cssi/SciSciGPT-SciSciNet huggingface dataset:
How Should We Harvest an Animal that Can Live for Centuries

AbstractThe ocean quahog Arctica islandica is an extremely long-lived and slow-growing marine bivalve that supports fisheries in several countries bordering the northern Atlantic ocean. The life history of the ocean quahog presents several unique challenges to fishery managers. Scientists currently have a poor understanding of recruitment and how it might respond to declining population biomass due to fishing pressure, in part because most fisheries have operated for less than one ocean quahog generation. It is therefore difficult to develop management quantities, such as biological reference points, by using traditional means. This simulation study examines ocean quahog recruitment dynamics and explores the implications of a suite of fishing intensities and biomass reference points. Results support the following recommendations: (1) ocean quahog fisheries should be prosecuted with very low fishing mortality rates (F), as Ftarget values greater than 0.03 tended to result in fishery closures while not havi...
Student Perceptions of Various E-Learning Components

Learning that is facilitated by electronic technologies, otherwise known as e-Learning, can be either fully online, mixed mode (also known as hybrid), or web assisted; however, regardless of the delivery method, there are numerous tools and features at the disposal of students and instructors, and it is important for the e-learning community to examine both preferences and usage of these features. This paper presents the findings of a comprehensive study that examined the elearning perceptions and preferences of students enrolled at a historically black university. During this study a series of courses were specially designed to be intensive hybrid learning experiences. The Blackboard CE 6 Course Management System was adopted and paper-less learning experiences created. The results of the analysis indicate that students find course Websites to be helpful resources that enhance the understanding of course content, and that these Websites will continue to have an impact on higher education in the future. The examination of individual e-learning components indicated that students responded favorably to most available features. The strongest preference noted in this study was towards the online submission of assignments, with students overwhelmingly noting that they like having the ability to check their assignment grades online.
Revolutionary Lawyering: Addressing the Root Causes of Poverty and Wealth

It is true that lawyers are rarely revolutionaries. In fact, the idea may seem like an oxymoron (like corporate ethics), but some people are, and others can be, revolutionary lawyers. Our profession is, at the core of its practice, the primary profession world-wide that protects and defends the machines, computers, profit motives and property rights so rightly condemned by Dr. King. We use our training, wealth, and position in society to facilitate commerce without conscience, to accumulate wealth without responsibility, and to serve the needs of corporations over and above the rights and needs of people. Yet still, some lawyers can be revolutionaries. Part I of this Article highlights some of the most glaring details about poverty, wealth and the working poor and provides some facts about racism, materialism and militarism, both nationally and internationally. The briefest look at who is rich and who is poor, and the reasons behind such status, demonstrates the continued accuracy of Dr. King’s prophetic description of why a radical revolution of values is needed, now even more than when he first spoke these words. Part II of this Article discusses some areas of the law that need radical change, law that needs to be torn up by its roots and replaced. Part III reflects on how lawyers who want to be revolutionaries can do so. The Article concludes with signs of hope and a charge to lawyers to consider joining the radical revolution of Dr. King.
Convergence depths of tectonic regions from an ensemble of global tomographic models

[1] We project 3-D variations in shear wave (vS) velocity from 21 whole-mantle tomographic models onto global tectonic regionalizations. The vS profiles of oceanic and continental regions show strong upper mantle variations, as expected from plate tectonics, and most are consistent with lower mantle heterogeneity uncorrelated with surface tectonics. We construct probabilistic lower bounds for a set of convergence depths z^X-Y, where the vS profiles for regions X and Y become statistically indistinguishable. The lower bounds account for intraregional variances and are corrected for vertical-smearing bias. Ensemble probability curves yield z^A-B > 146 km and z^C-B > 178 km at 90% confidence, where A, B, and C comprise oceanic crust of ages 100 Ma. These intra-oceanic convergence depths are consistent with half-space cooling models, showing that the mantle more than 100 km below the G discontinuity participates in conductive cooling, and they imply that the upper part of the oceanic asthenosphere is advected by the plate flow. At 95% confidence, z^PS-BC > 350 km, where region PS comprises stable continents (platforms P and shields S) and BC comprises mature ocean basins (>25 Ma). Stable-continent heterogeneities show high radial correlation, indicating that z^PS-BC marks the base of a coherent tectosphere. Our results call into question the interpretation of the lithosphere-asthenosphere boundary as the kinematic base of the tectonic plates. They are more consistent with a thicker tectosphere decoupled from mantle flow by a low-viscosity layer immediately above the 410 km discontinuity.
Estudios visuales e imaginación global

