cssi/SciSciGPT-SciSciNet huggingface dataset:
Inorganic nanoparticles engineered to attack bacteria

Antibiotics were once the golden bullet to constrain infectious bacteria. However, the rapid and continuing emergence of antibiotic resistance (AR) among infectious microbial pathogens has questioned the future utility of antibiotics. This dilemma has recently fueled the marriage of the disparate fields of nanochemistry and antibiotics. Nanoparticles and other types of nanomaterials have been extensively developed for drug delivery to eukaryotic cells. However, bacteria have very different cellular architectures than eukaryotic cells. This review addresses the chemistry of nanoparticle-based antibiotic carriers, and how their technical capabilities are now being re-engineered to attack, kill, but also non-lethally manipulate the physiologies of bacteria. This review also discusses the surface functionalization of inorganic nanoparticles with small ligand molecules, polymers, and charged moieties to achieve drug loading and controllable release.
Leading causes of TCP performance degradation over wireless links

TCP is known to have performance degradation over wireless links but causes of the performance degradation have not been well studied. In order to understand the causes and to gain insight for future enhancements, we design a series of simulations to collect performance data and use stepwise multiple regression to find the leading causes. Our analysis indicates that timeout is the dominant cause of wireless TCP performance degradation. Simulations show current enhancements fail to improve the timeout behavior and thus have limited improvement. Based on these findings, we propose a new enhancement that uses ECN to deliver congestion signals and utilizes the coherence among congestion signals to distinguish wireless losses from congestion losses. Simulation results demonstrate that this enhancement thoroughly changes TCP’s timeout behavior and improves the overall performance to a new level.
Bounded wait-free implementation of optimally resilient byzantine storage without (unproven) cryptographic assumptions

We present the first optimally resilient, bounded, wait-free implementation of a distributed atomic register, tolerating Byzantine readers and (up to one-third of) Byzantine servers, without the use of unproven cryptographic primitives or requiring communication among servers. Unlike previous (non-optimal) solutions, the sizes of messages sent to writers depend only on the actual number of active readers and not on the total number of readers in the system. With a novel use of secret sharing techniques combined with write back throttling we present the first solution to tolerate Byzantine readers information theoretically, without the use of cryptographic techniques based on unproven numbertheoretic assumptions.
Bridging DSGE models and the raw data

Abstract A method to estimate DSGE models using the raw data is proposed. The approach links the observables to the model counterparts via a flexible specification which does not require the model-based component to be located solely at business cycle frequencies, allows the non-model-based component to take various time series patterns, and permits certain types of model misspecification. Applying standard data transformations induces biases in structural estimates and distortions in the policy conclusions. The proposed approach recovers important model-based features in selected experimental designs. Two widely discussed issues are used to illustrate its practical use.
Media Influences on Body Image Dissatisfaction: the Moderating Role of Collectivism vs. Individualism

Body image is a multidimensional construct that reflects attitudes and perceptions about an individual’s physical appearance under the cultural norms and ideals rather than on actual body dimension. Previous research argues that body image problems are linked to many potentially harmful behaviors and mental illnesses, such as obsessive exercise, low self-esteem, substance abuse and eating disorders. Early study primarily focuses on analyzing and comparing body image dissatisfaction of women in particular countries. However, cross-cultural studies need to move on from simply comparing the absolute levels to investigating the relationships between several variables. It is still unclear about the influences of specific cultures, namely collectivism vs. individualism, on both thin-ideal media effect and body image dissatisfaction. There is no integrated research analyzing how various levels of acculturation and different cultures interact, thus further influencing women’s body image dissatisfaction. The underlying psychological mechanisms that resulted from acculturation are still less explored. Current study hypothesized that thin-ideal media exposure increases women’s body image dissatisfaction. Additionally, thin-ideal media and cultures were predicted to interact. Collectivist group with high acculturation differed from the collectivist group with low acculturation and fell close to the individualist group in body image dissatisfaction. Thus, researcher predicted that thin-ideal media effects on body image dissatisfaction were stronger for females in collectivist group with low acculturation than for the other two culture groups. In general, women living in the collectivistic societies would report more body image dissatisfaction than those living in the individualistic societies. This study used a 3 x 2 x 2 mixed design to examine the moderating role of collectivism vs. individualism on media influences on body image dissatisfaction among 133 female college students, aged from 18 to 23 years old, attending the University of Texas at Austin. The results indicated that thin-ideal media significantly increased women’s body image dissatisfaction, whereas healthy media decreased women’s body image dissatisfaction. In general, women living in the collectivistic society reported more body image dissatisfaction than women living in the individualistic society. Contrary to the prediction, body image dissatisfaction of women in the collectivistic group with high acculturation did not differ from those in the collectivistic group with low acculturation. Therefore, the moderating role of acculturation was not found.
Capital market financing, firm growth, and firm size distribution

