cssi/SciSciGPT-SciSciNet huggingface dataset:
Conformation-Specific Infrared and Ultraviolet Spectroscopy of Cold [YAPAA+H]+ and [YGPAA+H]+ Ions: A Stereochemical “Twist” on the β-Hairpin Turn

Incorporation of the unnatural d-proline (DP) stereoisomer into a polypeptide sequence is a typical strategy to encourage formation of β-hairpin loops because natural sequences are often unstructured in solution. Using conformation-specific IR and UV spectroscopy of cold (≈10 K) gas-phase ions, we probe the inherent conformational preferences of the DP and LP diastereomers in the protonated peptide [YAPAA+H]+, where only intramolecular interactions are possible. Consistent with the solution-phase studies, one of the conformers of [YADPAA+H]+ is folded into a charge-stabilized β-hairpin turn. However, a second predominant conformer family containing two sequential γ-turns is also identified, with similar energetic stability. A single conformational isomer of the LP diastereomer, [YALPAA+H]+, is found and assigned to a structure that is not the anticipated “mirror image” β-turn. Instead, the LP stereocenter promotes a cis-alanine–proline amide bond. The assigned structures contain clues that the preference ...
Wormhole geometries in fourth-order conformal Weyl gravity

Kellie L. Ault Department of Physics, Loyola Marymount University Los Angeles, CA 90045, USA† Abstract We present an analysis of the classic wormhole geometries based on conformal Weyl gravity, rather than standard general relativity. The main characteristics of the resulting traversable wormholes remain the same as in the seminal study by Morris and Thorne, namely, that effective super-luminal motion is a viable consequence of the metric. Improving on previous work on the subject, we show that for particular choices of the shape and redshift functions the wormhole metric in the context of conformal gravity does not violate the main energy conditions at or near the wormhole throat. Some exotic matter might still be needed at the junction between our solutions and flat spacetime, but we demonstrate that the averaged null energy condition (as evaluated along radial null geodesics) is satisfied for a particular set of wormhole geometries. Therefore, if fourth-order conformal Weyl gravity is a correct extension of general relativity, traversable wormholes might become a realistic solution for interstellar travel.
Novel therapies for pancreatic adenocarcinoma.

Despite advances in our understanding of the molecular and genetic basis of pancreatic cancer, the disease remains a clinical challenge. Gemcitabine, the standard chemotherapy for pancreatic cancer, offers modest improvement of tumorrelated symptoms and marginal advantage of survival. New approaches, alone and in combination with gemcitabine, are being developed to combat this cancer. In this article we review the current status of investigations into several classes of agents: matrix metalloproteinase inhibitors; farnesyl transferase inhibitors; epidermal growth factor receptor inhibitors, including monoclonal antibodies and tyrosine kinase inhibitors; cyclooxygenase-2 inhibitors, and others. The scientific rationale, mechanism of action, and clinical trial data for these novel agents are discussed.
Learning hierarchical shape segmentation and labeling from online repositories

We propose a method for converting geometric shapes into hierarchically segmented parts with part labels. Our key idea is to train category-specific models from the scene graphs and part names that accompany 3D shapes in public repositories. These freely-available annotations represent an enormous, untapped source of information on geometry. However, because the models and corresponding scene graphs are created by a wide range of modelers with different levels of expertise, modeling tools, and objectives, these models have very inconsistent segmentations and hierarchies with sparse and noisy textual tags. Our method involves two analysis steps. First, we perform a joint optimization to simultaneously cluster and label parts in the database while also inferring a canonical tag dictionary and part hierarchy. We then use this labeled data to train a method for hierarchical segmentation and labeling of new 3D shapes. We demonstrate that our method can mine complex information, detecting hierarchies in man-made objects and their constituent parts, obtaining finer scale details than existing alternatives. We also show that, by performing domain transfer using a few supervised examples, our technique outperforms fully-supervised techniques that require hundreds of manually-labeled models.
Beyond biology: designing a new mechanism for self-replication and evolution at the nanoscale

As biology demonstrates, evolutionary algorithms are an extraordinarily powerful way to design complex nanoscale systems. While we can harness the biological apparatus for replicating and selecting DNA sequences to evolve enzymes and to some extent, organisms, we would like to build replication machinery that would allow us to evolve designs for a much wider variety of materials and systems. Here we describe work that uses techniques from the new field of structural DNA nanotechnology to modularly design nanoscale components that together can be assembled into a system for self-replicating a new form of chemical information or genome, and thus for evolving a new type of chemical sequence.
Measuring and Managing Answer Quality for Online Data-Intensive Services

