cssi/SciSciGPT-SciSciNet huggingface dataset:
Termination criteria for solving concurrent safety and reachability games

We consider concurrent games played on graphs. At every round of a game, each player simultaneously and independently selects a move; the moves jointly determine the transition to a successor state. Two basic objectives are the safety objective to stay forever in a given set of states, and its dual, the reachability objective to reach a given set of states. We present in this paper a strategy improvement algorithm for computing the value of a concurrent safety game, that is, the maximal probability with which player 1 can enforce the safety objective. The algorithm yields a sequence of player-1 strategies which ensure probabilities of winning that converge monotonically to the value of the safety game.Our result is significant because the strategy improvement algorithm provides, for the first time, a way to approximate the value of a concurrent safety game from below. Since a value iteration algorithm, or a strategy improvement algorithm for reachability games, can be used to approximate the same value from above, the combination of both algorithms yields a method for computing a converging sequence of upper and lower bounds for the values of concurrent reachability and safety games. Previous methods could approximate the values of these games only from one direction, and as no rates of convergence are known, they did not provide a practical way to solve these games.
Some Examples of Tilt-Stable Objects on Threefolds

We investigate properties and describe examples of tilt-stable objects on a smooth complex projective threefold. We give a structure theorem on slope semistable sheaves of vanishing discriminant, and describe certain Chern classes for which every slope semistable sheaf yields a Bridgeland semistable object of maximal phase. Then, we study tilt stability as the polarization ω gets large, and give sufficient conditions for tilt-stability of sheaves of the following two forms: 1) twists of ideal sheaves or 2) torsion-free sheaves whose first Chern class is twice a minimum possible value.
Structured region graphs: morphing EP into GBP

GBP and EP are two successful algorithms for approximate probabilistic inference, which are based on different approximation strategies. An open problem in both algorithms has been how to choose an appropriate approximation structure. We introduce "structured region graphs," a formalism which marries these two strategies, reveals a deep connection between them, and suggests how to choose good approximation structures. In this formalism, each region has an internal structure which defines an exponential family, whose sufficient statistics must be matched by the parent region. Reduction operators on these structures allow conversion between EP and GBP free energies. Thus it is revealed that all EP approximations on discrete variables are special cases of GBP, and conversely that some well-known GBP approximations, such as overlapping squares, are special cases of EP. Furthermore, region graphs derived from EP have a number of good structural properties, including maxent-normality and overall counting number of one. The result is a convenient framework for producing high-quality approximations with a user-adjustable level of complexity.
Measuring Financial Inclusion : The Global Findex Database

This paper provides the first analysis of the Global Financial Inclusion (Global Findex) Database, a new set of indicators that measure how adults in 148 economies save, borrow, make payments, and manage risk. The data show that 50 percent of adults worldwide have an account at a formal financial institution, though account penetration varies widely across regions, income groups and individual characteristics. In addition, 22 percent of adults report having saved at a formal financial institution in the past 12 months, and 9 percent report having taken out a new loan from a bank, credit union or microfinance institution in the past year. Although half of adults around the world remain unbanked, at least 35 percent of them report barriers to account use that might be addressed by public policy. Among the most commonly reported barriers are high cost, physical distance, and lack of proper documentation, though there are significant differences across regions and individual characteristics.
Credit Constraints in the Demand for Education: Evidence from Survey Data

What can subjective reports of financial difficulties add to our understanding about the role of liquidity constraints in the demand for college education? Liquidity constraints in education may lead to inefficient skill allocations and perpetuate imbalances in the distribution of economic well-being. Unfortunately, empirical evidence regarding their pervasiveness in the U.S. has not been consistent in part because constraints tend to be inferred indirectly. To evaluate how a potentially more direct measure can be used to enhance our understanding of the issue, I focus on self-reports of financial difficulties available in the National Longitudinal Survey of Youth. I find that about 12 percent of college-age individuals expect to underinvest in education because of financial limitations, which is an upper-bound estimate of the fraction of liquidity-constrained students. While this paper shows that subjective indicators of credit constraints are potentially noisy, they appear to reveal important aspects of heterogeneity in the demand for education not captured by the standard measures such as, e.g. parental income.
Rebellion on sugarscape: case studies for greed and grievance theory of civil conflicts using agent-based models

Public policy making has direct and indirect impacts on social behaviors. However, using system dynamics model alone to assess these impacts fails to consider the interactions among social elements, thus may produce doubtful conclusions. In this study, we examine the political science theory of greed and grievance in modeling civil conflicts. An agent-based model is built based on an existing rebellion model in Netlogo. The modifications and improvements in our model are elaborated. Several case studies are used to demonstrate the use of our model for investigating emergent phenomena and implications of governmental policies.
Statistics and the Modern Student

