Two Algebraic Process Semantics for Contextual Nets

We show that the so-called 'Petri nets are monoids' approach initiated by Meseguer and Montanari can be extended from ordinary place/transition Petri nets to contextual nets by considering suitable non-free monoids of places. The algebraic characterizations of net concurrent computations we provide cover both the collective and the individual token philosophy, uniformly along the two interpretations, and coincide with the classical proposals for place/transition Petri nets in the absence of read-arcs

Creatine and entrepreneurship

Creatine is a nitrogenous organic acid which supplies energy to body cells and enhances physical performance. Using the Young Finns Study combined with the Finnish Linked employer-employee data we show that quantities of creatine measured in 1980 prior to labour market entry affect entrepreneurial success as measured by capital income accumulation over the period 1993–2010 (in particular for females). However, we do not find evidence that creatine affects the propensity to become an entrepreneur. Our study contributes to the emerging literature on biomarkers and entrepreneurship

Using functional near-infrared spectroscopy to assess social information processing in poor urban Bangladeshi infants and toddlers

Children living in low resource settings are at risk for failing to reach their developmental potential. While the behavioral outcomes of growing up in such settings are well-known, the neural mechanisms underpinning poor outcomes have not been well elucidated, particularly in the context of low- and middle-income countries. In this study, we measure brain metabolic responses to social and non-social stimuli in a cohort of 6- and 36-month-old Bangladeshi children. Study participants in both cohorts lived in an urban slum and were exposed to a broad range of adversity early in life including extreme poverty, malnutrition,, recurrent infections, and low maternal education. We observed brain regions that responded selectively to social stimuli in both ages indicating that these specialized brain responses are online from an early age. We additionally show that the magnitude of the socially selective response is related to maternal education, maternal stress, and the caregiving environment. Ultimately our results suggest that a variety of psychosocial hazards have a measurable relationship with the developing social brain. This article is protected by copyright. All rights reserved. [Abstract copyright: This article is protected by copyright. All rights reserved.

Exclusive measurements of quasi-free proton scattering reactions in inverse and complete kinematics

Quasi-free scattering reactions of the type (p, 2p) were measured for the first time exclusively in complete and inverse kinematics, using a 12C beam at an energy of ~400 MeV/u as a benchmark. This new technique has been developed to study the single-particle structure of exotic nuclei in experiments with radioactive-ion beams. The outgoing pair of protons and the fragments were measured simultaneously, enabling an unambiguous identification of the reaction channels and a redundant measurement of the kinematic observables. Both valence and deeply-bound nucleon orbits are probed, including those leading to unbound states of the daughter nucleus. Exclusive (p, 2p) cross sections of 15.8(18) mb, 1.9(2) mb and 1.5(2) mb to the low-lying 0p-hole states overlapping with the ground state (3/2-) and with the bound excited states of 11B at 2.125 MeV (1/2-) and 5.02 MeV (3/2-), respectively, were determined via γ-ray spectroscopy. Particle-unstable deep-hole states, corresponding to proton removal from the 0s-orbital, were studied via the invariant-mass technique. Cross sections and momentum distributions were extracted and compared to theoretical calculations employing the eikonal formalism. The obtained results are in a good agreement with this theory and with direct-kinematics experiments. The dependence of the proton-proton scattering kinematics on the internal momentum of the struck proton and on its separation energy was investigated for the first time in inverse kinematics employing a large-acceptance measurement

Quasi-free neutron and proton knockout reactions from light nuclei in a wide neutron-to-proton asymmetry range

The quasi-free scattering reactions 11C(p,2p) and 10,11,12C(p,pn) have been studied in inverse kinematics at beam energies of 300–400 MeV/u at the R3B-LAND setup. The outgoing proton-proton and proton-neutron pairs were detected in coincidence with the reaction fragments in kinematically complete measurements. The efficiency to detect these pairs has been obtained from GEANT4 simulations which were tested using the 12C(p,2p) and 12C(p,pn) reactions. Experimental cross sections and momentum distributions have been obtained and compared to DWIA calculations based on eikonal theory. The new results reported here are combined with previously published cross sections for quasi-free scattering from oxygen and nitrogen isotopes and together they enable a systematic study of the reduction of single-particle strength compared to predictions of the shell model over a wide neutron-to-proton asymmetry range. The combined reduction factors show a weak or no dependence on isospin asymmetry, in contrast to the strong dependency reported in nucleon-removal reactions induced by nuclear targets at lower energies. However, the reduction factors for (p,2p) are found to be 'significantly smaller than for (p,pn) reactions for all investigated nuclei.German Federal Ministry of Education and Research | Ref. BMBF 05P2015RDFN1German Federal Ministry of Education and Research | Ref. 05P15WOFNAEuropean Commission | Ref. FP7, ENSAR, n. 262010Comisión Interministerial de Ciencia y Tecnología (CICYT) | Ref. FPA2012-32443Comisión Interministerial de Ciencia y Tecnología (CICYT) | Ref. FPA2015-64969-07387Comisión Interministerial de Ciencia y Tecnología (CICYT) | Ref. FPA2015-69640-C2-1-PSwedish Research Council | Ref. 621-2011-5324National Science Foundation, EE. UU. | Ref. n. 1415656Department of Energy, EE. UU. | Ref. n. DE-FG02-08ER41533Fundação para a Ciência e a Tecnologia | Ref. PTDC/FIS/ 103902/200