cssi/SciSciGPT-SciSciNet huggingface dataset:
Hydrogen collisions in planetary atmospheres, ionospheres, and magnetospheres

Hydrogen is the most abundant element in the universe. Molecular hydrogen is the dominant chemical species in the atmospheres of the giant planets. Because of their low masses, neutral and ionized hydrogen atoms are the dominant species in the high atmospheres of many planets. Finally, protons are the principal heavy component of the solar wind. Here we present a critical evaluation of the current state of understanding of the chemical reaction rates and collision cross sections for several important hydrogen collision processes in planetary atmospheres, ionospheres, and magnetospheres. Accurate ab initio quantum theory will play an important role. The collision processes are grouped as follows: (a) H++H charge transfer, (b) H++H2(v) charge transfer and vibrational relaxation, and (c) H2(v,J)+H2 vibrational, rotational, and ortho–para relaxation. In each case we provide explicit representations as tabulations or compact formulas. Particularly important conclusions are that H++H2(v) collisions are more likely to result in vibrational relaxation than charge transfer and H2 ortho–para conversion is at least an order-of-magnitude faster than previously assumed.
Lower Bounds on Information Transfer in Distributed Computations

Lower bounds on the interprocessor communication required for computing a differentiable real-valued function in a distributed network are derived. These bounds are independent of the network interconnection configuration, and they impose no assumptions other than differentiability constraints on the computations performed by individual processors. As a sample application, lower bounds on information transfer in the distributed computation of some-typical matrix operations are exhibited.
Turbulent Heat Transfer Studies in Annulus With Inner Cylinder Rotation

Experimental investigations of turbulent heat transfer are made in a large-gap annulus with both rotating and nonrotating inner cylinder. The vertical annular channel has an electrically heated outer wall; the inner wall i thermally and electrically insulated. The axial air flow is allowed to develop before rotation and heating are imparted. The resulting temperature fields are investigated using thermocouple probes located near the channel exit. The wall heat flux, wall axial temperature development, and radial temperature profiles are measured. For each axial Reynolds number, three heat flux rates are used. Excellent correlation is established between rotational and nonrotational Nusselt number. The proper correlation parameter is a physical quantity characterizing the flow helix. This parameter is the inverse of the ratio of axial travel of the flow helix in terms of hydraulic diameter, per half revolution of the spinning wall.
Interplay of charge and orbital ordering in manganese perovskites

A model of localized classical electrons coupled to lattice degrees of freedom and, via the Coulomb interaction, to each other has been studied to gain insight into the charge and orbital ordering observed in lightly doped manganese perovskites. Expressions are obtained for the minimum energy and ionic displacements caused by given hole and electron orbital configurations. The expressions are analyzed for several hole configurations, including that experimentally observed by Yamada et al. [Phys. Rev. Lett. 77, 904 (1996)] in ${\mathrm{La}}_{7/8}{\mathrm{Sr}}_{1/8}{\mathrm{MnO}}_{3}.$ We find that, although the preferred charge and orbital ordering depend sensitively on parameters, there are ranges of the parameters in which the experimentally observed hole configuration has the lowest energy. For these parameter values we also find that the energy differences between different hole configurations are on the order of the observed charge ordering transition temperature. The effects of additional strains are also studied. Some results for ${\mathrm{La}}_{1/2}{\mathrm{Ca}}_{1/2}{\mathrm{MnO}}_{3}$ are presented, although our model may not adequately describe this material because the high-temperature phase is metallic.
Lattice-Matched Transition Metal Disulfide Intergrowths: The Metallic Conductors Ag2Te(MS2)3 (M = V, Nb)

We present new chalcogenide compounds, Ag2Te(MS2)3 (M = V, Nb), built up of alternating planes of [MS2] and [Ag2Te]. The Ag and Te atoms are linearly coordinated by S atoms in the [MS2] layers and held in place by covalent interactions. Structural polymorphism was found by single crystal X-ray diffraction studies, where long-range ordering or disorder of the Ag and Te atoms within the hexagonal planar [Ag2Te] layer yielded two distinct crystal forms. When the Ag and Te atoms are ordered, the two isostructural compounds crystallize in the non-centrosymmetric P62m space group, with a = 5.5347(8) A, c = 8.0248(16) A, and V = 212.89(6) A3 for α-Ag2Te(VS2)3 and a = 5.7195(8) A, c = 8.2230(16) A, and V = 232.96(6) A3 for α-Ag2Te(NbS2)3. For the occupationally disordered Ag/Te arrangement, a subcell of the ordered phase that crystallizes in the non-centrosymmetric P6m2 space group, with a = 3.2956(6) A (=aa/(3)1/2), c = 8.220(2) A, and V = 77.31(3) A3 for β-Ag2Te(VS2)3, was identified. Furthermore, pair distri...
A tight upper bound on the benefits of replication and consistency control protocols

