cssi/SciSciGPT-SciSciNet huggingface dataset:
An asymptotically compatible treatment of traction loading in linearly elastic peridynamic fracture

Abstract Meshfree discretizations of state-based peridynamic models are attractive due to their ability to naturally describe fracture of general materials. However, two factors conspire to prevent meshfree discretizations of state-based peridynamics from converging to corresponding local solutions as resolution is increased: quadrature error prevents an accurate prediction of bulk mechanics, and the lack of an explicit boundary representation presents challenges when applying traction loads. In this paper, we develop a reformulation of the linear peridynamic solid (LPS) model to address these shortcomings, using improved meshfree quadrature, a reformulation of the nonlocal dilatation, and a consistent handling of the nonlocal traction condition to construct a model with rigorous accuracy guarantees. In particular, these improvements are designed to enforce discrete consistency in the presence of evolving fractures, whose a priori unknown location render consistent treatment difficult. In the absence of fracture, when a corresponding classical continuum mechanics model exists, our improvements provide asymptotically compatible convergence to corresponding local solutions, eliminating surface effects and issues with traction loading which have historically plagued peridynamic discretizations. When fracture occurs, our formulation automatically provides a sharp representation of the fracture surface by breaking bonds, avoiding the loss of mass. We provide rigorous error analysis and demonstrate convergence for a number of benchmarks, including manufactured solutions, free-surface, nonhomogeneous traction loading, and composite material problems. Finally, we validate simulations of brittle fracture against a recent experiment of dynamic crack branching in soda-lime glass, providing evidence that the scheme yields accurate predictions for practical engineering problems.
The Role of Chemotherapy in Head and Neck Malignancy

SUMMARY Despite 20 years of active investigation, the role of chemotherapy for head and neck malignancies remains largely undefined and continues to be an area for active investigation. Clearly, for patients with recurrent and metastatic disease, palliation can be achieved, with single agent methotrexate being the standard for SCC H & N. Primary chemotherapy still remains largely experimental, except for patients with advanced laryngeal carcinoma. For patients with advanced resectable SCC H & N, new combinations that can achieve greater than 50% complete response rates with acceptable toxicity remain the goal. The concurrent use of chemotherapy and radiation appears promising with survival advantages noted for patients with unresectable SCC H & N. Organ preservation without compromising survival has been noted for advanced laryngeal primaries and is now under active investigation for other sites of disease in the head and neck. The use of intra-arterial chemotherapy may play a role in this regard, particularly for patients with maxillary sinus tumors. The area with the most promise is chemoprevention, with the retinoids showing an impact on reducing second primary aerodigestive tract tumors. New chemopreventive agents and analogues are currently being developed, with combined chemopreventive agent trials forthcoming. Continued emphasis must concurrently be placed on smoking cessation along with these trials.
Deformation behavior of a model high entropy alloy from atomistic simulations

Abstract This paper reports atomistic simulation studies of deformation behavior in a model quinary high entropy FCC alloy. The simulations are based on empirical interatomic potentials and use massively parallel molecular dynamics techniques at the atomistic level to study the deformation mechanisms. The studies consider columnar polycrystalline samples containing pure tilt grain boundaries with random misorientations around the [110] crystallographic axis. Virtual tensile tests were performed and the material response analyzed using various techniques, focusing on the role that the local composition in the random alloy plays in the deformation mechanisms. Overall plastic response correlates well with the values of unstable stacking faults given by the potential, and it is therefore not meaningful to compare deformation response with that of any of the single components. The more meaningful comparison is with a corresponding “average atom” material that has the same average properties but no local randomness. The main effect of the random composition fluctuations is to make dislocation glide more difficult. These fluctuations also result in lower twin to stacking fault ratios in the deformed samples. The complex high entropy alloy presents a higher strength, and overall less plastic deformation for the same levels of stress. This is mostly driven by the fact that the dislocations emitted from the grain boundaries do not glide as easily in the random alloy as they do in the average atom material.
YADA: Yet Another Distributed Architecture for Real-Time Robotic Control Systems

This paper presents YADA, a new software architecture for real-time robotic control systems that is minimal, modular, and fully transparent. YADA divides control software into decoupled behavior, user-interface, and hardware-level bus modules. This decoupling at the module level is accomplished by auto-generating human-readable message types that are tailored to the hardware topology oft he current system. These message types provide modules with a common framework for exchanging state information and relaying commands to devices while being agnostic to the communication protocol itself. We also detail how to structure behavior and bus modules to facilitate modularity and flexibility with third party software. YADA has been used with success on several technology development testbeds at JPL, an example of which is given in this paper, and has proven to provide developers a light-weight and highly reconfigurable system for efficient debugging and practical code sharing
Glasses Versus Observation for Moderate Bilateral Astigmatism in 1- to <7-Year-Olds.

