cssi/SciSciGPT-SciSciNet huggingface dataset:
Herd immunity alters the conditions for performing dose schedule comparisons: an individual-based model of pneumococcal carriage.

There is great interest in the use of reduced dosing schedules for pneumococcal conjugate vaccines, a strategy premised on maintaining an acceptable level of protection against disease and carriage of the organism. We asked about the practicality of measuring differential effectiveness against carriage in a population with and without widespread use of the vaccine for infants. We adapted an existing transmission-dynamic, individual-based stochastic model fitted to the prevaccine epidemiology of pneumococcal carriage in the United States, and compared the observed vaccine-type carriage prevalence in different arms of a simulated trial with one, two, or three infant doses plus a 12-month booster. Using these simulations, we calculated vaccine efficacy that would be estimated at different times post-enrollment in the trial and calculated required sample sizes to see a difference in carriage prevalence. In a pneumococcal conjugate vaccine (PCV)-naive population, the difference in vaccine-type (VT) pneumococcal carriage prevalence between trial arms was less than 7% and varied with sampling time. In a population already receiving routine PCV administration, VT pneumococcal prevalence is nearly indistinguishable between trial arms. Relative efficacy of different dosing schedules was strongly dependent on the time between enrollment and sampling, with maximal prevalence differences reached 1–3 years post-enrollment. Moreover, vaccine efficacy estimates were typically slightly higher in trials in communities already receiving vaccination. Despite this, much larger sample sizes—by more than an order of magnitude—are required for a vaccine trial conducted in a population receiving routine PCV administration as compared to in a PCV-naive population. These findings highlight some underappreciated aspects of clinical trials of pneumococcal conjugate vaccines with efficacy endpoints, such as the context- and time-dependence of efficacy estimates. They support the wisdom of conducting comparative dose schedule trials of conjugate vaccine effects on carriage in vaccine-naive populations.
The anti-Ramsey problem for the Sidon equation

Abstract For n ≥ k ≥ 4 , let A R X + Y = Z + T k ( n ) be the maximum number of rainbow solutions to the Sidon equation X + Y = Z + T over all k -colorings c : [ n ] → [ k ] . It can be shown that the total number of solutions in [ n ] to the Sidon equation is n 3 ∕ 12 + O ( n 2 ) and so, trivially, A R X + Y = Z + T k ( n ) ≤ n 3 ∕ 12 + O ( n 2 ) . We improve this upper bound to A R X + Y = Z + T k ( n ) ≤ 1 12 − 1 24 k n 3 + O k ( n 2 ) for all n ≥ k ≥ 4 . Furthermore, we give an explicit k -coloring of [ n ] with more rainbow solutions to the Sidon equation than a random k -coloring, and gives a lower bound of 1 12 − 1 3 k n 3 − O k ( n 2 ) ≤ A R X + Y = Z + T k ( n ) . When k = 4 , we use a different approach based on additive energy to obtain an upper bound of 3 n 3 ∕ 96 + O ( n 2 ) , whereas our lower bound is 2 n 3 ∕ 96 − O ( n 2 ) in this case.
Effect of pressure on the physical properties of the superconductor NiBi3.

We present an experimental study of the superconducting properties of NiBi3 as a function of pressure by means of resistivity and magnetization measurements and combine our results with density functional theory calculations of the band structure under pressure. We find a moderate suppression of the critical temperature from K to K by pressures up to 2 GPa. By taking into account the change of the band structure as a function of pressure, we argue that the decrease in is consistent with conventional, electron–phonon-mediated BCS-type superconductivity.
Does the Media Help or Hurt Retail Investors during the IPO Quiet Period

Abstract We examine how the media influences retail trade and market returns during the “quiet period” that follows a firm’s IPO. We find that more media coverage during this period is associated with more purchases by retail investors and that such purchases are attention-driven, rather than information-based. Further, these retail trades are negatively associated with stock returns at the firm’s first earnings announcement post-IPO. Our results suggest that media coverage, combined with market frictions that limit price efficiency in the post-IPO period, leads to worse investing outcomes for retail investors.
Variational Sequential Labelers for Semi-Supervised Learning

We introduce a family of multitask variational methods for semi-supervised sequence labeling. Our model family consists of a latent-variable generative model and a discriminative labeler. The generative models use latent variables to define the conditional probability of a word given its context, drawing inspiration from word prediction objectives commonly used in learning word embeddings. The labeler helps inject discriminative information into the latent space. We explore several latent variable configurations, including ones with hierarchical structure, which enables the model to account for both label-specific and word-specific information. Our models consistently outperform standard sequential baselines on 8 sequence labeling datasets, and improve further with unlabeled data.
The Sharing Economy as an Equalizing Economy

