cssi/SciSciGPT-SciSciNet huggingface dataset:
The impacts of safety nets in Africa : what are we learning ?

Safety nets in Africa are a popular policy instrument to address the widespread chronic poverty and encourage human capital investments in the education and health of children. Although there have been considerable analyses on the impacts of safety nets globally, particularly in Latin America, less been done on synthesizing results across Sub-Saharan African programs. This study fills this gap by systematically extracting and standardizing the results across impact evaluations for better understanding of what has been achieved using this policy instrument in the continent. The study finds that these programs on average have significant positive impacts on total and food consumption. The programs show promising results on asset accumulation, such as livestock ownership. However, there is substantial heterogeneity in the impacts achieved across programs for some development outcomes. Through exploring this heterogeneity in impacts, the study puts forward several suggestions for better targeting various development outcomes through modifications in the design and implementation of safety net programs.
Conversion efficiency of α-linolenic acid to omega-3 highly unsaturated fatty acids in aerial insectivore chicks

Food availability and quality are both critical for growing young animals. In nature, swallows (Tachycineta bicolor) and other aerial insectivores feed on both aquatic insects, which are rich in omega-3 highly unsaturated fatty acids (HUFAs), and terrestrial insects, which contain considerably lower amounts of omega-3 HUFAs. Carnivorous mammals and fishes must obtain omega-3 HUFAs from their diet, as they have lost the capacity to convert the precursor omega-3 α-linolenic acid (ALA) into omega-3 HUFAs. Thus, the relative value of aquatic versus terrestrial insects depends not only on the fatty acid composition of the prey but also on the capacity of consumers to convert ALA into omega-3 HUFAs. We used a combination of stable-isotope-labeled fatty acid tracers to ask whether, and how efficiently, tree swallows can deposit newly synthesized omega-3 HUFAs into tissue. Our data show for the first time that tree swallows can convert ALA into omega-3 HUFAs deposited in liver and skeletal muscle. However, high tree swallow demand for omega-3 HUFAs combined with low ALA availability in natural terrestrial foods may strain their modest conversion ability. This suggests that while tree swallows can synthesize omega-3 HUFAs de novo, omega-3 HUFAs are ecologically essential nutrients in natural systems. Our findings thus provide mechanistic support for our previous findings and the importance of omega-3 HUFA-rich aquatic insects for tree swallows and most likely other aerial insectivores with similar niches.
BIOMECHANICAL COMPARISON OF TWO AUGMENTED GLENOID DESIGNS: A FINITE ELEMENT ANALYSIS

Introduction Varying degrees of posterior glenoid bone loss occurs in patients with end stage osteoarthritis and can result in increased glenoid retroversion. Ultimately, the goal is to correct retroversion to restore normal biomechanics of the glenohumeral joint. The goal of this study was to identify the optimal augmented glenoid design based on finite element model analysis which will provide key insights into implant loosening mechanisms and stability. Materials and Methods Two different augmented glenoid designs, posterior wedge and posterior step- were created as a computer model by a computer aided design software (CAD). These implants were virtually implanted to correct 20° glenoid retroversion and the different mechanical parameters were calculated including: the glenohumeral contact pressure, the cement stress, the shear stress, and relative micromotions at the bone cement interface. Results During abduction, high strain was concentrated around the peg and posterior glenoid bone. Strain was noticeably higher in stepped design (1–2%) than the wedged design (0.4–1.2%). Stepped glenoid models sustained 30% and 70% higher stresses than those experienced by the wedged glenoid implant models at two different corrections. Distractions predicted by the stepped designs were found to be at least twice as much as those by the wedged designs. Similarly, in compression values were 1.5–8 magnitudes higher in stepped designs than those of wedged designs. The wedged design, the amount of micromotion was not affected by the size of the augment (8° and 16°). Discussion Our study showed that the wedged design experienced less stress compared to stepped design with abduction loading. Notably, the wedged design experienced less stress as the size of the wedge increased to correct a more retroverted arthritic glenoid. The step design also had the highest amount of micromotion which ultimately points to increased failures rate and decreased performace.
Do fire sales create externalities

Abstract We develop three novel measures of the incentives of equity mutual funds to internalize the price impact of their trading. We show that mutual funds with stronger incentives to internalize their price impact accommodate inflows and outflows by adjusting their cash buffers instead of trading in portfolio securities. As a result, stocks held by these funds have lower volatility, and flows out of these funds have smaller spillover effects on other funds holding the same securities. Our results provide evidence of meaningful fire sale externalities in the equity mutual fund industry.
From Decentralized to Centralized Irrigation Management

