cssi/SciSciGPT-SciSciNet huggingface dataset:
Urea-Induced Conformational Changes in dsDNA Probed by Solid-State Nanopores

Urea is an uncharged, polar molecule used ubiquitously as a structural denaturant for proteins, a hydrogen bond destabilizer in nucleic acids, and to increase the resolution of similar DNA fragments in electrophoretic processes. Despite its widespread use, the precise effects of varying urea concentrations on dsDNA structure are unknown. Solid-state nanopores in the range 2.7 - 4.5 nm have recently been shown to accurately gauge the effective diameter of dsDNA in aqueous solutions[1]. This DNA sizing method involves measurement of the reduction of a high ionic-strength electrolyte current as DNA transverses the pore. In this study, we systematically vary urea concentrations in the electrolyte solution (0 - 8.6M) and measure its effects on the effective DNA cross-section. Using an 800 bp dsDNA fragment, our studies reveal that the mean DNA effective diameter increases by as much as 0.6 nm. Further, the effective DNA diameter as a function of urea concentration follows a sigmoidal trend, indicative of cooperative binding. This interpretation is also supported by the translocation dynamics of the DNA as a function of urea concentration. We will present our experimental results along with a simple model to explain these observations.[1]Wanunu, M., Sutin, J., McNally, B., Chow, A. & Meller, A. (2008) DNA Translocation Governed by Interactions with Solid State Nanopores. Biophys J 95, in press.
Asthma caused by occupational exposure to a furan-based binder system

A 50-yr-old mold maker developed severe asthma a few weeks after commencing work with a furan binder. Asthma recurred within hours of subsequent exposure and was confirmed by measurements every 2 hr of peak flow rate. The molds were prepared by mixing sand with a resin (containing furfuryl alcohol, paraformaldehyde, and xylene) and a catalyst (containing sulfuric acid, phosphoric acid, and butyl alcohol). Occupation-type exposure in the laboratory to the resin mixed with catalyst, and to pure furfuryl alcohol mixed with sulfuric acid or butyl alcohol, provoked late asthmatic responses and heightened nonallergic bronchial responsiveness to inhaled histamine. No changes were produced by the same exposures in an asthmatic volunteer with a similar degree of histamine bronchial responsiveness, or in the worker after exposure to resin alone and catalyst alone. Avoidance of exposure was followed by clearing of symptoms and return of histamine bronchial responsiveness towards normal. The findings identify the occurrence of specific bronchial responsiveness to volatile reaction product(s) of furfuryl alcohol following reaction with sulfuric acid or with butyl alcohol. The incidence of this problem needs investigation, especially since furan-based binder systems are replacing traditional methods.
Optimization of layered manufacturing process for reducing form errors with minimal support structures

Abstract Layered manufacturing (LM) has evolved from the rapid prototyping (RP) method to a mainstream process for manufacturing high precision parts for aerospace, automotive and medical industries. LM inherits from RP several advantages including the ability to produce complex shapes, low cost and elimination of special tooling, as well as disadvantages of poor surface finish, poor dimensional accuracy, high build time and high waste. As LM is increasingly being accepted as a traditional manufacturing process, it has to consistently manufacture parts with minimal errors while keeping the material utilization to a minimum. This paper analyzes the effect of part orientation on two types of form errors, namely, cylindricity and flatness errors. An algorithm to calculate the optimal orientation for minimizing flatness and cylindricity errors is developed and tested with the help of two test cases. However, an optimal orientation for minimum form errors may result in a greater utilization of support structures which increases the material consumption in LM processes and therefore should be avoided. A voxel-based approach for calculating support structures has been developed in this paper which is then applied to minimize the volume of support structures while minimizing the cylindricity and flatness errors of the part features. This combined optimization is applied on two test parts and the results are provided.
Knocking Down Liver CCAAT/Enhancer-Binding Protein α by Adenovirus-Transduced Silent Interfering Ribonucleic Acid Improves Hepatic Gluconeogenesis and Lipid Homeostasis in db/db Mice

CCAAT/enhancer-binding protein-alpha (C/EBPalpha) is a member of the basic leucine zipper transcription factor family and regulates expression of several enzymes in the liver that control glucose and lipid metabolism. Using adenovirus-transduced silent interfering (si)RNA against C/EBPalpha, endogenous liver C/EBPalpha protein was knocked down by 70-80% in 8-wk-old wild-type (WT) and db/db mice. In WT mice, fasting blood glucose concentrations were reduced approximately 24% without changes in plasma free fatty acid and triglycerides, when compared with LacZ adenovirus-treated control mice. Ad-C/EBPalpha siRNA treatment nearly normalized fasting glucose and significantly reduced plasma insulin and free fatty acid content, even though there was no elevation of C/EBPalpha protein in the livers of db/db mice. In parallel with the changes in glucose levels, hepatic glucose production was significantly reduced in C/EBPalpha siRNA-treated WT and db/db mice. mRNA levels of phyosphoenolpyruvate carboxykinase, glucose-6-phosphatase, and liver glycogen synthase were decreased in the C/EBPalpha siRNA-treated WT and db/db mice. Interestingly, the magnitude of reduction in these enzymes was more profound in db/db mice. C/EBPalpha siRNA also decreased mRNA levels of proliferator activator protein-gamma coactivator-1alpha in both the WT and db/db mice but reduced cAMP response element-binding protein only in WT and did not alter hepatic nuclear factor-4alpha and CBP/p300 expression. Expression of genes involved in lipogenesis, such as fatty acid synthase, acetyl-CoA carboxylase, and sterol regulatory element-binding protein-1c was robustly suppressed in the C/EBPalpha siRNA-treated db/db mice. Taken together, these results indicate that C/EBPalpha plays an important role in maintaining glucose and lipid homeostasis in the liver.
RESPIRATION OF ACORNS AS RELATED TO TEMPERATURE AND AFTER-RIPENING.