How many and which firms issue equity and bonds in domestic and international markets, how do these firms grow relative to non-issuing firms, and how does firm performance vary along the firm size distribution? To evaluate these questions, a new data set is constructed by matching data on firm-level capital raising activity with balance sheet data for 45,527 listed firms in 51 countries. Three main patterns emerge from the analysis. (1) Only a few large firms issue equity or bonds, and among them a small subset has raised a large proportion of the funds raised during the 1990s and 2000s. (2) Issuers grow faster than non-issuers in assets, sales, and employment, that is, firms do not simply use securities markets to adjust their financial accounts. (3) The firm size distribution of issuers evolves differently from that of non-issuers, tightening among issuers and widening among non-issuers.
The formation of molecular hydrogen from water ice in the lunar regolith by energetic charged particles

[1] On 9 October 2009, the Lunar Crater Observation and Sensing Satellite (LCROSS) mission impacted a spent Centaur rocket into the permanently shadowed region (PSR) within Cabeus crater and detected water vapor and ice, as well as other volatiles, in the ejecta plume. The Lyman Alpha Mapping Project (LAMP), a far ultraviolet (FUV) imaging spectrograph on board the Lunar Reconnaissance Orbiter (LRO), observed this plume as FUV emissions from the fluorescence of sunlight by molecular hydrogen (H2) and other constituents. Energetic charged particles, such as galactic cosmic rays (GCRs) and solar energetic particles (SEPs), can dissociate the molecules in water ice to form H2. We examine how much H2can be formed by these types of particle radiation interacting with water ice sequestered in the regolith within PSRs, and we assess whether it can account for the H2 observed by LAMP. To estimate H2formation, we use the GCR and SEP radiation dose rates measured by the LRO Cosmic Ray Telescope for the Effects of Radiation (CRaTER). The exposure time of the ice is calculated by considering meteoritic gardening and the penetration depth of the energetic particles. We find that GCRs and SEPs could convert at least 1–7% of the original water molecules into H2. Therefore, given the amount of water detected by LCROSS, such particle radiation‒induced dissociation of water ice could likely account for a significant percentage (10–100%) of the H2measured by LAMP.
On graphic Bernstein type results in higher codimension

Let E be a minimal submanifold of R n+m that can be represented as the graph of a smooth map f: R n → R m . We apply a formula that we derived in the study of mean curvature flow to obtain conditions under which Σ must be an affine subspace. Our result covers all known ones in the general case. The conditions are stated in terms of the singular values of df.
The Blank Slate: The Modern Denial of Human Nature

The blank slate, the noble savage and the ghost in the machine: the official theory silly putty the last wall to fall culture vultures the slate's last stand. Fear and loathing: political scientists the Holy Trinity. Human nature with a human face: the fear of inequality the fear of imperfectability the fear of determinism the fear of nihilism. Know thyself: in touch with reality out of our depths the many roots of our suffering the sanctimonious animal. Hot buttons: politics violence gender children the arts. The voice of the species. Appendix: Donald E. Brown's list of human universals.
3D mouse brain reconstruction from histology using a coarse-to-fine approach

The Allen Brain Atlas project aims to bridge the divide between genomics and neuroanatomy by mapping the expression of the entire C57BL/6J mouse genome onto a high-resolution 3D anatomical reference atlas of the mouse brain. We present the image registration approach used to generate this anatomical reference from histological sections. Due to the large number of sections (525) and the presence of debris and distortions, a straightforward alignment of each slice to its neighbors fails to accurately recover the 3D shape of the brain. On the other hand, multimodality registration of histology slices to an MRI reference compromises correspondences between neighboring slices. Our approach combines the high-frequency component of slice-to-slice histology registration with the low-frequency component of the histology-to-MRI registration to produce a coarse-to-fine reconstruction that is accurate both in its global shape and in the alignment of local features.
A Short Course in Intermediate Microeconomics with Calculus

This second edition retains the positive features of being clearly written, well organized, and incorporating calculus in the text, while adding expanded coverage on game theory, experimental economics, and behavioural economics. It remains more focused and manageable than similar textbooks, and provides a concise yet comprehensive treatment of the core topics of microeconomics, including theories of the consumer and of the firm, market structure, partial and general equilibrium, and market failures caused by public goods, externalities and asymmetric information. The book includes helpful solved problems in all the substantive chapters, as well as over seventy new mathematical exercises and enhanced versions of the ones in the first edition. The authors make use of the book's full color with sharp and helpful graphs and illustrations. This mathematically rigorous textbook is meant for students at the intermediate level who have already had an introductory course in microeconomics, and a calculus course.
On the minimal revision problem of specification automata