?Por que los estudios visuales son hoy en dia el foco de nuestra atencion? ?Quien se beneficia de ellos? ?Es acaso esta interrogacion tan solo una respuesta a las nuevas realidades de la cultura global, o acaso este cuestionamiento produce la cultura, y puede entonces producirla de manera critica? Al pensar globalmente, pero desde una posicion particular, “local”, de la historia del arte y por medio de la imagen visual, emerge una estetica muy diferenciada, una ciencia de lo sensible que en nuestra epoca acepta la fina membrana de las imagenes como la manera en que la globalizacion es ineludiblemente percibida. ?Como puede la teoria aprender de las practicas artisticas contemporaneas centradas en estirar esa membrana, proveyendo una profundidad de campo, aletargando el tempo de la percepcion y permitiendo que las imagenes se expongan al espacio de la accion politica comun? ?Que quiere decir algo como “opinion publica” en el contexto de las imagenes globales? ?Cuales son las implicaciones de esto para unos estudios visuales que resisten las inequidades al ir a contrapelo de la imaginacion global? ?Pueden acaso los estudios visuales entrar en un campo de negociacion en pro de una retirada de la hegemonia europea hacia la construccion de una esfera publica globalmente democratica?
Slowly divergent geodesics in moduli space

Slowly divergent Teichmuller geodesics in the moduli space of Riemann surfaces of genus g > 2 are constructed via cyclic branched covers of the torus. Nonergodic examples (i.e. geodesics whose defining quadratic dif- ferential has nonergodic vertical foliation) diverging to infinity at sublinear rates are constructed using a Diophantine condition. Examples with an arbitrarily slow prescribed rate of divergence are also exhibited.
Matching-Vector Families and LDCs over Large Modulo

We prove new upper bounds on the size of families of vectors in \({\mathbb Z}_m^n\) with restricted modular inner products, when m is a large integer. More formally, if \(\vec{u}_1,\ldots,\vec{u}_t \in{\mathbb Z}_m^n\) and \(\vec{v}_1,\ldots,\vec{v}_t \in{\mathbb Z}_m^n\) satisfy \(\langle\vec{u}_i,\vec{v}_i\rangle\equiv0\pmod m\) and \(\langle\vec{u}_i,\vec{v}_j\rangle\not\equiv0\pmod m\) for all i ≠ j ∈ [t], we prove that t ≤ O(m n/2 + 8.47). This improves a recent bound of t ≤ m n/2 + O(log(m)) by [BDL13] and is the best possible up to the constant 8.47 when m is sufficiently larger than n.
An Endogenously Derived AK-model of Economic Growth

Assuming a production process with returns to scale that vary with the intensity it is operated at, an AK-model of endogenous growth with constant returns to scale in production is shown to arise due to replication driven by profit-maximization. If replication occurs at the efficiency-maximizing scale, the result applies also when the number of production processes must be discrete, thus overcoming the so-called integer problem. When competition is imperfect, there is only convergence toward the AK-model for large enough input use, so an economy is more prone to stalling in a steady-state without growth, the smaller and less competitive it is. Inefficient scaling also raises the risk of stalling.
Accretion Disks and Eruptive Phenomena

In the 1700’s, Immanuel Kant and the Marquis de Laplace proposed that the solar system collapsed from a gaseous medium of roughly uniform density ([79], [105]). A flattened gaseous disk — the protosolar nebula — formed out of this cloud. The Sun contracted out of material at the center of the disk, while the planets condensed in the outer portions. Despite its simplicity, this model suffered from the angular momentum problem inherent to star formation: a cloud of gas and dust with the diameter of the solar system and the mass of the Sun has too much angular momentum to collapse to the Sun’s present size. It took 150 years to solve this problem. C. von Weiszacker worked out the basic physics of a viscous accretion disk, building on previous realizations that a turbulent viscosity could move material inwards and angular momentum outwards through the protosolar nebula ([178], [179]). With Lust’s steady-state solution ([119]), Kant’s nebular hypothesis no longer suffered from the angular momentum problem and became the leading model for solar system formation.
Node splitting: a scheme for generating upper bounds in Bayesian networks

We formulate in this paper the mini-bucket algorithm for approximate inference in terms of exact inference on an approximate model produced by splitting nodes in a Bayesian network. The new formulation leads to a number of theoretical and practical implications. First, we show that branch-and-bound search algorithms that use mini-bucket bounds may operate in a drastically reduced search space. Second, we show that the proposed formulation inspires new mini-bucket heuristics and allows us to analyze existing heuristics from a new perspective. Finally, we show that this new formulation allows mini-bucket approximations to benefit from recent advances in exact inference, allowing one to significantly increase the reach of these approximations.
Cell list algorithms for nonequilibrium molecular dynamics

We present two modifications of the standard cell list algorithm that handle molecular dynamics simulations with deforming periodic geometry. Such geometry naturally arises in the simulation of homogeneous, linear nonequilibrium flow modeled with periodic boundary conditions, and recent progress has been made developing boundary conditions suitable for general 3D flows of this type. Previous works focused on the planar flows handled by Lees-Edwards or Kraynik-Reinelt boundary conditions, while the new versions of the cell list algorithm presented here are formulated to handle the general 3D deforming simulation geometry. As in the case of equilibrium, for short-ranged pairwise interactions, the cell list algorithm reduces the computational complexity of the force computation from O( N 2 ) to O(N), where N is the total number of particles in the simulation box. We include a comparison of the complexity and efficiency of the two proposed modifications of the standard algorithm.
Which Measures Count for the Public Interest