We present an upper bound on the performance provided by a protocol guaranteeing mutually exclusive access to a replicated resource in a network subject to component failure and subsequent partitioning. The bound is presented in terms of the performance of a single resource in the same network. The bound is tight and is the first such bound known to us. Since mutual exclusion is one of the requirements for maintaining the consistency of a database object, this bound provides an upper limit on the availability provided by any database consistency control protocol, including those employing dynamic data relocation and replication. We show that if a single copy provides availability A for 0 ? A ? 1, then no scheme can achieve availability greater than ?A in the same network. We show this bound to be the best possible for any network with availability greater than .25. Although, as we proved, the problem of calculating A is #P-complete, we describe a method for approximating the optimal location for a single copy which adjusts dynamically to current network characteristcs. This bound is most useful for high availabilities, which tend to be obtainable with modern networks and their constituent components.
Can a Circulating Light Beam Produce a Time Machine

In a recent paper, Mallett found a solution of the Einstein equations in which closed timelike curves (CTC’s) are present in the empty space outside an infinitely long cylinder of light moving in circular paths around an axis. Here we show that, for physically realistic energy densities, the CTC’s occur at distances from the axis greater than the radius of the visible universe by an immense factor. We then show that Mallett’s solution has a curvature singularity on the axis, even in the case where the intensity of the light vanishes. Thus it is not the solution one would get by starting with Minkowski space and establishing a cylinder of light.
Does Compensating the Losers Increase Support for Trade? An Experimental Test of the Embedded Liberalism Thesis

The political economy of trade literature argues that compensating those who lose from trade is an important component of maintaining public support for free trade, a linkage known as the compensation hypothesis or embedded liberalism thesis. Previous research has found support for many elements of the causal chain underlying embedded liberalism; however, there has been little research on the most crucial element of the causal chain, namely that compensation policies lead to increased support for trade. This article provides a direct test of the compensation hypothesis using a survey-based experiment conducted in the United States that exposes half of the respondents to knowledge of compensation programs and then asks for their opinion on trade policy. The article explores whether knowledge of compensation increases support for trade as well as who is influenced by this knowledge and, thus, provides a crucial test of the embedded liberalism thesis.
Business Analysis: A Hotbed for Strategy Ideas

The rapidly changing business environment of the 1990's forced the oil and gas industry to develop new corporate and regional strategies to remain competitive. To support strategy development, much attention has been given to such analytical tools as decision and risk analysis and probabilistic modeling. Often overlooked, however, is that a solid foundation of information and a thorough understanding of the underlying business environment are required for these tools to be effective. The business-analysis process provides this understanding and serves as a hotbed for new strategic ideas. This paper presents several business-analysis tools that enhance awareness of the business environment and provide the foundation of information necessary for sound strategic modeling. Examples from a recent study show how tools, such as influence diagrams, value-chain analysis, benchmarking, competitor analysis, scenario development, and strength and weakness analysis, are used.
Distribution of gamma-ray burst ejecta energy with Lorentz factor

The early X-ray afterglow for a significant number of gamma-ray bursts detected by the Swift satellite is observed to have a phase of very slow flux decline with time (F{sub {nu}} {proportional_to} t{sup -{alpha}} with 0.2 {approx}< {alpha} {approx}< 0.8) for 10{sup 2.5} s{approx}< t {approx}< 10{sup 4} s, while the subsequent decline is the usual 1 {approx}< {alpha}{sub 3} {approx}< 1.5 behavior, that was seen in the pre-Swift era. We show that this behavior is a natural consequence of a small spread in the Lorentz factor of the ejecta, by a factor of {approx} 2-4, where the slower ejecta gradually catch-up with the shocked external medium, thus increasing the energy of forward shock and delaying its deceleration. The end of the ''shallow'' flux decay stage marks the beginning of the Blandford-McKee self similar external shock evolution. This suggests that most of the energy in the relativistic outflow is in material with a Lorentz factor of {approx} 30-50.
Diastereoselectivity control in the zirconocene-mediated ring contraction of 4-vinylfuranosides to enantiopure multiply functionalized cyclobutanes.