It is well known that while acorns of the white oak group will germinate as soon as they fall from the tree, acorns of the red oak group will not germinate until they have undergone a period of after-ripening. Although the red oak acorns are morphologically mature they must undergo certain physiological changes before they will germinate even under the most favorable conditions. The nature of the physiological changes occurring during the after-ripening of acorns is not fully understood. Korstian (6) found that after-ripening is affected by temperature. Storage at an average night temperature of 50? F. (10.0? C.) and day temperature of 65? F. (18.3? C.) resulted in the most satisfactory after-ripening as judged by promptness of germination and the percentage finally germinating. It appears that certain chemical and physiological changes occur in red oak acorns during over-wintering and the accompanying after-ripening which do not occur in acorns of the white oak group. It was believed that concurrent measurements of the 02 consumption and C02 production of acorns of the white and red oak groups might supply some information concerning differences in the physiology of the two groups. It also seemed possible that periodic measurements of the rate of respiration and the respiratory quotient of red oak acorns stored at various temperatures would indicate the effects of storage temperature on the rate of after-ripening and the accompanying physiological changes. Acorns of northern red oak [Quercus borealis var. maxima (Marsh.) Ashe] and white oak (Quercus alba L.) were chosen for these studies because they are widely distributed and representative species of the two principal groups of oaks. Methods
Drought and Deforestation: Has Land Cover Change Influenced Recent Precipitation Extremes in the Amazon?

AbstractExpansion of agricultural lands and inherent variability of climate can influence the water cycle in the Amazon basin, impacting numerous ecosystem services. However, these two influences do not work independently of each other. With two once-in-a-century-level droughts occurring in the Amazon in the past decade, it is vital to understand the feedbacks that contribute to altering the water cycle. The biogeophysical impacts of land cover change within the Amazon basin were examined under drought and pluvial conditions to investigate how land cover and drought jointly may have enhanced or diminished recent precipitation extremes by altering patterns and intensity. Using the Weather Research and Forecasting (WRF) Model coupled to the Noah land surface model, a series of April–September simulations representing drought, normal, and pluvial years were completed to assess how land cover change impacts precipitation and how these impacts change under varied rainfall regimes. Evaporative sources of water ...
A novel role for calpains in the endothelial dysfunction of hyperglycemia

Recent studies have reported that the activity of the calcium-dependent protease calpain is increased in acute inflammatory processes of the cardiovascular system. Because diabetes is associated with vascular inflammation, we hypothesized that increased calpain activity in response to hyperglycemia may play a role in diabetic cardiovascular disease. The effects of calpain inhibition on leukocyte-endothelium interactions induced by hyperglycemia were examined by intravital microscopy. Intraperitoneal administration of the selective calpain inhibitor benzyloxycarbonyl-leucyl-leucinal (5 micromol/L) prevented the up-regulation of leukocyte-endothelium interactions in response to 25 mmol/L D-glucose via a nitric oxide-dependent mechanism. Furthermore, treatment of rats with D-glucose significantly decreased basal endothelial NO release in mesenteric post-capillary venules, a phenomenon prevented by inhibition of calpain activity. Immunoprecipitation studies revealed that glucose induces loss of NO via a calpain-dependent decrease in the association of hsp90 with endothelial nitric oxide synthase. In addition, inhibition of calpain activity decreased endothelial cell surface expression of the pro-inflammatory adhesion molecules ICAM-1 and VCAM-1 during hyperglycemia. These data demonstrate that calpains contribute to important inflammatory events during hyperglycemia and that pharmacological inhibition of calpain activity attenuates leukocyte-endothelium interactions and preserves eNOS function.
Response of linear high polymers to hydrostatic pressure

The bulk compressibility of linear high polymers has been found to be a function of temperature, pressure, and time. Linear high polymer melts are highly compressible. Addition of pressure causes a structural change in some linear high polymer melts. In the case of amorphous polymers, such as polystyrene, a glassy state response to hydrostatic compression was found at a temperature well above the second-order transition temperature. In the case of polycrystalline materials, such as polyethylene, pressureinduced crystallization can take place at temperatures above the melting point. In either case, the process requires a higher pressure as temperature is increased. This process is found to be time dependent. There are indications that such structural changes could not take place above a specific temperature limit for any given material, regardless of the amount of pressure. By subjecting a melt of polyethylene to pressure and then cooling, a material that is more dense, more rigid, and more crystalline than the original injection-molded specimen can be obtained. The effects of the bulk compressibility on the fabrication condition of plastics as well as product properties are discussed.
Habit Formation and the Gains from Price Stability