Abstract: The “measure” of this article is a bit different from most—there are almost as many words in the notes as in the body of the text. Notes are a significant part of my writing, both in terms of recognizing the connections and complexities among issues, trying to capture the richness of interdisciplinary teaching, and in terms of strengthening our struggles by (when relevant) referring to each other's work so that our individual work becomes understood as part of collective work to move mathematics education in the direction of the public interest. A quote I love that I often start my talks with, after saying how I talk in parentheses, although eventually closing most of them, is from a Hmong saying that translates “to speak of all kinds of things.” It is often used at the beginning of an oral narrative as a way of reminding listeners that the world is full of things that may not seem to be connected but actually are; that no event occurs in isolation; that you can miss a lot by sticking to the poi...
The Galactic center.

Over the last two decades, the refinement of radio and infrared techniques, as well as work in space, have provided a remarkable amount of information about the center of our galaxy. Much of it fits into a more or less understandable and increasingly well-defined pattern. However, some of this information seems to represent phenomena we do not yet understand, and still other measurements appear to challenge us with inconsistencies. Much of the material to be presented at this conference represents new results which will add both to our information and our understanding. It is hoped this first discussion will properly introduce the overall subject, paying particular attention to those areas which are still puzzling or under debate. Because of the wealth of material, the complexity of the subject, and my own limitations, not all of the many important points and questions will be treated, nor treated equally. Fortunately, the many gaps which I must leave will be filled by others, since there are review talks on most of the various, more specific aspects of the field.
Magnetic field-decay accelerator driven by a relativistic electron beam in a ferromagnetic waveguide

A novel high-gradient magnetic field-decay accelerator is presented in which the drive-beam leaves behind a high-gradient accelerating field produced by the magnetic field decay. The electromagnetic fields indicate a decaying function of the time. As an example, we obtain the acceleration field for the case of a short and intense drive bunch, which is represented by a parabolic function of time. With appropriate physical parameters, the acceleration gradient of the magnetic field-decay accelerator can be easily more than 150 megavolt/meter. >
Control of free head-neck movements in cats analyzed using a three-dimensional musculoskeletal model

A computer graphics model was used to analyze electromyographic (EMG) and kinematic data from the head and neck of two freely moving cats. The model was used to study two cats performing /spl plusmn/15/spl deg/ sinusoidal (0.25 Hz) head tracking movements in the sagittal plane. Cinefluoroscopic images revealed that vertebral motion described a nearly circular arc in a cat that was standing compared to a diagonal line in a cat that was lying prone. The prone lying animal had more acute angles between the vertebrae. The selection of muscles that were most strongly activated and the aiming of muscle activation differed between the two cats. EMG lead vertebral motion in the standing cat, but EMG was in phase with the peak up position of the head in the prone cat. Analysis of the model indicated that there was very little difference in the moment-generating capacity of each muscle between the two postures. Thus, we expect that the differences in the kinematics resulted from altered muscle activation patterns rather than differences in the musculoskeletal system in the two postures. >
Verification, Testing and Statistics

Formal verification is the holy grail of software validation. Practical applications of verification run into two major challenges. The first challenge is in writing detailed specifications, and the second challenge is in scaling verification algorithms to large software. In this talk, we present possible approaches to address these problems: We propose using statistical techniques to raise the level of abstraction, and automate the tedium in writing detailed specifications. We present our experience with the Merlin project [4], where we have used probabilistic inference to infer specifications for secure information flow, and discovered several vulnerabilities in web applications. We propose combining testing with verification to help scalability, an reducing false errors. We present our experience with the Yogi project [1,2,3,5], where we have built a verifier that combines static analysis with testing to find bugs and verify properties of low-level systems code.
The WTO Doha Round, Cotton Sector Dynamics and Poverty Trends in Zambia

The Zambian cotton sector went through significant reforms during the 1990s. After a long period of parastatal control, a process of liberalization in cotton production and marketing began in 1994. These reforms were expected to benefit agricultural farmers. In Zambia, these are rural, often vulnerable, smallholders. The authors investigate the connection between the dynamics of the cotton sector and the dynamics of poverty and evaluate to what extent cotton can work as a vehicle for poverty alleviation. They find that cotton can indeed act as an effective mechanism for increased household welfare. They also find income gains associated with cotton production, as well as positive impacts on the long-run nutritional status of Zambian children. The impacts, however, are relatively small.
Evacuation planning: a capacity constrained routing approach

Evacuation planning is critical for applications such as disaster management and homeland defense preparation. Efficient tools are needed to produce evacuation plans to evacuate populations to safety in the event of catastrophes, natural disasters, and terrorist attacks. Current optimal methods suffer from computational complexity and may not scale up to large transportation networks. Current naive heuristic methods do not consider the capacity constraints of the evacuation network and may not produce feasible evacuation plans. In this paper, we model capacity as a time series and use a capacity constrained heuristic routing approach to solve the evacuation planning problem. We propose two heuristic algorithms, namely Single-Route Capacity Constrained Planner and Multiple-Route Capacity Constrained Planner to incorporate capacity constraints of the routes. Experiments on a real building dataset show that our proposed algorithms can produce close-to-optimal solution, which has total evacuation time within 10 percent longer than optimal solution, and also reduce the computational cost to only half of the optimal algorithm. The experiments also show that our algorithms are scalable with respect to the number of evacuees.
Earthquake source parameters for the 2010 western Gulf of Aden rifting episode

