cssi/SciSciGPT-SciSciNet huggingface dataset:
Epiphyte and herbivore interactions impact recruitment in a marine subtidal system

Marine assemblages are influenced by the rate and timing of species settlement and recruitment. Both abiotic factors and biotic interactions can impact recruitment rates of marine species in a variety of systems. However, the impacts of species which recruit at the same time upon each other are less well understood. We investigated the relationship between the recruitment of Lacuna vincta, a small (<6 mm shell diameter) marine snail, and two species of algal epiphytes, the native Ceramium virgatum and the invasive Neosiphonia harveyi, in the shallow subtidal zone of Narragansett Bay, Rhode Island. All three species exhibit peak recruitment densities during two months in the summer. We found that the presence of algal epiphytes facilitates the recruitment rate of L. vincta, regardless of the epiphyte species composition. We also found a positive relationship between the number of L. vincta present and epiphyte recruitment, which is disproportionately driven by higher recruitment of N. harveyi than C. virgatum. Understanding recruitment dynamics and interactions is vital to effectively mitigate the effects of and adaptations to changes due to the establishment of non-native species.
Preparation of automobile organic emission surrogates for photochemical model validation

Abstract Irradiation chamber studies of the photochemistry of motor vehicle emissions generally use relatively simple surrogates (often fewer than 30 compounds) of complex emissions (often greater than 250 compounds). The question is often asked: Can the photochemistry of complex organic mixtures be adequately simulated by chamber studies using simple surrogate mixtures? The complexity of the compositional profile of motor vehicle organic emissions results in large part from the complexity of the fuel (i.e., the combustion derived compounds are relatively small in number). An experimental protocol is described by permitting preparation of representative complex (greater than 250 compounds) emission surrogates adding a small number (fewer than 30) of selected compounds to the vehicle fuel. Irradiation chamber runs of actual motor vehicle exhaust samples are contrasted with similar runs of associated complex mixture emission surrogates demonstrating the accuracy with which the exhaust photochemistry can be simulated using the surrogate. Time-resolved profiles of NO, NO x –NO, and ozone concentrations, and selected 12.5 h product concentrations, are presented as examples of the comparability of the exhaust and surrogate photochemistry. The observed exhaust and surrogate concentration profiles product distributions are very similar.
Transfusion associated microchimerism: a heretofore little-recognized complication following transfusion.

Potent antiplatelet and antithrombotic agents have significantly reduced mortality in the setting of acute coronary syndromes and percutaneous coronary intervention. However these agents are associated with increased bleeding which is in turn associated with adverse clinical outcomes. In many centers, transfusion is often used to correct for blood loss. Blood transfusion in the setting of acute coronary syndrome has been associated with adverse clinical outcomes including increased mortality. Transfusion associated microchimerism (TA-MC) is a newly recognized complication of blood transfusion. There is engraftment of the donor’s hematopoietic stem cells in patients who then develop microchimerism. This article discusses the association of bleeding/blood transfusion with adverse outcomes and the potential role of TA-MC in clinical outcomes.
Prenatal growth in the cynomolgus and rhesus macaque (Macaca fascicularis and Macaca mulatta): A comparison by ultrasonography.

The rhesus monkey has played an important role in the history of reproductive research. Because of limitations on the exportation and availability of this species, several other species of nonhuman primates have been considered as alternate models. Among them is the crab-eating, or cynomolgus, macaque (Macaca fascicularis), which displays similarities in developmental, reproductive, and physiological parameters. The use of both species of macaques for pregnancy-related studies necessitates the assessment of differences in growth and development through gestation. Observations during the embryonic and fetal periods in both species have been compared with diagnostic ultrasound. Results indicate no significant differences in size during the embryonic and early fetal periods, but a greater acceleration of growth in the rhesus begins at approximately 100–110 gestational days (GD). Analysis of embryonic and fetal heart rates indicate no differences between the two species. Normal predictive values for a variety of growth parameters including gestational sac, greatest length, biparietal diameter, and femur length have boon calculated by multiple regression analysis. These charts have proven useful for confirming the gestational age after timed matings and for predicting the age of animals for which the conception date is not known.
Interface-disrupting amino acids establish specificity between T cell receptors and complexes of major histocompatibility complex and peptide.