A counter-intuitive result from consumer theory is that consumers facing stable prices will benefit from a mean-preserving spread of those prices. This article explores a new explanation for why the common intuition that price volatility is undesirable may be correct: the presence of habit formation in consumption. If prices are fluctuating, and preferences depend on past consumption, in every period the most favored goods can also be the most expensive ones, with negative consequences for both welfare and nutrition. (JEL codes: E2, O1, D9, I15) Copyright The Author 2012. Published by Oxford University Press on behalf of Ifo Institute, Munich. All rights reserved. For permissions, please email: journals.permissions@oup.com, Oxford University Press.
An evolutionary model of social change in the Middle Ohio Valley: Was social complexity impossible during the late woodland but mandatory during the late prehistoric?

Abstract We present an evolutionary model of social change in the Middle Ohio Valley during the Fort Ancient period (AD 1000–1650), primarily relying on an application of Winterhalder’s (1986) and Kelly’s (1995) evolutionary ecology model of cultural responses to environmental variability. We predict changes in social organization, political complexity, and patterns of stylistic similarity. As the environmental background for our model we employ recently published moisture data. By iteratively applying the synchronic Winterhalder–Kelly model we are able to predict a sequence of general trends that agree with much current interpretation of Fort Ancient development. Specifically, the model leads us to expect increasing village size, the development of regional traditions, and the development of leadership roles and a region-wide style Horizon around AD 1400. However, our model provides the ability to make testable predictions that deviate from the accepted cultural history and predicts that the Middle Ohio Valley and the groups referred to as Fort Ancient were far from homogenous.
A histochemical examination of the metabolic profiles of rat ventral tegmental area and substantia nigra arterioles

To determine the metabolic profiles of arterioles of the rat ventral tegmental area and zona compacta and zona reticulata of the substantia nigra (SN), the distribution of selected enzymes, or by-products, of key metabolic pathways were examined histologically. Arterioles of all three regions expressed the enzymes required for aerobic and anaerobic metabolism. However, the relative abundance of the enzymes and byproducts suggests a lower metabolic capacity for the SN than the ventral tegmentum, while lipid catabolism in both regions appears non-operative. Moreover, the larger ventral tegmental arterioles possess a greater potential for nucleic acid and protein synthesis. Together, these results suggest the larger ventral tegmental arterioles possess a greater capacity for proliferation and repair.
Criterion for heat transfer modeling of unsteady droplet combustion

Abstract A criterion is developed which determines the unsteady temperature modeling of a single spherical fuel droplet burning in a nonconvective environment: the lumped (temporally varying but spatially uniform droplet temperature) -and distributed (temporally and spatially varying droplet temperature) -parameter models. It is concluded that for most industrial cases the distributed-parameter approach should be employed since the lumped-parameter one can not yield sufficiently accurate prediction.
A Novel, Wafer-Level Method to Fabricate Zero-Mode Waveguides for Single Molecule Detection

Zero-mode waveguides (ZMWs) are hollow, metal apertures that are substantially smaller than the wavelength of light typically used in fluorescence spectroscopy. Consequently, ZMWs restrict excitation illumination to sub-diffraction limited (zeptoliter-scale) volumes. Such small confinement volumes enable single molecule detection at micromolar concentrations of fluorescently-labeled target molecules, and hence offer a powerful tool for single molecule observations under near-physiological conditions. The primary limitation to the widespread use of ZMWs in modern biological laboratories is that well-defined nanoapertures currently require expensive fabrication methods to produce. Here, we present a novel method to create ZMWs that employs conventional, low-cost, wafer-level fabrication techniques. We first use conventional photolithography to pattern larger, microapertures (800-1000 nm diameter) into a gold film covering a glass microscope slide. The microapertures are then subjected to metal electrodeposition, where the metal-of-interest is plated onto all accessible metal surfaces. Consequently, the diameter of the nanoaperture array can be controlled by simply varying the electrodeposition time. As a proof-of-principle demonstration of the fabrication method, we fabricated waveguide arrays (300 μm x 300 μm) onto standard microscope cover glasses with diameters ranging from 70±20 nm to 1000±17 nm (mean±std, as determined by SEM). To determine the attenuation of the excitation light within the ZMWs we characterized the fluorescence emission as a function of diameter (D) and found that it is proportional to D3.4 in the zero-mode regime (where no modes can propagate), D2.35 in the transition regime (modes increasingly propagate as a function of diameter), and D∼2 in the super-wavelength regime (all modes exist). In addition, we have directly observed the diffusion of single molecules at a solution concentration of 1 μM. These results demonstrate that our fabrication method can produce usable waveguide geometries using low-cost processing techniques.
One- and two-photon spectroscopy of Eu3+ in LuPO4

