cssi/SciSciGPT-SciSciNet huggingface dataset:
The current and emerging role of cardiovascular magnetic resonance imaging in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy and the leading cause of sudden death in young people and a major cause of heart failure symptoms at any age. Due to its genetic etiology, there is substantial heterogeneity in the phenotypic expression and clinical course of patients with HCM. Traditionally, two-dimensional echocardiography has been the easiest and reliable technique for establishing a diagnosis of HCM. However, cardiovascular magnetic resonance (CMR) has emerged as a novel, 3-dimensional tomographic imaging technique, which provides high spatial and temporal resolution images of the heart (not limited by thoracic or pulmonary parenchyma), in any plane and without ionizing radiation. As a result, CMR is particularly well suited to provide detailed characterization of the HCM phenotype, including a precise assessment of the location and distribution of LV wall thickening (as well as other myocardial structures such as the right ventricle and papillary muscles). In this regard, CMR has been demonstrated to provide a diagnosis of HCM in cases where the echocardiogram was non-diagnostic. Furthermore, CMR provides an accurate assessment of total LV mass which is a more robust marker of hypertrophy, with potential implications for risk stratification. In addition, with the intravenous administration of gadolinium, first-pass perfusion sequences can identify myocardial perfusion abnormalities, while late gadolinium enhancement sequences can identify areas of myocardial fibrosis/scarring. Although the clinical implications of late gadolinium enhancement in HCM are still uncertain this information may, in the near-future, have important implications with regard to identifying HCM patients at high risk of sudden death and progressive heart failure, including evolution into the end-stage phase of HCM. Therefore, at present, CMR provides important information impacting on diagnosis and clinical management strategies in patients with HCM and will likely have an expanding role in the evaluation of patients with this complex disease.
Ruthenium(0) Catalyzed Endiyne-α-Ketol [4 + 2] Cycloaddition: Convergent Assembly of Type II Polyketide Substructures via C-C Bond Forming Transfer Hydrogenation.

Upon exposure of 3,4-benzannulated 1,5-diynes (benzo-endiynes) to α-ketols (α-hydroxyketones) in the presence of Ru(0) catalysts derived from Ru3(CO)12 and RuPhos or CyJohnPhos, successive redox-triggered C–C coupling occurs to generate products of [4 + 2] cycloaddition. The proposed catalytic mechanism involves consecutive alkyne-carbonyl oxidative couplings to form transient oxaruthanacycles that suffer α-ketol mediated transfer hydrogenolysis. This process provides a new, convergent means of assembling Type II polyketide substructures.
Computerized semiautomated microbiological assay of folacin

A semiautomated microbiological folacin assay system is described. A microcomputer controls sample dilutions, medium addition, turbidity determination, and data acquisition. Assay capacity is 600 tubes per day, approximately twice that of comparable manual assays. Using the automated equipment, more samples can be compared within one assay, eliminating many sources of between-assay variation in large studies. Additional advantages of this system are reduced human errors, flexibility of assay design, and multifunctional component equipment. Folacin results from chicken liver, spinach, and breakfast cereal samples show equivalent precision for manual and automated assays.
Degenerate Operators and the $1/c$ Expansion: Lorentzian Resummations, High Order Computations, and Super-Virasoro Blocks

One can obtain exact information about Virasoro conformal blocks by analytically continuing the correlators of degenerate operators. We argued in recent work that this technique can be used to explicitly resolve information loss problems in AdS3/CFT2. In this paper we use the technique to perform calculations in the small 1/c ∝ G N expansion: (1) we prove the all-orders resummation of logarithmic factors $$ \propto \frac{1}{c} \log\;z $$ in the Lorentzian regime, demonstrating that 1/c corrections directly shift Lyapunov exponents associated with chaos, as claimed in prior work, (2) we perform another all-orders resummation in the limit of large c with fixed cz, interpolating between the early onset of chaos and late time behavior, (3) we explicitly compute the Virasoro vacuum block to order 1/c 2 and 1/c 3 with external dimensions fixed, corresponding to 2 and 3 loop calculations in AdS3, and (4) we derive the heavy-light vacuum blocks in theories with $$ \mathcal{N} $$ = 1, 2 superconformal symmetry.
Price elasticities of pharmaceuticals in a value based-formulary setting.