Statistics and the Modern Student Robert Gould University of California, Los Angeles rgould@stat.ucla.edu Summary The introductory statistics course has traditionally targeted consumers of statistics with the intent of producing a citizenry capable of a critical analysis of basic published statistics. More recently, statistics educators have attempted to center the intro course on real data, in part to motivate students and in part to create a more relevant course. The success of this approach is predicated on providing data that the students see as real and relevant. Modern students, however, have a different view of data than did students of 10 or even 5 years ago. Modern statistics courses must adjust to the fact that students' first exposure to data occurs outside the academy. Les cours d'initiation a la statistique ont traditionellement vise les consomammateurs de la statistique avec l'intention de produire une population capable de faire une analyse critique des statistiques elementaires publiees. Plus recemment, les professeurs de la statistique ont tente d'orienter les cours d'initiation vers des donnees reelles, afin de motiver les eleves d'un part, et de creer un cours plus pertinent d'autre part. Le succes de cette approche repose sur une provision de donnees que les etudiants considerent comme reels et pertinents. Cependent, les etudiants modernes ont une vision des donnees qui est differente de celle qu'ont eu les eleves d'il y a 10 ou meme 5 ans. Les cours modernes de statistique doivent s'adapter au fait que la premiere rencontre des eleves aux donnees a lieu en dehors de l'academie. Key words: Education; data technology; statistical literacy; technological literacy; data. The time may not be very remote when it will be understood that for a complete initiation as an efficient citizen of one of the new great complex world wide states that are now developing, it is as necessary to be able to compute, to think in averages and maxima and minima, as it is now to be able to read and write. --H.G. Wells (1903, pg 204) 1.0 History and Background of Intro Statistics Perhaps because Wells was best known for his science fiction, the above quote, written in 1904, is often attributed an oracular quality. But Francis Galton and Florence Nightingale were alive in 1904, and so perhaps the quote is better understood as a reflection of the excitement that grew as many realized that statistics was no longer just for astronomers, but useful in the social sciences, medical science, biology, criminology,
Transition metal-catalyzed ketone-directed or mediated C–H functionalization

Transition metal-catalyzed C-H functionalization has evolved into a prominent and indispensable tool in organic synthesis. While nitrogen, phosphorus and sulfur-based functional groups (FGs) are widely employed as effective directing groups (DGs) to control the site-selectivity of C-H activation, the use of common FGs (e.g. ketone, alcohol and amine) as DGs has been continuously pursued. Ketones are an especially attractive choice of DGs and substrates due to their prevalence in various molecules and versatile reactivity as synthetic intermediates. Over the last two decades, transition metal-catalyzed C-H functionalization that is directed or mediated by ketones has experienced vigorous growth. This review summarizes these advancements into three major categories: use of ketone carbonyls as DGs, direct β-functionalization, and α-alkylation/alkenylation with unactivated olefins and alkynes. Each of these subsections is discussed from the perspective of strategic design and reaction discovery.
A Priori v Post Hoc Testing

In many situations, statistical analyses are given more credibility when they are planned prospectively, that is, in advance of the collection of the data. Such prespecified analyses cannot be said to have been suggested by the data, as post hoc analyses would be. A simple measure to prevent the difficult interpretation that can arise from post hoc analyses is to simply avoid them. This approach may be overly conservative, however, as the need may arise to test a hypothesis that the data suggested, and use the same data to test it. Several approaches exist for doing so, although not all of them have been cast as tests of post hoc analyses. In the analysis of variance framework, Fisher's least significant difference (LSD) and Scheffe's method can both be viewed as a means of performing post hoc linear comparisons, although they may not always be explicitly referred to as post hoc analyses. The Smirnov test may be viewed as a method to allow for the data to select the cut point of an ordinal outcome measure. Certain adaptive tests for ordinal data may be viewed as taking the Smirnov test to the next level, and allowing for the optimal combination of cut points, based on the data. The information-preserving composite end point is a method to allow for data-dependent outcome measure selection. Keywords: adaptive tests; alpha allocation; fisher protected LSD; inherent multiplicity; information-preserving composite end points
Migration of matter from the Edgeworth-Kuiper and main asteroid belts to the Earth

A considerable proportion of near-Earth objects could come from the trans-Neptunianbelt. Some of them have aphelia deep inside Jupiter's orbit for >1 Myr.
The effect of biodiesel policies on world oilseed markets and developing countries

Using an empirical model, this study provides some insights into the functioning of the oilseed-biodiesel-diesel market complex in a large country that determines the biodiesel price, reflecting market equilibrium changes resulting from volatility in the crude oil price. Oilseed crushing produces joint products -- oil and meal -- and this weakens the link between the biodiesel and oilseed feedstock prices. Higher crude oil prices increase biodiesel prices if biofuel benefits from a fuel tax exemption, but lower them with a blending mandate (minimum biofuel content requirement in marketed fuel). When both canola and soybeans are used to produce biodiesel, an increase in the crude oil price leads to higher canola prices, but the effect on soybean prices is ambiguous and depends on relative elasticities of meal demand and canola supply because canola produces more oil than soybeans. An oil price shock with a blending mandate results in a smaller change in oilseed prices compared with a fuel tax exemption. Jumps in world crude oil prices have differential impacts on commodity prices and welfare in developing countries, depending on which policy determines the biodiesel price in OECD countries.
Recognizing Uncertainty in Speech