The ring contraction induced by treatment of 4-vinylfuranosides with zirconocene in the presence of boron trifluoride etherate can be rendered highly diastereoselective by proper adjustment of substituent stereochemistry. The two competing transition states that are seemingly involved appear to be usefully sensitive to nonbonded steric interactions.
Performance evaluation of high-speed interconnects using dense communication patterns

We study the performance of high-speed interconnects using a set of communication micro-benchmarks. The goal is to identify certain limiting factors and bottlenecks with these interconnects. Our micro-benchmarks are based on dense communication patterns with different communicating partners and varying degrees of these partners. We tested our micro-benchmarks on five platforms: an IBM system of 68-node 16-way Power3, interconnected by a SP switch2; another IBM system of 264-node 4-way Power PC 604e, interconnected by an SP switch; a Compaq cluster of 128-node 4-way ES40/EV67 processor, interconnected by an Quadrics interconnect; an Intel cluster of 16-node dual-CPU Xeon, interconnected by an Quadrics interconnect; and a cluster of 22-node Sun Ultra Sparc, interconnected by an Ethernet network. Our results show many limitations of these networks including the memory contention within a node as the number of communicating processors increased and the limitations of the network interface for communication between multiple processors of different nodes.
Costs of Inaction on Maternal Mortality: Qualitative Evidence of the Impacts of Maternal Deaths on Living Children in Tanzania

Little is known about the interconnectedness of maternal deaths and impacts on children, beyond infants, or the mechanisms through which this interconnectedness is established. A study was conducted in rural Tanzania to provide qualitative insight regarding how maternal mortality affects index as well as other living children and to identify shared structural and social factors that foster high levels of maternal mortality and child vulnerabilities. Adult family members of women who died due to maternal causes (N = 45) and key stakeholders (N = 35) participated in in-depth interviews. Twelve focus group discussions were also conducted (N = 83) among community leaders in three rural regions of Tanzania. Findings highlight the widespread impact of a woman's death on her children's health, education, and economic status, and, by inference, the roles that women play within their families in rural Tanzanian communities. The full costs of failing to address preventable maternal mortality include intergenerational impacts on the nutritional status, health, and education of children, as well as the economic capacity of families. When setting priorities in a resource-poor, high maternal mortality country, such as Tanzania, the far-reaching effects that reducing maternal deaths can have on families and communities, as well as women's own lives, should be considered.
Managing the Public to Manage Data: Citizen Science and Astronomy

Citizen Cyberscience Projects (CCPs) that recruit members of the public as volunteers to process and produce large datasets promise a great deal of benefits to scientists and science. However, if this promise is to be realised, and citizen science-produced datasets are to be widely used by scientists, it is essential that these datasets win the trust of the scientific community. This task of securing credibility involves, in part, applying standard scientific procedures to clean up datasets formed by volunteer contributions. However, the management of volunteers’ behaviour in terms of how they contribute also plays a significant role in improving both the quality of individual contributions and the overall robustness of the resultant datasets. This can assist CCPs in securing a reputation for producing trustworthy datasets. Through a case study of Galaxy Zoo, a CCP set up to generate datasets based on volunteer classifications of galaxy morphologies, this paper explores how those involved in running the project manage volunteers. In particular, it focuses on how methods for crediting volunteer contributions motivate volunteers to provide higher quality contributions and to behave in a way that better corresponds to statistical assumptions made when combining volunteer contributions into datasets. These methods have made a significant contribution to the success of the project in securing trust in these datasets, which have been well used by other scientists. Implications for practice are then presented for CCPs, providing a list of considerations to guide choices regarding how to credit volunteer contributions to improve the quality and trustworthiness of citizen science-produced datasets.
Hydrodynamic Problems in Oil-Spill Control And Removal

The author analyzes the fluid mechanics involved in dispersion of oil spills and in various devices for cleaning up spills. Mathematical models are developed for three types of oil skimmers: weir, rotating-disk, and endless oleophilic-belt skimmers. Analysis of the model equations should aid in optimizing performance of each type of skimmer.
Increasing the Resilience of Financial Intermediaries through Portfolio-Level Insurance against Natural Disasters

Financial intermediaries [FIs] in developing and emerging economies are poorly equipped to manage natural disasters. These events create losses for FIs, eroding capital reserves and compromising their ability to lend. Portfolio-level insurance against disasters can improve FI management of these events. We model microfinance intermediaries [MFIs] exposed to severe El Nino in Peru that can now insure against this disaster risk. Our analyses suggest that insurance allows these lenders to manage this risk more efficiently and effectively. These risk management improvements can translate into better financial performance, expansion of banking service outreach, lower interest rates, and reduced volatility in access to credit. Based on these analyses, a large MFI in Peru with which we collaborated is now managing its disaster risk using El Nino insurance.
Target Association Using Detection Methods

A residual-based scheme is presented for solving the radar track-to-track association problem using bearings-only measurements. To accomplish track association between two stations, the residuals of a bank of nonlinear filters called modified gain extended Kalman filters are analyzed. Once tracks have been associated between two stations, tracks from additional stations may be associated with tracks from the first two stations by checking algebraic parity equations. Traditional track association methods rely on the local stations' estimated target positions and error variances. These local estimates may be quite inaccurate or even divergent when using bearings-only measurements. Our method bypasses this difficulty because our filters use raw data from multiple stations. An example demonstrates that our methods yield results superior to those of standard methods.
Real GPA and Real SET: two antidotes to greed, sloth and cowardice in the college classroom