Empirical estimates of price elasticities of demand (PED) for pharmaceuticals suggest that they are relatively price inelastic. However, in many settings, a medication and its substitutes and complements face simultaneous differential changes in prices that affect the observed "composite" PED. We exploit an implementation of a value-based formulary (VBF) that utilized drug-specific incremental cost-effectiveness ratios (ICERs) to inform drug copayments, resulting in increases in copayments for some medications and decreases in copayments for others. We first show theoretically that by changing the price of a medication and its substitute in opposite directions, VBF designs can leverage cross-price effects to increase the range of composite PEDs. We then empirically estimate PED and welfare effects using a consumer surplus approach. Overall PED was -0.16, similar to the RAND Health Insurance Experiment estimate. However, there was substantial dispersion of PED across the VBF copayment tiers ranging from -0.09 to -0.87 with a statistically significant trend aligned with the levels of value as reflected by the ICER estimates (p < 0.001). The net welfare increase was $147,000 for the cohort or $28 per member over the postpolicy year. Further experimentations of VBF designs with alternative cost-effectiveness thresholds, copayment levels and value definitions could be quite promising for improving welfare.
Regioselective Ring Opening of Di-isopropylsilylenes Derived from 1,3-Diols with Alkyl Lithium Reagents

The selective alkyl lithium-induced ring opening of 1,3-di-isopropylsilylenes is described. The reaction affords a differentially substituted 1,3-diol bearing a silane that resides at the oxygen in the more sterically demanding position. The reaction can be highly selective with a regiochemical preference up to >50:1 and likely proceeds via an alkoxy-silane intermediate. This intermediate can by trapped by methyl iodide to provide the corresponding silyl methyl ether, wherein the silane again resides at the oxygen in the more sterically demanding position.
Determining Driver Phone Use by Exploiting Smartphone Integrated Sensors

This paper utilizes smartphone sensing of vehicle dynamics to determine driver phone use, which can facilitate many traffic safety applications. Our system uses embedded sensors in smartphones, i.e., accelerometers and gyroscopes, to capture differences in centripetal acceleration due to vehicle dynamics. These differences combined with angular speed can determine whether the phone is on the left or right side of the vehicle. Our low infrastructure approach is flexible with different turn sizes and driving speeds. Extensive experiments conducted with two vehicles in two different cities demonstrate that our system is robust to real driving environments. Despite noisy sensor readings from smartphones, our approach can achieve a classification accuracy of over 90 percent with a false positive rate of a few percent. We also find that by combining sensing results in a few turns, we can achieve better accuracy (e.g., 95 percent) with a lower false positive rate. In addition, we seek to exploit the electromagnetic field measurement inside a vehicle to complement vehicle dynamics for driver phone sensing under the scenarios when little vehicle dynamics is present, for example, driving straight on highways or standing at roadsides.
Testing a Moderated Mediation Model of Transformational Leadership, Values, and Organization Change

A field study of organizational leaders and their immediate followers was conducted to investigate (a) the mediating roles of follower openness to change values and follower self-transcendence valu...
Two Round Multiparty Computation via Multi-key FHE

We construct a general multiparty computation MPC protocol with only two rounds of interaction in the common random string model, which is known to be optimal. In the honest-but-curious setting we only rely on the learning with errors LWE assumption, and in the fully malicious setting we additionally assume the existence of non-interactive zero knowledge arguments NIZKs. Previously, Asharov et al. EUROCRYPT '12 showed how to achieve three rounds based on LWE and NIZKs, while Garg et al. TCC '14 showed how to achieve the optimal two rounds based on indistinguishability obfuscation, but it was unknown if two rounds were possible under standard assumptions without obfuscation. Our approach relies on multi-key fully homomorphic encryption MFHE, introduced by Lopez-Alt et al. STOC '12, which enables homomorphic computation over data encrypted under different keys. We present a construction of MFHE based on LWE that significantly simplifies a recent scheme of Clear and McGoldrick CRYPTO '15. We then extend this construction to allow for a one-round distributed decryption of a multi-key ciphertext. Our entire MPC protocol consists of the following two rounds:1.Each party individually encrypts its input under its own key and broadcasts the ciphertext. All parties can then homomorphically compute a multi-key encryption of the output.2.Each party broadcasts a partial decryption of the output using its secret key. The partial decryptions can be combined to recover the output in plaintext.
Embryonic Ethanol Exposure Dysregulates BMP and Notch Signaling, Leading to Persistent Atrio-Ventricular Valve Defects in Zebrafish.