Online data-intensive services parallelize query execution across distributed software components. Interactive response time is a priority, so online query executions return answers without waiting for slow running components to finish. However, data from these slow components could lead to better answers. We propose Ubora, an approach to measure the effect of slow running components on the quality of answers. Ubora randomly samples online queries and executes them twice. The first execution elides data from slow components and provides fast online answers, the second execution waits for all components to complete. Ubora uses memoization to speed up mature executions by replaying network messages exchanged between components. Our systems-level implementation works for a wide range of platforms, including Hadoop/Yarn, Apache Lucene, the Easy Rec Recommendation Engine, and the Open Ephyra question answering system. Ubora computes answer quality much faster than competing approaches that do not use memoization. With Ubora, we show that answer quality can and should be used to guide online admission control. Our adaptive controller processed 37% more queries than a competing controller guided by the rate of timeouts.
Opportunities in software engineering research for web API consumption

Nowadays, invoking third party code increasingly involves calling web services via their web APIs, as opposed to the more traditional scenario of downloading a library and invoking the library's API. However, there are also new challenges for developers calling these web APIs. In this paper, we highlight a broad set of these challenges and argue for resulting opportunities for software engineering research to support developers in consuming web APIs. We outline two specific research threads in this context: (1) web API specification curation, which enables us to know the signatures of web APIs, and (2) static analysis that is capable of extracting URLs, HTTP methods etc. of web API calls. Furthermore, we present new work on how we combine (1) and (2) to provide IDE support for application developers consuming web APIs. As web APIs are used broadly, research in supporting the consumption of web APIs offers exciting opportunities.
Cores with distinct parts and bigraded Fibonacci numbers

Abstract The notion of ( a , b ) -cores is closely related to rational ( a , b ) -Dyck paths via the bijection due to J. Anderson, and thus the number of ( a , a + 1 ) -cores is given by the Catalan number C a . Recent research shows that ( a , a + 1 ) -cores with distinct parts are enumerated by another important sequence— Fibonacci numbers F a . In this paper, we consider the abacus description of ( a , b ) -cores to introduce the natural grading and generalize this result to ( a , a s + 1 ) -cores. We also use the bijection with Dyck paths to count the number of ( 2 k − 1 , 2 k + 1 ) -cores with distinct parts. We give a second grading to Fibonacci numbers, induced by the bigraded Catalan sequence C a , b ( q , t ) .
An Overlay Architecture for Throughput Optimal Multipath Routing

Legacy networks are often designed to operate with simple single-path routing, like the shortest path, which is known to be throughput suboptimal. On the other hand, previously proposed throughput optimal policies (i.e., backpressure) require every device in the network to make dynamic routing decisions. In this paper, we study an overlay architecture for dynamic routing, such that only a subset of devices (overlay nodes) need to make the dynamic routing decisions. We determine the essential collection of nodes that must bifurcate traffic for achieving the maximum multi-commodity network throughput. We apply our optimal node placement algorithm to several graphs and the results show that a small fraction of overlay nodes is sufficient for achieving maximum throughput. Finally, we propose a threshold-based policy (BP-T) and a heuristic policy (OBP), which dynamically control traffic bifurcations at overlay nodes. Policy BP-T is proved to maximize throughput for the case when underlay paths do no overlap. In all studied simulation scenarios, OBP not only achieves full throughput but also reduces delay in comparison to the throughput optimal backpressure routing.
Characterization of Pontibacter altruii, sp. nov., isolated from a human blood culture

The genus Pontibacter is a recent addition to the family Cytophagaceae, phylum Bacteroidetes. Previous reports of its cultivation and molecular detection are from a variety of environmental sources, including marine and desert habitats. We report the first description of a Pontibacter sp., which was initially identified as Elizabethkingia meningoseptica, isolated from a human clinical specimen. On the basis of 16S rRNA gene sequence, unique mass spectral profile and phenotypic characterization, this isolate represents a novel species within the genus Pontibacter that has been named Pontibacter altruii, sp. nov., strain Grand Forks.
Learning bundled care opportunities from electronic medical records.

Abstract Objective The traditional fee-for-service approach to healthcare can lead to the management of a patient’s conditions in a siloed manner, inducing various negative consequences. It has been recognized that a bundled approach to healthcare - one that manages a collection of health conditions together - may enable greater efficacy and cost savings. However, it is not always evident which sets of conditions should be managed in a bundled manner. In this study, we investigate if a data-driven approach can automatically learn potential bundles. Methods We designed a framework to infer health condition collections (HCCs) based on the similarity of their clinical workflows, according to electronic medical record (EMR) utilization. We evaluated the framework with data from over 16,500 inpatient stays from Northwestern Memorial Hospital in Chicago, Illinois. The plausibility of the inferred HCCs for bundled care was assessed through an online survey of a panel of five experts, whose responses were analyzed via an analysis of variance (ANOVA) at a 95% confidence level. We further assessed the face validity of the HCCs using evidence in the published literature. Results The framework inferred four HCCs, indicative of (1) fetal abnormalities, (2) late pregnancies, (3) prostate problems, and (4) chronic diseases, with congestive heart failure featuring prominently. Each HCC was substantiated with evidence in the literature and was deemed plausible for bundled care by the experts at a statistically significant level. Conclusions The findings suggest that an automated EMR data-driven framework conducted can provide a basis for discovering bundled care opportunities. Still, translating such findings into actual care management will require further refinement, implementation, and evaluation.
JIGSAW-GEO (1.0): locally orthogonal staggered unstructured grid generation for general circulation modelling on the sphere