PURPOSE To compare visual outcomes in children with moderate bilateral astigmatism treated with glasses with those who were merely observed. DESIGN Retrospective case series. METHODS The medical records of all children 1 to <7 years of age who were diagnosed with moderate bilateral astigmatism (+1.25 to +3.25 diopters [D]) at a single institution over a 12-year period were retrospectively reviewed. Children with anisometropia ≥1.00 D, hyperopia ≥+3.00 D, myopia ≥-3.00D, amblyopia, or strabismus at diagnosis were excluded. Observation or full spectacle correction of astigmatism was at the provider's discretion. Kaplan-Meier rates of developing amblyopia and strabismus were assessed over a minimum follow-up of 18 months. RESULTS Eighty-five (6.9%) of 1235 subjects met the inclusion criteria; 58 (68.2%) were prescribed glasses while 27 (31.8%) were observed. The groups differed by mean age at diagnosis (3.56 ± 1.42 years for observed vs 4.31 ± 1.36 years for glasses [P = .03]) and mean amount of astigmatism (1.73 ± 0.43 D for observed vs 2.00 ± 0.51 D for glasses [P = .02]). By 4 years of follow-up, the Kaplan-Meier rate of developing amblyopia was 8.3% (95% confidence interval [CI] 0%-19.4%) in the observed group and 10.3% (95% CI 1.5%-19.1%) in the glasses group [P = .74] while strabismus was 7.1% (95% CI 0%-20.6%) among those observed and 7.1% (95% CI 0.4%-13.8%) of those prescribed glasses [P = .60]. CONCLUSIONS Rates of amblyopia and strabismus were similar and modest in this cohort of children with moderate bilateral astigmatism treated with glasses vs observation. These results suggest that prescribing glasses for these children may be no better than observation in preventing the development of amblyopia or strabismus.
The equine mesenchymal stromal cell secretome inhibits equid herpesvirus type 1 strain Ab4 in epithelial cells.

Abstract Equid herpesvirus 1 (EHV-1) outbreaks occur when virus spreads from infected horses to in-contact horses, primarily via nasal shedding. This study evaluated the efficacy of factors secreted by equine peripheral blood derived mesenchymal stromal cells (PB-MSCs), collectively named the secretome, to inhibit the growth of EHV-1 in (i) 2D epithelial cell cultures (RK-13) in vitro, (ii) 3D equine nasal explants in vitro and (iii) an EHV-1 infection mouse model in vivo. The PB-MSC secretome was found to inhibit EHV-1 in RK-13 cells as well as in the epithelium of equine nasal explants. Although the PB-MSC secretome did not decrease overall severity of EHV-1 infection in mice, as determined by weight loss and viral titers in lungs, histological analyses indicated local reduction of EHV-1 infection in nasal epithelium. These results indicate that the PB-MSC secretome inhibits EHV-1 in epithelial cells in a context-dependent manner.
Enhanced Engine Control for Emergency Operation

C-MAPSS40k engine simulation has been developed and is available to the public. The authenticity of the engine performance and controller enabled the development of realistic enhanced control modes through controller modification alone. Use of enhanced control modes improved stability and control of an impaired aircraft. - Fast Response is useful for manual manipulation of the throttles - Use of Fast Response improved stability as part of a yaw rate feedback system. - Use of Overthrust shortened takeoff distance, but was generally useful in flight, too. Initial lack of pilot familiarity resulted in discomfort, especially with yaw rate feedback, but that was the only drawback, overall the pilot found the enhanced modes very helpful.
Other Tropical Mountains

The outline of the outstanding characters of the high altitude ecology of the mountains of the tropical regions, contained in this chapter, serves to illustrate the influence of local conditions on the high altitude environment and emphasize, at the same time, the fundamental differences from the high altitude ecology of the north and south temperate regions of the world.
Optical Flow Computation in the Presence of Spatially-Varying Motion Blur

While most of the techniques for inferring optical flow are based on the brightness constancy assumption, various conditions including the presence of motion blur evidently violate this fundamental presumption. If the source image and the target image appear to be dissimilar due to different blur kernels, traditional methods will fail to achieve accurate results. We present a new method, MB-CLG, that considers constructing a new pair of blurred frames, followed by regular optical flow computation. The proposed method employs a coarse-to-fine approach, in conjunction with a smoothness matrix to account for occluded regions. Rather than warping frames or precomputing a large grid of derivatives, MB-CLG warps the flows at each iteration. This leads to lower computational cost, and requires less data storage. Based on the results for various sequences, MB-CLG outperforms existing optical flow methods in the sense of AAE, AEP and MSE.
Radiation sources and detectors

Some characteristics of radiation sources, such as X-rays, electrons, protons, and neutrons used in the nondestructive testing of material, are presented. Detailed information on the quality of inspection possible with X-rays is also presented. The different types of detectors such as ionization chambers and solid-state detectors are briefly reviewed, while a detailed presentation is made of the characteristics of film. The capability of the radiographic system as described in specifications is presented as the measuring base for competitive methods of image analysis in nondestructive test systems.
The structure of specific genes in chromatin.