Economic equality is often said to be the key problem of our time. But information technology dematerializes the world in ways that are helpful to the 99 percent, because information can be shared. This essay looks how one fruit of the information revolution—the sharing economy—has important equalizing features on both its supply and demand side. First, on the supply side, the intermediaries in the sharing economy, like Airbnb and Uber, allow owners of housing and cars to monetize their most important capital assets. The gig aspect of this economy also creates spot markets in jobs that have flexible hours and monetize people’s passions, such as cooking meals in their home. Such benefits make these jobs even more valuable than the earnings that show up imperfectly in income statistics. The law and economics analysis of Hernando De Soto has shown how creating property rights and more formal markets can help those of modest means in the developing world. The sharing economy performs a similar function for people of modest means in the developed world. Second, on the demand side, the sharing economy also creates gains for consumers that largely go to the 99 percent. Airbnb finds them cheaper accommodations in places that may have been unaffordable. But the advantages go beyond price. Summoning a ridesharing car almost anywhere with the press of smart phone is a much closer approximation of having a chauffeur— a hallmark of wealth—than hailing a taxi. The law and economics analysis of Ronald Coase shows how replacing such physical agents with online agents redounds largely to the benefit of those with modest incomes. If the sharing economy has equalizing as well as efficiency features, regulations must be careful not to disturb them. But because the sharing economy permits new entry into markets, incumbents will respond with new regulatory efforts to hamper it. The essay provides a taxonomy of the different kinds of regulation to help preserve the equalizing features from being impaired. The essay ends by showing how the sharing economy more generally problematizes the conventional story of growing material inequality. The dematerialization of the world provides greater opportunities for broadly shared consumption, like that on Facebook, and improves working conditions, particularly for the middling classes. Only by taking account of these trends can we understand the changing relative material conditions of people.
Random shuffles on trees using extended promotion

The Tsetlin library is a very well-studied model for the way an arrangement of books on a library shelf evolves over time. One of the most interesting properties of this Markov chain is that its sp...
Revisiting precautionary saving under ambiguity

Abstract I study the two-period consumption-saving problem with non-separable utility under ambiguity. Under smooth ambiguity aversion, ambiguity and greater ambiguity aversion raise optimal saving. When relative prudence in ambiguity preferences does not exceed 2, agents who perceive greater ambiguity have a higher demand for saving. While a convex marginal ambiguity function is not sufficient for precautionary saving in time-separable models (Berger, 2014), I show that it is not even necessary in a time non-separable setting.
Vision-Based High-Speed Driving With a Deep Dynamic Observer

In this letter, we present a framework for combining deep learning-based road detection, particle filters, and model predictive control (MPC) to drive aggressively using only a monocular camera, IMU, and wheel speed sensors. This framework uses deep convolutional neural networks combined with LSTMs to learn a local cost map representation of the track in front of the vehicle. A particle filter uses this dynamic observation model to localize in a schematic map, and MPC is used to drive aggressively using this particle filter based state estimate. We show extensive real world testing results and demonstrate reliable operation of the vehicle at the friction limits on a complex dirt track. We reach speeds above 27 m/h (12 m/s) on a dirt track with a 105 ft (32 m) long straight using our 1:5 scale test vehicle.
Efficacy of pre-operative stereotactic radiosurgery followed by surgical resection and correlative radiobiological analysis for patients with 1–4 brain metastases: study protocol for a phase II trial

Stereotactic radiosurgery (SRS) has emerged as a common adjuvant modality used with surgery for resectable brain metastases (BMs). However, the optimal sequence of the multi-modality therapy has not been established. The goal of the study is to evaluate 6-month local control utilizing pre-operative SRS followed by surgical resection for patients with 1–4 brain metastases. This prospective, single arm, phase II trial will recruit patients with up to 4 brain metastases and at least one resectable lesion. All lesions will be treated with SRS and symptomatic lesions will be resected within 1–4 days after SRS. Patients will be monitored for 6-month local control, in-brain progression free survival, distant in-brain failure, rate of leptomeningeal spread, radiation necrosis and overall survival. Additionally, we will also perform correlative radiobiological molecular studies to assess the effect of radiation dosing on the tumor tissue and clinical outcomes. We expect that pre-operative SRS to the gross tumor prior to surgical resection will improve local control and decrease leptomeningeal failure. Our study is the second prospective trial to investigate the efficacy of pre-operative SRS in the treatment of multiple BMs. In addition, the correlative molecular studies will be the first to investigate early response of BMs at a cellular and genetic level in response to radiation doses and potentially provide molecular prognostic markers for local control and overall survival. Clinicaltrials.gov identifier: NCT03398694 (registration date: January 12, 2018).
Towards GAN Benchmarks Which Require Generalization

For many evaluation metrics commonly used as benchmarks for unconditional image generation, trivially memorizing the training set attains a better score than models which are considered state-of-the-art; we consider this problematic. We clarify a necessary condition for an evaluation metric not to behave this way: estimating the function must require a large sample from the model. In search of such a metric, we turn to neural network divergences (NNDs), which are defined in terms of a neural network trained to distinguish between distributions. The resulting benchmarks cannot be "won" by training set memorization, while still being perceptually correlated and computable only from samples. We survey past work on using NNDs for evaluation and implement an example black-box metric based on these ideas. Through experimental validation we show that it can effectively measure diversity, sample quality, and generalization.
Solar Irradiance Forecasting in Remote Microgrids Using Markov Switching Model