Abstract Centralized organizations can internalize transaction costs and externalities, addressing possible inefficiencies of decentralized management. In practice, however, centralized organizations can have its own inefficiencies and decentralized management can do relatively well. Empirically testing relative efficiency is difficult because distinct organizations emerge endogenously in various contexts. This paper, in contrast, draws upon the unique history of New Mexico, leveraging a natural experiment to assess how the partial transition in the early 20th century from the original small decentralized communal Spanish irrigation systems (acequias) to centralized quasi-public irrigation districts altered agricultural development and production. Surface water irrigators in arid regions confront public good issues for building and maintaining shared infrastructure as well as common-pool resource issues to appropriate the surface water. My results confirm that irrigation districts can significantly improve outcomes when investing in costly infrastructure to expand irrigated acreage, increasing farmland values up to 33%. However, I find no broader evidence that the centralized control of water distribution provides any gains to acreage previously under irrigation by the decentralized acequias.
Superresolution without separation

This paper provides a theoretical analysis of diffraction-limited superresolution, demonstrating that arbitrarily close point sources can be resolved in ideal situations. Precisely, we assume that the incoming signal is a linear combination of M shifted copies of a known waveform with unknown shifts and amplitudes, and one only observes a finite collection of evaluations of this signal. We characterize properties of the base waveform such that the exact translations and amplitudes can be recovered from 2M + 1 observations. This recovery is achieved by solving a a weighted version of basis pursuit over a continuous dictionary. Our methods combine classical polynomial interpolation techniques with contemporary tools from compressed sensing.
Predicting CTCF-mediated chromatin loops using CTCF-MP.

Motivation The three dimensional organization of chromosomes within the cell nucleus is highly regulated. It is known that CCCTC-binding factor (CTCF) is an important architectural protein to mediate long-range chromatin loops. Recent studies have shown that the majority of CTCF binding motif pairs at chromatin loop anchor regions are in convergent orientation. However, it remains unknown whether the genomic context at the sequence level can determine if a convergent CTCF motif pair is able to form a chromatin loop. Results In this article, we directly ask whether and what sequence-based features (other than the motif itself) may be important to establish CTCF-mediated chromatin loops. We found that motif conservation measured by 'branch-of-origin' that accounts for motif turn-over in evolution is an important feature. We developed a new machine learning algorithm called CTCF-MP based on word2vec to demonstrate that sequence-based features alone have the capability to predict if a pair of convergent CTCF motifs would form a loop. Together with functional genomic signals from CTCF ChIP-seq and DNase-seq, CTCF-MP is able to make highly accurate predictions on whether a convergent CTCF motif pair would form a loop in a single cell type and also across different cell types. Our work represents an important step further to understand the sequence determinants that may guide the formation of complex chromatin architectures. Availability and implementation The source code of CTCF-MP can be accessed at: https://github.com/ma-compbio/CTCF-MP. Supplementary information Supplementary data are available at Bioinformatics online.
The Physics of Energy

The Physics of Energy provides a comprehensive and systematic introduction to the scientific principles governing energy sources, uses, and systems. This definitive textbook traces the flow of energy from sources such as solar power, nuclear power, wind power, water power, and fossil fuels through its transformation in devices such as heat engines and electrical generators, to its uses including transportation, heating, cooling, and other applications. The flow of energy through the Earth's atmosphere and oceans, and systems issues including storage, electric grids, and efficiency and conservation are presented in a scientific context along with topics such as radiation from nuclear power and climate change from the use of fossil fuels. Students, scientists, engineers, energy industry professionals, and concerned citizens with some mathematical and scientific background who wish to understand energy systems and issues quantitatively will find this textbook of great interest.
Giant perpendicular magnetic anisotropy in Fe/III-V nitride thin films

Large perpendicular magnetic anisotropy (PMA) in transition metal thin films provides a pathway for enabling the intriguing physics of nanomagnetism and developing broad spintronics applications. After decades of searches for promising materials, the energy scale of PMA of transition metal thin films, unfortunately, remains only about 1 meV. This limitation has become a major bottleneck in the development of ultradense storage and memory devices. We discovered unprecedented PMA in Fe thin-film growth on the [Formula: see text] N-terminated surface of III-V nitrides from first-principles calculations. PMA ranges from 24.1 meV/u.c. in Fe/BN to 53.7 meV/u.c. in Fe/InN. Symmetry-protected degeneracy between x2 - y2 and xy orbitals and its lift by the spin-orbit coupling play a dominant role. As a consequence, PMA in Fe/III-V nitride thin films is dominated by first-order perturbation of the spin-orbit coupling, instead of second-order in conventional transition metal/oxide thin films. This game-changing scenario would also open a new field of magnetism on transition metal/nitride interfaces.
Cicero and the new poetry

and for his criticism of the New Poets, of which too much perhaps has been made. Cicero's criticism consists of three brief comments, personal and incidental, the earliest in a letter to Atticus (late November 50 B.C.). The crossing to Brundisium was speedy and pleasant, he writes, with a fair wind: flauit ab Epiro lenissimus Onchesmites-an elegant spondaic hexameter in the new style, Cicero's witty improvisation, as it must be, which he invites Atticus to sell as if it were his own to any New Poet he pleases.2 It is clear that Cicero was out of sympathy with these modish young poets; he was amused, the older man of letters, and
Complete characterization of a class of privacy-preserving tracking problems:

We examine the problem of target tracking whilst simultaneously preserving the target’s privacy as epitomized by the robotic panda-tracking scenario, which O’Kane introduced at the 2008 Workshop on...
Power Factor Improvement of a Transverse Flux Machine With High Torque Density

Design of a transverse flux machine (TFM) with high power factor and high torque density is presented. Detailed analysis and verification of the benefit of TFMs over conventional radial flux machines, in terms of torque production capability, is described. A comprehensive investigation of the ideal torque production capability, power factor, and deviation from ideal cases is explained. Factors contributing to performance degradation are identified and a robust method is proposed to design and improve the machine performance. Simulation and experimental results are provided to validate the innovation and the robustness of the design process.
Physical interactions reduce the power of natural selection in growing yeast colonies

Microbial populations often assemble in dense populations in which proliferating individuals exert mechanical forces on the nearby cells. Here, we use yeast strains whose doubling times depend differently on temperature to show that physical interactions among cells affect the competition between different genotypes in growing yeast colonies. Our experiments demonstrate that these physical interactions have two related effects: they cause the prolonged survival of slower-growing strains at the actively-growing frontier of the colony and cause faster-growing strains to increase their frequency more slowly than expected in the absence of physical interactions. These effects also promote the survival of slower-growing strains and the maintenance of genetic diversity in colonies grown in time-varying environments. A continuum model inspired by overdamped hydrodynamics reproduces the experiments and predicts that the strength of natural selection depends on the width of the actively growing layer at the colony frontier. We verify these predictions experimentally. The reduced power of natural selection observed here may favor the maintenance of drug-resistant cells in microbial populations and could explain the apparent neutrality of interclone competition within tumors.
5G-CORNET: Platform as a Service

Practical testing of the latest wireless communications standards requires the availability of flexible radio frequency hardware, networking and computing resources. We are providing a Cloud-based infrastructure which offers the necessary resources to carry out tests of the latest 5G standards. The testbed provides a Cloud-based Infrastructure as a Service. The research community can access hardware and software resources through a virtual platform that enables isolation and customization of experiments. In other words, researchers have control over the preferred experimental architecture and can run concurrent experiments on the same testbed. This paper introduces the resources that can be used to develop 5G testbeds and experiments.
On the separability of stochastic geometric objects, with applications

Abstract In this paper, we study the linear separability problem for stochastic geometric objects under the well-known unipoint and multipoint uncertainty models. Let S = S R ∪ S B be a given set of stochastic bichromatic points, and define n = min ⁡ { | S R | , | S B | } and N = max ⁡ { | S R | , | S B | } . We show that the separable-probability (SP) of S can be computed in O ( n N d − 1 ) time for d ≥ 3 and O ( min ⁡ { n N log ⁡ N , N 2 } ) time for d = 2 , while the expected separation-margin (ESM) of S can be computed in O ( n N d ) time for d ≥ 2 . In addition, we give an Ω ( n N d − 1 ) witness-based lower bound for computing SP, which implies the optimality of our algorithm among all those in this category. Also, a hardness result for computing ESM is given to show the difficulty of further improving our algorithm. As an extension, we generalize the same problems from points to general geometric objects, i.e., polytopes and/or balls, and extend our algorithms to solve the generalized SP and ESM problems in O ( n N d ) and O ( n N d + 1 ) time, respectively. Finally, we present some applications of our algorithms to stochastic convex hull-related problems.
ActiveStereoNet: End-to-End Self-Supervised Learning for Active Stereo Systems

In this paper we present ActiveStereoNet, the first deep learning solution for active stereo systems. Due to the lack of ground truth, our method is fully self-supervised, yet it produces precise depth with a subpixel precision of 1 / 30th of a pixel; it does not suffer from the common over-smoothing issues; it preserves the edges; and it explicitly handles occlusions. We introduce a novel reconstruction loss that is more robust to noise and texture-less patches, and is invariant to illumination changes. The proposed loss is optimized using a window-based cost aggregation with an adaptive support weight scheme. This cost aggregation is edge-preserving and smooths the loss function, which is key to allow the network to reach compelling results. Finally we show how the task of predicting invalid regions, such as occlusions, can be trained end-to-end without ground-truth. This component is crucial to reduce blur and particularly improves predictions along depth discontinuities. Extensive quantitatively and qualitatively evaluations on real and synthetic data demonstrate state of the art results in many challenging scenes.
Urban Spatial Order: Street Network Orientation, Configuration, and Entropy

