Yo no fumo

Victoria Rodrigo, PhD- Serie Leamos’ EditorProfessor of Spanish World Languages and Cultures DepartmentGeorgia State Universityhttps://scholarworks.gsu.edu/wcl_leamos/1035/thumbnail.jp

The Shallow Geological Model: mapping and monitoring the marine landscape

Managing our seas without a sound knowledge of the sea-bed environment and the processes that shape the sea-bed characteristics makes it difficult to conserve key areas, maintain biodiversity and economically develop our marine resources in an efficient and sustainable way. Recent developments in marine landscape mapping, visualisation techniques and instant data access provide timely, proven technologies that are now in widespread use

Are infestations of Cymomelanodactylus killing Acropora cytherea in the Chagos archipelago?

Associations between branching corals and infaunal crabs are well known, mostly due to the beneficial effects of Trapezia and Tetralia crabs in protecting host corals from crown-of-thorns starfish (e.g., Pratchett et al. 2000) and/or sedimentation (Stewart et al. 2006). These crabs are obligate associates of live corals and highly prevalent across suitable coral hosts, with 1–2 individuals per colony (Patton 1994). Cymo melanodactylus (Fig. 1) are also prevalent in branching corals, mostly Acropora, and are known to feed on live coral tissue, but are generally found in low abundance (<3 per colony) and do not significantly affect their host corals (e.g., Patton 1994). In the Chagos archipelago, however, infestations of Cymo melanodactylus were found on recently dead and dying colonies of Acropora cytherea

An early giant planet instability recorded in asteroidal meteorites

Giant planet migration appears widespread among planetary systems in our Galaxy. However, the timescales of this process, which reflect the underlying dynamical mechanisms, are not well constrained, even within the solar system. Since planetary migration scatters smaller bodies onto intersecting orbits, it would have resulted in an epoch of enhanced bombardment in the solar system's asteroid belt. To accurately and precisely quantify the timescales of migration, we interrogate thermochronologic data from asteroidal meteorites, which record the thermal imprint of energetic collisions. We present a database of 40K-40Ar system ages from chondrite meteorites and evaluate it with an asteroid-scale thermal code coupled to a Markov chain Monte Carlo inversion. Simulations require bombardment in order to reproduce the observed age distribution and identify a bombardment event beginning ~11 million years after the Sun formed. Our results associate a giant planet instability in our solar system with the dissipation of the gaseous protoplanetary disk.Comment: 24 pages, 4 figures, 2 tables, 10 extended data items (8 figures, 2 tables). Under review at Nature Astronom

Machine learning augmented diagnostic testing to identify sources of variability in test performance

Diagnostic tests which can detect pre-clinical or sub-clinical infection, are one of the most powerful tools in our armoury of weapons to control infectious diseases. Considerable effort has been therefore paid to improving diagnostic testing for human, plant and animal diseases, including strategies for targeting the use of diagnostic tests towards individuals who are more likely to be infected. Here, we follow other recent proposals to further refine this concept, by using machine learning to assess the situational risk under which a diagnostic test is applied to augment its interpretation . We develop this to predict the occurrence of breakdowns of cattle herds due to bovine tuberculosis, exploiting the availability of exceptionally detailed testing records. We show that, without compromising test specificity, test sensitivity can be improved so that the proportion of infected herds detected by the skin test, improves by over 16 percentage points. While many risk factors are associated with increased risk of becoming infected, of note are several factors which suggest that, in some herds there is a higher risk of infection going undetected, including effects that are correlated to the veterinary practice conducting the test, and number of livestock moved off the herd

Revision of the \u3cem\u3eMesobuthus caucasicus\u3c/em\u3e complex from Central Asia, with descriptions of six new species (Scorpiones: Buthidae)

A widespread Mesobuthus caucasicus complex, which includes some of the most common scorpions found from the Caucasus to China, is revised for the first time based on new extensive collections from Central Asia, using both morphological and DNA marker data. Mesobuthus caucasicus (Nordmann, 1840), s.str. is restricted to the Caucasus Mts. Four taxa are elevated to species rank: M. fuscus (Birula, 1897) (Tajikistan), M. intermedius (Birula, 1897) (Tajikistan), M. kaznakovi (Birula, 1904) (Tajikistan, Uzbekistan), and M. parthorum (Pocock, 1889) (Afghanistan, Iran, Turkmenistan). Six new species are described: M. brutus sp. n. (Iran), M. elenae sp. n. (Tajikistan, Uzbekistan), M. gorelovi sp. n. (Kazakhstan, Turkmenistan, Uzbekistan), M. kreuzbergi sp. n. (Tajikistan, Uzbekistan), M. mischi sp. n. (Afghanistan), and M. nenilini sp. n. (Uzbekistan). The most common species in Central Asia is a psammophilic Mesobuthus gorelovi sp. n., widespread through lowland sand deserts across Turkmenistan (Karakum), Uzbekistan (Kizylkum), and Kazakhstan (north to Baigakum and Moyinkum). A key to all studied species is provided. A DNA phylogeny based on COI and 16S rRNA markers is presented including nine Central Asian species (M. elenae sp. n., M. fuscus, M. gorelovi sp. n., M. intermedius, M. kaznakovi, M. kreuzbergi sp. n., M. mischi sp. n., M. nenilini sp. n., and M. parthorum) and M. caucasicus from Turkey. A deep phylogenetic diversity across Central Asia is revealed. Historical biogeographic scenarios for this scorpion group are discussed, including fragmentation in mountain valleys and expansion across sand deserts in Central Asia. The monotypic scorpion genus Afghanobuthus Lourenço, 2005 and its single species A. naumanni Lourenço, 2005, from Afghanistan, are demonstrated to be junior synonyms, respectively, of Mesobuthus Vachon, 1950, and M. parthorum (Pocock, 1889) from the same area

The Genetic Requirements for Fast and Slow Growth in Mycobacteria

Mycobacterium tuberculosis infects a third of the world's population. Primary tuberculosis involving active fast bacterial replication is often followed by asymptomatic latent tuberculosis, which is characterised by slow or non-replicating bacteria. Reactivation of the latent infection involving a switch back to active bacterial replication can lead to post-primary transmissible tuberculosis. Mycobacterial mechanisms involved in slow growth or switching growth rate provide rational targets for the development of new drugs against persistent mycobacterial infection. Using chemostat culture to control growth rate, we screened a transposon mutant library by Transposon site hybridization (TraSH) selection to define the genetic requirements for slow and fast growth of Mycobacterium bovis (BCG) and for the requirements of switching growth rate. We identified 84 genes that are exclusively required for slow growth (69 hours doubling time) and 256 genes required for switching from slow to fast growth. To validate these findings we performed experiments using individual M. tuberculosis and M. bovis BCG knock out mutants. We have demonstrated that growth rate control is a carefully orchestrated process which requires a distinct set of genes encoding several virulence determinants, gene regulators, and metabolic enzymes. The mce1 locus appears to be a component of the switch to slow growth rate, which is consistent with the proposed role in virulence of M. tuberculosis. These results suggest novel perspectives for unravelling the mechanisms involved in the switch between acute and persistent TB infections and provide a means to study aspects of this important phenomenon in vitro