SUMMARY On 2010 November 14, an intense swarm of earthquakes began in the western Gulf of Aden. Within a 48-hr period, 82 earthquakes with magnitudes between 4.5 and 5.5 were reported along an ∼80-km-long segment of the east–west trending Aden Ridge, making this swarm one of the largest ever observed in an extensional oceanic setting. In this study, we calculate centroid-moment-tensor solutions for 110 earthquakes that occurred between 2010 November and 2011 April. Over 80 per cent of the cumulative seismic moment results from earthquakes that occurred within 1 week of the onset of the swarm. We find that this sequence has a b-value of ∼1.6 and is dominated by normal-faulting earthquakes that, early in the swarm, migrate westwards with time. These earthquakes are located in rhombic basins along a section of the ridge that was previously characterized by low levels of seismicity and a lack of recent volcanism on the seafloor. Body-wave modelling demonstrates that the events occur in the top 2–3 km of the crust. Nodal planes of the normal-faulting earthquakes are consistent with previously mapped faults in the axial valley. A small number of strike-slip earthquakes observed between two basins near 44°E, where the axial valley changes orientation, depth and width, likely indicate the presence of an incipient transform fault and the early stages of ridge-transform segmentation. The direction of extension accommodated by the earthquakes is intermediate between the rift orthogonal and the direction of relative motion between the Arabian and Somalian plates, consistent with the oblique style of rifting occurring along the slow-spreading Aden Ridge. The 2010 swarm shares many characteristics with dyke-induced rifting episodes from both oceanic and continental settings. We conclude that the 2010 swarm represents the seismic component of an undersea magmatic rifting episode along the nascent Aden Ridge, and attribute the large size of the earthquakes to the combined effects of the slow spreading rate, relatively thick crust and recent quiescence. We estimate that the rifting episode was caused by dyke intrusions that propagated laterally for 12–18 hr, accommodating ∼1–14 m of opening or ∼85–800 yr of spreading along this section of the ridge. Our findings demonstrate the westward propagation of active seafloor spreading into this section of the western Gulf of Aden and illustrate that deformation at the onset of seafloor spreading may be accommodated by discrete episodes of faulting and magmatism. A comparison with similar sequences on land suggests that the 2010 episode may be only the first of several dyke-induced rifting episodes to occur in the western Gulf of Aden.
Quasi‐Optical Circuits

Quasioptical circuits use components typically associated with optics, such as lenses, mirrors, and polarizers, but are targeted toward the millimeter- and sub-millimeter-wave regimes of the electromagnetic spectrum between 30GHz and a few terahertz. This article focuses on active quasioptical circuits used for generating, amplifying, and processing millimeter-wave beams. Keywords: quaisoptical power combining; millimeter-wave systems; quasioptical circuit; oscillator; amplifier; frequency conversion; beam control array
How will China's saving-investment balance evolve?

This paper investigates how China's saving, investment, and saving-investment balance will evolve in the decades ahead. Household saving in China is relatively high compared with OECD countries. However, much of China's high economywide saving, and the difference between China and other countries, are due to unusually high enterprise and government saving. Moreover, cross-country empirical analysis shows that economywide saving and investment in China are higher than what would be expected, even adjusting for differences in economic structure. Combined, these findings suggest that much of China's high saving is the result of policies particular to China. Looking ahead, the econometric results suggest that purely on the basis of projected structural developments-including development, changes in economic structure, urbanization, and demographics-saving and investment would both decline only mildly in the coming two decades, with ambiguous impact on the current account surplus. However, the potential effect on saving, investment, and the saving-investment balance of several policy adjustments could be large. Several of these policies are identified and their likely impact assessed and quantified. This exercise suggests that rebalancing along these lines should reduce both saving and the current account surplus over time, although the surplus is unlikely to turn into a deficit soon.
A statistical mechanics model for the collective epigenetic histone modification dynamics

Epigenetic histone modifications play an important role in the maintenance of different cell phenotypes. The exact molecular mechanism for inheritance of the modification patterns over cell generations remains elusive. We construct a Potts-type model based on experimentally observed nearest-neighbor enzyme lateral interactions and nucleosome covalent modification state biased enzyme recruitment. The model can lead to effective nonlocal interactions among nucleosomes suggested in previous theoretical studies, and epigenetic memory is robustly inheritable against stochastic cellular processes.
Flag f-vectors of three-colored complexes

The flag $f$-vectors of three-colored complexes are characterized. This also characterizes the flag $h$-vectors of balanced Cohen-Macaulay complexes of dimension two, as well as the flag $h$-vectors of balanced shellable complexes of dimension two.
Effect of High helium Content on Stainless-Steel Swelling