Photovoltaic (PV) systems integration is increasingly being used to reduce fuel consumption in diesel-based remote microgrids. However, uncertainty and low correlation of PV power availability with load reduces the benefits of PV integration. These challenges can be handled by introducing reserve. However, this leads to increased operational cost. Solar irradiance forecasting helps to reduce reserve requirement, thereby improving the utilization of PV energy. This paper presents a new solar irradiance forecasting method for remote microgrids based on the Markov switching model. This method uses locally available data to predict one-day-ahead solar irradiance for scheduling energy resources in remote microgrids. The model considers past solar irradiance data, clear sky irradiance, and Fourier basis expansions to create linear models for three regimes or states: high, medium, and low energy regimes for days corresponding to sunny, mildly cloudy, and extremely cloudy days, respectively. The case study for Brookings, SD, USA, discussed in this paper, resulted in an average mean absolute percentage error of 31.8% for five years, from 2001 to 2005, with higher errors during summer months than during winter months.
Current Status of Therapy in Glomerulonephritis

The term glomerulonephritis is applied to inflammatory diseases of the renal glomeruli. Acute and chronic or latent stages may be recognized clinically and anatomically. Acute Glomerulonephritis Acute glomerulonephritis is a disorder associated with the appearance of protein, erythrocytes, leukocytes, and renal tubular epithelial cells in the urine. Red blood cell casts may be present and serve to distinguish the disease sharply from others in which bleeding occurs distal to the glomerulus. The full blown clinical picture is completed by the addition of hypertension, edema, oliguria, azotemia, and, in the more severely ill, cardiac enlargement with or without congestive failure. Convulsions occur in a very few cases. Nearly all illnesses exhibiting this pattern, and a high proportion of all others in which glomerular bleeding occurs, are the result of group A hemolytic streptococcus infection. Only a few strains of these organisms, notably those of types 4, 12, and 49 (Redlake), are
Preservice Secondary Mathematics Teachers’ Statistical Knowledge: A Snapshot of Strengths and Weaknesses

Amid the implementation of new curriculum standard regarding statistics and new recommendations for preservice secondary mathematics teachers (PSMTs) to teach statistics, there is a need to examine...
Linear Statistical Models for Causation: A Critical Review†

We review the basis for inferring causation by means of linear statistical models. Parameters should be stable under interventions, and so should error distributions. There are also statistical conditions that must be satisfied. Stability is difficult to establish a priori, and the statistical conditions are equally problematic. Therefore, causal relationships are seldom to be inferred from a data set by running regressions, unless there is substantial prior knowledge about the mechanisms that generated the data. Keywords: association; causation; latent variables; linear models; regression; structural equation models
Association between obesity and bacterial vaginosis as assessed by Nugent score

Background Bacterial vaginosis is 1 of the most common vaginal conditions in the United States. Recent studies have suggested that obese women have an abnormal microbiota reminiscent of bacterial vaginosis; however, few studies have investigated the prevalence of bacterial vaginosis in overweight and obese populations. Moreover, despite the increased prevalence of obesity and bacterial vaginosis in black women, it is not known whether racial disparities exist in the relationship between obesity and bacterial vaginosis. Objective The objective of this study was to examine the relationship between body mass index and bacterial vaginosis as determined by Nugent score and to determine the influence of race in this context. Study Design We performed a cross-sectional study using patient data and vaginal smears from 5918 participants of the Contraceptive CHOICE Project. Gram-stained vaginal smears were scored with the Nugent method and categorized as bacterial vaginosis–negative (Nugent score, 0–3), bacterial vaginosis–intermediate (Nugent score, 4–6), or bacterial vaginosis–positive (Nugent score, 7–10). Body mass index was determined with Centers for Disease Control and Prevention guidelines, and obese individuals were categorized as class I, II, or III obese based on National Institutes of Health and World Health Organization body mass index parameters. Linear regression was used to model mean differences in Nugent scores; Poisson regression with robust error variance was used to model prevalence of bacterial vaginosis. Results In our cohort, 50.7% of participants were black; 41.5% were white, and 5.1% were of Hispanic ethnicity; the average age of 25.3 years old. Overall, 28.1% of participants were bacterial vaginosis–positive. Bacterial vaginosis was prevalent in 21.3% of lean, 30.4% of overweight, and 34.5% of obese women (P Conclusion Overweight and obese women have higher Nugent scores and a greater occurrence of bacterial vaginosis compared with lean women. Black women have a greater prevalence of bacterial vaginosis independent of their body mass index compared with white women.
Exposure Characterization of Haloacetic Acids in Humans for Exposure and Risk Assessment Applications: An Exploratory Study

