cssi/SciSciGPT-SciSciNet huggingface dataset:
Hybrid optical antenna with high directivity gain

Coupling between electronic state and far field light, including absorption and spontaneous emission, is a central issue for applications such as quantum metrology, optical quantum information, single molecule fluorescence spectroscopy, and ultra sensitive detection which demand on high quantum efficiency. In such applications, propagating far field light with diffraction limited spatial distribution has to be coupled to the electronic state of a quantum absorber/emitter with a size far below the diffraction limit. Such a significant contrast between the wavelengths of photon and electron sets limitations on the light-matter interaction strength. The most straight forward solution is to convert far-field modes to near-field modes with dimensional scale closer to the electronic state. The process of converting far field to near field and vice versa can be conducted by an antenna as an intermediate element between far field mode and electronic state in a quantum element (absorber/emitter). Here, we classify optical antenna based on their performance into three categories. Considering each category advantage, we propose a hybrid antenna with superior performance. A quantum efficiency of about 50% is predicted for a semiconductor with volume of ~λ3/170. Despite the weak optical absorption coefficient of 2000 cm -1 in the long infrared wavelength of ~8 μm, very strong far-filed coupling has been achieved, as evidenced by an axial directivity gain of 16 dB, which is only 3 dB bellow of theoretical limit.
Chromatin organization changes during the establishment and maintenance of the postmitotic state

Genome organization changes during development as cells differentiate. Chromatin motion becomes increasingly constrained and heterochromatin clusters as cells become restricted in their developmental potential. These changes coincide with slowing of the cell cycle, which can also influence chromatin organization and dynamics. Terminal differentiation is often coupled with permanent exit from the cell cycle, and existing data suggest a close relationship between a repressive chromatin structure and silencing of the cell cycle in postmitotic cells. Heterochromatin clustering could also contribute to stable gene repression to maintain terminal differentiation or cell cycle exit, but whether clustering is initiated by differentiation, cell cycle changes, or both is unclear. Here we examine the relationship between chromatin organization, terminal differentiation and cell cycle exit. We focused our studies on the Drosophila wing, where epithelial cells transition from active proliferation to a postmitotic state in a temporally controlled manner. We find there are two stages of G0 in this tissue, a flexible G0 period where cells can be induced to reenter the cell cycle under specific genetic manipulations and a state we call “robust,” where cells become strongly refractory to cell cycle reentry. Compromising the flexible G0 by driving ectopic expression of cell cycle activators causes a global disruption of the clustering of heterochromatin-associated histone modifications such as H3K27 trimethylation and H3K9 trimethylation, as well as their associated repressors, Polycomb and heterochromatin protein 1 (HP1). However, this disruption is reversible. When cells enter a robust G0 state, even in the presence of ectopic cell cycle activity, clustering of heterochromatin-associated modifications is restored. If cell cycle exit is bypassed, cells in the wing continue to terminally differentiate, but heterochromatin clustering is severely disrupted. Heterochromatin-dependent gene silencing does not appear to be required for cell cycle exit, as compromising the H3K27 methyltransferase Enhancer of zeste, and/or HP1 cannot prevent the robust cell cycle exit, even in the face of normally oncogenic cell cycle activities. Heterochromatin clustering during terminal differentiation is a consequence of cell cycle exit, rather than differentiation. Compromising heterochromatin-dependent gene silencing does not disrupt cell cycle exit.
Spectroscopic Investigations of Dithienyl Polyenes

To understand the properties of light-sensitive compounds used in optical limiters having photoinduced charge transfer mechanisms, we have investigated the photophysics of a series of di(2-thienyl-3,4-butyl)polyenes. Spectroscopic measurements were obtained as a function of the number of double bonds(n = 1-8). From analysis of the bandshape of the emission spectra, we found evidence of vibronic coupling between the S1 and S2 excited states. The degree of coupling increased with solvents of high refractive index. The appearance of the cis band in absorption spectra of dithienyl polyenes having 6-8 double bonds suggested equilibria between scis and s-trans conformors. The cis band intensity increased in lower polarity solvents, implying solvent-induced conformation changes in these dyes. Trends in the data reflected the ordering, energy gap between and mixing of 1Bu* and 1Ag* excited state configurations.
How Efficient is Dynamic Competition? The Case of Price as Investment

We study industries where the price that a firm sets serves as an investment into lower cost or higher demand. We assess the welfare implications of the ensuing competition for the market using analytical and numerical approaches to compare the equilibria of a learning-by-doing model to the first-best planner solution. We show that dynamic competition leads to low deadweight loss. This cannot be attributed to similarity between the equilibria and the planner solution. Instead, we show how learning-by-doing causes the various contributions to deadweight loss to either be small or partly offset each other.
NOT ALL CEMENTLESS STEMS ARE CREATED EQUAL: IS THERE A SELECTION BIAS?