We address the problem of inferring a speaker's level of certainty based on prosodic information in the speech signal, which has application in speech-based dialogue systems. We show that using phrase-level prosodic features centered around the phrases causing uncertainty, in addition to utterance-level prosodic features, improves our model's level of certainty classification. In addition, our models can be used to predict which phrase a person is uncertain about. These results rely on a novel method for eliciting utterances of varying levels of certainty that allows us to compare the utility of contextually-based feature sets. We elicit level of certainty ratings from both the speakers themselves and a panel of listeners, finding that there is often a mismatch between speakers' internal states and their perceived states, and highlighting the importance of this distinction.
Parallel multilevel graph partitioning

In this paper we present a parallel formulation of a graph partitioning and sparse matrix ordering algorithm that is based an a multilevel algorithm we developed recently. Our parallel algorithm achieves a speedup of up to 56 on a 128-processor Cray T3D for moderate size problems, further reducing its already moderate serial run-time. Graphs with over 200,000 vertices can be partitioned in 128 parts, on a 128-processor Gray T3D in less than 3 seconds. This is at least an order of magnitude better than any previously reported run times on 128-processors for obtaining an 128-partition. This also makes it possible to use our parallel graph partitioning algorithm to partition meshes dynamically in adaptive computations. Furthermore, the quality of the produced partitions and orderings are comparable to those produced by the serial multilevel algorithm that has been shown to substantially outperform both spectral partitioning and multiple minimum degree.
Characterization of an Extracellular Dextranase from Fusarium moniliforme

Abstract An extracellular dextranase (EC 3.2.1.11) was purified approximately 75-fold from cell-free culture filtrates of Fusarium moniliforme. The purified dextranase was of the endo type, and isomaltose was identified as the primary end product of dextran hydrolysis. The molecular weight of the dextranase was determined to be 39,000 by gel permeation chromatography. The enzyme was most active at pH 5.5, and the temperature optimum was near 55 C. Activity was not inhibited by either ethylenediaminetetraacetic acid or iodoacetate. The Km for dextran with an average molecular weight of 10,000 was estimated to be 1.1 × 10-4 M. The electrophoretic mobility of the dextranase was distinctly different from that of a Penicillium-derived commercial dextranase. The F. moniliforme dextranase was also found to differ from the commercial preparation by its greater relative activity against glucans isolated from Streptococcus mutans.
Performability modeling with UltraSAN

Stochastic extensions to Petri nets have received growing attention during the past decade as a model for evaluating the performance, dependability, and performability of computer hardware, software, and networks. Their formal structure permits solution by analytic means in many cases. When this is not possible, they an facilitate the automatic generation of a simulation program to estimate system behavior. The paper describes an X-window based software tool for evaluating systems that are represented as stochastic activity networks, a variant of stochastic Petri nets. The tool, known as UltraSAN, incorporates the results of recent research to significantly reduce the size of the state space that is considered for analytic solution, as well as the number of event types that are considered in simulation. Throughout the paper, a simple local area network model is used to illustrate the concepts, user interface, and model construction and solution methods implemented in the package. >
Balancing the baryon budget: the fraction of the IGM due to galaxy mergers

Observations indicate that roughly 60 per cent of the baryons may exist in a warm-hot intergalactic medium (WHIM) at low redshifts. Following up on previous results showing that gas is released through galaxy mergers, we use a semi-analytic technique to estimate the fraction of gas mass lost from haloes solely due to mergers. We find that up to ∼25 per cent of the gas in a halo can unbind over the course of galaxy assembly. This process does not act preferentially on smaller mass haloes; bigger haloes always release larger amounts of gas in a given volume of the Universe. However, if we include multiphase gas accretion on to haloes, we find that only a few per cent is unbound. We conclude that either non-gravitational processes may be in play to heat up the gas in the galaxies prior to unbinding by mergers or most of the baryons in the WHIM have never fallen into virialized dark matter haloes. We present a budget for stocking the WHIM compiled from recent work.
Synthesis of alkenyl- and alkynylcyclopropenes

Abstract Fluoride anion promoted dehalosilation of 2-(chlorocyclopropyl)trimethylsilanes in the gas-phase was used to prepare a variety of monosubstituted cyclopropenes containing additional unsaturations. The cyclopropylsilanes were constructed easily from common intermediates.
CT Saturation in Industrial Applications - Analysis and Application Guidelines