Disinfected water is the major source of haloacetic acids (HAAs) in humans, but their inter- and intra-individual variability for exposure and risk assessment applications is under-researched. Thus, we measured HAAs in cross-sectional and longitudinal urine and water specimens from 17 individuals. Five regulated HAAs-mono, di, and trichloroacetic acid (MCAA, DCAA, and TCAA) and mono- and dibromoacetic acid (MBAA and DBAA)-and one unregulated HAA-bromochloroacetic acid (BCAA)-were measured. Urinary DCAA, MBAA, DBAA, and BCAA levels were always below the limits of detection (LOD). Measured levels and interindividual variability of urinary MCAA were higher than urinary TCAA. Longitudinal urinary specimens showed MCAA levels peaked in after-shower specimens, while TCAA levels remain unchanged. Correlation between urinary MCAA and TCAA was moderate but statistically significant. The prevalence of MCAA and TCAA in urine suggest they can be considered as biomarkers of HAA. Peak urinary MCAA in post-shower specimens suggest MCAA captures short-term exposure via dermal and/or inhalation, while urinary TCAA captures long-term exposure via ingestion. However, further research is warranted in a large pool of participants to test the reliability of MCAA as exposure biomarker.
Strategic Classification

Machine learning relies on the assumption that unseen test instances of a classification problem follow the same distribution as observed training data. However, this principle can break down when machine learning is used to make important decisions about the welfare (employment, education, health) of strategic individuals. Knowing information about the classifier, such individuals may manipulate their attributes in order to obtain a better classification outcome. As a result of this behavior -- often referred to as gaming -- the performance of the classifier may deteriorate sharply. Indeed, gaming is a well-known obstacle for using machine learning methods in practice; in financial policy-making, the problem is widely known as Goodhart's law. In this paper, we formalize the problem, and pursue algorithms for learning classifiers that are robust to gaming.We model classification as a sequential game between a player named "Jury" and a player named "Contestant." Jury designs a classifier, and Contestant receives an input to the classifier drawn from a distribution. Before being classified, Contestant may change his input based on Jury's classifier. However, Contestant incurs a cost for these changes according to a cost function. Jury's goal is to achieve high classification accuracy with respect to Contestant's original input and some underlying target classification function, assuming Contestant plays best response. Contestant's goal is to achieve a favorable classification outcome while taking into account the cost of achieving it.For a natural class of "separable" cost functions, and certain generalizations, we obtain computationally efficient learning algorithms which are near optimal, achieving a classification error that is arbitrarily close to the theoretical minimum. Surprisingly, our algorithms are efficient even on concept classes that are computationally hard to learn. For general cost functions, designing an approximately optimal strategy-proof classifier, for inverse-polynomial approximation, is NP-hard.
Diversity and Exploration in Social Learning

In consumer search, there is a set of items. An agent has a prior over her value for each item and can pay a cost to learn the instantiation of her value. After exploring a subset of items, the agent chooses one and obtains a payoff equal to its value minus the search cost. We consider a sequential model of consumer search in which agents' values are correlated and each agent updates her priors based on the exploration of past agents before performing her search. Specifically, we assume the value is the sum of a common-value component, called the quality, and a subjective score. Fixing the variance of the total value, we say a population is more diverse if the subjective score has a larger variance. We ask how diversity impacts average utility. We show that intermediate diversity levels yield significantly higher social utility than the extreme cases of no diversity (when agents under-explore) or full diversity (when agents are unable to learn from each other) and quantify how the impact of the diversity level changes depending on the time spent searching.
The political economy of legal titling

The libertarian case for legal titling is that formalization of the economic (de facto) rights of those who own land and buildings improves prospects for capitalism and, ultimately, development. Although all rich countries have private property rights, we argue that the success of legal titling depends on a certain kind of state—what we call a property-protecting state—that is often missing in developing countries. We use insights from Austrian economics, public choice, and institutional economics to clarify the political basis for legal titling to improve land tenure security. Evidence from Afghanistan shows that legal titling has not worked because the country does not have a property-protecting state. We suggest focusing on improving political institutions before investing in legal titling. In the meantime, it makes more sense to register land ownership at the community level, without the state.
Loss aversion and the quantity–quality tradeoff

Firms face an optimization problem that requires a maximal quantity output given a quality constraint. But how do firms incentivize quantity and quality to meet these dual goals, and what role do behavioral factors, such as loss aversion, play in the tradeoffs workers face? We address these questions with a theoretical model and an experiment in which participants are paid for both quantity and quality of a real effort task. Consistent with basic economic theory, higher quality incentives encourage participants to shift their attention from quantity to quality. However, we also find that loss averse participants shift their attention from quality to quantity to a greater degree when quality is weakly incentivized. These results can inform managers of appropriate ways to structure contracts, and suggest benefits to personalizing contracts based on individual behavioral characteristics.
Representing Formal Languages: A Comparison Between Finite Automata and Recurrent Neural Networks

We investigate the internal representations that a recurrent neural network (RNN) uses while learning to recognize a regular formal language. Specifically, we train a RNN on positive and negative examples from a regular language, and ask if there is a simple decoding function that maps states of this RNN to states of the minimal deterministic finite automaton (MDFA) for the language. Our experiments show that such a decoding function indeed exists, and that it maps states of the RNN not to MDFA states, but to states of an {\em abstraction} obtained by clustering small sets of MDFA states into "superstates". A qualitative analysis reveals that the abstraction often has a simple interpretation. Overall, the results suggest a strong structural relationship between internal representations used by RNNs and finite automata, and explain the well-known ability of RNNs to recognize formal grammatical structure.
Robust Alignment for Panoramic Stitching Via an Exact Rank Constraint