In recent years, cementless stems have dominated the North American market. There are several categories of cementless stems, but in the past 20 years, the two most popular designs in the United States have been the extensively coated cylindrical cobalt-chrome (CoCr) stem and the proximally coated tapered titanium stem, which in recent years has become the most common. The 10-year survival for both stem types has been over 95% with a distinction made on factors other than stem survival, including thigh pain, stress shielding, complications of insertion, and ease of revision. Conventional wisdom holds that proximally coated titanium stems have less stress shielding, less thigh pain, and a higher quality clinical result. Recent studies, however, including randomised clinical trials have found that the incidence of thigh pain and clinical result is essentially equivalent between the stem types, however, there is a modest advantage in terms of stress shielding for a tapered titanium stem over an extensively coated CoCr stem. One study utilizing pain drawings did establish that if a CoCr cylindrical stem was utilised, superior clinical results in terms of pain score and pain drawings were obtained with a fully coated versus a proximally coated stem. In spite of the lack of a clinically proven advantage in randomised trials, tapered titanium stems have been favored because of the occasional occurrence of substantial stress shielding, the increased clinical observation of thigh pain severe enough to warrant surgical intervention, ease of use of shorter tapered stems that involve removal of less trochanteric bone and less risk of fracture both at the trochanter and the diaphysis due to the shorter, and greater ease of insertion through more limited approaches, especially anterior approaches. When tapered stems are utilised, there may be an advantage to a more rectangular stem cross-section in patients with type C bone. In spite of the numerous clinical advantages of tapered titanium stems, there still remains a role for more extensively coated cylindrical stems in patients that have had prior surgery of the proximal femur, particularly for a hip fracture, which makes proximal fixation, ingrowth, and immediate mechanical stability difficult to assure consistently. Cement fixation should also be considered in these cases. While the marketplace and the clinical evidence strongly support routine use of tapered titanium proximally coated relatively short stems with angled rather than straight proximal lateral geometry in the vast majority of cases, there still remains a role for more extensively coated cylindrical and for specific indications.
Stochastic Spiking Neural Networks Enabled by Magnetic Tunnel Junctions: From Nontelegraphic to Telegraphic Switching Regimes

Artificial neural networks built around nanoelectronic components are a means to realizing compact, energy-efficient cognitive intelligence. The authors use the inherent device physics of nanomagnets to emulate the computational primitives of a neural network, reducing the energy and area requirements of the underlying hardware. They analyze the performance of stochastic neuromorphic computing platforms with magnets of different barrier heights, and show how the core network architecture must be modified as the magnets scale down to the superparamagnetic regime.
Dynamic choice under ambiguity

This paper analyzes dynamic choice for decision makers whose preferences violate Savage’s sure-thing principle (Savage 1954) and, therefore, give rise to violations of dynamic consistency. The consistent-planning approach introduced by Strotz (1955–1956) provides one way to deal with dynamic inconsistencies; however, consistent planning is typically interpreted as a solution concept for a game played by “multiple selves” of the same individual. The main result of this paper shows that consistent planning under uncertainty is fully characterized by suitable behavioral assumptions on the individual’s preferences over decision trees. In particular, knowledge of ex ante preferences over trees is sufficient to characterize the behavior of a consistent planner. The results thus enable a fully decision-theoretic analysis of dynamic choice with dynamically inconsistent preferences. The analysis accommodates arbitrary decision models and updating rules; in particular, no restriction needs to be imposed on risk attitudes and sensitivity to
Deep Learning Accurately Predicts Estrogen Receptor Status in Breast Cancer Metabolomics Data.

Metabolomics holds the promise as a new technology to diagnose highly heterogeneous diseases. Conventionally, metabolomics data analysis for diagnosis is done using various statistical and machine learning based classification methods. However, it remains unknown if deep neural network, a class of increasingly popular machine learning methods, is suitable to classify metabolomics data. Here we use a cohort of 271 breast cancer tissues, 204 positive estrogen receptor (ER+), and 67 negative estrogen receptor (ER−) to test the accuracies of feed-forward networks, a deep learning (DL) framework, as well as six widely used machine learning models, namely random forest (RF), support vector machines (SVM), recursive partitioning and regression trees (RPART), linear discriminant analysis (LDA), prediction analysis for microarrays (PAM), and generalized boosted models (GBM). DL framework has the highest area under the curve (AUC) of 0.93 in classifying ER+/ER– patients, compared to the other six machine learning a...
A Polynomial Identity via Differential Operators

We give a new proof of a polynomial identity involving the minors of a matrix, that originated in the study of integer torsion in a local cohomology module.
Ethical Use of Lifelogging Data for Research: Perceived Value and Privacy Concerns of Wearable Camera Users