This paper analyzes the problem of protection class CTs in detail and explains its underlying mechanics. Several actual relays are analyzed in terms of their response to heavily saturated waveforms. A formal, compact and easy to grasp method is shown to present complex relations between the CT response and the response of any given relay. Based on this graphical method one can quickly evaluate the problem and clearly see an alternative solution if a problem truly exists. This exploratory analysis shows that severely saturated CTs only slightly reduce short circuit tripping capabilities of existing relays. Given the typically applied settings, there is no danger of a failure to trip from instantaneous overcurrent functions even in extreme cases of very high short-circuit currents and low-ratio CTs
Far-reaching transient motions after Mojave earthquakes require broad mantle flow beneath a strong crust

[1] Geodeticallyobservedpostseismicsurfacedisplacements in the 7 years following the 1999 Hector Mine earthquake demonstrate a previously unrecognized broad pattern of transient deformation throughout southern California and into Nevada, more than 200 km from the epicenter. Unlike previous postseismic observations in which trade-offs between postseismic mechanisms and the depth of flow lead to non-unique solutions, this deformation pattern can only be explained by viscoelastic flow in a region of the mantle 100s of km wide and below a depth of 40 km. This result enables two robust conclusions regarding the nature of lithospheric strength in this region: the mantle is weaker than the lower crust, and flow occurs over a wide region of mantle as opposed to within a narrow shear zone beneath
Maternal High-Fat Diet Disturbs Uteroplacental Hemodynamics and Increases the Frequency of Stillbirth in a Nonhuman Primate Model of Excess Nutrition

Prepregnancy maternal obesity confers an increased risk of stillbirth, but the mechanisms are unknown. Maternal obesity is associated with placental inflammation. We considered that maternal diet may predispose to the increased risk of placental inflammation and stillbirth. We hypothesized that a chronic high-fat diet (HFD) is associated with abnormal uteroplacental circulation and placental inflammation. Here we used a nonhuman primate model to determine the effect of chronic HFD on the uterine and placental hemodynamics, placental histology, and inflammation in a prospective, observational study of 24 Japanese macaques. Overall, there was a statistically significant (38-56%) reduction in uterine volume blood flow from HFD animals, whether they were lean or obese. Consumption of a HFD, independent of obesity, increased placental inflammatory cytokines and the expression of Toll-like receptor 4. We show that HFD consumption by obese mothers with hyperinsulinemia also reduced volume blood flow on the fetal side of the placenta and significantly increased the frequency of both placental infarctions and stillbirth. These results suggest that a HFD, independent of obesity, decreases uterine volume blood flow. Maternal obesity and insulin resistance further exacerbates the placental dysfunction and results in an increased frequency of stillbirth.
Pregnancy outcome following cancer chemotherapy

The outcome of pregnancies of patients who received aggressive chemotherapy was examined. Of 448 patients screened, 30 had 12 abortions (10 elective and two spontaneous) and 28 live births. Follow-up of off spring revealed no major malformations. In addition, growth, development and school performance were normal. These results support the contention that chemotherapy administered to women prior to gestation or after the first trimester may result in normal births in the majority of cases. Moreover, the available data suggest that chemotherapy given to men at or prior to the time of conception does not appear to result in fetal damage. These results may be of value in counseling cancer patients regarding risks to their offspring.
Far-Infrared gaps in single-wall carbon nanotubes

Reflectance of single-wall carbon nanotubes (SWNTs) has been measured over 15-30000 cm-1 (2-3720 meV). The sample is a free-standing film composed of purified SWNTs. The temperature dependence of the reflectance is quite small at all temperatures studied (7.8 K to 298 K) and no vibrational features are observed. The spectra have a Drude-like dispersion, the reflectance monotonically decreasing as photon energy increases, with a plasma edge around 2500 cm-1 (310 meV). The dispersion is analyzed by a Drude model combined with a low-frequency localized band. The optical conductivity derived from a Kramers-Kronig analysis shows a strong peak at 135 cm-1 (17 meV), which corresponds to the Lorentzian absorption in the dispersion analysis. This far-infrared band is assigned to a pseudogap in metallic armchair nanotubes and/or to small-gaps in zigzag or chiral nanotubes. The sum-rule calculation indicates that the one third of SWNTs in our sample belongs to the class of metallic or small-gap SWNTs. The lineshape ...
Magnesium nitride chemistry