Recently published evidence of limited learning among American college students confirms the damage done when students, faculty and institutions pursue interests that conflict with the educational process. The ‘disengagement compact’ in which faculty tacitly trade lenient workloads and grading for higher student evaluation of teaching (SET) scores and fewer complaints from students does damage wherever it operates. The work of Johnson confirms the link between SET and grade inflation. We propose a modification of an earlier grade index, the Real Grade Point Average (GPA), and propose as well an index for SET scores, the Real SET, to make inflated grades and inflated SET scores more visible. Used by institutions, parts of institutions or individual faculty, Real GPA and Real SET would encourage and protect faculty and students who offer or seek out educational experiences that have not been deflected by greed, sloth or cowardice.
My life on Mt Olympus

Purpose – The purpose of this paper is to recount Stanley C. Hollander's own educational experiences and career paths. This is a reprint (with permission) of Stanley C. Hollander's article which first appeared in the Journal of Macromarketing in 1995.Design/methodology/approach – An autobiographical description of the author's early years.Findings – The paper reveals many of Stanley C. Hollander's personal thoughts, reflections and some regrets.Originality/value – The paper provides valuable personal insights from the late Stanley C. Hollander.
Localized steady-state domain wall oscillators

The authors predict a spatially localized magnetic domain wall oscillator upon the application of an external magnetic field and a dc electric current. The amplitude and frequency of the oscillator can be controlled by the field and/or the current. The resulting oscillator could be used as an effective microwave source for information storage application.
The ghost of financing gap: testing the growth model used in the international financial institutions

Abstract The Harrod–Domar growth model supposedly died long ago. Still today, economists in the international financial institutions (IFIs) apply the Harrod–Domar model to calculate short-run investment requirements for a target growth rate. They then calculate a “financing gap” between the required investment and available resources and often fill the “financing gap” with foreign aid. The financing gap model has two simple predictions: (1) aid will go into investment one for one, and (2) there will be a fixed linear relationship between growth and investment in the short run. The data soundly reject these two predictions of the financing gap model.
An architecture for knowledge-based graphical interfaces

The construction of intelligent interfaces can be greatly facilitated by classifying the information that users and programs communicate, and by separating the user interface from the functionality of a program. This paper presents a scheme for classifying this information, and show how, by structuring the interface around this scheme, the user interface and functionality of a program can be separated, and tools can be built that provide assistance to both users and developers of user interfaces.
Can the master time asymmetry in nature be electrodynamic in origin

If the electrodynamic measurement process is operationally described by imposing measurement color onto classical electrodynamics, self-energy infinities are eliminated and a retarded electrodynamic time arrow emerges dynamically from internal dynamic-stability conditions. This occurs because the new formalism containsnonlocal radiation fields which carry anegative parity under mathematical time reversal. This result is shown to be compatible with an extended form ofT andCPT symmetry which preserves the dynamically chosen retarded electrodynamic arrow of time in the measurement color electrodynamic formalism.
Analysis of surface structural defects by low energy electron diffraction

Abstract The characterization of surface structural defects by low energy electron diffraction is discussed. The identification of crystal mosaic structure, random strain, antiphase domains and steps is emphasized, and it is shown that they produce characteristic effects in the angular distribution of intensity in diffracted beams. Analytical models are summarized. They are also applicable to other surface-sensitive diffraction techniques such as reflection high energy electron diffraction and grazing angle X-ray diffraction. The quantitative analysis of these several types of defects is illustrated by measurements on the surface of an epitaxially grown Ag(111) film and on a sputter-etched and annealed GaAs(110) surface.
A new approach to the challenge of machinery prognostics