Fetal alcohol spectrum disorder (FASD), birth defects associated with ethanol exposure in utero, includes a wide spectrum of congenital heart defects (CHDs), the most prevalent of which are septal and conotruncal defects. Zebrafish FASD model was used to dissect the mechanisms underlying FASD-associated CHDs. Embryonic ethanol exposure (3–24 hours post fertilization) led to defects in atrio-ventricular (AV) valvulogenesis beginning around 37 hpf, a morphogenetic event that arises long after ethanol withdrawal. Valve leaflets of the control embryos comprised two layers of cells confined at the compact atrio-ventricular canal (AVC). Ethanol treated embryos had extended AVC and valve forming cells were found either as rows of cells spanning the AVC or as unorganized clusters near the AV boundary. Ethanol exposure reduced valve precursors at the AVC, but some ventricular cells in ethanol treated embryos exhibited few characteristics of valve precursors. Late staged larvae and juvenile fish exposed to ethanol during embryonic development had faulty AV valves. Examination of AVC morphogenesis regulatory networks revealed that early ethanol exposure disrupted the Bmp signaling gradient in the heart during valve formation. Bmp signaling was prominent at the AVC in controls, but ethanol-exposed embryos displayed active Bmp signaling throughout the ventricle. Ethanol exposure also led to mislocalization of Notch signaling cells in endocardium during AV valve formation. Normally, highly active Notch signaling cells were organized at the AVC. In ethanol-exposed embryos, highly active Notch signaling cells were dispersed throughout the ventricle. At later stages, ethanol-exposed embryos exhibited reduced Wnt/β-catenin activity at the AVC. We conclude that early embryonic ethanol exposure alters Bmp, Notch and other signaling activities during AVC differentiation leading to faulty valve morphogenesis and valve defects persist in juvenile fish.
Will Global Warming Make Hurricane Forecasting More Difficult

AbstractHurricane track forecasts have improved steadily over the past few decades, yet forecasting hurricane intensity remains challenging. Of special concern are the rare instances of tropical cyclones that intensify rapidly just before landfall, catching forecasters and populations off guard, thereby risking large casualties. Here, we review two historical examples of such events and use scaling arguments and models to show that rapid intensification just before landfall is likely to become increasingly frequent and severe as the globe warms.
Laser Damage Comparisons of Broad-Bandwidth High-Reflection Optical Coatings Containing TiO2 Nb2O5 or Ta2O5 High Index Layers.

Broad bandwidth coatings allow angle of incidence flexibility and accommodate spectral shifts due to aging and water absorption. Higher refractive index materials in optical coatings, such as TiO2, Nb2O5, and Ta2O5, can be used to achieve broader bandwidths compared to coatings that contain HfO2 high index layers. We have identified the deposition settings that lead to the highest index, lowest absorption layers of TiO2, Nb2O5, and Ta2O5, via e-beam evaporation using ion-assisted deposition. We paired these high index materials with SiO2 as the low index material to create broad bandwidth high reflection coatings centered at 1054 nm for 45 deg angle of incidence and P polarization. High reflection bandwidths as large as 231 nm were realized. Laser damage tests of these coatings using the ISO 11254 and NIF-MEL protocols are presented, which revealed that the Ta2O5/SiO2 coating exhibits the highest resistance to laser damage, at the expense of lower bandwidth compared to the TiO2/SiO2 and Nb2O5/SiO2 coatings.
Why Don't Commercial Health Plans Use Prospective Payment?

One of the key terms in contracts between hospitals and insurers is how the parties apportion the financial risk of treating unexpectedly costly patients. “Prospective” payment contracts give hospi...
Strongly Maximal Intersection-Complete Neural Codes on Grids are Convex

Abstract The brain encodes spatial structure through a combinatorial code of neural activity. Experiments suggest such codes correspond to convex areas of the subject’s environment. We present an intrinsic condition that implies a neural code may correspond to a collection of convex sets and give a bound on the minimal dimension underlying such a realization.
Assessing Fair Lending Risks Using Race/Ethnicity Proxies

Fair lending analysis of nonmortgage credit products often involves proxying for race/ethnicity since such information is not required to be reported. Using mortgage data, this paper evaluates a series of proxy approaches geo, surname, geo-surname, and Bayesian Improved Surname Geocoding BISG as compared with the race/ethnicity reported under the Home Mortgage Disclosure Act HMDA. The BISG proxy predicts the reported race/ethnicity the best as judged by prediction bias, correlation coefficient, and discriminatory power. In assessing fair lending risks where classification of race/ethnicity is called for, we propose the BISG maximum classification, which produces a more accurate estimation of mortgage pricing disparities than the current practices. The above conclusions withhold various robustness tests. Additional analysis is performed to assess the proxies on nonmortgage credits by leveraging consumer credit bureau data. This paper was accepted by Amit Seru, finance.
Blind Estimation of Sparse Multi-User Massive MIMO Channels

Author(s): Mezghani, Amine; Swindlehurst, A Lee | Abstract: We provide a maximum likelihood formulation for the blind estimation of massive mmWave MIMO channels while taking into account their underlying sparse structure. The main advantage of this approach is the fact that the overhead due to pilot sequences can be reduced dramatically especially when operating at low SNR per antenna. Thereby, the sparsity in the angular domain is exploited as a key property to enable the unambiguous blind separation between user's channels. On the other hand, as only the sparsity is assumed, the proposed method is robust with respect to the statistical properties of the channel and data and allows the estimation in rapidly time-varying scenarios and eventually the separation of interfering users from adjacent base stations. Additionally, a performance limit is derived based on the clairvoyant Cram #x27;er Rao lower bound. Simulation results demonstrate that this maximum likelihood formulation yields superior estimation accuracy with reasonable computational complexity and limited model assumptions.
Do what i want, not what i did: Imitation of skills by planning sequences of actions

