cssi/SciSciGPT-SciSciNet huggingface dataset:
STELLAR LOCUS REGRESSION: ACCURATE COLOR CALIBRATION AND THE REAL-TIME DETERMINATION OF GALAXY CLUSTER PHOTOMETRIC REDSHIFTS

We present Stellar Locus Regression (SLR), a method of directly adjusting the instrumental broadband optical colors of stars to bring them into accord with a universal stellar color-color locus, producing accurately calibrated colors for both stars and galaxies. This is achieved without first establishing individual zeropoints for each passband, and can be performed in real-time at the telescope. We demonstrate how SLR naturally makes one wholesale correction for differences in instrumental response, for atmospheric transparency, for atmospheric extinction, and for Galactic extinction. We perform an example SLR treatment of SDSS data over a wide range of Galactic dust values and independently recover the direction and magnitude of the canonical Galactic reddening vector with 14–18 mmag RMS uncertainties. We then isolate the effect of atmospheric extinction, showing that SLR accounts for this and returns precise colors over a wide of airmass, with 5–14 mmag RMS residuals. We demonstrate that SLR-corrected colors are sufficiently accurate to allow photometric redshift estimates for galaxy clusters (using red sequence galaxies) with an uncertainty σ(z)/(1 + z) = 0.6% per cluster for redshifts 0.09 < z < 0.25. Finally, we identify our objects in the 2MASS all-sky catalog, and produce i-band zeropoints typically accurate to 18 mmag using only SLR. We offer opensource access to our IDL routines, validated and verified for the implementation of this technique, at http://stellar-locus-regression.googlecode.com. Subject headings: galaxies: fundamental parameters — methods: data analysis — stars: fundamental parameters — stars: statistics — techniques: photometric
Synthesis of macrocyclic tetrazoles for rapid photoinduced bioorthogonal 1,3-dipolar cycloaddition reactions.

A series of conformationally constrained, macrocyclic tetrazoles were expediently prepared by double alkylation of a bis(o-phenolyl)tetrazole precursor. Several of them showed excellent reactivity toward norbornene in a photoinduced tetrazole-alkene cycloaddition reaction in organic solvent as well as toward a norbornene-modified protein in PBS buffer.
Dyson-Schwinger equations: Density, temperature and continuum strong QCD

Continuum strong QCD is the application of models and continuum quantum field theory to the study of phenomena in hadronic physics, which includes; e.g., the spectrum of QCD bound states and their interactions; and the transition to, and properties of, a quark gluon plasma. We provide a contemporary perspective, couched primarily in terms of the Dyson-Schwinger equations but also making comparisons with other approaches and models. Our discourse provides a practitioners' guide to features of the Dyson-Schwinger equations [such as confinement and dynamical chiral symmetry breaking] and canvasses phenomenological applications to light meson and baryon properties in cold, sparse QCD. These provide the foundation for an extension to hot, dense QCD, which is probed via the introduction of the intensive thermodynamic variables: chemical potential and temperature. We describe order parameters whose evolution signals deconfinement and chiral symmetry restoration, and chronicle their use in demarcating the quark gluon plasma phase boundary and characterising the plasma's properties. Hadron traits change in an equilibrated plasma. We exemplify this and discuss putative signals of the effects. Finally, since plasma formation is not an equilibrium process, we discuss recent developments in kinetic theory and its application to describing the evolution from a relativistic heavy ion collision to an equilibrated quark gluon plasma.
Nearly optimal NP-hardness of vertex cover on k-uniform k-partite hypergraphs

We study the problem of computing the minimum vertex cover on kuniform k-partite hypergraphs when the k-partition is given. On bipartite graphs (k = 2), the minimum vertex cover can be computed in polynomial time. For general k, the problem was studied by Lovasz [23], who gave a k/2 -approximation based on the standard LP relaxation. Subsequent work by Aharoni, Holzman and Krivelevich [1] showed a tight integrality gap of (k/2-o(1)) for the LP relaxation. While this problem was known to be NP-hard for k ≥ 3, the first nontrivial NP-hardness of approximation factor of k/4-e was shown in a recent work by Guruswami and Saket [13]. They also showed that assuming Khot's Unique Games Conjecture yields a k/2- e inapproximability for this problem, implying the optimality of Lovasz's result. In this work, we show that this problem is NP-hard to approximate within k/2 - 1 + 1/2k - e. This hardness factor is off from the optimal by an additive constant of at most 1 for k ≥ 4. Our reduction relies on the Multi-Layered PCP of [8] and uses a gadget - based on biased Long Codes - adapted from the LP integrality gap of [1]. The nature of our reduction requires the analysis of several Long Codes with different biases, for which we prove structural properties of the so called cross-intersecting collections of set families - variants of which have been studied in extremal set theory.
The Price Impact of Joining a Currency Union: Evidence from Latvia