Current generation mechanical diagnostic equipment is designed to identify individual events or trends in the output of sensors mounted on a mechanical component, subsystem, or system. Such equipment can provide a useful indication that a failure condition may be developing, but it cannot provide reliable prediction of the remaining safe or operational life. Typically, these diagnostic systems simply compare the output of individual sensors against a priori thresholds to establish a measure of the system's health. Two problems result from this approach: (1) There is no advantage taken of possible synergy among the sensors, i.e., the determination of health is one dimensional; and (2) the diagnosis provides only a statement regarding the current equipment health, but does not provide a prediction of the time remaining to failure. This often leads to an operational environment in which diagnostic equipment outputs are either ignored because of frequent false alarms or frequent (and costly) time-based preventive maintenance is performed to avoid hazardous failures. This paper describes a new approach to the development of a more robuts diagnosis and prognostic capability. It is based on the fusion of sensor-based and model-based information. Sensor-based information is the essence of current diagnostic systems. Model-based information combines dynamic models of individual components with micromechanical models of relevant failure mechanisms, such as fracture and crack propagation. These micromechanical models must account for initial flaw size ditribution and other microstructural parameters describing initial component condition. A specific application of this approach is addressed, the diagnosis of mechanical failure in meshing gears. Four specific issues are considered: (a) how to couple a validated numerical simulation of gear transmission error (due to tooth spacing irregularity, or material inhomogeneity) with physically and empirically based descriptions of fatigue crack grawth to predict a failure precursor signature at the component level; (b) how to predict the manifestation of this signature at the subsystem or system level where sensors are located; (c) how to fuse this model-based information with the corresponding sensor-based information to predict remaining safe or operational life of a gear; and (d) issues associated with extending this methodology to bearings and other rotating machinery components
Influence of Adsorbed Water on Exchangeable Ion Movement

The concept of activation energy for ion movement is discussed. It is shown that the activation energy for exchangeable ion movement is directly correlated with the specific volume of the adsorbed water, with the resistance to freezing of this water and with the activation energy for deuterium oxide diffusion in this water. Electrical interaction between ion and clay appears to have little effect on the activation energy. Consequently, it is concluded that the most important factor governing exchangeable ion movement in the pores of a clay-water system is the structure of the adsorbed water.
Musculoskeletal challenges of osteoporosis

Reduction in the biomechanical competence of the axial skeleton can result in challenging complications. Osteoporosis consists of a heterogeneous group of syndromes in which bone mass per unit volume is reduced in otherwise normal bone, which results in more fragile bone. The geriatric population has an increased risk for debilitating postural changes because of several factors. The two most apparent factors are involutional loss of functional muscle motor units and the greater prevalence of osteoporosis in this population. Obviously, the main objective of rehabilitation is to prevent fractures rather than to treat the complications. These complications can vary from "silent" compression fractures of vertebral bodies, to sacral insufficiency fractures, to "breath-taking" fractures of the spine or femoral neck. The exponential loss of bone at the postmenopausal stage is not accompanied by an incremental loss of muscle strength. The loss of muscle strength follows a more gradual course and is not affected significantly by a sudden hormonal decline, as is the case with bone loss. This muscle loss may contribute to osteoporosis-related skeletal disfigurations. In men and women, the combination of aging and reduction of physical activity can affect musculoskeletal health, and contribute to the development of bone fragility. The parallel decline in muscle mass and bone mass with age is more than a coincidence, and inactivity may explain some of the bone loss previously associated with aging per se. Kyphotic postural change is the most physically disfiguring and psychologically damaging effect of osteoporosis and can contribute to an increment in vertebral fractures and the risk of falling. Axial skeletal fractures, such as fracture of the sacral alae (sacral insufficiency fracture) and pubic rami, may not be found until radiographic changes are detected. Management of chronic pain should include not only improvement of muscle strength and posture but also, at times, reduction of weight bearing on the painful pelvis with insufficiency fractures. Axial skeletal health can be assisted with improvement of muscular supportive strength. Disproportionate weakness in the back extensor musculature relative to body weight or flexor strength considerably increases the risk of compressing porous vertebrae. A proper exercise program, especially osteogenic exercises, can improve musculoskeletal health in osteoporotic patients. Exercise not only improves musculoskeletal health but also can reduce the chronic pain syndrome and decrease depression. Application of a proper back support can decrease kyphotic posturing and can expedite the patient's return to ambulatory activities. Measures that can increase safety during ambulatory activities can reduce risk of falls and fractures. Managing the musculoskeletal challenges of osteoporosis goes hand in hand with managing the psychological aspects of the disease.
Arrival times in a zero-range process with injection and decay

Explicit expressions for arrival times of particles moving in a one-dimensional zero-range process (ZRP) are computed. Particles are fed into the ZRP from an injection site and can evaporate from any site of the one-dimensional lattice. Two dynamics are considered: bulk dynamics, where particle hopping and decay are proportional to the number of particles at each site, and surface dynamics, where only the top particle at each site can hop or evaporate. We find exact solutions in the bulk dynamics case and for a single-site ZRP obeying surface dynamics. For a multisite ZRP obeying surface dynamics, we compare simulations with approximations obtained from the steady-state limit, where mean interarrival times for both models are equivalent. Our results highlight the competition between injection and evaporation in the arrival times of particles to an absorbing site.
Efficient synthesis of 4-hydroxycyclopentenones: dysprosium(III) triflate catalyzed Piancatelli rearrangement

