cssi/SciSciGPT-SciSciNet huggingface dataset:
What Are the Primary Concerns of Recently Graduated Surgeons and How Do They Differ From Those of the Residency Training Years

Hypothesis Graduated surgeons have differences in concerns when comparisons are made between fellows and practicing surgeons, practicing surgeons and residents, and male and female surgeons. Design and Setting A survey was distributed to surgeons who graduated from 17 New England residency programs from 1993 to 1996, consisting of 9 demographic questions and 33 items coded on a Likert-type scale (with scores from 1 [least concerning] to 5 [most concerning]). Participants Surgical fellows and practicing surgeons recently graduated from general surgical residency programs in New England who had participated in a previous study as residents. Intervention Distribution and completion of the survey. Main Outcome Measure Personal and career-oriented concerns of recently graduated surgical residents. Results Personal issues continue to rank high for graduated residents, but the areas of greatest concern became more financially and career oriented. The top concerns of fellows were personal finances (mean score, 3.2), child rearing (mean score, 3.1), salary (mean score, 3.1), postponing family plans (mean score, 3.0), availability of role models (mean score, 2.9), and number of work hours (mean score, 2.8). The top concerns of practicing surgeons were salary (mean score, 3.2), personal finances (mean score, 3.1), number of referrals (mean score, 3.0), support for research (mean score, 2.7), child rearing (mean score, 2.7), and availability of role models (mean score, 2.7). Differences existed between men and women for child rearing, initiating personal relationships, maintaining personal relationships, maternity leave, and promotional advancement. Women were more concerned than men. Conclusions Assistance with career planning and job selection during the residency years should be enhanced to diminish the concerns about financial issues and the availability of role models after graduation. Many of the concerns among male and female graduates are still reflective of larger societal expectations, but some, such as promotional advancement, may be attenuated through guidance and mentoring of residents before job selection.
On the design of large flexible space structures (LFSS)

For a general finite-element model of an LFSS, a strictly passive compensator results in an exponentially stable feedback system when actuators and sensors are colocated. In the general case (no colocation) we state necessary and sufficient conditions on the parameter Q for stabilizing a certain number of modes. We give conditions for robust stability and show that feedback does not destabilize the unmodeled modes under certain conditions.
Harmonizing the RR Lyrae and Clump Distance Scales-Stretching the Short Distance Scale to Intermediate Ranges?

I explore the consequences of making the RR Lyrae and clump giant distance scales consistent in the solar neighborhood, Galactic bulge and Large Magellanic Cloud (LMC). I employ two major assumptions: (1) that the absolute magnitude -metallicity, M{sub V}(RR) - [Fe/H], relation for RR Lyrae stars is universal, and (2) that absolute I-magnitudes of clump giants, M{sub I}(RC), in Baade's Window can be inferred from the local Hipparcos calibration of clump giants' magnitudes. A comparison between the solar neighborhood and Baade's Window sets M{sub V}(RR) at [Fe/H] = -1.6 in the range (0.59 {+-} 0.05, 0.70 {+-} 0.05), somewhat brighter than the statistical parallax solution. A comparison between Baade's Window and the LMC sets the M{sub I}{sup LMC}(RC) in the range (-0.33 {+-} 0.09, -0.53 {+-} 0.09). The distance modulus to the LMC is {mu}{sup LMC} {element_of} (18.24 {+-} 0.08, 18.44 {+-} 0.07). I argue that the currently available information slightly favors the short distance scale but is insufficient to select the correct solutions with high confidence.
Does a Lack of Health Insurance Elicit an Increase in the Rate of Voluntary Military Enlistment in the U.S.? The “Military Health Care Magnet Hypothesis,” 1974-2007

This study addresses a question that has not been researched much previously, namely, does the unavailability of health insurance act as an incentive for persons to enlist in the military in the U.S.? This relationship is proffered as the “Military Health Care Magnet Hypothesis.” The present study endeavors to provide insight into this issue within a cost-benefit framework. The empirical analysis uses annual data for the years 1974 through 2007, the only years to date for which all of the variables in the model are dependable after the end of military conscription in the U.S. in 1973. Both OLS and 2SLS results demonstrate, among other things, that the greater the percentage of the civilian population without health insurance, the greater the rate of enlistment in the U.S. Army.
Cloud and Radiative Balance Changes in Response to ENSO in Observations and Models

AbstractThe authors use observations and four GFDL AGCMs to analyze the relation between variations in spatial patterns and area-averaged quantities in the top-of-the-atmosphere radiative fluxes, cloud amount, and precipitation related to El Nino over the period 1979–2008. El Nino is associated with an increase in tropical average sea surface temperature of order +0.1 K (with a maxima of +0.5 K), large local anomalies of +2 K (maxima +6 K), and tropical tropospheric warming of +0.5 K (maxima +1 K). The authors find that model-to-observation biases in the base state translate into corresponding biases in anomalies in response to El Nino. The pattern and amplitude of model biases in reflected shortwave (SW) and outgoing longwave radiation (OLR) follows expectations based on their biases in cloud amount: models with a positive cloud amount bias, compared to observations, have too strong local responses to El Nino in cloud amount, SW, OLR, and precipitation.Tropical average OLR increases in response to El Nin...
Designing Perpetual Conservation Agreements for Land Management