Abstract Experiments in the system RE–Mg–N (RE=La, Ce, Gd) have been done to explore the possible synthesis of nitrides using Mg as reactive melt and to extend the number of known nitride compounds containing Mg. Since these experiments produce only binary nitrides, we explored the use of mixed Na/Mg melts and discovered the quarternary nitrides BaMg 3.33 Nb 0.67 N 4 ( 1 ), BaMg 3.33 Ta 0.67 N 4 ( 2 ) and Eu 4 TaMgN 5 ( 3 ), which were characterized by single crystal structure analysis. The BaMg 3.33 M 0.67 N 4 compounds are isotypic to UCr 4 C 4 [R.K. Behrens, W. Jeitschko, Monatsh. Chem. 118 (1987) 43–50] (filled MoNi 4 type [D. Harker, J. Chem. Phys. 12 (1944) 315–317]) and crystallize in the space group I 4/ m (#87) with the lattice parameters a =856.40(12) and c =353.90(7) pm for ( 1 ), and a =859.61(8) and c =354.21(5) for ( 2 ). ( 3 ) crystallizes in a new structure type in the acentric orthorhombic space group Pna 2 1 (#33) with the lattice parameters a =1265.5(3), b =1015.9(2) and c =692.5(1) pm.
Measurement of Structural Changes in Tetragonal PZT Ceramics under Static and Cyclic Electric Fields Using a Laboratory X-ray Diffractometer

In situ structural characterization techniques that are capable of characterizing piezoelectric ceramics under different electrical loading conditions are important to understand the behavior of materials during their use. In this work, we report the use of a laboratory X-ray diffractometer for the measurement of various structural changes in tetragonal La-doped lead zirconate titanate (PZT) ceramics under the application of static and cyclic electric fields. The changes in the volume fractions of the 90deg domains parallel to the electric field direction are calculated from the intensities of the {002} diffraction peaks. In addition, the components of lattice strains are monitored from the changes in the (111) crystallographic planes. It is observed that, under the application of static electric fields, both 90deg domain switching and the 111 lattice strains showed similarity with the macroscopic strain-electric field hystersis loop. To measure the structural changes under cyclic electric fields, a time-resolved X-ray diffraction technique was used. Under application of a square-wave electric field of amplitude plusmn650 V/mm and frequency 0.3 Hz, a change of ~5% in the volume fraction of the 90deg domains and ~0.07% strain of the 111 lattice planes are observed. Both the amount of 90deg domain switching and the 111 lattice strains are observed to increase with an increase in the amplitude of the cyclic electric field. The implications of the measured structural changes for the macroscopic piezoelectric properties of ceramics are discussed.
Sample spaces with small bias on neighborhoods and error-correcting communication protocols

We give a deterministic algorithm which, on input an integer n , collection \cal F of subsets of {1,2,\ldots,n} , and ɛ∈ (0,1) , runs in time polynomial in n| \cal F |/ɛ and produces a \pm 1 -matrix M with n columns and m=O(log | \cal F |/ɛ 2 ) rows with the following property: for any subset F ∈ \cal F , the fraction of 1's in the n -vector obtained by coordinatewise multiplication of the column vectors indexed by F is between (1-ɛ)/2 and (1+ɛ)/2 . In the case that \cal F is the set of all subsets of size at most k , k constant, this gives a polynomial time construction for a k -wise ɛ -biased sample space of size O(log n/ɛ 2 ) , compared with the best previous constructions in [NN] and [AGHP] which were, respectively, O(log n/ɛ 4 ) and O(log 2 n/ɛ 2 ) . The number of rows in the construction matches the upper bound given by the probabilistic existence argument. Such constructions are of interest for derandomizing algorithms. As an application, we present a family of essentially optimal deterministic communication protocols for the problem of checking the consistency of two files.
The Integration of Mortgage and Capital Markets in Emerging Economies—Evidence from South Africa

Integration of the capital and mortgage markets is an important step in moving emerging countries toward full economic development. With data from South Africa, this research examines the incremental contribution of deregulation and the secondary mortgage market to the integration between the mortgage and capital markets. With deregulation occurring in the early 1980s, the results indicate that the two markets were fully integrated prior to 2001 when a secondary mortgage market was introduced in South Africa. However, we also find that the introduction of the secondary mortgage market has significantly reduced constraints on the supply of mortgage credit.
A Unique and Highly Efficient Method for Catalytic Olefin Aziridination

A facile, high yielding, and stereospecific method for olefin aziridination is described. This process capitalizes on the unique reactivity of sulfamate esters in combination with 1-2 mol % Rh2(tfacam)4 and PhI(OAc)2 as the terminal oxidant to promote N-atom transfer reactions. A range of structurally and electronically disparate alkenes are found to react under conditions that employ substrate as the limiting reagent and only a slight excess of H2NSO3CH2CCl3 as the nitrogen source. The product alkoxysulfonyl aziridines are useful intermediates that react smoothly with nucleophiles to generate 1,2-amine derivatives. Following aziridine ring-opening, the N-trichloroethoxysulfonyl group can be removed under mild reductive conditions (Zn(Cu)/AcOH-MeOH) to give the corresponding 1 degrees amine. The efficient and convenient performance of this chemistry should establish it as a useful tool for synthesis.
The performance of a high speed pipelined photomultiplier readout system in the Fermilab KTeV experiment

