cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis of RGD analogs as potential vectors for targeted drug delivery.

RGD analogs bind to integrin receptors with high affinity and therefore have the potential to be used as vectors for the targeted delivery of pharmaceutical agents to designated sites. Critical to this application is the ability to synthesize RGD analogs with different side chain functional groups that allow for the ready tethering of pharmaceutical agents without sacrificing their affinity for the target receptor significantly. A series of RGD analogs intended to be used as delivery vectors of pharmaceutical agents were prepared and evaluated for their ability to inhibit platelet aggregation by binding to glycoprotein IIb/IIIa. Among them, compound 11 showed the lowest IC50 against platelets activated by ADP. It was found that such RGD analogs could tolerate side chain modification fairly well with various functional groups attached such as amide, amine, ester, protected amine and poly(ethylene glycol). The fact that the compound with a side chain modification of poly(ethylene glycol) retained high affinity for glycoprotein IIb/IIIa (IC50 150 nM) suggests the feasibility of tethering fairly large pharmaceutical agents to such RGD analogs without significant sacrifice of their affinity to the intended receptor.
Software-based robust global motion estimation for real-time video target tracking

In video tracking systems using image subtraction for motion detection, the global motion is usually estimated to compensate for the camera motion. The accuracy and robustness of the global motion compensation critically affects the performance of the target tracking process. The global motion between video frames can be estimated by matching the features from the image background. However, the features from moving targets contain both camera and target motion and should not be used to calculate the global motion. Sparse optical flow is a classical image matching method. However, the image features selected by optical flow may come from moving targets, with some of the image features matched not being accurate, which leads to poor video tracking performance. Least Median of Square (LMedS) is a popular robust linear regression model and has been applied to real-time video tracking systems implemented in hardware to process up to 7.5 frames/second. In this paper, we use a robust regression method to select features only from the image background for robust global motion estimation, and we develop a real-time (10 frames/second), software-based video tracking system that runs on an ordinary Windows-based general-purpose computer. The software optimization and parameter tuning for real-time execution are discussed in detail. The tracking performance is evaluated with real-world Unmanned Air Vehicle (UAV) video, and we demonstrate the improved global motion estimation in terms of accuracy and robustness.
Bounding and Comparing Methods for Correlation Clustering Beyond ILP

We evaluate several heuristic solvers for correlation clustering, the NP-hard problem of partitioning a dataset given pairwise affinities between all points. We experiment on two practical tasks, document clustering and chat disentanglement, to which ILP does not scale. On these datasets, we show that the clustering objective often, but not always, correlates with external metrics, and that local search always improves over greedy solutions. We use semi-definite programming (SDP) to provide a tighter bound, showing that simple algorithms are already close to optimality.
Ancient Chinese observations of physical phenomena attending solar eclipses

The realization that solar activity probably undergoes changes in qualitative character on time scales greater than the 11 or 22 year cycle but short compared to the duration of recorded history gives renewed importance to historical documents describing the state of solar activity. Modern eclipse observation reveal the presence of solar activity through the appearance of coronal structures and prominences. It has been widely remarked that eclipse records prior to the 18th century are uniformly silent on these conspicuous solar eclipse features, raising the possibility, however unlikely, that a change in solar activity has occurred which rendered them only recently noticeable. We present here material from ancient Chinese sources, primarily astrological, that describe phenomena attending solar eclipses that are almost certainly coronal structures and prominences. Thus, these aspects of the present character of solar activity have apparently occurred at other times in history, if not continuously.
Acquisition and presentation of follicular dendritic cell–bound antigen by lymph node–resident dendritic cells

Follicular dendritic cells (DCs [FDCs]) are prominent stromal cell constituents of B cell follicles with the remarkable ability to retain complement-fixed antigens on their cell surface for extended periods of time. These retained immune complexes have long been known to provide the antigenic stimulus that drives antibody affinity maturation, but their role in cellular immunity has remained unclear. In this study, we show that FDC-retained antigens are continually sampled by lymph node–resident DCs for presentation to CD8 T cells. This novel pathway of antigen acquisition was detectable when FDCs were loaded with purified antigens bound into classical antigen–antibody immune complexes, as well as after pregnancy, when they are loaded physiologically with antigens associated with the complement-fixed microparticles released from the placenta into maternal blood. In both cases, ensuing antigen presentation was profoundly tolerogenic, as it induced T cell deletion even under inflammatory conditions. These results significantly broaden the scope of FDC function and suggest new ways that the complement system and persistent antigen presentation might influence T cell activation and the maintenance of peripheral immune tolerance.
Correction to “The magmatic Rayleigh number and time dependent convection in cooling lava lakes”

This is, in fact, the equation that is plotted in Figure 4 for comparison with the finite element model. In addition, the last sentence of the "Thermal-Kinematic Regime" section on page 917 should now read: "Because interior velocity tends to scale as 1/$ 2, one might expect that w a R•a• 5for. • = .175. Rather, it is found that w a Ra• in line with isoviscous theory." xnese changes are only typographic and do not affect the conclusions of the paper.
Characterization of myosin-II binding to Golgi stacks in vitro.