Does membership in a currency union matter for a country’s international relative prices? The answer to this question is critical for thinking about the implications of joining (or exiting) a common currency area. This paper is the first to use high-frequency good-level data to provide evidence that the answer is yes, at least for an important subset of consumption goods. It considers the case of Latvia, which recently dropped its pegged exchange rate and joined the euro zone. The paper analyzes the prices of thousands of differentiated goods sold by Zara, the world’s largest clothing retailer. Price dispersion between Latvia and euro zone countries collapsed swiftly following entry to the euro. The percentage of goods with nearly identical prices in Latvia and Germany increased from 6 to 89 percent. The median size of price differentials declined from 7 percent to zero. If a large number of firms also behave this way, these results suggest that membership in a currency union has significant implications for a country’s real exchange rate.
A general methodology for the asymmetric synthesis of 1-deoxyiminosugars

A general methodology for the stereoselective synthesis of 1-deoxymannojirimycin and its three other stereoisomers is described. The achiral olefin 6 was converted through the common olefin intermediate 12 to the target compounds in a highly stereocontrolled manner. The regioselective asymmetric aminohydroxylation (AA) and diastereoselective dihydroxylation reactions were used for the introduction of all four stereocenters in the targets, and the ring-closing metathesis (RCM) reaction was utilized for the construction of the required six-membered ring.
Constraints on 6D Supergravity Theories with Abelian Gauge Symmetry

We study six-dimensional N = (1,0) supergravity theories with abelian, as well as non-abelian, gauge group factors. We show that for theories with fewer than nine tensor multiplets, the number of possible combinations of gauge groups—including abelian factors—and non-abelian matter representations is finite. We also identify infinite families of theories with distinct U(1) charges that cannot be ruled out using known quantum consistency conditions, though only a finite subset of these can arise from known string constructions.
The Determinants of Success of Special Interests in Redistributive Politics

We examine what determines whether an interest group will receive favors in pork-barrel politics, using a model of majority voting with two competing parties. Each group's membership is heterogeneous in its ideological affinity for the parties. Individuals face a trade-off between party affinity and their own transfer receipts. The model is general enough to yield two often-discussed but competing theories as special cases. If the parties are equally effective in delivering transfers to any group, then the outcome of the process conforms to the "swing voter" theory: both parties woo the groups that are politically central, and most willing to switch their votes in response to economic favors. If groups have party affinities, and each party is more effective in delivering favors to its own support group, then we can get the "machine politics" outcome, where each party favors its core support group. We derive these results theoretically, and illustrate their operation in particular examples.
The synthesis of substituted phenylpyrimidines via suzuki coupling reactions

This paper describes the mon-, di-, and triarylation of the pyrimidine ring. It is possible to introduce one or more aryl rings in generally good yields and in a specific order, namely first in position 4, second in position 6, followed by position 2. A study of solvent and catalyst requirements has also been conducted.
Synthesis, structure and bonding of Gd6MTe2 (M=Co, Ni), Er6RuTe2

Abstract Three new rare earth metal-rich compounds, Gd6MTe2 (M=Co, Ni) and Er6RuTe2, were synthesized in direct reactions between the R, R3M, and R2Te3 (R=Gd, Er, M=Co, Ni, Ru). These materials all adopt the same Zr6CoAl2 structure type with space group P 6 2m (No. 189, Z=1). Single crystal structures of Gd6CoTe2 and Er6RuTe2 were determined and lattice parameters are a=b=8.3799(5), c=3.9801(4) A, and a=b=8.1473(5) A, c=3.9962(4) A, respectively. Gd6NiTe2 was characterized by X-ray powder diffraction; lattice parameters are a=b=8.412(2), c=3.9577(9) A. Metal–metal bonding correlations were analyzed using the empirical Pauling bond order concept.
Adaptive Estimation Using Multiagent Network Identifiers With Undirected and Directed Graph Topologies

In this paper, we present an adaptive estimation framework predicated on multiagent network identifiers with undirected and directed graph topologies. Specifically, the system state and plant parameters are identified online using N agents implementing adaptive observers with an interagent communication architecture. The adaptive observer architecture includes an additive term which involves a penalty on the mismatch between the state and parameter estimates. The proposed architecture is shown to guarantee state and parameter estimate consensus. Furthermore, the proposed adaptive identifier architecture provides a measure of agreement of the state and parameter estimates that is independent of the network topology, and guarantees that the deviation from the mean estimate for both the state and parameter estimates converge to zero. Finally, an illustrative numerical example is provided to demonstrate the efficacy of the proposed approach.
HYPERINVARIANT SUBSPACES FOR SOME B-CIRCULAR OPERATORS

We show that if A is a Hilbert–space operator, then the set of all projections onto hyperinvariant subspaces of A, which is contained in the von Neumann algebra υN(A) that is generated by A, is independent of the representation of υ N(A), thought of as an abstract W*–algebra. We modify a technique of Foias, Ko, Jung and Pearcy to get a method for finding nontrivial hyperinvariant subspaces of certain operators in finite von Neumann algebras. We introduce the B–circular operators as a special case of Speicher's B–Gaussian operators in free probability theory, and we prove several results about a B–circular operator z, including formulas for the B–valued Cauchy– and R–transforms of z*z. We show that a large class of L∞([0,1])–circular operators in finite von Neumann algebras have nontrivial hyperinvariant subspaces, and that another large class of them can be embedded in the free group factor L(F3). These results generalize some of what is known about the quasinilpotent DT–operator.
Measuring shapes of galaxy images — I. Ellipticity and orientation

