) that are significantly older than the median stellar age of their parent clouds (1-3 Myr). For these three objects, we derive masses � 3 times greater than expected for 1-3 Myr old brown dwarfs with thebolometric luminosities of our sources.The largediscrepancies inthe inferred masses and agesdeter- mined using two separate, yet reasonable, methods emphasize the need for caution when deriving or exploiting brown dwarf mass and age estimates. Subject headingg infrared: stars — stars: formation — stars: low-mass, brown dwarfs
Recombinational histories of avian infectious bronchitis virus and turkey coronavirus

Phylogenetic analysis of complete genomes of the avian coronaviruses avian infectious bronchitis (AIBV) and turkey coronavirus (TCoV) supported the hypothesis that numerous recombination events have occurred between these viruses. Although the two groups of viruses differed markedly in the sequence of the spike protein, the gene (S) encoding this protein showed no evidence of positive selection or of an elevated mutation rate. Rather, the data suggested that recombination events have homogenized the portions of the genome other than the S gene between the two groups of viruses, while continuing to maintain the two distinct, anciently diverged versions of the S gene. The latter hypothesis was supported by a phylogeny of S proteins from representative coronaviruses, in which S proteins of AIBV and TCoV fell in the same clade.
An expression database for roots of the model legume Medicago truncatula under salt stress

Background Medicago truncatula is a model legume whose genome is currently being sequenced by an international consortium. Abiotic stresses such as salt stress limit plant growth and crop productivity, including those of legumes. We anticipate that studies on M. truncatula will shed light on other economically important legumes across the world. Here, we report the development of a database called MtED that contains gene expression profiles of the roots of M. truncatula based on time-course salt stress experiments using the Affymetrix Medicago GeneChip. Our hope is that MtED will provide information to assist in improving abiotic stress resistance in legumes.
Student Learning Style: A Segmentation Strategy for Higher Education

Student learning style has been modeled as a moderating variable in learning effectiveness and efficiency. This article proposes that student learning style can be related to easily identifiable de...
Politics in the Nation's Schools: The Battle for the Principalship:

Too many educators believe that good education is above politics. Not so, says this writer, who asserts that education is in every respect a battleground, one in which the principalship is key.
The determination of glyoxylic acid in biological systems

Abstract A method is described for the determination of glyoxylate (or the acid) which involves potentiometric titration of the NaOH produced as a result of the formation of the sulfite addition compound. Results are in good agreement with those from a less precise assay involving periodate oxidation. Using the sulfite method to determine the concentration of glyoxylate in stock solutions, a highly specific colorimetric procedure is described for the assay of more dilute solutions. Glyoxylate has an aM of 16,300. A diversity of compounds of biological interest, including carbonyl substances, does not interfere with the determination. Of the compounds tested, only glyoxal should interfere substantially at molar concentrations equivalent to glyoxylate.
The effectiveness of a complaint-based ethics enforcement system: Evidence from the accounting profession

Many professions, in order to enforce their ethics codes, rely on a complaint-based system, whereby persons who observe or discover ethics violations may file a complaint with an authoritative body. The authors assume that this type of system may encourage ethical behavior when practitioners believe that a punishment is likely to result from a failure to adhere to the rules. This perceived likelihood of punishment has three components: detection risk, reporting risk, and sanction risk. A survey of potential violation witnesses related to the accounting profession revealed that the profession's complaint-based enforcement system may not provide practitioners with the necessary disincentive to refrain from code violations.
Apps for social justice: motivating computer science learning with design and real-world problem solving

In this paper, we describe a twelve-week Apps for Social Justice course that we taught at an after-school program. Students read social justice literature, identified local community needs, and went through a design process to create fully functional mobile applications to address these needs. Using Nasir and Hand's concept of practice-linked identities, we argue that an integrative approach to introducing computer science -- where CS principles are used in pursuit of meaningful community goals -- provides multiple opportunities for students to participate in software development while connecting these skills and dispositions to their own experiences and to larger social issues. Unlike a concepts-first approach, which introduces computer science ideas using small, often decontextualized examples, a practiced-based approach that builds on student experiences may foster a more motivating and meaningful learning environment.
Calculation of bond dissociation energies of benzylic hydrogens: A comparative study

