cssi/SciSciGPT-SciSciNet huggingface dataset:
A new methodology for the synthesis of β-amino acids

A differentially functionalized succinic acid unit 6 undergoes alkylation with excellent regio- and high stereocontrol at the carbon α to the imide to furnish the alkylated product 7 in 60–83% yield. Selective removal of the imide provides 8 in 80–90% yields. Curtius rearrangement of 8 with retention of stereochemistry provides N-protected β-amino acids (9) in 70–83% yields. Alternatively, selective deprotection of the ester group followed by Curtius rearrangement provides isomeric β-amino acids 14a, 14b, and 14e in good yields. The methodology has been successfully applied to the synthesis of N-Boc-iturinic acid and 2-methyl-3-aminopropanoic acid, components of the antifungal peptide iturin and the cytotoxic depsipeptide cryptophycin respectively.
Time-Accurate Numerical Prediction of Free-Flight Aerodynamics of a Finned Projectile

This article describes a new multidisciplinary computational study undertaken to compute the flight trajectories and simultaneously predict the unsteady free-flight aerodynamics of a finned projectile configuration. Actual flight trajectories are computed using an advanced coupled computational fluid dynamics/rigid body dynamics technique in a body-fixed coordinate system. An advanced time-accurate Navier–Stokes computational technique has been used in computational fluid dynamics to compute the unsteady aerodynamics associated with the free flight of the finned projectile at supersonic speeds. Computed positions and orientations of the projectile have been compared with actual data measured from free-flight tests and are found to be generally in good agreement with the data. Predicted aerodynamics forces and moments also compare well with the forces and moments used in the 6 degree of freedom fits of the results of the same tests. Unsteady numerical results obtained from the coupled method show the flowfield, the aerodynamic coefficients, and the flight paths of the projectile.
Spinning dust emission: the effect of rotation around a non-principal axis

We investigate the rotational emission from dust grains that rotate around non-principal axes. We argue that in many phases of the interstellar medium, the smallest grains, which dominate spinning dust emission, are likely to have their nutation state (orientation of principal axes relative to the angular momentum vector) randomized during each thermal spike. We recompute the excitation and damping rates associated with rotational emission from the grain permanent dipole, grain–plasma interactions, infrared photon emission and collisions. The resulting spinning dust spectra generally show a shift towards higher emissivities and peak frequencies relative to previous calculations.
The Utilisation of Curative Healthcare in Mozambique: Does Income Matter?

In Mozambique, easily treatable diseases such as malaria, diarrhea, and respiratory infections contribute to a heavy burden of disease. Notwithstanding efforts by the Mozambican government to promote access to health care, many who could benefit from simple cost-effective health care services do not currently receive treatment. Moreover, it is known that the utilization of health services varies considerably across spatial domains and socio-economic groups. This paper is concerned with understanding the determinants of utilization of curative health services, paying particular attention to the role of income. It provides a broad analytical framework for analyzing both the binary decision to seek formal health care in the event of illness, and the multinomial choice of health care provider. The results show that income is not an important determinant of health care choices in Mozambique. Rather, other factors, in particular education and physical access, are more important. Moreover, unlike in some studies, own (time) price elasticity does not vary notably with income. At a methodological level, the analysis shows that the general conclusions are robust to a number of estimation issues that are rarely addressed explicitly in the analysis of health care choices, including sample selection, the potential endogeneity of consumption, and cluster-level unobservables. For the analysis of provider choice, the paper demonstrates the merits of a “flexible” behavioral model. In particular, the paper rejects some of the restrictions of the standard model of provider choice, and shows that both the level of the price elasticity and the extent to which the elasticity varies with income is sensitive to the empirical specification.
13 C- 18 O bonds in carbonate minerals: A new kind of paleothermometer