Conservation initiatives on working ranches balance flexibility for land management with restrictions to ensure protection over time. Conservation easements are a common tool for range conservation, but the perpetual nature of their individually negotiated rights and restrictions may present a challenge for adaptive land management. The evolution of conservation easement approaches to land management was addressed in a review of 52 grazing easements created by The Nature Conservancy (TNC) in California rangelands between 1973 and 2006 as well as through interviews with TNC staff. Easement terms related to land management increased in complexity over time, particularly for purchased easements on private land. Easements commonly contained restrictions on riparian or wetland management (58%), residual dry matter (50%), and type of animal permitted (46%) but rarely restricted number of cattle or animal unit months (4%). Flexibility was provided by easement terms such as exceptions for drought years and reference to best management practices, the easement holder's administrative discretion, and easement amendment. Interviews with TNC staff revealed an iterative process in which conservation easements remain relatively fixed once they are established, whereas subsequent easements incorporate lessons learned from easement monitoring, enforcement, management, and applicable science. Conservation easements with an adaptive approach would link compliance terms with conservation goals, require monitoring of those terms, and have a mechanism for altering land management based on monitoring results. All three of these realms present challenges for the conservation easement structure. Improvements could be made in easement terms, ecological monitoring, and stewardship to improve the effectiveness and adaptability of this tool for maintaining ecological function on working ranches.
The Black-White Test Score Gap Through Third Grade

This article describes basic facts regarding the Black-White test score gap over the first four years of school. Black children enter school substantially behind their White counterparts in reading and math, but including a small number of covariates erases the gap. Over the first four years of school, however, Blacks lose substantial ground relative to other races; averaging 0.10 standard deviations per school year. By the end of third grade, there is a large Black-White test score gap that cannot be explained by observable characteristics. Blacks are falling behind in virtually all categories of skills tested, except the most basic. None of the explanations we examine, including systematic differences in school quality across races, convincingly explain the divergent academic trajectory of Black students.
PHOTOCHEMICAL DEPROTECTION OF 3',5'-DIMETHOXYBENZOIN (DMB) CARBAMATES DERIVED FROM SECONDARY AMINES

Abstract Treatment of secondary amines with a (dimethoxybenzoin)carbonylimidazolium salt provides dimethoxybenzoin carbamates that can be deprotected photochemically.
Phase clocks for transient fault repair

Phase clocks are synchronization tools that implement a form of logical time in distributed systems. For systems tolerating transient faults by self-repair of damaged data, phase clocks can enable reasoning about the progress of distributed repair procedures. This paper presents a phase clock algorithm suited to the model of transient memory faults in asynchronous systems with read/write registers. The algorithm is self-stabilizing and guarantees accuracy of phase clocks within O(k) time following an initial state that is.
The better you are the stronger it makes you: Evidence on the asymmetric impact of liberalization

Abstract This paper shows how trade liberalization can have an asymmetric effect on heterogeneous firms. It develops a neo-Schumpeterian growth model predicting that the impact of liberalization on economic performance is positive “on average”, but more advanced firms benefit more. These predictions are tested using Mexican plant-level data confirming that, under NAFTA, the liberalization spurred productivity growth on average. However, the empirical analysis goes beyond estimating the average effect of liberalization and shows that more advanced firms benefited disproportionately more from the liberalization. Focusing on the mechanisms explaining these results, the paper shows that the results are not just driven by an increase in input usage and investments, but rather by innovative and managerial efforts as they are significantly stronger in those sectors where the scope for innovative activities is larger.
Vinyl imidates in cycloaddition reactions: synthesis of (±)-alloyohimbane

The intramolecular Diels–Alder reaction of N-acylvinyl imidates provides a rapid entry into cis-fused hexahydroisoquinolones. This methodology has been used in a concise synthesis of the yohimbine alkaloid (±)-alloyohimbane.
The epidemic of esophageal adenocarcinoma

The incidence and mortality related to esophageal adenocarcinoma (EAC) have been increasing in the United States, several European countries, and Oceania for the past 2 to 3 decades. Survival remains dismal, with little improvement during the same time period. Variations in the coding, classification, and detection of gastroesophageal malignancy may have contributed partially to the observed trends. Remarkable differences related to gender, ethnicity, and geography characterize the epidemiology of EAC. Gastroesophageal reflux disease (GERD) is the main risk factor for Barrett's esophagus, which is the only known precursor lesion for EAC. Several risk factors that promote the development of GERD and/or Barrett's esophagus have been proposed to explain these rising trends; these factors include the declining rates of Helicobacter pylori infection, obesity, dietary factors, and certain drugs.
Immunohistochemical localization of C9 neoantigen and the terminal complement inhibitory protein CD59 in human endometrium.