We propose a learning-from-demonstration approach for grounding actions from expert data and an algorithm for using these actions to perform a task in new environments. Our approach is based on an application of sampling-based motion planning to search through the tree of discrete, high-level actions constructed from a symbolic representation of a task. Recursive sampling-based planning is used to explore the space of possible continuous-space instantiations of these actions. We demonstrate the utility of our approach with a magnetic structure assembly task, showing that the robot can intelligently select a sequence of actions in different parts of the workspace and in the presence of obstacles. This approach can better adapt to new environments by selecting the correct high-level actions for the particular environment while taking human preferences into account.
A Distributed Algorithm for Solving a Linear Algebraic Equation

A distributed algorithm is described for solving a linear algebraic equation of the form $Ax = b$ assuming the equation has at least one solution. The equation is simultaneously solved by $m$ agents assuming each agent knows only a subset of the rows of the partitioned matrix $[\matrix{A & b}]$ , the current estimates of the equation's solution generated by its neighbors, and nothing more. Each agent recursively updates its estimate by utilizing the current estimates generated by each of its neighbors. Neighbor relations are characterized by a time-dependent directed graph $\BBN(t)$ whose vertices correspond to agents and whose arcs depict neighbor relations. It is shown that for any matrix $A$ for which the equation has a solution and any sequence of “repeatedly jointly strongly connected graphs” $\BBN(t)$ , $t = 1, 2, \ldots$ , the algorithm causes all agents' estimates to converge exponentially fast to the same solution to $Ax = b$ . It is also shown that, under mild assumptions, the neighbor graph sequence must actually be repeatedly jointly strongly connected if exponential convergence is to be assured. A worst case convergence rate bound is derived for the case when $Ax = b$ has a unique solution. It is demonstrated that with minor modification, the algorithm can track the solution to $Ax = b$ , even if $A$ and $b$ are changing with time, provided the rates of change of $A$ and $b$ are sufficiently small. It is also shown that in the absence of communication delays, exponential convergence to a solution occurs even if the times at which each agent updates its estimates are not synchronized with the update times of its neighbors. A modification of the algorithm is outlined which enables it to obtain a least squares solution to $Ax = b$ in a distributed manner, even if $Ax = b$ does not have a solution.
Perceived emotional social support in bereaved spouses mediates the relationship between anxiety and depression.

Abstract Background Prior research has shown that anxiety symptoms predict later depression symptoms following bereavement. Nevertheless, no research has investigated mechanisms of the temporal relationship between anxiety and later depressive symptoms or examined the impact of depressive symptoms on later anxiety symptoms following bereavement. Methods The current study examined perceived emotional social support as a possible mediator between anxiety and depressive symptoms in a bereaved sample of older adults (N =250). Anxiety and depressive symptoms were measured at Wave 1 (immediately after bereavement), social support was measured at Wave 2 (18 months after bereavement), and anxiety and depressive symptoms were also measured at Wave 3 (48 months after bereavement). Results Using Bayesian structural equation models, when controlling for baseline depression, anxiety symptoms significantly positively predicted depressive symptoms 48 months later, Further, perceived emotional social support significantly mediated the relationship between anxiety symptoms and later depressive symptoms, such that anxiety symptoms significantly negatively predicted later emotional social support, and emotional social support significantly negatively predicted later depressive symptoms. Also, when controlling for baseline anxiety, depressive symptoms positively predicted anxiety symptoms 48 months later. However, low emotional social support failed to mediate this relationship. Conclusions Low perceived emotional social support may be a mechanism by which anxiety symptoms predict depressive symptoms 48 months later for bereaved individuals.
Gutenberg–Richter law for deep earthquakes revisited: A dual-mechanism hypothesis

Deep earthquake b values appear to vary with slab thermal state and earthquake magnitude. The physical reason for the variations and the relation with deep rupture mechanisms are still unclear. Here I confirm the spatial variations of b value and the dependence on slab temperature using about 40 yr of data from the Global Centroid Moment Tensor catalog. A new bimodal pattern is observed for the 500–700 km depth range: b is close to 1 in the cold Tonga slab, while in warmer slabs (e.g., South America, Japan–Kuril, Izu–Bonin–Mariana), b is close to 0.5 for intermediate magnitudes (M_w 5.3–6.5) and increases to ∼1 for large magnitudes (M_w > 6.5). To explain these observations, I propose a dual-mechanism hypothesis in which deep earthquakes nucleate only within the metastable olivine wedge (MOW), but can rupture outside MOW by a different mechanism. The fractal dimension of earthquake size distribution changes from 2 to 1 as the thermally controlled MOW thickness decreases, and back to 2 as the mechanism outside MOW dominates.
Psychometric Evaluation of the Occupation-Centered Intervention Assessment

