cssi/SciSciGPT-SciSciNet huggingface dataset:
Africa's infrastructure : a time for transformation

This study is part of the Africa Infrastructure Country Diagnostic (AICD), a project designed to expand the world's knowledge of physical infrastructure in Africa. The AICD will provide a baseline against which future improvements in infrastructure services can be measured, making it possible to monitor the results achieved from donor support. It should also provide a more solid empirical foundation for prioritizing investments and designing policy reforms in the infrastructure sectors in Africa. The AICD is based on an unprecedented effort to collect detailed economic and technical data on the infrastructure sectors in Africa. The project has produced a series of original reports on public expenditure, spending needs, and sector performance in each of the main infrastructure sectors, including energy, information and communication technologies, irrigation, transport, and water and sanitation. The first phase of the AICD focused on 24 countries that together account for 85 percent of the gross domestic product, population, and infrastructure aid flows of Sub-Saharan Africa. Under a second phase of the project, coverage is expanding to include as many of the additional African countries as possible.
Microbial diversity and activity in the Nematostella vectensis holobiont: insights from 16S rRNA gene sequencing, isolate genomes, and a pilot-scale survey of gene expression.

We have characterized the molecular and genomic diversity of the microbiota of the starlet sea anemone Nematostella vectensis, a cnidarian model for comparative developmental and functional biology and a year-round inhabitant of temperate salt marshes. Molecular phylogenetic analysis of 16S rRNA gene clone libraries revealed four ribotypes associated with N. vectensis at multiple locations and times. These associates include two novel ribotypes within the e-Proteobacterial order Campylobacterales and the Spirochetes, respectively, each sharing 99% 16S rRNA identity with Endozoicomonas elysicola and Pseudomonas oleovorans, respectively. Species-specific PCR revealed that these populations persisted in N. vectensis asexually propagated under laboratory conditions. cDNA indicated expression of the Campylobacterales and Endozoicomonas 16S rRNA in anemones from Sippewissett Marsh, MA. A collection of bacteria from laboratory raised N. vectensis was dominated by isolates from P. oleovorans and Rhizobium radiobacter. Isolates from field-collected anemones revealed an association with Limnobacter and Stappia isolates. Genomic DNA sequencing was carried out on 10 cultured bacterial isolates representing field- and laboratory-associates, i.e., Limnobacter spp., Stappia spp., P. oleovorans and R. radiobacter. Genomes contained multiple genes identified as virulence (host-association) factors while S. stellulata and L. thiooxidans genomes revealed pathways for mixotrophic sulfur oxidation. A pilot metatranscriptome of laboratory-raised N. vectensis was compared to the isolate genomes and indicated expression of ORFs from L. thiooxidans with predicted functions of motility, nutrient scavenging (Fe and P), polyhydroxyalkanoate synthesis for carbon storage, and selective permeability (porins). We hypothesize that such activities may mediate acclimation and persistence of bacteria in a N. vectensis holobiont defined by both internal and external gradients of chemicals and nutrients in a dynamic coastal habitat.
Impact of Liquidity on the Futures‐Cash Basis: Evidence from the Indian Market

Arbitragers’ activities are constrained by market liquidity. In turn, arbitrage activity may trigger order imbalances adversely affecting liquidity. We examine this issue by analyzing the link between the futures-cash basis and bid–ask spreads using intraday data on single stock futures (SSFs) contracts on Indian stocks. In contrast to other countries, the SSF market in India is very active due to retail investors’ prior experience with the badla system, a form of forward markets. The analysis reveals two-way Granger causality between the basis and spreads in both the futures and cash markets. Evidence for spreads Granger-causing basis is stronger for stocks with higher volume and SSFs that are relatively more active than underlying stocks. © 2012 Wiley Periodicals, Inc. Jrl Fut Mark 33:266–298, 2013
Feynman–Kac formulas for regime-switching jump diffusions and their applications

This work develops Feynman–Kac formulas for a class of regime-switching jump diffusion processes, in which the jump part is driven by a Poisson random measure associated with a general Levy process and the switching part depends on the jump diffusion processes. Under broad conditions, the connections of such stochastic processes and the corresponding partial integro-differential equations are established. Related initial, terminal and boundary value problems are also treated. Moreover, based on weak convergence of probability measures, it is demonstrated that a sequence of random variables related to the regime-switching jump diffusion process converges in distribution to the arcsine law.
The effect of large-scale structure on the magnification of high-redshift sources by cluster lenses

Cluster gravitational lensing surveys like the Hubble Space Telescope Frontier Fields survey will detect distant galaxies 10-50 times fainter than any yet discovered. Using these surveys to measure the luminosity function of such faint, distant galaxies, however, requires that magnification maps built from the constraints of strongly-lensed images be accurate. For models that assume the cluster and nearby (correlated) structures are the only significant sources of lensing, a potential source of error in these maps comes from the fact that light rays also suffer weak deflections by uncorrelated large-scale structure along the line-of-sight, i.e. cosmic weak lensing (CWL). To demonstrate the magnitude of this effect, we calculate the magnification change which results when the same cluster-lens is placed along different lines of sight. Using a simple density profile for a cluster-lens at z~0.3-0.5 and the power spectrum of the matter density fluctuations responsible for CWL, we show that the typical magnifications of ~5(10) of sources at z=6-10 can differ by ~10-20(20-30)% from one line-of-sight to another. However, these fluctuations rise to greater than order unity near critical curves, indicating that CWL tends to make its greatest contribution to the most magnified images. We conclude that the neglect of CWL in determining the intrinsic luminosities of highly-magnified galaxies may introduce errors significant enough to warrant further effort to include this contribution in cluster-lens modeling. We suggest that methods of modeling CWL in galaxy-strong-lensing systems should be generalized to cluster-lensing systems.
Wide-field wide-band Interferometric Imaging: The WB A-Projection and Hybrid Algorithms