We suggest a set of morphological measures that we believe can help in quantifying the shapes of two-dimensional cosmological images such as galaxies, clusters, and superclusters of galaxies. The method employs non-parametric morphological descriptors known as the Minkowski functionals in combination with geometric moments widely used in the image analysis. For the purpose of visualization of the morphological properties of image contour lines we introduce three auxiliary ellipses representing the vector and tensor Minkowski functionals. We study the discreteness, seeing, and noise eects on elliptic contours as well as their morphological characteristics such as the ellipticity and orientation. In order to reduce the eect of noise we employ a technique of contour smoothing. We test the method by studying simulated elliptic proles of toy spheroidal galaxies ranging in ellipticity from E0 to E7. We then apply the method to real galaxies, including eight spheroidals, three disk spirals and one peculiar galaxy, as imaged in the near-infrared Ks-band (2.2 microns) with the Two Micron All Sky Survey (2MASS). The method is numerically very ecient and can be used in the study of hundreds of thousands images obtained in modern surveys.
Bromoporphyrins as versatile synthons for modular construction of chiral porphyrins: Cobalt-catalyzed highly enantioselective and diastereoselective cyclopropanation

5,10-Bis(2‘,6‘-dibromophenyl)porphyrins bearing various substituents at the 10 and 20 positions were demonstrated to be versatile synthons for modular construction of chiral porphyrins via palladium-catalyzed amidation reactions with chiral amides. The quadruple carbon−nitrogen bond formation reactions were accomplished in high yields with different chiral amide building blocks under mild conditions, forming a family of D2-symmetric chiral porphyrins. Cobalt(II) complexes of these chiral porphyrins were prepared in high yields and shown to be active catalysts for highly enantioselective and diastereoselective cyclopropanation under a practical one-pot protocol (alkenes as limiting reagents and no slow addition of diazo reagents).
Deformation Structures in Oriented NiAl and CoAl Single Crystals Deformed at Elevated Temperature

The deformation characteristics of the B2 intermetallic alloys NiAl and CoAl have been examined using single crystals deformed at 673 K in the orientation. Slip trace analysis and transmission electron microscopy was used to characterize the deformation process. While many aspects of the deformation are similar, some distinct differences were observed. All of the alloys were found to deform by slip. NiAl was found to deform by slip on a combination of {110} and (100) slip planes with the predominant slip plane being a function of alloy stoichiometry. In contrast, CoAl was found to deform by slip only on {100} planes.
The Mortality of Hospital-Acquired Bloodstream Infections: Need for a New Vital Statistic?

Available data on both crude mortality and attributable mortality of hospital-acquired bloodstream infections suggest that such infections represent an important cause of death in the US. The use of 95% confidence limits for attributable mortality and current national vital statistics data for septicaemia corroborate the general hypothesis.
Dynamic Markov Bases

This article presents a computational approach for generating Markov bases for multiway contingency tables whose cell counts might be constrained by fixed marginals and by lower and upper bounds. Our framework includes tables with structural zeros as a particular case. Instead of computing the entire Markov bases in an initial step, our framework finds sets of local moves that connect each table in the reference set with a set of neighbor tables. We construct a Markov chain on the reference set of tables that requires only a set of local moves at each iteration. The union of these sets of local moves forms a dynamic Markov basis. We illustrate the practicality of our algorithms in the estimation of exact p-values for a three-way table with structural zeros and a sparse eight-way table. This article has online supplementary materials.
Estimating Demand Uncertainty Using Judgmental Forecasts

Measuring demand uncertainty is a key activity in supply chain planning, but it is difficult when demand history is unavailable, such as for new products. One method that can be applied in such cases uses dispersion among forecasting experts as a measure of demand uncertainty. This paper provides a test for this method and presents a heteroscedastic regression model for estimating the variance of demand using dispersion among experts' forecasts and scale. We test this methodology using three data sets: demand data at item level, sales data at firm level for retailers, and sales data at firm level for manufacturers. We show that the variance of a random variable (demand and sales for our data sets) is positively correlated with both dispersion among experts' forecasts and scale: The variance increases sublinearly with dispersion and more than linearly with scale. Further, we use longitudinal data sets with sales forecasts made three to nine months before the earnings report date for retailers and manufacturers to show that the effects of dispersion and scale on variance of forecast error are consistent over time.
Vertex theorems for capillary drops on support planes

We consider a capillary drop that contacts several planar bounding walls so as to produce singularities (vertices) in the boundary of its free surface. It is shown under various conditions that when the number of vertices is less than or equal to three, then the free surface must be a portion of a sphere. These results extend the classical theorem of H. Hopf on constant mean curvature immersions of the sphere. The conclusion of sphericity cannot be extended to more than three vertices, as we show by examples.
Propofol-based anesthesia as compared with standard anesthetic techniques for middle ear surgery