Abstract. An algorithm for the generation of non-uniform, locally orthogonal staggered unstructured spheroidal grids is described. This technique is designed to generate very high-quality staggered Voronoi–Delaunay meshes appropriate for general circulation modelling on the sphere, including applications to atmospheric simulation, ocean-modelling and numerical weather prediction. Using a recently developed Frontal-Delaunay refinement technique, a method for the construction of high-quality unstructured spheroidal Delaunay triangulations is introduced. A locally orthogonal polygonal grid, derived from the associated Voronoi diagram, is computed as the staggered dual. It is shown that use of the Frontal-Delaunay refinement technique allows for the generation of very high-quality unstructured triangulations, satisfying a priori bounds on element size and shape. Grid quality is further improved through the application of hill-climbing-type optimisation techniques. Overall, the algorithm is shown to produce grids with very high element quality and smooth grading characteristics, while imposing relatively low computational expense. A selection of uniform and non-uniform spheroidal grids appropriate for high-resolution, multi-scale general circulation modelling are presented. These grids are shown to satisfy the geometric constraints associated with contemporary unstructured C-grid-type finite-volume models, including the Model for Prediction Across Scales (MPAS-O). The use of user-defined mesh-spacing functions to generate smoothly graded, non-uniform grids for multi-resolution-type studies is discussed in detail.
Optimal Load-Side Control for Frequency Regulation in Smart Grids

Frequency control rebalances supply and demand while maintaining the network state within operational margins. It is implemented using fast ramping reserves that are expensive and wasteful, and which are expected to become increasingly necessary with the current acceleration of renewable penetration. The most promising solution to this problem is the use of demand response, i.e., load participation in frequency control. Yet it is still unclear how to efficiently integrate load participation without introducing instabilities and violating operational constraints. In this paper, we present a comprehensive load-side frequency control mechanism that can maintain the grid within operational constraints. In particular, our controllers can rebalance supply and demand after disturbances, restore the frequency to its nominal value, and preserve interarea power flows. Furthermore, our controllers are distributed (unlike the currently implemented frequency control), can allocate load updates optimally, and can maintain line flows within thermal limits. We prove that such a distributed load-side control is globally asymptotically stable and robust to unknown load parameters. We illustrate its effectiveness through simulations.
Verification of multiple agent knowledge‐based systems

This paper's purpose is extending single agent verification tests to systems with multiple agent knowledge bases. Particularly, this paper identifies potentially anomalous situations occurring between agent knowledge bases. For example, consider one agent with rule if A then B and another agent with rule if A then C, so agents have a consequence conflict for the same condition. In this setting, agents are constantly at odds, unable to reconcile differences. Alternatively, the following rules are found in one agent (if A then B, if C then A), while another agent has rule (if B then C). With two interacting rule bases, a dialogue starting with A cycles indefinitely, A → B → C → A, depending on relationships between these two agents. Additionally, with traditional problems, this paper also identifies new issues, like agent isolation property. One potential approach to identifying anomalies in multiple agent systems is comparing each subset of agents' knowledge base determining existence verification issues. Where agents' number is small this approach is feasible. However, for even medium size systems this approach explodes computationally. As a result, alternative approaches are needed. This paper finds many multiple agent verification tests are conducted on metarule set generated from all rules contained in each of agents' knowledge bases minimizing computational effort and minimizing need for new verification concepts development. A wide range of anomalies are identified for multiple agent systems. Anomalies are system properties not necessarily incorrect. An important part of system structure is anomalous knowledge. For example, multiple agent systems employ negotiations and other devices facilitating agent interaction, mitigating anomalies. However, anomalies signal a system error. Ultimately, determination to dispostion of the anomaly is likely the responsibility of the developer.
Comment on The Global Rise of Corporate Saving by Peter Chen, Loukas Karabarbounis, and Brent Neiman

The Chen, Karabarbounis and Neiman (CKN) paper provides interesting global evidence regarding the financing of corporations, and the distribution of aggregate saving between the corporate and household sectors worldwide. To execute their study on global corporate saving, the authors must map the theoretical constructs of corporate profits, investment, issuances, dividends and interest into their empirical counterparts, and, crucially, they must make decisions about what constitutes saving by corporations vs.~households. A key consideration is that, in order for it to be meaningful to distinguish corporate from household saving, and to distinguish internal vs. external financing of the corporate sector's activities, there must be some violation of the Miller and Modigliani Irrelevance Theorems regarding capital structure. That is, if the corporate sector is simply a veil, it is irrelevant whether aggregate saving resides on the balance sheet of households or corporations, and whether corporate activity is financed using internally generated funds, or by raising external finance. Thus, I begin my comment by laying out these definitional choices and highlighting where different assumptions regarding violations of the Miller and Modigliani Irrelevance Theorem (which I will call "financial frictions'') would lead to different measurement (and hence possibly different conclusions). I think this is helpful, because the authors' definition of saving, while reasonable, is very close to a measure of aggregate corporate retained earnings, or corporate net worth. While this is one measure of corporate saving, there are other, also reasonable, definitions. The most appropriate definition depends on the precise question of interest. Potential research questions include: Has the corporate sector changed how it finances total investment, internally or externally? Has the corporate sector changed the composition of investment between productive physical capital, and liquid financial assets (or "cash'')? Does whether the corporate sector retains or pays out its profits matter for the distribution of income and/or wealth? These are questions that may actually be better answered with alternative measurement schemes, as I illustrate in my comment.
Renovascular Hypertension in the Patient With Severe Atherosclerosis