Abstract The KTeV fixed target experiment at Fermilab is using an innovative scheme for reading out its 3100 channel CsI electromagnetic calorimeter. This pipelined readout system digitizes photomultiplier tube (PMT) signals over a 16-bit dynamic range with 8-bits of resolution at 53 MHz. The crucial element of the system is a custom Bi-CMOS integrated circuit which, in conjunction with an 8-bit Flash ADC, integrates and digitizes the PMT signal charge over each 18.9 ns clock cycle (53 MHz) in a deadtimeless fashion. The digitizer circuit is local to the PMT base, and has an in-situ charge integration noise figure of 3 fC/sample. In this article, the readout system will be described and its performance including noise, cross-talk, linearity, stability, and reliability will be discussed.
The Rho-GEF Kalirin regulates bone mass and the function of osteoblasts and osteoclasts

Bone homeostasis is maintained by the balance between bone resorption by osteoclasts and bone formation by osteoblasts. Dysregulation in the activity of the bone cells can lead to osteoporosis, a disease characterized by low bone mass and an increase in bone fragility and risk of fracture. Kalirin is a novel GTP-exchange factor protein that has been shown to play a role in cytoskeletal remodeling and dendritic spine formation in neurons. We examined Kalirin expression in skeletal tissue and found that it was expressed in osteoclasts and osteoblasts. Furthermore, micro-CT analyses of the distal femur of global Kalirin knockout (Kal-KO) mice revealed significantly reduced trabecular and cortical bone parameters in Kal-KO mice, compared to WT mice, with significantly reduced bone mass in 8, 14 and 36 week-old female Kal-KO mice. Male mice also exhibited a decrease in bone parameters but not to the level seen in female mice. Histomorphometric analyses also revealed decreased bone formation rate in 14 week-old female Kal-KO mice, as well as decreased osteoblast number/bone surface and increased osteoclast surface/bone surface. Consistent with our in vivo findings, the bone resorbing activity and differentiation of Kal-KO osteoclasts was increased in vitro. Although alkaline phosphatase activity by Kal-KO osteoblasts was increased in vitro, Kal-KO osteoblasts showed decreased mineralizing activity, as well as decreased secretion of OPG, which was inversely correlated with ERK activity. Taken together, our findings suggest that deletion of Kalirin directly affects osteoclast and osteoblast activity, leading to decreased OPG secretion by osteoblasts which is likely to alter the RANKL/OPG ratio and promote osteoclastogenesis. Therefore, Kalirin may play a role in paracrine and/or endocrine signaling events that control skeletal bone remodeling and the maintenance of bone mass.
On the Structure of the Fusion Ideal

We prove that there is a finite level-independent bound on the number of relations defining the fusion ring of positive energy representations of the loop group of a simple, simply connected Lie group. As an illustration, we compute the fusion ring of G 2 at all levels.
A highly efficient asymmetric synthesis of methoxyhomophenylalanine using michael addition of phenethylamine

Abstract A practical method for (S)-p -methoxyhomophenylalanine ( S )- 1 by using diastereoselective Michael addition as a key step was reported. Thus, the Michael addition of ( S )- 1 -phenethylamine ( S )- 3 to p -methoxy- trans -benzoylacrylic acid 2 was performed in a highly stereoselective (up to 98% d.e. and up to 90% yield) fashion and, subsequently, the resultant adduct 4a was catalytically hydrogenated to afford ( S )- 1 almost quantitatively. The most likely mechanism of the addition reaction was dynamic resolution.
Visual and proprioceptive representations in spatial memory

It has been shown that spatial information can be acquired from both visual and nonvisual modalities. The present study explored how spatial information from vision and proprioception was represented in memory, investigating orientation dependence of spatial memories acquired through visual and proprioceptive spatial learning. Experiment 1 examined whether visual learning alone and proprioceptive learning alone yielded orientation-dependent spatial memory. Results showed that spatial memories from both types of learning were orientation dependent. Experiment 2 explored how different orientations of the same environment were represented when they were learned visually and proprioceptively. Results showed that both visually and proprioceptively learned orientations were represented in spatial memory, suggesting that participants established two different reference systems based on each type of learning experience and interpreted the environment in terms of these two reference systems. The results provide some initial clues to how different modalities make unique contributions to spatial representations.
MODELING GAMMA-RAY BURST X-RAY FLARES WITHIN THE INTERNAL SHOCK MODEL