4-Hydroxycyclopentenones represent a privileged scaffold in chemical synthesis. A dysprosium(III) trifluoromethanesulfonate catalyzed rearrangement of furylcarbinols to 4-hydroxycyclopentenones via a 4π electrocyclization has been developed. The catalytic Piancatelli rearrangement affords a single trans-diastereomer from both aryl and alkyl substituted furylcarbinols.
MICROCALORIMETERS FOR X-RAY SPECTROSCOPY

The merits of microcalorimetry below 1 ° K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.l°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.
Vortices and a TQFT for Lefschetz fibrations on 4–manifolds

Adapting a construction of D. Salamon involving the U(1) vortex equations, we explore the properties of a Floer theory for 3–manifolds that fiber over S1 which exhibits several parallels with monopole Floer homology, and in all likelihood coincides with it. The theory fits into a restricted analogue of a TQFT in which the cobordisms are required to be equipped with Lefschetz fibrations, and has connections to the dynamics of surface symplec-
A technetium(V) complex resulting from intramolecular ring closure of a tridentate schiff base ligand. X-ray crystal structure of chlorobis( 2-(2-hydroxyphenyl)benzothiazolato)oxotechnetium(V)

Abstract The X-ray crystal structure of a new technetium(V) complex, chlorobis(2-(2-hydroxyphenyl)benzothiazolato)oxotechnetium(V), TcO(hbt)2Cl, is reported. Crystals of this complex were obtained from a dichloromethane solution containing predominately chloro [N-(2-mercaptophenyl)salicylideneiminato]-oxotechnetium(V), TcO(Sphsal)Cl. The new TcO(hbt)2Cl complex is presumably a minor product in the preparation of TcO(Sphsal)Cl; the bidentate hbt ligand is generated upon intramolecular ring closure of the tridentate Sphsal ligand. Single crystal X-ray structure analysis shows the TcO(hbt)2Cl complex to be six coordinate with two hbt ligands coordinating to a monooxo technetium(V) core through the phenolate oxygen atoms and the nitrogen atoms of the benzothiazole rings. One of the phenolate oxygen atoms is trans to the TcO linkage. The complex crystallizes in the monoclinic space group P21/n with a=13.288(6), b=16.12(2), c=13.64(1) A, β = 94.65(6)°, V=2912.05 A3 and Z=4. The structure has been refined to R=0.082 for 1978 observed reflections.
The Chandra Deep Field–North Survey and the cosmic X–ray background

Chandra has performed a 1.4 Ms survey centred on the Hubble Deep Field–North (HDF–N), probing the X–ray Universe 55–550 times deeper than was possible with pre–Chandra missions. We describe the detected point and extended X–ray sources and discuss their overall multi–wavelength (optical, infrared, submillimetre and radio) properties. Special attention is paid to the HDF–N X–ray sources, luminous infrared starburst galaxies, optically faint X–ray sources and high–to–extreme redshift active galactic nuclei. We also describe how stacking analyses have been used to probe the average X–ray–emission properties of normal and starburst galaxies at cosmologically interesting distances. Finally, we discuss plans to extend the survey and argue that a 5–10 Ms Chandra survey would lay key groundwork for future missions such as XEUS and Generation–X.
Understanding the agreements and controversies surrounding childhood psychopharmacology

The number of children in the US taking prescription drugs for emotional and behavioral disturbances is growing dramatically. This growth in the use of psychotropic drugs in pediatric populations has given rise to multiple controversies, ranging from concerns over off-label use and long-term safety to debates about the societal value and cultural meaning of pharmacological treatment of childhood behavioral and emotional disorders. This commentary summarizes the authors' eight main findings from the first of five workshops that seek to understand and produce descriptions of these controversies. The workshop series is convened by The Hastings Center, a bioethics research institute located in Garrison, New York, U.S.A.
What Determines the Size of Aid Projects

Summary Over the last few years, considerable attention has focused on aid fragmentation, the proliferation of donors and projects in developing countries. Aid fragmentation has continued to increase despite international efforts to foster donor coordination. One possible implication of fragmentation is smaller aid projects, potentially with the result of more administrative work for overtaxed recipient governments per dollar of aid received. This paper makes use of AidData data on bilateral aid commitments, sector, and funding agencies to explore the determinants of project size and to better understand the forces driving aid fragmentation. To the extent that project size is driven by the sectoral composition or purpose of aid, the associated administrative costs may be justified. Variations due to other factors, e.g. a donor’s administrative structure or bureaucratic interests, provide a stronger case for reforms.
On the finite field Kakeya problem in two dimensions

Abstract A two-dimensional Besicovitch set over a finite field is a subset of the finite plane containing a line in each direction. In this paper, we conjecture a sharp lower bound for the size of such a subset and prove some results toward this conjecture.
Thermal Phenomena in Nanoscale Transistors