• From 1976 to 1981, 22 patients were treated for atheroslcerotic renovascular disease and widespread atherosclerosis. The average age was 56 years. Preoperatively, the average blood pressure (BP) was 211/123 mm Hg. The standard operation was aortorenal bypass, associated with resection of an abdominal aortic aneurysm in three cases. Four patients had nephrectomy. Most patients were referred after failure of a previous renal revascularization procedure. In three patients, most of the renal arterial system was thrombotic. All patients had preoperative Swan-Ganz catheter placement for monitoring of fluid balance, filling pressure, and cardiac output. Intravenous vasodilators were used to control BP and to reduce the afterload on the left ventricle. There were no operative deaths. The average postoperative BP was 136/81 mm Hg. Three patients had improvement in renal function, and one was able to stop hemodialysis after operation. Because of a low mortality and overall satisfactory results, patients with atherosclerotic renovascular hypertension should be considered for vascular reconstruction. (Arch Surg1982;117:938-941)
Vitamin K-Dependent Coagulation Factors in Gram-Negative Septicemia

• Coagulation studies were performed on 16 children with gram-negative septicemia without the complications of septic shock, liver disease, malnutrition, or laboratory evidence of classic disseminated intravascular coagulation (DIC). Ten (63%) of the 16 cases were found to have abnormal partial thromboplastin and/or prothrombin times. The coagulopathy was caused by a reduction in the vitamin K—dependent coagulation factors. The mechanism that produced this coagulopathy was not known, but evidence was found that suggested that endotoxin may interfere with the vitamin K—carboxylation reaction. The data indicated that abnormal coagulation screening test results in children with gram-negative septicemia were not specific for DIC and that a significant number of patients had a coagulopathy not related to DIC. ( AJDC 1984;138:240-242)
Managing the Auditor-Client Relationship Through Partner Rotations: The Experiences of Audit Firm Partners

ABSTRACT While current audit standards explicitly state engagement partner tenure requirements, firms have flexibility in managing the rotation process. We conduct semi-structured interviews with 2...
Distribution of Singular Values of Random Band Matrices; Marchenko–Pastur Law and More

We consider the limiting spectral distribution of matrices of the form $$\frac{1}{2b_{n}+1} (R + X)(R + X)^{*}$$ , where X is an $$n\times n$$ band matrix of bandwidth $$b_{n}$$ and R is a non random band matrix of bandwidth $$b_{n}$$ . We show that the Stieltjes transform of ESD of such matrices converges to the Stieltjes transform of a non-random measure. And the limiting Stieltjes transform satisfies an integral equation. For $$R=0$$ , the integral equation yields the Stieltjes transform of the Marchenko–Pastur law.
The 16p11.2 homologs fam57ba and doc2a generate certain brain and body phenotypes

Deletion of the 16p11.2 CNV affects 25 core genes and is associated with multiple symptoms affecting brain and body, including seizures, hyperactivity, macrocephaly, and obesity. Available data suggest that most symptoms are controlled by haploinsufficiency of two or more 16p11.2 genes. To identify interacting 16p11.2 genes, we used a pairwise partial loss of function antisense screen for embryonic brain morphology, using the accessible zebrafish model. fam57ba, encoding a ceramide synthase, was identified as interacting with the doc2a gene, encoding a calcium-sensitive exocytosis regulator, a genetic interaction not previously described. Using genetic mutants, we demonstrated that doc2a+/- fam57ba+/- double heterozygotes show hyperactivity and increased seizure susceptibility relative to wild-type or single doc2a-/- or fam57ba-/- mutants. Additionally, doc2a+/- fam57ba+/- double heterozygotes demonstrate the increased body length and head size. Single doc2a+/- and fam57ba+/- heterozygotes do not show a body size increase; however, fam57ba-/- homozygous mutants show a strongly increased head size and body length, suggesting a greater contribution from fam57ba to the haploinsufficient interaction between doc2a and fam57ba. The doc2a+/- fam57ba+/- interaction has not been reported before, nor has any 16p11.2 gene previously been linked to increased body size. These findings demonstrate that one pair of 16p11.2 homologs can regulate both brain and body phenotypes that are reflective of those in people with 16p11.2 deletion. Together, these findings suggest that dysregulation of ceramide pathways and calcium sensitive exocytosis underlies seizures and large body size associated with 16p11.2 homologs in zebrafish. The data inform consideration of mechanisms underlying human 16p11.2 deletion symptoms.
A Discrete-Time Servomechanism for The Regulation of Force and Position During Functional Neuromuscular Stimulation