Interface-disrupting amino acids establish specificity between T cell receptors and complexes of major histocompatibility complex and peptide
Photodissociation of magnesium ion/molecule complexes in a reflectron time-of-flight mass spectrometer

Abstract Ion/molecule cluster complexes containing magnesium (e.g., Mg + −(CO 2 ) x , Mg + −(H s O) x ) are generated in a pulsed nozzle cluster source. Specific ions are size selected from the source distribution with a reflectron time-of-flight mass spectrometer for studies of their photodissociation dynamics. Photoexcitation of these complexes near the Mg + ( 2 S→ 2 P) resonance line causes a variety of novel photochemistry, ranging from simple ligand ejection, to metal insertion, to metal-ligand charge exchange. These reactions are first observed in the single molecule complexes, and they persist in larger aggregates with more extensive solvation. Excitation spectra probe the energy dependence of the photochemistry and they provide information on the structures of the ion/molecule complexes.
High-Risk Feedback: A Brief Intervention to Increase Motivation to Change Anxiety

Elevated levels of anxiety sensitivity (AS), the fear of anxiety and its consequences, places individuals at an increased risk for the development of anxiety disorders, especially panic disorder. Research has shown that treating AS may reduce the future development of anxiety psychopathology. However, individuals high in AS may be unaware of the risks associated with this risk factor and, therefore, may tend to be unaware or unmotivated to change AS. The purpose of the current study was to investigate the effect of providing high-risk feedback in those at-risk for developing anxiety psychopathology. Participants consisted of 55 non-treatment seeking individuals with clinically significant levels of AS. Participants completed a battery of baseline questionnaires, received high-risk feedback about their level of anxiety sensitivity, and completed post-study questionnaires. Results revealed significant increases in motivation. Specifically, there were significant increases in the importance and confidence to change anxiety after receiving the high-risk feedback. Implications of the findings and future directions are discussed.
Importance of Nonlinear Anisotropic Modeling of Granular Base for Predicting Maximum Viscoelastic Pavement Responses under Moving Vehicular Loading

AbstractThis paper explains the importance of using a nonlinear anisotropic three-dimensional (3D) finite-element (FE) pavement model to simulate the granular base layer and predict viscoelastic pavement responses under moving vehicular loading. The FE model was built using the general-purpose FE software ABAQUS, and a user material subroutine was developed to implement the constitutive model of granular material using a modified Newton-Raphson approach with secant stiffness. The FE model utilizes implicit dynamic analysis and simulates the vehicular loading as a moving load with 3D contact stresses at the tire-pavement interface. The analysis results indicate that it is important to consider the viscoelastic nature of the asphalt layer and the moving load for accurately capturing the nonlinear granular base modulus in the mechanistic pavement model. The modulus distribution in the granular base layer is affected not only by wheel load and pavement structure (such as asphalt layer thickness and subgrade s...
Optimizing stem cell transplantation in myelodysplastic syndromes: unresolved questions.

Purpose of reviewAllogeneic hematopoietic stem cell transplantation (HCT) is the only curative therapy for myelodysplastic syndrome (MDS). Recent efforts to optimize the curative potential of transplant have focused on pretransplant therapy options, the use of predictive models to improve patient se
Effect of natural antioxidants in virgin olive oil on oxidative stability of refined, bleached, and deodorized olive oil

The factors influencing the oxidative stability of different commercial olive oils were evaluated. Comparisons were made of (i) the oxidative stability of commercial olive oils with that of a refined, bleached, and deodorized (RBD) olive oil, and (ii) the antioxidant activity of a mixture of phenolic compounds extracted from virgin olive oil with that of pure compounds andα-tocopherol added to RBD olive oil. The progress of oxidation at 60°C was followed by measuring both the formation (peroxide value, PV) and the decomposition (hexanal and volatiles) of hydroperoxides. The trends in antioxidant activity were different according to whether PV or hexanal were measured. Although the virgin olive oils contained higher levels of phenolic compounds than did the refined and RBD oils, their oxidative stability was significantly decreased by their high initial PV. Phenolic compounds extracted from virgin olive oils increased the oxidative stability of RBD olive oil. On the basis of PV, the phenol extract had the best antioxidant activity at 50 ppm, as gallic acid equivalents, but on the basis of hexanal formation, better antioxidant activity was observed at 100 and 200 ppm.α-Tocopherol behaved as a prooxidant at high concentrations (>250 ppm) on the basis of PV, but was more effective than the other antioxidants in inhibiting hexanal formation in RBD olive oil.o-Diphenols (caffeic acid) and, to a lesser extent, substitutedo-diphenols (ferulic and vanillic acids), showed better antioxidant activity than monophenols (p- ando-coumaric), based on both PV and hexanal formation. This study emphasizes the need to measure at least two oxidation parameters to better evaluate antioxidants and the oxidative stability of olive oils. The antioxidant effectiveness of phenolic compounds in virgin olive oils can be significantly diminished in oils if their initial PV are too high.
Assembly-dependent phosphorylation of myosin and paramyosin of native thick filaments in Caenorhabdiris elegans