In addition to important roles near the actin-rich cell cortex, ample evidence indicates that multiple myosins are also involved in membrane movements in the endomembrane system. Nonmuscle myosin-II has been shown to have roles in anterograde and retrograde trafficking at the Golgi. Myosin-II is present on Golgi stacks isolated from intestinal epithelial cells and has been localized to the Golgi in several polarized and unpolarized cell lines. An understanding of roles of myosin-II in Golgi physiology will be facilitated by understanding the molecular arrangement of myosin-II at the Golgi. Salt-washing removes endogenous myosin-II from isolated Golgi and purified brush border myosin-II can bind in vitro. Brush border myosin-II binds to a tightly bound Golgi peripheral membrane protein with a K1/2 of 75 nM and binding is saturated at 0.7 pmol myosin/μg Golgi. Binding studies using papain cleavage fragments of brush border myosin-II show that the 120-kDa rod domain, but not the head domain, of myosin heavy chain can bind directly to Golgi stacks. The 120-kDa domain does not bind to Golgi membranes when phosphorylated in vitro with casein kinase-II. These results suggest that phosphorylation in the rod domain may regulate the binding and/or release of myosin-II from the Golgi. These data support a model in which myosin-II is tethered to the Golgi membrane by its tail and actin filaments by its head. Thus, translocation along actin filaments may extend Golgi membrane tubules and/or vesicles away from the Golgi complex. Cell Motil. Cytoskeleton 60:222–235, 2005. © 2005 Wiley-Liss, Inc.
Variable Diastolic Ventricular Compliance : a General Property of Mammalian Cardiac Muscle

STUDIES of the extensibility of quiescent cardiac muscle have been the cause of recurrent controversy. Starling's law of the heart relates the energy of contraction to the length the muscle fibres attain just prior to contraction. In studies of the regulation of cardiac contraction the assumption is made that measurement of pressure within the ventricle during diastole provides an accurate index of ventricular volume and that changes in pressure thus predict changes in fibre length1. This assumption requires that the compliance of ventricular muscle, that is, the change in length for a given change in force, remain constant throughout diastole in spite of changing conditions. Although there have been indications in the older literature that the compliance or ‘tone’ of the heart may change during diastole as a dynamic variable2, present interpretations of cardiac performance are based on the existence of constant diastolic extensibility3.
Bacteriophage Mu: a transposing phage that integrates like retroviruses

Bacteriophage Mu uses a specialized type of genetic recombination called transposition to both integrate its DNA into that of the host and to amplify its DNA during lytic growth. Studies with Mu have defined the basic mechanisms of the DNA cleavage and joining reactions needed for transposition. These mechanisms appear to be used by many transposable elements that populate prokaryotic and eukaryotic hosts. Mu transposition is also very similar to retroviral integration. This conservation in the reaction mechanism is reflected in the transposition proteins. Mu transposase carries an acidic amino acid motif which is required for catalysis that is found in many other transposases and the retroviral integrases. Regulation of Mu transposition by the controlled assembly of the active transposase tetramer and by interactions between the transposase and MuB protein are also discussed.
On an iterative method for saddle point problems

Convergence behavior of a nested iterative scheme presented in a paper by Bank, Welfert and Yserentant is studied. It is shown that this scheme converges under conditions weaker than that stated in their paper.
The culture of crime: Examining representations of Irish Travelers in Traveller and The Riches

Irish Travelers are frequently equated with crime. This culture-of-crime stereotype is reproduced through media culture. In this article I will analyze the 1997 film Traveller and the first season of the 2007 television series The Riches to see how the criminal stigma is repeatedly (re)ascribed to Irish Travelers. I identify two cultural discourses in Traveller . First, the “culture as practice” discourse grants admission to a cultural group based on what one does. Second, the “culture as nature” discourse views cultural belonging in a biologically deterministic fashion. These two discourses overlap, and Irish Traveler culture is still depicted as a culture of crime. The Riches reproduces this stereotype, as the only way Irish Travelers can lead a “normal” life is too steal a buffer’s identity. Both of these examples lead to questioning whether invisibility or visibility solely as criminals is preferable.
Secular trends in leisure-time physical activity in men and women across four decades

Abstract Background We examined secular trends in leisure-time physical activities (LTPA) in health-conscious men ( n = 1359) from 1958 to 1998 and in women ( n = 839) from 1978 to 1998, who were participants of the Baltimore Longitudinal Study of Aging (BLSA). Methods LTPA was the self-reported time spent performing 97 activities, and was converted to metabolic equivalent of oxygen uptake (MET) minutes per day. Evaluations of LTPA were averaged for each decade. The prevalence of a sedentary lifestyle in each decade was assessed based on compliance with widely publicized recommendations for participation in physical activity. All analyses were adjusted for age, education, and race differences across decades. Results Median high-intensity LTPA, defined as activities ≥6 METs, increased from 30 to 80 MET min/day from the 1960s to the 1990s for men ( P Conclusions In a health-conscious sample across a broad age range, national recommendations appear to have made modest progress in decreasing the proportion of sedentary adults.
Manganese-55 NMR linewidths and quadrupole coupling constants in solution; partial field gradient parameters in Mn(I) complexes