X-ray afterglow light curves have been collected for over 400 Swift gamma-ray bursts (GRBs) with nearly half of them having X-ray flares superimposed on the regular afterglow decay. Evidence suggests that gamma-ray prompt emission and X-ray flares share a common origin and that at least some flares can only be explained by long-lasting central engine activity. We have developed a shell model code to address the question of how X-ray flares are produced within the framework of the internal shock model. The shell model creates randomized GRB explosions from a central engine with multiple shells and follows those shells as they collide, merge, and spread, producing prompt emission and X-ray flares. We pay special attention to the time history of central engine activity, internal shocks, and observed flares, but do not calculate the shock dynamics and radiation processes in detail. Using the empirical E{sub p} -E{sub iso} (Amati) relation with an assumed Band function spectrum for each collision and an empirical flare temporal profile, we calculate the gamma-ray (Swift/BAT band) and X-ray (Swift/XRT band) lightcurves for arbitrary central engine activity and compare the model results with the observational data. We show that the observed X-ray flare phenomenology can be explainedmore » within the internal shock model. The number, width, and occurring time of flares are then used to diagnose the central engine activity, putting constraints on the energy, ejection time, width, and number of ejected shells. We find that the observed X-ray flare time history generally reflects the time history of the central engine, which reactivates multiple times after the prompt emission phase with progressively reduced energy. The same shell model predicts an external shock X-ray afterglow component, which has a shallow decay phase due to the initial pile-up of shells onto the blast wave. However, the predicted X-ray afterglow is too bright as compared with the observed flux level, unless epsilon{sub e} is as low as 10{sup -3}.« less
Triaxial Test Simulations with Discrete Element Method and Hydrostatic Boundaries

A new boundary condition has been developed for the discrete element method. This boundary is different from the conventional periodic, rigid, or flexible boundries. This new boundary mechanism was developed to simulate triaxial tests. The new boundary, hydrostatic boundary, simulated the chamber fluid but not the rubber membrane. When a particle (ellipsoids in our simulations) contacts the hydrostatic boundary, pressure is developed. The interaction between the particle and the boundary is calculated analytically based on geometry. This hydrostatic boundary condition was implemented into an existing ellipsoidal discrete element code. Triaxial compression drained tests were performed with both periodic and hydrostatic boundaries. The result showed an increase in friction angle over the values observed from the periodic boundary mechanism. The result also closely resembles the experimental triaxial data. Thirteen specimens were generated and were used to investigate the following variables: particle shape, specimen size, and void ratio. A unique slope of the linear relationship between friction angle and void ratio was identified for monosize specimens of different particle shapes. It is found that the friction angle decreases as the aspect ratio increases provided that the void ratio of the two specimens is the same. The friction angle is linear proportional to the coordination number for monosize specimens regardless the specimen size. Also, the specimen size does not influence the behavior of two-size specimens.
Heavy traffic optimal resource allocation algorithms for cloud computing clusters

Cloud computing is emerging as an important platform for business, personal and mobile computing applications. In this paper, we study a stochastic model of cloud computing, where jobs arrive according to a stochastic process and request resources like CPU, memory and storage space. We consider a model where the resource allocation problem can be separated into a routing or load balancing problem and a scheduling problem. We study the join-the-shortest-queue routing and power-of-two-choices routing algorithms with the MaxWeight scheduling algorithm. It was known that these algorithms are throughput optimal. In this paper, we show that these algorithms are queue length optimal in the heavy traffic limit.
Recovering Velocity Distributions Via Penalized Likelihood

Line-of-sight velocity distributions are crucial for unravelling the dynamics of hot stellar systems. We present a new formalism based on penalized likelihood for deriving such distributions from kinematical data, and evaluate the performance of two algorithms that extract N(V ) from absorption-line spectra and from sets of individual velocities. Both algorithms are superior to existing ones in that the solutions are nearly unbiased even when the data are so poor that a great deal of smoothing is required. In addition, the discrete-velocity algorithm is able to remove a known distribution of measurement errors from the estimate of N(V ). The formalism is used to recover the velocity distribution of stars in five fields near the center of the globular cluster ω Centauri.
Carbonaceous Chondritic Material in the Solar System

Carbonaceous chondritic matrix material (CCMM) appears to be an important planet-forming unit in the mid-solar system, from the orbits of Mars to that of Uranus. The type specimen for CCMM is the low-temperature (400-500 K) assemblage of clay minerals, organic polymer, magnetite, and Ni-rich iron sulfides which constitutes the black, fine-grained matrix of primitive carbonaceous chondrites. Solar-system objects which appear to be partly or wholly made of CCMM are the satellites of Mars, most asteroids, interplanetary dust, and, perhaps, comets, satellites of the outer planets and the rings of Uranus. CCMM constituents probably formed by low-temperature reactions of higher-temperature condensates with the ambient solar composition gas, or in the case of the organic polymer, by reactions of gaseous species catalyzed by solids.
The Everyday's Fabulous Beyond: Nonsense, Parable, and the Ethics of the Literary in Kafka and Wittgenstein

many complain that the words of the wise, time and again, are only parables, but inapplicable to daily life, which is all we have. When the wise man says, “Cross over,” he does not mean that one should cross over to the other side, which one could still manage, after all, if the result of going that way made it worth it; he means some sort of fabulous Beyond, something we do not know, which he cannot designate more precisely either, and which therefore cannot help us here at all. all these parables really intend to say is only that the incomprehensible is incomprehensible, and that we knew already. But all that we have to struggle with everyday: that is a different matter. Thereupon someone said: Why all this resistance? If you followed parables, you would become parables yourselves and with that free of your daily cares. another said: “I bet that is also a parable.” The first said: “You have won.” The second said: “But unfortunately only in parable.” The first said: “no, in reality; in parable you have lost.” —Franz Kafka, “On parables”1
Coherent Fiber Optics Test Techniques