PROBLEM: Human endometrium expresses complement components, receptors, and regulatory proteins, many of which appear to be expressed in a hormone-dependent manner. Whether terminal complement components are also present in the endometrium is unknown. CD59, a broadly expressed protein that blocks association of C9 with C8 in the membrane attack complex, is localized in reproductive tissue to human spermatozoa, seminal plasma, amniotic fluid, and placenta. The present study examines human endometrium for the presence of CD59 and terminal complement proteins. METHOD: Endometrial biopsies were obtained from six normal women from various phases of the menstrual cycle and analyzed by immunohistochemistry, using MEM-43 anti-human CD59 and anti-human SC5b-9 murine monoclonal antibodies and the immunoperoxidase technique. RESULTS: Both CD59 protein and SC5b-9 (C9 neoantigen) were demonstrated to be present in endometrial glandular epithelium throughout the menstrual cycle. No specific staining was demonstrated in the stromal compartment. CONCLUSION: CD59 protein and terminal complement proteins are expressed in glandular epithelial cells of normal human endometrium, in both proliferative and luteal phases, suggesting that expression is not hormonally dependent. These analyses further support the presence of a functionally active complement system in normal human endometrium.
Stereocontrolled Glycoside and Glycosyl Ester Synthesis. Neighboring Group Participation and Hydrogenolysis of 3-(2‘-Benzyloxyphenyl)-3,3-dimethylpropanoates

The 2-O-[3-(2‘-benzyloxyphenyl)-3,3-dimethylpropanoate] and 2-O-[3-(2‘-benzyloxy-4‘,6‘-dimethylphenyl)-3,3-dimethylpropanoate] esters enable the synthesis of a range of β-glucosides and α-mannosides through neighboring participation in excellent yield, and are removed by hydrogenolysis in concert with the cleavage of benzyl esters in the presence of other esters making them particularly well suited to the stereocontrolled synthesis of glycosyl esters.
RECENT RESULTS IN MATHEMATICAL GR

The current state of the vacuum evolution problem in general relativity is reviewed from a perspective of rigorous mathematical results.
An experimental investigation of flutter of a fully submerged subcavitating hydrofoil

Abstract : Experimental results are reported of an investigation of the flutter characteristics of a fully submerged subcavitating hydrofoil. The foil suffered a catastrophic flutter failure at a speed of approximately 48 knots. Comparisons are made with various prediction methods, neither the two- dimensional nor the three-dimensional theoretical calculations yielding results of the correct order of magnitude. Calculations employing measured three- dimensional oscillatory coefficients give a highly conservative prediction for flutter speed.
A new approach to fault-tolerant wormhole routing for mesh-connected parallel computers

A new method for fault-tolerant wormhole routing in arbitrary dimensional meshes is introduced. The method was motivated by certain routing requirements of an initial design of the Blue Gene supercomputer at IBM Research. The machine is organized as a three-dimensional mesh containing many thousands of nodes and the routing method should tolerate a few percent of the nodes being faulty. There has been much work on routing methods for meshes that route messages around faults or regions of faults. The new method is to declare certain nonfaulty nodes to be "lambs." A lamb is used for routing but not processing, so a lamb is neither the source nor the destination of a message. The lambs are chosen so that every "survivor node," a node that is neither faulty nor a lamb, can reach every survivor node by at most two rounds of dimension-ordered (such as e-cube) routing. An algorithm for finding a set of lambs is presented. The results of simulations on 2D and 3D meshes of various sizes with various numbers of random node faults are given. For example, on a 32 /spl times/ 32 /spl times/ 32 3D mesh with 3 percent random faults and using at most two rounds of e-cube routing for each message, the average number of lambs is less than 68, which is less than 7 percent of the number 983 of faults and less than 0.21 percent of the number 32,768 of nodes.
Dynamics and control of robotic systems worn by humans

A description is given of the dynamics, control, and stability of extenders, robotic systems worn by humans for material handling tasks. Extenders are defined as robot manipulators which extend the strength of the human arm in load maneuvering tasks, while the human maintains control of the task. Part of the extender motion is caused by physical power from the human; the rest of the extender motion results from force signals measured at the physical interfaces between the human and the extender, and the load and the extender. Therefore, the human wearing the extender exchanges both power and information signals with the extender. The control technique described lets the designer define an arbitrary relationship between the human force and the load force. Experiments on a two-dimensional non-direct-drive extender were done to verify the control theory. >
Adaptive Experimental Design for Construction of Response Surface Approximations