Abstract Newly measured and literature values for 55 Mn NMR Linewidths of 55 Mn-containing organometallic compounds in tetrahydrofuran solution are compared with measured quadrupole coupling constants. A linear relationship between ( e 2 gQ / h ) 2 and linewidth is observed; the slope corresponds to a rotational correlation time τ q of 1.3 psec. Using scaled partial quadrupole splitting (pqs) parameters for X derived from Mossbauer data on Fe(II) complexes, the pqs parameter for CO in XMn(CO) 5 complexes was determined to be −0.50 mm sec −1 . On the basis of this work, the sign and magnitude of the quadrupole coupling constant in XMn(CO) 5 compounds can be readily predicted from use of pqs parameters derived for Fe(ll), and tested by observation of 55 Mn NMR Linewidths in THF solutions.
Morphological and biochemical changes during formocresol induced cell death in murine peritoneal macrophages: apoptotic and necrotic features

The present study was conducted to investigate the role of Formocresol (FC)-induced apoptosis and necrotic cell death in murine peritoneal macrophages (pMo). Macrophages were cultured with 1:100 FC for 2 to 24 h. The viability (trypan blue assay), cell morphology (scanning electronic microscope), and apoptotic and necrotic indexes (light and fluorescent microscopy) were determined at different scheduled times. Simultaneously, the expressions of proteins related to stress, survival, and cell death were measured by western blotting. FC-exposed macrophages exhibited maximal apoptosis from 2 to 6 h, coincident with Bax overexpression (P < 0.001). Additionally, Bcl-x(L) showed maximal expression between 12 and 24 h suggesting its survival effect in pMo. The lowest pMo viability and the increment of the necrotic rate from 4 to 12 h were observed in accordance to Fas and Hsp60 overexpressions. In summary, all the experimental data suggest that two different pathways emerge in pMo exposed to FC, one leading Bax-dependent apoptosis (2-6 h) and the other one favoring necrosis (4-18 h), related to Fas-receptor and Hsp60 stress signal.
Schwann cell proliferation in the postnatal mouse: timing and topography.

Abstract We examined the intensity and timing of Schwann cell proliferation in the developing mouse using autoradiographic techniques. Schwann cell labeling indices were highest in the first few postnatal days and decreased gradually thereafter. Highest labeling indices and onset of myelination occurred later in the C57B16 C3H than the Balb c mouse, suggesting strain differences in Schwann cell behavior. The timing of Schwann cell proliferation was similar from L5 roots to the posterior tibial nerves, with no evidence of a proximaldistal gradient during this period. Cessation of proliferation was not abrupt, but occurred throughout the first 10 postnatal days. These observations can be explained by the presence of a fixed-size proliferating Schwann cell pool, in which half of all daughter cells cease division with each cell cycle and differentiate into their adult roles.
The scaled-Q method for solving l/sub 1/ optimization problems

We explore the scaled-Q approach for solving MIMO l/sub 1/ optimal control problems. This method was introduced by the author in order to alleviate many of the difficulties facing the numerical solution of optimal l/sub 1/ control problems. In particular, this approach does not require computations of multivariable zeros and their directions. It also avoids the pole-zero cancellation difficulties that existing methods based on zero-interpolation face when attempting to recover the optimal controller from an optimal closed-loop map. Since the scaled-Q approach is based on solving a regularized auxiliary problem for which the solution is always guaranteed to exist, it can be used no-matter where the system zeros are (including the stability boundary). Upper and lower bounds which converge to the optimal cost are provided, and all solutions are based on finite dimensional linear programming for which efficient software exists.
The Role of Modulatory Calcineurin-Interacting Proteins in Calcineurin Signaling

Modulatory calcineurin-interacting proteins (MCIPs), also known as the Down syndrome critical region 1 (DSCR1) and DSCR1-like proteins, are a recently described family of small, structurally related proteins that are preferentially expressed in heart, skeletal muscle, and brain. MCIP proteins can bind to and inhibit calcineurin, a calcium/calmodulin-regulated serine/threonine protein phosphatase that is activated during cardiac hypertrophy and failure. Transcription of the mammalian MCIP1 gene is induced by calcineurin, suggesting that it functions as an endogenous feedback regulator of calcineurin signal transduction. Forced expression of human MCIP1 protein in the hearts of transgenic mice attenuates the hypertrophic response to a broad range of stimuli. This review summarizes work from a number of laboratories on the structure, regulation, and function of MCIP proteins.
Observational study of bone accretion during successful weight loss in obese adolescents.