Abstract The bond dissociation energies for the benzylic hydrogen have been calculated for ten toluenes using MINDO/3 and MNDO procedures and for seven toluenes using ab initio methods at both the 4–31G and 6–31G levels. The results are examined in an attempt to ascertain the role of substituents in determining the bond-dissociation energies and the role of these in hydrogen abstraction reactions.
Detection and classification of underwater targets in background noise acoustic daylight

It has been reported that underwater target models, spheres and cylinders can be detected and classified in background acoustic noise. In this paper, the author presents his recent finding that underwater target is detectable in acoustic background noise in open waters. Using a resonance detection technique, G-Transform, the noise background of a number of AUTEC sample data files with mammal clicks were analyzed. From the noise backgrounds in these data files, a number of possible target signatures were observed. It suggests that real underwater targets may be detected and classified passively in background noise.
Anodes for lithium batteries: tin revisited

Abstract Pure tin, without the addition of conducting diluents or binders, has been evaluated as an anode in lithium cells. Capacities approaching 600 mAh/g are maintained for over 10 deep cycles, before falling off, indicating the inherent reversibility of the tin anode. These are comparable to those reported for Cu 6 Sn 5 and considerably higher than for deposited tin films. The tin grain size was determined and found to decrease with cycling from over 400 to below 100 nm over 10 cycles. The cell impedance increases significantly after 10 cycles, consistent with the observed loss of capacity on extended cycling.
Determination of Lead in Whole Blood by Filter Furnace Laser-Excited Atomic Fluorescence Spectrometry

Filter furnace laser-excited atomic fluorescence spectroscopy was used for the determination of lead in whole blood. The use of a Katskov filter has enabled the direct comparison between lead fluorescence signals obtained with blood standards and water standards. Only a simple dilution of the blood was required. This direct correlation has allowed the interpolation of the lead signal of blood samples using a lead water standard calibration curve. NIST certified blood samples were analyzed using the method with excellent results.
A comparison of observed and reported adult-infant interactions: Effects of perceived sex

Interactions of 16 adults (eight married couples whose youngest child was less than 2 1/2 years old) with a single actor infant, dressed as either a male or a female, were recorded and analyzed in four categories: direction of gaze, facial expression, physical contact with the infant, and toy used. After the interaction period, a 45-minute interview on child rearing was conducted with each member of the couple. Observed interactions were then compared with interview data. The results support previous studies which show that both male and female parents behave differently toward unfamiliar infants on the basis of perceived sex. However, parents, especially mothers, appeared unaware of their differential treatment of male and female infants. These results suggest subtle sex-typing of infants by adults.
A neutral naphthalene diimide [2]rotaxane.

A neutral donor–acceptor [2]rotaxane, which has been synthesized using click chemistry, has had its solid-state structure and superstructure elucidated by X-ray crystallography. Both dynamic 1H NMR spectroscopy and electrochemical investigations have been employed in an attempt to shed light on both geometrical reorganization and redox-switching processes that are occurring or can be induced within the [2]rotaxane.
Dynamic aperture study for the Duke FEL storage ring

Abstract The new lattice design of the Duke free electron laser (FEL) storage ring is described. The results of the 6-dimensional dynamic aperture study using single particle tracking codes are presented. The influence of 8-m FEL undulator on the dynamic aperture is studied.
Alpha-inhibin is a tumour-suppressor gene with gonadal specificity in mice.

The inhibins are α:β heterodimeric growth factors that are members of the transforming growth factor-β family. To understand the physiological roles of the inhibins in mammalian development and reproduction, a targeted deletion of the α-inhibin gene was generated by homologous recombination in mouse embryonic stem cells. Mice homozygous for the null allele (inhibin-deficient) initially develop normally but every mouse ultimately develops mixed or incompletely differentiated gonadal stromal tumours either unilaterally or bilaterally. Inhibin is thus a critical negative regulator of gonadal stromal cell proliferation and the first secreted protein identified to have tumour-suppressor activity.
Comprehensive noise performance of ultrathin oxide MOSFETs at low frequencies