Abstract Orthoses employing electrically stimulated muscles could be improved by the incorporation of closed-loop control systems to regulate the output of the muscle. The electrically stimulated muscle is modeled as a sampled data system and a digital controller is designed to satisfy stability, repeatability, linearity, and step response criteria over a wide range of recruitment gains. The digital controller can be implemented with a microprocessor and is amenable to adaptive control techniques. Simulation studies were conducted to evaluate the controller design. It was concluded that the design technique used can compensate for the muscle recruitment nonlinearities.
Mitotic progression following DNA damage enables pattern recognition within micronuclei

Inflammatory gene expression following genotoxic cancer therapy is well documented, yet the events underlying its induction remain poorly understood. Inflammatory cytokines modify the tumour microenvironment by recruiting immune cells and are critical for both local and systemic (abscopal) tumour responses to radiotherapy. A poorly understood feature of these responses is the delayed onset (days), in contrast to the acute DNA-damage responses that occur in minutes to hours. Such dichotomous kinetics implicate additional rate-limiting steps that are essential for DNA-damage-induced inflammation. Here we show that cell cycle progression through mitosis following double-stranded DNA breaks leads to the formation of micronuclei, which precede activation of inflammatory signalling and are a repository for the pattern-recognition receptor cyclic GMP-AMP synthase (cGAS). Inhibiting progression through mitosis or loss of pattern recognition by stimulator of interferon genes (STING)-cGAS impaired interferon signalling. Moreover, STING loss prevented the regression of abscopal tumours in the context of ionizing radiation and immune checkpoint blockade in vivo. These findings implicate temporal modulation of the cell cycle as an important consideration in the context of therapeutic strategies that combine genotoxic agents with immune checkpoint blockade.
Endocrine Studies in a Male Patient with Choriocarcinoma and Gynecomastia

Sex hormone profiles were studied in serum and tumor extracts of a man with pulmonary choriocarcinoma and gynecomastia. Although levels of serum estrogens were elevated as expected, serum androgen levels were uncharacteristically quite high. Tumor extract contained increased quantities of both androgens and estrogens when compared with surrounding normal lung tissue, but lacked the enzymes necessary for androgen biosynthesis while retaining aromatase activity. It is concluded that unlike the usual male patient with choriocarcinoma, the tumor-derived beta-human chorionic gonadotropin stimulated testicular androgen production. These androgens were in turn concentrated by the tumor and converted in part to estrogens. Furthermore, gynecomastia can occur even in the face of high serum androgen concentrations provided total estrogen levels are also disproportionately elevated.
Seven Challenges in Parallel SAT Solving

This paper provides a broad overview of the situation in Parallel SAT Solving. A set of challenges to researchers is presented which, we believe, must be met to ensure the practical applicability of Parallel SAT Solvers in the future. All these challenges are described informally, but put into perspective with related research results, and a (subjective) grading of difficulty for each of them is provided.
Stabilization of Linear Systems with Bounded Controls

Abstract Linear systems with saturated controls can be smoothly stabilized as long as certain natural controllability and eigenvalue conditions hold, as shown in a previous paper by the authors. Generalizing an idea of Teel, we show here how to obtain these stabilizers using very simple combinations of saturation nonlinearities —in neural network terms, sigmoidal feedforward nets.
A geometric method for eigenvalue problems with low-rank perturbations.

We consider the problem of finding the spectrum of an operator taking the form of a low-rank (rank one or two) non-normal perturbation of a well-understood operator, motivated by a number of proble...
Do parliamentary gender quotas decrease gender inequality? The case of African countries

Many countries in Africa score very low on gender equality measures; yet, they have some of the highest percentages of women in parliament. They have managed to achieve significant representation of women in government through fast track measures such as the implementation of gender quotas. In the context of fast track reform, this paper evaluates the effectiveness of such parliamentary gender quotas in general, and in particular of different types of quotas, for improving gender equality in African countries. Our empirical results suggest that although all mandated quota systems lead to an increase in the number of women in policy-making, the type of quota affects the de facto ability of women in parliament to influence legislative agendas and ultimately to improve the lives of women. Our findings have implications for the design of affirmative action measures targeting women’s participation in the political process.
Divergent neural responses to narrative speech in disorders of consciousness.