Abstract One-photon laser excitation and fluorescence spectra have been recorded for the Eu 3+ ion diluted in single crystals of LuPO 4 . Analysis of these spectra resulted in the assignment of 23 energy levels of the 7 F J and 5 D J multiplets, which were fitted to the parameters of an empirical Hamiltonian with an rms deviation of 8.7 cm −1 . The intensities of the two-photon absorption transitions to the 5 D 0 and 5 D 2 multiplets have been investigated. The polarization dependences of transitions to all five of the crystal-field levels were measured and are compared with theoretical predictions. The intensity model included the third-order spin–orbit interaction. Good agreement was found for three of the five transitions observed. However, the polarization dependences of the other two did not agree with the predicted behavior, as they exhibited an additional isotropic component.
Development of bioactive peptide amphiphiles for therapeutic cell delivery

Abstract There is great clinical interest in cell-based therapies for ischemic tissue repair in cardiovascular disease. However, the regenerative potential of these therapies is limited due to poor cell viability and minimal retention following application. We report here the development of bioactive peptide amphiphile nanofibers displaying the fibronectin-derived RGDS cell adhesion epitope as a scaffold for therapeutic delivery of bone marrow derived stem and progenitor cells. When grown on flat substrates, a binary peptide amphiphile system consisting of 10 wt.% RGDS-containing molecules and 90 wt.% negatively charged diluent molecules was found to promote optimal cell adhesion. This binary system enhanced adhesion 1.4-fold relative to substrates composed of only the non-bioactive diluent. Additionally, no enhancement was found upon scrambling the epitope and adhesion was no longer enhanced upon adding soluble RGDS to the cell media, indicating RGDS-specific adhesion. When encapsulated within self-assembled scaffolds of the binary RGDS nanofibers in vitro, cells were found to be viable and proliferative, increasing in number by 5.5 times after only 5 days, an effect again lost upon adding soluble RGDS. Cells encapsulated within a non-bioactive scaffold and those within a binary scaffold with scrambled epitope showed minimal viability and no proliferation. Cells encapsulated within this RGDS nanofiber gel also increase in endothelial character, evident by a decrease in the expression of CD34 paired with an increase in the expression of endothelial-specific markers VE-Cadherin, VEGFR2 and eNOS after 5 days. In an in vivo study, nanofibers and luciferase-expressing cells were co-injected subcutaneously in a mouse model. The binary RGDS material supported these cells in vivo, evident by a 3.2-fold increase in bioluminescent signal attributable to viable cells; this suggests the material has an anti-apoptotic and/or proliferative effect on the transplanted bone marrow cells. We conclude that the binary RGDS-presenting nanofibers developed here demonstrate enhanced viability, proliferation and adhesion of associated bone marrow derived stem and progenitor cells. This study suggests potential for this material as a scaffold to overcome current limitations of stem cell therapies for ischemic diseases.
Rehospitalizations after coronary revascularization among medicare beneficiaries

The rehospitalization experience of Medicare beneficiaries undergoing coronary artery bypass surgery or percutaneous transluminal coronary angioplasty in 1986 and 1987 was studied by following 53,715 patients who underwent coronary artery bypass and 28,817 patients who underwent angioplasty for 1 year using Medicare hospital claims data. The 1-year rehospitalization rate after bypass and angioplasty was 629 and 863 per 1,000, respectively, compared to a rate of 607 for the Medicare patient population in general. About 45% of rehospitalizations after bypass and two thirds after angioplasty were in categories determined by an expert panel to be possibly related to the original procedure. After angioplasty, there were 61 discharges per 1,000 for bypass surgery and 140 per 1,000 for a repeat angioplasty. Rehospitalization rates for coronary artery bypass surgery after angioplasty were significantly lower for female and black patients who underwent angioplasty. The volume of rehospitalization after revascularizations makes it an important outcome measure. Medicare administrative records provide a unique source of information on rehospitalizations and make possible the monitoring of broad trends in the frequency and outcomes of coronary revascularization. The lower rates of bypass surgery after angioplasty for black and female patients are in line with other studies and bear further investigation.
Modelling Cr(VI) reduction by pure bacterial cultures

Cr(VI) reduction data obtained with three bacterial species (Escherichia coli ATCC 33456, Bacillus sp., Pseudomonas fluorescens LB 300) were analyzed using an enzyme-based kinetic model. The model was developed by incorporating enzyme kinetics and a finite Cr(VI) reduction capacity to illustrate toxic effects of Cr(VI). The model was also used to analyze Cr(VI) reduction data taken from the literature for two other Cr(VI)-reducing species (Desulfovibrio vulgaris ATCC 29579, and Pseudomonas ambigua G-1). Although our different genera of bacteria were involved, the model was found to be capable of describing Cr(VI) reduction. The finite capacity indicates the maximum amount of Cr(VI) that a batch culture can reduce and it was explicitly demonstrated regardless of subsequent cell growth. The lost of Cr(VI) reduction capacity in bacterial cells may be attributed to the mutagenic and toxic effects of Cr(VI). The batch cultures reduced Cr(VI) at rates which decreased progressively with the amount of Cr(VI) reduced. Cr(VI) reduction ceased whenever the maximum capacity was reached.
Voice and relativization without movement in Malagasy