Type 316 stainless-steel specimens have been irradiated in the High Flux Isotope Reactor at temperatures between 380 and 680°C to displacement damage levels up to 120 displacements per atom and tra...
Symplectic Parshin-Arakelov Inequality

Lefschetz fibration is the symplectic analogue of stable holomorphic fibration in complex geometry. A 4-dimensional stable holomorphic fibration satisfies the famous Parshin-Arakelov inequality. In this note we present an analogous inequality for a 4-dimensional Lefschetz fibration.
Light charged Higgs bosons to AW/HW via top decay

While current ATLAS and CMS measurements exclude a light charged Higgs (m H ± < 160 GeV) for most of the parameter region in the context of the MSSM scenarios, these bounds are significantly weakened in the Type II 2HDM once the exotic decay channel into a lighter neutral Higgs, H ± → AW/HW, is open. In this study, we examine the possibility of a light charged Higgs produced in top decay via single top or top pair production, which is the most prominent production channel for a light charged Higgs at the LHC. We consider the subsequent decay H ± → AW/HW, which can reach a sizable branching fraction at low tan β once it is kinematically permitted. With a detailed collider analysis, we obtain exclusion and discovery bounds for the 14 TeV LHC assuming the existence of a 70 GeV neutral scalar. Assuming BR(H ± → AW/HW) = 100% and BR(A/H → ττ) = 8.6%, the 95% exclusion limits on BR(t → H + b) are about 0.2% and 0.03% for single top and top pair production respectively, with an integrated luminosity of 300 fb−1. The discovery reaches are about 3 times higher. In the context of the Type II 2HDM, discovery is possible at both large tan β > 17 for 155 GeV < m H ± < 165 GeV, and small tan β < 6 over the entire mass range. Exclusion is possible in the entire tan β versus $$ {m}_{H^{\pm }} $$ plane except for charged Higgs masses close to the top threshold. The exotic decay channel H ± → AW/HW is therefore complementary to the conventional H ± → τν channel.
The first calculation of fractional jets

In collider physics, jet algorithms are a ubiquitous tool for clustering particles into discrete jet objects. Event shapes offer an alternative way to characterize jets, and one can define a jet multiplicity event shape, which can take on fractional values, using the framework of “jets without jets”. In this paper, we perform the first analytic studies of fractional jet multiplicity N jet in the context of e + e − collisions. We use fixed-order QCD to understand the N jet cross section at order α 2 , and we introduce a candidate factorization theorem to capture certain higher-order effects. The resulting distributions have a hybrid jet algorithm/event shape behavior which agrees with parton shower Monte Carlo generators. The N jet observable does not satisfy ordinary soft-collinear factorization, and the N jet cross section exhibits a number of unique features, including the absence of collinear logarithms and the presence of soft logarithms that are purely non-global. Additionally, we find novel divergences connected to the energy sharing between emissions, which are reminiscent of rapidity divergences encountered in other applications. Given these interesting properties of fractional jet multiplicity, we advocate for future measurements and calculations of N jet at hadron colliders like the LHC.
Review of logistics service regulations for freight forwarding businesses: what should be addressed for a better logistics regulatory framework ?

Regulatory frameworks on logistics regulations are often opaque, especially in developing countries, because of the complex nature of logistics services. World Bank client countries have faced difficulty finding the issues that hinder them from improving logistics competence. Therefore, it is beneficial to understand how the logistics service industry is regulated and what should be addressed in building the regulatory framework to improve logistics competence. This note proposes questions to be addressed for beneficial regulations by reviewing existing logistics service regulations in 14 countries, particularly regulations for the freight forwarding industry. These questions will help in assessing a regulatory framework and identifying regulatory weaknesses. This note suggests that the regulatory framework should take into consideration national recognition of freight forwarding business, an institutional arrangement with clear division of responsibility among stakeholders, and streamlined but flexible regulations adapted to the country context.
Macronutrient Deprivation Modulates Antigen Trafficking and Immune Recognition through HSC70 Accessibility

B lymphocytes exploit macroautophagy to capture cytoplasmic and nuclear proteins within autophagosomes. Fusion of autophagosomes with lysosomes and endosomes facilitates content proteolysis, with the resulting peptides selectively binding MHC class II (MHC II) molecules, which are displayed for recognition by T lymphocytes. Nutrient deprivation or stress amplified this pathway, favoring increased MHC II presentation of cytoplasmic Ags targeted to autophagosomes. By contrast, this stress diminished MHC II presentation of membrane Ags including the BCR and cytoplasmic proteins that use the chaperone-mediated autophagy pathway. Whereas intracellular protease activity increased with nutrient stress, endocytic trafficking and proteolytic turnover of the BCR was impaired. Addition of macronutrients such as high molecular mass proteins restored endocytosis and Ag presentation, evidence of tightly regulated membrane trafficking dependent on macronutrient status. Altering cellular levels of the cytosolic chaperone HSC70 was sufficient to overcome the inhibitory effects of nutritional stress on BCR trafficking and Ag presentation. Together, these results reveal a key role for macronutrient sensing in regulating immune recognition and the importance of HSC70 in modulating membrane trafficking pathways during cellular stress.
A Comparison of Enameled and Stainless Steel Surfaces