Abstract Study Objective: To determine if a total intravenous (IV) technique with propofol and fentanyl is superior to isoflurane anesthesia in patients undergoing middle ear surgery. Design: Prospective, randomized study. Setting: Inpatient Otolaryngology service at a university medical center. Patients: 102 ASA status I and II nonobese patients with no significant history of diabetes, chronic cholecystitis, neuropathy, or neuromuscular disorders that could produce delayed gastric emptying. Interventions: Patients were admitted to the study and randomly divided into three equal groups. IV administration of thiopental sodium 5 mg/kg for induction of anesthesia followed by 60% air/oxygen (O 2 ) with isoflurane 1% to 2% end-tidal for maintenance anesthesia (group 1). The same anesthetic was given as above, with the addition of droperidol 25 mcg/kg given after induction (group 2). IV administration of propofol 2 mg/kg for induction of anesthesia followed by propofol 50 to 250 mcg/kg/min for maintenance anesthesia. All groups received fentanyl 3 mcg/kg IV after induction. Measurements and Main Results: Surgical duration, induction, maintenance, and total anesthesia times were recorded in addition to eye opening and extubation. Intergroup comparisons of postoperative nausea, vomiting, and pain were done, as were recovery scores using the Steward system. Patients receiving propofol had significantly less nausea than those receiving isoflurane only (4 of 34 versus 12 of 34, p versus 8 of 34, p versus 5.1 ± 0.2 min and 5.2 ± 0.2 mm, p Conclusions: Propofol-fentanyl seems to be a better anesthetic than isoflurane-fentanyl in reducing the incidence of nausea and vomiting after middle ear surgery. Though the addition of droperidol to the isoflurane anesthetic seemed as effective, emergence from anesthesia was slower. For middle ear surgeries producing emesis, propofol-based anesthetics produced a rapid emergence with less nausea and vomiting.
Two-photon-induced chemical reactions in liquids

The two-photon absorption process was used to obtain the first observation of particle precipitation in liquids between halogen-containing organic compounds and silver-containing inorganic compounds. Photo-detachment of an electron from negative ions was found to be one important mechanism that led to these chemical reactions. Similar processes may lead to many new multiphoton-induced chemical reactions between organic and inorganic compounds.
Quasi-isometric rigidity of higher rank S -arithmetic lattices

We show that S-arithmetic lattices in semisimple Lie groups with no rank one factors are quasi-isometrically rigid.
Degradation Studies of the Non-lethal Bird Repellent, Methyl Anthranilate

Methyl anthranilate (MA), a food grade flavor and fragrance additive, has been reported to be an effective non-lethal bird repellent in a variety of situations. Despite the experimental success of MA, field studies have yielded widely differing levels of efficacy. Diminished efficacy in some field trials prob- ably results from the failure of specific formulations to retain or protect the active ingredient under natural conditions. Therefore, a clearer understanding of the physical and chemical factors affecting the stability of MA is needed. We undertook a series of laboratory studies on hydrolysis, photolysis and microbial degradation of MA, the results of which could be useful in the development of appropriate formulation strategies and residue analyses. We found the n- octanol : water partition coefficient, (P) to be 84. MA is not subject to hydrolysis at 25°C in phosphate buffer media at pH 5.0, 7.0 and 9.0. MA slowly photo- degrades under simulated UV 'sunlight'. Forty-four percent of MA is lost after 432 h illuminance at 1.25 mW cm-', which is equivalent to approximately 1200 h natural sunlight (40"N, noontime, June). Kinetic data indicate that the initial step of photolysis, subsequent to excitation, is a second-order reaction with respect to MA. A major photodegradation product appeared in an amount of about 10% of the mass balance and was determined to be an oxidized trimer of MA. MA is primarily affected by aerobic microbial degradation. For a 12 : 12 h light : dark, under laboratory illumination, 12% of water-solubilized material can be lost in the first seven days. Losses were 30% and 42% at 16 and 27 days, respectively. Under conditions of optimal bacterial growth (warmth and darkness) loss of MA was 22% at nine days and 100% by 20 days. The suscepti- bility of MA to microbial degradation is promising for the prospects of developing formulated, environmentally safe, bird repellents.
13C-13C NMR spin-spin coupling constants in saccharides: structural correlations involving all carbons in aldohexopyranosyl rings.