Variations of the antenna primary beam (PB) pattern as a function of time, frequency, and polarization form one of the dominant direction-dependent effects at most radio frequency bands. These gains may also vary from antenna to antenna. The A-Projection algorithm, published earlier, accounts for the effects of the narrow-band antenna PB in full polarization. In this paper, we present the wide-band A-Projection algorithm (WB A-Projection) to include the effects of wide bandwidth in the A-term itself and show that the resulting algorithm simultaneously corrects for the time, frequency, and polarization dependence of the PB. We discuss the combination of the WB A-Projection and the multi-term multi-frequency synthesis (MT-MFS) algorithm for simultaneous mapping of the sky brightness distribution and the spectral index distribution across a wide field of view. We also discuss the use of the narrow-band A-Projection algorithm in hybrid imaging schemes that account for the frequency dependence of the PB in the image domain.
Studies of mild dehydrogenations in heterocyclic systems

Abstract The use of bromotrichloromethane-DBU is described for the selective oxidative conversion of several dihydro-heterocyclic systems to the corresponding heteroaromatics. Oxidative dehydrogenations to afford 4-hydroxy-2-pyridinones are examined under a variety of conditions. Studies of phenylselenenylation and peracid oxidation provide the novel spirocyclic oxirane 10 .
Radiosynthesis of [11C]Vandetanib and [11C]chloro-Vandetanib as new potential PET agents for imaging of VEGFR in cancer.

Abstract Vandetanib (ZD6474) and its chlorine analogue chloro-Vandetanib are potent and selective vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors with low nanomolar IC50 values. [11C]Vandetanib and [11C]chloro-Vandetanib, new potential PET agents for imaging of VEGFR in cancer, were first designed, synthesized and labeled at nitrogen and oxygen positions from their corresponding N- and O-des-methylated precursors, in 40–50% decay corrected radiochemical yield and 370–555 GBq/μmol specific activity at end of bombardment (EOB).
Viterbi-Based Efficient Test Data Compression

This paper presents a Viterbi-based test compression algorithm/architecture that provides high encoding efficiency and scalability with respect to the number of test channels. The proposed scheme finds a set of compressed test vectors using the Viterbi algorithm instead of solving linear equations. By assigning a cost function to the branch metric of the Viterbi algorithm, an optimal compressed vector is selected among the possible solution set. This feature enables high flexibility to combine various test requirements such as low-power compression and/or improving capability to repeat test patterns. The proposed on-chip decompressor follows the structure of Viterbi encoders which require only one input channel. Experimental results on test volume show improvement on all ISCAS89 benchmark circuits (19.32% reduction on the average) compared to previous test data compression architectures. The proposed scheme also yields efficient power-dissipation/volume tradeoff.
The effective cone of the space of parametrized rational curves in a Grassmannian

We determine the effective cone of the Quot scheme parametrizing all rank r, degree d quotient sheaves of the trivial bundle of rank n on $${\mathbb{P}^1}$$ . More specifically, we explicitly construct two effective divisors which span the effective cone, and we also express their classes in the Picard group in terms of a known basis.
Wide Stiffness Range Cavity Optomechanical Sensors for Atomic Force Microscopy

We present chip-based sensors that integrate nanomechanical cantilevers with near-field optical readout for atomic force microscopy. Cantilever stiffness is varied over four orders of magnitude while maintaining fm/Hz^(1/2) displacement sensitivity, indicating potential in wide-ranging applications.
Hydrolysis of Iminium Ethers Derived from the Reaction of Ketones with Hydroxy Azides: Synthesis of Macrocyclic Lactams and Lactones

The hydrolysis of iminium ether intermediates formed by a nitrogen insertion sequence involving azido alcohols 1 or 2 and ketones was investigated. Ketones containing 6−12-membered rings were surveyed and shown to provide lactams and lactones in good to excellent overall yield. Reactions employing acetone or 5-nonanone gave similar results, generating analogous amides and esters. The relative amounts of lactone vs lactam produced in a given reaction were found to depend on the structures of the reactants and the pH of the basic media used to hydrolyze the iminium ethers. A mechanism accounting for the formation of each product is discussed in terms of ring strain and the protonation state of ortho ester aminal intermediates.
Scattering and transmission matrices of partially polarized radiation in a Rayleigh atmosphere bounded by a specular reflector

In a manner similar to that given in a preceding paper (cf. Castiet al., 1970), in this paper we show how to get a Cauchy system for the scattering and transmission matrices of the azimuth-independent term of partially polarized light in accordance with Rayleigh scattering in a homogeneous atmosphere bounded by a specular reflector. This set of integro-differential equations for the scattering and transmission matrices is suitable for numerical computation by high-speed digital computer.
New York Milk Supply with Bovine Growth Hormone