Objective Clinical assessment of auditory attention in patients with disorders of consciousness is often limited by motor impairment. Here, we employ intersubject correlations among electroencephalography responses to naturalistic speech in order to assay auditory attention among patients and healthy controls. Methods Electroencephalographic data were recorded from 20 subjects with disorders of consciousness and 14 healthy controls during of two narrative audio stimuli, presented both forwards and time-reversed. Intersubject correlation of evoked electroencephalography signals were calculated, comparing responses of both groups to those of the healthy control subjects. This analysis was performed blinded and subsequently compared to the diagnostic status of each patient based on the Coma Recovery Scale-Revised. Results Subjects with disorders of consciousness exhibit significantly lower intersubject correlation than healthy controls during narrative speech. Additionally, while healthy subjects had higher intersubject correlation values in forwards versus backwards presentation, neural responses did not vary significantly with the direction of playback in subjects with disorders of consciousness. Increased intersubject correlation values in the backward speech condition were noted with improving disorder of consciousness diagnosis, both in cross-sectional analysis and in a subset of patients with longitudinal data. Interpretation Intersubject correlation of neural responses to narrative speech audition differentiates healthy controls from patients and appears to index clinical diagnoses in disorders of consciousness.
Surface obstacles in pulsatile flow

Flows past obstacles mounted on flat surfaces have been widely studied due to their ubiquity in nature and engineering. For nearly all of these studies, the freestream flow over the obstacle was steady, i.e., constant velocity, unidirectional flow. Unsteady, pulsatile flows occur frequently in biology, geophysics, biomedical engineering, etc. Our study is aimed at extending the comprehensive knowledge base that exists for steady flows to considerably more complex pulsatile flows. Characterizing the vortex and wake dynamics of flows around surface obstacles embedded in pulsatile flows can provide insights into the underlying physics in all wake and junction flows. In this study, we experimentally investigate the wake of two canonical obstacles: a cube and a circular cylinder with an aspect ratio of unity. Our previous studies of a surface-mounted hemisphere in pulsatile flow are used as a baseline for these two new, more complex geometries. Phase-averaged PIV and hot-wire anemometry are used to characterize the dynamics of coherent structures in the wake and at the windward junction of the obstacles. Complex physics occur during the deceleration phase of the pulsatile inflow. We propose a framework for understanding these physics based on self-induced vortex propagation, similar to the phenomena exhibited by vortex rings.
Risk of punishment influences discrete and coordinated encoding of reward-guided actions by prefrontal cortex and VTA neurons

When deciding what to do, we usually try to predict the likely outcomes of our actions. This helps us choose behaviors that will lead to positive outcomes, or rewards, and avoid those that will lead to negative outcomes, or punishments. But in practice, actions that offer the possibility of reward often involve varying degrees of risk. When animals forage for food, for example, they risk encountering a predator. In our complex social world, applying for a job or asking someone out on a date means risking rejection. Being able to weigh up the likelihood of positive and negative outcomes is vital for effective decision-making. Park and Moghaddam have now studied how the brain’s reward system takes account of possible negative outcomes. Rats learned to poke their noses into a window inside a testing box whenever a light came on, to earn a sugar reward. The rats completed three blocks of trials. During the first block, they received only rewards. But for a few trials during the second and third blocks, they also received a mild electric shock as well as their reward. Throughout the task, Park and Moghaddam monitored the activity of two regions of the brain that encode rewards, the ventral tegmental area (or VTA for short) and the medial prefrontal cortex. The VTA sits deep within the brain and produces the brain’s reward chemical, dopamine. The prefrontal cortex is at the front of the brain and helps support cognition. In the reward-only block of trials, neurons in the VTA synchronized their firing with neurons in the prefrontal cortex. In blocks two and three, where there was a risk of shock, this synchrony decreased. This suggests that the prefrontal cortex takes greater control of decision-making when an unpleasant outcome is possible. Consistently overestimating the risk of things going wrong will lead to anxiety. Underestimating the risks will lead to impulsivity and poor decision-making. Park and Moghaddam’s experiment offers a way to study the mechanisms underlying these processes in animals. The results also suggest that using scalp electrodes to track prefrontal cortex activity in patients could be helpful in clinical trials for anxiety or impulse-control disorders.
Distributed quantum sensing using continuous-variable multipartite entanglement

Distributed quantum sensing uses quantum correlations between multiple sensors to enhance the measurement of unknown parameters beyond the limits of unentangled systems. We describe a sensing scheme that uses continuous-variable multipartite entanglement to enhance distributed sensing of field-quadrature displacement. By dividing a squeezed-vacuum state between multiple homodyne-sensor nodes using a lossless beam-splitter array, we obtain a root-mean-square (rms) estimation error that scales inversely with the number of nodes (Heisenberg scaling), whereas the rms error of a distributed sensor that does not exploit entanglement is inversely proportional to the square root of the number of nodes (standard quantum limit scaling). Our sensor's scaling advantage is destroyed by loss, but it nevertheless retains an rms-error advantage in settings in which there is moderate loss. Our distributed sensing scheme can be used to calibrate continuous-variable quantum key distribution networks, to perform multiple-sensor cold-atom temperature measurements, and to do distributed interferometric phase sensing.
The Art of Rhetorical Traps in Civilian Self-Protection