Several properties important to appliance finishes of porcelain enamel are compared to stainless steel. These include cleanability, scratch resistance, abrasion resistance, heat resistance, and stain resistance. Also, a new stainless-style enamel cover coat is introduced.
High-velocity clouds as streams of ionized and neutral gas in the halo of the Milky Way

High-velocity clouds (HVCs), fast-moving ionized and neutral gas clouds found at high galactic latitudes, may play an important role in the evolution of the Milky Way. The extent of this role depends sensitively on their distances and total sky covering factor. We search for HVC absorption in Hubble Space Telescope high-resolution ultraviolet (UV) spectra of a carefully selected sample of 133 active galactic nuclei (AGN) using a range of atomic species in different ionization stages (e.g. O i, C ii, C iv, Si ii, Si iii, Si iv). This allows us to identify neutral, weakly ionized or highly ionized HVCs over several decades in H i column densities. The sky covering factor of UV-selected HVCs with |vLSR| ≥ 90 km s−1 is about 68 per cent for the Galactic sky at . About 74 per cent of the HVC directions have cm−2 and 46 per cent have cm−2. We show that our survey is essentially complete, i.e. an undetected population of HVCs with extremely low H (H i + H ii) column density is unlikely to be important for the HVC mass budget. We confirm that the predominantly ionized HVCs contain at least as much mass as the traditional H i HVCs and show that large H i HVC complexes have generally ionized envelopes extending far from the H i contours. There are also large regions of the Galactic sky that are covered with ionized high-velocity gas with little H i emission nearby. We show that the covering factors of HVCs with km s−1 drawn from the AGN and stellar (with stars at d > 3 kpc) samples are similar. This confirms that most of the HVCs are within 5–15 kpc of the sun. The HVCs with |vLSR |≳170 km s−1 are largely associated with the Magellanic Stream at b 20° as well as other large known H i complexes. We conclude that there is no evidence in the Local Group that any galaxy shows a population of HVCs extending much farther away than 50 kpc from its host, except possibly for those tracing remnants of galaxy interaction.
Learning Bayesian nets that perform well

A Bayesian net (BN) is more than a succinct way to encode a probabilistic distribution; it also corresponds to a function used to answer queries. A BN can therefore be evaluated by the accuracy of the answers it returns. Many algorithms for learning BNs, however, attempt to optimize another criterion (usually likelihood, possibly augmented with a regularizing term), which is independent of the distribution of queries that are posed. This paper takes the "performance criteria" seriously, and considers the challenge of computing the BN whose performance -- read "accuracy over the distribution of queries" -- is optimal. We show that many aspects of this learning task are more difficult than the corresponding subtasks in the standard model.
Hidden Mobile Guards in Simple Polygons

We consider guarding classes of simple polygons using mobile guards (polygon edges and diagonals) under the constraint that no two guards may see each other. In contrast to most other art gallery problems, existence is the primary question: does a specic type of polygon admit some guard set? Types include simple polygons and the subclasses of orthogonal, monotone, and starshaped polygons. Additionally, guards may either exclude or include the endpoints (so-called open and closed guards). We provide a nearly complete set of answers to existence questions of open and closed edge, diagonal, and mobile guards in simple, orthogonal, monotone, and starshaped polygons, with some surprising results. For instance, every monotone or starshaped polygon can be guarded using hidden open mobile (edge or diagonal) guards, but not necessarily with hidden open edge or hidden open diagonal guards.
Earth‐inductor measurements aboard the Carnegie, Cruise VII

On the recently ended last cruise of the non-magnetic vessel Carnegie the earth inductor was used for the routine measurement of inclination and, experimentally, for the measurement of the horizontal intensity of the Earth's magnetic field.
Adaptive induced fluctuations for multiuser diversity

This paper investigates multiuser diversity in the context of cellular networks, with emphasis on the gains that can be achieved by adaptively inducing fluctuations in the environment. In a cellular system that at any time schedules for service the user with the best channel at that time, the expected service rate increases with the variability of the channel. Controlling the fluctuations using available feedback can further increase the expected service rate. This paper proposes a scheme for controlling fluctuations using only the feedback required to exploit multiuser diversity. Fluctuations are induced by introducing at the base station another transmit antenna that sends out the same signal but at a different phase from the first one, and then adaptively varying the phase difference. The performance of the scheme (for the same total transmitted power) is evaluated when the users are infinitely back-logged or have finite queues, and when the channels are Rayleigh or Ricean distributed. Fairness issues and performance of the scheme under an additional fairness mechanism are also investigated in the context of users with finite queues. In all scenarios the performance is better when fluctuations are adaptively induced than when the fluctuations are randomly induced or not induced at all
A short synthesis of antitumor ether thioglycolipids: Thioglycosidation of a glucose donor with a tributylstannyl sulfide acceptor