New York milk supply functions with and without bovine growth hormone (somatotropin) were estimated by a sector linear programming model. High government price supports make bGH profitable and induce significant increases in output. Reduction or elimination of price supports greatly diminishes bGH as a viable technology except with high-producing herds or at low bGH prices.
Synthesis of para-Substituted 1,4,5,6,7,7-Hexachlorobicyclo- (2.2.1)hepta-2,5-dien-2-ylmethyl Benzoates

[4 + 2]-Cycloaddition of hexachlorocyclopentadiene to para-substituted prop-2-yn-1-yl benzoates gave the corresponding 1,4,5,6,7,7-hexachlorobicyclo[2.2.1]hepta-2,5-dien-2-ylmethyl benzoates. The structure of the adducts was confirmed by independent synthesis, esterification of para-substituted benzoic acids with 1,4,5,6,7,7-hexachlorobicyclo[2.2.1]hepta-2,5-dien-2-ylmethanol.
Ion implantation effects in crystalline quartz

Abstract Cantilever beam measurements of the stress induced in crystalline quartz by implantation of 150 keV Ar and/or 250 keV He have shown that the data scale with energy into collisional processes. The damage state induced by the Ar implants does not lend itself to efficient utilization of the electronic component of subsequent He implantation in producing further disorder. The damage depth has been measured (optically) for a number of ions (1 × 10 16 250 keV/cm 2 ) and has been found to vary (relative to TRIM values) from about 0.63 R p for He to about 1.84 R p for Xe. RBS measurements of range for Ar to Au give values in fair agreement with the optical values. The ratio of the measured (optical) ranges to the predicted (TRIM) ranges, when plotted as a function of collisional energy deposition, indicates that extended damage (beyond ion range) occurs for deposition energies > ~ 1 x 10 22 keV/cm 3 . The damage persists even after 900 ° C anneals. The effects of ion-induced stress may be an important factor in the establishment of the extended damage state.
Rotating ring-disk study of the oscillating electrochemical reaction of iodide at gold

Abstract The ring electrode of a Au–Au rotating ring-disk electrode was used to monitor the concentrations of I − and I 2 during oscillations in current that occur during I − oxidation at the disk electrode. With the ring electrode poised at a potential sufficient to oxidize I − , the anodic current at the ring decreased, while the anodic current at the disk increased, as was expected for a typical shielding experiment. However, when the ring was poised at a potential sufficient to reduce I 2 (or I 3 − ) in a collection experiment, the cathodic current also decreased simultaneously with the increase in anodic current at the disk. These results demonstrate convincingly that the oscillating current involves the periodic formation and dissolution of an I 2 film.
Job Stress and Preeclampsia

We conducted a case-control study to determine whether job strain (or stress) during pregnancy resulted in an increased risk of preeclampsia. We compared 110 nulliparous Caucasian and African-American women who had preeclampsia with 115 healthy nulliparous controls. All subjects gave birth between 1984 and 1987 in Chapel Hill, NC. Occupation was ascertained during a telephone interview. We assigned each job title a strain (or stress) score in accordance with the occupational database developed by Karasek. Overall, 54 (49%) of the control women worked during pregnancy, 14 in high-stress jobs. Logistic regression analysis indicated a 3.1-fold [95% confidence interval (CI) = 1.2-7.8] increased risk of preeclampsia for women employed in high-stress jobs (high psychological demand, low decision latitude) and an odds ratio of 2.0 (95% CI = 1.0-4.3) for low-stress jobs compared with nonworking women, while simultaneously adjusting for age, race, family history of preeclampsia, history of hypertension in the subject's mother, gravidity, smoking during pregnancy, timing of the first prenatal visit, and type of birth control used by the couple before the pregnancy. Furthermore, working women had 2.3 times the risk of developing preeclampsia (95% CI = 1.2-4.6) compared with nonworking women. Work-related psychosocial strain increased the risk of preeclampsia in our study.
Comparison of the relative stabilities of polycyclic aryl nitrenium ions and arylmethyl cations: ab initio and semiempirical molecular orbital calculations

Abstract Ab initio HF/3-21G calculations predict the stabilities of a series of nitrenium ions to increase in the order, phenyl
Observations of Global and Local Infall in NGC 1333

We report "infall asymmetry" in the HCO+(1-0) and (3-2) lines toward NGC 1333, extended over ~0.39 pc2, a larger extent than has been reported before for any star-forming region. The infall asymmetry extends over a major portion of the star-forming complex, and is not limited to a single protostar, a single dense core, or a single spectral line. It seems likely that the infall asymmetry represents inward motions, and that these motions are physically associated with the complex. Both blue-asymmetric and red-asymmetric lines are seen, but in both the (3-2) and (1-0) lines of HCO+ the vast majority of the asymmetric lines are blue, indicating inward motions. The (3-2) line, tracing denser gas, has the spectra with the strongest asymmetry; these spectra are associated with the protostars IRAS 4A and 4B, which most likely indicates that a warm central source is affecting the line profiles. The (3-2) and (1-0) lines usually have the same sense of asymmetry in common positions, but their profiles differ significantly, and the (1-0) line appears to trace motions on much larger spatial scales than does the (3-2) line. Line profile models fit the spectra well, but do not strongly constrain their parameters. The mass accretion rate of the inward motions is of order 10-4 M☉ yr-1, similar to the ratio of stellar mass to cluster age.
The synthesis and reactions of 4-(2- and 3-thienyl)-tetrahydroisoquinolines