Sequential Approximate Optimization (SAO) is a class of methods available for the multidisciplinary design optimization (MDO) of complex systems that are composed of several disciplines coupled together. One of the approaches used for SAO, is based on a quadratic response surface approximation, where zero and first order information are required. In these methods, designers must generate and query a database of order O(n2) in order to compute the second order terms of the quadratic response surface approximation. As the number of design variables grows, the computational cost of generating the required database becomes a concern. In this paper, we present an new approach in which we require just O(ri) parameters for constructing a second order approximation. This is accomplished by transforming the matrix of second order terms into the canonical form. The method periodically requires an order O(n2) update of the second order approximation to maintain accuracy. Results show that the proposed approach is practical and convenient for engineering design problems by dramatically reducing the total number of calls to the simulation tools.
Boundary recursion for descriptor variable systems

It is shown that if an n-dimensional descriptor variable system satisfies the properties of solvability and controllability, the family of solutions is n-dimensional and the set of two-point boundary values that are consistent with the system can be expressed as the solutions to a linear system of equations involving only the boundary values. This equation is termed a boundary mapping equation and it provides a compact representation of the system. The boundary mapping generalizes the state-transition matrix associated with state variable systems. The author presents the boundary mapping theory, describes the recursive processes required, and applies both to some special cases, including general linear time-invariant systems and adjoint systems. >
Building from the bottom up

Abstract Designed materials and new tools hold the key for future science and technologies. Building materials from the bottom up is complementary to traditional top-down materials processing, but requires a deep understanding of the individual molecular structures, their assemblies, and dynamic behaviors. This approach, using molecular self-assembly as a fabrication tool, will become an integral part of materials production, especially nanomaterials, in the coming years. Two key elements in molecular self-assembly are chemical complementarity and structural compatibility through weak and noncovalent interactions. We have defined the path to understand these principles. The self-assembly systems represent a significant advance in the molecular engineering of advanced materials and nanomaterials. Nature is a grand master who builds materials from the bottom up, one atom or molecule at a time. These materials include inorganic minerals, crystals, clays, inorganic/organic composite seashells, pearls, bone and teeth, wood, silk, horn, collagen, and extracellular matrices. The sophistication of nature’s bottom-up fabrication and construction has inspired us to learn, in order to go beyond nature’s materials.
Normal changes of aging and their impact on care of the older surgical patient.

Patients 65 years of age or older constitute a large part of the perioperative population. Because the older patient's physiology is unique, it is essential that health care providers recognize the normal physiology of aging and be able to differentiate normal changes of aging from those of pathology. The normal changes of aging result in the older patient presenting differently with specific care needs. Care to this older population must be individualized by providers who are familiar with geriatrics in order to enhance outcomes.
Stable non-N-heterocyclic carbenes (non-NHC): recent progress

This account summarizes the results that have been obtained by our group since 2000 in the area of stable singlet acyclic carbenes. It includes aryl- and alkyl-(phosphino)carbenes, aryl(amino)carbenes, and (amino)(phosphino)carbenes. Our most recent achievements, the transformation of stable carbenes into other stable carbenes are also discussed, along with preliminary results concerning the ligand properties of these species.
Performance of the MISR LAI and FPAR algorithm: a case study in Africa

The Multi-angle Imaging SpectroRadiometer (MISR) instrument is designed to provide global imagery at nine discrete viewing angles and four visible/near-infrared spectral bands. The MISR standard products include green leaf area index (LAI) of vegetation and fraction of photosynthetically active radiation absorbed by vegetation (FPAR). These parameters are being routinely processed from MISR data at the Langley Atmospheric Sciences Data Center (ASDC) since October 2002. This paper describes the research basis for transitioning the MISR LAI/FPAR product from beta to provisional status. The quality and spatial coverage of MISR land surface reflectances that are input to the algorithm determine the quality and spatial coverage of the LAI and FPAR products. Therefore, considerable efforts have been expended to analyze the performance of the algorithm as a function of uncertainties of MISR surface reflectances and to establish the convergence property of the MISR LAI/FPAR algorithm, namely, that the reliability and accuracy of the retrievals increase with increased input information content and accuracy. An additional objective of the MISR LAI/FPAR algorithm is classification of global vegetation into biome types—information that is usually an input to remote sensing algorithms that use single-angle observations. An upper limit of uncertainties of MISR surface reflectances that allows discrimination between biomes, minimizes the impact of biome misidentification on LAI retrievals, and maximizes the spatial coverage of retrievals was estimated. Algorithm performance evaluated on a limited set of MISR data from Africa suggests valid LAI retrievals and correct biome identification in about 20% of the pixels, on an average, given the current level of uncertainties in the MISR surface reflectance data. The other 80% of the LAI values are retrieved using incorrect information about the type of biome. However, the use of multi-angle data minimizes the impact of biome misidentification on LAI retrievals; that is, with a probability of about 70%, uncertainties in LAI retrievals due to biome misclassification do not exceed uncertainties in the observations. We also discuss in depth the parameters that characterize LAI/FPAR product quality—such as quality assessment (QA) that is available to the users along with the product. The analysis of the MISR LAI/FPAR product presented here demonstrates the physical basis of the radiative transfer algorithm used in the retrievals and, importantly, that the reliability and accuracy of the retrievals increase with increased input information content and accuracy. Further improvements in the quality of MISR surface reflectances are therefore expected to lead to LAI and FPAR retrievals of increasing quality.
From the Boltzmann equation to fluid mechanics on a manifold