Abstract Efficient routes to α- and β-thioglucolipids 1a and 1b are described starting from 1- O -hexadecyl-3- O -( p -toluenesulfonyl)- sn -glycerol ( 2 ) in 72% and 68% overall yields, respectively. Deprotection of the S -benzyl group of the glyceride 4 with tri- n -butyltin hydride produced the tin derivative 5 , which was glycosidated with a glucose donor.
Trade Liberalization and New Imported Inputs

Understanding the role of international trade in explaining vast differences in productivity across countries remains a key question in inter national economics. Recent literature empha sizes the microfoundations underlying this relationship. One strand of literature highlights how new export opportunities and toughness of competition generate aggregate productiv ity gains by reallocating resources from less to more productive firms (Marc J. Melitz 2003; Melitz and Gianmarco Ottaviano 2008). Trade also increases aggregate productivity through improvements in firm productivity (Pavcnik 2002), which have recently been linked to the reallocation of resources across products within firms (Andrew B. Bernard, Stephan J. Redding, and Peter K. Schott 2006) and use of imported inputs (Mary Amiti and Jozef Konings 2007). The latter relate to the idea that trade provides domestic firms access to cheaper and previously unavailable inputs. The idea that international trade benefits
Computation of Hypersonic Turbulent Boundary Layers with Heat Transfer

Theme T concept of eddy viscosity has been applied to predict turbulent boundary layers in hypersonic flow regions.' Hopkins et al. found that the multilayer viscosity model underpredicts the skin-friction coefficient by around 10% for hypersonic flow conditions. The neglected density fluctuation terms in the Reynolds stress were identified as the cause of this deficiency. Recent experimental investigations on turbulent boundary layers revealed that the turbulent transport of energy decreases more rapidly toward the wall than the momentum transport. Their results seem to indicate that the heat transfer and temperature profile of turbulent flows cannot be ascertained by an oversimplified constant turbulent Prandtl number. At hypersonic Mach numbers, experimental data also recorded a distinct normal pressure gradient within the turbulent boundary layer. At the present time, no analytical method or systematic evaluation has been attempted to include these phenomena. The present analysis intends to determine the significance of the aforementioned phenomena and also to provide suitable means to improve the numerical prediction scheme for hypersonic turbulent boundary layers.
General Overview of Black Hole Accretion Theory

I provide a broad overview of the basic theoretical paradigms of black hole accretion flows. Models that make contact with observations continue to be mostly based on the four decade old alpha stress prescription of Shakura and Sunyaev (1973), and I discuss the properties of both radiatively efficient and inefficient models, including their local properties, their expected stability to secular perturbations, and how they might be tied together in global flow geometries. The alpha stress is a prescription for turbulence, for which the only existing plausible candidate is that which develops from the magnetorotational instability (MRI). I therefore also review what is currently known about the local properties of such turbulence, and the physical issues that have been elucidated and that remain uncertain that are relevant for the various alpha-based black hole accretion flow models.
A geometric interpretation of Milnor's triple linking numbers

Milnor's triple linking numbers of a link in the 3-sphere are interpreted geometrically in terms of the pattern of intersections of the Seifert surfaces of the components of the link. This generalizes the well known formula as an algebraic count of triple points when the pairwise linking numbers vanish.
Iodination of organic substrates with halide salts and H2O2 using an organotelluride catalyst.

Organotelluride 1 is a water-soluble catalyst for the oxidation of iodide with hydrogen peroxide in pH 6 phosphate buffer. In two-phase systems, organic substrates are efficiently iodinated using 0.8 mol % of catalyst. Water-soluble substrates are iodinated without an organic cosolvent.
Simulation and reversal of n-qubit Hamiltonians using Hadamard matrices

The ability to simulate one Hamiltonian with another is an important primitive in quantum information processing. In this paper, a simulation method for arbitrary σ z ⊗ σ z interaction based on Hadamard matrices is generalized for any pairwise interaction. We describe two applications of the generalized framework. First, we obtain a class of protocols for selecting an arbitrary interaction term in an n -qubit Hamiltonian. This class includes the scheme given by Dodd et al. Second, we obtain a class of protocols for inverting an arbitrary, possibly unknown n -qubit Hamiltonian, generalizing the result by Janzing et al.
THE ASSEMBLY OF GALAXY CLUSTERS

We study the formation of fifty-three galaxy cluster-size dark matter halos (M = 10{sup 14.0-14.76} M{sub {circle_dot}}) formed within a pair of cosmological {Lambda}CDM N-body simulations, and track the accretion histories of cluster subhalos with masses large enough to host {approx} 0.1L{sub *} galaxies. By associating subhalos with cluster galaxies, we find the majority of galaxies in clusters experience no 'pre-processing' in the group environment prior to their accretion into the cluster. On average, {approx} 70% of cluster galaxies fall into the cluster potential directly from the field, with no luminous companions in their host halos at the time of accretion; and less than {approx} 12% are accreted as members of groups with five or more galaxies. Moreover, we find that cluster galaxies are significantly less likely to have experienced a merger in the recent past ({approx}< 6 Gyr) than a field halo of the same mass. These results suggest that local, cluster processes like ram-pressure stripping, galaxy harassment, or strangulation play the dominant role in explaining the difference between cluster and field populations at a fixed stellar mass; and that pre-evolution or past merging in the group environment is of secondary importance for setting cluster galaxy properties for mostmore » clusters. The accretion times for z = 0 cluster members are quite extended, with {approx} 20% incorporated into the cluster halo more than 7 Gyr ago and {approx} 20% within the last 2 Gyr. By comparing the observed morphological fractions in cluster and field populations, we estimate an approximate time-scale for late-type to early-type transformation within the cluster environment to be {approx} 6 Gyr.« less
Matrix-isolation infrared and computer simulation spectra of M(CH3)nCl4−n (M = Si, Ge and Sn) type compounds in the M-C and M-Cl stretching regions

