Real-time setup to measure radon emission during rock deformation. Implications for geochemical surveillance

Laboratory experiments can represent a valid approach to unravel the complex interplay between the geochemical behaviour of radon and rock deformation mechanisms. In light of this, we present a new real-time experimental setup for analysing in continuum the alpha-emitting 222Rn and 220Rn daughters over variable stress–strain regimes. The most innovative segment of this setup consists of the radon accumulation chamber obtained from a tough and durable material that can host large cylindrical rock samples. The accumulation chamber is connected, in a closed-loop configuration, to a gas-drying unit and to a RAD7 radon monitor. A recirculating pump moves the gas from the rock sample to a solid-state detector for alpha counting of radon and thoron progeny. The measured radon signal is enhanced by surrounding the accumulation chamber with a digitally controlled heating belt. As the temperature is increased, the number of effective collisions of radon atoms increases favouring the diffusion of radon through the material and reducing the analytical uncertainty. The accumulation chamber containing the sample is then placed into a uniaxial testing apparatus where the axial deformation is measured throughout a linear variable displacement transducer. A dedicated software allows obtaining a variety of stress–strain regimes from fast deformation rates to long-term creep tests. Experiments conducted with this new real-time setup have important ramifications for the interpretation of geochemical anomalies recorded prior to volcanic eruptions or earthquakes

Innovazione tecnologica e offerta di skills:una simulazione

In this paper a dynamic stochastic model is used to simulate the matching process between skills demand and supply in a segmented labor market of a typical developing area where labor market frictions are pervasive. We address the issue of the emergence of a “bad” outcome i.e. equilibrium towards the low level of development, given adverse initial conditions. In a second step we discuss the sensitivity of the endogenous dynamics to parameters changes due to policy/institutional reforms that change the expectations of the economic agents.labor market frictions, matching process, simulation

A smart tablet application to quantitatively assess the dominant hand dexterity

Background and objective: The Nine-Hole Peg Test (NHPT) is the most used test to assess hand dexterity in clinical practice and is considered the gold standard but only evaluates the time needed to complete the task. The aim of this work is to describe a graphic test on a smart tablet to assess in a quantitative as well qualitative way the dominant hand dexterity and to validate it in a cohort of neurological subjects and healthy controls. Methods: The task consists in asking the subject to connect with a graphic line the start and the end point of a pre-defined path, with two different widths, in the most precise and fastest way possible. The path is constituted by a ‘meander’ and a ‘spiral’ part. The subjects perform the task on a smart tablet with a capacitive pen four times. The three parameters of interest considered at each trial are the execution time, length path, and number of interactions with the border. The app automatically computes these three parameters and stores the completed test files. The results of the digital graphic test are compared to the NHPT results. Healthy and pathological subjects are compared to each other, and performances obtained in different repetitions are compared to assess the learning effect in each population. Results: 53 subjects with a definitive diagnosis of neurodegenerative/genetic neurological disorders (34 men, mean age 59.1 ± 16.1) and 78 healthy controls (33 men, mean age 42.5 ± 16.3) were recruited. Among the pathological subjects, 31 also performed the NHPT. The graphic test clearly distinguish between the two populations for all parameters of interest. Moreover, compared to the gold standard NHPT, time has a moderate positive correlation (r = 0.57, p ≤ 0.001), whereas interactions and length have a strong positive correlation (r = 0.81, p ≤ 0.001) and (r = 0.69, p ≤ 0.001), respectively. Conclusions: The proposed digital test can measure in an accurate, quantitative and qualitative way dominant hand disability and can result more informative with respect to the gold standard NHPT. In homogeneous cohort of subjects (for example affected by multiple sclerosis or Parkinson disease), the digital test can be used as an outcome measure in clinical trials as well as a tool for monitoring disease progression at the dominant hand level