Abstract An analytical model and analysis of the low frequency noise performance of ultrathin oxide MOSFETs are presented. The model includes the effects of gate tunneling leakage current, low frequency noise sources, and their cross correlation coefficient between the input and the output. The correlation coefficient is not negligible in the existence of direct tunneling current through the gate oxide, and has an impact on the overall noise performance at low frequencies. Based on the partition noise theory and BSIM4 gate leakage current model with the source–drain partition, the correlation coefficient is obtained from a physical and rigorous modeling of intrinsic noise sources. The calculated results are compared with correlation noise measurements and good agreement is observed. An analytical formulation of low frequency noise performance is newly derived using the frequency-dependent noise parameters P LF , R LF , and C LF . The noise performance parameters, such as minimum noise figure, optimum source resistance and reactance, are graphically presented to accurately predict the influence of the gate leakage current on the low frequency noise performance. From quantitative results simulated with typical device parameters, it is shown that the proposed model can be used for optimum design of ultrathin oxide MOS devices and circuits at low frequencies.
Malnutrition impairs postresection intestinal adaptation.

BACKGROUND Postresection intestinal adaptation is influenced by several factors, including luminal nutrients. Adaptation is impaired in the absence of luminal nutrients, even if the nutrition is maintained via total parenteral nutrition (TPN). Reduced enteral intake also inhibits adaptation if malnutrition is present, but the mechanism has not been completely defined. Our aim was to study the effect of reduced enteral nutrition on adaptation and enterocyte production and death after 50% proximal resection in rats. METHODS Eighteen Lewis rats underwent either transection (n =6) or 50% proximal resection (n =12). The resected animals either ate ad libitum (n = 6) or were offered 75% of ad libitum intake (n =6). Nutritional status and intestinal adaptation were determined 14 days after surgery. RESULTS Resected animals receiving 75% normal intake had decreased body weight (89% +/- 4% vs 112% +/- 2% and 112% +/- 1%, p < .05) and serum albumin (2.7 +/- 0.1 vs 3.2 +/- 0.0 g/dL and 3.0 +/- 0.1 g/dL, p < .05) compared with resection with normal intake and transection, respectively. Intestinal weight (0.32 +/- 03 vs 0.22 +/- 0.02 g/cm and 0.19 +/- 0.03 g/cm, p < .05) and diameter (10.5 +/- 0.5 vs 8.5 +/- 1.0 mm and 7.8 +/- 0.8 mm, p < .05) increased after resection alone compared with transection and malnourished resection groups. Gut weight and diameter and villus height were lower in malnourished resected animals than with transection. Crypt cell production rate was significantly lower in the reduced intake animals. Apoptosis was increased in both crypt and villus enterocytes in normally nourished but not malnourished resected animals. Villus apoptosis correlated with villus height. CONCLUSIONS Intestinal adaptation is impaired by a 25% reduction in enteral nutrients, confirming that both the route and quantity of nutrient intake are important in this process. Both enterocyte production and loss via apoptosis are decreased by reduced enteral intake and malnutrition after resection. The correlation between villus height and apoptosis suggests that the reduced apoptosis reflects the smaller enterocyte number in malnourished animals rather than an adaptive response to maintain intestinal structure.
Modification of the equivalence theorem due to loop corrections

We show that, because of mixing between longitudinal vector bosons and pseudo-Goldstone scalars and because of differences in external leg amputations, there are loop corrections to the equivalence theorem, which relates S-matrix elements of W/sup +- / and Z to those of their respective pseudo-Goldstone partners. We derive general compact expressions in the form of multiplicative factors to account for these effects. An explicit one-loop calculation is performed to demonstrate the consistency of our formulation. In the limit when the physical Higgs and/or the top quark become very massive, we obtain a result that there is no m/sub H//sup 2/, lnm/sub H//sup 2/, m/sub t//sup 2/, or lnm/sub t//sup 2/ dependence in these factors if on-shell or finite-momentum subtractions are used for renormalization. However, we have not been able to, nor do we think it likely to, arrive at this conclusion for higher-order loops.
Consumer valuation of new car attributes: An econometric analysis of the demand for domestic and Japanese/Western European imports

Although previous studies of new vehicle choice decisions have shown that consumers evaluate the attributes of domestic vehicles differently from those of imported vehicles, the assumption underlying these results is overly restrictive. In particular, there is no reason to assume, a priori, that the attributes of all imported vehicles have similar effects upon consumer choice behavior. A competing hypothesis, for example, is that consumers of U.S. and European automobiles have similar attribute valuations that are differentiated from those of Japanese consumers. In the present paper, a multinomial logit model of vehicle type choice is developed which more completely differentiates imports by country of origin. Using a 1985 national sample of new car buyers to estimate the model, willingness to pay measures were calculated and nested hypothesis tests on attribute valuation performed. The results supported the hypothesis that consumers value vehicle attributes differently depending upon its country of origin. Moreover, consumers do not have similar valuations on the attributes of all imports implying that an arbitrary distinction between domestic and imported vehicles may produce misleading results.
Evidence for the involvement of an energy-dependent process in gonadotropin-releasing hormone-stimulated luteinizing hormone release by rat anterior pituitary.