As robots are being integrated into our daily lives, it becomes necessary to provide guarantees on their safe and provably correct operation. Such guarantees can be provided using automata theoretic task and mission planning where the requirements are expressed as temporal logic specifications. However, in real-life scenarios, it is to be expected that not all user task requirements can be realized by the robot. In such cases, the robot must provide feedback to the user on why it cannot accomplish a given task. Moreover, the robot should indicate what tasks it can accomplish which are as ?close? as possible to the initial user intent. This paper establishes that the latter problem, which is referred to as the minimal specification revision problem, is NP-complete. A heuristic algorithm is presented that can compute good approximations to the Minimal Revision Problem MRP in polynomial time. The experimental study of the algorithm demonstrates that in most problem instances the heuristic algorithm actually returns the optimal solution. Finally, some cases where the algorithm does not return the optimal solution are presented.
Financial Inclusion and Legal Discrimination Against Women : Evidence from Developing Countries

This paper documents and analyzes gender differences in the use of financial services using individual-level data from 98 developing countries. The data, drawn from the Global Financial Inclusion (Global Findex) database, highlight the existence of significant gender gaps in ownership of accounts and usage of savings and credit products. Even after controlling for a host of individual characteristics including income, education, employment status, rural residency and age, gender remains significantly related to usage of financial services. This study also finds that legal discrimination against women and gender norms may explain some of the cross-country variation in access to finance for women. The analysis finds that in countries where women face legal restrictions in their ability to work, head a household, choose where to live, and receive inheritance, women are less likely to own an account, relative to men, as well as to save and borrow. The results also confirm that manifestations of gender norms, such as the level of violence against women and the incidence of early marriage for women, contribute to explaining the variation in the use of financial services between men and women, after controlling for other individual and country characteristics.
Measuring the Middle Class in Middle-Income Countries

In the development literature, a growing middle class is often hailed as an indicator of healthy economic development and a shift away from poverty (Montgomery, M. R. 2008. The urban transformation of the developing world. Science, 319, 761–764). How safe are these middle-class citizens though from falling back into poverty? Ravallion (2010. The developing world's bulging (but vulnerable) “Middle class”. World Development, 38, 445–454. doi:10.1016/j.worlddev.2009.11.007) suggests that although the middle classes, as defined by absolute incomes, are growing in developing countries, most members are still highly vulnerable and only marginally better off than their “poor” counterparts. Is income then, the best measure of middle class, if one hopes to categorise the middle class as a group that is shielded from the harsh realities of poverty? In this predominantly descriptive analysis, I compare the size of the middle class across six countries using five distinct measures: three absolute income measures, one...
Message-passing algorithms for quadratic programming formulations of MAP estimation

Computing maximum a posteriori (MAP) estimation in graphical models is an important inference problem with many applications. We present message-passing algorithms for quadratic programming (QP) formulations of MAP estimation for pairwise Markov random fields. In particular, we use the concave-convex procedure (CCCP) to obtain a locally optimal algorithm for the non-convex QP formulation. A similar technique is used to derive a globally convergent algorithm for the convex QP relaxation of MAP. We also show that a recently developed expectation-maximization (EM) algorithm for the QP formulation of MAP can be derived from the CCCP perspective. Experiments on synthetic and real-world problems confirm that our new approach is competitive with max-product and its variations. Compared with CPLEX, we achieve more than an order-of-magnitude speedup in solving optimally the convex QP relaxation.
Compatibility of Local and Global Langlands Correspondences

We prove the compatibility of local and global Langlands correspondences for GLn, which was proved up to semisimplification in [HT]. More precisely, for the ndimensional l-adic representation Rl(Π) of the Galois group of an imaginary CM-field L attached to a conjugate self-dual regular algebraic cuspidal automorphic representation Π of GLn(AL), which is square integrable at some finite place, we show that Frobenius semisimplification of the restriction of Rl(Π) to the decomposition group of a place v of L not dividing l corresponds to Πv by the local Langlands correspondence. If Πv is square integrable for some finite place v 6 | l we deduce that Rl(Π) is irreducible. We also obtain conditional results in the case v|l.
FGF signaling acts upstream of the NOTCH and WNT signaling pathways to control segmentation clock oscillations in mouse somitogenesis

Fibroblast growth factor (FGF) signaling plays a crucial role in vertebrate segmentation. The FGF pathway establishes a posterior-to-anterior signaling gradient in the presomitic mesoderm (PSM), which controls cell maturation and is involved in the positioning of segmental boundaries. In addition, FGF signaling was shown to be rhythmically activated in the PSM in response to the segmentation clock. Here, we show that conditional deletion of the FGF receptor gene Fgfr1 abolishes FGF signaling in the mouse PSM, resulting in an arrest of the dynamic cyclic gene expression and ultimately leading to an arrest of segmentation. Pharmacological treatments disrupting FGF signaling in the PSM result in an immediate arrest of periodic WNT activation, whereas NOTCH-dependent oscillations stop only during the next oscillatory cycle. Together, these experiments provide genetic evidence for the role of FGF signaling in segmentation, and identify a signaling hierarchy controlling clock oscillations downstream of FGF signaling in the mouse.
Higgs boson production at hadron colliders