As CMOS transistor gate lengths are scaled below 45 nm, thermal device design is becoming an important part of microprocessor engineering. Decreasing dimensions lead to nanometer-scale hot spots in the drain region of the device, which may increase the drain series and source injection electrical resistances. Such trends are accelerated with the introduction of novel materials and nontraditional transistor geometries, like ultrathin body, surround-gate, or nanowire devices, which impede heat conduction. Thermal analysis is complicated by subcontinuum phenomenan including ballistic electron transport, which reshapes the hot spot region compared with classical diffusion theory predictions. Ballistic phonon transport from the hot spot and between material boundaries impedes conduction cooling. The increased surface to volume ratio of novel transistor designs also leads to a larger contribution from material boundary thermal resistance. In this paper we survey trends in transistor geometries and materials, from bulk silicon to carbon nanotubes, along with their implications for the thermal design of electronic systems.
QCD thermodynamics from the lattice

We review the current methods and results of lattice simulations of quantum chromodynamics at nonzero temperatures and densities. The review is intended to introduce the subject to interested nonspecialists and beginners. It includes a brief overview of lattice gauge theory, a discussion of the determination of the crossover temperature, the QCD phase diagram at zero and nonzero densities, the equation of state, some in-medium properties of hadrons including charmonium, and some plasma transport coefficients.
Catalytic asymmetric alkylation of substituted isoflavanones.

The asymmetric alkylation of isoflavanones (3-aryl-chroman-4-ones) and protected 3-phenyl-2,3-dihydroquinolin-4(1H)-ones catalyzed by a novel cinchonidine-derived phase transfer catalyst E is reported. This functionalization occurs at the unactivated C3 methine to afford novel products that can easily be functionalized to generate more complex fused ring systems. The process accommodates a variety of isoflavanones and activated electrophiles and installs a stereogenic quaternary center in high yield and with good-to-excellent selectivity. Isoflavanones are a privileged class of natural products with a broad spectrum of biological activities including insecticidal, antimicrobial, antibacterial, estrogenic, antitumor, and anti-HIV activity.(1) Isoflavanones are also precursors for more complex natural products such as pterocarpans and rotenones.(1) Given their therapeutic promise, selective strategies to access new classes of isoflavanones and related structures has high value.(2) The functionalization of t...
Large diffraction gratings ruled on a commercial measuring machine controlled interferometrically

The carriage and ways of a Moore No. 3 measuring machine were slightly modified, and to them were added monorail, diamond carriage, and suitable drive and gearing. When placed under interferometric control, the resulting ruling engine produces excellent gratings of previously unattained dimensions. A stabilized laser removes cumulative and periodic screw errors through blank translation control, and through yaw control eliminates fanning that otherwise would result from way curvature. Blanks up to 260×430 mm can be ruled. A number of echelles in sizes up to 210×410 mm (8×16 in.) have been ruled on this B engine at spacings of 10 fringes (316 grooves/mm) and 40 fringes, and at blaze angles from 62° to 79°. Many of these show the high resolving power and freedom from both error of run and Rowland-ghosts characteristic of echelles from the M.I.T. A engine, with satellites, ghosts of all types, and scattered light reduced further in intensity by 1 to 2 orders of magnitude. Still larger gratings are being ruled on the M.I.T. C engine, of capacity 450×635 mm, based on a Moore No. 4 measuring machine, which is now being improved from grating to echelle ruling quality.
Recent developments in discrete torsion

Abstract In this Letter we briefly review some recent developments in understanding discrete torsion. Specifically, we give a short overview of the highlights of a group of recent papers which give the basic understanding of discrete torsion. Briefly, those papers observe that discrete torsion can be completely understand simply as the choice of action of the orbifold group on the B field. We summarize the main points of that work.
Determinants of foster care placement for the maltreated child.

This study examined the records of the North Carolina Central Registry of Child Abuse and Neglect to determine which social, family, and child characteristics were most influential in the decision to place a child in foster care. These records contained all theoretically relevant factors as well as demographic data. Analysis included the computation of odds ratios for foster care for each of 250 variables. A maximum likelihood logistic regression model was constructed to obtain the independent and cumulative contribution of each factor. Some expected variables such as parental stress factors (substance abuse) and types of abuse (burns and scalds) placed a child at a significant risk for placement in foster care (p less than 0.01). However, less obvious factors such as referral source (law enforcement agencies) or geographic area also placed children at risk. Overall, the model explained little of the variance of these decisions (R2 = 0.168) and poorly predicted placement (sensitivity 66.3 per cent, specificity 74.6 per cent). Using existing data, we were unable to adequately describe the decision process in selecting foster care. Language: en
Palladium-Catalyzed Cyclization of 1-Iodo-Substituted 1,4-, 1,5-, and 1,6-Dienes as Well as of 5-Iodo-1,5-dienes in the Presence of Carbon Monoxide