The involvement of an energy-dependent process in gonadotropin-releasing hormone-(GnRH) stimulated LH release in the anterior pituitary has been examined. Inhibitors of both glycolysis and oxidative phosphorylation inhibited stimulation by GnRH of LH release in a time- and dose-dependent manner. Iodoacetate and 2-deoxyglucose inhibited GnRH-stimulated LH release, and this inhibition was not overcome by the addition of pyruvate. Similarly carbonyl cyanide m-chlorophenylhydrazine, an uncoupler of oxidative phosphorylation, and sodium azide, an inhibitor of electron transport, decreased ATP levels, enhanced lactate accumulation, and inhibited GnRHstimulated LH release. These studies demonstrate that inhibition of glycolysis and oxidative phosphorylation with metabolic inhibitors lead to inhibition of GnRH-stimulated LH release. Based on these results, it is postulated that GnRH-stimulated LH release is dependent on an energy-dependent process.
Caring for street youth: a nursing challenge.

The Advocate is a forum for exploring our roles as advocates for the children and families we serve.
Biomechanical and Microstructural Properties of Fibulin-5 Null Mice

Fibulin-5 is an extracellular matrix (ECM) protein that interacts with integrins and plays a critical role in organizing elastic fibers. Gross observation and histological examination reveal that carotid arteries from fibulin-5 knockout (fib5-/-) mice have disrupted elastic lamellae and are more tortuous [1]. The properties of fibulin-5 null mice provide a unique platform for developing constituent based models for vascular mechanics. While numerous models for blood vessels exist, there is a need to relate measurable microstructural metrics of structurally-based constitutive relations. We performed mechanical tests on carotid arteries from wildtype (WT) and fib5-/-mice and imaged live vessels under multiple loading scenarios to quantify microstructure during deformation. We also fit experimental results to a constitutive relation based on Holzapfel’s model [2]. These results provide a basis for further model development.Copyright © 2009 by ASME
Sliding contact stresses in a two-dimensional layered elastic half-space

Abstract Knowledge of the contact stress state in layered media is important for quantitative understanding of the mechanical reliability of the media. The two-dimensional quasi-static stress analysis of a layer on an elastic half-space under combined normal and sliding cylindrical contact is studied. Results are presented for the stresses in both the layer and half-space and contrasted with the case of a homogeneous medium.
Selective modulation of task performance by octopamine in honey bee ( Apis mellifera ) division of labour

Octopamine treatment has previously been shown to increase honey bee foraging behaviour. We determined the effects of octopamine on other tasks to learn how octopamine affects division of labour in honey bee colonies. Octopamine treatment did not increase the rate of corpse removal from the hive, suggesting that elevated brain levels of octopamine do not act to increase the performance of all flight-related tasks. Octopamine treatment also did not increase attendance in the queen’s retinue, suggesting that elevated brain levels of octopamine do not act to increase responsiveness to all olfactory stimuli. Consistent with these findings, octopamine treatment enhanced the foraging response to brood pheromone but not the cell capping response, a component of brood care. These results demonstrate a relatively specific form of neuromodulation by octopamine in the regulation of division of labour in honey bee colonies.
Further efforts toward a molecular dynamics force field for simulations of peptides in 40% trifluoroethanol-water.