Video data generated from wearable cameras is now available online, as the concept of “lifelogging” has been introduced to many citizens due to the spread of wearable camera equipment. Usually, these wearable cameras automatically capture images or record videos from a first-person point of view; they collect a new form of information that cannot be captured through other means. Citizen data Harvest in Motion Everywhere (CHIME) project pays close attention to the value of this new type of resource, particularly regarding the video data that cyclists record using wearable cameras over a long period of time. These contextually rich data capture community members’ infrastructure experiences and interactions with other transit modes, as well as environmental changes. If curated and made publicly accessible, there is great potential for various stakeholders, including public historians, researchers, city planners, and citizens, to use the data. However, making these videos open to the public and to researchers raises ethics issues, as the data include sensitive, location-based information that may intrude into private lives. Additionally, the videos include the accidental collection of data from secondary participants (bystanders). In this paper, we will describe the potential value of citizen-generated video data using the CHIME project example and discuss the privacy and ethical considerations related to the use of this type of data for scientific and citizen research.
Computer-Assisted Retrosynthesis Based on Molecular Similarity

We demonstrate molecular similarity to be a surprisingly effective metric for proposing and ranking one-step retrosynthetic disconnections based on analogy to precedent reactions. The developed approach mimics the retrosynthetic strategy defined implicitly by a corpus of known reactions without the need to encode any chemical knowledge. Using 40 000 reactions from the patent literature as a knowledge base, the recorded reactants are among the top 10 proposed precursors in 74.1% of 5000 test reactions, providing strong quantitative support for our methodology. Extension of the one-step strategy to multistep pathway planning is demonstrated and discussed for two exemplary drug products.
CycSAT: SAT-based attack on cyclic logic encryptions

Cyclic logic encryption is a newly proposed circuit obfuscation technique in hardware security. It was claimed to be SAT-unresolvable because feedback cycles were intentionally inserted under keys into the encryption. We show in the paper that even though feedback cycles introduce extra difficulty for an attacker, they can still be overcome with SAT-based techniques. Specifically, we propose CycSAT Algorithms based on SAT with different acyclic conditions that can efficiently decrypt cyclic encryptions. Experimental results have shown that our CycSAT is efficient and effective to decrypt cyclic encryptions, and we need to develop new encryptions with better security properties.
Transition-based versus state-based reward functions for MDPs with Value-at-Risk

In reinforcement learning, the reward function on current state and action is widely used. When the objective is about the expectation of the (discounted) total reward only, it works perfectly. However, if the objective involves the total reward distribution, the result will be wrong. This paper studies Value-at-Risk (VaR) problems in short- and long-horizon Markov decision processes (MDPs) with two reward functions, which share the same expectations. Firstly we show that with VaR objective, when the real reward function is transition-based (with respect to action and both current and next states), the simplified (state-based, with respect to action and current state only) reward function will change the VaR. Secondly, for long-horizon MDPs, we estimate the VaR function with the aid of spectral theory and the central limit theorem. Thirdly, since the estimation method is for a Markov reward process with the reward function on current state only, we present a transformation algorithm for the Markov reward process with the reward function on current and next states, in order to estimate the VaR function with an intact total reward distribution.
R-spondins can potentiate WNT signaling without LGRs

The WNT signaling pathway regulates patterning and morphogenesis during development and promotes tissue renewal and regeneration in adults. The R-spondin (RSPO) family of four secreted proteins, RSPO1-4, amplifies target cell sensitivity to WNT ligands by increasing WNT receptor levels. Leucine-rich repeat-containing G-protein coupled receptors (LGRs) 4-6 are considered obligate high-affinity receptors for RSPOs. We discovered that RSPO2 and RSPO3, but not RSPO1 or RSPO4, can potentiate WNT/β-catenin signaling in the absence of all three LGRs. By mapping the domains on RSPO3 that are necessary and sufficient for this activity, we show that the requirement for LGRs is dictated by the interaction between RSPOs and the ZNRF3/RNF43 E3 ubiquitin ligases and that LGR-independent signaling depends on heparan sulfate proteoglycans (HSPGs). We propose that RSPOs can potentiate WNT signals through distinct mechanisms that differ in their use of either LGRs or HSPGs, with implications for understanding their biological functions.
A Longitudinal Study of Equity-Oriented STEM-Rich Making Among Youth From Historically Marginalized Communities

The maker movement has evoked interest for its role in breaking down barriers to STEM learning. However, few empirical studies document how youth are supported over time in STEM-rich making projects or their outcomes. This longitudinal critical ethnographic study traces the development of 41 youth maker projects in two community-centered making programs. Building a conceptual argument for an equity-oriented culture of making, the authors discuss the ways in which making with and in community opened opportunities for youth to project their communities’ rich culture knowledge and wisdom onto their making while also troubling and negotiating the historicized injustices they experience. The authors also discuss how community engagement legitimized a practice of co-making, which supported equity-oriented goals and outcomes.
Income, environmental considerations, and sustainable energy consumption in Africa

Evidence on income as a crucial driver of renewable energy consumption in Africa is mixed. But hydropower accounts for over 90% of renewable energy in sub-Sahara Africa alone. Yet, empirical eviden...
Synaptic Release of Acetylcholine Rapidly Suppresses Cortical Activity by Recruiting Muscarinic Receptors in Layer 4