A common refrain is that ‘talk’ is cheap, yet nobody likes their inconsistencies being pointed out. With this in mind, dialogue, and specifically ‘rhetorical traps’, can be an effective nonviolent ...
Improving the Transduction of Bone Marrow–Derived Cells with an Integrase-Defective Lentiviral Vector

In lentiviral vector (LV) applications where transient transgene expression is sufficient, integrase-defective lentiviral vectors (IDLVs) are beneficial for reducing the potential for off-target effects associated with insertional mutagenesis. It was previously demonstrated that human RPE65 mRNA expression from an integrating lentiviral vector (ILV) induces endogenous Rpe65 and Cralbp mRNA expression in murine bone marrow-derived cells (BMDCs), initiating programming of the cells to retinal pigment epithelium (RPE)-like cells. These cells regenerate RPE in retinal degeneration models when injected systemically. As transient expression of RPE65 is sufficient to activate endogenous RPE-associated genes for programming BMDCs, use of an ILV is an unnecessary risk. In this study, an IDLV expressing RPE65 (IDLV3-RPE65) was generated. Transduction with IDLV3-RPE65 is less efficient than the integrating vector (ILV3-RPE65). Therefore, IDLV3-RPE65 transduction was enhanced with a combination of preloading 20 × -concentrated viral supernatant on RetroNectin at a multiplicity of infection of 50 and transduction of BMDCs by low-speed centrifugation. RPE65 mRNA levels increased from ∼12-fold to ∼25-fold (p < 0.05) after modification of the IDLV3-RPE65 transduction protocol, achieving expression similar to the ∼27-fold (p < 0.05) increase observed with ILV3-RPE65. Additionally, the study shows that the same preparation of RetroNectin can be used to coat up to three wells with no reduction in transduction. Critically, IDLV3-RPE65 transduction initiates endogenous Rpe65 mRNA expression in murine BMDCs and Cralbp/CRALBP mRNA in both murine and human BMDCs, similar to expression observed in ILV3-RPE65-transduced cells. Systemic administration of ILV3-RPE65 or IDLV3-RPE65 programmed BMDCs in a mouse model of retinal degeneration is sufficient to retain visual function and reduce retinal degeneration compared to mice receiving no treatment or naive BMDC. It is concluded that IDLV3-RPE65 is appropriate for programming BMDCs to RPE-like cells.
Substernal reconstruction following esophagectomy: operation of last resort?

Background: The posterior mediastinum is the preferred location for reconstruction following esophagectomy. Occasionally alternative routes are required. We examined patient outcomes of esophageal reconstruction in order to determine whether substernal reconstruction (SR) is an equivalent alternative to orthotopic placement. Methods: Following IRB approval, we performed a retrospective review of all patients who underwent an esophagectomy from 1988–2014. Only patients reconstructed with a gastric conduit and cervical anastomosis by either substernal or posterior mediastinal (PM) routes were included in the study. Endpoints assessed included anastomotic leak rate, post-operative complications, reoperation, hospital length of stay, and 30- and 90-day mortality. Results: Thirty-three patients underwent SR and 182 had a PM gastric conduit with cervical anastomosis. The SR pathology was predominantly benign while PM was mostly malignant. Sixteen SR patients had a delayed reconstruction after prior diversion. Mean hospital LOS was longer in the SR group (P Conclusions: This single institution experience demonstrated no significant difference in mortality between substernal and PM reconstruction following esophagectomy. However, SR was associated with significantly increased LOS and morbidity, including a trend toward increased anastomotic leaks. SR reconstruction should probably be considered an option of last resort.
Microstructure of GaN Grown on (111) Si by MOCVD

Gallium nitride was grown on (111) Si by MOCVD by depositing an AlN buffer at 1080°C followed by GaN at 1060°C. The 2.2 μm layer cracked along {1-100} planes upon cooling to room temperature, but remained adherent. We were nonetheless able to examine the material between cracks with TEM. The character and arrangement of dislocations are much like those of GaN grown on Al2O3: ∼2/3 pure edge and ∼1/3 mixed (edge + screw), arranged in boundaries around domains of GaN that are slightly misoriented with respect to neighboring material. The 30 nm AlN buffer is continuous, indicating that AlN wets the Si, in contrast to GaN on Al2O3.
Macroeconomic impact of foot-and-mouth disease vaccination strategies for an outbreak in the Midwestern United States: A computable general equilibrium.