A challenge of intervention research is the lack of a means to identify and measure clinical practice from an occupation-centered approach. The objective of this study is to establish basic psychometric properties of the Occupation-Centered Intervention Assessment (OCIA). The study is approached by establishing content validity and utility through expert panel and two focus groups. Interrater reliability (IRR) was determined through standardized video analysis and Krippendorff's alpha. Results from the expert panel and focus groups indicated an overall agreement that the OCIA was able to capture the full range of elements of rehabilitation-focused interventions for older adults (occupational, contextual, and personal relevance) and a good fit with the occupational therapy intervention process model. IRR found adequate level of agreement (α = .76). The OCIA has demonstrated initial basic psychometrics for observation of rehabilitation-focused interventions with older adults.
Low-frequency surface wave propagation and the viscoelastic behavior of porcine skin

A physical model describing the propagation of low- frequency surface waves in relation to the viscoelastic behavior of porcine skin is presented, along with a series of empirical studies testing the performance of the model. The model assumes that the skin behaves as a semi-infinite, locally isotropic, viscoelastic half- space. While the assumption of a semi-infinite body is violated, this violation does not appear to have a significant impact on the perfor- mance of the model based on the empirical studies. 1-Hz surface waves in the skin propagate primarily as Rayleigh waves with a wave- length and velocity of approximately 3 m and 3.0 m/s, respectively. The amplitude of the acoustic wave, as measured by tracking the acoustic stress wave-induced shift in a backscattered laser speckle pattern, decreases exponentially with lateral distance from the acous- tic source. Using this model of surface wave propagation, the me- chanical loss factor or tan d of the skin is measured to be on the order of 0.1460.07. The results presented are consistent with earlier works on the propagation of low-frequency acoustic waves in biological tis- sues, and should serve as a theoretical and empirical basis for using the wave characteristics of propagating surface waves in combination with the mechanical behavior of the tissue for biomechanical studies and for potential diagnostic applications. © 2004 Society of Photo-Optical
Throughput-Optimal Scheduling for Multi-Hop Networked Transportation Systems With Switch-Over Delay

The emerging connected-vehicle technology provides a new dimension for developing more intelligent traffic control algorithms for signalized intersections. An important challenge for scheduling in networked transportation systems is the switchover delay caused by the guard time before any traffic signal change. The switch-over delay can result in significant loss of system capacity and hence needs to be accommodated in the scheduling design. To tackle this challenge, we propose a distributed online scheduling policy that extends the well-known Max-Pressure policy to address switch-over delay by introducing a bias factor favoring the current schedule. We prove that the proposed policy is throughput-optimal with switch-over delay. Furthermore, the proposed policy remains optimal when there are both connected signalized intersections and conventional fixed-time ones in the system. With connected-vehicle technology, the proposed policy can be easily incorporated into the current transportation systems without additional infrastructure. Through extensive simulation in VISSIM, we show that our policy indeed outperforms the existing popular policies.
The dependence of effective planning horizon on model accuracy

Because planning with a long horizon (i.e., looking far into the future) is computationally expensive, it is common in practice to save time by using reduced horizons. This is usually understood to come at the expense of computing suboptimal plans, which is the case when the planning model is exact. However, when the planning model is estimated from data, as is frequently true in the real world, the policy found using a shorter planning horizon can actually be better than a policy learned with the true horizon. In this paper we provide a precise explanation for this phenomenon based on principles of learning theory. We show formally that the planning horizon is a complexity control parameter for the class of policies available to the planning algorithm, having an intuitive, monotonic relationship with a simple measure of complexity. We prove a planning loss bound predicting that shorter planning horizons can reduce overfitting and improve test performance, and we confirm these predictions empirically.
Generalized Irreducible Divisor Graphs

In 1988, Beck introduced the notion of a zero-divisor graph of a commutative rings with 1. There have been several generalizations in recent years. In particular, in 2007 Coykendall and Maney developed the irreducible divisor graph. Much work has been done on generalized factorization, especially τ-factorization. The goal of this paper is to synthesize the notions of τ-factorization and irreducible divisor graphs in domains. We will define a τ-irreducible divisor graph for nonzero non unit elements of a domain. We show that, by studying τ-irreducible divisor graphs, we find equivalent characterizations of several finite τ-factorization properties.
Large-scale evolution of image classifiers

Neural networks have proven effective at solving difficult problems but designing their architectures can be challenging, even for image classification problems alone. Our goal is to minimize human participation, so we employ evolutionary algorithms to discover such networks automatically. Despite significant computational requirements, we show that it is now possible to evolve models with accuracies within the range of those published in the last year. Specifically, we employ simple evolutionary techniques at unprecedented scales to discover models for the CIFAR-10 and CIFAR-100 datasets, starting from trivial initial conditions and reaching accuracies of 94.6% (95.6% for ensemble) and 77.0%, respectively. To do this, we use novel and intuitive mutation operators that navigate large search spaces; we stress that no human participation is required once evolution starts and that the output is a fully-trained model. Throughout this work, we place special emphasis on the repeatability of results, the variability in the outcomes and the computational requirements.
Neutrino properties from high energy astrophysical neutrinos