Publisher Summary This chapter describes the attempts to relate structural changes to changes in the template activity of the nucleoprotein complex that require one to considers all discernible levels of structure in the hierarchical organization of the chromosome. The smallest unit examined in the studies are the nucleoprotein fragments generated upon cleavage of the nucleosome itself. These fragments of precisely determined lengths perhaps represent the points of intimate association of histones with DNA. The specific organization of these fragments generates the larger basic subunit or nucleosome. Although the precise nature of the interaction between DNA and protein in the nucleosome remains unclear, current physicochemical studies support the view that the DNA resides on the external surface of an apolar core of specific histone aggregates. The chapter reviews that analysis of the distribution of nucleosomes over transcribing sequences reveals that the template-active regions of the genome are similarly organized in this basic structure. The mere presence of nucleosomes along a given sequence is not sufficient to restrict transcription. It is possible that regulatory factors exert their effect by recognizing specific sites within a preformed subunit. In accord with this, it is found that specific nucleotide sequences within the core of the nucleosome can be identified and cleaved by restriction endonucleases that require sequence recognition for activity. It is further possible that the aspects of DNA structure dictated by nucleosomal organization are required for the fidelity of regulatory interactions.
A simplified and efficient system for separating proteins by preparative polyacrylamide electrophoresis. With notes on horse heart myoglobin.

Abstract A simplified but effective method for preparative polyacrylamide gel electrophoresis is presented, suitable for single runs of ∼15 mg of protein, which allows: (1) a gel casting shaped and cooled so that proteins do not assume curvature as they migrate down the column; (2) direct contact of the bottom of the gel with buffer; (3) use of reduced electrical field since anode and cathode are spaced only 9.5 cm apart; (4) increased stability of the anodal face of the gel, by employing a dilute running buffer and consequently a still lower current (7 to 8 mA at 150 V); (5) obtaining successive effluents in separate Visking sacs, at appropriate time intervals, and removal of proteins in absence of an electrical field; (6) rinsing of the column between collections; (7) advance planning of the actual times of collection, calculated from the rates of migration of proteins of interest relative to the time of passage of (yellow) “myoglobin standard” determined in analytical columns run under the same conditions. Working conditions are designed to eliminate gel deformations during electrophoresis. Individual effluents and rinsings are dialyzed and concentrated by negative pressure in a simple device.
Re‐discovering Barnard: the functions of the … leader?

Purpose – The purpose of this paper is to highlight Barnard's groundbreaking ideas, and to interpret his contributions to the philosophy and practice of business as they apply to the twenty‐first century executive.Design/methodology/approach – The paper makes use of primary data by focusing on Barnard's The Functions of the Executive, as well as other material written by, and about, him. Barnard's insights on executive management are then reinterpreted in light of Ramey's Leadership Quality Commitments, whose balance is deemed an essential marker of success for twenty‐first century leaders.Findings – The paper presents Barnard as a pioneer philosopher in the field of management, whose rich contributions have permeated management theory and practice since he first published his seminal work 71 years ago. Barnard's concept of cooperation is re‐discovered as the basis of a leadership framework that places the executive at the center of a system responsible for balancing an unstable equilibrium among life, wo...
La relation entre les dépenses et les recettes publiques dans une économie régionale : le Québec, 1955-82

La croissance des depenses publiques mene-t-elle a une augmentation des revenus ou est-ce la croissance des revenus provinciaux qui fait augmenter les depenses publiques? De recentes etudes ont demontre qu’il y a une dependance mutuelle entre les depenses publiques et le PNB. Ces resultats ont des implications evidentes pour les politiques et les previsions economiques. Les auteurs du present article se demandent si ces resultats sont valables pour une economie regionale (tel qu’une province faisant partie d’une confederation) ou les depenses et les recettes publiques dependent directement et indirectement d’un bon nombre d’accords et de programmes negocies avec le gouvernement federal. Cette etude demontre que meme dans un contexte regional, il existe une relation avec feedback entre ces deux variables. Ainsi, la croissance des depenses publiques et celle des revenus provinciaux au Quebec se renforcent mutuellement en depit des facteurs exogenes. Les auteurs suggerent donc que le choix des politiques economiques se fasse dans un contexte plus global ou l’on tiendrait compte de cette dependance mutuelle.
Novel roles of local insulin-like growth factor-1 activation in gastric ulcer healing: Promotes actin polymerization, cell proliferation, re-epithelialization, and induces cyclooxygenase-2 in a phosphatidylinositol 3-kinase-dependent manner