We have found that reliance on theoretical models or incomplete manufacturer's data is not adequate for predicting the result of combining optical and electro-optical components into a system. The complete imaging characteristics of each component must be accurately known if reliable predictions are expected. Inhouse testing then is desirable where possible. Some components have well-established evaluation procedures. Others, such as coherent fiber optics, require various test techniques, some well established; others must be devised if complete characterization is needed. This is especially true where changes in magnification are a feature of the bundle. A description of the techniques we use for testing the modulation transfer function, image rotation, magnification, image size variation, distortion, shear, transmission efficiency, transmission variation, transmission defects, flatness, and acceptance angle are included in this paper.
Control of the radial motion of a self-propelled microboat through a side rudder

Abstract Similar to macroboats, microboats can be potentially employed to transport a target from one place to another in a small area for the purposes of delivery and detection. In previous work, we developed a type of self-propelled microboat which is capable of having straight motion at speeds of order 0.1 m/s. In this work, using a combination of theoretical, numerical and experimental investigations, we explored another type of self-propelled microboat that could have radial motions. This type of microboat has side rudders. The side rudder induced an additional drag on one side, creating a moment to set the boat into an approximately circular motion. The radii of this motion could be controlled by varying the length of the side rudder. In this work, we designed, fabricated and tested eight microboats, whose rudders ranged from 0 to 10 mm in length. The speeds of these microboats were also in the order of 0.1 m/s. Depending on the rudder lengths, their moving paths had radii varying from infinity to 20 mm. According to moving trajectories, the radius of motion and the travel distance both decreased with the increase in the rudder length. We further built a theoretical model to predict the radius of the first loop of the moving path. By comparing experimental results with numerical solutions to the theoretical model, we found: (i) the numerical results had reasonably good agreement with the experimental results, and (ii) the mismatch between numerical and experimental results increased with an increase in the rudder length due to the simplified consideration in the simulation.
DILUTE BOSE-EINSTEIN CONDENSATE IN A TRAP: CHARACTERISTIC LENGTHS AND CRITICAL VELOCITIES

The Bogoliubov approximation and the Gross-Pitaevskii equation characterize the effect of repulsive interactions on a dilute ideal Bose-Einstein gas in a spherical harmonic trap. For large N, the interactions expand the condensate relative to an ideal Bose gas; both the speed of sound and critical angular velocity Ωc1 for creation of a quantized vortex depend crucially on the interparticle repulsion through the coherence length ξ.
Seasonal albedo of an urban/rural landscape from satellite observations

Using data from 27 calibrated Landsat observations of the Hartford, Connecticut area, the spatial distribution and seasonal variation of surface reflectance and albedo were examined. Mean values of visible reflectance, near-IR reflectance, and albedo are presented (for both snow-free and snow-cover observations) according to 14 land use/land cover categories. A diversity of albedo values was found to exist in this type of environment, associated with land cover. Many land-cover categories display a seasonal dependence, with intracategory seasonal differences being of comparable magnitude to intercategory differences. Key factors in determining albedo (and its seasonal dynamics) are the presence or absence of vegetation and the canopy structure. Snow-cover/snow-free differences range from a few percent (for urban land covers) to over 40 percent (for low-canopy vegetation).
Near infrared (NIR) imaging techniques using lasers and nonlinear crystal optical parametric oscillator/amplifier (OPO/OPA) imaging and transferred electron (TE) photocathode image intensifiers

Laboratory experiments utilizing different near-infrared (NIR) sensitive imaging techniques for LADAR range gated imaging at eye-safe wavelengths are presented. An OPO/OPA configuration incorporating a nonlinear crystal for wavelength conversion of 1.56 micron probe or broadcast laser light to 807 nm light by utilizing a second pump laser at 532 nm for gating and gain, was evaluated for sensitivity, resolution, and general image quality. These data are presented with similar test results obtained from an image intensifier based upon a transferred electron (TE) photocathode with high quantum efficiency (QE) in the 1-2 micron range, with a P-20 phosphor output screen. Data presented include range-gated imaging performance in a cloud chamber with varying optical attentuation of laser reflectance images.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Randomized algorithms and pseudorandom numbers

Randomized algorithms are analyzed as if unlimited amounts of perfect randomness were available, while pseudorandom number generation is usually studied from the perspective of cryptographic security. Bach recently proposed studying the interaction between pseudorandom number generators and randomized algorithms. We follow Bach's lead; we assume that a (small) random seed is available to start up a simple pseudorandom number generator which is then used for the randomized algorithm. We study randomized algorithms for (1) sorting; (2) selection; and (3) oblivious routing in networks.