Coulomb dissociation in relativistic heavy ion reactions

Targets of (\u2712)C, (\u2759)Co, (\u2789)Y, (\u27197)Au and (\u27238)U were bombarded by 2.1 GeV/A (\u271)H, (\u2712)C and (\u2720)Ne projectiles using the SuperHILAC and BEVATRON facilities at Lawrence Berkeley Laboratory (LBL). The beam flux was calculated by monitoring the decay of (\u2711)C produced from the (\u2712)C(projectile,projectile n)(\u2711)C reaction. Residual gamma-ray activity from the Co, Y, Au and U targets was collected in order to trace the decay of several reaction products. The experiment focused on the calculation of cross sections for the formation of products with one neutron removed from the various target nuclei. Corrections to the saturation activity of each product were made for detector efficiency, gamma-ray absorption in the target, gamma-ray branching, beam geometry and secondary reactions;These data are shown to be inconsistent with a geometrical form given by;(sigma) (PROPORTIONAL) (A(,p)(\u271/3) + A(,t)(\u271/3) - b);where b is a universal constant. In fact the data indicates the b = A(,t)(\u271/3). Instead the data can be fit quite well by a simple empirical relation,;(sigma)(,emp) = 12.0 mb A(,p)(\u271/3) A(,t)(\u271/3);It is demonstrated that an empirical fit which varies as A(,t)(\u271/3) is^also consistent with projectile fragmentation data measured by a^group at LBL. In addition these data are compared to a theoretical^prediction which is the sum of a renormalized Glauber term and a^term which represents the contribution due to coulomb or^electromagnetic dissociation (ED). The theoretical predictions are^quite low for the (\u2712)C projectile data and high for the (\u2720)Ne projectile^data. The systematic trends from the comparison seem to indicate^that theoretical prediction for the ED contribution is rising too fast;as a function of projectile for a given target;(\u271)DOE Report IS-T-1012. This work was performed under ContractNo. W-7405-Eng-82 with the U.S. Department of Energy

Risks to bees from dusts emitted at sowing of coated seeds: concerns, risk assessment and risk management

contribution to session V Honey bee poisoning incidents and monitoring scheme

Teegi: Tangible EEG Interface

We introduce Teegi, a Tangible ElectroEncephaloGraphy (EEG) Interface that enables novice users to get to know more about something as complex as brain signals, in an easy, en- gaging and informative way. To this end, we have designed a new system based on a unique combination of spatial aug- mented reality, tangible interaction and real-time neurotech- nologies. With Teegi, a user can visualize and analyze his or her own brain activity in real-time, on a tangible character that can be easily manipulated, and with which it is possible to interact. An exploration study has shown that interacting with Teegi seems to be easy, motivating, reliable and infor- mative. Overall, this suggests that Teegi is a promising and relevant training and mediation tool for the general public.Comment: to appear in UIST-ACM User Interface Software and Technology Symposium, Oct 2014, Honolulu, United State

Juvenile vervet monkeys rely on others when responding to danger

Funding: Open access funding provided by University of Lausanne. Funding was provided by FP7 Ideas: European Research Council, 283871, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, 310030_143359, PP00P3_170624, Branco Weiss Fellowship-Society in Science.Primate alarm calls are mainly hardwired but individuals need to adapt their calling behaviours according to the situation. Such learning necessitates recognising locally relevant dangers and may take place via their own experience or by observing others. To investigate monkeys alarm calling behaviour, we carried out a field experiment in which we exposed juvenile vervet monkeys to unfamiliar raptor models in the presence of audiences that differed in experience and reliability. We used audience age as a proxy for experience and relatedness as a proxy for reliability, while quantifying audience reactions to the models. We found a negative correlation between alarm call production and callers’ age. Adults never alarm called, compared to juveniles. We found no overall effect of audience composition and size, with juveniles calling more when with siblings than mothers or unrelated individuals. Finally, concerning audience reactions to the models, we observed juveniles remained silent with vigilant mothers and only alarm called with ignoring mothers, whereas we observed the opposite for siblings: juveniles remained silent with ignoring siblings and called with vigilant siblings. Despite the small sample size, juvenile vervet monkeys, confronted with unfamiliar and potentially dangerous raptors, seem to rely on others to decide whether to alarm call, demonstrating that the choice of the model may play an important key role in the ontogeny of primate alarm call behaviour.Publisher PDFPeer reviewe