Objective: To assess bone mineral content (BMC) among obese adolescents who lose weight during a critical period for bone accretion. Methods and Procedures: Whole body, lumbar spine, lower, and upper limb BMC were measured in 62 obese adolescents who completed an intensive 12-month weight loss trial. BMC was adjusted for height (z-scores) using data from a reference group of 66 adolescents (who were 18% overweight). Results: At baseline, the BMC of the obese group was higher than the reference group. During the 12-month weight loss program, unadjusted BMC increased among the obese adolescents, despite successful weight loss. After adjustment for height, whole body BMC did not change significantly from baseline to 12 months (mean ± s.d.: 1.08 ± 0.67 to 1.06 ± 0.67, P = 0.7). Region-specific BMC-for-height however decreased for the lower (1.07 ± 0.57 to 0.95 ± 0.59, P < 0.001) and upper (1.29 ± 0.56 to 1.18 ± 0.57, P = 0.01) limbs, but lumbar spine BMC-for-height increased (0.14 ± 1.06 to 0.40 ± 0.94, P < 0.001). These changes were largely and independently explained by changes in lean and fat mass. Discussion: This study confirms that obese adolescents have high BMC for height and suggests that, unlike adults, their BMC continues to increase during weight loss and remains higher than the BMC of a reference group. After adjustment for growth-related changes, lower and upper limb BMC appears to decrease, while lumbar spine BMC appears to increase. These results suggest that to optimize the health benefits of weight loss among obese adolescents, their bone health should be better understood and addressed.
Ecto‐enzyme and signaling functions of lymphocyte CD 7 3

CD73 or ecto-5'-nucleotidase (5'-NT) is a widely expressed ecto-enzyme which catalyzes the dephosphorylation of AMP and other nucleoside monophosphates. CD73 participates in purine salvage through this enzymatic activity, supplying cells with precursors for energy metabolism and nucleic acid biosynthesis. As an enzyme that produces adenosine, CD73 can also regulate adenosine receptor engagement in many tissues. However, CD73 also has functions independent of its enzyme activity. Like many glycosyl phosphatidylinositol (GPI)-anchored molecules, it transmits potent activation signals in T cells when ligated by antibodies. Less compelling evidence suggests that CD73 may function as a cell adhesion molecule. In the human immune system, CD73 is expressed on subsets of T and B cells, on germinal center follicular dendritic cells, and on thymic medullary reticular fibroblasts and epithelial cells. Many challenging areas remain to be explored before the role of CD73 in the immune system will be fully understood. These include an evaluation of the role of adenosine receptors in lymphoid development, the identification of physiological CD73 ligands, a functional assessment of the GPI anchor, and an analysis of the intricate cell-type-specific and developmental regulation of CD73 expression.
A Role for Corticosterone in Impaired Intestinal Immunity and Barrier Function in a Rodent Model of Acute Alcohol Intoxication and Burn Injury

Alcohol (EtOH) intoxication and burn injury independently activate hypothalamic–pituitary–adrenal (HPA) axis, and glucocorticoids, the end product of the HPA axis, play a role in shaping the immune response under those conditions. By utilizing a rat model of acute EtOH intoxication and burn injury, studies in our laboratory have investigated the role of corticosterone (i.e., glucocorticoids in rodents) in altered intestinal immunity and barrier function following a combined insult of EtOH and burn injury. Results from these studies suggest that EtOH intoxication prior to burn injury augments corticosterone release, which in turn suppresses intestinal T cell function by inhibiting mitogen-activated protein kinase (i.e., p38 and ERK) pathway. Furthermore, we found that corticosterone does not directly alter the intestinal barrier function; rather, it up-regulates interleukin-18, which then directly or indirectly contributes to impaired intestinal barrier function. The loss of intestinal immunity/barrier function may result in increased bacterial translocation and thereby contribute to postinjury pathogenesis, leading to sepsis and organ dysfunction in burn patients as well as in patients with a history of EtOH intoxication.
On the mobility of water molecules in the transition layer between ice and a solid surface

Abstract Experiments which demonstrate the existence of a mobile transition layer between ice and a solid surface are discussed. Water is shown to migrate in the transition layer under the influence of both electrical and temperature gradients. Particles embedded in ice are found to migrate to the warm side under the influence of a temperature gradient, and the same particles are under certain circumstances driven in front of an ice-water interface. The mobility of the transition layers could also be evaluated from water movement in frozen soils under temperature gradients, as well as from electroosmosis.
The Rate of Decay of Fission Products

There are two ways to describe the total β- and γ-radiation emitted by the fission products. The first, more accurate method describes it as the sum of radiations emitted by the differnt fission products. The second, less accurate method considers the fission products as a sort of statistical assembly and tries to arrive at once at the total radiation from all the fission products together. While this second method is unquestionably less complete taht the first one, it is so much simpler that it is much preferable in most practical calculations. Its validity is limited, of course, to times during which the radiation is emitted by many nuclei. at very long times after irradiation, when most of the radiation is caused by a few surviving species of nuclei, the first method is definitely preferable.
Structured security testing in the smart grid