Summary Phosphorylation of the thick filament proteins myosin and paramyosin was studied in Caenorhabditis elegans . We have incubated partially purified, native thick filaments with [γ 32 P] ATP in the presence of 50–750 mM NaCl, pH 6.5–8.0. Myosin heavy chain and paramyosin were phosphorylatable only upon solubilisation at 450 mM and higher NaCl concentrations. Under conditions preserving native structures, no phosphorylation of these proteins occurred. The phosphorylation required Mg 2+ but was unaffected by cAMP, cGMP or Ca 2+ . The specific inhibitor of cAMP and cGMP kinase catalytic subunits, H8, inhibits the activity. Sedimentation experiments show that the kinase may associate with but is not an intrinsic component of thick filaments. In C. elegans , phosphorylation by the thick filament associated activity of myosin and paramyosin is dependent upon the state of their assembly.
Activin Receptors and Cellular Signaling by the Receptor Serine Kinase Family

AN EMERGING theme in cell signaling research is the multifunctional nature of many growth factors and cytokines. Proteins purified based on distinct activities are often found to have identical structures; furthermore, different members of large growth factor families have similar, although subtly distinct, effects on diverse sets of cells. Such related factors often have related receptors, activation of which turns on common cellular signaling pathways. Understanding both the specificity and the overlap of growth factor signaling will involve elucidation of the unique and shared features of those receptors and their intracellular targets. The activins are growth and differentiation factors that are produced by, and exert effects on, a broad range of cells and tissues (reviewed in Refs. 1–5). With the cloning of several activin receptors, as well as the development of biological models for assessing activin and activin receptor function, substantial progress has been made in understanding the mechanism of...
The Lecompton Constitution

Ellis discusses this pre-Civil War pro-slavery constitution of Kansas.Â For two generations the Lecompton Constitution lay hidden from the public eye in a Rutgers safe.
Growth assessment in abnormal children

The purpose of growth assessments in children with abnormal growth is to determine the status of their present size and development, to monitor their progress by serial assessments, and, when possible, to predict their adult stature. Growth assessments also provide the means by which the effects of disease and its treatment upon growth can be evaluated. For these purposes statistical treatment of the data are required. The assessment of physical growth is primarily concerned with statural growth. Weight gain and changes in body composition, however, are other useful indices of growth itself; these also correlate with statural growth. Skeletal and sexual maturation are important developmental landmarks which are used to predict adult stature. This report describes the measurements commonly used in growth assessments, how the measurements are made and expressed, and how they might be treated for serial and for statistical purposes. Other recent articles provide this information in greater detail [1, 2].
Analysis of channel and disk subsystems in computer systems

The information processing industry has shifted from the conventional mathematical computation to information management. Interactive use of a system with large data bases is now widespread, and the data base has become one of the key factors central to an overall system design. This, in turn, has prompted the development of new peripheral devices.
Mining medical claims data with exploratory to confirmatory statistical methods

Medical billing errors constitute a major problem in the medical payment system in the USA. Little is known about how to identify the predictors that influence the error rate in hospital billings. Health services researchers have concentrated to a large extent on applying exploratory statistical methods to identify the patterns of care and analyse the variation in health services use. Despite the importance of medical claims data for detecting billing errors or fraudulent billing practises, little is known about the extent to which variations in the frequency, types, and seriousness of deficiencies reflect differences in the quality of care or broad systemic differences in the provision and use of health services. To address that gap, we propose an evidence-based approach to mining claims data to not only identify patterns of care, but also examine how individual, organisational and contextual factors may influence a particular pattern of Medicare/Medicaid fraud or abuse.
Strain distribution patterns for genetic markers in the LSXSS recombinant-inbred series

We present the strain distribution patterns (SDPs) of 118 SSLP markers and three pigmentation genes that have been characterized in 27 strains from the LSXSS RI series. This coarse map provides a resource for linkage studies of phenotypes that are heritable in the LSXSS RI series. The LSXSS recombinant inbred (RI) strains were derived from the Long-Sleep (LS) and Short-Sleep (SS) selected lines of mice that were selected for differential sensitivity to ethanol but are also differentially sensitive to a variety of other alcohols, barbiturates, sedative hypnotics, and general anesthetics. Since the parents were not inbred, two atypical factors are present in these SDPs. First, more than two alleles are frequently found in these RIs, and second, some alleles can be uniquely associated with one or the other parent while other alleles may be found in both parental lines. To validate the markers found in the parental line, we genotyped all parental mice from one generation of both the LS and SS lines, thus leading to a set of marker SDPs that are useful for further phenotypic association and identification of provisional QTLs.
The epidemiology of common fears and phobia

Abstract Incidence and prevalence data for common fears and phobia based on a probability sample of the general population show the frequency of mild phobia to be 76:9/1000 and of severe phobia to be 2.2/1000. Clinical samples are not representative of the distribution of phobia in the general population, agoraphobia being over-represented. The most frequent reason for consulting a physician is for him to minimize a severe fear or phobia of a medical procedure. Psychiatrists tend to see only the more severe phobics, although only a quarter of this group were found to be in treatment.
Electrostatically Self-Assembled Nanocomposite Reactive Microspheres