We study the problem of image alignment for panoramic stitching. Unlike most existing approaches that are feature-based, our algorithm works on pixels directly, and accounts for errors across the whole images globally. Technically, we formulate the alignment problem as rank-1 and sparse matrix decomposition over transformed images, and develop an efficient algorithm for solving this challenging non-convex optimization problem. The algorithm reduces to solving a sequence of subproblems, where we analytically establish exact recovery conditions, convergence and optimality, together with convergence rate and complexity. We generalize it to simultaneously align multiple images and recover multiple homographies, extending its application scope toward vast majority of practical scenarios. The experimental results demonstrate that the proposed algorithm is capable of more accurately aligning the images and generating higher quality stitched images than the state-of-the-art methods.
Decomposing the Accrual Premium: The Evidence from Two Markets

We decompose the accrual premium and study its components in the debt and equity markets. We show that the importance of each accrual component depends on the sample and the type of market considered. The short-term accruals component is primarily observed in equity markets, among small and young companies, which is consistent with mispricing arguments. The long-term accruals premium is consistently positive and significant in different samples and markets. This component reflects growth in capital expenditures, and it is counter-cyclical and predictable, which is in line with investment-based explanations. Finally, the financial accruals component does not generate predictability.
Microwave enhanced cross-coupling reactions involving alkenyl- and alkynyltrifluoroborates

Cross-coupling reactions of potassium arylvinyltrifluoroborates with aryl iodides in the presence of a palladium catalyst occur rapidly utilizing microwave irradiation. The coupled products are produced in excellent yields. Alkynyltrifluoroborates also undergo the coupling reaction.
The Relationship between Age, Neural Differentiation, and Memory Performance.

Healthy aging is associated with decreased neural selectivity (dedifferentiation) in category-selective cortical regions. This finding has prompted the suggestion that dedifferentiation contributes to age-related cognitive decline. Consistent with this possibility, dedifferentiation has been reported to negatively correlate with fluid intelligence in older adults. Here, we examined whether dedifferentiation is associated with performance in another cognitive domain—episodic memory—that is also highly vulnerable to aging. Given the proposed role of dedifferentiation in age-related cognitive decline, we predicted there would be a stronger link between dedifferentiation and episodic memory performance in older than in younger adults. Young (18–30 years) and older (64–75 years) male and female humans underwent fMRI scanning while viewing images of objects and scenes before a subsequent recognition memory test. We computed a differentiation index in two regions of interest (ROIs): parahippocampal place area (PPA) and lateral occipital complex (LOC). This index quantified the selectivity of the BOLD response to preferred versus nonpreferred category of an ROI (scenes for PPA, objects for LOC). The differentiation index in the PPA, but not the LOC, was lower in older than in younger adults. Additionally, the PPA differentiation index predicted recognition memory performance for the studied items. This relationship was independent of and not moderated by age. The PPA differentiation index also predicted performance on a latent “fluency” factor derived from a neuropsychological test battery; this relationship was also age invariant. These findings suggest that two independent factors, one associated with age, and the other with cognitive performance, influence neural differentiation. SIGNIFICANCE STATEMENT Aging is associated with neural dedifferentiation—reduced neural selectivity in “category-selective” cortical brain regions—which has been proposed to contribute to cognitive aging. Here, we examined whether neural differentiation is predictive of episodic memory performance, and whether the relationship is moderated by age. A neural differentiation index was estimated for scene-selective (PPA) and object-selective (LOC) cortical regions while participants studied images for a subsequent memory test. Age-related reductions were observed for the PPA, but not for the LOC, differentiation index. Importantly, the PPA differentiation index demonstrated age-invariant correlations with subsequent memory performance and a fluency factor derived from a neuropsychological battery. Together, these findings suggest that neural differentiation is associated with two independent factors: age and cognitive performance.
NOVEL CYCLIZATION REACTIONS OF DICHLOROAZODIENES

The novel cyclization reactions of the in-situ generated 1-carboxyethyl-3-phenyl-4,4-dichloroazodiene were found to give N-aminopyrroles and pyridazines when combined with acyclic enamines, Table 1. However, reactions with cyclic enamines gave the N-aminopyrroles, pyridazines, a dihydropyridazine as products as well as the non-cyclized enamine intermediates, Table 2. The enamines 10c and 11c could be converted to the N-aminopyrroles 10a and 11a simply upon heating to higher temperatures indicating a stepwise mechanism. The example described here are the first reported cyclization reactions for dichloroazodienes.
An expedient total synthesis of (±)-caparratriene

Abstract (±)-Caparratriene has been synthesized by two succinct routes. The first relies on two Wittig reactions and produces (±)-caparratriene and its 2Z isomer as an inseparable 2:1 mixture. The second more efficient synthesis produces only the naturally occurring 2E isomer and proceeds in 36% overall yield. The key step in this short synthesis is the Suzuki coupling of E-2-bromo-2-butene with the E-vinyl borane derived from 4,8-dimethyl-7-nonen-1-yne.
Species and cell-type properties of classically defined human and rodent neurons and glia