We apply the Chapman–Enskog procedure to derive hydrodynamic equations on an arbitrary surface from the Boltzmann equation on the surface.
Poly(A)-tail profiling reveals an embryonic switch in translational control

Poly(A) tails enhance the stability and translation of most eukaryotic mRNAs, but difficulties in globally measuring poly(A)-tail lengths have impeded greater understanding of poly(A)-tail function. Here, we describe poly(A)-tail length profiling by sequencing (PAL-seq) and apply it to measure tail lengths of millions of individual RNAs isolated from yeasts, cell lines, Arabidopsis leaves, mouse liver, and zebrafish and frog embryos. Poly(A)-tail lengths were conserved between orthologous mRNAs, with mRNAs encoding ribosomal proteins and other “housekeeping” proteins tending to have shorter tails. As expected, tail lengths were coupled to translational efficiency in early zebrafish and frog embryos. However, this strong coupling diminished at gastrulation and was absent in non-embryonic samples, indicating a rapid developmental switch in the nature of translational control. This switch complements an earlier switch to zygotic transcriptional control and explains why the predominant effect of microRNA-mediated deadenylation concurrently shifts from translational repression to mRNA destabilization.
Quantum information processing, operational quantum logic, convexity, and the foundations of physics

Abstract Quantum information science is a source of task-related axioms whose consequences can be explored in general settings encompassing quantum mechanics, classical theory, and more. Quantum states are compendia of probabilities for the outcomes of possible operations we may perform on a system: “operational states.” I discuss general frameworks for “operational theories” (sets of possible operational states of a system), in which convexity plays key role. The main technical content of the paper is in a theorem that any such theory naturally gives rise to a “weak effect algebra” when outcomes having the same probability in all states are identified and in the introduction of a notion of “operation algebra” that also takes account of sequential and conditional operations. Such frameworks are appropriate for investigating what things look like from an “inside view,” i.e., for describing perspectival information that one subsystem of the world can have about another. Understanding how such views can combine, and whether an overall “geometric” picture (“outside view”) coordinating them all can be had, even if this picture is very different in structure from the perspectives within it, is the key to whether we may be able to achieve a unified, “objective” physical view in which quantum mechanics is the appropriate description for certain perspectives, or whether quantum mechanics is truly telling us we must go beyond this “geometric” conception of physics.
The Lecture Hall Parallelepiped

The s-lecture hall polytopes P s are a class of integer polytopes defined by Savage and Schuster which are closely related to the lecture hall partitions of Eriksson and Bousquet-Melou. We define a half-open parallelopiped Par s associated with P s and give a simple description of its integer points. We use this description to recover earlier results of Savage et al. on the δ-vector (or h*-vector) and to obtain the connections to s-ascents and s-descents, as well as some generalizations of these results.
Multiplicative bidding in online advertising

In this paper, we initiate the study of the multiplicative bidding language adopted by major Internet search companies. In multiplicative bidding, the effective bid on a particular search auction is the product of a base bid and bid adjustments that are dependent on features of the search (for example, the geographic location of the user, or the platform on which the search is conducted). We consider the task faced by the advertiser when setting these bid adjustments, and establish a foundational optimization problem that captures the core difficulty of bidding under this language. We give matching algorithmic and approximation hardness results for this problem; these results are against an information-theoretic bound, and thus have implications on the power of the multiplicative bidding language itself. Inspired by empirical studies of search engine price data, we then codify the relevant restrictions of the problem, and give further algorithmic and hardness results. Our main technical contribution is an O(log n)-approximation for the case of multiplicative prices and monotone values. We also provide empirical validations of our problem restrictions, and test our algorithms on real data against natural benchmarks. Our experiments show that they perform favorably compare with the baseline.
Spin Gradient Demagnetization Cooling of Ultracold Atoms

We demonstrate a new cooling method in which a time-varying magnetic field gradient is applied to an ultracold spin mixture. This enables preparation of isolated spin distributions at positive and negative effective spin temperatures of $\ifmmode\pm\else\textpm\fi{}50\text{ }\mathrm{pK}$. The spin system can also be used to cool other degrees of freedom, and we have used this coupling to cool an apparently equilibrated Mott insulator of rubidium atoms to 350 pK. These are the lowest temperatures ever measured in any system. The entropy of the spin mixture is in the regime where magnetic ordering is expected.
Issues and R&D critical to the LCLS