A set of force field parameters for trifluoroethanol (TFE) was shown in earlier work from this lab to give a good accounting of system density, translational diffusion coefficients, and the solvent fluorine–solute hydrogen NMR cross-relaxation parameter (∑HF) for acetate dissolved in 40% TFE–water. It has since been found that this parameter set performs poorly when used to predict ∑HF for interactions of TFE with the hydrogens of an octapeptide, [val5]angiotensin. In the present work, adjustment of nonbonded force field parameters for interactions of fluorine with hydrogen was explored with the goal of improving these predictions. Six sets of TFE parameters were examined. When used in conjunction with the TIP5PE water model, all gave values for system density, translational diffusion coefficients, and ∑HF for acetate–TFE interactions that were similar to experimental results. Increasing the Lennard–Jones σHF for fluorine–hydrogen interactions by 10% led to calculated solvent–solute cross-relaxation param...
Fine particulate matter and cardiovascular disease

Abstract The 1996 EPA Air Quality Criteria for Particulate Matter relied in large part upon epidemiologic studies of the short-term (acute) effects of inhalable particulate matter (PM) exposures on all-cause mortality and hospitalizations with very limited experimental evidence from toxicology or clinical studies. Recent research has identified several plausible biological mechanisms for both the initial pulmonary injury and the consequent systemic effects. Current epidemiologic research interests include the component(s) of PM which are responsible for the initial pulmonary injury, the effects of co-pollutants such as ozone, and the pathophysiological mechanisms for PM-induced acute health effects.
Normal Corpus Callosum in Emx1 Mutant Mice with C57BL/6 Background

The Emx1 gene is a mouse homologue of a Drosophila head gap gene, empty spiracles. Corpus callosum defects have been reported for mutant mice lacking the Emx1 gene, indicating a possible involvement of the Emx1 gene in the regulation of axon guidance during development. However, it has recently come to light that genetic background could influence the outcome of the corpus callosum defects in mutant mice generated by ES cell technology. To investigate whether the corpus callosum defects resulted directly from Emx1 gene inactivation, we backcrossed the Emx1 mutant mice into the C57BL/6 background and found that the Emx1 homozygous mutant mice with the C57BL/6 background showed a normal corpus callosum score even though the cross-sectional area was 8% less than that of their wild-type littermates, indicating that genetic background could change the pattern of corpus callosum defects in Emx1 mutant mice. Furthermore, the indusium griseum and taenia tecta were always present and the cerebral cortical layers were well differentiated in Emx1 mutant mice. These results suggest that inactivation of the Emx1 gene does not contribute directly to the defects of corpus callosum and other brain structures associated with Emx1 mutant mice derived from a 129/Sv background.
The Jaombilo of Tamatave (Madagascar), 1992–2004: Reflections on Youth and Globalization

In Madagascar, the cultural and economic changes that have accompanied economic liberalization have also seen the emergence of the jaombilo, a young man supported by the money that a woman earns from sex work. In this article, I explore the structural forces that have contributed to the emergence of the jaombilo as well as the more subjective process through which young men become jaombilo. I argue that the category of the jaombilo emerged because of the particular ways in which global economic change articulates with local conceptions of youth, gender and economy. I further suggest that the case of the jaombilo challenges the assumption that youth is a normative phase on the way to adulthood. Instead, I argue that for young men in Madagascar, youth is a phase that they cannot escape. Much as savages were figured as "children" in the 19th century evolutionary discourse, many contemporary Malagasy young men have become perpetual youth, and perpetually poor, thereby challenging normative models of human development that emerged in the context of modernity.
Anatomy of the baculum-corpus cavernosum interface in the norway rat (Rattus norvegicus), and implications for force transfer during copulation.

The baculum is a nonappendicular bone found in the glans tissue of members of five orders of mammals. Its function during copulation is unknown. Anatomical examination of the baculum and corpus cavernosum in the Norway rat (Rattus norvegicus) shows that the two structures are connected by a layer of fibrocartilage, and that the distal tip of the corpus cavernosum swells during erection to surround the proximal end of the baculum. Microradiographs of bacula from sexually experienced males show that regions of the bone may be remodeling; these data suggest that the baculum is load-bearing. On the basis of this anatomy, I propose that the baculum increases the overall flexural stiffness of the penis during copulation by transferring bending and compressive forces from the distal end of the glans to the tensile wall of the corpus cavernosum. Forces on the distal end of the penis during copulation press the baculum against the corpus cavernosum, reducing its internal volume and increasing intracavernosal pressure and corpus cavernosum wall strains. Because the wall of the erect corpus cavernosum is reinforced with inextensible collagen fibers, an increase in wall strain will also increase wall tissue stiffness, and thereby increase the flexural stiffness of the corpus cavernosum.
Cerebral lactic acidosis correlates with neurological impairment in MELAS