The precise role of insulin-like growth factor (IGF)-1 in gastric ulcer healing is unknown. In experimental rat gastric ulcers, we examined expression of IGF-1 mRNA and protein by reverse transcriptase-polymerase chain reaction or enzyme-linked immunosorbent assay and immunostaining, respectively. In cultured rat gastric epithelial RGM1 cells, we examined effects of exogenous IGF-1 on cell migration, re-epithelialization, and proliferation-essential components of ulcer healing. We also examined whether IGF-1 induces cyclooxygenase (COX)-2 expression and determined the role of phosphatidylinositol 3-kinase and mitogen-activated protein kinase signaling pathways in mediating IGF-1 actions. Gastric ulceration triggered an approximately threefold increase in IGF-1 expression in epithelial cells of the ulcer margins (P < 0.001 versus control), especially in cells re-epithelizing granulation tissue and in mucosa in proximity to the ulcer margin. Treatment of RGM1 cells with IGF-1 caused a dramatic increase in actin polymerization, an eightfold increase in cell migration (P < 0.001), a 195% increase in cell proliferation (P < 0.05), and a sixfold increase in COX-2 expression (P < 0.01). Inhibitor of phosphatidylinositol 3-kinase abolished IGF-1-induced RGM1 cell migration and proliferation, actin polymerization, and COX-2 expression. The up-regulation of IGF-1 in gastric ulcer margin accelerates gastric ulcer healing by promoting cell re-epithelization, proliferation, and COX-2 expression via the phosphatidylinositol 3-kinase pathway.
Gretchen Long. 2012. Doctoring Freedom: The Politics of African American Medical Care in Slavery and Emancipation. The John Hope Franklin Series in African American History & Culture. Waldo E. Martin, Jr. and Patricia Sullivan, eds. Chapel Hill: University of North Carolina Press. $37.50. pp. 248. Cloth. ISBN: 978‐0‐8078‐3583‐8.

Review of Doctoring Freedom: The Politics of African American Medical Care in Slavery and Emancipation
Ethical Practice in the Accounting Publishing Process: Contrasting Opinions of Authors and Editors

Academic accounting researchers often offer anecdotal evidence that the publishing process is rife with unfair and unethical practices, and similar contradictory evidence supports accounting journal editors' claims that the process is fair and ethical. This study compares the perceptions of accounting authors and editors on the ethicacy and frequency of specific author, editor and reviewer practices. Both authors and editors are in general agreement about the ethical nature of editors and author practices. However, there are significant differences between the groups regarding reviewer behavior, and regarding the frequency of occurrence of questionable author, editor and reviewer practices. Additionally, the majority of authors believe that codes of publishing ethics are needed, while editors do not. Women authors are significantly more supportive of such ethical codes when compared to their male counterparts.
A PA for MBOFDM-UWB and IR-UWB transmitters

This paper describes the design of 4.2 to 5.9 GHz CMOS power amplifier (PA) for applications in ultra-wideband (UWB) commuincations. The PA operates in the linear region over the input range of −12 dBm and delivers an output power of 6 dBm. The post layout simulations indicate the power added efficiency (PAE) is more than 35% at 5 GHz frequency and more than 20% between 4.2 GHz and 5.9 GHz. The input matching is realized by resistive feedback and the output and the interstage matching are realized using source degeneration inductors. The input and output reflection coefficients are less than −5 dB over the frequency from 4.2 GHz to 5.9 GHz. The PA can also be used in IR UWB transmitters and provides energy efficiency of 11.3%. The total chip area is approximately 0.7mm2 including electrostatic discharge (ESD) protection. The design is implemented in 180nm CMOS technology.
Primed Facilitation of Homosynaptic Long-Term Depression and Depotentiation in Rat Hippocampus

Previous studies have demonstrated that prior synaptic activity can influence the subsequent induction of synaptic plasticity in the brain. Such temporal modulation of synaptic plasticity has been called “metaplasticity.” In this report, we describe the facilitatory effects of high-frequency stimulation on the induction of homosynaptic long-term depression (LTD) in the CA1 region of the rat hippocampus. The LTD induced by low-frequency stimulation (1 Hz) protocols was found to be homosynaptic and NMDA receptor-dependent. The facilitatory effects of the high-frequency stimulation-induced priming event itself were found to be NMDA receptor-independent and to have a duration of at least 90 min. The effects of priming also were heterosynaptic, because the induction of synaptic plasticity by low-frequency stimulation was enhanced at an unprimed synaptic pathway after the priming of an independent pathway. In addition to enhancing LTD, priming also enhanced the reversal of long-term potentiation elicited by a 5 Hz depotentiation protocol. Our results provide examples of how metaplasticity may play a key role in the ongoing modulation of the induction and stabilization of alterations in synaptic strength.
Recursive Query Answering with Non-Horn Clauses

In this paper, an algorithm is presented for answering recursive queries under the Generalized Closed World Assumption (GCWA) in a database with positive non-Horn ground clauses. It is proved that the algorithm generates all the answers under the GCWA. We consider only the transitive closure recursions in which only one base relation is involved. The set of ground clauses is stored as one relation so that a modified join operator can be applied to the clauses. The relation can be visualized as a directed graph with each tuple representing an edge. A query (only closed queries are considered in this paper) is answered by extracting the paths from the relation, forming the negative clauses from these paths, and sending the negative clauses together with the non-Horn clauses to a theorem prover. We proved that if the empty clause is derived then the answer to the query is true. This algorithm is efficient for two reasons: 1) facts (positive unit ground clauses) are processed by the modified join operator, and 2) the theorem prover handles only the non-Horn ground clauses and some negative ground clauses.
Migrating from 8- to 16-bit processors