Determination of the molecular properties of genetically targeted cell types has led to fundamental insights into mouse brain function and dysfunction. Here, we report an efficient strategy for precise exploration of gene expression and epigenetic events in specific cell types in a range of species, including postmortem human brain. We demonstrate that classically defined, homologous neuronal and glial cell types differ between rodent and human by the expression of hundreds of orthologous, cell specific genes. Confirmation that these genes are differentially active was obtained using epigenetic mapping and immunofluorescence localization. Studies of sixteen human postmortem brains revealed gender specific transcriptional differences, cell-specific molecular responses to aging, and the induction of a shared, robust response to an unknown external event evident in three donor samples. Our data establish a comprehensive approach for analysis of molecular events associated with specific circuits and cell types in a wide variety of human conditions.
Reliable individual differences in fine-grained cortical functional architecture

Fine-grained functional organization of cortex is not well-conserved across individuals. As a result, individual differences in cortical functional architecture are confounded by topographic idiosyncrasies-i.e., differences in functional-anatomical correspondence. In this study, we used hyperalignment to align information encoded in topographically variable patterns to study individual differences in fine-grained cortical functional architecture in a common representational space. We characterized the structure of individual differences using three common functional indices, and assessed the reliability of this structure across independent samples of data in a natural vision paradigm. Hyperalignment markedly improved the reliability of individual differences across all three indices by resolving topographic idiosyncrasies and accommodating information encoded in spatially fine-grained response patterns. Our results demonstrate that substantial individual differences in cortical functional architecture exist at fine spatial scales, but are inaccessible with anatomical normalization alone.
New developments in the chemistry of silicon selenides

Abstract The development of a convenient route to selenide anions under conditions that permit the use of organosilicon halides opened the way to a variety of organosilicon selenides. Reactivity studies on these selenide anions as well as our efforts to prepare cyclosilselenanes and subsequent photolysis and thermolysis studies are summarized.
Synthesis of Potentially Carcinogenic Higher Oxidized Metabolites of Dibenz[a,j]anthracene and Benzo[c]chrysene

Bis(dihydrodiols) and other higher oxidized metabolites are implicated as active carcinogenic metabolites of polycyclic aromatic hydrocarbons, such as dibenz[a,j]anthracene, that possess more than one bay region in the molecule. The bis(dihydrodiol) metabolites may potentially undergo further metabolism to mono- or diepoxides that combine covalently with DNA or undergo conversion to bis(catechols) that enter into a redox cycle with O2 to form reactive oxygen species that attack DNA. This paper reports convenient syntheses of the terminal ring bis(dihydrodiol) derivatives of dibenz[a,j]anthracene (5) and benzo[c]chrysene (6) via routes that involve in the key steps double oxidative photocyclization of tetramethoxy-substituted diolefins. The latter are synthesized via double Wittig reaction of a bis(phosphonium) salt with 2,3-dimethoxybenzaldehyde. Demethylation of the bis(catechol) products followed by acetylation and reduction with NaBH4 in the presence of O2 affords the bis(dihydrodiol) products. Several...
Extended applications and potential limitations of ring-fused 2,3-oxazolidinone thioglycosides in glycoconjugate synthesis

Abstract The utility of ring-fused 2,3-oxazolidinone derivatives of 2-amino-2-deoxy-thioglycosides in the synthesis of glycopeptide intermediates and building blocks for the synthesis of heparan sulfate oligosaccharides is reported. These unique ring-fused monosaccharides afford a novel and efficient route to alpha-O-linked 2-amino-2-deoxy amino acid derivatives and heparan sulfate oligosaccharide intermediates.
Total synthesis of dysiherbaine.

A convergent total synthesis of the marine natural product dysiherbaine was accomplished. The key steps of the synthesis are an alkylation at the γ-carbon of a protected glutamate with a highly substituted pyran derived from mannose, which was followed by a ring-contraction cascade reaction, which simultaneously gave the tetrasubstituted carbon and the hexahydrofuro[3,2-b]pyran ring system of the natural product.
Population dynamics of mutualism and intraspecific density dependence: How θ-logistic density dependence affects mutualistic positive feedback

Abstract Mutualism describes the biological phenomenon where two or more species are reciprocally beneficial, regardless of their ecological intimacy or evolutionary history. Classic theory shows that mutualistic benefit must be relatively weak, or else it overpowers the stabilizing influence of intraspecific competition and leads to unrealistic, unbounded population growth. Interestingly, the conclusion that strong positive interactions lead to runaway population growth is strongly grounded in the behavior of a single model. This model—the Lotka–Volterra competition model with a sign change to generate mutualism rather than competition between species—assumes logistic growth of each species plus a linear interaction term to represent the mutualism. While it is commonly held that the linear interaction term is to blame for the model's unrealistic behavior, we show here that a linear mutualism added to a θ-logistic model of population growth can prevent unbounded growth. We find that when density dependence is decelerating, the benefit of mutualism at equilibrium is greater than when density dependence is accelerating. Although there is a greater benefit, however, decelerating density dependence tends to destabilize populations whereas accelerating density dependence is always stable. We interpret these findings tentatively, but with promise for the understanding of the population ecology of mutualism by generating several predictions relating growth rates of mutualist populations and the strength of mutualistic interaction.
Lamellipodium is a myosin-independent mechanosensor