13C−13C Spin−spin coupling constants (JCC) have been measured in a group of aldohexopyranoses and methyl aldopyranosides singly labeled with 13C at different sites to confirm and extend prior correlations between JCC magnitude and sign and saccharide structure. Structural correlations for 2JC1,C3, 2JC2,C4, 2JC4,C6, and 2JC1,C5 have been confirmed using density functional theory calculations to test empirical predictions. These geminal couplings depend highly on the orientation of C−O bonds appended to the terminal coupled carbons, but new evidence suggests that 2JCCC values are also affected by intervening carbon structure and C−O bond rotation. 3JC1,C6 and 3JC3,C6 values show Karplus-like dependences but also are affected by in-plane terminal hydroxyl substituents. In both cases, rotation about the C5−C6 bond modulates the coupling due to the alternating in-plane and out-of-plane O6. 3JC3,C6 is also affected by C4 configuration. Both 3JC1,C6 and 3JC3,C6 are subject to remote effects involving the structu...
Two-dimensional model of laser-sustained plasmas in axisymmetric flowfields

A two-dimensional numerical model of laser-sustain ed plasmas in flowing argon has been developed. Real-gas properties and a complete radiation loss mechanism have been included, but radial velocities in the flowfield are neglected. Calculated plasma size, peak temperatures, global absorption characteristics, and thermal efficiencies are in good agreement with experiment. Radiation loss is found to be the dominant process at high laser powers, although thermal conversion efficiencies in excess of 40% (at 20 kW) can be realized by operating at high flow velocities. Nomenclature c = speed of light Cp = specific heat, J/kg - K D - focus spot diameter, mm e = electronic charge / = optical / number h = Planck constant / = laser intensity, W/m2 K = thermal conductivity, W/m-K kB = Boltzmann constant ne = electron number density, m~ 3 me - electron mass r = radius, m t =time, s T = temperature, K u,v = axial and radial velocity components, respectively, m/s z = axial position, m Zeff = radiation loss correction factor a = absorption coefficient, 1/m e = emission coefficient, W/m3 p = density, kg/m3 vc = continuum cutoff frequency, s~*
Determination of progesterone in human blood plasma.

ABSTRACT A procedure for the determination of progesterone in plasma is described. By means of a reaction with sulfuric acid-ethanol, 0.5 μg. of progesterone maybe determined. The preliminary application of this method to the estimationof progesterone in 10 ml. of pregnancy plasma and 15–20 ml. of normal plasma indicates that levels of plasma progesterone can be studied.
Origin of the Moon: Dynamical Considerations

The Moon is a unique body in the solar system. Other planets have their satellites, but only the Earth possesses a satellite whose orbital angular momentum about its primary exceeds the rotational angular momentum of the primary. For all the other planets, the orbital angular momentum of their satellites is a small fraction of the rotational momentum of the planet. While there are other satellites more massive than the Moon, no other planet possesses a satellite whose mass is such a substantial fraction of the mass of the primary. These unique dynamical characteristics of the Moon have led to a wide diversity of theories regarding its origin, and today, as in past centuries, the Moon’s origin remains a matter of debate.
Reciprocity in linear deterministic networks under linear coding

The linear deterministic model has been used recently to get a first order understanding of many wireless communication network problems [1][3][4][8]. In many of these cases, it has been pointed out that the capacity regions of the network and its reciprocal (where the communication links are reversed and the roles of the sources and the destinations are swapped) are the same. In this paper, we consider a linear deterministic communication network with multiple unicast information flows. For this model and under the restriction to the class of linear coding, we show that the rate regions for a network and its reciprocal are the same. This can be viewed as a generalization of the linear reversibility of wireline networks, already known in the network coding literature [10].
The evolution of market integration in Russia

We use a statistical model of commodity trade to measure the extent of integration between regional commodity markets within Russia. Monthly time-series data on regional commodity prices spanning 1994 through 1999 indicate substantial temporal fluctuations in integration over this period: an initial period of widespread integration gradually gave way to a period of disconnectedness in 1995 through 1997, which seems to have subsided by mid-1998. These temporal fluctuations exhibit strong statistical relationships with a host of aggregate variables; most notably, internal integration exhibits a strong negative relationship with international trade.
Worst-case Traffic for Oblivious Routing Functions

This paper presents an algorithm to find a worst-case trafficpattern for any oblivious routing algorithm on an arbitrary interconnectionnetwork topology. The linearity of channel loading offered by obliviousrouting algorithms enables the problem to be mapped to a bipartitemaximum-weight matching, which can be solved in polynomial time forrouting functions with a polynomial number of paths. Finding exact worstcaseperformance was previously intractable, and we demonstrate an examplecase where traditional characterization techniques overestimate thethroughput of a particular routing algorithm by 47%.
LP decoding meets LP decoding: A connection between channel coding and compressed sensing

This is a tale of two linear programming decoders, namely channel coding linear programming decoding (CC-LPD) and compressed sensing linear programming decoding (CS-LPD). So far, they have evolved quite independently. The aim of the present paper is to show that there is a tight connection between, on the one hand, CS-LPD based on a zero-one measurement matrix over the reals and, on the other hand, CC-LPD of the binary linear code that is obtained by viewing this measurement matrix as a binary parity-check matrix. This connection allows one to translate performance guarantees from one setup to the other.
Capacity regions and optimal power allocation for groupwise multiuser detection