During the mid 1990's, there has been a major upswing in the growth of applications requiring 16-bit microcontrollers. Dataquest have estimated that the growth of 16-bit devices will be more than double that of the combined growth of all categories of microcontrollers, at 43.9%. The main reasons for the growth in 16-bit applications is that pricing is becoming very competitive and traditional 8-bit applications typically require more processing power examples of these applications range from disk drive controllers, to airbags, to cellular communications. The trend for MCU users in embedded control systems is to migrate from assembly language to higher level languages such as C. The enhancement of instruction sets and addressing modes does not only make life easier for the assembly language programmer. When C code is compiled, the availability of lower-level resources such as efficient register use and data manipulation capabilities greatly increase the efficiency of the compiled C code. This is true for both code size generated and execution speed. Many of the enhancements of the M68HC12 have been a direct result of the recognition that M68HCll users need more performance and the option to migrate to a high level language without the penalties in code efficiency normally associated with such a step.
Large-scale dynamics in turbulent mixing and the three-dimensional space-time behaviour of outer fluid interfaces

Experiments have been conducted to investigate turbulent mixing and the dynamics of outer fluid interfaces, i.e. the interfaces between mixed fluid and pure ambient fluid. A novel six-foot-diameter octagonal-tank flow facility was developed to enable the optical imaging of fluid interfaces above the mixing transition, corresponding to fully developed turbulence. Approximately 10003 whole-field three-dimensional space– time measurements of the concentration field were recorded using laser-induced- fluorescence digital-imaging techniques in turbulent jets at a Reynolds number of Re ∼ 20 000, Schmidt number of Sc ∼ 2000, and downstream distance of ∼ 500 nozzle diameters. Multiple large-scale regions of spatially nearly uniform-concentration fluid are evident in instantaneous visualizations, in agreement with previous findings above the mixing transition. The ensemble-averaged probability density function of concentration is found to exhibit linear dependence over a wide range of concentration thresholds. This can be accounted for in terms of the dynamics of large-scale well- mixed regions. Visualization of the three-dimensional space–time concentration field indicates that molecular mixing of entrained pure ambient fluid is dynamically initiated and accomplished in the vicinity of the unsteady large scales. Examination of the outer interfaces shows that they are dynamically confined primarily near the instantaneous large-scale boundaries of the flow. This behaviour is quantified in terms of the probability density of the location of the outer interfaces relative to the flow centreline and the probability of pure ambient fluid as a function of distance from the centreline. The current measurements show that the dynamics of outer interfaces above the mixing transition is significantly different from the behaviour below the transition, where previous studies have shown that unmixed ambient fluid can extend across a wide range of transverse locations in the flow interior. The present observations of dynamical confinement of the outer interfaces to the unsteady large scales, and considerations of entrainment, suggest that the mechanism responsible for this behaviour must be the coupling of large-scale flow dynamics with the presence of small-scale structures internal to the large-scale structures, above the mixing transition. The dynamics and structure of the outer interfaces across the entire range of space–time scales are quantified in terms of a distribution of generalized level-crossing scales. The outer-interface behaviour determines the mixing efficiency of the flow, i.e. fraction of mixed fluid. The present findings indicate that the large-scale dynamics of the outer interfaces above the mixing transition provides the dominant contribution to the mixing efficiency. This suggests a new way to quantify the mixing efficiency of turbulent flows at high Reynolds numbers.
Revisiting the surgical creation of volume load by aorto-caval shunt in rats.

Cardiac hypertrophy is an early landmark during the clinical course of heart failure, and is an important risk factor for subsequent morbidity and mortality. The hypertrophy response to different types of cardiac overload is distinguished both at the molecular and cellular levels. These changes have been extensively characterized for pressure load hypertrophy; however, similar information for volume load hypertrophy is still needed. This study was undertaken to improve the existing method of producing experimental cardiac volume load. Previous investigators have employed surgical aorto-caval shunt (ACS) as a model for volume load hypertrophy (VO) in rats. The procedure is relatively simple and involves glue to seal the aortic hole after ACS. However, it has several limitations mostly related to the use of glue e.g. poor visualization due to hardening of tissues, imperfect sealing of the puncture site and glue seeping through the aortic hole resulting in shunt occlusion. We have modified the procedure using aortic adventitial suture instead of glue and 18G angiocatheter instead of 16G needle, which eliminated the technical difficulties from the former method. The ACS was visually confirmed at sacrifice, and the VO demonstrated by time-related changes in the heart weight/body weight ratio which increased from 78% at 4 weeks to 87% at 10 weeks and increased liver/body weight ratio by 22% at 10 weeks of post aorto-caval shunt. Cardiac expression of atrial natriuretic peptide (ANF) also demonstrated time-related increase in ANF mRNA (+275% increase at 4 weeks, p < 0.05, and +370% increase at 10 weeks, p < 0.001). This modified technique of aorto-caval shunt offers simpler, reproducible and consistent model for VO hypertrophy in rats.
Renormalization of configuration space into phase space (Can nonrealizable Hamiltonians be realized

We show that gauge-type coupling can be the basis for new renormalization phenomena in which ordinary configuration-space coordinates become effectively canonically conjugate. This is demonstrated first for the case of a particle in a very strong magnetic field, where some of the experimental consequences can be surprising. Another example is presented which suggests a possible new approach to the quark-confinement problem.
The interaction of the estrogen receptor with mononucleosomes.