The abundance of the doubly substituted CO2 isotopologue, 13 C 18 O 16 O, in CO2 produced by phosphoric acid digestion of synthetic, inorganic calcite and natural, biogenic aragonite is proportional to the concentration of 13 C– 18 O bonds in reactant carbonate, and the concentration of these bonds is a function of the temperature of carbonate growth. This proportionality can be described between 1 and 50 � C by the function: D47 = 0.0592 AE 10 6 AE T � 2 � 0.02, where D47 is the enrichment, in per mil, of 13 C 18 O 16 Oi n CO 2 relative to the amount expected for a stochastic (random) distribution of isotopes among all CO2 isotopologues, and T is the temperature in Kelvin. This relationship can be used for a new kind of carbonate paleothermometry, where the temperature-dependent property of interest is the state of ordering of 13 C and 18 O in the carbonate lattice (i.e., bound together vs. separated into different CO3 2� units), and not the bulk d 18 Oo rd 13 C values. Current analytical methods limit precision of this thermometer to ca. ± 2 � C, 1r. A key feature of this thermometer is that it is thermodynamically based, like the traditional carbonate–water paleothermometer, and so is suitable for interpolation and even modest extrapolation, yet is rigorously independent of the d 18 O of water and d 13 C of DIC from which carbonate grew. Thus, this technique can be applied to parts of the geological record where the stable isotope compositions of waters are unknown. Moreover, simultaneous determinations of D47 and d 18 O for carbonates will constrain the d 18 O of water from which they grew.
The Hedonistic Paradox: Is Homo Economicus Happier?

The “Hedonistic Paradox” states that homo economicus, or someone who seeks happiness for him- or herself, will not find it, but the person who helps others will. This study examines two questions in connection with happiness and generosity. First, do more generous people, as identified in dictator experiments, report on average greater happiness, or subjective well-being (SWB), as measured by responses to various questionnaires? Second, if the answer is affirmative, what is the causal relationship between generosity and happiness? We find a favorable correlation between generosity and happiness (i.e., SWB is directly related to several measures of happiness and inversely related to unhappiness) and examine various possible explanations, including that material well-being causes both happiness and generosity. The evidence from this experiment, however, indicates that a tertiary personality variable, sometimes called psychological well-being, is the primary cause of both happiness and greater generosity. In contrast to field studies, the experimental method of this inquiry permits anonymity measures designed to minimize subject misrepresentation of intrinsic generosity (e.g., due to social approval motives) and of actual happiness (e.g., because of social desirability biases) and produces a rich data set with multiple measures of subjective, psychological and material well-being. The results of this and other studies raise the question of whether greater attention should be paid to the potential benefits (beyond solely the material ones) of policies that promote charitable donations, volunteerism, service education, and, more generally, community involvement, political action, and social institutions that foster psychological well-being.
Unemployment, Vacancies, Wages

Peter A. Diamond delivered his Prize Lecture on 8 December 2010 at Aula Magna, Stockholm University.
Tight Bounds for Hashing Block Sources

It is known that if a 2-universal hash function His applied to elements of a block source(X 1 ,...,X T ), where each item X i has enough min-entropy conditioned on the previous items, then the output distribution (H,H(X 1 ),...,H(X T )) will be "close" to the uniform distribution. We provide improved bounds on how much min-entropy per item is required for this to hold, both when we ask that the output be close to uniform in statistical distance and when we only ask that it be statistically close to a distribution with small collision probability. In both cases, we reduce the dependence of the min-entropy on the number Tof items from 2logTin previous work to logT, which we show to be optimal. This leads to corresponding improvements to the recent results of Mitzenmacher and Vadhan (SODA `08) on the analysis of hashing-based algorithms and data structures when the data items come from a block source.
Denial of Treatment to Obese Patients-the Wrong Policy on Personal Responsibility for Health.

In many countries around the world, including Iran, obesity is reaching epidemic proportions. Doctors have recently taken, or expressed support for, an extreme ‘personal responsibility for health’ policy against obesity: refusing services to obese patients. This policy may initially seem to improve patients’ incentives to fight obesity. But turning access to medical services into a benefit dependent on health improvement is bad policy. It conditions the very aid that patients need in order to become healthier on success in becoming healthier. Whatever else we may think of personal responsibility for health policies, this particular one is absurd. Unfortunately, quite a few personal responsibility for health policies use similar absurd conditioning. They mistakenly use as ‘carrots’ or ‘sticks’ for adherence the basic means to the same health outcomes that they seek to promote. This perspective proposes the following rule of thumb: any conditional incentive for healthy choice should be in a currency other than the basic means to that healthy choice.
CONSUMPTION AND SAVING OVER THE LIFE CYCLE: HOW IMPORTANT ARE CONSUMER DURABLES?