Nanocomposite reactive microspheres with diameters of ∼1−5 μm were created via electrostatic self-assembly of aluminum and cupric oxide nanoparticles. The ability to utilize this novel approach of bottom-up assembly to create these reactive materials allows for the potential for a more intimate mixture between the two nanoreactants and, thus, an overall more energetic combustion process. Experiments with the self-assembled material demonstrate the ability to achieve ignition and sustain a combustion wave in rectangular microchannels, which does not occur with material having similar amounts of organics mixed via the traditional sonication method.
Building long-term orientation in buyer–supplier relationships: The moderating role of culture

Abstract This research investigates buyer–supplier relationships in international markets. Research and practice have shown that buyer–supplier relationships benefit when partners to the relationship exhibit a long-term orientation. The extant literature suggests that a buyer's trust of a supplier and the supplier's performance affect the buyer's long-term orientation toward the relationship. We propose that the relative effects of trust and performance on long-term orientation are moderated by culture – specifically the individualism/collectivism dimension. Hypotheses are tested on data from two individualist and two collectivist cultures, using responses from over 600 purchasing professionals in the United States, Anglophone Canada, Francophone Canada and Mexico. Taken together, empirical findings suggest that cultural differences warrant consideration in developing successful purchasing strategies.
A comparison of type III solar radio burst theories using satellite radio observations and particle measurements.

The required electron density to excite a type III solar burst can be predicted from different theories, using the low frequency radio observations of the RAE-1 satellite. Electron flux measurements by satellite in the vicinity of 1 AU then give an independent means of comparing these predicted exciter electron densities to the measured density. On this basis, one theory predicts the electron density in closest agreement with the measured values.
The geographic concentration of economic activity across the eastern United States, 1820–2010

Abstract The historical dynamics of the geographic distribution of economic activity across the eastern United States between 1820 and 2010 are examined using the smallest feasible geographic entities, counties, as units of analysis. The region first experienced increasing spatial concentration of population and manufacturing, with inequality peaking early in the twentieth century. Population and manufacturing have since become more dispersed. Agriculture showed the opposite pattern: initial dispersion followed by increasing concentration. Initially, counties with a high manufacturing density also had a high agricultural density. Eventually, agricultural production moved to outlying areas while manufacturing remained concentrated near where it originated.
DNA‐replication Fidelity, Mismatch Repair and Genome Instability in Cancer Cells

It has been suggested that an early event in the multistep progression of a normal cell to a tumor cell could be a defect that leads to an elevated mutation rate, thus providing a pool of mutants upon which selection could act to yield a tumor. Such a mutator phenotype could result from a defect in any of several DNA transactions, including those that determine the DNA replication error rate or the ability to correct replication errors. Recent evidence for the latter is the mutator phenotype observed in tumor cells of patients having a hereditary form of colon cancer. These patients have a germline mutation in genes required for post-replication DNA mismatch repair. A second mutation arises somatically, yielding a greatly elevated mutation rate due to an inability to correct DNA replication errors. This connection between cancer, DNA replication errors and defective mismatch repair is the subject of this review, wherein we consider the key steps and principles for high fidelity replication and how their perturbation results in genome instability.
Uncertainty of the Assumptions Required for Estimating the Regulatory Flood: Red River of the North

AbstractFederal guidelines specify the log-Pearson Type III (LP3) distribution as the basis for the estimation of the 100-year peak discharge that serves as the regulatory flood for floodplain management in the United States. The LP3 distribution has been shown to provide a reasonable and flexible model of flood risk. Use of the LP3 distribution involves a number of explicit assumptions about the annual maximum series that are often implicitly assumed but not shown directly to be satisfied in flood frequency analysis studies of individual stations. In this case study, the validity of these assumptions for the Red River of the North at Grand Forks gaging station is examined. None of the four examined assumptions are satisfied completely. The stationarity assumption is not met because the regional climate samples two separate climatic modes, the peak discharge time series is not a random and independent set of events, the precipitation—runoff relationships are not uniform over time, and the flood peaks resu...
Enhanced albumin protein separations and protein—drug binding constant measurements using anti-inflammatory drugs as run buffer additives in affinity capillary electrophoresis

An affinity capillary electrophoresis (ACE) method for improving albumin protein separations has been developed. Separation efficiencies for bovine serum albumin (BSA) and human serum albumin (HSA) are dramatically improved by using anti-inflammatory compounds as run buffer additives. The anti-inflammatory drugs used as biospecific ligands to improve the protein separation include ibuprofen (IB), flurbiprofen (FL), and ketoprofen (KE). The binding constants of proteins (BSA and HSA) for the anti-inflammatory ligands (FL and IB) are estimated by ACE and compared to literature values.
Nonuniformity in the linear network model of the oculomotor integrator produces approximately fractional-order dynamics and more realistic neuron behavior