Abstract I report on a calculation of the inclusive Higgs boson production cross section at hadron colliders at next-to-next-to-leading order in QCD. The result is computed as an expansion about the threshold region. By continuing the expansion to very high order, we map the result onto basis functions and obtain the result in closed analytic form.
Highly concurrent logically synchronous multicast

We define thelogically synchronous multicast problem which imposes a natural and useful structure on message delivery order in an asynchronous system. In this problem, a computation proceeds by a sequence ofmulticasts, in which a process sends a message to some arbitrary subset of the processes, including itself. A logically synchronous multicast protocol must make it appear to every process as if each multicast occurs simultaneously at all participants of that multicast (sender plus receivers). Furthermore, if a process continually wishes to send a message, it must eventually be permitted to do so. We present a highly concurrent solution in which each multicast requires at most 4|S| messages, whereS is the set of participants in that multicast. The protocol's correctness is shown using a careful problem specification stated in the I/O automaton model. We conclude the paper by describing how the logically synchronous multicast protocol can be used for distributed simulation of algorithms expressed as I/O automata.
Synthesis of Substituted Trans-1,6-Dimethylbicyclo[4.3.0]-non-2-enes Using A Claisen Rearrangement of α-(Thioalkoxy) Esters

Abstract The Claisen rearrangement of α-(thioalkoxy)-esters provided access to substituted trans-1, 6-dimethylbicyclo[4.3.0]non-2-enes characteristic of the CD rings of the cucurbitanes.
Effective Congruences for Mock Theta Functions

Let M(q) =∑ c(n)q n be one of Ramanujan’s mock theta functions. We establish the existence of infinitely many linear congruences of the form: c(An + B) ≡ 0 (mod l j ) where A is a multiple of l and an auxiliary prime, p. Moreover, we give an effectively computable upper bound on the smallest such p for which these congruences hold. The effective nature of our results is based on the prior works of Lichtenstein [1] and Treneer [2].
Metastable vacua in warped throats at non-isolated singularities

We study the existence of metastable vacua in cascades based on fractional brane configurations at non-isolated singularities preserving \( \mathcal{N} = 1 \) supersymmetry. We find that in a large class of models the extra moduli typically generated along such cascades may be stabilized by utilizing special monopole points found recently. We illustrate this in detail for cascades based on the SPP singularity. The supergravity interpretation of these constructions in terms of warped throats with supersymmetry breaking localized near their tips as well as applications to string compactification is discussed. Our constructions are designed to realize a large class of warped throats with supersymmetry breaking localized inside of a highly curved tip region.
Variability in Carbon Availability and Eelgrass ( Zostera marina ) Biometrics Along an Estuarine Gradient in Willapa Bay, WA, USA

Because photosynthesis requires CO2, carbon limitation in aquatic environments could restrict primary production and provide signals in tissue chemistry. We took advantage of spatial variability of aqueous [CO2] in estuaries to examine within-estuary variation in biometrics of intertidal eelgrass (Zostera marina) during peak summer production. As expected from the sensitivity of carbonate equilibria to pH, aqueous [CO2] increased along an ocean-to-river gradient in Willapa Bay, WA, USA. The scale of pH variability also changed, reflecting weather-driven upwelling near the ocean, tidal advection near rivers, and reduced diel fluctuation up-estuary. Z. marina studied at eight sites in the bay integrated across these different temporal fluctuations in water chemistry to exhibit increased tissue carbon and depleted δ 13C up-estuary. However, seagrass production did not change as expected from aqueous [CO2]. Instead, small standing biomass occurred at sites with organic-rich sediments or high wave energy, investment in branching showed trends along the estuarine gradient that changed seasonally, and specific growth rates based on leaf extension did not shift with the estuarine gradient or with standing biomass. These results reinforce that estuarine seagrasses are likely to experience modified mean pH and variability due not only to ocean acidification in the strict sense (anthropogenic CO2 absorbed from the atmosphere) but also from land use, upwelling, and feedbacks from biological processes. However, responses via productivity may be less evident than in tissue chemistry.
CHARA ARRAY MEASUREMENTS OF THE ANGULAR DIAMETERS OF EXOPLANET HOST STARS

Wehavemeasuredtheangulardiametersforasampleof 24exoplanethoststarsusingGeorgiaStateUniversity’s CHARA Array interferometer. We use these improved angular diameters together with Hipparcos parallax measurements to derive linear radii and to estimate the stars’ evolutionary states. Subjectheadingginfrared:stars — planetarysystems — stars:fundamentalparameters — techniques:interferometric Online material: extended figure, machine-readable table
The Development and Application of a Beta-Gamma-Gamma Multidimensional Spectrometer