In this paper we investigate whether a standard life-cycle model in which households purchase nondurable consumption and consumer durables and face idiosyncratic income and mortality risk as well as endogenous borrowing constraints can account for two key patterns of consumption and asset holdings over the life cycle. First, consumption expenditures on both durable and nondurable goods are hump-shaped. Second, young households keep very few liquid assets and hold most of their wealth in consumer durables. In our model durables play a dual role: they both provide consumption services and act as collateral for loans. A plausibly parameterized version of the model predicts that the interaction of consumer durables and endogenous borrowing constraints induces durables accumulation early in life and higher consumption of nondurables and accumulation of financial assets later in the life cycle, of an order of magnitude consistent with observed data.
Jordan Blocks of Richardson Classes in the Classical Groups and the Bala-Carter Theorem #

This article provides new, relatively simple proofs of some important results about unipotent classes in simple linear algebraic groups. We derive the formula for the Jordan blocks of the Richardson class of a parabolic subgroup of a classical group. This result was originally due to Spaltenstein. Secondly, we derive the description of the natural partial order of unipotent classes in the general linear group in terms of their Jordan blocks. This result was originally due to Gerstenhaber. Finally, we obtain a proof of the Bala-Carter Theorem, which holds even in certain bad characteristics. This proof requires the prior knowledge of the number of unipotent classes, unlike the original proofs due to Bala, Carter and Pommerening.
Theoretical progress for the associated production of a Higgs boson with heavy quarks at hadron colliders

The production of a Higgs boson in association with a pair of $t\bar{t}$ or $b\bar{b}$ quarks plays a very important role at both the Tevatron and the Large Hadron Collider. The theoretical prediction of the corresponding cross sections has been improved by including the complete next-to-leading order QCD corrections. After a brief introduction, we review the results obtained for both the Tevatron and the Large Hadron Collider.
Price prediction strategies for market-based scheduling

In a market-based scheduling mechanism, the allocation of time-specific resources to tasks is governed by a competitive bidding process. Agents bidding for multiple, separately allocated time slots face the risk that they will succeed in obtaining only part of their requirement, incurring expenses for potentially worthless slots. We investigate the use of price prediction strategies to manage such risk. Given an uncertain price forecast, agents follow simple rules for choosing whether and on which time slots to bid. We find that employing price predictions can indeed improve performance over a straightforward baseline in some settings. Using an empirical game-theoretic methodology, we establish Nash equilibrium profiles for restricted strategy sets. This allows us to confirm the stability of price-predicting strategies, and measure overall efficiency. We further experiment with variant strategies to analyze the source of prediction's power, demonstrate the existence of self-confirming predictions, and compare the performance of alternative prediction methods.
Enhanced constructs for perceptual stimuli and behavioral combination in reactive systems

A new approach is presented that aids in the specification of behaviors in a reactive architecture by establishing the value of categorizing motor schemas in four distinct classes, based in part upon the perceptual features which drive them. One of these classes encompasses much of the prior work in guidance behaviors, and here we show in simulation how valuable such behaviors are in minimizing difficulties during the parameterization process of other behaviors. Guidelines for schema gains are derived from basic principles for each of the four classes, and notional concepts of GUI interfaces are provided that take advantage of the guidelines. Although some of these issues have been addressed in other ways, the approach described here focuses on computationally efficient mechanisms that work in the true spirit of reactive control and can complement learning methods and hybrid architectures in general.
Interlayer transport in disordered semiconductor electron bilayers

We study the effects of disorder on the interlayer transport properties of disordered semiconductor bilayers by performing self-consistent quantum transport calculations. We find that the addition of material disorder to the system affects the interlayer interactions leading to significant deviations in the interlayer transfer characteristics. In particular, we find that disorder decreases and broadens the tunneling peak, effectively reducing the interacting system to a non-interacting system. Our results suggest that the experimental observation of exchange-enhanced interlayer transport in semiconductor bilayers requires materials with mean free paths larger than the spatial extent of the system.