In this letter, optimal power allocation and capacity regions are derived for groupwise successive interference cancellation (GSIC) systems operating in multipath fading channels, under imperfect channel estimation conditions. It is shown that the impact of channel estimation errors on the system capacity is two-fold: It affects the receiver performance within a group of users, as well as the cancellation performance (through cancellation errors). An iterative power allocation algorithm is derived, based on which it can be shown that that the total required received power is minimized when the groups are ordered according to their cancellation errors, and the first detected group has the smallest cancellation error. Performance/complexity tradeoff issues are also discussed by directly comparing the system capacity for different implementations: GSIC with linear minimum-mean-square error (LMMSE) receivers within the detection groups; GSIC with matched filter (MF) receivers; multicode LMMSE systems; and simple all MF receivers systems.
Development of a Simple Morphing Wing Using Elastomeric Composites as Skins and Actuators

Morphing wings are desired for their ability to reduce drag, to change flight characteristics, and perhaps to reduce weight by eliminating flap/aileron mechanisms. Development of two generations of a morphing wing project is documented. The work shows how a relatively low cost but realistic morphing wing test-bed can be fabricated. Wing skin, actuator, and actuator attachment development are discussed, as well as possible auxetic skin behavior. Aerodynamic characterization of the wing will be discussed in another paper. A very simple morphing wing was fabricated in generation one. The nose was able to elastically camber down approximately 25 deg and the tail 20 deg. Actuation was provided by three pneumatic "rubber muscle actuators" that produce high contractive/ tensile forces. Upper and lower wing skins were fabricated from carbon fiber/ polyurethane elastomer laminates. Lower skin buckling, actuator air leaks, and actuator attachment problems were resolved in the second generation. A finite element model of the second wing was developed and is being used to refine the morphing wing test-bed. The second wing fabrication methodology enabled smooth elastic cambering with no buckling or waviness in the skins. The nose cambered down 14 deg and the tail cambered down to 13 deg, and is capable of larger deformations. Improved leak-free biomimetic actuators and attach points now include no metal parts and have higher actuation forces due to new braided sheaths and functionally gradient matrix properties.
Pavement Network Maintenance Optimization Considering Multidimensional Condition Data

Pavement management systems inventory historical and current conditions of roadway networks, predict the future conditions of such networks, and suggest schedules for maintenance, repair, and rehabilitation activities. Such systems typically rely on a composite condition index, a one-dimensional and often discrete measure of the overall structural health and/or serviceability of pavement. The index is used during deterioration modeling, user and agency cost estimation, and selection and scheduling of maintenance activities. Pavement can suffer from a large number of related but distinct distresses. Difficulties associated with unobserved heterogeneity have hampered efforts to accurately model deterioration through composite condition indexes. At the same time, optimization techniques used to generate recommended maintenance plans have been shown both to be sensitive to deterioration model specification and to become computationally intractable as condition data increase. This research describes how a large network of related sections of pavement, each one of which may be plagued by a number of different distresses, can be managed without reducing condition data to a composite index. The use of approximate dynamic programming mitigates the curse of dimensionality that has haunted distinct Markov decision problem formulations of the maintenance optimization problem and limited their complexity. A computational study illustrates how the proposed approach leads to more sophisticated maintenance decision rules, which can be used to ensure the suggestions of pavement management systems more closely match engineering best practices. The use of multidimensional condition data can also yield more accurate deterioration models and cost estimates. The techniques introduced in this paper in the context of pavement management could easily be applied within any infrastructure management system.
TARP: Ticket-based address resolution protocol

IP networks fundamentally rely on the Address Resolution Protocol (ARP) for proper operation. Unfortunately, vulnerabilities in ARP enable a raft of Internet Protocol (IP)-based impersonation, man-in-the-middle, or Denial of Service (DoS) attacks. Proposed countermeasures to these vulnerabilities have yet to simultaneously address backward compatibility and cost requirements. This paper introduces the Ticket-based Address Resolution Protocol (TARP). TARP implements security by distributing centrally issued secure IP/Medium Access Control (MAC) address mapping attestations through existing ARP messages. We detail TARP and its implementation within the Linux operating system. We also detail the integration of TARP with the Dynamic Host Configuration Protocol (DHCP) for dynamic ticket distribution. Our experimental analysis shows that TARP improves the costs of implementing ARP security by as much as two orders of magnitude over existing protocols. We conclude by exploring a range of operational issues associated with deploying and administering ARP security.
A comparison of substance use rates among female nurses, clerical workers and blue‐collar workers

The issue of impairment of practising professional nurses by alcohol and other drugs has become a critical concern since the 1980s. The literature abounds with conjectures about the large numbers of nurses who are impaired, often without valid data to support the claims that the problem in nursing is greater than it is in the general population. This study reflects an effort to compare the reported substance use of employed female nurses with that of two other groups of working females. Survey data from 920 nurses, 405 clerical workers and 200 females employed in non-traditional trades jobs in two large eastern states in the US revealed that there was little evidence of 'abuse' of any of 15 substances; nurses did not report higher rates of substance use than the other two groups; and most reported substance use occurred in the younger age groups, reflecting the national trend. The need for continuing research efforts and confirmation of valid data, and primary prevention efforts with young female workers, including at-risk student nurses, is made evident.
Comparative Analysis of Principal Components Can be Misleading