Abstract To directly activate specific gene expression, the estrogen receptor (ER) must bind to estrogen receptor response elements (EREs) in the context of nucleosomes. In order to investigate the interaction of the ER with mononucleosomes, we developed a mononucleosome gel shift assay. A 164 bp high specific activity [ 32 P]probe DNA (32 bp consensus ERE with flanking regions separated by 23 nucleotides from an artificial nucleosome positioning sequence) was prepared. Nuclear extracts from MCF-7 cells or recombinant human ERα were incubated with the labeled ERE ± excess ERE. A retarded band was seen which was completely obliterated with excess ERE, confirming the specificity of binding. This probe was then used to make reconstituted mononucleosomes by sequential dilution of a high salt histone preparation. The nucleosomes were purified by sucrose density gradients and footprinting analysis was performed to demonstrate that the mononucleosomes were rotationally phased as seen by a periodic digestion pattern (10 bp) of the nucleosomes versus ERE. Nucleosomes were incubated with nuclear extracts containing ER or recombinant ERα. Dose dependence in the shift of the mononucleosomes with increasing concentrations of ER was observed. Specificity was demonstrated in experiments with excess ERE and anti-ER antibody. Footprinting analysis was also performed. We also determined that addition of high mobility group protein-2 (HMGB-2, a protein closely related to HMGB-1) with the ER increased the interaction of ER with mononucleosomes. These studies will allow us to address the interactions of ER with core histones containing a multiplicity of variants and modifications in nucleosomal structure.
Impact of increased external debt servicing on government budgetary priorities: The case of Argentina

Abstract As external debt servicing has increased, developing countries have been forced to re-evaluate programs in an effort to curtail government spending. This paper attempts to examine the character of the sectoral adjustments that have taken place (1961–1982) in the main functional areas of Argentinean government expenditures. In general, it appears that social services, particularly education and health along with public administration, have borne the brunt of the government's rising debt service problem. The social sectors have suffered further due to regime changes, with military regimes tending to cut back even more severely allocations to the social sectors than normal debt service constraints would have warranted.
Bernese periacetabular osteotomy for hip dysplasia in young adults.

ABSTRACT Hip dysplasia is one of the most common disorders of the hip, presenting in the first three years of life. Literature has shown that an association exists between developmental dysplasia of the hip and the development of secondary hip osteoarthritis in early adulthood. Treatment options are directed toward relieving symptoms and delaying or preventing the onset of arthritis in the affected hip. Total hip arthroplasty is a surgical option, but has been associated with a high rate of failure in younger, physically active patients. This article discusses the Bernese periacetabular osteotomy procedure as a treatment modality, which restores coverage of the femoral head with the acetabulum. Changing the anatomy allows the surgeon to increase the surface area of the femoral head that bears the patient's weight. Increasing the weight-bearing surface may prevent further damage to the hip's cartilage and delay the onset of osteoarthritis. AORN J 75 (April 2002) 737-751.
Language as a Tool in Diverse Forms of Learning.

Abstract In this manuscript we report on a curriculum design project in which we worked with students in an urban immigrant community to study their own language practices in different contexts. We gathered videotaped data of students in the classroom as well as videos they took of their language practices in other settings. We focus on one student's engagement in this project, and ask how he uses language as a communicative tool in two different activity settings: filling out a form at home with his father, and filling out a form at school. We illuminate variations in this boy's use of language as a communicative and meaning-making tool across these activity settings, finding that he drew on a broader set of communicative tools in interactions with his father at home, including multi-modal communicative strategies, than he did in a similar activity in school. We use these data to complexify discussions of continuities and discontinuities in everyday and school language practices. We conclude with suggestions for how schools can support students’ use of language as a tool for thinking and acting in diverse contexts.
A graphic method of routing floods through reservoirs

Recent floods have brought the people of this nation to view the problem of flood-control with increased interest. To effect the desired control, it is axiomatic that the runoff-rates must be reduced. This may be accomplished through two major approaches which may supplement the existing capacity in a watershed for (1) infiltration or absorption of rainfall into the soil-cover and profile, when possible, and (2) detention and desynchronization of flood wave-crests by the use of surface-storage. This paper deals with the latter phase limited to a method of routing floods through the surface-storage of reservoirs.
NEGLIGIBLE GLUCONEOGENESIS BY THE FETAL LAMB LIVER