Street networks may be planned according to clear organizing principles or they may evolve organically through accretion, but their configurations and orientations help define a city’s spatial logic and order. Measures of entropy reveal a city’s streets’ order and disorder. Past studies have explored individual cases of orientation and entropy, but little is known about broader patterns and trends worldwide. This study examines street network orientation, configuration, and entropy in 100 cities around the world using OpenStreetMap data and OSMnx. It measures the entropy of street bearings in weighted and unweighted network models, along with each city’s typical street segment length, average circuity, average node degree, and the network’s proportions of four-way intersections and dead-ends. It also develops a new indicator of orientation-order that quantifies how a city’s street network follows the geometric ordering logic of a single grid. A cluster analysis is performed to explore similarities and differences among these study sites in multiple dimensions. Significant statistical relationships exist between city orientation-order and other indicators of spatial order, including street circuity and measures of connectedness. On average, US/Canadian study sites are far more grid-like than those elsewhere, exhibiting less entropy and circuity. These indicators, taken in concert, help reveal the extent and nuance of the grid. These methods demonstrate automatic, scalable, reproducible tools to empirically measure and visualize city spatial order, illustrating complex urban transportation system patterns and configurations around the world.
Joint Chance Constraints in AC Optimal Power Flow: Improving Bounds Through Learning

This paper considers distribution systems with a high penetration of distributed, renewable generation and addresses the problem of incorporating the associated uncertainty into the optimal operation of these networks. Joint chance constraints, which satisfy multiple constraints simultaneously with a prescribed probability, are one way to incorporate uncertainty across sets of constraints, leading to a chance-constrained optimal power flow problem. Departing from the computationally heavy scenario-based approaches or approximations that transform the joint constraint into conservative deterministic constraints; this paper develops a scalable, data-driven approach which learns operational trends in a power network, eliminates zero-probability events (e.g., inactive constraints), and accurately and efficiently approximates bounds on the joint chance constraint iteratively. In particular, the proposed framework improves upon the classic methods based on the union bound (or Boole’s inequality) by generating a much less conservative set of single chance constraints that also guarantees the satisfaction of the original joint constraint. The proposed framework is evaluated numerically using the IEEE 37-node test feeder, focusing on the problem of voltage regulation in distribution grids.
Bridging the spatiotemporal scales of macromolecular transport in crowded biomimetic systems

Crowding plays a key role in the transport and conformations of biological macromolecules. Gene therapy, viral infection, and transfection require DNA to traverse the crowded cytoplasm, including the cytoskeletal network of filamentous proteins. Given the complexity of cellular crowding, the dynamics of biological molecules can be highly dependent on the spatiotemporal scale probed. We present a powerful platform that spans molecular and cellular scales by coupling single-molecule conformational tracking (SMCT) and selective-plane illumination differential dynamic microscopy (SPIDDM). We elucidate the transport and conformational properties of large DNA, crowded by custom-designed networks of actin and microtubules, to link single-molecule conformations with ensemble DNA transport and cytoskeleton structure. We show that actin crowding leads to DNA compaction and suppression of fluctuations, combined with subdiffusion and heterogeneous transport, whereas microtubules have much more subdued impact across all scales. In composite networks of both filaments, scale-dependent effects emerge such that actin dictates ensemble DNA transport while microtubules influence single-molecule dynamics. We show that these intriguing results arise from a complex interplay between network rigidity, mesh size, filament concentration, and DNA size.
Beyond backprop: Online alternating minimization with auxiliary variables

Despite significant recent advances in deep neural networks, training them remains a challenge due to the highly non-convex nature of the objective function. State-of-the-art methods rely on error backpropagation, which suffers from several well-known issues, such as vanishing and exploding gradients, inability to handle non-differentiable nonlinearities and to parallelize weight-updates across layers, and biological implausibility. These limitations continue to motivate exploration of alternative training algorithms, including several recently proposed auxiliary-variable methods which break the complex nested objective function into local subproblems. However, those techniques are mainly offline (batch), which limits their applicability to extremely large datasets, as well as to online, continual or reinforcement learning. The main contribution of our work is a novel online (stochastic/mini-batch) alternating minimization (AM) approach for training deep neural networks, together with the first theoretical convergence guarantees for AM in stochastic settings and promising empirical results on a variety of architectures and datasets.
Crowd-AI Systems for Non-Visual Information Access in the Real World

The world is full of information, interfaces and environments that are inaccessible to blind people. When navigating indoors, blind people are often unaware of key visual information, such as posters, signs, and exit doors. When accessing specific interfaces, blind people cannot independently do so without at least first learning their layout and labeling them with sighted assistance. My work investigates interactive systems that integrates computer vision, on-demand crowdsourcing, and wearables to amplify the abilities of blind people, offering solutions for real-time environment and interface navigation. My work provides more options for blind people to access information and increases their freedom in navigating the world.
The nonlinear effects of uncertainty shocks

We consider the effects of uncertainty shocks in a nonlinear VAR that allows uncertainty to have amplification effects. When uncertainty is relatively low, fluctuations in uncertainty have small, linear effects. In periods of high uncertainty, the effect of a further increase in uncertainty is magnified. We find that uncertainty shocks in this environment have a more pronounced effect on real economic variables. We also conduct counterfactual experiments to determine the channels through which uncertainty acts. Uncertainty propagates through both the household consumption channel and through businesses delaying investment, providing substantial contributions to the decline in GDP observed after uncertainty shocks. Finally, we find evidence of the ability of systematic monetary policy to mitigate the adverse effects of uncertainty shocks.
Mechanical Properties of Graphene Nanoplatelet Carbon Fiber Epoxy Hybrid Composites: Multiscale Modeling and Experiments