Major syntactic processes in Malagasy (Madagascar) are conditioned by its rich, typically W. Austronesian, voice system. This is true of the formation and interpretation of relative clauses, focus constructions, nominalizations, control structures, imperatives, the distribution of reflexives, and more. Similar claims hold to varying extents in related languages. Limiting ourselves to Malagasy, we derive, and compositionally interpret, nuclear Ss headed by verbs in different voices. Such Ss are directly projected from verbal affixes, not derived by A or A′ movement, contra other approaches. We derive relative clauses (RCs) directly from predicates in different voices. No operator movement is needed or used. We compositionally interpret RCs, which only requires interpreting predicates in different voices but not variable binding operators or bound variables. This yields a new analysis of the “Subjects Only” constraint in Malagasy. Further, Malagasy’s rich voice system suggests a cognitive trigger for the use of variable binding operators in RCs in voice-poor languages such as English.
An update of the isolation and characterization of culture-derived soluble antigens of Babesia bovis

In this paper recent progress concerning the identification of soluble antigens from cultures of Babesia bovis parasites is reviewed. Soluble antigens present in the supernatant of B. bovis cultures have been shown to be efficient immunogens for induction of protective immunity against bovine babesiosis. Immunochemical analysis of culture supernatants has demonstrated that at least 3 parasite antigens are released in vitro. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that at least 2 of these antigens have molecular weights within the range of 37 000-40 000 daltons. Crossed immunoelectrophoretic studies have further revealed an antigenic spectrum consisting of 1 major and 2 minor antigens with mobilities in the albumin and alpha 1 regions. Within the infected erythrocyte, 2 antigens have been localized on or near the erythrocytic membrane, while the third antigen appears to be directly associated with the parasite.
REFLECTING ON THE USE OF METAPHOR: TWO PROFESSORS' PROCESSES OF DISCOVERY

This article summarizes the literature concerning the use of visual and textual metaphors and describes outcomes of a project designed to help teacher education candidates begin integrating their personal beliefs about teaching with their growing professional knowledge and emergent practice. By using metaphors, teacher educators have the opportunity to help candidates solidify convictions and meanings and uncover “tacit or unarticulated” beliefs (Clandinin & Connelly, 1995, p. 6) that can lead to frame conflict (Reddy, 1993), that is, dueling metaphors. For example, there is a frame conflict in the conception of student value in the metaphors of teacher-as-police-officer and teacher-as-gardener. In one metaphor, students are perceived as deficit “others” who must be carefully watched by authorities; in the gardening metaphor, student potential is recognized as “more than” what can be seen on the surface. This article demonstrates how one university faculty explores textual and visual metaphor to encourage...
Phenotype profile of a genetic mouse model for Muenke syndrome

The Muenke syndrome mutation (FGFR3 P250R ), which was discovered 15 years ago, represents the single most common craniosynostosis mutation. Muenke syndrome is characterized by coronal suture synostosis, midface hypoplasia, subtle limb anomalies, and hearing loss. However, the spectrum of clinical presentation continues to expand. To better understand the pathophysiology of the Muenke syndrome, we present collective findings from several recent studies that have characterized a genetically equivalent mouse model for Muenke syndrome (FgfR3 P244R ) and compare them with human phenotypes. FgfR3 P244R mutant mice show premature fusion of facial sutures, premaxillary and/or zygomatic sutures, but rarely the coronal suture. The mice also lack the typical limb phenotype. On the other hand, the mutant mice display maxillary retrusion in association with a shortening of the anterior cranial base and a premature closure of intersphenoidal and spheno-occipital synchondroses, resembling human midface hypoplasia. In addition, sensorineural hearing loss is detected in all FgfR3 P244R mutant mice as in the majority of Muenke syndrome patients. It is caused by a defect in the mechanism of cell fate determination in the organ of Corti. The mice also express phenotypes that have not been previously described in humans, such as reduced cortical bone thickness, hypoplastic trabecular bone, and defective temporomandibular joint structure. Therefore, the FgfR3 P244R mouse provides an excellent opportunity to study disease mechanisms of some classical phenotypes of Muenke syndrome and to test novel therapeutic strategies. The mouse model can also be further explored to discover previously unreported yet potentially significant phenotypes of Muenke syndrome.
Early life mortality rates and mortality rate ratios among singleton and multiple births, five subgroups of Hispanics in Illinois (1989-1992).1631

In the next decade every third neonate born in the U.S. will be of Hispanic origin. 1989-1992 birth death linked files and fetal death records were analyzed, Chi square was used with two sided probability value of less than 0.05 to evaluate statistical significance and odds ratios and RR were calculated for mortality rate ratios for multiple/single mortality indices. Race/ethnicity was determined by maternal listing of her ethnicity on birth certificate. Neonates weighing <500 grams and <20 weeks gestation were excluded and mortality indices were calculated for 1000 births. Multiple/single mortality rate ratios were compared for each subgroup with the remaining four subgroups. Conclusion: Multiple birth mortality risk ratios were significantly elevated for fetal, neonatal and postneonatal, perinatal and infant births for the Mexican and South/Central American Hispanic subgroups. Table
Word length and rarity in recognition memory