Previous studies of gluconeogenic capability of the fetus in vivo have yielded conflicting results, and the specific role of the fetal liver in gluconeogenesis has not been defined. We studied 7 fetal lambs with mean gestational age 130.5 days (range 122-140d). We placed catheters in maternal artery and vein and in fetal hindlimb artery (FA) + vein (IVC), right or left hepatic vein (RHV, LHV), and umbilical vein (UV). After 3-5 days recovery, 14C-alanine (25 μCi bolus, 20 μCi/hr continuous infusion) or 14C-lactate (40 μCi bolus, 30 μCi/hr continuous infusion) was infused into fetal IVC. Lactate and glucose concentrations, glucose specific activity, and substrate radioactivity were measured after 30 and 60 minutes. Radioactive microspheres were injected into UV to measure liver blood flow. 14C-Glucose uptake and release by the liver was calculated; net labelled glucose was calculated as a percentage of 14C-substrate perfusing the liver. Mean glucose uptake from the placenta was 6.00 mg/kg/min (range 2.13-16.0). Glucose uptake or release by each liver lobe was only 0.70 mg/min; (range -3.7 to 9.5). Only 0.35% (range 0-2.3%) of 14C-substrate was converted to 14C-glucose; 14C-lactate (0.29%) and 14C-alanine (0.38%) were not significantly different. There was a suggestion that the left lobe converted less substrate to glucose (0.03%) than did the right (0.48%). We conclude that hepatic gluconeogenesis contributes negligibly to fetal glucose supply. Warnes et al. showed gluconeogenesis is present within minutes after birth. Our model permits the evaluation, in utero, of mechanisms that stimulate gluconeogenesis.
Dorvilleidae (Annelida:Polychaeta) from the U.S. Atlantic slope and rise. Description of two new genera and 14 new species, with a generic revision of Ophryotrocha

The present paper contains descriptions of 14 new species of dorvilleid polychaetes that are part of a highly diverse benthic infauna sampled on the U.S. Atlantic slope and rise between the Canadian border and South Carolina. Quantitative samples were taken with a Hessler-Sandia box core during 18 cruises between 1983 and 1987. Samples were sieved through screens having a mesh opening of 300 μ. The newly described species belong to the genera Ophryorrocha. Exallopus. Parophryotrocha and two new genera, Pseudophryotrocha gen.n. and Anchidorvillea gen.n. An emended generic diagnosis of Ophryotrocha is provided to accommodate some of the new species, but also to include a group of atypical species described earlier by several authors who had modified the generic concept of Ophryotrocha without providing a formal emendation. The genus Ophryotrocha is revised to contain 31 species helonging to two species groups. A comparison of a suite of morphologic characters, however. indicates that these species addressed in this paper are discussed in the context of the entire family Dorvilleidae.
The impact of the changing fatty acid profile of fats on diet assessment and health

We are transiting a time in which advances in plant molecular biology and genetics have resulted in a remarkable array of oils and fats that have a modified fatty acid profile, compared to the parent stock variety. The rapid evolution of modified oils and fats poses challenges for keeping nutrient databases current as well as deciphering what new fats/oils are used, from the standpoint of diet assessment and, in particular, collecting accurate dietary data. The expanding array of modified fats and oils has been designed to have greater shelf stability due to an increase in monounsaturated fat and enhanced health benefits due to a reduction in trans fat. The effects of oilseeds reduced in alpha-linolenic acid (ALA) on health outcomes need to be evaluated since diets rich in ALA have many health benefits.
The role of testosterone in the displays of some ducks

1. 1. Downy male Pintail ducklings were induced to give adult courtship displays by daily injections of testosterone. No typically female displays were seen. 2. 2. Downy Redhead males frequently gave Head-throws and Courting notes after testosterone injections, but females were not observed to give displays. 3. 3. Despite continued treatment, the Redheads gradually ceased giving displays. 4. 4. Downy male Mallard ducklings were induced to give displays by testosterone injections; females gave pre-copulatory Head-pumping, a display typical of adults of both sexes. 5. 5. Castrated adult male Mallards gave all the courtship displays when injected with testosterone, but castrates without hormone injections gave only occasional pre-copulatory Head-pumps. 6. 6. The absence of stimuli from courting females is suggested as the cause for the rarity of many displays in injected ducklings.
Association of Sleep Duration with Obesity among US High School Students

Increasing attention is being focused on sleep duration as a potential modifiable risk factor associated with obesity in children and adolescents. We analyzed data from the national Youth Risk Behavior Survey to describe the association of obesity (self-report BMI ≥95th percentile) with self-reported sleep duration on an average school night, among a representative sample of US high school students. Using logistic regression to control for demographic and behavioral confounders, among female students, compared to 7 hours of sleep, both shortened (≤4 hours of sleep; adjusted odds ratio (95% confidence interval), AOR = 1.50 (1.05–2.15)) and prolonged (≥9 hours of sleep; AOR = 1.54 (1.13–2.10)) sleep durations were associated with increased likelihood of obesity. Among male students, there was no significant association between obesity and sleep duration. Better understanding of factors underlying the association between sleep duration and obesity is needed before recommending alteration of sleep time as a means of addressing the obesity epidemic among adolescents.
Phosphatase in Human Saliva: Its Relationship to Calculus and Lactobacillus Counts