Tetrahydroisoquinoline derivatives substituted in the 4-position by either a 2- or 3-substituted thiophene ring have been synthesised. Simple electrophilic substitution reactions of these systems take place as expected in the α-position of the thiophene ring. Metalation reactions are more complex and take place at the benzylic 4-position of the tetrahydroisoquinoline nucleus in the case of the 2-substituted thiophene derivatives or at either the thiophene α-positions or the benzylic 4-position depending on the nature of the attacking electrophile in the case of the 3-substituted thiophene system.
National Settings and Public Enterprise: Australia and Israel*

: There are sharp differences between the public enterprises of Australia and Israel. Australia relies on the structure of statutory authorities for enterprises of the Commonwealth and the States; managers express a narrow view of what is permitted to them; and tend to spend their careers within single firms. “Public” enterprise in Israel reflects a complex amalgam of three public sectors, with Arms owned wholly or in part by the State, the labour federation, and institutions of the international Jewish community. Israel emphasizes the more flexible structure of public sector holdings in limited liability companies. Entrepreneurialism is more apparent in the public enterprises of Israel than Australia, but problems of service delivery are also more apparent in Israel. This article relates national differences in enterprise traits of control by government, styles of management, career patterns and service delivery to the national settings of government structure, economics, and political culture.
Time Rates of Generalized Strain Tensors. Part 1. Component Formulas

Abstract Hill derived a simple component formula for the material time derivative of a generalized Lagrangian strain tensor. We examine Hill's derivation in detail and explain why it is generally valid only when the principal stretches are distinct. We then give a proof of Hill's formula which is valid for any C 2 motion and any C l strain measure. Our proof is based on a component form of the chain rule for a tensor-valued function of a time-dependent symmetric tensor. This result is also used to derive component formulas for the Jaumann rate of a generalized Eulerian strain tensor. Finally, we apply the general formulas to the logarithmic strain tensors.
Time reversal symmetry breaking effects in resonant nuclear reactions

We incorporate time reversal symmetry breaking (TRSB) effects into the theory of compound nuclear reactions. We show that the only meaningful test of TRSB in the overlapping resonances regime is through the study of cross-section correlations. The effect is channel-dependent. In the isolated resonance regime, we employK-matrix theory to show the impact of TRSB using the fact that when only one eigen-channel participates in populating and depopulating the compound resonance.
Improved deprotection of cysteine‐containing peptides in HF

The deprotection of S-4-methylbenzyl-cysteine in HF was studied as a function of acidity and scavengers employed and a highly effective procedure was developed. Under conditions of low acidity which promote SN2 deprotection of benzyl alcohol-derived protecting groups of amino acid side-chain functionalities, i.e. low HF (HF:DMS, 1:3, v/v), little or no deprotection of S-4-methylbenzyl cysteine was observed. Under conditions of high acidity (90% HF), recovery of cysteine was only 79% using the conventional scavenger, anisole. However a combination of the scavengers p-cresol and p-thiocresol provided nearly quantitative recovery of the cysteine thiol, with the preferred deprotection conditions being HF:p-cresol:p-thiocresol (90:5:5, v/v), 0°C, 1 h. The possibility that the sulfoxide of the protected cysteine thioether was involved in cysteine side reactions was investigated. The formation of the sulfoxide was found to be low (0.15% per residue added) under standard solid-phase peptide synthesis conditions. Since the sulfoxide derivative was resistant to deprotection in high HF, two methods for the reduction of the molecule to the thioether were developed. One method involved the reduction of the sulfoxide in HF at intermediate acidity levels (HF:DMS, 40:60, v/v), 0°, 4h. The other method involved a mixture of TFA, DMS and CH2Cl2 (45:10:45, v/v) containing (Et)4 NCl ˜ H2O (50 equiv. per cysteine residue) which efficiently reduced both free and resin-bound S-4-methylbenzyl cysteine sulfoxide (t1/2= 35 min). Both methods also reduced methionine sulfoxide to methionine.
Moment maps and Riemannian symmetric pairs

We study Hamiltonian actions of a compact Lie group on a symplectic manifold in the presence of an involution on the group and an antisymplectic involution on the manifold. The fixed-point set of the involution on the manifold is a Lagrangian submanifold. We investigate its image under the moment map and conclude that the intersection with the Weyl chamber is an easily described subpolytope of the Kirwan polytope. Of special interest is the integral Kahler case, where much stronger results hold. In particular, we obtain convexity theorems for closures of orbits of the noncompact dual group (in the sense of the theory of symmetric pairs). In the abelian case these results were obtained earlier by Duistermaat. We derive explicit inequalities for polytopes associated with real flag varieties.
Scalable Attestation: A Step Toward Secure and Trusted Clouds