It is shown how high-energy neutrino beams from very distant sources can be utilized to learn about some properties of neutrinos such as lifetimes. Furthermore, even mixing elements such as U{sub e3} and the CP-violating phase in the neutrino mixing matrix can be measured in principle. Pseudo-Dirac mass differences as small as 10{sup -18} eV{sup 2} can be probed as well.
Tax Compliance and Enforcement

This paper reviews recent economic research in tax compliance and enforcement. After briefly laying out the economics of tax evasion, it focuses on recent empirical contributions. It first discusses what methodologies and data have facilitated these contributions, and then presents critical summaries of what has been learned. It discusses a promising new development—the analysis of randomized controlled trials mostly delivered via letters from the tax authority—and then reviews recent research using various methods about the impact of the principal enforcement tax policy instruments: audits, information reporting, and remittance regimes. I also explore several understudied issues worthy of more research attention. The paper closes by outlining a normative framework based on the behavioral response elasticities now being credibly estimated that allow one to assess whether a given enforcement intervention is worth doing.
A microlens array on curved substrates by 3D micro projection and reflow process

Abstract Microlens arrays are becoming increasingly important because of their widespread applications in optical, electronic, and energy fields. Currently, microlens array fabrication processes are mainly developed on planar substrates. For nonplanar substrates, existing fabrication methods suffer from various disadvantages. This is largely due to the inherent technical complexity associated with 3D microstructure fabrication processes. In this study, an innovative 3D fabrication method for microlens arrays on curved surfaces is introduced. To fabricate the microlens array, a polymethylmethacrylate microlens array on a curved surface was used as projection optics. A thick layer of positive photoresist SPR 220 was spin coated on a curved, titanium-coated aluminum substrate. A pre-selected pattern was projected onto the photoresist by using a home built exposure system. The development process resulted in micro cylinders on the curved substrate. A thermal reflow process was then performed on the cylinder array to form the microlens array. Experiments were conducted to evaluate the factors that affect the shapes of the microlenses. These factors include film thickness variation, exposure and development variation, slope of the substrate, height to width ratio and heating time in thermal reflow process. Finally microlenses were tested using a Twyman–Green interferometer. Results showed that the required shape of the microlenses achieved by controlling the process parameters.
Discrete element modeling of powder flow and laser heating in direct metal laser sintering process

Abstract A novel particle-based discrete element model (DEM) is developed to simulate the whole Direct Metal Laser Sintering (DMLS) process, which includes simplified powder deposition, recoating, laser heating, and holding stages. This model is first validated through the simulation of particle flow and heat conduction in the powder bed, and the simulated results are in good agreement with either experiment in the literature or finite element method. Then the validated model is employed to the DMLS process. The effects of laser power, laser scan speed, and hatch spacing on the temperature distributions in the powder bed are investigated. The results demonstrate that the powder bed temperature rises as the laser power is increased. Increasing laser scan speed and laser hatch spacing will not affect the average temperature increase in the powder bed since energy input is kept same. However, a large hatch spacing may cause non-uniform temperature distribution and microstructure inhomogeneity. The model developed in this study can be used as a design and optimization tool for DMLS process.
On the L^1 norm of an exponential sum involving the divisor function

In this paper, we obtain bounds on the $$L^1$$ -norm of the sum $$\sum _{n\le x}\tau (n)e(\alpha n)$$ where $$\tau (n)$$ is the divisor function.
Communication Requirements and Informative Signaling in Matching Markets

We study how much communication is needed to find a stable matching in a two-sided matching market with private preferences. Segal (2007) and Gonczarowski et al.~(2015) showed that in the worst case, any protocol that computes a stable matching requires the communication cost per agent to scale linearly in the total number of agents. In real-world markets with many agents, this communication requirement is implausibly high. This casts doubts on whether stable matching can arise in large markets. We study markets with realistic structure on the preferences and information of agents, and show that in "typical" markets, a stable matching can be found with much less communication effort. In our model, the preferences of workers are unrestricted, and the preferences of firms follow an additively separable latent utility model. Our efficient communication protocol modifies workers-proposing DA, by having firms signal workers they especially like, while also broadcasting qualification requirements to discourage other workers who have no realistic chances from applying. In the special case of tiered random markets, the protocol can be modified to run in two-rounds and involve only private messages. Our protocols have good incentive properties and give insights on how to mediate large matching markets to reduce congestion.
Revisiting the Nyström method for improved large-scale machine learning