Because of the relatively high specific mechanical properties of carbon fiber/epoxy composite materials, they are often used as structural components in aerospace applications. Graphene nanoplatelets (GNPs) can be added to the epoxy matrix to improve the overall mechanical properties of the composite. The resulting GNP/carbon fiber/epoxy hybrid composites have been studied using multiscale modeling to determine the influence of GNP volume fraction, epoxy crosslink density, and GNP dispersion on the mechanical performance. The hierarchical multiscale modeling approach developed herein includes Molecular Dynamics (MD) and micromechanical modeling, and it is validated with experimental testing of the same hybrid composite material system. The results indicate that the multiscale modeling approach is accurate and provides physical insight into the composite mechanical behavior. Also, the results quantify the substantial impact of GNP volume fraction and dispersion on the transverse mechanical properties of the hybrid composite, while the effect on the axial properties is shown to be insignificant.
An n→π* Interaction in the Bound Substrate of Aspartic Proteases Replicates the Oxyanion Hole.

Aspartic proteases regulate many biological processes and are prominent targets for therapeutic intervention. Structural studies have captured intermediates along the reaction pathway, including the Michaelis complex and tetrahedral intermediate. Using a Ramachandran analysis of these structures, we discovered that residues occupying the P1 and P1′ positions (which flank the scissile peptide bond) adopt the dihedral angle of an inverse γ-turn and polyproline type-II helix, respectively. Computational analyses reveal that the polyproline type-II helix engenders an n→π* interaction in which the oxygen of the scissile peptide bond is the donor. This interaction stabilizes the negative charge that develops in the tetrahedral intermediate, much like the oxyanion hole of serine proteases. The inverse γ-turn serves to twist the scissile peptide bond, vacating the carbonyl π* orbital and facilitating its hydration. These previously unappreciated interactions entail a form of substrate-assisted catalysis and offer...
Site-Specific K63 Ubiquitinomics Provides Insights into Translation Regulation under Stress.

During oxidative stress, K63-linked polyubiquitin chains modify a variety of proteins including ribosomes. Knowledge of the precise sites of K63 ubiquitin is key to understand its function during the response to stress. To identify the sites of K63 ubiquitin, we developed a new mass spectrometry based method that quantified >1100 K63 ubiquitination sites in yeast that responded to oxidative stress induced by H2O2. We determined that under stress, K63 ubiquitin-modified proteins were involved in several cellular functions including ion transport, protein trafficking, and translation. The most abundant ubiquitin sites localized to the head of the 40S subunit of the ribosome, modified assembled polysomes, and affected the binding of translation factors. The results suggested a new pathway of post-initiation control of translation during oxidative stress and illustrated the importance of high-resolution mapping of noncanonical ubiquitination events.
Significant Others, or Textual Congress: Concerning Baudelaire and Tranter

This essay is a three step investigation of the relation between two poems, Baudelaire’s “L’Invitation au Voyage”, and the Australian poet John Tranter’s “Grab Your Passport”. The first step reject...
Predicting success in regulatory approval from phase I results.

2556 Background: Drug development in oncology is resource intensive and has a high failure rate. In this exploratory analysis, we aimed to identify the characteristics and outcomes of Phase I studi...
In the uncanny valley, transportation predicts narrative enjoyment more than empathy, but only for the tragic hero

Abstract The uncanny valley is a term used to describe the phenomenon that human simulations that are nearly but not quite realistic often give viewers an uneasy, eerie feeling. Given the prevalence of computer-animated human characters and a narrative framework in videogames, serious games, and health-related scenarios, it is important to examine how the uncanny valley influences narrative empathy and enjoyment. In a 2 × 2 × 2 between-groups posttest-only experiment, 738 participants took the role of a patient in a virtual consultation with a doctor; the consultation varied in the doctor's character (hero or villain), its subplot ending (happy or tragic), and its depiction (computer animated or real). The participants' posttest results showed greater emotional empathy and enjoyment in the hero condition and no significant difference in emotional empathy for the computer animation but greater narrative enjoyment and persuasion. Just endings (hero rewarded, villain punished) elicited much greater pleasure than unjust endings. In comparing computer animation with recorded video, emotional empathy was a significantly stronger predictor of narrative enjoyment than transportation only for the real hero with a tragic ending. The enjoyment and persuasiveness of the computer-animated doctor–patient consultation bodes well for the use of animation in interactive visual narratives.
Core-Shell Modeling of Light Scattering by Vesicles: Effect of Size, Contents, and Lamellarity