Objective: To evaluate the role of chronic cerebral lactic acidosis in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS). Methods: The authors studied 91 individuals from 34 families with MELAS and the A3243G point mutation and 15 individuals from two families with myoclonus epilepsy and ragged red fibers (MERRF) and the A8344G mutation. Subjects were divided into four groups. Paternal relatives were studied as controls (Group 1). The maternally related subjects were divided clinically into three groups: asymptomatic (no clinical evidence of neurologic disease) (Group 2), oligosymptomatic (neurologic symptoms but without the full clinical picture of MELAS or MERRF) (Group 3), and symptomatic (fulfilling MELAS or MERRF criteria) (Group 4). The authors performed a standardized neurologic examination, neuropsychological testing, MRS, and leukocyte DNA analysis in all subjects. Results: The symptomatic and oligosymptomatic MELAS subjects had significantly higher ventricular lactate than the other groups. There was a significant correlation between degree of neuropsychological and neurologic impairment and cerebral lactic acidosis as estimated by ventricular MRS lactate levels. Conclusions: High levels of ventricular lactate, the brain spectroscopic signature of MELAS, are associated with more severe neurologic impairment.
Introduction to “Environmental Justice”

Justice issues have been prominent in the environmental debate since its beginning in the second half of the twentieth century. This is not surprising, because environmental crises highlight our conceptions of justice, challenging us to consider their adequacy as well as their implications. Does current justice theory accurately describe the issues raised by environmental threats, especially about the justice for future generations? What are the implications of perceptions of justice or injustice for responses to environmental problems, up to and including social protest? For the most part, environmental social sciences have not been at the forefront of these debates, despite some very important contributions. The goal of the present issue is, therefore, to bring together researchers in the field of environmental psychology and justice research and to provide a forum for current research in the field of environmental justice. This introduction gives a short overview of past, present, and emerging findings and questions.
Determination of higher-order terms in asymptotic elastoplastic crack tip solutions

A METHODOLOGY for the calculation of higher-order terms in asymptotic elastoplastic crack tip solutions is developed. The J2-deformation plasticity theory with power law hardening is used to describe the constitutive behavior of the continuum. A two-term expansion of the solution in the near crack tip region is developed. Plane stress and plane strain solutions for a crack in a homogeneous material as well as for a crack lying along the interface between a rigid substrate and an elastoplastic medium are obtained. For the case of a plane strain crack in a homogeneous material, it is shown that, when the hardening capacity of the material is small, the effects of elasticity enter the asymptotic solution to third order or higher, when there is substantial hardening, however, elastic effects enter the solution to second order and the magnitude of the second term in the expansion of the solution is controlled by the J-integral. THE CHARACTERIZATION of the stress and deformation fields in the region near the tip of a crack is essential for the development of sound fracture criteria. HUTCHINSON (1968) and RICE and ROSENGREN (1968) developed the elastoplastic asymptotic solution for the near-tip stresses in a homogeneous material (known as the HRR solution) and showed that the magnitude of the dominant term in the expansion of the solution is determined by the J-integral (RICE, 1968). If the region of dominance of the leading-order term in the expansion of the solution is sufficiently larger than the region over which the fracture micro-mechanisms take place, then the J-integral can be used as the fracture parameter. If the region of J-dominance, however, is smaller than the fracture process zone, then two or more parameters may enter the fracture criterion. LI and WANG 0986) suggested the use of a parameter k2, which is the magnitude of the second term in the near-tip stress plastic solution, as the second parameter to be used together with the J-integral in the fracture criterion. BETEGrN and HANCOCK (1991) used a modified boundary layer formulation of the small-scale yielding problem, in which the boundary conditions are defined in terms of the mode I stress intensity factor Kt and the constant stress term T that enters the near-tip expansion of the elastic solution (LARSSON and CARLSSON, 1973; RICE, 1974), and
Integrated Lecture and Laboratory Modules for Contaminant Transport Studies in Undergraduate Geotechnical Engineering