The advanced metering infrastructure (AMI) is revolutionizing electrical grids. Intelligent AMI “smart meters” report real time usage data that enables efficient energy generation and use. However, aggressive deployments often outpace security efforts: new devices from a dizzying array of vendors are being introduced into grids with limited understanding of the security problems they represent. In this paper we develop an archetypal attack tree approach to guide penetration testing across multiple-vendor implementations of a technology class. In this, we graft archetypal attack trees modeling broad adversary goals and attack vectors to vendor-specific concrete attack trees. Evaluators then use the grafted trees as a roadmap to penetration testing. Our experiments with multiple vendors generate real attack scenarios using vulnerabilities identified during directed penetration testing, e.g., manipulation of energy usage data, spoofing meters, and extracting sensitive data from internal registers. We provide a detailed example of one such attack as tested using our developed methodology.
Local positive feedback by calcium in the propagation of intracellular calcium waves.

In many types of eukaryotic cells, the activation of surface receptors leads to the production of inositol 1,4,5-trisphosphate and calcium release from intracellular stores. Calcium release can occur in complex spatial patterns, including waves of release that traverse the cytoplasm. Fluorescence video microscopy was used to view calcium waves in single mouse neuroblastoma cells. The propagation of calcium waves was slowed by buffers that bind calcium quickly, such as BAPTA, but not by a buffer with slower on-rate, EGTA. This shows that a key feedback event in wave propagation is rapid diffusion of calcium occurring locally on a scale of
Left ventricular hypertrophy in hypertensive children and adolescents: predictors and prevalence.

Left ventricular hypertrophy is an independent predictor of cardiovascular morbidity and mortality in adults. In children, the primary correlate of left ventricular mass (LVM) is lean body mass, but fat mass, gender and systolic blood pressure are also contributors. LVM can be estimated from echocardiographic measurements, and by indexing this allometrically to height to the 2.7 power, the left ventricular mass index (LVMI) can be calculated. LVMI optimizes detection of left ventricular hypertrophy with established normal curves for children from birth to 18 years. In children with sustained hypertension, 8–41 % have LVMI above the 95th percentile and in 10–15.5 % of these, LVMI is elevated above levels associated with increased mortality in adults. The presence of obesity is associated with higher LVMI than is found in children with hypertension alone. In children with chronic kidney disease, left ventricular hypertrophy develops relatively early and becomes more prevalent as kidney function decreases. In summary, left ventricular hypertrophy is a sensitive marker of target organ damage in children with BP elevation, obesity and chronic kidney disease providing important management information.
Heuristic improvement through triangulation

This paper presents a method for improving heuristics using a triangulation technique. Instead of using a heuristic to directly estimate distance (X1, X2) between nodes X1 and X2, the proposed tech...
Discovery, characterization and modelling of novel shape memory behaviour of fcc metal nanowires

Novel shape memory behaviour was discovered recently in single-crystalline fcc nanowires of Cu, Ni and Au with lateral dimensions below 5 nm. Under proper thermomechanical conditions, these wires can recover elongations up to 50%. This phenomenon only exists at the nanoscale and is associated with reversible lattice reorientations within the fcc lattice structure driven by surface stresses. Whereas the propagation of partial dislocations and twin planes specific to fcc metals are the required mechanism, only materials with higher propensities for twinning (e.g. Cu and Ni) show this behaviour and those with lower propensities for twinning (e.g. Al) do not. This paper provides an overview of this novel behaviour with a focus on the transformation mechanism, driving force, reversible strain, size and temperature effects and energy dissipation. A mechanism-based micromechanical continuum model for the tensile behaviour is developed. This model uses a decomposition of the lattice reorientation process into a reversible, smooth transition between a series of phase-equilibrium states and a superimposed irreversible, dissipative propagation of a twin boundary. The reversible part is associated with strain energy functions with multiple local minima and quantifies the energy conversion process between the twinning phases. The irreversible part is due to the ruggedness of the strain energy landscape, associated with dislocation nucleation, gliding and annihilation, and characterizes the dissipation during the transformation. This model captures all major characteristics of the behaviour, quantifies the size and temperature effects and yields results which are in excellent agreement with data from molecular dynamics simulations.
Teaching asynchronous design in digital integrated circuits

To introduce the basis of asynchronous digital circuit design in an electrical engineering curriculum, Null Convention Logic is presented as an innovative asynchronous paradigm. The design flow from concept to circuit implementation is discussed. First, two completeness criteria are required for speed independency: symbolic completeness of expression and completeness of input. Second, threshold gates with hysteresis are primary components, which are used to build logic gates, full adder, and registers. As an example, a 4 /spl times/ 4 multiplier is constructed based on these threshold gates. Finally, an example of very-high-speed integration circuit hardware description language (VHDL) simulation is given to help students practice and understand the asynchronous design methodology.
Finding fulfillment: women's self-efficacy beliefs and career choices in chemistry

