What went wrong with: "The Interaction of Neutrons With 7Be: "Lack of Standard Nuclear Physics Solution to the "Primordial 7Li Problem"", by M. Gai [arXiv:1812.09914v1]?

We comment here on results of the project aimed at measuring the 7Be(n,x) reactions at SARAF, Israel, in 2016, posted by M. Gai in [arXiv:1812.09914v1] without the knowledge of parts of the collaboration and against the explicit veto of the collaborators and the administration of the Paul Scherrer Institut, Switzerland. We address both the experimental shortcomings and the drawbacks in project conduction. M. Gais preprint is labeled as "on behalf of the SARAF Israel-US-Switzerland Collaboration", the author list is given as a reference to another unpublished contribution (cited as [27]) to the NPA8 conference in June 2017 in Catania). However, M. Gai did never have the right to report on unpublished proprietary data of the entire collaboration, and he was not authorized to act "on behalf of the collaboration". The contribution is declared as "accepted for publication", but in fact was retracted during the refereeing process. After several careful data evaluations, we have to state that the results of these measurements are not trustworthy and neither the given experimental data basis nor the corresponding data analysis can be improved further. Therefore, we requested to retract the posting immediately [arXiv:1904.03023]. We have to emphasize that, in our opinion, arXiv is not the appropriate platform for handling frictions in a collaboration. These problems should have been solved internally before publishing. Unfortunately, with his single-handed posting against the explicit disagreement of parts of the collaboration, M. Gai did not leave another possibility. With the present article, we expressed all our concerns and objections and we consider herewith the public discussion of this issue as closed.Comment: arXiv admin note: This version has been removed by arXiv administrators due to copyright infringemen

Uncovering the Role of Propagule Pressure in Determining Establishment Success Using a Synthetic Biology Approach

The spread of invasive species poses a major ecological and economical threat. Consequently there are ongoing efforts to develop a generalizable mechanism to predict establishment success of non-native species. One proposed mechanism to predict establishment success is propagule pressure, which is defined as the number of individuals introduced at a given time. Although some studies have demonstrated a positive correlation between propagule pressure and establishment success, others have not, and the effect of propagule pressure on establishment success remains unclear. To address this challenge, a strain of bacteria engineered with an Allee effect, a growth dynamic that is often associated with establishing species, was used. The timing between successive introduction events that resulted in establishment success was measured. It was observed that if the time between two introduction events was sufficiently long, growth did not occur. By manipulating the growth rate of the bacteria, it was shown that that the minimal time between the two introduction events that resulted in growth was constrained as growth rate decreased. Moreover, it was concluded that asymmetry in the density of bacteria introduced in the introduction events increased the maximum time between introduction events that resulted in growth. These results help to remedy conflicting data in the literature by identifying conditions where propagule pressure has, and does not have, a positive impact on establishment success. These findings can have major implications in understanding and predicting the unique population dynamics of invasive species

Sudbury project (University of Muenster-Ontario Geological Survey): Sr-Nd in heterolithic breccias and gabbroic dikes

One major objective of our Sudbury project was to define origin and age of the huge breccia units below and above the Sudbury Igneous Complex (SIC). The heterolithic Footwall Breccia (FB) represents a part of the uplifted crater floor. It contains subrounded fragments up to several meters in size and lithic fragments with shock features (greater than 10 GPa) embedded into a fine- to medium-grained matrix. Epsilon(sub Nd)-epsilon(sub Sr) relationships point to almost exclusively parautochthonous precursor lithologies. The different textures of the matrix reflect the metamorphic history of the breccia layer; thermal annealing by the overlying hot impact melt sheet (SIC) at temperatures greater than 1000 C resulted in melting of the fine crushed material, followed by an episode of metasomatic K-feldspar growth and, finally, formation of low-grade minerals such as actinolite and chlorite. Isotope relationships in the Onaping breccias (Gray and Green Member) are much more complex. All attempts to date the breccia formation failed: Zircons are entirely derived from country rocks and lack the pronounced Pb loss caused by the heat of the slowly cooling impact melt sheet (SIC). Rb-Sr techniques using either lithic fragments of different shock stages or the thin slab method, set time limits for the apparently pervasive alkali mobility in these suevitic breccias. The data array and the intercept in the plots point to a major Rb-Sr fractionation around 1.54 Ga ago. This model age is in the same range as the age obtained for the metasomatic matrix of the FB. Rb-Sr dating of a shock event in impact-related breccias seems to be possible only if their matrix had suffered total melting by the hot melt sheet (FB) or if they contain a high fraction of impact melt (suevitic Onaping breccias), whereas the degree of shock metamorphism in rock or lithic fragments plays a minor role. In the Sudbury case, however, the impact melt in the seuvitic breccias is devitrified and recrystallized, which changed Rb/Sr ratios quite drastically. Therefore, the Onaping breccias give only age limits for alteration and low-grade metamorphism. The Sm-Nd system was not reset during the Sudbury event; clasts as well as the matrix in the FB and in the Onaping breccias show preimpact 'Archean' Nd isotope signatures