The impacts of alternative responses to a hypothetical foot-and-mouth disease (FMD) outbreak occurring in the Midwestern United States are estimated using the Regional Economic Modelling Incorporated Policy Insight + (REMI) computable general equilibrium model, with particular attention paid to the employment impact estimates. The impact on employment and GDP is estimated using forecasts of a 10-year period with disease outbreak duration up to 2 years. Fifteen different vaccination protocols are compared to a disease control protocol that relies on animal depopulation with no vaccination. Results show that over the 10-year study period, the strictly depopulation strategy that made no use of vaccination results in approximately 677,000 jobs lost with $47 billion GDP loss. Based on the analysis conducted, losses can be reduced through protocols that utilize vaccination strategies. Through a vaccinate-to-live strategy with the highest vaccination capacity and largest vaccination zone, savings can be as many as 509,000 jobs in comparison to the strategy that relies strictly on slaughter with no use of vaccination. By including detailed job losses by occupation, this study highlights the downstream employment effects and shows that job losses resulting from an FMD outbreak can go far beyond the farm sector impacts that have been reported in earlier studies. Understanding the impacts on employment by sector provides more actionable information than producer and consumer surplus estimates frequently reported in economic impact studies.
Affine Relativization: Unifying the Algebrization and Relativization Barriers

We strengthen existing evidence for the so-called “algebrization barrier.” Algebrization—short for algebraic relativization—was introduced by Aaronson and Wigderson (AW) (STOC 2008) to characterize proofs involving arithmetization, simulation, and other “current techniques.” However, unlike relativization, eligible statements under this notion do not seem to have basic closure properties, making it conceivable to take two proofs, both with algebrizing conclusions, and combine them to get a proof without. Further, the notion is undefined for most types of statements and does not seem to yield a general criterion by which we can tell, given a proof, whether it algebrizes. In fact, the very notion of an algebrizing proof is never made explicit, and casual attempts to define it are problematic. All these issues raise the question of what evidence, if any, is obtained by knowing whether some statement does or does not algebrize.We give a reformulation of algebrization without these shortcomings. First, we define what it means for any statement/proof to hold relative to any language, with no need to refer to devices like a Turing machine with an oracle tape. Our approach dispels the widespread misconception that the notion of oracle access is inherently tied to a computational model. We also connect relativizing statements to proofs, by showing that every proof that some statement relativizes is essentially a relativizing proof of that statement.We then define a statement/proof as relativizing affinely if it holds relative to every affine oracle—here an affine oracle is the result of a particular error correcting code applied to the characteristic string of a language. We show that every statement that AW declare as algebrizing does relativize affinely, in fact, has a proof that relativizes affinely, and that no such proof exists for any of the statements shown not-algebrizing by AW in the classical computation model.Our work complements, and goes beyond, the subsequent work by Impagliazzo, Kabanets, and Kolokolova (STOC 2009), which also proposes a reformulation of algebrization, but falls short of recovering some key results of AW, most notably regarding the NEXP versus P/poly question.Using our definitions, we obtain new streamlined proofs of several classic results in complexity, including PSPACE ⊂ IP and NEXP ⊂ MIP. This may be of separate interest.
Expressing Robot Incapability

Our goal is to enable robots to express their incapability, and to do so in a way that communicates both what they are trying to accomplish and why they are unable to accomplish it. We frame this as a trajectory optimization problem: maximize the similarity between the motion expressing incapability and what would amount to successful task execution, while obeying the physical limits of the robot. We introduce and evaluate candidate similarity measures, and show that one in particular generalizes to a range of tasks, while producing expressive motions that are tailored to each task. Our user study supports that our approach automatically generates motions expressing incapability that communicate both what and why to end-users, and improve their overall perception of the robot and willingness to collaborate with it in the future.
Single-case synthesis tools II: Comparing quantitative outcome measures.

Abstract Varying methods for evaluating the outcomes of single case research designs (SCD) are currently used in reviews and meta-analyses of interventions. Quantitative effect size measures are often presented alongside visual analysis conclusions. Six measures across two classes—overlap measures (percentage non-overlapping data, improvement rate difference, and Tau) and parametric within-case effect sizes (standardized mean difference and log response ratio [increasing and decreasing])—were compared to determine if choice of synthesis method within and across classes impacts conclusions regarding effectiveness. The effectiveness of sensory-based interventions (SBI), a commonly used class of treatments for young children, was evaluated. Separately from evaluations of rigor and quality, authors evaluated behavior change between baseline and SBI conditions. SBI were unlikely to result in positive behavior change across all measures except IRD. However, subgroup analyses resulted in variable conclusions, indicating that the choice of measures for SCD meta-analyses can impact conclusions. Suggestions for using the log response ratio in SCD meta-analyses and considerations for understanding variability in SCD meta-analysis conclusions are discussed.
Fast X-ray Oscillations During Magnetar Flares

The giant flares produced by highly magnetized neutron stars, "magnetars," are the brightest sources of high energy radiation outside our solar system. Serendipitous observations with NASA's Rossi X-ray Timing Explorer (RXTE) of the two most recent flares resulted in the discovery of high frequency oscillations in their X-ray fluxes. The frequencies of these oscillations range from approx. 20 Hz to as high as 1800 Hz, and may represent the first detection of global oscillation modes of neutron stars. Here I will present an observational and theoretical overview of these oscillations and discuss how they might allow us to probe neutron star interiors and dense matter physics.