The Linac Coherent Light Source (LCLS) [1] is a high brightness X-ray free-electron laser project based on the SLAC linac. A new photocathode rf gun serves as injector for the last kilometer of the linac, which is fitted with two-stages of bunch compression. Acceleration to 15-GeV produces intense 1.5-/spl Aring/ coherent radiation by self-amplified spontaneous emission in a long undulator. A multi-laboratory project collaboration is addressing the most challenging issues, including: (1) feasibility of a stable injector with normalized emittance of 1 /spl mu/m at 1 nC; (2) emittance control in the linac including effects of coherent synchrotron radiation in the bunch compressors; (3) stability of the final electron beam in the presence of charge, timing, and energy variations; (4) design, construction and alignment of a long planar undulator with 3-cm period and discrete periodic focusing lattice; (5) understanding and control of wakefields due to wall surface roughness in the undulator vacuum chamber; (6) radiation-matter interactions in the strong field regime with mirror and crystal optics for filtering and deflecting. These issues, and a project update, are presented.
Cryptographic hardness for learning intersections of halfspaces

We give the first representation-independent hardness results for PAC learning intersections of halfspaces, a central concept class in computational learning theory. Our hardness results are derived from two public-key cryptosystems due to Regev, which are based on the worst-case hardness of well-studied lattice problems. Specifically, we prove that a polynomial-time algorithm for PAC learning intersections of n^@e halfspaces (for a constant @e>0) in n dimensions would yield a polynomial-time solution to [email protected]?(n^1^.^5)-uSVP (unique shortest vector problem). We also prove that PAC learning intersections of n^@e low-weight halfspaces would yield a polynomial-time quantum solution to [email protected]?(n^1^.^5)-SVP and [email protected]?(n^1^.^5)-SIVP (shortest vector problem and shortest independent vector problem, respectively). Our approach also yields the first representation-independent hardness results for learning polynomial-size depth-2 neural networks and polynomial-size depth-3 arithmetic circuits.
ALIGNMENT OF PROTOSTARS AND CIRCUMSTELLAR DISKS DURING THE EMBEDDED PHASE

Star formation proceeds via the collapse of a molecular cloud core over multiple dynamical timescales. Turbulence within cores results in a spatially non-uniform angular momentum of the cloud, causing a stochastic variation in the orientation of the disk forming from the collapsing material. In the absence of star-disk angular momentum coupling, such disk-tilting would provide a natural mechanism for the production of primordial spin-orbit misalignments in the resulting planetary systems. However, owing to high accretion rates in the embedded phase of star formation, the inner edge of the circumstellar disk extends down to the stellar surface, resulting in efficient gravitational and accretional angular momentum transfer between the star and the disk. Here, we demonstrate that the resulting gravitational coupling is sufficient to suppress any significant star-disk misalignment, with accretion playing a secondary role. The joint tilting of the star-disk system leads to a stochastic wandering of star-aligned bipolar outflows. Such wandering widens the effective opening angle of stellar outflows, allowing for more efficient clearing of the remainder of the protostar's gaseous envelope. Accordingly, the processes described in this work provide an additional mechanism responsible for sculpting the stellar initial mass function.
Microwave-assisted Hantzsch thiazole synthesis of N-phenyl-4-(6-phenylimidazo[2,1-b]thiazol-5-yl)thiazol-2-amines from the reaction of 2-chloro-1-(6-phenylimidazo[2,1-b]thiazol-5-yl)ethanones and thioureas.

Abstract N -Phenyl-4-(6-phenylimidazo[2,1- b ]thiazol-5-yl)thiazol-2-amines ( 6a–q ) have been synthesized by the Hantzsch thiazole reaction of 2-chloro-1-(6-phenylimidazo[2,1- b ]thiazol-5-yl)ethanones ( 4a–e ) with suitably substituted thioureas using microwave heating. The ethanones ( 4a–e ) were prepared by the reaction of 6-phenylimidazo[2,1- b ]thiazoles ( 3a–e ) with chloroacetylchloride in refluxing 1,4-dioxane whereas the thiazoles ( 3a–e ) were synthesized by the reaction of 2-bromo-1-phenylethanones ( 2a–e ) with thiazol-2-amine in refluxing acetone.
DE SITTER MUSINGS

We discuss some of the issues arising when considering asymptotically de Sitter space–times and attempts to address them. Our development begins at the classical level where several initial value problems are discussed and ends with several proposals for holography in asymptotically de Sitter space–times. Throughout the paper we give a review of some basic notions such as the geometry of Schwarzschild–de Sitter black hole, the Nariai limit and quantum field theory in a fixed de Sitter background. We also briefly discuss some semiclassical aspects such as the nucleation of black holes and the Hartle–Hawking wavefunctional. We end by giving an overview of some open questions. An emphasis is placed on the differences between a static patch observer confined to live in a thermal cavity and the metaobserver who has access to a finite region of the future boundary.
Cryptographic Complexity of Multi-Party Computation Problems: Classifications and Separations