The ability of adherent cells to sense changes in the mechanical properties of their extracellular environments is critical to numerous aspects of their physiology. It has been well documented that cell attachment and spreading are sensitive to substrate stiffness. Here, we demonstrate that this behavior is actually biphasic, with a transition that occurs around a Young's modulus of ∼7 kPa. Furthermore, we demonstrate that, contrary to established assumptions, this property is independent of myosin II activity. Rather, we find that cell spreading on soft substrates is inhibited due to reduced myosin-II independent nascent adhesion formation within the lamellipodium. Cells on soft substrates display normal leading-edge protrusion activity, but these protrusions are not stabilized due to impaired adhesion assembly. Enhancing integrin-ECM affinity through addition of Mn2+ recovers nascent adhesion assembly and cell spreading on soft substrates. Using a computational model to simulate nascent adhesion assembly, we find that biophysical properties of the integrin-ECM bond are optimized to stabilize interactions above a threshold matrix stiffness that is consistent with the experimental observations. Together, these results suggest that myosin II-independent forces in the lamellipodium are responsible for mechanosensation by regulating new adhesion assembly, which, in turn, directly controls cell spreading. This myosin II-independent mechanism of substrate stiffness sensing could potentially regulate a number of other stiffness-sensitive processes.
Colloidal Palladium Nanoparticles: Reduction of Pd(II) by H2; PdCoreAuShellAgShell Particles

Palladium colloid with a narrow particle size distribution is formed in the reduction of PdCl42- by hydrogen in aqueous solution, using sodium citrate as stabilizer. The absorption spectrum of the Pd particles depends on their content of chemisorbed hydrogen atoms. In the absence of hydrogen, the absorption maximum at 218 nm is present, which is expected from calculations. In the presence of hydrogen, the spectrum is flatter and peaks at 258 nm. Radiolytic methods are applied to prepare bimetallic PdcoreAushell and trimetallic PdcoreAushellAgshell particles, and the optical spectra of these structures are reported.
DIC-Mediated Coupling of Carboxylic Acids to (4R, 5S)-4-Methyl-5-Phenyl-2-Oxazolidinone

Abstract The use of diisopropylcarbodiimide as an agent to effect the coupling of carboxylic acids to Evans' chiral auxiliary (4R, 5S)-4-methyl-5-phenyl-2-oxazolidinone provides the corresponding acyl derivatives in good yields.
Synthesis of highly coherent SiGe and Si4Ge nanostructures by molecular beam epitaxy of H3SiGeH3 and Ge(SiH3)4

Stoichiometric SiGe and Si4Ge epitaxial films and coherent islands are created on Si(100) via thermal dehydrogenation of H3SiGeH3 and Ge(SiH3)4, respectively. The control of morphology and composition x of Si1-xGex nanostructures at the atomic level is achieved for the first time via CVD growth of single-source precursors containing precise atomic arrangements with direct Si−Ge bonds.
Intensity-based axial localization approaches for multifocal plane microscopy.

Multifocal plane microscopy (MUM) can be used to visualize biological samples in three dimensions over large axial depths and provides for the high axial localization accuracy that is needed in applications such as the three-dimensional tracking of single particles and super-resolution microscopy. This report analyzes the performance of intensity-based axial localization approaches as applied to MUM data using Fisher information calculations. In addition, a new non-parametric intensity-based axial location estimation method, Multi-Intensity Lookup Algorithm (MILA), is introduced that, unlike typical intensity-based methods that make use of a single intensity value per data image, utilizes multiple intensity values per data image in determining the axial location of a point source. MILA is shown to be robust against potential bias induced by differences in the sub-pixel location of the imaged point source. The method’s effectiveness on experimental data is also evaluated.
Studies Relevant to Ellagitannin Chemistry: Highly Diastereoselective Intramolecular Biaryl Coupling in Bis(iodotrimethoxybenzoyl) Hexopyranose Derivatives

Internal biaryl coupling reactions of carbohydrate derivatives carrying two 2-iodo-3,4,5-trimethoxybenzoyl groups under Ullmann conditions were investigated. With substituents at positions 2,3 or 4,6 of a d-glucopyranoside, 2,3 of a d-mannopyranoside, and 3,4 of a d-galactopyranoside, the coupling was found to proceed with a very high degree of stereoselectivity, leading exclusively to the (S)-epimer of the resulting hexamethoxydiphenoyl residue from the d-gluco and d-galacto substrates, and to the (R)-epimer from the d-manno substrate. With substituents at positions 2,4 of d-glucopyranose derivatives in the 1C4 conformation and at positions 5,6 of a d-glucofuranose derivative, the coupling proceeded efficiently but with modest stereoselectivity. Some deiodinated starting material was formed as a byproduct in all reactions. These results are relevant to ellagitannin chemistry in that they provide further understanding of the structural requirements for highly diastereoselective biaryl coupling within carb...
Multimodal perioperative pain protocol for Gynecologic Oncology laparotomy reduces length of hospital stay