The engineering concepts necessary for fully describing contaminant transport processes in soil and groundwater have been largely neglected by traditional civil engineering curricula in the United States. New lecture and laboratory modules have been developed and integrated into the undergraduate soil mechanics course for civil engineering students at the Colorado School of Mines. The lecture module includes theoretical development of the advection-dispersion equation and a set of practical example problems designed to clarify the relative importance of advection, dispersion, and molecular diffusion in realistic contaminant transport scenarios. The laboratory experiment is developed using relatively inexpensive soil permeability testing equipment common to most academic and industrial geotechnical engineering laboratories. Unlike conventional chemical transport testing, which requires relatively complicated, time con- suming, and expensive analytical instrumentation, the new laboratory exercise relies on the use of simple colored dye for simulating the movement of a contaminant through a one-dimensional soil column. The key soil parameters governing the transport of the dye, including the diffusion coefficient, hydraulic conductivity, dispersion coefficient, and retardation coefficient, are quantified by observing the location and color intensity of the dye as it moves through the column. Emphasis is placed on maximizing the simplicity and visual impact of the experimental exercise. The effectiveness of the lecture and laboratory modules is assessed through a student survey.
Assessment of cytotoxicity of (N-isopropyl acrylamide) and Poly(N-isopropyl acrylamide)-coated surfaces

Poly(N-isopropyl acrylamide) (pNIPAM) is one of the most popular stimulus-responsive polymers for research. It is especially of great interest in the field of tissue engineering. While it is known that the NIPAM monomer is toxic, there is little conclusive research on the cytotoxicity of the polymer. In this work, the relative biocompatibility of the NIPAM monomer, pNIPAM, and pNIPAM-coated substrates prepared using different polymerization (free radical and plasma polymerization) and deposition (spin coating and plasma polymerization) techniques was evaluated using appropriate cytotoxicity tests (MTS, Live/Dead, plating efficiency). Four different mammalian cell types (endothelial, epithelial, smooth muscle, and fibroblasts) were used for the cytotoxicity testing. The pNIPAM-coated surfaces were evaluated for their thermoresponse and surface chemistry using X-ray photoelectron spectroscopy and goniometry. We found that while cell viability on pNIPAM surfaces decreases when compared to controls, the viability also seems to be deposition type dependent, with sol–gel based pNIPAM surfaces being the least biocompatible. Long term experiments proved that all pNIPAM-coated surfaces were not cytotoxic to the four cell types evaluated in a direct contact test. Plating efficiency experiments did not show cytotoxicity. Cellular sensitivity to pNIPAM and to the NIPAM monomer varied depending on cell type. Endothelial cells consistently showed decreased viability after 48 hours of exposure to pNIPAM extracts and were more sensitive than the other cell lines to impurities in the polymer.
Exposure-response analysis of pregabalin add-on treatment of patients with refractory partial seizures

Objective Our objectives were to describe the exposure-response relationship of pregabalin add-on treatment for refractory partial seizures after multiple dosing in patients and to identify the factors that influence this relationship. Methods A mixed-effects model was used to characterize the relationship between monthly seizure frequency over a 3-month period and pregabalin daily dose (0, 50, 150, 300, and 600 mg) as add-on treatment in 3 double-blind, parallel-group studies in patients with refractory partial seizures (N = 1042). Seizure frequency was modeled as a Poisson process expressed as a function of baseline seizures, drug treatment, placebo effect, and subject-specific random effects. The model included a parameter that partitioned the population into subpopulations with respect to response. Results Seventy-five percent of patients showed an asymptotic decrease in seizure frequency with increasing doses of pregabalin, whereas 25% did not demonstrate a significant decrease in seizure frequency from baseline. In patients who demonstrated a dose-related decrease in seizure frequency from baseline, the maximal percentage of seizure reduction from baseline was 100% for women and 80% for men, with a 186-mg daily dose decreasing seizures on average to 50% of maximum. Age, race, and menopausal status did not significantly affect seizure frequency. Conclusion Pregabalin add-on treatment demonstrates a dose-response relationship in 3 out of 4 patients with refractory partial seizures. A dose of 186 mg pregabalin daily is expected to decrease the seizure rate by 50% of maximum from baseline. Age, race, and menopausal status of women did not affect the dose-response relationship.
In vitro three-dimensional tumor microenvironment models for anticancer drug discovery

Anticancer drug discovery has long been hampered by the poor predictivity of the preclinical models. There is a growing realization that the tumor microenvironment is a critical determinant of the response of cancer cells to therapeutic agents. The past 5 years have seen a great deal of progress in our understanding of how the three-dimensional microenvironment modulates the signaling behavior of tumor cells. The present review discusses how three-dimensional in vitro cell culture models can benefit cancer drug discovery through an accurate modeling of the tumor microenvironment, leading to more physiologically relevant experimental outcomes.