In this work we present Scalable Attestation, a method which combines both secure boot and trusted boot technologies, and extends them up into the host, its programs, and up into the guest's operating system and workloads, to both detect and prevent integrity attacks. Anchored in hardware, this integrity appraisal and attestation protects persistent data (files) from remote attack, even if the attack is root privileged. As an added benefit of a hardware rooted attestation, we gain a simple hardware based geolocation attestation to help enforce regulatory requirements. This design is implemented in multiple cloud test beds based on the QEMU/KVM hypervisor, Open Stack, and Open Attestation, and is shown to provide significant additional integrity protection at negligible cost.
Ketonization of Carboxylic Acids: Mechanisms, Catalysts, and Implications for Biomass Conversion

Ketonization is a reaction in which two carboxylic acids convert into a ketone, carbon dioxide, and water. While this reaction once found its industrial application for acetone production, it is regaining interest for its value in the upgrading of biomass-derived oxygenates, for example, bio-oils obtained from the fast pyrolysis of biomass. Namely, ketonization is crucial to reduce the detrimental effects of carboxylic acids in bio-oil. This review addresses reaction mechanisms, families of materials that catalyze the reaction (metal oxides and zeolites), and current applications of ketonization in the upgrading of biomass-derived oxygenates. A variety of mechanisms have been proposed to explain the ketonization reaction, and these proposals are critically discussed. The role of the α-hydrogen has been proven as a critical requirement for ketonization over catalysts that are active for surface ketonization and serves as the initial basis for the discussion. The role of crucial reaction intermediates such ...
Development of a coherent transition radiation-based bunch length monitor with application to the APS RF thermionic gun beam optimization☆

Abstract We report further development of an EPICS-compatible bunch length monitor based on the autocorrelation of coherent transition radiation (CTR). In this case the monitor was used to optimize the beam from the S-band thermionic RF gun on the Advanced Photon Source (APS) linac. Bunch lengths of 400–500 fs (FWHM) were measured in the core of the beam, which corresponded to about 100-A peak current in each micropulse. The dependence of the CTR signal on the square of the beam charge for the beam core was demonstrated. We also report the first use of the beam accelerated to 217 MeV for successful visible wavelength SASE FEL experiments.
Conversion of meso-alkenes to chiral alkenes via titanocene-catalyzed ring-opening/ring-closing olefin metathesis

Abstract The preparation of 7-anti-(3-methyl-3-butenyl)norbornene 11 is described. This meso-symmetrical diene underwent ring-opening/ring-closing olefin metathesis catalyzed by bis(cyclopentadienyl)titanacyclobutane 4 to give (1R ∗ , 6R ∗ , 7S ∗ ) -7-ethenyl-3-methylbicyclo[4.3.0]non-2-ene as a single diastereomer. The less-substituted 7-anti-(3-butenyl)norbornene 1 did not react selectively at the norbornene double bond. Related 7-ester-substituted norbornenes underwent stoichiometric ring-opening/ring-closing olefin metathesis to give single diastereomers of bicyclic ketones after acidic work-up. Attempts to form a chiral Tebbe-type complex from ansa-{2,2′-bis[8-(bicyclo[4.3.0]-nona-1(6),7-dienyl)]-1,1′-binaphthyl}titanium dichloride 18 or a reactive chiral titanium carbene intermediate from its dimethyl derivative 20 were unsuccessful.
Applying centrality measures to impact analysis: A coauthorship network analysis

Many studies on coauthorship networks focus on network topology and network statistical mechanics. This article takes a different approach by studying micro-level network properties with the aim of applying centrality measures to impact analysis. Using coauthorship data from 16 journals in the field of library and information science (LIS) with a time span of 20 years (1988–2007), we construct an evolving coauthorship network and calculate four centrality measures (closeness centrality, betweenness centrality, degree centrality, and PageRank) for authors in this network. We find that the four centrality measures are significantly correlated with citation counts. We also discuss the usability of centrality measures in author ranking and suggest that centrality measures can be useful indicators for impact analysis. © 2009 Wiley Periodicals, Inc.
Decision Making Times in Mean-Field Dynamic Ising Model

We consider a dynamic mean-field ferromagnetic model in the low-temperature regime in the neighborhood of the zero magnetization state. We study the random time it takes for the system to make a decision, i.e., to exit the neighborhood of the unstable equilibrium and approach one of the two stable equilibrium points. We prove a limit theorem for the distribution of this random time in the thermodynamic limit.
Ultra-high quality factors in superconducting niobium cavities in ambient magnetic fields up to 190 mG

Ambient magnetic field, if trapped in the penetration depth, leads to the residual resistance and therefore sets the limit for the achievable quality factors in superconducting niobium resonators for particle accelerators. Here, we show that a complete expulsion of the magnetic flux can be performed and leads to: (1) record quality factors Q > 2 × 1011 up to accelerating gradient of 22 MV/m; (2) Q ∼ 3 × 1010 at 2 K and 16 MV/m in up to 190 mG magnetic fields. This is achieved by large thermal gradients at the normal/superconducting phase front during the cooldown. Our findings open up a way to ultra-high quality factors at low temperatures and show an alternative to the sophisticated magnetic shielding implemented in modern superconducting accelerators.
Pentagons: A weakly relational abstract domain for the efficient validation of array accesses