Most existing methods for modeling trait evolution are univariate, although researchers are often interested in investigating evolutionary patterns and processes across multiple traits. Principal components analysis (PCA) is commonly used to reduce the dimensionality of multivariate data so that univariate trait models can be fit to individual principal components. The problem with using standard PCA on phylogenetically structured data has been previously pointed out yet it continues to be widely used in the literature. Here we demonstrate precisely how using standard PCA can mislead inferences: The first few principal components of traits evolved under constant-rate multivariate Brownian motion will appear to have evolved via an "early burst" process. A phylogenetic PCA (pPCA) has been proprosed to alleviate these issues. However, when the true model of trait evolution deviates from the model assumed in the calculation of the pPCA axes, we find that the use of pPCA suffers from similar artifacts as standard PCA. We show that data sets with high effective dimensionality are particularly likely to lead to erroneous inferences. Ultimately, all of the problems we report stem from the same underlying issue—by considering only the first few principal components as univariate traits, we are effectively examining a biased sample of a multivariate pattern. These results highlight the need for truly multivariate phylogenetic comparative methods. As these methods are still being developed, we discuss potential alternative strategies for using and interpreting models fit to univariate axes of multivariate data. (Brownian motion; early burst; multivariate evolution; Ornstein-Uhlenbeck; phylogenetic comparative methods; principal components analysis; quantitative genetics)
Fischer Carbene Catalysis of Alkynol Cycloisomerization: Application to the Synthesis of the Altromycin B Disaccharide

The tungsten-catalyzed cycloisomerization of alkynyl alcohols can be conducted without using photochemistry, using a stable tungsten Fischer carbene as the precatalyst for this transformation. A variety of alkynyl alcohols undergo cycloisomerization under these conditions to provide endocyclic enol ethers of five-, six-, and seven-membered ring sizes. The utility of this method is further demonstrated in the stereoselective synthesis of the disaccharide substructure of altromycin B.
Transition metal catalyzed meta-C–H functionalization of aromatic compounds

Direct functionalization of C–H bonds represents a powerful strategy for the synthesis of complex organic compounds due to its inherent efficiency. Among various approaches, transition metal catalyzed direct activation of unreactive C–H bonds is particularly effective for this purpose. However, the development of practical methods for transition metal catalyzed direct C–H functionalization has been challenging. Apart from identifying the reaction conditions that allow the activation of relatively unreactive C–H bonds, these reactions need to be selective, allowing one C–H bond to be differentiated from the rest of the ubiquitous C–H bonds of the compound. Whereas directing group guided, transition metal catalyzed ortho-C–H functionalization of aromatic compounds has seen significant growth in the past few decades, methods for meta-C–H functionalization of arenes have also emerged. This review summarizes approaches for directing group guided, transition metal catalyzed meta-C–H functionalization of aromatic compounds. Some steric-controlled, transition metal catalyzed formal meta-C–H functionalization reactions without coordinating directing groups are also discussed.
Copper‐Catalyzed α‐Amination of Phosphonates and Phosphine Oxides: A Direct Approach to α‐Amino Phosphonic Acids and Derivatives

A direct approach to important α-amino phosphonic acid derivatives has been developed by using copper-catalyzed electrophilic amination of α-phosphonate zincates with O-acyl hydroxylamines. This amination provides the first example of C–N bond formation which directly introduces acyclic and cyclic amines to the α-position of phosphonates in one step. The reaction also demonstrates high efficiency on a broad phosphonate substrate scope.
The homotopy coniveau tower

We examine the ‘homotopy coniveau tower’ for a general cohomology theory on smooth k-schemes and give a new proof that the layers of this tower for K-theory agree with motivic cohomology. In addition, we show that the homotopy coniveau tower agrees with Voevodsky's slice tower for S 1 -spectra, giving a proof of a connectedness conjecture of Voevodsky. The homotopy coniveau tower construction extends to a tower of functors on the Morel-Voevodsky stable homotopy category, and we identify this ℙ 1 -stable homotopy coniveau tower with Voevodsky's slice tower for ℙ 1 -spectra. We also show that the zeroth layer for the motivic sphere spectrum is the motivic cohomology spectrum, which gives the layers for a general ℙ 1 -spectrum the structure of a module over motivic cohomology. This recovers and extends results of Voevodsky on the zeroth layer of the slice filtration, and yields a spectral sequence that is reminiscent of the classical Atiyah-Hirzebruch spectral sequence.
Beyond crystallography: the study of disorder, nanocrystallinity and crystallographically challenged materials with pair distribution functions

Studying the structure of disordered and partially ordered materials is notoriously difficult. Recently, significant advances have been made using the atomic pair distribution function (PDF) analysis of powder diffraction data coupled with the use of advanced X-ray and neutron sources and fast computers. Here we summarize some of the more spectacular successes of this technique in studying the structure of complex materials and compounds. Our purpose is to make the PDF analysis technique familiar to the chemical community by describing its methodologies and highlighting its potential in solving structural characterization problems that are intractable by any other technique available to this community e.g. single crystal diffraction, Rietveld refinement of powder diffraction data and extended X-ray absorption fine structure analysis (EXAFS).
FAR-ULTRAVIOLET NUMBER COUNTS OF FIELD GALAXIES