Having a fast, reliable method for characterizing vesicles is vital for their use as model cell membranes in biophysics, synthetic biology, and origins of life studies. Instead of the traditionally used Rayleigh-Gans-Debye approximation, we use an exact extended Lorenz-Mie solution for how core-shell particles scatter light to model vesicle turbidity. This approach enables accurate interpretations of simple turbidimetric measurements and is able to accurately model highly scattering vesicles, such as larger vesicles, those with multiple layers, and those with encapsulated material. We uncover several surprising features, including that vesicle lamellarity has a larger effect on sample turbidity than vesicle size and that the technique can be used to measure the membrane thickness of vesicles. We also examine potential misinterpretations of turbidimetry and discuss when measurements are limited by forward and multiple scattering and by the geometry of the instrument.
Tropical Storms and Mortality under Climate Change

Abstract Extreme weather induced by climate change can have major consequences for human health. In this study, I quantify the effect of tropical storm frequency and severity on mortality using objective meteorological data and the universe of vital statistics records from a large developing country, Mexico. Using a measure of storm exposure that accounts for both windspeed dispersion and population density along the storm track, I project changes in past storm-related mortality under various scenarios of continued climate change, while holding population and income at contemporaneous levels. I find that storm-related deaths would have risen under most climate change scenarios considered, with increases of as much as 52% or declines of as much as 10%, depending on the interplay between increasing storm severity and decreased frequency.
Convex coding

Inspired by recent work on convex formulations of clustering (Lashkari & Golland, 2008; Nowozin & Bakir, 2008) we investigate a new formulation of the Sparse Coding Problem (Olshausen & Field, 1997). In sparse coding we attempt to simultaneously represent a sequence of data-vectors sparsely (i.e. sparse approximation (Tropp et al., 2006)) in terms of a "code" defined by a set of basis elements, while also finding a code that enables such an approximation. As existing alternating optimization procedures for sparse coding are theoretically prone to severe local minima problems, we propose a convex relaxation of the sparse coding problem and derive a boosting-style algorithm, that (Nowozin & Bakir, 2008) serves as a convex "master problem" which calls a (potentially non-convex) sub-problem to identify the next code element to add. Finally, we demonstrate the properties of our boosted coding algorithm on an image denoising task.
Chapter 3 – Calculus

Chapter 3 introduces Mathematica's calculus capabilities. The examples used to illustrate the various functions are similar to examples typically seen in a traditional calculus sequence. If you have trouble typing commands correctly, use the buttons on the Basic Math Input or Basic Math Assistant palettes to help you create templates in standard mathematical notation that you can evaluate.
The Global Kinematics of the Globular Cluster M92

We report the determination of high-accuracy radial velocities for 306 members of the globular cluster M92 using the Hydra multiobject spectrograph on the WIYN telescope. We have concentrated on stars outside of the central region of the cluster, located up to 14.4' from the cluster center. Candidate members were selected for spectroscopy based on a photometric metallicity index determined from three-band Washington photometry, also obtained with the WIYN telescope. The median error in the velocities is 0.35 km s-1. We find the heliocentric radial velocity of the cluster to be -121.2 ± 0.3 km s-1. We have used an improved Bayesian analysis to determine the velocity dispersion profile of M92. The most probable profile is a cored power law with a scale radius of 2', a velocity dispersion at 1' of 6.3 km s-1, and an outer power law with a slope of -0.6. We have also reanalyzed the M15 radial velocities of Drukier et al. and find that a pure power law with a 1' velocity dispersion of 8 km s-1 and a slope of -0.5 and the combination of a power law with a slope of -0.4 and a scale of 7.5 km s-1 inside 9' and a dispersion of 4 km s-1 outside are equally likely. In both clusters there is evidence that the samples include escaping stars. We present results from a GRAPE-based N-body simulation of an isolated cluster that demonstrates this effect. We suggest additional tests to determine the relative importance of tidal heating and stellar ejection for establishing the velocity field in globular cluster halos.
Advanced low-noise aircraft configurations and their assessment: past, present, and future

Aircraft noise remains the key inhibitor of the growth of air transportation, but the focus of the noise mitigation strategies has changed. As the propulsor fan pressure ratio is decreased for improved fuel burn and lessened environmental impact, the propulsion system noise can be reduced near or even below the noise level of the airframe. Jet noise has become less of a concern, and during approach and landing, the acoustic signature is predominantly set by the airframe. Novel aircraft concepts and architectures, enabled by distributed, more integrated, and boundary-layer ingesting propulsion systems, pose new aeroacoustic problems which require innovative approaches and call for teaming and collaboration as the technological challenges cut across disciplines. One past example of such a collaborative research effort was the Silent Aircraft Initiative (SAI), aimed at the conceptual design of an aircraft imperceptible to the human ear outside the airport perimeter. The initiative brought together researchers from academia, industry, and government agencies. This chapter gives a brief summary of the Silent Aircraft Initiative, the SAX-40 aircraft design, and the noise reduction technologies which were pursued. A decade past SAI, novel aircraft architectures such as the D8 double bubble aircraft, the outcome of a joint effort between MIT, Aurora Flight Sciences and Pratt and Whitney, are being pursued in the quest of reducing the climate impact of aviation. With regulations continuing to reduce the allowable aviation noise emission levels, both new challenges and new opportunities are emerging. Electric, hybrid, and turbo-electric aircraft concepts are currently being investigated as potential game changers. Independent of the level of electrification, noise will remain a major issue as air transportation is growing and mobility might become a key driver. The chapter discusses a selection of enabling technologies and their implications on acoustics and noise and gives a perspective on future trends and new directions in aeroacoustics required to address the challenges.
Enhancing the electrical and thermal conductivities of polymer composites via curvilinear fibers: An analytical study:

