Abstract
We study a recent recruitment drive for public sector positions in Mexico. Different salaries were announced randomly across recruitment sites, and job offers were subsequently randomized. ...Screening relied on exams designed to measure applicants’ intellectual ability, personality, and motivation. This allows the first experimental estimates of (1) the role of financial incentives in attracting a larger and more qualified pool of applicants, (2) the elasticity of the labor supply facing the employer, and (3) the role of job attributes (distance, attractiveness of the municipal environment) in helping fill vacancies, as well as the role of wages in helping fill positions in less attractive municipalities. A theoretical model of job applications and acceptance guides the empirical inquiry. We find that higher wages attract more able applicants as measured by their IQ, personality, and proclivity toward public sector work—that is, we find no evidence of adverse selection effects on motivation; higher wage offers also increased acceptance rates, implying a labor supply elasticity of around 2 and some degree of monopsony power. Distance and worse municipal characteristics strongly decrease acceptance rates, but higher wages help bridge the recruitment gap in worse municipalities.
Bacterial dysbiosis accompanies carcinogenesis in malignancies such as colon and liver cancer, and has recently been implicated in the pathogenesis of pancreatic ductal adenocarcinoma (PDA)
. ...However, the mycobiome has not been clearly implicated in tumorigenesis. Here we show that fungi migrate from the gut lumen to the pancreas, and that this is implicated in the pathogenesis of PDA. PDA tumours in humans and mouse models of this cancer displayed an increase in fungi of about 3,000-fold compared to normal pancreatic tissue. The composition of the mycobiome of PDA tumours was distinct from that of the gut or normal pancreas on the basis of alpha- and beta-diversity indices. Specifically, the fungal community that infiltrated PDA tumours was markedly enriched for Malassezia spp. in both mice and humans. Ablation of the mycobiome was protective against tumour growth in slowly progressive and invasive models of PDA, and repopulation with a Malassezia species-but not species in the genera Candida, Saccharomyces or Aspergillus-accelerated oncogenesis. We also discovered that ligation of mannose-binding lectin (MBL), which binds to glycans of the fungal wall to activate the complement cascade, was required for oncogenic progression, whereas deletion of MBL or C3 in the extratumoral compartment-or knockdown of C3aR in tumour cells-were both protective against tumour growth. In addition, reprogramming of the mycobiome did not alter the progression of PDA in Mbl- (also known as Mbl2) or C3-deficient mice. Collectively, our work shows that pathogenic fungi promote PDA by driving the complement cascade through the activation of MBL.
Central regulation of food intake is a key mechanism contributing to energy homeostasis. Many neural circuits that are thought to orchestrate feeding behavior overlap with the brain’s reward ...circuitry both anatomically and functionally. Manipulation of numerous neural pathways can simultaneously influence food intake and reward. Two key systems underlying these processes—those controlling homeostatic and hedonic feeding—are often treated as independent. Homeostatic feeding is necessary for basic metabolic processes and survival, while hedonic feeding is driven by sensory perception or pleasure. Despite this distinction, their functional and anatomical overlap implies considerable interaction that is often overlooked. Here, we argue that the neurocircuits controlling homeostatic feeding and hedonic feeding are not completely dissociable given the current data and urge researchers to assess behaviors extending beyond food intake in investigations of the neural control of feeding.
Rossi and Stuber discuss the entangled neurocircuitry that governs feeding and reward. Using insights from recently developed molecular and genetic tools, the authors argue that homeostatic feeding and hedonic feeding are highly interrelated and urge investigators to measure more than food intake when probing neuronal control of feeding.
OBJECTIVE:To review the literature concerning the efficacy of early ultrasonography (at 11–14 weeks of gestation) to identify fetal malformations.
DATA SOURCES:A search in PubMed, MEDLINE, Embase, ...Cochrane Library, and ClinicalTrials.gov was performed (January 2000 to December 2012). Keywords werefetal anatomy, fetal echocardiography, nuchal translucency, fetal structural anomalies, fetal malformations, prenatal diagnosis, prenatal screening, and first-trimester ultrasonography.
METHODS OF STUDY SELECTION:Inclusion criteria werefetal anatomy examination at early ultrasonography and diagnosis of fetal malformations confirmed by postnatal or postmortem examination. Data abstracted weresample size, location of structural defect, ultrasound modality, presence of multiple defects, and study population. Pooled detection rate was calculated for each malformation and compared with χ. Differences were considered statistically significant if P<.05.