The far-ultraviolet (FUV) number counts of galaxies constrain the evolution of the star formation rate density of the universe. We report the FUV number counts computed from FUV imaging of several fields including the Hubble Ultra Deep Field, the Hubble Deep Field North, and small areas within the GOODS-North and South fields. These data were obtained with the Hubble Space Telescope (HST) Solar Blind Channel of the Advance Camera for Surveys. The number counts sample an FUV AB magnitude range from 21 to 29 and cover a total area of 15.9 arcmin^2, ~4 times larger than the most recent HST FUV study. Our FUV counts intersect bright FUV Galaxy Evolution Explorer counts at 22.5 mag and they show good agreement with recent semi-analytic models based on dark matter "merger trees" by R. S. Somerville et al. We show that the number counts are ~35% lower than in previous HST studies that use smaller areas. The differences between these studies are likely the result of cosmic variance; our new data cover more lines of sight and more area than previous HST FUV studies. The integrated light from field galaxies is found to contribute between 65.9^(+8)_(–8) and 82.6^(+12)_(–)12 photons s^(–1) cm^(–2) sr^(–1) A^(–1) to the FUV extragalactic background. These measurements set a lower limit for the total FUV background light.
Nicotine is more addictive, not more cognitively therapeutic in a neurodevelopmental model of schizophrenia produced by neonatal ventral hippocampal lesions

Nicotine dependence is the leading cause of death in the United States. However, research on high rates of nicotine use in mental illness has primarily explained this co-morbidity as reflecting nicotine's therapeutic benefits, especially for cognitive symptoms, equating smoking with ‘self-medication’. We used a leading neurodevelopmental model of mental illness in rats to prospectively test the alternative possibility that nicotine dependence pervades mental illness because nicotine is simply more addictive in mentally ill brains that involve developmental hippocampal dysfunction. Neonatal ventral hippocampal lesions (NVHL) have previously been demonstrated to produce post-adolescent-onset, pharmacological, neurobiological and cognitive-deficit features of schizophrenia. Here, we show that NVHLs increase adult nicotine self-administration, potentiating acquisition-intake, total nicotine consumed and drug seeking. Behavioral sensitization to nicotine in adolescence prior to self-administration is not accentuated by NVHLs in contrast to increased nicotine self-administration and behavioral sensitization documented in adult NVHL rats, suggesting periadolescent neurodevelopmental onset of nicotine addiction vulnerability in the NVHL model. Delivering a nicotine regimen approximating the exposure used in the sensitization and self-administration experiments (i.e. as a treatment) to adult rats did not specifically reverse NVHL-induced cortical-hippocampal-dependent cognitive deficits and actually worsened cognitive efficiency after nicotine treatment stopped, generating deficits that resemble those due to NVHLs. These findings represent the first prospective evidence demonstrating a causal link between disease processes in schizophrenia and nicotine addiction. Developmental cortical-temporal limbic dysfunction in mental illness may thus amplify nicotine's reinforcing effects and addiction risk and severity, even while producing cognitive deficits that are not specifically or substantially reversible with nicotine.
Synchrotron x-ray microbeam diffraction from abalone shell

Microstructured biomaterials such as mollusk shells receive much attention at present, due to the promise that advanced materials can be designed and synthesized with biomimetic techniques that take advantage of self-assembly and aqueous, ambient processing conditions. A satisfactory understanding of this process requires characterization of the microstructure not only in the mature biomaterial, but at the growth fronts where the control over crystal morphology and orientation is enacted. In this paper, we present synchrotron microbeam x-ray diffraction (XRD) and electron microscopy observations near the nacre–prismatic interface of red abalone shell. The relative orientations of calcite and aragonite grains exhibit some differences from the idealizations reported previously. Long calcite grains impinge the nacre–prismatic boundary at 45° angles, suggestive of nucleation on (104) planes followed by growth along the c axis. In the region within 100 μm of the boundary, calcite and aragonite crystals lose their bulk orientational order, but we found no evidence for qualitative changes in long-range order such as ideal powder texture or an amorphous structure factor. XRD rocking curves determined the mosaic of calcite crystals in the prismatic region to be no broader than the 0.3° resolution limit of the beamline’s capillary optics, comparable to what can be measured on geological calcite single crystals.
Family Structure Transitions and Changes in Maternal Resources and Well-Being

This article uses data from the Fragile Families and Child Wellbeing Study to examine whether family instability is associated with changes in perceived social support, material hardship, maternal depression, and parenting stress among mothers of young children. In addition to accounting for the number of transitions that a mother experiences during the first five years of her child's life, we pay close attention to the type and timing of these transitions. We find that mothers who transition to cohabitation or marriage with their child's biological father experience declines in material hardship and that those who transition to cohabitation or marriage with another man exhibit modest declines in both material hardship and depression. Mothers who exit cohabiting or marital relationships encounter decreases in perceived social support and increases in material hardship, depression, and parenting stress. Overall, our results suggest that both the type and, to a much lesser degree, the timing of family structure transitions may influence maternal well-being.