Abstract The IR spectra of the M(CH3)nCl4−n (M = Si, Ge and Sn; n = 4,3,2 and 1) type compounds have been measured in argon and nitrogen matrices at ~ 15 K. The isotope structures have been observed for most of the M-C and M-Cl stretching bands, and assigned by using the computer simulation technique. Relative displacements of individual atoms have been calculated from the observed isotope shifts.
Calorimetric measurements on electrochemical cells with Pd-D cathodes

Two series of experiments were performed to determine the conditions of cell operation that produce sufficient excess heat to be useful for the production of energy. In the first series, the results from a differential temperature analysis of identical light- and heavy-water electrochemical cells were too ambiguous and, thus, not suitable for evaluating excess heat effects. In the second series, two Pd-D/LiOD-saturated D2O/Pt cells were operated at current densities between 12.5–500 mA/cm2 in a constant-heatloss-rate twin calorimeter for 460 hours. Water loss measurements during the experiments indicated that the recombination reaction (2D2 + O2 → 2D2O) did not occur. The D/Pd ratio was determined gravimetrically during the experiments. No excess heat was found within the sensitivity (0.13 W, 0.082 W/cm3 of Pd, 0.013 W/cm2 of Pd) and precision (±0.3 W) of the calorimeter.
Growth and Integrability of Fourier Transforms on Euclidean Space

A fundamental theme in classical Fourier analysis relates smoothness properties of functions to the growth and/or integrability of their Fourier transform. By using a suitable class of $$L^{p}$$ -multipliers, a rather general inequality controlling the size of Fourier transforms for large and small argument is obtained. As consequences, quantitative Riemann–Lebesgue estimates are obtained and an integrability result for the Fourier transform is developed extending ideas used by Titchmarsh in the one dimensional setting.
Do Distinct Cosmological Models Predict Degenerate Halo Populations

Using cosmological N-body simulations, we investigate the influence of the matter density parameter Ωm and the linear theory power spectrum P(k) on statistical properties of the dark matter halo population—the mass function n(M), two-point correlation function ξ(r), and pairwise velocity statistics v12(r) and σ12(r). For fixed linear theory P(k), the effect of changing Ωm is simple: the halo mass scale M* shifts in proportion to Ωm, pairwise velocities (at fixed M/M*) are proportional to Ω, and halo clustering at fixed M/M* is unchanged. If one simultaneously changes the power spectrum amplitude σ8 to maintain the "cluster normalization" condition σ8Ω = const, then n(M) stays approximately constant near M ~ 5 × 1014 h-1 M☉, and halo clustering and pairwise velocities are similar at fixed M. However, the shape of n(M) changes, with a decrease of Ωm from 0.3 to 0.2, producing a ~30% drop in the number of low-mass halos. One can preserve the shape of n(M) over a large dynamic range by changing the spectral tilt ns or shape parameter Γ, but the required changes are substantial—e.g., masking a decrease of Ωm from 0.3 to 0.2 requires Δns ≈ 0.3 or ΔΓ ≈ 0.15. These changes to P(k) significantly alter the halo clustering and halo velocities. The sensitivity of the dark halo population to cosmological model parameters has encouraging implications for efforts to constrain cosmology and galaxy bias with observed galaxy clustering, since the predicted changes in the halo population cannot easily be masked by altering the way that galaxies occupy halos. A shift in Ωm alone would be detected by any dynamically sensitive clustering statistic; a cluster normalized change to σ8 and Ωm would require a change in galaxy occupation as a function of M/M*, which would alter galaxy clustering; and a simultaneous change to P(k) that preserves the halo mass function would change the clustering of the halos themselves.
Fast implementation of matched-filter-based automatic alignment image processing

Video images of laser beams imprinted with distinguishable features are used for alignment of 192 laser beams at the National Ignition Facility (NIF). Algorithms for determining the position of these beams enable control systems to perform the task of alignment. Real world beam images suffer from intensity fluctuation or other distortions, making algorithms susceptible to higher position measurement variability. Using matched filtering to identify beam positions results in greater stability of position measurement compared to centroiding techniques. However, this gain is achieved at the expense of extra processing time. This work explores the use of FPGAs to accelerate these computations. Results indicate a performance improvement of 20 times for an FPGA over a 3 GHz Pentium 4 processor.