TABULATION, INTEGRATION, AND RESULTS:From 1,203 articles, 19 were included. Overall, we pooled 78,002 fetuses undergoing ultrasonography at 11–14 weeks, of which 996 were malformed, leading to prevalence of malformation of 12 per 1,000. The overall detection rate was 472 of 957 (51%). The highest detection rate was achieved for neck anomalies (92%), whereas limbs (34%), face (34%), and genitourinary anomalies (34%) were associated with the lowest detection rate. At 14 weeks of gestation or less, fetal echocardiography detected 53% of congenital heart disease compared with 43% by complete scan (P=.040). The use of Doppler did not improve the detection rate for congenital heart defects (52% compared with 44%, respectively; P=.11). Multiple defects were identified more frequently than isolated malformations (60% compared with 44%; P=.005). The detection rate was higher combining transabdominal and transvaginal techniques (62%) than either abdominal (51%) or transvaginal (34%; P<.001). Detection rate was higher in women at high risk (65%) than unselected population (50% P=.001).
CONCLUSION:Because of the natural history of fetal defects and the late development of some organ systems, a number of fetal malformations remain undetected by early ultrasonography.
The photoactivation of electron donor‐acceptor complexes has emerged as a sustainable, selective and versatile strategy for the generation of radical species. Electron donor‐acceptor (EDA) ...complexation, however, imposes electronic constraints on the donor and acceptor components and this can limit the range of radicals that can be generated using the approach. New EDA complexation strategies exploiting sulfonium salts allow radicals to be generated from native functionality. For example, aryl sulfonium salts, formed by the activation of arenes, can serve as the acceptor components in EDA complexes due to their electron‐deficient nature. This “sulfonium tag” approach relaxes the electronic constraints on the parent substrate and dramatically expands the range of radicals that can be generated using EDA complexation. In this review, these new applications of sulfonium salts will be introduced and the areas of chemical space rendered accessible through this innovation will be highlighted.
Photoactivation of electron donor‐acceptor (EDA) complexes is a sustainable, selective and versatile strategy for the generation of radicals. Sulfonium salt acceptors promise to dramatically expand the range of radicals that can be generated and exploited using EDA chemistry; the use of readily installed “sulfonium tags” relaxes the electronic constraints typically imposed on the parent substrate by an EDA complexation approach.
In this paper we present a new adaptive two-stage algorithm for solving elliptic partial differential equations via a radial basis function collocation method. Our adaptive meshless scheme is based ...at first on the use of a leave-one-out cross validation technique, and then on a residual subsampling method. Each of phases is characterized by different error indicators and refinement strategies. The combination of these computational approaches allows us to detect the areas that need to be refined, also including the chance to further add or remove adaptively any points. The resulting algorithm turns out to be flexible and effective through a good interaction between error indicators and refinement procedures. Several numerical experiments support our study by illustrating the performance of our two-stage scheme. Finally, the latter is also compared with an efficient adaptive finite element method.
We show that continuous quantum nondemolition (QND) measurement of an atomic ensemble is able to improve the precision of frequency estimation even in the presence of independent dephasing acting on ...each atom. We numerically simulate the dynamics of an ensemble with up to N=150 atoms initially prepared in a (classical) spin coherent state, and we show that, thanks to the spin squeezing dynamically generated by the measurement, the information obtainable from the continuous photocurrent scales superclassically with respect to the number of atoms N. We provide evidence that such superclassical scaling holds for different values of dephasing and monitoring efficiency. We moreover calculate the extra information obtainable via a final strong measurement on the conditional states generated during the dynamics and show that the corresponding ultimate limit is nearly achieved via a projective measurement of the spin-squeezed collective spin operator. We also briefly discuss the difference between our protocol and standard estimation schemes, where the state preparation time is neglected.
A strategy for the synthesis of medium‐sized lactones and lactams from linear precursors is described in which an amine acts as an internal nucleophilic catalyst to facilitate a novel ...cyclisation/ring expansion cascade sequence. This method obviates the need for the high‐dilution conditions usually associated with medium‐ring cyclisation protocols, as the reactions operate exclusively via kinetically favourable “normal”‐sized cyclic transition states. This same feature also enables biaryl‐containing medium‐sized rings to be prepared with complete atroposelectivity by point‐to‐axial chirality transfer.
Two‐step process: A strategy for the synthesis of medium‐sized lactones and lactams from linear precursors is described in which an amine acts as an internal nucleophilic catalyst to facilitate a cyclisation/ring expansion cascade. This method obviates the need for high‐dilution conditions and enables medium‐sized ring biaryl scaffolds to be prepared with full control of atroposelectivity by point‐to‐axial chirality transfer.
In this paper we consider the problem of finding an optimal value of the shape parameter in radial basis function interpolation. In particular, we propose the use of a leave-one-out cross validation ...(LOOCV) technique combined with univariate global optimization methods, which involve strategies of global optimization with pessimistic improvement (GOPI) and global optimization with optimistic improvement (GOOI). This choice is carried out to overcome serious issues of commonly used optimization routines that sometimes result in shape parameter values are not globally optimal. New locally-biased versions of geometric and information Lipschitz global optimization algorithms are presented. Numerical experiments and applications to real-world problems show a promising performance and efficacy of the new algorithms, called LOOCV-GOPI and LOOCV-GOOI, in comparison with their direct competitors.
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