Cholinergic afferents from the basal forebrain (BF) can influence cortical activity on rapid time scales, enabling sensory information processing and exploratory behavior. However, our understanding of how synaptically released acetylcholine (ACh) influences cellular targets in distinct cortical layers remains incomplete. Previous studies have shown that rapid changes in cortical dynamics induced by phasic BF activity can be mediated by the activation of nicotinic ACh receptors (nAChRs) expressed in distinct types of GABAergic interneurons. In contrast, muscarinic ACh receptors (mAChRs) are assumed to be involved in slower and more diffuse ACh signaling following sustained increases in afferent activity. Here, we examined the mechanisms underlying fast cholinergic control of cortical circuit dynamics by pairing optical stimulation of cholinergic afferents with evoked activity in somatosensory cortical slices of mice of either sex. ACh release evoked by single stimuli led to a rapid and persistent suppression of cortical activity, mediated by mAChRs expressed in layer 4 and to a lesser extent, by nAChRs in layers 1-3. In agreement, we found that cholinergic inputs to layer 4 evoked short-latency and long-lasting mAChR-dependent inhibition of the large majority of excitatory neurons, whereas inputs to layers 1-3 primarily evoked nAChR-dependent excitation of different classes of interneurons. Our results indicate that the rapid cholinergic control of cortical network dynamics is mediated by both nAChRs and mAChRs-dependent mechanisms, which are expressed in distinct cortical layers and cell types.SIGNIFICANCE STATEMENT Acetylcholine (ACh) release from basal forebrain (BF) afferents to cortex influences a variety of cognitive functions including attention, sensory processing, and learning. Cholinergic control occurs on the time scale of seconds and is mediated by BF neurons that generate action potentials at low rates, indicating that ACh acts as a point-to-point neurotransmitter. Our findings highlight that even brief activation of cholinergic afferents can recruit both nicotinic and muscarinic ACh receptors expressed in several cell types, leading to modulation of cortical activity on distinct time scales. Furthermore, they indicate that the initial stages of cortical sensory processing are under direct cholinergic control.
Three-dimensional gadolinium-enhanced MR angiography for aortoiliac inflow assessment plus renal artery screening in a single breath hold

PURPOSE: To develop a magnetic resonance (MR) angiography protocol, with use of breath-hold techniques, for simultaneous aortoiliac inflow assessment and renal artery screening in patients with lower extremity ischemia or aortic aneurysm. MATERIALS AND METHODS: Breath-hold three dimensional gadolinium-enhanced MR angiography was performed in 50 patients (conventional arteriography in 47 was the standard of reference). After multiple strategies were tested in the first 18 patients, a final protocol was formulated and tested in the subsequent 32 patients. RESULTS: The final protocol comprised a single-slab (28 3-mm-thick partitions) coronal acquisition (repetition time, 7 msec; echo time, 2.8 msec; flip angle, 60 degrees) during a single breath hold, enhanced with 30 mL gadoteridol. In the final 32 patients, sensitivity and specificity, respectively, for obstructive lesions were 100% and 100% for the aorta, 100% and 98% for common iliac arteries, 100% and 89% for external iliac arteries, 100% and 89% for ma...
How Busyness Influences SEC Compliance Activities: Evidence from the Filing Review Process and Comment Letters

The SEC reviews firm filings and issues comment letters on those filings. These comment letters play an important role in the assessment of firm value. These activities are seasonally compressed because over 70 percent of registrants have a December fiscal year‐end. Research in other settings finds that busyness leads to negative outcomes. We examine how busyness impacts the frequency, scope, and timeliness of comment letters. We find that the SEC issues fewer comment letters when busy, focuses its limited resources on the most severe cases of disclosure noncompliance, and extends the amount of time between receiving a firm's filing and issuing a comment letter. Despite this, we find no evidence that the SEC misses more serious compliance issues when busy. Our results have implications for policymakers responsible for allocating resources to the SEC. En quoi l'affairement influe sur les activites de la SEC visant le respect des obligations en matiere de conformite : donnees tirees du processus d'examen des declarations et des lettres de commentaires La SEC procede a l'examen des declarations des societes et publie des lettres de commentaires sur ces declarations. Ces lettres de commentaires jouent un role important dans l'estimation de la valeur d'une entreprise. L'intensite de ces activites de la SEC varie selon la saison, compte tenu du fait que l'exercice de plus de 70 pour cent des societes inscrites se termine en decembre. Des recherches menees dans d'autres contextes indiquent que l'affairement conduit a des resultats negatifs. Les auteures se demandent en quoi l'affairement influe sur la frequence, la portee et la rapidite de publication des lettres de commentaires. Elles constatent que la SEC, lorsqu'elle se trouve en periode d'effervescence, publie moins de lettres de commentaires, concentre les ressources limitees dont elle dispose sur les cas les plus graves de non‐conformite des declarations et allonge le delai qui s'ecoule entre la reception de la declaration d'une societe et la publication de la lettre de commentaires. En depit de ces observations, les auteures ne relevent aucune donnee qui demontrerait que la SEC omet des problemes de conformite plus serieux lorsqu'elle est affairee. Ces resultats interesseront les responsables de l'elaboration des politiques charges de l'affectation des ressources a la SEC.
Chlamydia muridarum Genital and Gastrointestinal Infection Tropism Is Mediated by Distinct Chromosomal Factors