A series of ω-alkene-containing alkenyl iodides were prepared via (a) various allyl-, homoallyl-, and higher ω-alkenylmetalation reactions of alkynes involving Zn, Al−Zr, Zn−Zr, and Cu, (b) trans-hydroalumination and Cu-catalyzed trans-carbomagnesiation of propargyl alcohols, and (c) Zr-promoted alkyne−alkene coupling. Various factors affecting three cyclic acylpalladation (Types I−III Ac-Pd) and three cyclic carbopalladation (Types I−III C-Pd) processes of the ω-alkene-containing alkenyl iodides under the influence of CO and Pd−phosphine catalysts have been delineated. In the presence of methanol or other alcohols at relatively high pressures (30−100 atm) of CO (Conditions IV), Type II Ac-Pd products containing five-membered ketones, such as 22, 26−28, 30, and 32, can be obtained generally in high yields. The order of rates of various carbonylative cyclization reactions producing five-membered rings is as follows: lactonization > Type II Ac-Pd reaction > C-enolate trapping with malonate anion. The prepa...
Finding minimum-cost circulations by canceling negative cycles

A classical algorithm for finding a minimum-cost circulation consists of repeatedly finding a residual cycle of negative cost and canceling it by pushing enough flow around the cycle to saturate an arc. We show that a judicious choice of cycles for canceling leads to a polynomial bound on the number of iterations in this algorithm. This gives a very simple strongly polynomial algorithm that uses no scaling. A variant of the algorithm that uses dynamic trees runs in O(nm(log n)min{log(nC), m log n}) time on a network of n vertices, m arcs, and arc costs of maximum absolute value C. This bound is comparable to those of the fastest previously known algorithms.
Modularity and anti-modularity in networks with arbitrary degree distribution

Background Much work in systems biology, but also in the analysis of social network and communication and transport infrastructure, involves an in-depth analysis of local and global properties of those networks, and how these properties relate to the function of the network within the integrated system. Most often, systematic controls for such networks are difficult to obtain, because the features of the network under study are thought to be germane to that function. In most such cases, a surrogate network that carries any or all of the features under consideration, while created artificially and in the absence of any selective pressure relating to the function of the network being studied, would be of considerable interest.
Election closeness and voter turnout: Evidence from California ballot propositions

This paper uses a new data set of 885 California ballot propositions from 1912 through 1990 to test the hypothesis that voter turnout increases as an election becomes closer. Various measures of voter participation are regressed on various measures of election closeness. The main finding is that there is not a systematic relation between closeness and turnout. Two conclusions are drawn: (1) voters are not sensitive to the probability their votes are decisive, and (2) other studies which found higher turnout for close elections probably detected an increased mobilization of party elites in tight races.
Segregation and Strategic Neighborhood Interaction

We introduce social interactions into the Schelling model of residential choice; these interactions take the form of a Prisoner's Dilemma game. We first study a Schelling model and a spatial Prisoner's Dilemma model separately to provide benchmarks for studying a combined model, with preferences over like-typed neighbors and payoffs in the spatial Prisoner's Dilemma game. We find that the presence of these additional social interactions may increase or decrease segregation compared to the standard Schelling model. If the social interactions result in cooperation then segregation is reduced, otherwise it can be increased.
A devastating example for the Halfer Rule

How should we update de dicto beliefs in the face of de se evidence? The Sleeping Beauty problem divides philosophers into two camps, halfers and thirders. But there is some disagreement among halfers about how their position should generalize to other examples. A full generalization is not always given; one notable exception is the Halfer Rule, under which the agent updates her uncentered beliefs based on only the uncentered part of her evidence. In this brief article, I provide a simple example for which the Halfer Rule prescribes credences that, I argue, cannot be reasonably held by anyone. In particular, these credences constitute an egregious violation of the Reflection Principle. I then discuss the consequences for halfing in general.
Income effects and indeterminacy in a calibrated one-sector growth model

Abstract This note analyzes how the indeterminacy of competitive equilibrium in one-sector growth models depends on the magnitude of the households' income effect on the demand for leisure. Since I am interested in quantitatively characterizing regions of indeterminacy, I use the Jaimovich and Rebelo [N. Jaimovich, S. Rebelo, Can news about the future drive the business cycle? Mimeo, Northwestern University, 2007] preferences that span a wide range of income effect values. I find that indeterminacy can occur for levels of aggregate-returns-to-scale that are well within recent empirical estimates. For these regions of indeterminacy, the model, when driven solely by sunspot shocks, generates second-moment properties that are consistent with the U.S. data at the business cycle frequency.