The oculomotor integrator is a network that is composed of neurons in the medial vestibular nuclei and nuclei prepositus hypoglossi in the brainstem. Those neurons act approximately as fractional integrators of various orders, converting eye velocity commands into signals that are intermediate between velocity and position. The oculomotor integrator has been modeled as a network of linear neural elements, the time constants of which are lengthened by positive feedback through reciprocal inhibition. In this model, in which each neuron reciprocally inhibits its neighbors with the same Gaussian profile, all model neurons behave as identical, first-order, low-pass filters with dynamics that do not match the variable, approximately fractional-order dynamics of the neurons that compose the actual oculomotor integrator. Fractional-order integrators can be approximated by weighted sums of first-order, low-pass filters with diverse, broadly distributed time constants. Dynamic systems analysis reveals that the model integrator indeed has many broadly distributed time constants. However, only one time constant is expressed in the model due to the uniformity of its network connections. If the model network is made nonuniform by removing the reciprocal connections to and from a small number of neurons, then many more time constants are expressed. The dynamics of the neurons in the nonuniform network model are variable, approximately fractional-order, and resemble those of the neurons that compose the actual oculomotor integrator. Completely removing the connections to and from a neuron is equivalent to eliminating it, an operation done previously to demonstrate the robustness of the integrator network model. Ironically, the resulting nonuniform network model, previously supposed to represent a pathological integrator, may in fact represent a healthy integrator containing neurons with realistically variable, approximately fractional-order dynamics.
Artificial intelligence for pattern recognition in automated surface engineering

Ability to measure the surface quality in real-time has many applications in manufacturing automation and product optimization, especially in processes in which the surface qualities such as roughness, grain size, thickness of coding, impurities size and distribution, hardness, and other mechanical properties are of importance. Surface analysis in manufacturing environments requires specialized filtering techniques. Due to the immense effect of rough environment and corruptive parameters, it is often impossible to evaluate the quality of a surface that has undergone various grades of processing. The algorithm presented here is capable of performing this comparison analytically and quantitatively at a low computational cost (real-time) and high efficiency. The parameters used for comparison are the degree of blurriness and the amount of various types of noise associated with the surface image. Based on a heuristic analysis of these parameters the algorithm assesses the surface image and quantifies the quality of the image by characterizing important aspects of human visual quality. Extensive effort has been set forth to obtain real-world noise and blur conditions so that the various test cases presented here could justify the validity of this approach well. The tests performed on the database of images produced valid results for the proposed algorithm consistently. This research aims at providing image processing tools for comparison and assessment of a surface processed under different grades of a manufacturing process all the way up to optimal processing. This paper presents the description and validation (along with test results) of the proposed algorithm for surface image quality assessment.
Structure and Biochemical Characterization of Protein Acetyltransferase from Sulfolobus solfataricus

The Sulfolobus solfataricus protein acetyltransferase (PAT) acetylates ALBA, an abundant nonspecific DNA-binding protein, on Lys(16) to reduce its DNA affinity, and the Sir2 deacetylase reverses the modification to cause transcriptional repression. This represents a "primitive" model for chromatin regulation analogous to histone modification in eukaryotes. We report the 1.84-A crystal structure of PAT in complex with coenzyme A. The structure reveals homology to both prokaryotic GNAT acetyltransferases and eukaryotic histone acetyltransferases (HATs), with an additional "bent helix" proximal to the substrate binding site that might play an autoregulatory function. Investigation of active site mutants suggests that PAT does not use a single general base or acid residue for substrate deprotonation and product reprotonation, respectively, and that a diffusional step, such as substrate binding, may be rate-limiting. The catalytic efficiency of PAT toward ALBA is low relative to other acetyltransferases, suggesting that there may be better, unidentified substrates for PAT. The structural similarity of PAT to eukaryotic HATs combined with its conserved role in chromatin regulation suggests that PAT is evolutionarily related to the eukaryotic HATs.
Characteristic Length Scale of Nanorod Diameter during Growth

This Letter proposes a characteristic length scale on surfaces and demonstrates its impact on nanorod growth. The proposed length scale is the dimension of a surface segment bounded by multiple-layer steps. Lattice kinetic Monte Carlo simulations, taking Cu as the prototype of nanorods, show that the proposed length scale (i) exists as the result of a diffusion barrier of adatoms down multiple-layer steps, (ii) dictates that the diameter of metallic nanorods is on the order of several hundred nanometers, and (iii) sets the upper limit of the facet dimension.
High Molecular Weight Ribonucleic Acids from the Nuclei of Calf Thymus

A RIBONUCLEIC acid fraction, which gives the characteristic sedimentation pattern shown in Fig. 1, has been isolated very recently from tobacco leaves1, mouse brain2 and microsomes of rat liver1. The molecular weights of components A and B are 1.7 × 106 and 0.6 × 106, respectively. Although the study has yet to be extended to other systems, I suggested two years ago that ribonucleic acids with molecular weights of about 1.7 × 106 exist in the cytoplasm of many types of cells3. The question that naturally arises is whether ribonucleic acids of such a molecular weight also exist in a nucleus. So far no investigation along this line has been reported. The results presented below appear to provide an answer to the question.
Data association for track initiation and extension using multiscan windows