Research has shown that self-efficacy beliefs are effective predictors of academic major and career choices in middle school, high school, and early college populations. There is little understanding, however, of how these beliefs develop and what influence they have on academic and career choices in women at the advanced undergraduate and graduate levels. This qualitative study identified key factors that contributed to women chemists' academic and career decisions. Participants completed a chemistry self-efficacy survey and participated in three in-depth interviews. The results indicated that the participants' efficacy beliefs were positively influenced primarily by mastery experiences and social support and were undermined by inaccurate social comparisons. Efficacy beliefs were found to help steer them towards different careers, but ultimately value judgments were more influential in directing their career choice. These women did not value the outcomes of chemistry research or find scientific research intrinsically fulfilling, which led them to choose careers that they felt more directly benefitted humanity. Suggestions for showing the value of chemistry research in the classroom and the laboratory are offered.
A unified view of craton evolution motivated by recent deep seismic reflection and refraction results

SUMMARY An attempt is made to integrate recent continental seismic reflection, refraction, and geologic observations into a unified scheme of craton evolution. 1 Nascent continental crust of basaltic bulk composition is produced in island arcs. As with oceanic crust, Moho in this setting lies within the magmatic edifice and corresponds to a downward transition from dominantly mafic cumulate rocks above to dominantly ultramafic cumulates below. The petrologic crust/mantle boundary, lying ∼25 per cent deeper in the lithosphere, has no seismic expression, and corresponds to a depositional/magmatic contact between cumulate ultramafic rocks above and residual mantle (ultramafic tectonite) below. Both contacts are presumably extensively disrupted by magmatic injection. 2 Island arcs are amalgamated into continents at collision zones. Delamination of the lower mafic/ultramafic portion of the crust along with the mantle lithosphere during ‘hard’ collisions acts as a mechanical refining process that pushes the bulk crust toward intermediate composition. 3 Subsequent extensional collapse of the overthickened crust together with thermal re-equilibration of the lithosphere results in ‘youthful’ stable continental crust, which is ∼30 km thick with its top surface awash at sea level and has the bulk composition of andesite. This crust characteristically exhibits extensional features (half grabens) in the upper portion, and is prominently laminated in the lower portion due to the injection of modest amounts of basaltic magma in the form of sills during delamination. The Moho and petrologic base of the crust coincide in this setting and can correspond to either a ductile high-strain zone or intrusive contact separating mafic/intermediate composition material above from fertile mantle (lherzolite) below. 4 Subsequent ‘cratonization’ is the cumulative effect of episodic injection of the crust by mafic magma at intervals of hundreds of Myr (as manifest by the ubiquitous overlapping dike swarms of the Precambrian shields). This results in net long-term thickening of the crust by underplating, shifts the bulk crust back toward mafic composition, periodically produces a new deeper Moho and petrologic crust/mantle boundary that do not coincide, and through repeated dike injection disrupts pre-existing laminated reflectors. The first magmatic injection event ‘sweats out’ the light melting fraction in the pre-existing andesitic crust, producing voluminous granitic magmatism typified by the great Proterozoic anorogenic granite/rhyolite provinces. Subsequent injection events into refractory crust produce uplift with attendant erosional denudation of supracrustal sequences. The cumulative result is shield-type crust in which intermediate crustal levels are exposed over wide areas, crustal thickness commonly exceeds 40 km, average crustal velocity is somewhat higher than in younger stable crust, and the crust is commonly complexly reflective/diffractive throughout.
Statistical sampling and regression analysis for RT-level power evaluation

In this paper, we propose a statistical power evaluation framework at the RT-level. We first discuss the power macro-modeling formulation, and then propose a simple random sampling technique to alleviate the the overhead of macro-modeling during RTL simulation. Next, we describe a regression estimator to reduce the error of the macro-modeling approach. Experimental results indicate that the execution time of the simple random sampling combined with power macro-modeling is 50 X lower than that of conventional macro-modeling while the percentage error of regression estimation combined with power macro-modeling is 16 X lower than that of conventional macro-modeling. Hence, we provide the designer with options to either improve the accuracy or the execution time when using power macro-modeling in the context of RTL simulation.
On criteria for dynamic adiabatic shear band propagation

In this work, we postulate the physical criterion for dynamic shear band propagation, and based on this assumption, we implement a numerical algorithm and a computation criterion to simulate initiation and propagation of dynamic adiabatic shear bands (ASBs). The physical criterion is based on the hypothesis that material inside the shear band region undergoes a dynamic recrystallization process during deformation under high temperature and high strain-rate conditions. In addition to providing a new perspective to the physics of the adiabatic shearbanding process and identifying material properties that play a crucial role in defining the material's susceptibility to ASBs, the proposed criterion is instrumental in numerical simulations of the propagation of ASBs when multi-physics models are adopted to describe and predict the complex constitutive behavior of ASBs in ductile materials. Systematic and large scale meshfree simulations have been conducted to test and validate the proposed criterion by examining the formation, propagation, and post-bifurcation behaviors of ASBs in two materials, 4340 steel and OFHC copper. The effects of heat conduction, in particular the length scale introduced by heat conduction, are also studied. The results of the numerical simulations are compared with experimental observations and a close agreement is found for various characteristic features of ASBs, such as the shear band width, speed of propagation, and maximum temperature.
Effect on fatality risk of changing from secondary to primary seat belt enforcement.