We introduce Pentagons (Pntg), a weakly relational numerical abstract domain useful for the validation of array accesses in byte-code and intermediate languages (IL). This abstract domain captures properties of the form of x@?[a,b]@?x
A General and Enantioselective Approach to Pentoses: A Rapid Synthesis of PSI-6130, the Nucleoside Core of Sofosbuvir

An efficient route towards biologically relevant pentose derivatives is described. The de novo synthetic strategy features an enantioselective α-oxidation reaction enabled by a chiral amine in conjunction with copper(II) catalysis. A subsequent Mukaiyama aldol coupling allows for the incorporation of a wide array of modular two-carbon fragments. Lactone intermediates accessed via this route provide a useful platform for elaboration, as demonstrated by the preparation of a variety of C-nucleosides and fluorinated pentoses. Finally, this work has facilitated expedient syntheses of pharmaceutically active compounds currently in clinical use.
Maxims for the third resource conservation act appraisal

Abstract The paper explores three issues in the development of an ecological economics approach to the USDA's Third Resource Conservation Act (RCA) Appraisal. First, profit-maximizing farmers respond to incentives provided by both the USDA and the EPA, implying that explicit interagency policy strategies are critical. Second, evaluating sustainable agriculture options with the Appraisal can improve our understanding of the attractiveness of widespread adoption, but only if systematic operational systems are developed to evaluate the economic and environmental trade-offs. Third, the Appraisal policy options should be evaluated in light of the argument that preferred policies often only resolve a problem by transferring the problem to another time or location. The Appraisal offers a unique opportunity to address these and other issues.
A logic to reason about likelihood

Abstract We present a logic LL which uses a modal operator L to help capture the notion of being likely. Despite the fact that likelihood is not assigned quantitative values through probabilities, LL captures many of the properties of likelihood in an intuitively appealing way. We give a possible-worlds style semantics to LL, and, using standard techniques of modal logic, we give a complete axiomatization for LL and show that satisfiability of LL formulas can be decided in exponential time. We discuss how the logic might be used in areas such as medical diagnosis, where decision making in the face of uncertainties is crucial. We conclude by using LL to give a formal proof of correctness of some aspects of a protocol for exchanging secrets.
Do Investors Trade More When Stocks Have Performed Well? Evidence from 46 Countries

This article investigates the dynamic relation between market-wide trading activity and returns in 46 markets. Many stock markets exhibit a strong positive relation between turnover and past returns. These findings stand up in the face of various controls for volatility, alternative definitions of turnover, differing sample periods, and are present at both the weekly and daily frequency. The relation is more statistically and economically significant in countries with high levels of corruption, with short-sale restrictions, and in which market volatility is high. © The Author 2006.
Ecological and social characterization of key resource areas in Kenyan rangelands

Abstract Key resource areas (KRAs), defined as dry season foraging zones for herbivores, were studied relative to the more extensive outlying rangeland areas (non-KRAs) in Kenya. Field surveys with pastoralists, ranchers, scientists and government officials delineated KRAs on the ground. Identified KRAs were mapped based on global positioning and local experts’ information on KRAs accessibility and ecological attributes. Using the map of known KRAs and non-KRAs, we examined characteristics of soils, climate, topography, land use/cover attributes at KRAs relative to non-KRAs. How and why do some areas (KRAs) support herbivores during droughts when forage is scarce in other areas of the landscape? We hypothesized that KRAs have fundamental ecological and socially determined attributes that enable them to provide forage during critical times and we sought to characterize some of those attributes in this study. At the landscape level, KRAs took different forms based on forage availability during the dry season but generally occurred in locations of the landscape with aseasonal water availability and/or difficult to access areas during wet season forage abundance. Greenness trends for KRAs versus non-KRAs were evaluated with a 22-year dataset of Normalized Difference Vegetation Index (NDVI). Field surveys of KRAs provided qualitative information on KRAs as dry season foraging zones. At the scale of the study, soil attributes did not significantly differ for KRAs compared to non-KRAs. Slopes of KRA were generally steeper compared to non-KRAs and elevation was higher at KRAs. Field survey respondents indicated that animals and humans generally avoid difficult to access hilly areas using them only when all other easily accessible rangeland is depleted of forage during droughts. Understanding the nature of KRAs will support identification, protection and restoration of critical forage hotspots for herbivores by strengthening rangeland inventory, monitoring, policy formulation, and conservation efforts to improve habitats and human welfare.
On the Onset of Breakup in Inviscid and Viscous Jets

Abstract : This paper is concerned with the instability of inviscid and viscous jets utilizing the basic equations of the one-dimensional direct theory of a fluid jet based on the concept of a Cosserat (or a directed) curve. First, a system of differential equations is derived for small motions superposed on uniform flow of an inviscid straight circular jet which can twist along its axis. Periodic wave solutions are then obtained for this system of linear equations; and, with reference to a description of growth in the unstable mode, the comparison of the resulting dispersion relation is found to agree extremely well with the classical (three-dimensional) results of Rayleigh. Next, constitutive equations are obtained for a viscous elliptical jet and these are used to discuss both the symmetric and the anti-symmetric small disturbances in the shape of the free surface of a circular jet. Through a comparison with available three-dimensional numerical results, the solution obtained is shown to be an improvement over an existing approximate solution of the problem. (Author)
What do we really know about cosmic acceleration