A predictor-corrector method for the transient motion of a nonhomogeneous incompressible, viscous fluid

The system of partial differential equations which governs the motion of a Newtonian fluid has been known for over a century. Yet, due to the complexity of the equations, an analytical solution is known only for a few simple geometries or a few special cases such as very slow motion. No general analytical solution is known. The development of the digital computer has led to sophisticated numerical techniques for solving systems of partial differential equations. This paper develops a predictor- corrector numerical method which solves simultaneously the Navier- Stokes equation, the continuity equation, the incompressibility equation and the energy equation - -first law of thermodynamics - -for a nonhomogeneous, viscous fluid. As an example of the potential of this method, the problem of finding the transient flow from a density stratified reservoir is solved. In addition a FORTRAN IV listing for this problem is included

A platform for the discovery of new macrolide antibiotics.

The chemical modification of structurally complex fermentation products, a process known as semisynthesis, has been an important tool in the discovery and manufacture of antibiotics for the treatment of various infectious diseases. However, many of the therapeutics obtained in this way are no longer effective, because bacterial resistance to these compounds has developed. Here we present a practical, fully synthetic route to macrolide antibiotics by the convergent assembly of simple chemical building blocks, enabling the synthesis of diverse structures not accessible by traditional semisynthetic approaches. More than 300 new macrolide antibiotic candidates, as well as the clinical candidate solithromycin, have been synthesized using our convergent approach. Evaluation of these compounds against a panel of pathogenic bacteria revealed that the majority of these structures had antibiotic activity, some efficacious against strains resistant to macrolides in current use. The chemistry we describe here provides a platform for the discovery of new macrolide antibiotics and may also serve as the basis for their manufacture

A Quantum-Mechanical Equivalent-Photon Spectrum for Heavy-Ion Physics

In a previous paper, we calculated the fully quantum-mechanical cross section for electromagnetic excitation during peripheral heavy-ion collisions. Here, we examine the sensitivity of that cross section to the detailed structure of the projectile and target nuclei. At the transition energies relevant to nuclear physics, we find the cross section to be weakly dependent on the projectile charge radius, and to be sensitive to only the leading momentum-transfer dependence of the target transition form factors. We exploit these facts to derive a quantum-mechanical ``equivalent-photon spectrum'' valid in the long-wavelength limit. This improved spectrum includes the effects of projectile size, the finite longitudinal momentum transfer required by kinematics, and the response of the target nucleus to the off-shell photon.Comment: 19 pages, 5 figure

Soliton generation by internal tidal beams impinging on a pycnocline: laboratory experiments

In this paper, we present the first laboratory experiments that show the generation of internal solitary waves by the impingement of a quasi-two-dimensional internal wave beam on a pycnocline. These experiments were inspired by observations of internal solitary waves in the deep ocean from synthetic aperture radar (SAR) imagery, where this so-called mechanism of 'local generation' was argued to be at work, here in the form of internal tidal beams hitting the thermocline. Nonlinear processes involved here are found to be of two kinds. First, we observe the generation of a mean flow and higher harmonics at the location where the principal beam reflects from the surface and pycnocline; their characteristics are examined using particle image velocimetry (PIV) measurements. Second, we observe internal solitary waves that appear in the pycnocline, detected with ultrasonic probes; they are further characterized by a bulge in the frequency spectrum, distinct from the higher harmonics. Finally, the relevance of our results for understanding ocean observations is discussed

The Association of Maternal Obesity and Race with Pregnancy Weight Gain and Small for Gestational Age Infant Birth: The Effect of Prenatal Care

Objective: To examine the association of maternal obesity, race/ethnicity, and prenatal care on high gestational weight gain (GWG) and small for gestational age (SGA) infant birth. Methods: This was a retrospective cohort study of births included in the PRAMS Phase 8 dataset (2016-2017). The study population was 53,893 non-diabetic women with a singleton in-hospital birth between 37 and 42 weeks gestational age. Results: Only obese non-Hispanic white and Hispanic women showed a consistent decrease in adjusted odds of high GWG as prenatal care visit category increased. Only non-Hispanic white women showed a lower increase in adjusted odds of an SGA infant birth with more compared to intermediate prenatal care. Conclusions: The effectiveness of prenatal care in reducing high GWG varies by race for women with a BMI outside a healthy range. More prenatal care did not reduce SGA infant births amongst overweight or obese women. Policy implications: Interventions to improve prenatal care delivery for overweight or obese women should consider race