Abstract Background: Most seat belt use laws originally passed in the United States contained language restricting enforcement to drivers already stopped for some other reason. States that have since removed this secondary enforcement restriction have reported increased seat belt use. The purpose of the present study was to estimate the effect of these law changes on driver fatality rates. Method: Trends in passenger vehicle driver death rates per billion miles traveled were compared for 10 states that changed from secondary to primary seat belt enforcement and 14 states that remained with secondary enforcement. Results: After accounting for possible economic effects and other general time trends, the change from secondary to primary enforcement was found to reduce annual passenger vehicle driver death rates by an estimated 7% (95% confidence limits 3.0–10.9). Conclusion: The majority of U.S. states still have secondary enforcement laws. If these remaining secondary laws were amended, an estimated 696 deaths per year could be prevented.
Chronicles of obsession: Magazines for the audiophile

The December 1992 issue of Stereophile featured on its cover the magazine's choice for the best product of the year: the Mark Levinson No. 30 Digital Processor. This $15,000 piece of stereo equipment is designed to accept the digital signal from a compact disk or other digital recording medium and convert it to an analog signal that will be amplified and sent out to a pair of loudspeakers. A close examination of the Levinson No. 30 reveals it to be a marvel of state-of-the-art electrical engineering, using parts of such high quality that jealousy might be induced at the Pentagon. The Levinson No. 30, however, is marketed as a consumer product. It stands as an example of how far an audiophile's obsession can extend. The quest to accurately and fully reproduce recorded sound in the home knows no boundaries other than those set by the laws of physics and the size of an audiophile's budget. An audiophile committed to putting together the best stereo system possible can easily spend over $100,000. The components will typically come from manufacturers whose names are completely unfamiliar to those who buy their stereos at local discount stores like Circuit City, Silo, and Best Buy. Manufacturers like Audio Research, Madrigal Audio, Krell, Apogee Acoustics, and Thiel Audio Products sell their wares at high-end audio stores, many of which have the air of specialized boutiques and serve as gathering places for a community's audiophiles. In recent years American manufacturers of high-end stereo equipment have
On the Interaction of Insoluble Spherical Particles with a Solidifying Interface in the Presence of Morphological Instabilities

The interaction of a dilute suspension of spherical particles with a moving solidifying front is investigated analytically. The front emerges during the unidirectional solidification of a dilute binary alloy. A linear stability analysis of the planar interface reveals that the presence of the particles has a destabilizing effect, i.e. the critical value of the control parameter, taken here to be the concentration far away from the interface, for the onset of the Mullins-Sekerba instability is lowered due to the particles` presence.
Determining the Relative Permittivity of Deep Embedded Biological Tissues

This letter introduces a novel in vivo method for determining the dielectric properties of deep human tissues, including lungs. A surgery-free method is proposed for an on-body monitoring system to evaluate the electrical properties of internal body organs and to detect irregularities in real time. The method uses a set of electrodes (16 or 40 MHz in operational frequency) to obtain data that relates the electrical properties of the underlying biological tissue(s) to the measured port scattering parameters. By using multiple electrodes, effects from outer layers (skin, fat, and muscle) can be suppressed, allowing for an accurate characterization of deeper layers. Specifically, the dielectric constant is expressed as a weighted sum of the scattering parameters from each probe. The weights of the scattering coefficients are then determined through a training process to ensure that various changes in the outer layers do not contaminate the extraction of the dielectric constant(s) associated with deeper tissues.
A Two-Dimensional Equivalent Complex Permeability Model for Round-Wire Windings

Eddy currents at high frequencies affect both active power and reactive power in a winding. Recently a two-dimensional (2-D) model for calculating power loss in round-wire windings was introduced and was shown to have higher accuracy than the Dowell model and the Bessel-function method. The model was given in terms of proximity-effect loss normalized by the square of field magnitude and conductivity. In order to find the total proximity-effect loss, the field distribution in the winding window should also be known, which requires the modeling of not only how the eddy currents in windings affect power loss but also how they affect the field distribution in the window. Based on the proximity-effect loss model and the Kramer-Kronig relation, we derive an equivalent complex permeability model of a round-wire winding that agrees with finite element analysis results. This model can be used to calculate high-frequency winding loss and inductances (especially leakage inductance) in transformers and inductors with two-dimensional geometry. Numerical simulation results and experimental results validate the complex permeability model
Do iconic gestures pave the way for children's early verbs?