Essentially all of our knowledge of the acceleration history of the universe (even the discovery of the acceleration itself) is predicated on the validity of general relativity through the Friedmann equation. Assuming only a flat spacetime that is homogenous and isotropic on large scales and described by a metric theory of gravity, we use SNe Ia to analyze the acceleration history. We infer robust conclusions about cosmic acceleration that are independent of a particular parameterization of the acceleration history. Specifically, we find (1) very strong (5 σ) evidence for a period of acceleration, (2) strong evidence that the acceleration has not been constant, (3) evidence for an earlier period of deceleration, and (4) only weak evidence that the universe has been accelerating since z ~ 0.3.
Shuffled Graph Classification: Theory and Connectome Applications

We develop a formalism to address statistical pattern recognition of graph valued data. Of particular interest is the case of all graphs having the same number of uniquely labeled vertices. When the vertex labels are latent, such graphs are called shuffled graphs. Our formalism provides insight to trivially answer a number of open statistical questions including: (i) under what conditions does shuffling the vertices degrade classification performance and (ii) do universally consistent graph classifiers exist? The answers to these questions lead to practical heuristic algorithms with state-of-the-art finite sample performance, in agreement with our theoretical asymptotics. Applying these methods to classify sex and autism in two different human connectome classification tasks yields successful classification results in both applications.
Magnon decay in gapped quantum spin systems.

In the continuum O(3) $\ensuremath{\sigma}$-model description of gapped spin systems, $S=1$ magnons can only decay into three lower energy magnons. We argue that the symmetry of the quantum spin Hamiltonian often allows decay into two magnons, and compute this decay rate in model systems. Two-magnon decay is present in Haldane gap $S=1$ spin chains, even though it cannot be induced by any allowed term written in powers and gradients of the $\ensuremath{\sigma}$-model field. We compare our results with recent measurements of Stone et al. on a two-dimensional spin system.
The kinetic properties of a human PPIP5K reveal that its kinase activities are protected against the consequences of a deteriorating cellular bioenergetic environment.

We obtained detailed kinetic characteristics–stoichiometry, reaction rates, substrate affinities and equilibrium conditions–of human PPIP5K2 (diphosphoinositol pentakisphosphate kinase 2). This enzyme synthesizes ‘high-energy’ PP-InsPs (diphosphoinositol polyphosphates) by metabolizing InsP6 (inositol hexakisphosphate) and 5-InsP7 (5-diphosphoinositol 1,2,3,4,6-pentakisphosphate) to 1-InsP7 (1-diphosphoinositol 2,3,4,5,6-pentakisphosphate) and InsP8 (1,5-bis-diphosphoinositol 2,3,4,6-tetrakisphosphate), respectively. These data increase our insight into the PPIP5K2 reaction mechanism and clarify the interface between PPIP5K catalytic activities and cellular bioenergetic status. For example, stochiometric analysis uncovered non-productive, substrate-stimulated ATPase activity (thus, approximately 2 and 1.2 ATP molecules are utilized to synthesize each molecule of 1-InsP7 and InsP8, respectively). Impaired ATPase activity of a PPIP5K2-K248A mutant increased atomic-level insight into the enzyme's reaction mechanism. We found PPIP5K2 to be fully reversible as an ATP-synthase in vitro, but our new data contradict previous perceptions that significant ‘reversibility’ occurs in vivo. PPIP5K2 was insensitive to physiological changes in either [AMP] or [ATP]/[ADP] ratios. Those data, together with adenine nucleotide kinetics (ATP Km=20–40 μM), reveal how insulated PPIP5K2 is from cellular bioenergetic challenges. Finally, the specificity constants for PPIP5K2 revise upwards by one-to-two orders of magnitude the inherent catalytic activities of this enzyme, and we show its equilibrium point favours 80–90% depletion of InsP6/5-InsP7.
Effects of Launch Vehicle Emissions in the Stratosphere

A plume dispersion and chemical kinetic model hasbeen used to estimate the total impact of motorsof different propellant types on stratospheric ozone. In previous studies, industry standard rocket motor performance and plume e owe eld computer programs were used to model the chemistry in the rocket combustion chamber and expansion nozzle and also in the downstream afterburning region of the plume. Our model and the results of previous studies were used to follow the plume chemistry for up to a day as the plume dispersed into the ambient stratosphere. Several large motor-types were analyzed: two different solid-fueled motors without chlorine and one with chlorine, an amine/N 2O4 fueled e rst stage, a kerosene/liquid oxygen (LOX) fueled e rst stage, and an l-H2/LOX fueled engine with two nozzle variants. The modeled motors are based loosely on existing vehicles, but we varied several parameters to create hypothetical vehicles that may be viewed as prototypes of next-generation launchers. Two dispersion rates were used, a worst case and a best guess, based on published models. In the worst case, ozone depletion due to NO x or other exhaust species was several orders of magnitude smaller than depletion due to chlorine in the exhaust. Depletion due to motors using LOX was minimal within 5 min of vehicle passage in all cases.
A zwitterionic viologen disulfonate-hydroquinone charge-transfer crystal: 2,2'-(4,4'-bipyridinium-1,1'-diyl)di(ethanesulfonate)-hydroquinone (1/2).