Some members of the genus Chlamydia, including the human pathogen Chlamydia trachomatis, infect multiple tissues, including the genital and gastrointestinal (GI) tracts. However, it is unknown if bacterial targeting to these sites is mediated by multifunctional or distinct chlamydial factors. We previously showed that disruption of individual large clostridial toxin homologs encoded within the Chlamydia muridarum plasticity zone were not critical for murine genital tract infection. Here, we assessed whether cytotoxin genes contribute to C. muridarum GI tropism. Infectivity and shedding of wild-type (WT) C. muridarum and three mutants containing nonsense mutations in different cytotoxin genes, tc0437, tc0438, and tc0439, were compared in mouse genital and GI infection models. One mutant, which had a nonsense mutation in tc0439, was highly attenuated for GI infection and had a GI 50% infectious dose (ID50) that was 1,000 times greater than that of the WT. GI inoculation with this mutant failed to elicit anti-chlamydial antibodies or to protect against subsequent genital tract infection. Genome sequencing of the tc0439 mutant revealed additional chromosomal mutations, and phenotyping of additional mutants suggested that the GI attenuation might be linked to a nonsense mutation in tc0600 The molecular mechanism underlying this dramatic difference in tissue-tropic virulence is not fully understood. However, isolation of these mutants demonstrates that distinct chlamydial chromosomal factors mediate chlamydial tissue tropism and provides a basis for vaccine initiatives to isolate chlamydia strains that are attenuated for genital infection but retain the ability to colonize the GI tract and elicit protective immune responses.
Measuring and explaining patterns of Spatial Income Inequality from Outer Space : Evidence from Africa

This paper argues for night--lights data as an alternative data source for measuring spatial inequalities in Africa, where the paucity of subnational income data is persistent. The analysis compares the statistical relationships between income and lights-based measures of spatial income inequality in South Africa and shows that night-lights are a decent proxy for spatial income inequality. Further analysis of the patterns of lights-based spatial income inequality across 48 countries in Africa broadly reveals rising patterns between 1992 and 2013. Following the climate-economy literature, the analysis also reveals that temperature and precipitation changes significantly increased spatial inequality in the long-run and the effects penetrated through income and agriculture channels across countries in the continent. These findings provide important lessons for policy discussions about how to measure, explain the patterns of, and mitigate the potential drivers of spatial inequality in Africa.
A forward branching phase space generator for hadron colliders

In this paper we develop a projective phase space generator appropriate for hadron collider geometry. The generator integrates over bremsstrahlung events which project back to a single, fixed Born event. The projection is dictated by the experimental jet algorithm allowing for the forward branching phase space generator to integrate out the jet masses and initial state radiation. When integrating over the virtual and bremsstrahlung amplitudes this results in a single K-factor, assigning an event probability to each Born event. This K-factor is calculable as a perturbative expansion in the strong coupling constant. One can build observables from the Born kinematics, giving identical results to traditional observables as long as the observable does not depend on the infrared sensitive jet mass or initial state radiation.
Impedance Eduction for Multisegment Liners

This paper explores the validity of an indirect method for impedance eduction of multisegment liners. This is accomplished via results obtained with two uniform liners and one two-segment liner, where each segment is constructed to match the geometry of one of the uniform liners. Each uniform liner is evaluated using direct and indirect impedance eduction methods. An indirect impedance eduction method is used to educe the impedance for each segment of the two-segment liner, and the results are compared with those educed for the uniform liners. These impedance spectra are shown to compare favorably for the majority of test conditions. Poorer comparisons are achieved for those test conditions where one segment of the two-segment liner provides little attenuation. Poor attenuation is a wellknown cause for impedance eduction difficulties. Overall, this multisegment impedance eduction method offers the potential to study complicated liners in a more efficient manner (i.e., without the requirement to build and test separate liners to duplicate each unique segment of the multisegment liner). More detailed studies are required to further validate this tool, and are intended to be the focus of future research.
Regulation of health care in the United States: complexity, confrontation and compromise

The United States has the largest health care system in the world, and the regulatory apparatus that oversees it is commensurately large and complicated. Considerable complexity is engendered by the federalist structure of American government, which divides powers between the federal government and the states. Additional complexity is added by private oversight, including self-regulation of important aspects of the system. This web of regulatory authority creates the opportunity for competition and confrontation between different kinds of regulators, as reflected in the regulatory structure governing four key sectors. Physicians are regulated through state licensing laws, but the profession retains considerable influence over that process as well as other aspects of education and practice. Hospital regulation is dominated by a private organization controlled by the industry. Health insurance is primarily regulated by the states. Drugs and devices are primarily regulated by the federal government. Despite this subtext of complexity and competition, the system can be seen as one of symbiosis in which the public and private sectors join in an implicit collaboration that has enabled the American health care system to grow and thrive.
In-vivo nucleus pulposus-specific regulation of adult murine intervertebral disc degeneration via wnt/beta-catenin signaling