A beta-gamma-gamma multidimensional spec trometer has been developed which employs two 12-inch diameter by 8-inch thick NaI(Tl) crystals with associated 4-inch thick NaI light pipes and two 5-inch diameter by 1/2-inch thick gas proportional counters as principal detectors and which utilizes two 40-inch diameter by 24-inch thick plastic phosphors as anticoincidence shields. The detector system is coupled to two 4096 word computer memories which record gamma-ray events in coincidence with either beta detector. The gamma-ray energies identify the radionuclide while the beta detectors can identify the relative position of the radioactivity in the specimen being analyzed. The background and efficiency of the system and its application to the identification of radionuclides in environmental, biological, and extraterrestrial materials are discussed.
Structure-function studies of the interaction of the hormonally active form of vitamin D3, 1α,25-dihydroxy-vitamin D3, with the intestine

Abstract The steroid cholecalciferol or vitamin D 3 is known to undergo a successive two-step hydroxylation, first in the liver to give 25-OH-D 3 and then in the kidney to produce 1α,25-(OH) 2 -D 3 . The kidney is postulated to be the endocrine gland which produces the biologically active form of vitamin D. The biological response to 1α,25-(OH) 2 -D 3 in the target intestine is believed to occur as a consequence of association with cytoplasmic and nuclear receptors, as is the case for other classical steroid hormones. A steroid competition assay has been devised using receptors present in the intestinal chromatin. A comparison of the relative competition in the assay and biological activity of a variety of analogs has defined some of the essential structural elements required for vitamin D activity. These structure-function relationships of analogs of 1α,25-(OH) 2 -D 3 are also discussed with particular emphasis on the A-ring conformation. It is emphasized that the A-ring of these seco-steroids consist of a pair of rapidly equilibrating chair conformers. As a consequence, different chair conformations produce different orientations of substituent groups in the A-ring. It is proposed that the 1α-hydroxyl of 1α,25-dihydroxyvitamin D 3 or its geometric equivalent in analogs must occupy the equatorial as opposed to the axial orientation for optimization of biological activity.
Comparison of Photovoltaic Module Performance Measurements

Computer simulation tools used to predict the energy production of photovoltaic systems are needed in order to make informed economic decisions. These tools require input parameters that characterize module performance under various operational and environmental conditions. Depending upon the complexity of the simulation model, the required input parameters can vary from the limited information found on labels affixed to photovoltaic modules to an extensive set of parameters. The required input parameters are normally obtained indoors using a solar simulator or flash tester, or measured outdoors under natural sunlight. This paper compares measured performance parameters for three photovoltaic modules tested outdoors at the National Institute of Standards and Technology (NIST) and Sandia National Laboratories (SNL). Two of the three modules were custom fabricated using monocrystalline and silicon film cells. The third, a commercially available module, utilized triple-junction amorphous silicon cells. The resulting data allow a comparison to be made between performance parameters measured at two laboratories with differing geographical locations and apparatus. This paper describes the apparatus used to collect the experimental data, test procedures utilized, and resulting performance parameters for each of the three modules. Using a computer simulation model, the impact that differences in measured parameters have on predicted more » energy production is quantified. Data presented for each module includes power output at standard rating conditions and the influence of incident angle, air mass, and module temperature on each module's electrical performance. Measurements from the two laboratories are in excellent agreement. The power at standard rating conditions is within 1% for all three modules. Although the magnitude of the individual temperature coefficients varied as much as 17% between the two laboratories, the impact on predicted performance at various temperature levels was minimal, less than 2%. The influence of air mass on the performance of the three modules measured at the laboratories was in excellent agreement. The largest difference in measured results between the two laboratories was noted in the response of the modules to incident angles that exceed 75 deg. « less
Entropy and temperature from black-hole/near-horizon-CFT duality

We construct a two-dimensional CFT, in the form of a Liouville theory, in the near-horizon limit of four- and three-dimensional black holes. The near-horizon CFT assumes two-dimensional black hole solutions first introduced by Christensen and Fulling (1977 Phys. Rev. D 15 2088–104) and expanded to a greater class of black holes via Robinson and Wilczek (2005 Phys. Rev. Lett. 95 011303). The two-dimensional black holes admit a Diff(S1) subalgebra, which upon quantization in the horizon limit becomes Virasoro with calculable central charge. This charge and the lowest Virasoro eigen-mode reproduce the correct Bekenstein–Hawking entropy of the four- and three-dimensional black holes via the known Cardy formula (Blote et al 1986 Phys. Rev. Lett. 56 742; Cardy 1986 Nucl. Phys. B 270 186). Furthermore, the two-dimensional CFT's energy–momentum tensor is anomalous. However, in the horizon limit the energy–momentum tensor becomes holomorphic equaling the Hawking flux of the four- and three-dimensional black holes. This encoding of both entropy and temperature provides a uniformity in the calculation of black hole thermodynamic and statistical quantities for the non-local effective action approach.
An energy approach to the problem of uniqueness for the Ricci flow