The new generation of manufacturing technologies such as additive manufacturing and automated fiber placement has enabled the development of material systems with desired functional and mechanical properties via particular designs of inhomogeneities and their mesostructural arrangement. Among these systems, particularly interesting are materials exhibiting curvilinear transverse isotropy (CTI), in which the inhomogeneities take the form of continuous fibers following curvilinear paths designed to, for example, optimize the electric and thermal conductivity, and the mechanical performance of the system. In this context, the present work proposes a general framework for the exact, closed-form solution of electrostatic problems in materials featuring CTI. First, the general equations for the fiber paths that optimize the electric conductivity are derived, leveraging a proper conformal coordinate system. Then, the continuity equation for the curvilinear transversely isotropic system is derived in terms of ele...
Prisoners of the Wrong Dilemma: Why Distributive Conflict, Not Collective Action, Characterizes the Politics of Climate Change

Climate change policy is generally modeled as a global collective action problem structured by free-riding concerns. Drawing on quantitative data, archival work, and elite interviews, we review emp...
Submodular Cost Submodular Cover with an Approximate Oracle.

In this work, we study the Submodular Cost Submodular Cover problem, which is to minimize the submodular cost required to ensure that the submodular benefit function exceeds a given threshold. Existing approximation ratios for the greedy algorithm assume a value oracle to the benefit function. However, access to a value oracle is not a realistic assumption for many applications of this problem, where the benefit function is difficult to compute. We present two incomparable approximation ratios for this problem with an approximate value oracle and demonstrate that the ratios take on empirically relevant values through a case study with the Influence Threshold problem in online social networks.
Dendralene-Type TTF Vinylogs Containing a 1,3-Diselenole Ring

2-Diformylmethylene-1,3-diselenole was prepared and condensed with dithiolium phoshonium bromides and dithiolium phosphonates in the presence of base to give dendralene-type vinylogs of TTF bearing a 1,3-diselenole moiety. The electrochemistry of these dendrimers was studied. SEEPR measurements were also carried out. Calculations were carried out on the radical cations and correlated with the EPR values.
The phosphorus-Claisen condensation

Abstract 1,1-Bisphosphorus compounds are easily synthesized through the phosphorus-Claisen (phospha-Claisen) condensation between a phosphorus-stabilized anion and a phosphorus electrophile. The preliminary scope of this reaction is investigated in terms of employable phosphorus reagents. Valuable intermediates are conveniently prepared in a single step. Overall, the method is competitive with multistep procedures which require the preparation of PCl intermediates derived from the P(OR) reagents we instead employ directly, and it delivers complex organophosphorus compounds in moderate to good isolated yields. An example of the intramolecular version of the reaction, the phospha-Dieckmann condensation, is also reported.
Dimerization of o-hydroxycyclohexadienones related to calicheamicinone: SN2 displacement of the 12α-hydroxyl group

Abstract Deprotection of the readily available bicyclo[7.3.1]enediyne alcohol 14 resulted in dimerization to give 18. Replacement of the 12α-hydroxyl group with a p-methoxyanilino group proceeded with overall retention to give 23 which also produced a dimer on attempted deprotection.
A Fundamentally New, Simple, Stereospecific Synthesis of Oligosaccharides Containing the β-Mannopyranosyl and β-Rhamnopyranosyl Linkage

The important role of oligosaccharides in biological processes1 has been recognized for a long time. Consequently, synthetic oligosaccharides have become indispensable probes for the life sciences.2 Methods for the chemical synthesis of oligosaccharides are based on a two-step process: The first comprises activation of the anomeric center to generate a glycosyl donor, and the second is its transfer to a glycosyl acceptor. The stereochemical outcome of the reaction depends on complex stereoelectronic effects as well as the presence or absence of groups at O-2 in the glycosyl donor capable of neighboring group participation.3 Except for rare cases, when the coupling of a glycosyl donor and a glycosyl acceptor occurs as an almost entirely SN2 process,4 the reaction of the glycosyl donor involves the formation of the oxocarbenium ion (1). Thus, the nonstereospecificity of glycosylation is virtually inherent in the method.
Actin assembly and non-muscle myosin activity drive dendrite retraction in an UNC-6/Netrin dependent self-avoidance response