B-Catenin, transcription factor of Wnt signaling, is promoted in patients with intervertebral disc (IVD) degeneration, but Wnt signaling decreases with aging. We hypothesize that IVD degeneration is associated with decreased Wnt signaling despite more b-Catenin. Chronic compression of tail IVDs of young-adult and aged Wnt-reporter (TOPGAL) animals initiated an age-related cascade of degenerative-like changes, which included reduced Wnt ligand expression and Wnt signaling in nucleus pulposus cells, despite elevation of b-Catenin protein and gene expression. To determine the effect of upregulated and downregulated Wnt signaling in adult discs, b-Catenin in the nucleus pulposus was stabilized (Shh-CreErT2/b-Cateninfl(Ex3)/fl(Ex3), cACT) or knocked out (Shh-CreErT2/b-Cateninfl/fl, cKO). cACT discs had promoted expression of Wnt-targets and -ligands, brachyury, extracellular matrix production and 34% greater compressive stiffness than WT (b-Cateninfl(Ex3)/fl(Ex3)) discs, but 50% less tensile stiffness. By contrast, knockout reversed the cACT phenotype: less protein expression of b-catenin in the nucleus pulposus, less expression of brachyury, heightened expression of extracellular matrix breakdown and 46% less compressive stiffness than wild-type (b-Cateninfl/fl,WT) discs. These data suggest that intervertebral disc degeneration is associated with loss of Wnt signaling and that the concomitant increase in b-catenin is a regenerative response, potentially offering a therapeutic approach to degeneration.
SwitchOut: an Efficient Data Augmentation Algorithm for Neural Machine Translation

In this work, we examine methods for data augmentation for text-based tasks such as neural machine translation (NMT). We formulate the design of a data augmentation policy with desirable properties as an optimization problem, and derive a generic analytic solution. This solution not only subsumes some existing augmentation schemes, but also leads to an extremely simple data augmentation strategy for NMT: randomly replacing words in both the source sentence and the target sentence with other random words from their corresponding vocabularies. We name this method SwitchOut. Experiments on three translation datasets of different scales show that SwitchOut yields consistent improvements of about 0.5 BLEU, achieving better or comparable performances to strong alternatives such as word dropout (Sennrich et al., 2016a). Code to implement this method is included in the appendix.
Electronic Structure Origins of Surface-Dependent Growth in III–V Quantum Dots

Indium phosphide quantum dots (QDs) have emerged as a promising candidate to replace more toxic II–VI CdSe QDs, but production of high-quality III–V InP QDs with targeted properties requires a bett...
Dual Faceted Linearization of Nonlinear Dynamical Systems Based on Physical Modeling Theory

NSF, Science and Technology Center - STC & Emergent Behaviors in Integrated Cellular Systems -EBICS (Grant CBET-0939511)
Compression flow modeling of underfill encapsulants for low cost flip chip assembly

Flip-chip technology represents a rapidly advancing area in commercial electronics. Flip-chip on board (FCOB) technology also called direct chip attach (DCA) involves the direct interconnection of integrated circuits to low cost organic substrates. In order to ensure adequate reliability, these flip-chip assemblies undergo an underfill encapsulation process in which a polymer material is placed between the chip and the substrate. Conventional underfill processing is achieved through chip site to chip site dispensing and underfill flow via capillary action, making it a costly and time consuming process particularly as device sizes increase and standoff gaps decrease. Extensive cost modeling of conventional flip-chip process technology has shown underfill processing, cleaning, and electroplating solder bumps and substrates to be the major cost driving factors. As part of the Low Cost Next Generation Flip-Chip Processing Program, an advanced flip-chip assembly process is being developed. This process eliminates the need for time consuming capillary flow processing using a compression flow technique where the underfill is applied prior to chip placement. The innovative process integrates the chip placement and polymer underfill processes using a compression or squeeze flow technique. It results in significantly lower assembly costs and reduced cycle time. In general, the compression flow of the underfill material governs assembly yield and reliability. This paper focuses on flow simulation studies of the compression flow chip placement process. It represents a fundamental advancement in compression flow simulation of polymers in its successful application to the complex geometries and surface topologies demanded by miniaturized flip-chip assembly. Here a simulation methodology is developed and simulation studies are conducted to characterize the compression flow of the underfill, estimate required chip placement forces, evaluate the effect of underfill geometry, and assess the potential formation of voids. Results yield design guidelines that give insight into process parameters such as the limits on underfill deposition geometry and underfill viscosity, and provided an initial process window.
Buccal versus Vaginal Misoprostol for Term Induction of Labor: A Retrospective Cohort Study.