We reconsider randomized algorithms for the low-rank approximation of symmetric positive semi-definite (SPSD) matrices such as Laplacian and kernel matrices that arise in data analysis and machine learning applications. Our main results consist of an empirical evaluation of the performance quality and running time of sampling and projection methods on a diverse suite of SPSD matrices. Our results highlight complementary aspects of sampling versus projection methods; they characterize the effects of common data preprocessing steps on the performance of these algorithms; and they point to important differences between uniform sampling and nonuniform sampling methods based on leverage scores. In addition, our empirical results illustrate that existing theory is so weak that it does not provide even a qualitative guide to practice. Thus, we complement our empirical results with a suite of worst-case theoretical bounds for both random sampling and random projection methods. These bounds are qualitatively superior to existing bounds--e.g., improved additive-error bounds for spectral and Frobenius norm error and relative-error bounds for trace norm error--and they point to future directions to make these algorithms useful in even larger-scale machine learning applications.
Arrangement Increasing Resource Allocation

Consider a system composed of several units. The performance of each unit can be affected by providing a portion of a limited amount of costly resources available. An allocation of resources to a unit results in a unit’s response that depends on the level of resources allocated to it and some of its random parameters. In this paper we consider cases where each unit has one or two random parameters. The overall performance of the system is mapped by a function on the vector of responses generated by all the units in the system. Our interest is in identifying the conditions on the response function of the units, the system performance function and the random parameters under which the random system performance as a function of the resource allocation has stochastic arrangement increasing property. This allows one to substantially reduce the number of allocation that needs to be searched to identify an optimal allocation that maximizes the expected utility derived from the system response as a result of the resource allocation.
Designing the competition: A future of roles beyond lawyers? The case of the USA

Most of the civil justice problems Americans experience never receive service from an attorney. Indeed, daily around the country, thousands of people arrive at court not only without a lawyer to represent them, but also without an understanding of where to go, what to do, or what will happen while they are there. Many jurisdictions are experimenting with models for assisting unrepresented people through the use of “roles beyond lawyers,” roles staffed by people who are not fully qualified attorneys but perform some of the tasks traditionally performed only by attorneys. One interesting aspect of these developments is their source: courts and bar associations, stewards of the jurisdictional core of the legal profession, are in a sense designing their own competition as they create these new roles that nibble at the U.S. legal profession’s strong monopoly on both representation and legal advice. This project creates frameworks for evaluating the functioning and impacts of these emerging programs, with a particular focus on their potential to contribute to solving the contemporary crisis in access to justice, sometimes termed the “justice gap.” One framework identifies elements on which any such program should be evaluated, focusing on the key challenges of appropriateness, efficacy, and sustainability. The other framework identifies key choice points in program design that are likely to affect programs’ success at meeting the three key challenges.
On-the-job training : returns, barriers to provision, and policy implications

Firms that provide on-the-job training do so when it is critical to their productivity -- and when productivity is critical to their survival. This paper begins by confirming a significant and positive return from on-the-job training on wages and productivity, as well as the presence of positive externalities from on-the-job training, while discussing the methodological considerations at play. The paper then reviews and validates the presence of market failures such as information asymmetries within the firm as a result of low-quality management practices that dampen firm demand for on-the-job training. Lack of competition in the firm’s external environment appears to undermine adoption of on-the-job training and other complementary productivity-enhancing activities within the firm. The literature suggests that for most firms, a comprehensive policy approach that resolves external constraints to becoming more productive is likely to have a positive impact on the provision of on-the-job training and adoption of complementary policies. More direct forms of firm-level support to improve management capabilities could also alleviate under-provision of on-the-job training. Where societies have improved welfare as a goal, public policy measures would be needed to complement on-the-job training for some specific groups of workers (older, less educated, women). In essence, the paper highlights the importance of demand-side constraints for firms, rather than supply-side constraints, for the provision of on-the-job training.
Mental Set and Complexity Effects in the Diagnosis of Simultaneous Faults in a Simple Binary Adder

Abstract This paper focuses on the challenge to human diagnostic reasoning posed by multiple faults. Two sources of difficulty were tested; mental set and multiple fault complexity. Mental set was manipulated by training subjects on single or multiple faults and then transferring them to multiple fault diagnosis. Half the subjects were transferred to a multiple fault with simple easily separable symptoms and the other half to one with more complex highly interactive symptoms. Results suggest that mental set and multiple fault complexity affect the correctness, latency and subjective workload of transfer multiple fault diagnosis, but not the number or range of tests made before the final diagnosis. Inability to diagnose the transfer multiple fault was wholly due to (1) failure to explore the symptom space so as to see the sufficient and necessary evidence to diagnose the multiple fault (2) failure to consider the possibility of multiple faults, or (3) both.
The Integration of Economic History into Economics