We revisit the problem of uniqueness for the Ricci flow and give a short, direct proof, based on the consideration of a simple energy quantity, of Hamilton/Chen-Zhu’s theorem on the uniqueness of complete solutions of uniformly bounded curvature. With a variation of this technique we prove a further uniqueness theorem for subsolutions to a general class of mixed differential inequalities and obtain an extension of Chen-Zhu’s result to solutions (and initial data) of potentially unbounded curvature. Let M = M be a smooth manifold and g0 a Riemannian metric on M . We are interested in the question of uniqueness of solutions to the initial value problem (1) ∂ ∂t g(t) = −2 Rc(g(t)), g(0) = g0, associated to the Ricci flow on M . The broadest category in which uniqueness is currently known to hold in every dimension is that of complete solutions of uniformly bounded curvature. Theorem 1 (Hamilton [H1]; Chen-Zhu [CZ]). Suppose g0 is a complete metric and g(t) and g(t) are solutions to the initial value problem (1) satisfying sup M×[0,T ] |Rm |g(t), sup M×[0,T ] |Rm|g(t) ≤ K0. Then g(t) = g(t) for all t ∈ [0, T ]. The uniqueness of solutions to the Ricci flow is not an automatic consequence of the theory of parabolic equations, as the system (1) is only weakly-parabolic. For compact M , there are two basic arguments, both due to Hamilton. The first is a byproduct of the proof of the short-time existence of solutions in Hamilton’s orginal paper [H1] and is based on a Nash-Moser-type inverse function theorem. The second, given in [H2], effectively reduces the question of uniqueness to that for the strictly parabolic Ricci-DeTurck flow. The basis of this argument is the observation that the DeTurck diffeomorphisms, which are generally obtained as solutions to a system of ODE depending on a given solution to the Ricci-DeTurck flow, can also be represented as the solutions to a certain parabolic PDE – specifically, a harmonic map heat flow – which depends on the associated solution to the Ricci flow. As DeTurck’s method is applicable to many other geometric evolution equations with gauge-based degeneracies, this second argument of Hamilton’s gives rise to an elegant and flexible general prescription in which one exchanges the problem of uniqueness for one weakly parabolic system for the (separate) problems of existence and uniqueness for one or more auxiliary strictly parabolic systems. Date: May 2012. The author was supported in part by NSF grant DMS-0805834/DMS-1160613.
How Many Galaxies Fit in a Halo? Constraints on Galaxy Formation Efficiency from Spatial Clustering

We study galaxy clustering in the framework of halo models, where gravitational clustering is described in terms of dark matter halos. At small scales, dark matter clustering statistics are dominated by halo density profiles, whereas at large scales, correlations are the result of combining nonlinear perturbation theory with halo biasing. Galaxies are assumed to follow the dark matter profiles of the halo they inhabit, and galaxy formation efficiency is characterized by the number of galaxies that populate a halo of given mass. This approach leads to generic predictions: the galaxy power spectrum shows a power-law behavior even though the dark matter does not, and the galaxy higher order correlations show smaller amplitudes at small scales than their dark matter counterparts. Both are in qualitatively agreement with measurements in galaxy catalogs. We find that requiring the model to fit both the second- and third-order moments of the Automatic Plate Measuring Facility (APM) galaxies provides a strong constraint on galaxy formation models. The data at large scales require that galaxy formation be relatively efficient at small masses, m ≈ 1010 M☉ h-1, whereas data at smaller scales require that the number of galaxies in a halo scale approximately as the mass to the 0.8th power in the high-mass limit. These constraints are independent of those derived from the luminosity function or Tully-Fisher relation. We also predict the power spectrum, bispectrum, and higher order moments of the mass density field in this framework. Although halo models agree well with measurements of the mass power spectrum and the higher order Sp parameters in N-body simulations, the model assumption that halos are spherical leads to disagreement in the configuration dependence of the bispectrum at small scales. We stress the importance of finite-volume effects in higher order statistics and show how they can be estimated in this approach.
N-Difluoromethylation of imidazoles and benzimidazoles using the Ruppert-Prakash reagent under neutral conditions.

Direct N-difluoromethylation of imidazoles and benzimidazoles has been achieved using TMS-CF3 (the Ruppert–Prakash reagent) under neutral conditions. Difluoromethylated products were obtained in good-to-excellent yields. Inexpensive, commercially available starting materials, neutral conditions, and shorter reaction times are advantages of this methodology. Reactions are accessible through conventional as well as microwave irradiation conditions.
Evaluation of the motorcycle rider course

A sample of 516 persons who had taken the Motorcycle Safety Foundation's motorcycle rider course within the prior three years and a control group who had not taken the course completed a questionnaire about their riding exposure, violations and accidents, as a means of evaluating the effects of the course. The major findings were: (a) when controlling for age and years licensed, those who took the course did not have a lower accident rate than the control group; (b) there were no differences in the violation rates between the groups; (c) the cost of damage to the motorcycles per million miles was not less for those who took the course; and (d) the estimated cost of medical treatment of injuries per million miles was not significantly less for the group which took the course; but, (e) the mean cost of damage to the motorcycles was less for those who took the course; and (f) the mean medical cost per accident was less among those who took the course than the control group. The latter may be attributable to the finding that (g) those who took the course made more use of protective clothing, such as helmets, than the control group, and to other exposure factors affecting the severity of the accidents.
Impaired Neurotransmission in Lacrimal and Salivary Glands of a Murine Model of Sjögren’s Syndrome