Objective To compare the efficacy of similar buccal and vaginal misoprostol doses for induction of labor. Study Design Retrospective chart review of 207 consecutive women undergoing term induction of labor with misoprostol. Misoprostol route and dosing were collected. Time to delivery and other labor outcomes (e.g., vaginal delivery less than 24 hours) were compared between women receiving buccal and vaginal misoprostol. Results There was no significant difference in time to delivery for women receiving buccal (median 18.2 hour, 95% confidence interval [CI] = [14.9, 21.5]) versus vaginal (median 18.3 hour, 95% CI = [15.0, 20.4]) misoprostol (p = 0.428); even after adjusting for covariates (p = 0.381). Women who presented with premature rupture of membranes were more likely to receive buccal misoprostol (92.7% received buccal vs. 7.3% received vaginal, p Conclusion We found no significant differences in time to delivery or other labor outcomes between buccal or vaginal dosing of misoprostol in women undergoing labor induction at term.
Causal Modeling for Cybersecurity

Causal modeling is very useful in the pursuit of cybersecurity since it often helps us to execute actions leading to fruitful results, without performing unnecessary computations that might affect the values of other variables. The causative factors that are necessary and sufficient, are explored, with the help of modeling a real-life example taken from 2017, United States cybersecurity case. One can recommend future company policies, based on the causal modeling results. It also makes us understand how an event such as a breach of cybersecurity occurs, and how it can be dealt with.
Risk factor and high-risk place variations across different robbery targets in Denver, Colorado

Abstract Purpose Risk Terrain Modeling (RTM) has been effectively used to spatially diagnose risk for crimes such as robbery, aggravated assault , and gun violence. An important contribution is to consider how risk differs across individual crimes and different target types. This study tests four different robbery target types in unique models to examine the potential for variation across significant risk factors and high-risk locations. Methods Using the online diagnostic software RTMDx, individual robbery models were run for four robbery target types in Denver, Colorado: commercial (businesses), carjacking (driver/vehicle), residential (home/dwelling), and street (pedestrians). A conjunctive analysis of case configurations was also conducted to determine the potential for spatial differences in high-risk places across target types. Results The results indicate that there is variation across risk factors, and observable differences in risk factor spatial influence, operationalization and relative risk values in each target model. Convenience stores were the only risk factor significantly associated with every target type and the conjunctive analysis matrix found that very few places were high-risk for all four robbery types. Conclusions The findings suggest different target types should be analyzed individually and interventions should focus on different high-risk locations and be tailored to specific target types.
Optimal allocations for sample average approximation

We consider a single stage stochastic program without recourse with a strictly convex loss function. We assume a compact decision space and grid it with a finite set of points. In addition, we assume that the decision maker can generate samples of the stochastic variable independently at each grid point and form a sample average approximation (SAA) of the stochastic program. Our objective in this paper is to characterize an asymptotically optimal linear sample allocation rule, given a fixed sampling budget, which maximizes the decay rate of probability of making false decision.
Geometric Invariants for Sparse Unknown View Tomography

In this paper, we study a 2D tomography problem for point source models with random unknown view angles. Rather than recovering the projection angles, we reconstruct the model through a set of rotation-invariant features that are estimated from the projection data. For a point source model, we show that these features reveal geometric information about the model such as the radial and pairwise distances. This establishes a connection between unknown view tomography and unassigned distance geometry problem (uDGP). We propose new methods to extract the distances and approximate the pairwise distance distribution of the underlying points. We then use the recovered distribution to estimate the locations of the points through constrained non-convex optimization. Our simulation results show that our point source reconstruction pipeline is robust to noise and outperforms the regularized expectation maximization (EM) baseline.
Efficient Conditional Reliability Updating with Sequential Importance Sampling

Data on the performance of engineering systems can and should be used to learn system parameters and update the system reliability estimate. This can be achieved in a Bayesian framework. In order to capture the dependence of the reliability estimate on the data used, we consider the probability of failure conditional on the updating variables, i.e. those variables on which data is available. Thus, the probability of failure becomes a random variable itself. In practice, the distribution of the conditional probability of failure may be obtained by solving a reliability problem at several samples from the updating variable space which causes a considerable increase in required computational effort. To address this challenge, we devise a procedure for the fast re-computation of failure probabilities within a sequential sampling method. We exploit the similarity of reliability problems with small distance in a suitable norm by sequentially initializing computations with failure samples of similar problem solutions.
State capacity and public choice: a critical survey

‘State capacity’ is a term associated with a popular argument in fiscal sociology, history, and political economy regarding the role of the state in the process of economic development. Much of the applied and theoretical work on state capacity already shows some influence from public choice theory, the application of the economic approach to the study of political processes. These commonalities notwithstanding, this paper argues that public choice theory can offer further insights into this literature. In particular, the public choice approach can help illuminate concepts such as those of ‘state capacity’ and ‘governance,’ which are often casually employed in the literature. It can also help us understand the interaction between state capacity and competitive pressures in the ‘market for governance’. Finally, insights from public choice can illuminate the causal nexus between investment in state capacity and economic development.
Osteochondral Allograft Transplantation: Identifying the Biomechanical Impact of Using Shorter Grafts and Pulsatile Lavage on Graft Stability.