The structure of the title compound, C14H16N2O6S2·2C6H6O2, consists of 2,2′-(4,4′-bipyridinium-1,1′-diyl)di(ethanesulfon­ate) mol­ecules (with crystallographically imposed twofold symmetry) that are hydrogen bonded to each other, as well as to hydro­quinone mol­ecules, in a complex three-dimensional motif. The orange color of the crystals is indicative of the donor–acceptor interaction between the electron-rich hydro­quinone π-donor and the electron-deficient bipyridinium π-acceptor. The dihedral angle between the bipyridyl planes is 38.31 (11)°. The distance from the centroid of one of the hydro­quinone mol­ecules to the center of the bipyridinium group is 3.653 (3) A, which is within the range typically observed for molecular complexes exhibiting charge-transfer characteristics.
Optimization with extremal dynamics

A local-search heuristic for finding high-quality solutions for many hard optimization problems is explored. The method is inspired by recent progress in understanding far-from-equilibrium phenomena in terms of self-organized criticality, a concept introduced to describe emergent complexity in physical systems. This method, called extremal optimization, successively replaces the value of extremely undesirable variables in a sub-optimal solution with new, random ones. Large, avalanche-like fluctuations in the cost function emerge dynamically. These enable the search to effectively scaling barriers to explore local optima in distant neighborhoods of the configuration space while eliminating the need to tune parameters. Drawing upon models used to simulate the dynamics of granular media, evolution, or geology, extremal optimization complements approximation methods inspired by equilibrium statistical physics, such as simulated annealing. This method is very general and so far has proved competitive with--and even superior to--more elaborate general-purpose heuristics on testbeds of constrained optimization problems with up to 105 variables, such as bipartitioning, coloring, and spin glasses. Analysis of a model problem predicts the only free parameter of the method in accordance with all experimental results.
Reaction time in ankle movements: a diffusion model analysis

Reaction time (RT) is one of the most commonly used measures of neurological function and dysfunction. Despite the extensive studies on it, no study has ever examined the RT in the ankle. Twenty-two subjects were recruited to perform simple, 2- and 4-choice RT tasks by visually guiding a cursor inside a rectangular target with their ankle. RT did not change with spatial accuracy constraints imposed by different target widths in the direction of the movement. RT increased as a linear function of potential target stimuli, as would be predicted by Hick–Hyman law. Although the slopes of the regressions were similar, the intercept in dorsal–plantar (DP) direction was significantly smaller than the intercept in inversion–eversion (IE) direction. To explain this difference, we used a hierarchical Bayesian estimation of the Ratcliff’s (Psychol Rev 85:59, 1978) diffusion model parameters and divided processing time into cognitive components. The model gave a good account of RTs, their distribution and accuracy values, and hence provided a testimony that the non-decision processing time (overlap of posterior distributions between DP and IE < 0.045), the boundary separation (overlap of the posterior distributions < 0.1) and the evidence accumulation rate (overlap of the posterior distributions < 0.01) components of the RT accounted for the intercept difference between DP and IE. The model also proposed that there was no systematic change in non-decision processing time or drift rate when spatial accuracy constraints were altered. The results were in agreement with the memory drum hypothesis and could be further justified neurophysiologically by the larger innervation of the muscles controlling DP movements. This study might contribute to assessing deficits in sensorimotor control of the ankle and enlighten a possible target for correction in the framework of our on-going effort to develop robotic therapeutic interventions to the ankle of children with cerebral palsy.
Chemical‐Enzymatic Synthesis of Iminocyclitol Phosphonic Acids

Fuculose 1-phosphate and fructose-diphosphate aldolases were employed in the chemoenzymatic synthesis of the iminocyclitols 1 and 2 possessing a phosphonic acid moiety. These compounds are useful as core synthons for the development of specific glycosyltransferase inhibitors.
Teaching to transform, transforming to teach: exploring the role of teachers in human rights education in India

Background: Human rights education initiatives have proliferated in the past three decades and can be found in policy discussions, textbook reforms and grassroots initiatives across the globe. This article specifically explores the role of teachers in human rights education (HRE) by focusing on a case study of one non-governmental organisation's (NGO) programme operating across India. Purpose: This article argues that teachers' own transformation should be central to discussions of the educational reform, and presents data from an NGO-run HRE initiative in India. Additionally, while HRE teachers may be encouraged to equalise power relations within the classroom, many semi-literate communities hold teachers (and textbooks) in high regard, suggesting that their advocacy ofhuman rights may prove instrumental for HRE to go beyond the school walls, the ultimate aim of the educational project. Evidence from India contributes tothe discussion of HRE by presenting teachers' experiences with training and their use...
1180 nm linearly-polarized fiber laser with high slope efficiency employing low-loss ytterbium-doped polarization maintaining solid photonic bandgap fiber

A linearly-polarized fiber laser operating at 1180 nm was demonstrated using a low-loss ytterbium-doped polarization maintaining solid photonic bandgap fiber. A slope efficiency of 30 % was achieved.