A decrease in lacrimal and salivary gland secretion is a primary cause of dry eye and dry mouth. Sjogren’s syndrome is the leading cause of the aqueous tear-deficient type of dry eye. 1-3 It is an autoimmune disease occurring almost exclusively in females (> 90%) and involves an extensive lymphocytic infiltration of the lacrimal and salivary glands as well as destruction of epithelial cells. 1-3 No cure exists for this disease. Moreover, its exact etiology is largely unknown, but may involve numerous factors including those of viral, endocrine, neural, genetic and environmental origin. 2-4-5
Integral cohomology of certain Picard modular surfaces

Let be the Picard modular group of an imaginary quadratic number field k and let D be the associated symmetric space. Let be a congruence subgroup. We describe a method to compute the integral cohomology of the locally symmetric space G\D. The method is implemented for the cases k=Q(i) and , and the cohomology is computed for various G. [The original abstract for this article contains characters that cannot be displayed here. Please click on the link below to read the full abstract and article.]
The Meinunger "Nicht Rote" Objects

Four high-latitude slow variable stars have been noted by Meinunger (1972) as “nicht rote” (“not red”) objects and thus curious. We have previously reported (Margon & Deutsch 1997) that one of these objects, CC Boo, is in fact a QSO. Here we present observations demonstrating that the remaining three are also highly variable active galactic nuclei. The most interesting object of the four is perhaps S 10765 (= NGP9 F324-0276706), which proves to be a resolved galaxy at z = 0.063. Despite the rapid and large reported variability amplitude (�m � 1.6 mag), the spectrum is that of a perfectly normal galaxy, with no emission lines or evident nonthermal continuum. We also present new spectroscopic and photometric observations for AR CVn, suggested by Meinunger to be an RR Lyrae star despite its very faint magnitude (=19.4). The object is indeed one of the most distant RR Lyrae stars known, at a galactocentric distance of � 40 kpc.
Local seismic attributes

Local seismic attributes measure seismic signal characteristics not instantaneously, at each signal point, and not globally, across a data window, but locally in the neighborhood of each point. I define local attributes with the help of regularized inversion and demonstrate their usefulness for measuring local frequencies of seismic signals and local similarity between different data sets. I use shaping regularization for controlling the locality and smoothness of local attributes. A multicomponent-image-registration example from a nine-component land survey illustrates practical applications of local attributes for measuring differences between registered images.
HIGH ENERGY NEUTRON FLUX DETECTION WITH DIELECTRIC PLASTICS.

Abstract Dielectric plastics were irradiated with high energy neutrons to investigate their usefulness as flux detectors. Shields thick to heavy particles and of varying composition were placed in front of the plastics to test their effectiveness as radiators. Track producing particles resulted from (n, 4He) reactions and from recoils of light nuclei. Elements possessing high (n, 4He) cross sections were chosen as shields along with other heavy elements chosen to screen the surface of the plastic from all external track-producing particles. Carbon and aluminum satisfied the first condition while gold and lead satisfied the second. After etching, the track densities in cellulose nitrate were counted. The sensitivity under graphite varied from about 2.7 × 10−5 to 3.4 × 10−5 tracks/neutron for neutrons between 13.1 and 17.1 MeV. Useful track densities are produced by fluxes in the range of about 2 × 108 to 5 × 1010 n 0/cm2. The 12C (n, n'3 4He) reaction also took place in the carbon nuclei within the plastic...
Is solid-state the future of lighting?

The rapid pace of solid state technological development over the past four decades has resulted in almost universal acceptance of the phrase "Moore's Law," whether it is used accurately to refer to the exponential increase in computer processor power or to refer to some more amorphous scope of rapid change. More recent breakthroughs in LED science and engineering have precipitated a vigorous discussion of the depth and pace with which solid state light sources will penetrate the $50-billion world-wide lighting market. This discussion has not two perspectives but many, and each perspective can provide valuable insight into key issues that will determine the role that solid state technology will play in the lighting market of 2020 and beyond.
Perfect equilibrium and intergenerational conflict in a model of cooperative enterprise growth

Abstract This paper employs an overlapping-generations model to examine the hiring and investment decisions of a cooperative enterprise whose members do not possess full ownership rights to capital. The need to internally finance investment generates a conflict of interest between junior and senior workers; the latter will be reluctant to forego salaries to self-finance investment if the returns are not fully realized before retirement. The resolution of this conflict determines the rate of growth of the firm. Solutions are first presented for two extreme scenarios: complete decision-making power to the old and complete decision-making power to the young. These solutions are then compared with the results of a majority-voting rule.
Microstructural Observations on Hot-Pressed Si3N4