Children produce a deictic gesture for a particular object (point at dog) approximately 3 months before they produce the verbal label for that object (“dog”; Iverson & Goldin-Meadow, 2005). Gesture thus paves the way for children’s early nouns. We ask here whether the same pattern of gesture preceding and predicting speech holds for iconic gestures. In other words, do gestures that depict actions precede and predict early verbs? We observed spontaneous speech and gestures produced by 40 children (22 girls, 18 boys) from age 14 to 34 months. Children produced their first iconic gestures 6 monthslater than they produced their first verbs. Thus, unlike the onset of deictic gestures, the onset of iconic gestures conveying action meanings followed, rather than preceded, children’s first verbs. However, iconic gestures increased in frequency at the same time as verbs did and, at that time, began to convey meaningsnotyetexpressedinspeech.Ourfindingssuggestthatchildrencanusegesturetoexpandtheir repertoire of action meanings, but only after they have begun to acquire the verb system underlying their language.
Ten questions for evolutionary studies of disease vulnerability

Many evolutionary applications in medicine rely on well-established methods, such as population genetics, phylogenetic analysis, and observing pathogen evolution. Approaches to evolutionary questions about traits that leave bodies vulnerable to disease are less well developed. Strategies for formulating questions and hypotheses remain unsettled, and methods for testing evolutionary hypotheses are unfamiliar to many in medicine. This article uses recent examples to illustrate successful strategies and some common challenges. Ten questions arise in the course of considering hypotheses about traits that leave bodies vulnerable to disease. Addressing them systematically can help minimize confusion and errors.
Effects of Channelization on Sabine Map Turtle Habitat in the Mermentau River Drainage, Louisiana: Use of Original vs. New Channels

Graptemys sabinensis (Sabine Map Turtle) occurs in the Sabine, Calcasieu, and Mermentau river drainages of Louisiana and Texas. The Mermentau River was altered by construction of seven cut-offs between the towns of Mermentau and Lake Arthur, LA, in the 1970s, and several cut-offs also have been constructed along the river's largest tributary, Bayou Plaquemine Brule. We surveyed basking turtles on lower Plaquemine Brule and the Mermentau River to determine if the new channels are used to the same extent as the original channels. The original channels had nonsignificantly higher counts of basking Sabine Map Turtles and total turtles than the new channels. However, the shorter new channels had significantly higher densities of Sabine Map Turtles and total turtles than the original channels. The new channels create a bypass for excess water on the river following heavy rainfall, allowing higher flow on new channels, which may be preferred by Sabine Map Turtles. There was no significant difference in Sabine Map Turtle density between the inner and outer banks of the Mermentau's original channels, presumably because dredging made the depths along the inner and outer banks similar; new channels also divert water away from the original channels during high-flow events, which may maintain the anthropogenically homogenized condition of the original channels.
Fertility preservation for social indications: a cost-based decision analysis.

Objective Age-related infertility remains a problem that assisted reproductive techniques (ART) have limited ability to overcome. Correspondingly, because an increasing number of women are choosing to delay childbearing, fertility preservation strategies, initially intended for patients undergoing gonadotoxic therapies, are being applied to this group of healthy women. Studies supporting the effectiveness of this practice are lacking. Design Decision analytic techniques. Setting We compared the cost-effectiveness of three strategies for women planning delayed childbearing until age 40: oocyte cryopreservation at age 25, ovarian tissue cryopreservation (OTC) at age 25, and no assisted reproduction until spontaneous conception had been attempted. Patient(s) Not applicable. Intervention(s) Not applicable. Main Outcome Measure(s) Cost-effectiveness, which was defined as the cost per live birth. Result(s) In this analysis, the strategy of foregoing fertility preservation at age 25 and then choosing ART only after not spontaneously conceiving at age 40 was the most cost-effective option. OTC was dominated by the other strategies. Sensitivity analyses demonstrated the robustness of the model; no analysis existed in which OTC was not dominated by oocyte cryopreservation. Increasing the cost of an IVF cycle beyond $22,000 was the only situation in which oocyte cryopreservation was the most preferred strategy. Conclusion(s) Neither oocyte cryopreservation nor OTC appear to be cost-effective under current circumstances for otherwise healthy women planning delayed childbearing. This analysis should give pause to the current practice of offering fertility preservation based only on the desire for delayed childbearing.
Generalized view of a Data Base

A Data Base is a large collection of data, usually accessible to many users and organized to optimize the overall operation of the community of users. The format of data is chosen by an administrator, normally referred to as data base administrator. The data representation is — in most cases — standardized to a few types within a system; data are accessed on behalf of a user by a data base manager program. In addition to the data itself, this program also has available descriptive information about the data in the data base. Using this information the data base management program can convert data from the internal representation to any representation requested by the user.