The central problem in multitarget-multisensor tracking is the data association problem of partitioning the observations into tracks and false alarms so that an accurate estimate of the true tracks can be recovered. Many previous and current methodologies are based on single scan processing, which is real-time, but often leads to a large number of partial and incorrect assignments, and thus incorrect track identification. The fundamental difficulty with this approach is that there is simply not enough information in single scan processing to properly partition the observations into tracks and false alarms. In this work we formulate the problem of data association for track initiation and extension using multiscan windows in order to obtain superior track identification. A model problem is investigated to show the effect of window size, probability of detection, probability of false alarms, and measurement error on solution quality and timings.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Stream of Overflows from a Finite Queue

A finite queuing system with a recurrent arrival process and a single negative exponential server is considered. A customer who, upon his arrival, finds the system full departs never to return, i.e., he "overflows." The process of overflows is shown to be a recurrent process and the distribution of the time between overflows is derived as a recurrence time distribution in a semi-Markov process. In the special case where the maximum number of customers allowed in the system is one, the problem is known as Palm's overflow problem.
Vorticity generation in the shallow-water equations as applied to hydraulic jumps

Abstract The authors attempt to find a bridge between the vorticity dynamics of a finite cross-stream length hydraulic jump implied by the Navier-Stokes equations and that given by the shallow-water approximation (SWA) with the turbulence of the hydraulic jump parameterized. It is established that, in the actual hydraulic jump, there is horizontal vorticity associated with the time-mean flow in the fluid interior, and that this vorticity has been fluxed down by turbulent eddies from the upper part of the fluid layer. The authors then point out that this vertical flux of cross-stream vorticity component is (minus) the cross-stream flux of vertical vorticity component. The divergence of the latter at the lateral edges of a hydraulic jump of finite cross-stream extent produces time-mean vertical vorticity.) Hence, the line of inquiry devolves to a search for the source of the cross-stream vorticity that is being fluxed downward. For a hydraulic jump in the Ice of a submerged obstacle, the authors argue that ...
Skeletal Abnormalities of Short Spined Turkeys.

SummaryA simple autosomal recessive lethal mutation that causes crowding together of the vertebrae with consequent shortening of the neck and body is described. The percentage of ash in the wing and leg bones was approximately the same as in the normal embryos, but the percentage of ash was less in the scapula, ilium, and ischium than in the corresponding bones of the normal embryos.
Three views of viscoelasticity for Cox-Merz materials

A slight rearrangement of the classical Cox and Merz rule suggests that the shear stress value of steady shear flow, $\tau (\mathop \gamma \limits^. )$ , and complex modulus value of small amplitude oscillatory shear, G ∗ (ω) = (G′2 + G″2)1/2, are equivalent in many respects. Small changes of material structure, which express themselves most sensitively in the steady shear stress, τ, show equally pronounced in linear viscoelastic data when plotting these with G ∗ as one of the variables. An example is given to demonstrate this phenomenon: viscosity data that cover about three decades in frequency get stretched out over about nine decades in G ∗ while maintaining steep gradients in a transition region. This suggests a more effective way of exploiting the Cox–Merz rule when it is valid and exploring reasons for lack of validity when it is not. The τ −G ∗ equivalence could also further the understanding of the steady shear normal stress function as proposed by Laun.
Two-Way Multidimensional Scaling: A Review

Multidimensional scaling (MDS) is a technique used to extract a set of independent variables from a proximity matrix or matrices. Applications of MDS are found in a wide range of areas, including visualization, pattern analysis, data preprocessing, scale development, cybernetics, and localization. The overall rationale behind the paper is to help share innovations across disciplines. We survey and synthesize MDS methods from the academic areas of psychometrics, statistics, and computing. We define classical MDS and distance-based MDS. We then introduce basic MDS formulations and functions. We survey MDS techniques designed for nonlinear data and describe distance-based MDS in terms of minimizing the energy function in a spring system. We describe completely nonmetric MDS techniques for ordinal input data and describe how MDS solutions can be compared using ordinal neighborhood information. We describe optimization methods for fitting MDS models, covering both continuous optimization techniques and combinatorial techniques. We give several illustrative applications of MDS from the areas of cybernetics, air traffic control, molecular chemistry, robotics, and network localization. We link this work to the techniques described in the previous sections of the paper. We list a wide range of currently available MDS software and discuss possible future work in the area.
Learning complementary multiagent behaviors: a case study

As the reach of multiagent reinforcement learning extends to increasingly complex tasks, it is likely that the diverse challenges encountered can only be surmounted by combining the strengths of different learning methods. We consider this aspect of learning through the case study of Keepaway, a popular benchmark for multiagent reinforcement learning from the robot soccer domain. Whereas previous successful results in this domain have limited learning to an isolated, infrequent decision that amounts to a turn-taking behavior (Pass), we expand the agents' learning capability to include the more ubiquitous action of moving without the ball (GetOpen), such that at any given time, multiple agents are executing learned behaviors simultaneously. We introduce a policy search method for learning GetOpen to complement the temporal difference learning approach employed for learning Pass [4]. The learned GetOpen policy matches the best hand-coded policy for this task, and outperforms the best policy found when Pass is learned. We demonstrate that Pass and GetOpen can be learned simultaneously, and indeed that these learned behaviors specialize towards the counterpart behaviors with which they are trained.
Substrate effects on the electron-beam-induced deposition of platinum from a liquid precursor.