BOTH the origin and function of phosphatase in saliva are still in question. Several sources for this enzyme, including desquamated epithelial cells,' gingival tissue,2' and microorganisms of the saliva,-5 have been postulated, the latter being the most probable. Adamson' and Smith2 were among the first to propose that phosphatase, which is capable of liberating inorganic phosphate from organic phosphate may play a role in the formation of calculus. Glock, Murray, and Pincus4 and Ennever and Warner9 found that the organisms most commonly associated with calculus, namely, Actinomyces, show marked phosphatase activity. Tenenbaum and Karshan,0 showed that, in general, people with calculus have higher Ca and P levels in the saliva, and hence they hold tenable the theory that phosphatase plays a role in calculus formation. Saltzmann," on the other hand, using a limited number of patients (fourteen), found that the degree of phosphatase in saliva was not related to the presence and quantity of calculus in the mouth. The relation of phosphatase to caries activity has also been studied. Lactobacilli, generally associated with the caries process, have been found to possess some phosphatase activity, although of a very low order.7' 8, 12 Rae'3 reported no apparent relationship between the phosphatase content of saliva and the susceptibility to caries in thirty-nine boys; however, Fitzgerald,8 in an initial trial with thirty cases, claimed to have obtained generally parallel results between acid phosphatase activity and lactobacillus counts, and he suggested further study of acid phosphatase activity of saliva as an additional laboratory test for caries activity. The purpose of this investigation was to study simultaneously the relationship of phosphatase levels to the presence of calculus and Lactobacillus counts in the same individuals.
Muon Beam Polarization at the LAMPF Biomedical Channel

Recent modifications to the LAMPF Biomedical Channel1 have improved versatility for stopping pion and muon physics experiments. High muon polarization was achieved by favorable kinematic selection of the decay muons. This polarization has been measured and found to be close to the design expectation of about 85%. The Hanle method2 was employed to measure the polarization by observing left-right decay asymmetry at right angles to the beam with small precession fields (0-50 gauss). This technique is particularly suitable for high-intensity muon beams.
An electron tube for viewing magnetic fields

Magnetic field patterns may be “seen” through the use of specially constructed gaseous diodes which produce luminous ionized beams that follow the direction of the flux paths.
Design of hydrodynamically confined microfluidics: controlling flow envelope and pressure

Closed-channel microfluidic devices are widely used in a number of chemical and biological applications; however, it is often difficult to interact with samples, such as cells, that are enclosed inside them. Hydrodynamically confined microflows (HCMs) allow microfluidic-type flows to be generated in open liquid environments, such as Petri dishes, thus greatly increasing the flexibility of microfluidic approaches. HCMs have previously been used for protein patterning and selective cell treatment applications, but the underlying fluid mechanics is not fully understood. Here, we examine the effect of device geometry and flow parameters on the properties of the flow envelope and pressure drop of several two-port HCM devices using a combination of experiments and modeling. A three-port device, which allows for different flow envelope shapes to be generated, is also analyzed. The experimental results agree well with the 3-D computational fluid dynamics simulations, with the majority of the measurements within 10% of the simulations. The results presented provide a framework for understanding the fluid mechanics of HCMs and will aid in the design of HCM devices for a broad range of applications.
The echinoid mitotic gradient: Effect of cell size on the micromere cleavage cycle

Like other euechinoids, the fertilized eggs of the sand dollar Dendraster excentricus proceed through cleavages that produce a pattern of macromeres, mesomeres, and micromeres at the 4th division. The 8 cells of the macro-mesomere lineage proceed through 6 additional cleavages before hatching. At the fifth overall division, the 4 micromeres produce a lineage of large micromeres that will divide 3 additional times, and a lineage of small micromeres that will divide once more before hatching. Irrespective of lineage, the length of the cell cycles is closely related to the size of the blastomere; cells of the same size have the same cell cycle time. A consequence is that at the fourth cleavage, there is a gradient of mitotic activity from the fastest dividers at the animal pole and the slowest cleaving micromeres at the vegetal pole. By the time of hatching, which is the 10th division of meso-macromeres, all cells are the same small size, the metachronic pattern of division gives way to asynchrony, and the mitotic gradient along the polar axis is lost. Experimental pre-exposure to sodium dodecyl sulfate (SDS), however, blocks the appearance of the gradients in cell size, the mitotic gradient, and the differential in cell cycle times. It is proposed that the mitotic gradients, cell cycle times, and attainment of a state of asynchrony are functions of cell size. Developmental consequences of the transition are large, and include coordinated activation of transcriptions, synthesis of new patterns of proteins, alterations of metabolism, and onset of morphogenesis. Mol. Reprod. Dev. 78:868–878, 2011. © 2011 Wiley Periodicals, Inc.