We develop new tools to study the relative complexities of secure multi-party computation tasks in the Universal Composition framework. When one task can be securely realized using another task as a black-box, we interpret this as a qualitative, complexity-theoretic reduction between the two tasks. Virtually all previous characterizations of MPC functionalities, in the UC model or otherwise, focus exclusively on secure function evaluation. In comparison, the tools we develop do not rely on any special internal structure of the functionality, thus applying to functionalities with arbitrary behavior. Our tools additionally apply uniformly to both the PPT and unbounded computation models. Our first main tool is an exact characterization of realizability in the UC framework with respect to a large class of communication channel functionalities. Using this characterization, we can rederive all previously-known impossibility results as immediate and simple corollaries. We also complete the combinatorial characterization of 2-party secure function evaluation initiated by [12] and partially extend the combinatorial conditions to the multi-party setting. Our second main tool allows us to translate complexity separations in simpler MPC settings (such as the honest-but-curious corruption model) to the standard (malicious) setting. Using this tool, we demonstrate the existence of functionalities which are neither realizable nor complete, in the unbounded computation model.
Many-body force and mobility measurements in colloidal systems

We demonstrate a technique for simultaneously measuring each component of the force vectors and mobility tensor of a small collection of colloidal particles based on observing a set of particle trajectories. For a few-body system of micron-sized polymer beads in oil separated by several particle radii, we find that the mobility tensor is well-described by a pairwise Stokeslet model. This stands in contrast to the electrostatic interactions, which were found to deviate significantly from a pairwise model. The measurement technique presented here should be simple to extend to systems of heterogeneous, non-spherical particles arranged in arbitrary three dimensional geometries.
Ruthenium-Catalyzed Cycloisomerization−6π-Cyclization: A Novel Route to Pyridines

Herein we report a method for the synthesis of substituted pyridines. The unsaturated ketones and aldehydes derived from the cycloisomerization of primary and secondary propargyl diynols in the pre...
Application of Artificial Neural Networks to the Design of Turbomachinery Airfoils

The feasibility of applying artie cial neural networks to the aerodynamic design of turbomachinery airfoils is investigated. The design process involves dee ning a target pressure distribution, computing several e ows to adequately populate the design space in the vicinity of the target, training the neural network with this data, and, e nding a design that has a pressure distribution that is closest to the target. The last step is carried out using the network as a function evaluator. This design process is tested using an established e ow simulation procedure, a simple two-layer feedforward network and a conjugate gradient optimization technique. Results are presented for some validation tests as well as a complete design effort where the pressure distribution from a modern Pratt and Whitneyturbinewasused as a target. Theseresultsareveryencouraging and clearly warrant furtherdevelopment of the process for full three-dimensional design.
Numerical simulation of chemical vapor deposition processes under variable and constant property approximations

The chemical vapor deposition (CVD) process for silicon, using silane (SiH4) with hydrogen (H2) as the carrier gas, is modeled numerically using constant properties evaluated at various reference temperatures T r e f. Results are compared with those from a numerical model based on variable transport properties. When the susceptor is isothermally heated, deposition rates predicted by the simplified model agree very well (5% error) with the variable property solution. A susceptor heated by means of a uniform heat flux input has a large temperature variation across the susceptor surface, yielding considerable error from the constant property model. However, a carefully chosen T r e f for cases with large heat flux input, which gives rise to diffusion-controlled deposition (surface Damkohler number Das >> 1), is able to capture property variation effects and predict the deposition rate with reasonable accuracy. A variable property model is necessary at low heating rates, since reaction-controlled deposi...
Global Issues and Local Action: The Rights to Intellectual Freedom and Information Access, and What That Means for U.S. Libraries

Discussions regarding intellectual freedom, censorship, and information access are nothing new. The explosive rise of information and communication technologies (ICTs) and the almost instantaneous connections that can be and are formed from opposite sides of the world, between individuals with no prior contact and perhaps little in common besides access to communication devices, lead to the necessity to reevaluate how we view intellectual freedom and information access as human rights, particularly as rights that enable democratic growth. Are these rights universal, or are they merely cultural imperatives – and how should the distinction determine our actions as librarians? How vital are rights to intellectual freedom and information access in the creation and maintenance of democratic societies? What can we learn from recent events, particularly the 2011 Egyptian revolution and the Occupy Wall Street movement? Finally, how can libraries and librarians in the United States act locally – both politically and practically – to foster these freedoms globally?
Phosphine-Directed C ? H Borylation Reactions: Facile and Selective Access to Ambiphilic Phosphine Boronate Esters

Ambiphilic ligands have received considerable attention over the last two decades due to their unique reactivity as organocatalysts and ligands. The iridium-catalyzed C-H borylation of phosphines is described in which the phosphine is used as a directing group to provide selective formation of arylboronate esters with unique scaffolds of ambiphilic compounds. A variety of aryl and benzylic phosphines were subjected to the reaction conditions, selectively providing stable, isolable boronate esters upon protection of the phosphine as the borane complex. After purification, the phosphine-substituted boronate esters could be deprotected and isolated in pure form.
God, The Devil, And Gödel