Focused electron-beam-induced deposition using bulk liquid precursors (LP-EBID) is a new nanofabrication technique developed in the last two years as an alternative to conventional EBID, which utilizes cumbersome gaseous precursors. Furthermore, LP-EBID using dilute aqueous precursors has been demonstrated to yield platinum (Pt) nanostructures with as-deposited metal content that is substantially higher than the purity achieved by EBID with currently available gaseous precursors. This advantage of LP-EBID—along with the ease of use, low cost, and relative innocuousness of the liquid precursors—holds promise for its practical applicability in areas such as rapid device prototyping and lithographic mask repair. One of the feasibility benchmarks for the LP-EBID method is the ability to deposit high-fidelity nanostructures on various substrate materials. In this study, we report the first observations of performing LP-EBID on bare and metal-coated silicon–nitride membranes, and compare the resulting Pt deposits to those obtained by LP-EBID on polyimide membranes in terms of nucleation, morphology, size dependence on electron dose, and purity.
Recurrence and interoccurrence behavior of self-organized complex phenomena

Abstract. The sandpile, forest-fire and slider-block models are said to exhibit self-organized criticality. Associated natural phenomena include landslides, wildfires, and earthquakes. In all cases the frequency-size distributions are well approximated by power laws (fractals). Another important aspect of both the models and natural phenomena is the statistics of interval times. These statistics are particularly important for earthquakes. For earthquakes it is important to make a distinction between interoccurrence and recurrence times. Interoccurrence times are the interval times between earthquakes on all faults in a region whereas recurrence times are interval times between earthquakes on a single fault or fault segment. In many, but not all cases, interoccurrence time statistics are exponential (Poissonian) and the events occur randomly. However, the distribution of recurrence times are often Weibull to a good approximation. In this paper we study the interval statistics of slip events using a slider-block model. The behavior of this model is sensitive to the stiffness α of the system, α=kC/kL where kC is the spring constant of the connector springs and kL is the spring constant of the loader plate springs. For a soft system (small α) there are no system-wide events and interoccurrence time statistics of the larger events are Poissonian. For a stiff system (large α), system-wide events dominate the energy dissipation and the statistics of the recurrence times between these system-wide events satisfy the Weibull distribution to a good approximation. We argue that this applicability of the Weibull distribution is due to the power-law (scale invariant) behavior of the hazard function, i.e. the probability that the next event will occur at a time t0 after the last event has a power-law dependence on t0. The Weibull distribution is the only distribution that has a scale invariant hazard function. We further show that the onset of system-wide events is a well defined critical point. We find that the number of system-wide events NSWE satisfies the scaling relation NSWE ∝(α-αC)δ where αC is the critical value of the stiffness. The system-wide events represent a new phase for the slider-block system.
Effect of peptide loading and surfactant concentration on the characteristics of physically crosslinked hydrogel.

The purpose of this study was to investigate the effect of varying drug load and concentration of a surfactant (sodium lauryl sulfate [SLS]) on the release characteristics of a model peptide (bovine serum albumin [BSA]), and study the net effects of the swelling properties of the hydrogel matrix [poly(vinyl alcohol) (PVA)]. The PVA hydrogel was prepared by a freeze-thaw process in the absence of a chemical crosslinking agent. The effect of protein loading on drug release was examined at three levels (0.65, 1.3, and 2%), whereas the effect of SLS was studied at four levels (0, 0.07, 0.13, and 0.26%). The baseline time for reaching equilibrium swelling was 48 hr for the hydrogel containing 0.65% BSA, and the equilibrium swelling time decreased significantly as the protein load was increased to 2%. The net effect of increased BSA concentrations resulted in faster BSA dissolution from the hydrogel matrix. The equilibrium-swelling ratio decreased from 21 to 10% when SLS was added to the PVA solution, which resulted in a reduction in the extent of equilibrium swelling; however, the time to reach equilibrium swelling was increased. The investigation provided a mechanistic basis toward the development of a hydrogel formulation by altering the concentration of two fundamental components, i.e., drug and surfactant, within the delivery system.
Ecological effects of changes in fire regimes in Pinus ponderosa ecosystems in the Colorado Front Range