Operating characteristics were used to assess the importance of word-frequency and word-length in recognition memory. It was much easier for Ss to distinguish between old and new rare words than between old and new common words. Rare (but not common) words were easier to recognize when they were polysyllabic than when they were not.
Spatiotemporal Genetic Structure within White Clover Populations in Grazed Swards

White clover (L.) populations exhibit high genetic and clonal diversity, but often exist for many decades in grazed swards at northern midlatitudes. This study was conducted to determine whether genetic structure exists within rapidly changing populations and is a factor in creating genetic diversity. Trifoliate leaf samples were taken monthly in 1997 and 1998 from up to 37 specific points in four 1.2- by 1.2-m quadrats from May to September on two central Pennsylvania farm sites. Random amplified polymorphic DNA (RAPD) profiles of population samples from 67 quadrats were tested by spatial autocorrelation analysis based on a multivariate nonparametric approach. Significant (< 0.05) overall spatial autocorrelation was found in 26 populations that had clones and in seven populations without clones, while nonsignificant autocorrelation was found in 27 and seven populations with and without clones, respectively. Frequencies of significant autocorrelation for populations on one site in 1997 and 1998 were 0.5 and 0.2, respectively, and the frequencies for the other site were 0.8 and 0.4, respectively. The ratio of populations lacking significant autocorrelation to those with significant autocorrelation changed little from zero to six clones, but increased dramatically for seven or eight clones. The estimated patch size (overall mean 66 cm; SE = 8) for two years and two sites did not change significantly over the growing season. Number of clones and patch size was less important in determining genetic structure than variable existence of spatial autocorrelation.
Deformation evolution during initiation of transgranular stress corrosion cracking

Face centered cubic metals and alloys have multiple slip systems and are characterized by high dislocation velocities. Nevertheless, these materials suffer from transgranular stress corrosion cracking (T-SCC), that occurs by environmentally-induced cleavage. Since plasticity precedes fracture in all T-SCC phenomena, the evolution of deformation patterning during T-SCC is an important element of the local microfracture mode. Experimental observations show that the presence of the SCC-causing environment during straining is promoting localized plastic deformation at the near-surface region and producing an entirely different deformation pattern compared with that developing in laboratory air. The deformation evolving in the presence of the SCC electrolyte is highly localized, exhibiting closely spaced, coarse slip bands. The amount of localized strain developing at the near-surface region prior to nucleation of stress corrosion cracks is equivalent to the strain required for ductile fracture of the material in air, suggesting the existence of a fundamental fracture criterion. The above phenomenology of the deformation evolution is considered in relation to T-SCC initiation and propagation. The T-SCC is suggested to be a macroscopically brittle but microscopically ductile fracture occurring by localized plastic flow. An environment-induced deformation localization mechanism is described where the role of the environment involves generation of vacancies and subsequent dislocation nucleation from the near-surface region at loads well below those required for normal yielding. The evolution of the localized deformation pattern during T-SCC is suggested to be an outcome of nonuniformity and periodicity in the dissolution process.
Arthroscopic treatment of calcaneonavicular coalition in children

Calcaneonavicular coalition is a common source of pain and more or less severe flat and stiff foot in children. Classically, treatment consists in resecting the coalition using a dorsolateral approach. Good quality resection and interposition can prevent recurrence. The most common complications are infection, hematoma and neuroma. Arthroscopy offers a minimally invasive alternative, but the optimal approach remains undetermined. We describe a surgical technique with an approach based on the anterolateral process of the calcaneus, in three cases with 12 months' follow-up. Arthroscopic resection has certain advantages: recovery is quicker, and the esthetic result is better. For the instrumental portal, skin incision should be superficial, followed by blunt dissection of subcutaneous tissue to avoid superficial peroneal nerve injury. Although longer term follow-up is needed, arthroscopy seems to be an attractive minimally invasive technique in this kind of pathology.
Surgical reconstruction of tracheal stenosis in conjunction with congenital heart defects.

Background Surgical reconstruction is the primary method of treating airway obstruction in children. Tracheal stenosis is frequently associated with congenital heart defects, which may further complicate the overall management strategy. The purpose of this study was to review our experience with surgical reconstruction of airway obstruction in conjunction with congenital heart defects. Methods This was a retrospective review of our surgical experience with tracheal stenosis from February 2003 to August 2011. Twenty-seven patients were identified in our database. Six patients had isolated, congenital tracheal stenosis, and 21 had tracheal stenosis in association with congenital heart defects. There were two identifiable subgroups. Thirteen patients had airway stenoses identified concurrently with congenital heart defects and underwent combined repair. The second group comprised 8 patients who had previous correction of their congenital heart defects and experienced delayed presentation of tracheal (n = 6) or bronchial (n = 2) obstruction. Results The median age at surgery was 9 months. There were 2 postoperative deaths, both in children with single ventricle. The median duration of follow-up for the entire cohort of 25 surviving patients was 4 years. None of the patients have required reoperations on the trachea; 5 have had minor reinterventions. Conclusions The data demonstrate that tracheal obstruction is frequently found in conjunction with congenital heart defects. Nearly one third of our patients had delayed presentation of airway obstruction that was identified subsequent to previous congenital heart defect repair. Tracheal reconstructive techniques were effective regardless of the cause of the airway obstruction.
Spin-down of an oblique rotator with a current-starved outer magnetosphere