Dendrite growth is constrained by a self-avoidance response that induces retraction but the downstream pathways that balance these opposing mechanisms are unknown. We have proposed that the diffusible cue UNC-6(Netrin) is captured by UNC-40(DCC) for a short-range interaction with UNC-5 to trigger self-avoidance in the C. elegans PVD neuron. Here we report that the actin-polymerizing proteins UNC-34(Ena/VASP), WSP-1(WASP), UNC-73(Trio), MIG-10(Lamellipodin) and the Arp2/3 complex effect dendrite retraction in the self-avoidance response mediated by UNC-6(Netrin). The paradoxical idea that actin polymerization results in shorter rather than longer dendrites is explained by our finding that NMY-1 (non-muscle myosin II) is necessary for retraction and could therefore mediate this effect in a contractile mechanism. Our results also show that dendrite length is determined by the antagonistic effects on the actin cytoskeleton of separate sets of effectors for retraction mediated by UNC-6(Netrin) versus outgrowth promoted by the DMA-1 receptor. Thus, our findings suggest that the dendrite length depends on an intrinsic mechanism that balances distinct modes of actin assembly for growth versus retraction.
Gold- and silver-mediated cycloisomerizations of N-propargylamides.

Substituted N-propargylamides have proven to be valuable substrates for alkyne-activated cycloisomerization reactions. N-Tosyl-N′-propargylurea underwent reaction with AuCl3 to give the corresponding dihydroimidazolone, while N-propargyl-3-oxobutanamides and esters were used to construct furanyl fused pyrrolidinones and dihydrofuranones via Ag(I)-mediated alkyne activation.
First highly enantioselective epoxidation of alkenes with aldehyde/Oxone® ☆

Optically active aldehydes have been successfully used as catalysts for asymmetric epoxidations of unfunctionalized alkenes (ee up to 94%) by using Oxone® as the oxygen source. Experimental results indicate that the in-situ-generated aldehyde dioxirane is responsible for this catalytic activity.
Palladium-catalyzed cross-coupling of aryldiazonium tetrafluoroborate salts with arylboronic esters

Abstract A novel palladium-catalyzed reaction of aryldiazonium tetrafluoroborate salts with arylboronic esters furnishes cross-coupled products in moderate yields. The reaction proceeds at relatively mild temperatures and in aqueous media.
Design, synthesis, and evaluation of octahydropyranopyrrole-based inhibitors of mammalian ribonucleotide reductase

Abstract Inhibitors of mammalian ribonucleotide reductase possessing a novel octahydropyranopyrrole scaffold based on a cyclic heptapeptide inhibitor have been designed, synthesized, and evaluated. Structure–function studies reveal that the bicyclic scaffold is indeed necessary to maintain inhibitory activity.
A new allenic Pauson-Khand cycloaddition for the preparation of α-methylene cyclopentenones

Abstract Alkynyl allenes undergo an intramolecular molybdenum-mediated Pauson-Khand cycloaddition to provide functionalized α-methylene cyclopentenones in one step.
Reactions of (Triphenylsilyl)ethylene Oxide with Grignard Reagents (and with MgBr2). A Reinvestigation

Reactions of (triphenylsilyl)ethylene oxide (1) with simple Grignard reagents such as EtMgBr and PhMgBr have been reported to yield crystalline hydroxysilanes assigned as the α-hydroxy silanes expected from β opening of the epoxide. Reinvestigation of these reactions showed that the hydroxysilanes were the β-hydroxy silanes 4 and 7 expected from a rearrangement−trapping sequence; a bromohydrin, assigned as the α-bromo-β-hydroxy silane 9 from α opening, and (triphenylsilyl)acetaldehyde (8) were also formed.
Solution-phase parallel synthesis of 115 homosilatecan analogues

The parallel synthesis of 115 homosilatecans on 1−5 mg scale has been accomplished. Key reactions include N-propargylation of a common iodopyridone lactone with a silyl-substituted propargyl bromide, followed by cascade radical annulation with a substituted isonitrile. Simple manual techniques for parallel reactions were coupled with automated purifications (SPE, HPLC) to give high-purity final products. The speed and simplicity of the automated purification protocol more than compensated for yield losses in the synthesis of some analogues relative to traditional flash chromatographic purifications.
Entertainment Design in Mixed Martial Arts: Does Cage Size Matter?

This paper investigates the effect of a change in cage size on fighter performance outcomes in Zuffa-owned mixed martial arts (MMA) promotions. Variation in cage size is observed through different events over time in the Ultimate Fighting Championship (UFC) and World Extreme Cagefighting (WEC). Results suggest that smaller cages lead to more fight finishes (knockouts and submissions) and higher rates of distance knockdowns and choke attempts, all exciting outcomes for viewers. But they also lead to a higher proportion of time with fighters pressed against the cage, a position some viewers may dislike. Since MMA promoters com-pete with other forms of entertainment, findings have strategic implications for promoter cage-size decisions. Subscribe to JASM