Descartes believed that (nonhuman) animals were essentially machines, but that humans were obviously not; for a machine could never use speech or other signs as we do when placing our thoughts on record for the benefit of others. ... it never happens that (a beast) arranges its speech in various ways, in order to reply appropriately to everything that may be said in its presence, as even the lowest type of man can do. (1) Descartes argued that Beasts were machines, because, like machines, they lacked certain capabilities of humans. La Mettrie accepted Descartes’ reasoning. (2) But he disagreed about what machines could do. He felt that a machine could be constructed to do anything that a man could do and thus agreed that a man too was a machine. Descartes’s argument took an obvious, well-proven fact about men (their speaking ability) and argued that machines did not have this ability. It’s not obvious that he established his point about machines for it’s not obvious that machines must fail where it is indeed obvious that men succeed. And, as we saw, La Mettrie, for one, was unconvinced to the extent that he turned Descartes’ arguments back upon him and, accepting Descartes’ test, argued that man was a machine, for he believed that machines could be constructed to pass the test. So things were once more at a standstill. In this paper, I concern myself with a similar claim but one placed in a different philosophical climate. Like Descartes, John Lucas (3) (and others) has argued that man couldn’t be a machine for (he argues) man can do something which has been shown by Godel to be beyond the reach of machines. The case is slightly different from Descartes’since Descartes had, of course, nothing resembling a proof that machines were incapable of man’s linguistic behaviour. Remember La Mettrie. Perhaps our latter-day Cartesian has finally struck the mark for now it has been shown that certain machines are logically precluded from succeeding at certain tasks. If it can be shown that man can perform these tasks, then the issue is settled once and for all.
An SL(2, Z) multiplet of type IIB superstrings

An SL(2, Z) family of string solutions of type IIB supergravity in ten dimensions is constructed. The solutions are labeled by a pair of relatively prime integers, which characterize charges of the three-form field strengths. The string tensions depend on these charges in an SL(2, Z) covariant way. Compactifying on a circle and identifying with eleven-dimensional supergravity compactified on a torus implies that the modulus of the IIB theory should be equated to the modular parameter of the torus.
H.263 to VP6 video transcoder

VP6 is a video coding standard developed by On2 Technologies. It is the preferred codec in the Flash 8/9 format used by many popular online video services and user generated content sites. The wide adoption of Flash video for video delivery on the Internet has made VP6 one of the most widely used video compression standards on the Internet. With the wide adoption of VP6 comes the need for transcoding other video formats to the VP6 format. This paper presents algorithms to transcode H.263 to the VP6 format. This transcoder has applications in media adaptation including converting older Flash video formats to Flash 8 format. The transcoding algorithms reuse the information from the H.263 decoding stage and accelerate the VP6 encoding stage. Experimental results show that the proposed algorithms are able to reduce the encoding complexity by up to 52% while reducing the PSNR by at most 0.42 dB in the worst case.
Observation of Orbital Angular Momentum Transfer between Acoustic and Optical Vortices in Optical Fiber

Acousto-optic interaction in optical fiber is examined from the perspective of copropagating optical and acoustic vortex modes. Calculation of the acousto-optic coupling coefficient between different optical modes leads to independent conservation of spin and orbital angular momentum of the interacting photons and phonons. We show that the orbital angular momentum of the acoustic vortex can be transferred to a circularly polarized fundamental optical mode to form a stable optical vortex in the fiber carrying orbital angular momentum. The technique provides a useful way of generating stable optical vortices in the fiber medium.
Oxidative folding of proteins.

The oxidative folding of proteins is reviewed and illustrated with bovine pancreatic ribonuclease A (RNase A). The mutual effects of conformational folding and disulfide bond regeneration are emphasized, particularly the “locking in” of native disulfide bonds by stable tertiary structure in disulfide intermediates. Two types of structured metastable disulfide species are discerned, depending on the relative protection of their disulfide bonds and thiol groups. Four generic pathways for oxidative folding are identified and characterized.
Technology Shocks, Technological Collaboration, and Innovation Outcomes

In the early to mid-1990s, technology alliances suddenly surged to unprecedented levels-roughly 300% growth per year from 1990 to 1995-and then declined just as precipitously. This massive increase in alliance activity caused the crystallization of a giant component in the global technology network that connected a large portion of the world's firms, government labs, universities, and other organizations. However, when alliance activity declined, the component disintegrated. What caused this spike in alliance activity? And did this large-but-transient change in collaboration activity leave any enduring effect? The data here suggest that a major technology shock may have provoked this alliance surge. A technology shock may simultaneously unleash significant innovation opportunities while creating great uncertainty in the economic environment. Though it is well known that firms often use alliances both to respond to uncertainty and facilitate innovation, little is known about how technology shocks affect the collaboration behavior of firms and how these two factors separately influence innovation outcomes. I integrate an inductive study of collaboration activity and a technology shock with existing research on economics, alliances, and networks to build a set of arguments about how technology shocks will influence alliance behavior, how changes in alliance behavior will influence the global technology collaboration network, and about how each of these changes is likely to influence the innovative outcomes of firms. I then explore the separate and joint effects of the technology shock and collaboration activity on innovation using a large sample panel study of patenting by North American firms.