Abstract Question: What is the relative importance of low- and high-severity fires in shaping forest structure across the range of Pinus ponderosa in northern Colorado? Location: Colorado Front Range, USA. Methods: To assess severities of historic fires, 24 sites were sampled across an elevation range of 1800 to 2800 m for fire scars, tree establishment dates, tree mortality, and changes in tree-ring growth. Results: Below 1950 m, the high number of fire scars, scarcity of large post-fire cohorts, and lack of synchronous tree mortality or growth releases, indicate that historic fires were of low severity. In contrast, above 2200 m, fire severity was greater but frequency of widespread fires was substantially less. At 18 sites above 1950 m, 34 to 80% of the live trees date from establishment associated with the last moderate- to high-severity fire. In these 18 sites, only 2 to 52% of the living trees pre-date these fires suggesting that fire severities prior to any effects of fire suppression were sufficie...
Control of Locomotion In Vitro: II. Chemical Stimulation

Previous studies have described the presence of alternating activity induced in left and right ventral roots of the neonate rat in vitro brainstem-spinal cord preparation, following application of certain neuroactive substances to the bathing solution. The present findings show the presence of chemically induced, adult-like coordinated airstepping demonstrated by electromyographic recordings in the hindlimb-attached in vitro brainstem-spinal cord preparation. Analysis of muscular activity demonstrated alternation between antagonists of one limb and between agonists of different limbs, as well as a proximodistal delay in agonists active at different joints of the same limb. Neuroactive agents were applied independently to either the brainstem or spinal cord bath. The substances surveyed in the present studies included some of those used previously, as well as additional compounds: bicuculline and picrotoxin (γ-aminobutyric acid-ergic antagonists), N-methyl-D-aspartic acid (excitatory amino acid agonist), s...
Role for Sulfatides in Platelet Aggregation

Background— Sulfatides are sulfated glycosphingolipids present on the surface of oligodendrocytes, renal tubular cells, and certain tumor cells. They appear to be involved in nerve conduction and cell adhesion, but their precise physiological function is not known. Methods and Results— Here, we show a novel role for sulfatides as a major ligand for P-selectin in platelet adhesion and aggregation. Sulfatides are expressed on the platelet surface, and platelets expressing sulfatides adhere to P-selectin. Both sulfatide micelles and sulfatide-binding recombinant malaria circumsporozoite protein (MCSP) inhibit this adhesion. In parallel, platelets and CHO cells expressing P-selectin adhere to sulfatides, and anti-P-selectin antibodies inhibit this adhesion. Furthermore, both anti-P-selectin antibodies and sulfatide antagonist MCSP significantly reverse platelet aggregation induced by ADP, collagen, or thrombin receptor-activating peptide, suggesting that sulfatide-P-selectin interactions are necessary for the...
Job Leaves and the Limits of the Family and Medical Leave Act The Effects of Gender, Race, and Family

This article examines the need for and use of leaves designated by the Family and Medical Leave Act. Using national data, we show that women, parents, those with little income, and African Americans are particularly likely to perceive a need for job leaves. However, it is married—not single—women and Whites who are particularly likely to take such leaves. The authors suggest that this disjunction between need and use is a consequence of the construction of leave policy—that it provides for only short, unpaid leaves for a narrow slice of workers and those politically constructed as “family”—and the unresponsiveness of workplaces. These limits likely reinforce inequality based on gender, race, and family status.
Interactions of Implanted Carbon with Oxygen and Nitrogen in Silicon

Carbon has been implanted into Si to overlap implanted concentrations of oxygen and nitrogen. Impurity incorporation and interactions produced by implantation at 50 °C, and upon subsequent annealing to 900 °C, were monitored by infrared absorption. Implantation with 0 and C introduces absorption bands for C-0 centers in addition to those for substitutional C, interstitial 0, and 0-vacancy centers. These centers are removed by annealing. The major effect of C in N-implanted layers is a suppression of absorption bands associated previously with N aggregates. There is, apparently, a strong interaction between C and displacement defects which can alter defect reordering and control the loss of C from substitutional sites.
Prairie dog alarm calls encode labels about predator colors

Some animals have the cognitive capacity to differentiate between different species of predators and generate different alarm calls in response. However, the presence of any addition information that might be encoded into alarm calls has been largely unexplored. In the present study, three similar-sized human females walked through a Gunnison’s prairie dog (Cynomys gunnisoni) colony wearing each of three different-colored shirts: blue, green, and yellow. We recorded the alarm calls and used discriminant function analysis to assess whether the calls for the different-colored shirts were significantly different. The results showed that the alarm calls for the blue and the yellow shirts were significantly different, but the green shirt calls were not significantly different from the calls for the yellow shirt. The colors that were detected, with corresponding encoding into alarm calls, reflect the visual perceptual abilities of the prairie dogs. This study suggests that prairie dogs are able to incorporate labels about the individual characteristics of predators into their alarm calls, and that the complexity of information contained in animal alarm calls may be greater than has been previously believed.