This study seeks to identify the ability of shorter osteochondral allografts (OCAs) to resist displacement/failure. Additionally, this study seeks to evaluate the effect of pulsatile lavage (PL) on the biomechanical stability of the OCA. Fifteen-millimeter diameter, human cadaveric, OCAs of 4, 7, and 10 mm in depth were harvested for comparison of resistance to compressive and tensile loads. For each group, seven specimens were subjected to tensile loads and three specimens subjected to compressive loads until failure (pullout or subsidence). An additional study group of 10 pulsatile-lavaged OCAs of 15 mm in diameter and 7 mm in depth were introduced for comparison to the original 7 mm depth OCA group. The average tensile forces for failure for the 4, 7, and 10 mm plugs were 23.74, 199.57, and 197.69 N, respectively (p = 1.5 × 10−5). After post hoc analysis of the tensile groups, significant differences in the mean tensile force to failure were appreciated between the 4 and 7 mm groups (p = 4.12 × 10−5) and the 4 and 10 mm groups (p = 1.78 × 10−5) but not between the 7 and 10 mm groups (p = 0.9601). There were no significant differences between the average tensile forces resulting in failure for the 7 mm and 7 mm PL groups (199.57 and 205.2 N, p = 0.90) or compressive forces to failure, respectively (733.6 and 656 N, p = 0.7062). For OCAs of 15 mm in diameter, a commonly used size in practice, plugs of 7 mm in depth showed comparable resistance to pull out and subsidence as 10 mm plugs and significantly better resistance to pull out than 4 mm grafts. PL of allografts prior to insertion did not take away from the structural integrity and stability of the plug.
Is it time to get rid of earnings-per-share (EPS)?

This paper discusses recent empirical evidence showing that the presence of earnings-per-share (EPS) targets is associated with short-termist behavior. EPS targets affect stock repurchases, RD editorial decision October 29, 2018 by Editor Andrew Ellul
The Case for a Bariatric-Centered Approach to CKD Care

Not too long ago, nephrologists were mainly interested in nutrition to understand how uremic cachexia and resultant protein–calorie undernutrition influenced their patients’ wellbeing. How times have changed. As the prevalence of obesity skyrockets to over 650 million individuals worldwide, the
Human Immunodeficiency Viruses (HIV)

First page of article Keywords: human immunodeficiency viruses (HIV); viral DNA and cellular DNA
MilliSonic: Pushing the Limits of Acoustic Motion Tracking

Recent years have seen interest in device tracking and localization using acoustic signals. State-of-the-art acoustic motion tracking systems however do not achieve millimeter accuracy and require large separation between microphones and speakers, and as a result, do not meet the requirements for many VR/AR applications. Further, tracking multiple concurrent acoustic transmissions from VR devices today requires sacrificing accuracy or frame rate. We present MilliSonic, a novel system that pushes the limits of acoustic based motion tracking. Our core contribution is a novel localization algorithm that can provably achieve sub-millimeter 1D tracking accuracy in the presence of multipath, while using only a single beacon with a small 4-microphone array.Further, MilliSonic enables concurrent tracking of up to four smartphones without reducing frame rate or accuracy. Our evaluation shows that MilliSonic achieves 0.7mm median 1D accuracy and a 2.6mm median 3D accuracy for smartphones, which is 5x more accurate than state-of-the-art systems. MilliSonic enables two previously infeasible interaction applications: a) 3D tracking of VR headsets using the smartphone as a beacon and b) fine-grained 3D tracking for the Google Cardboard VR system using a small microphone array.
Radiotherapy for benign head and neck paragangliomas.

Purpose To update our experience treating benign head-and-neck paragangliomas (PGs) with radiotherapy (RT). Methods A total of 149 patients with 176 PGs received curative-intent RT; 126 received RT to 1 PG and 23 to 2 or more PGs. The most common dose fractionation schedule was 45 Gy/25 once-daily fractions/5 weeks which was used to treat 147 PGs (83.5%) in 123 patients (82.6%). Patients were followed with physical examination and CT/MRI. The median follow-up for all patients was 10.6 years (range, 0.2-50.4 years); the median follow-up for surviving patients was 11.1 years (range, 0.2-50.4). Results The 5-year, 10-year, and 15-year outcomes were: local control, 99%, 96%, and 95%; distant metastasis-free survival, 99%, 99%, and 99%; cause-specific survival, 98%, 98%, and 98%; and overall survival, 90%, 75%, and 64%, respectively. No patient developed a moderate or severe complication, or a radiation-induced second tumor or malignant transformation of the benign PG. Conclusion RT is an effective treatment for head-and-neck PGs with a low risk of complications.