Our primary objective was to evaluate the impact of a multimodal perioperative pain regimen on length of hospital stay for patients undergoing laparotomy with a gynecologic oncologist.
Synthesis of furano[2,3-c]-pyran-3-one and thieno[2,3-c]-pyran-3-one derivatives through the coupling of 3-alkynyl-2-heteroaromatic carboxaldehydes with Fischer carbene complexes

Abstract The coupling of Fischer carbene complexes with 3-alkynyl-2-heteroaromatic carboxaldehyde derivatives has been examined. The reaction affords pyrones fused to furans or thiophenes in a single step. The compounds are stable enough for isolation. If the carbene complex features a remote alkene substituent, a subsequent Diels–Alder reaction can occur.
Bioengineered intestinal muscularis complexes with long-term spontaneous and periodic contractions

Although critical for studies of gut motility and intestinal regeneration, the in vitro culture of intestinal muscularis with peristaltic function remains a significant challenge. Periodic contractions of intestinal muscularis result from the coordinated activity of smooth muscle cells (SMC), the enteric nervous system (ENS), and interstitial cells of Cajal (ICC). Reproducing this activity requires the preservation of all these cells in one system. Here we report the first serum-free culture methodology that consistently maintains spontaneous and periodic contractions of murine and human intestinal muscularis cells for months. In this system, SMC expressed the mature marker myosin heavy chain, and multipolar/dipolar ICC, uniaxonal/multipolar neurons and glial cells were present. Furthermore, drugs affecting neural signals, ICC or SMC altered the contractions. Combining this method with scaffolds, contracting cell sheets were formed with organized architecture. With the addition of intestinal epithelial cells, this platform enabled up to 11 types of cells from mucosa, muscularis and serosa to coexist and epithelial cells were stretched by the contracting muscularis cells. The method constitutes a powerful tool for mechanistic studies of gut motility disorders and the functional regeneration of the engineered intestine.
Syntheses, optical properties and electronic structures of copper(I) tantalates: Cu5Ta11O30 and Cu3Ta7O19

Abstract Two copper tantalates, Cu5Ta11O30 (1) and Cu3Ta7O19 (2), were synthesized by solid-state and flux synthetic methods, respectively. A synthetic route yielding 2 in high purity was found using a CuCl flux at 800oC and its structure was characterized using powder X-ray diffraction (XRD) data (P63/m (no. 176), Z=2, a=6.2278(1) A, and c=20.1467(3) A). The solid-state synthesis of 1 was performed using excess Cu2O that helped to facilitate the growth of single crystals and their characterization by XRD (P6¯2c (no. 190), Z=2, a=6.2252(1) A, and c=32.516(1) A). The atomic structures of both copper tantalates consist of alternating single and double layers of TaO7 pentagonal bipyramids that are bridged by a single layer of isolated TaO6 octahedra and linearly-coordinated Cu+. Measured optical bandgap sizes of ∼2.59 and ∼2.47 eV for 1 and 2 were located well within visible-light energies and were consistent with their orange–yellow colours. Each also exhibits optical absorption coefficients at the band edge of ∼700 and ∼275 cm−1, respectively, and which were significantly smaller than that for NaTaO3 of ∼1450 cm−1. Results of LMTO calculations indicate that their visible-light absorption is attributable mainly to indirect bandgap transitions between Cu 3d10 and Ta 5d0 orbitals within the TaO7 pentagonal bipyramids.
Imidoylketene: An ab Initio Study of Its Conformations and Reactions.

MP4(SDQ)/6-31G**//MP2/6-31G** calculations on the conformations of imidoylketene (1) as well as transition structures for several of its reactions are reported. Anti-Z-1 and anti-E-1 are of equal energy, while syn-Z-1 and syn-E-1 are respectively 2.0 and 0.5 kcal/mol higher. As the nitrogen analog of formylketene (2), the reactivity of 1 is modified from that of 2. While the nitrogen in 1 is more basic and nucleophilic than the oxygen in 2, greater resonance donation from the nitrogen decreases the electrophilicity of the ketene carbon in 1 relative to 2. Thus the barriers for the addition of water (6.3 kcal/mol) and of formaldehyde (10.6 kcal/mol) to 1 are very similar to those previously calculated for their respective additions to 2. Transition structures for the 1,3-hydrogen shifts of 3-amino-1,2-propadien-1-one (5a) and formylketene imine (6a) to give 1 were also located. The barriers to these reactions, (41.0 and 48.6 kcal/mol, respectively) are higher than those of the analogous reactions to form 2...
Preparation and spectroscopic properties of 3-acyl-1,3,4-oxadiazolines

1,3,4-Oxadiazolines I, in which substituent groups R1 through R4 may be varied through appropriate choice of precursor reactants, can be prepared in good yields and purity by convenient cyclizations of acyl-hydrazones with anhydrides. The reactions can be effectively monitored by salient changes in the infrared spectra. The oxadiazolines are stable materials and thus serve as suitable derivatives for the chemical characterization of such tuberculostatic Schiff bases as IIa-c.