The development of microstructure in hot-pressed SiaN4 was studiehd for a typical Si3N4 powder with and without BeSiN2 as a densification aid. The effect of hot-pressing temperature on density, α- to β-Si3N4 conversion and specific surface area showed that BeSiN2 appears to increase the mobility of the system by enhancing densification, α- to β-Si3N4 transformation, and grain growth at temperatures between 1450° and 1800°. These processes appear to occur in the presence of a liquid phase.
OSIRIDE: state of the art and future developments

Abstract OSIRIDE (OSI over Heterogeneous Italian Data Network) is the result of the efforts of a number of persons mainly from the Italian National Research Council and industries. The first phase of OSIRIDE (named OSIRIDE/I), dealing with the formal specifications production of a number of protocols, was completed on schedule and in accordance with the initial objectives. The second phase of the project (named OSIRIDE/II), dealing with implementation, started at the beginning of the 1984. Previous papers have already introduced OSIRIDE, its goals, participants and technical choices. However, for the sake of understandability, a brief resume of the whole project is dealt with in the first sections: for more information the interested reader is referred to the papers cited.
Holomorphic Isometry from a Kähler Manifold into a Product of Complex Projective Manifolds

We study the global property of local holomorphic isometric mappings from a class of Kahler manifolds into a product of projective algebraic manifolds with induced Fubini-Study metrics, where isometric factors are allowed to be negative.
Low-cost SWIR sensors: advancing the performance of ROIC-integrated colloidal quantum dot photodiode arrays

RTI has developed a novel photodiode technology based on solution-processed PbS colloidal quantum dots (CQD) capable of providing low-cost, high performance detection across the Vis-SWIR spectral range. The most significant advantages of the CQD technology are ease of fabrication, small pixel size, and extended wavelength range. The devices are fabricated directly onto the ROIC substrate at low temperatures compatible with CMOS, and arrays can be fabricated at wafer scale. We will discuss recent advances in device architecture and processing that result in measured dark currents of 15 nA/cm 2 at room temperature and enhanced SWIR responsivity from the UV to ~1.7 μm, compare these results to InGaAs detectors, and present measurements of the CQD detectors temperature dependent dark current.
The hot spots problem in planar domains with one hole

There exists a planar domain with piecewise smooth boundary and one hole such that the second eigenfunction for the Laplacian with Neumann boundary conditions attains its maximum and minimum inside the domain.
Viscoelastic Properties of Soft Tissue by Discrete Model Characterization

Abstract In order to study the response of the human body to acceleration and force, it is necessary to be able to relate force to deformation in various body tissues. Problems in which this becomes essential include aerospace travel, crash injury research, and shock/vibration environments produced by mechanical systems. Since the tissues within the human body are viscoelastic in nature, it is important to apply proper viscoelastic relations when investigating the mechanics of deformation. An experimental technique for ootaining discrete viscoelastic models of soft biological tissues and the application of this technique (using guinea pig skin as an example) are described. Numerical results for the various viscoelastic parameters are presented, and discrete viscoelastic modeling and the necessary mathematical equations for relating deformation to force are discussed.
THERMAL STRESS AND VOLUME CHANGE DURING A COOLING PROCESS INVOLVING PHASE TRANSFORMATION

With the aid of a phase diagram, a theoretical principle is developed to calculate the stress in the matrix phase and the overall volume change of dual-phase metals during a cooling process involving martensitic transformation. The cooling process may start from a pure austenite phase or from a mixture of austenite and ferrite, resulting in a two- or a three-phase system during the phase transformation. The transformed martensites in the former case are taken to be randomly oriented spheroids. In the latter case, ferrite is taken as the matrix, whereas austenite will transform into martensite, both existing as randomly oriented spheroidal inclusions. The theory is developed using Eshelby's inhomogeneity and transformation principle, by which the influence of elastic heterogeneity, thermal expansion coefficients, phase-transformation strain, and inclusion shape can all be accounted for. When applied to the iron—carbon system, it is found that, for a typical cooling path, the thermal stress developed in the...
Cosmic defects and CMB anisotropy

Recent measurements of the cosmic microwave background (CMB) anisotropies by BOOMERANG and MAXIMA collaborations have tightened the observational constraints on theories of structure formation. They disagree with the predictions of conventional topological defect models. Considering the fact that topological defects are predicted by the majority of realistic particle physics models, the exact nature of the constraints imposed by the recent data on the population and the properties of the defects must be fully understood. We show that the predictions of current cosmic string models can be brought into a closer agreement with the observations by choosing a closed universe with Ω = 1.3 and by including the effects of the small-scale structure and radiation products of the strings. These alone, however, are not sufficient for obtaining a good fit to the measured shape of the angular power spectrum. To fit the data cosmic strings would either have to be correlated on large (perhaps superhorizon) scales or would have to possess a higher degree of coherence, i.e. be more "time-correlated".