A variant of the vacuum-dipole model of rotation-powered pulsars is presented that accounts for the observed spin-down properties of all three pulsars with braking indices measured from absolute pulse numbering (the Crab, PSR B0540 -69 and PSR B1509 -58). In the model, the neutron star and inner magnetosphere are treated phenomenologically as a single unit, a magnetized, perfectly conducting sphere of radius rv rotating rigidly in vacua. The 'vacuum radius' rv corresponds to the innermost point in the magnetosphere where field-aligned flow breaks down and the plasma becomes three-dimensional, that is, the point where cyclotron losses occur slowly enough to allow electrons (or positrons) to move an appreciable distance before decaying to the l = 0 Landau state. For young, Crab-like pulsars, one typically finds r* ≪ rv <L, where r* is the stellar radius, and rL is the light-cylinder distance. The model therefore differs from standard vacuum-dipole theories, in which the dipole has radius r* and is treated as point-like. Three observable pulsar parameters - the rotation frequency ω, its time derivative ω, and the angle α between the rotation and magnetic axes - uniquely determine rv and hence the electromagnetic braking torque exerted on the star, calculated from the Deutsch radiation fields of the rotating dipole. With no free parameters, the theory yields braking index values n = ωω/ω2 for the Crab, PSR B0540-69 and PSR B1509-58 that agree with timing data to 4 per cent. The second deceleration parameter m = ω2ω/ω3 is also predicted for each object, but cannot be verified to useful precision using data available at present. The relationship between our idealized yet successful spin-down model and a genuine pulsar magnetosphere is discussed, and further observational tests of the theory are proposed. © 1997 RAS.
Polysubstance Use Among Alcoholics

Contemporary alcoholics often use multiple substances, but there is little systematic research on this. This study examines the drug use comorbidity of alcoholics (DSM diagnosis, frequency and quantity of drug use); the relationship between drinking and drug use; the relative severity of alcohol- and drug-related problems; and the validity of reports of illicit drug use. Data on substance use were collected from 248 treatment-seeking alcoholics using an expanded Time-line Follow-Back (TLFB) interview. Self-reports of substance use were validated with data from biological specimens (urine and hair). Lifetime diagnosis of joint alcohol and drug dependence/abuse was 64%. Two-thirds (68%) reported using drugs in the past 90 days: 33% powder cocaine; 29% crack cocaine; 15% heroin, and 24% cannabis. The mean proportions of exposed days on which users reported consuming a substance were 57% (alcohol), 26% (powder cocaine), 46% (crack cocaine), 47% (heroin), and 29% (cannabis). Subjects reported consuming an average of 14 standard drinks on a drinking day and $67 worth of drugs on a using day. Drug users reported drinking less than nonusers on a drinking day. Frequency of drinking and drug use were positively correlated; almost all drug users reported simultaneous drinking and drug use; and they rated drugs as the bigger problem. Considerable under-reporting of drug use occurred for the previous 3-4 days, but was more accurate for the previous month.
Growth hormone and fibronectin expression in 3T3 preadipose cells.

In the present study we focused on the relationship between GH action and the extracellular matrix in 3T3-F442A preadipose cells. Results from Northern blotting indicated that in serum-free medium, the presence of 2 nM met-human GH down-regulated levels of fibronectin messenger RNA by approximately 40, 60, and 70% as compared with control levels on days 1, 2, and 4, respectively. GH-dependent reduction of levels of collagen alpha 1(I) mRNA expression occurred later and was less pronounced than effects on levels of fibronectin mRNA, suggesting a specificity in the matrix-altering function of GH. Western blot analyses and immunoprecipitation studies revealed that between 2 and 5 days of culture, matrix-associated fibronectin protein was reduced 70 to 90% by GH treatment. Down-regulation of fibronectin protein expression by met-human GH was dose-dependent between 2 and 0.02 nM. The presence of 2 nM insulin or insulin-like growth factor-1 promoted a 30-40% increase in fibronectin levels compared to control ce...
United States’ Narco‐Terrorism Policy: A Contingency Approach to the Convergence of the Wars on Drugs and Against Terrorism

In recent years, terrorist organizations have become increasingly dependent on drug trafficking as one of several primary sources of revenue to fund terrorist activities. In response, the United States’ security and intelligence efforts against narco-terrorism have increasingly merged into one unified policy approach. Moreover, the convergence of United States policy wars against terrorism and illicit drugs have produced complex and dynamic contingency factors. As a result, a relatively coherent nexus now exists between the United States’ antinarcotics and antiterrorist policies. The objective of this article is to explain and assess the contingency factors and implications resulting from this convergence and to provide policy scholars with an analytical perspective into the implications of the United States’ narco-terrorism policy. It is believed that this article is significant to both policy practitioners and policy scholars concerned with the domestic impact of the United States’ narco-terrorism policy.
The measurement of quality of life in adolescence: The quality of student life questionnaire

Abstract The Quality of Student Life Questionnaire (QSLQ) may be of particular use to family therapists attempting to understand the perceptions of adolescents within family constellations. The QSLQ is comprised of four factors: Satisfaction, Well-Being, Social Belonging, and Empowerment/Control. The Questionnaire is reliable, unobtrusive, and non-clinical–making it appropriate for use with normal adolescents. The QSLQ is described and preliminary data on its psychometric characteristics are presented.
The iron transporter Fth1p forms a complex with the Fet5 iron oxidase and resides on the vacuolar membrane.