In the USA today the academic field of economic history is much closer to economics than it is to history in terms of professional behavior, a stylized fact that I call the “integration of economic history into economics.” I document this using two types of evidence—use of econometric language in articles appearing in academic journals of economic history and economics; and publication histories of successive cohorts of Ph.D.s in the first decade since receiving the doctorate. Over time, economic history became more like economics in its use of econometrics and in the likelihood of scholars publishing in economics, as opposed to, say, economic history journals. But the pace of change was slower in economic history than in labor economics, another subfield of economics that underwent profound intellectual change in the 1950s and 1960s, and there was also a structural break evident for post-2000 Ph.D. cohorts. To account for these features of the data, I sketch a simple, overlapping generations model of the academic labor market in which junior scholars have to convince senior scholars of the merits of their work in order to gain tenure. I argue that the early cliometricians—most notably, Robert Fogel and Douglass North—conceived of a scholarly identity for economic history that kept the field distinct from economics proper in various ways, until after 2000 when their influence had waned.
Congenital Polyps of the Posterior Urethra in Neonates

Three neonates with congenital polyps of the posterior urethra are reported. Antenatal ultrasound detection of urinary tract dilatation should result in an increased proportion of these lesions being diagnosed in the neonatal period.
Evaluation of Urine Culture Screening by Light-Scatter Photometry

Urine screening for bacteriuria by light-scatter photometry (Autobac) was evaluated for accuracy and compared with a colony count by the calibrated loop method. Incubation time, inoculum size, precision, and interference of particulate matter were evaluated in an effort to standardize the screening procedure. Results showed that urines could be accurately screened for Enterobacteriaceae by inoculating a single Autobac cuvette chamber with 0.1 or 0.2 ml of urine and determining the voltage change after four hours. A change of greater than or equal to 0.2 units indicates significant bacteriuria. Decreased accuracy was noted for urines having greater than 10(5) cfu/ml of Pseudomonas species or gram-positive cocci, possibly because these organisms grow more slowly.
Pathology of the Testis in Acquired Immunodeficiency Syndrome

The acquired immunodeficiency syndrome (AIDS) is most often a sexually transmitted disease acquired via male genital tract secretions. We performed a retrospective controlled study of testicular tissue taken from 100 AIDS patients at autopsy to determine the nature and spectrum of macroscopic and microscopic changes associated with AIDS in the testis. The AIDS patients showed a highly significant constellation of findings that included lymphocytic infiltration, perivasculitis, germ-cell loss, interstitial fibrosis, decreased mean tubular diameter and increased mean tubular wall thickness. Only four cases showed evidence of testicular involvement with opportunistic infectious agents. In 48 cases gross pathological findings were present. Only four cases had histologically normal testes. We conclude that AIDS should be part of the differential diagnosis of testicular atrophy.
Enhancement or Inhibition of Tumor Growth by interferon: Dependence on Treatment Protocol

MSC cells are tumor cells originally induced in BALB/c mice by Moloney sarcoma virus. In these studies we demonstrated that, although these tumor cells are sensitive in vitro both to lysis by NK or NK-like cells and to the growth-inhibitory effect of murine L-cell interferon (IFN), the growth of the tumor in vivo could be either inhibited or enhanced by IFN. The outcome of in vivo IFN treatment was dependent on the timing and route of IFN administration relative to tumor challenge. IFN given systematically at the same time as tumor challenge resulted in enhancement of primary tumor formation, rate of tumor growth and subsequent progressive tumor growth. In contrast, IFN administered at the site of tumor inoculation on days 1-3 after tumor challenge inhibited tumor formation and growth. Histopathology of tissue sections obtained from the site of tumor challenge confirmed these results. Similar studies performed in mice given 450 rads of X-irradiation showed that IFN could still inhibit tumor growth when administered at the site of tumor inoculation on days 1-3 after tumor challenge. IFN administered simultaneously with tumor challenge, however, did not enhance tumor growth in irradiated mice. These results are consistent with the interpretation that 1) inhibition of MSC-induced tumor growth by IFN has a radioresistant component and 2) the enhancement of MSC-induced tumor formation by IFN is dependent on interaction with a radiosensitive population of cells, possibly lymphoid cells.
Reminders of past choices bias decisions for reward in humans

We provide evidence that decisions are made by consulting memories for individual past experiences, and that this process can be biased in favour of past choices using incidental reminders. First, in a standard rewarded choice task, we show that a model that estimates value at decision-time using individual samples of past outcomes fits choices and decision-related neural activity better than a canonical incremental learning model. In a second experiment, we bias this sampling process by incidentally reminding participants of individual past decisions. The next decision after a reminder shows a strong influence of the action taken and value received on the reminded trial. These results provide new empirical support for a decision architecture that relies on samples of individual past choice episodes rather than incrementally averaged rewards in evaluating options and has suggestive implications for the underlying cognitive and neural mechanisms.