Iron transport across the plasma membrane appears to be a unidirectional process whereby iron uptake is essentially irreversible. One of the major sequestration sites for iron is the vacuole that stores a variety of metals, either as a mechanism to detoxify the cell or as a reservoir of metal to enable the cell to grow when challenged by a low iron environment. Exactly how the vacuole contributes to the overall iron metabolism of the cell is unclear because mutations that affect vacuolar function also perturb the assembly of the plasma membrane high affinity transport system composed of a copper-containing iron oxidase, Fet3p, and an Fe3+-specific iron transporter, Ftr1p. Here, we characterize the iron transporter homologue Fth1p, which is similar to the high affinity plasma membrane iron transporter Ftr1p. We found that Fth1p was localized to the vacuolar surface and, like other proteins that function on the vacuole, did not undergo Pep4-dependent degradation. Co-immunoprecipitation experiments showed that Fth1p also associates with the Fet3p oxidase homologue, Fet5p; and disruption of the FET5 gene results in the accumulation of Fth1p in the endoplasmic reticulum. We also found that loss of this protein complex leads to elevated transcriptional activity of the FET3 gene and compromises the ability of the cell to switch from fermentative metabolism to respiratory metabolism. Because the Fet5 protein is oriented such that the oxidase domain of Fet5p is lumenal, this complex may be responsible for mobilizing intravacuolar stores of iron.
Cell cycle-specific changes in β-adrenergic receptor concentrations in C6 glioma cells

Abstract The concentration of β-adrenergic receptors in synchronized C6 cells is lowest during mitosis and G 1 (1000–2000 receptors/cell). A rapid increase in β-receptor concentration occurs in early S phase to 9000 receptors/cell, followed by a decrease during G 2 to the low concentration found at mitosis. In non-synchronized C6 cell populations, mitotic cells have one-half of the average β-receptor concentration of the population as a whole, confirming the observations made with synchronized cells.
Spatial Relation between Microbleeds and Amyloid Deposits in Amyloid Angiopathy

Advanced cerebrovascular β-amyloid deposition (cerebral amyloid angiopathy, CAA) is associated with cerebral microbleeds, but the precise relationship between CAA burden and microbleeds is undefined. We used T2*-weighted MRI and noninvasive amyloid imaging with Pittsburgh Compound B (PiB) to analyze the spatial relationship between CAA and microbleeds. On co-registered PET and MRI images, PiB retention was increased at microbleed sites compared to simulated control lesions (p=0.002) and declined with increasing distance from the microbleed (p<0.0001). These findings indicate that microbleeds occur preferentially in local regions of concentrated amyloid and support therapeutic strategies aimed at reducing vascular amyloid deposition.
On the competition between hydrogen abstraction versus C-O bond fission in initiating dimethyl ether combustion

Abstract There are two initiation steps involved in the combustion of dimethyl ether (DME), one involving C-O bond fission and the other involving hydrogen abstraction by molecular oxygen. The kinetics and thermodynamics of C-O bond fission were explored computationally in a previous paper. The present paper addresses the competing process—hydrogen abstraction by molecular oxygen. Ab initio molecular orbital calculations are used to study the structures and energetics of the reactants, products, and the transition state for the CH3OCH3 + O2 reaction. The calculations predict a barrier for hydrogen abstraction from CH3OCH3 by O2 of 47.4 kcal mol−1. This is lower than the barrier height for C-O bond fission previously calculated to be 81.1 kcal mol−1. The results support values used in current models for the combustion of DME. Moreover, an examination of rates for C-O bond fission versus hydrogen abstraction by O2 suggests that the bimolecular process is the dominant pathway.
RECOUNTING FEDERAL POLICY ON TRANSIT OPERATING ASSISTANCE

Federal involvement in financing the nation's public transit services grew from several small demonstration programs in the early seventies to a massive $1.1 billion commitment by the end of the decade. The Reagan Administration's proposal to eliminate all operating subsidies by the mid-eighties, however, marks a sharp departure in federal philosophy, and has rekindled the seemingly perennial debate on what the federal role should be. The evolution of federal subsidy policies and underlying rationales for them are retraced in this article. From a survey of local and state officials, a general consensus emerged that about twelve percent of transit's total benefits accrue to the nation as a whole, suggesting a comparable level of federal responsibility for financing transit services. The ascendency of a responsible program of transit cost-sharing has been hindered, it is suggested, by the absence of a unitary position on what the nation hopes to get out of public transit services.