Slaves, Soldiers, Citizens: African American Artifacts of the Civil War Era

Based on the exhibit Slaves, Soldiers, Citizens: African American Artifacts of the Civil War Era, this book provides the full experience of the exhibit, which was on display in Special Collections at Musselman Library November 2012- December 2013. It also includes several student essays based on specific artifacts that were part of the exhibit. Table of Contents: Introduction Angelo Scarlato, Lauren Roedner ’13 & Scott Hancock Slave Collars & Runaways: Punishment for Rebellious Slaves Jordan Cinderich ’14 Chancery Sale Poster & Auctioneer’s Coin: The Lucrative Business of Slavery Tricia Runzel ’13 Isaac J. Winters: An African American Soldier from Pennsylvania Who Fought at Petersburg Avery Lentz ’14 Basil Biggs: A Prominent African American in Gettysburg after the Battle Lauren Roedner ’13 Linton Ingram: A Former Slave Who Became a Notable African American Educator in Georgia Brian Johnson & Lincoln Fitch ’14 Uncle Tom’s Cabin Theatre Poster: Racism in Post-Emancipation Entertainment Michelle Seabrook ’13 Essay Bibliographies Grand Army of the Republic Exhibit Inventory Acknowledgmentshttps://cupola.gettysburg.edu/libexhibits/1001/thumbnail.jp

Feeling the heat: The campylobacter jejuni HrcA transcriptional repressor is an intrinsic protein thermosensor

The heat-shock response, a universal protective mechanism consisting of a transcriptional reprogramming of the cellular transcriptome, results in the accumulation of proteins which coun-teract the deleterious effects of heat-stress on cellular polypeptides. To quickly respond to thermal stress and trigger the heat-shock response, bacteria rely on different mechanisms to detect temperature variations, which can involve nearly all classes of biological molecules. In Campylobacter jejuni the response to heat-shock is transcriptionally controlled by a regulatory circuit involving two re-pressors, HspR and HrcA. In the present work we show that the heat-shock repressor HrcA acts as an intrinsic protein thermometer. We report that a temperature upshift up to 42°C negatively affects HrcA DNA-binding activity to a target promoter, a condition required for de-repression of regu-lated genes. Furthermore, we show that this impairment of HrcA binding at 42°C is irreversible in vitro, as DNA-binding was still not restored by reversing the incubation temperature to 37°C. On the other hand, we demonstrate that the DNA-binding activity of HspR, which controls, in combi-nation with HrcA, the transcription of chaperones’ genes, is unaffected by heat-stress up to 45°C, portraying this master repressor as a rather stable protein. Additionally, we show that HrcA binding activity is enhanced by the chaperonin GroE, upon direct protein–protein interaction. In conclu-sion, the results presented in this work establish HrcA as a novel example of intrinsic heat-sensing transcriptional regulator, whose DNA-binding activity is positively modulated by the GroE chap-eronin

Validation of a graphic test to quantitatively assess the dominant hand dexterity

Dexterity dysfunction is a key feature of disability in many neurological and non-neurological diseases. The Nine-Hole Peg Test (NHPT) is the most used test to assess hand dexterity in clinical practice but presents limitations. A new graphic test to enhance objective evaluation of the of the dominant hand dexterity is proposed. The task consists in drawing a continuous line in paths composed by a part with multiple orthogonal changes of direction (‘meander’), and a second part derived from the Archimedean spiral (‘spiral’). The test was validated in 200 healthy controls and 93 neurological patients. 48 patients performed also the NHPT. Several parameters were analyzed, among which total time, total length, number of touches and number of crossings. Healthy subjects display statistically significant differences with respect to pathological subjects in the case of total time, number of touches, and number of crossings (p<0.001), but not in the case of total length (p = 0.27) needed to complete the second sheet. Moreover, healthy controls display a learning effect, the time needed to complete the second sheet was significantly lower than for the first sheet (p<0.001), and an inverse correlation with age was observed (r = 0.56, p<0.001). The comparison between the NHPT and the new test showed a strong positive correlation (r = 0.71, p<0.001) whereas touches and crossing a weak positive one (r = 0.35, p = 0.01). The new test distinguishes between a slow but precise performance and a fast but imprecise performance, thus providing additional information with respect to NHPT

A new test for equilibrium based on clinopyroxene-melt pairs: Clues on the solidification temperatures of Etnean alkaline melts at post-eruptive conditions

We have performed new global regression analyses to calibrate a model of equilibrium between clinopyroxene and co-existing melt. Then we have applied this model to a restricted but important range of clinopyroxene and melt compositions from Mt. Etna volcano. The degree of disequilibrium is determined through the comparison between components “predicted” for clinopyroxene via regression analyses of clinopyroxene-liquid pairs in equilibrium conditions, with those “measured” in the analyzed crystals. The model is tested using compositions not included into the calibration dataset, i.e., clinopyroxene-melt pairs obtained from equilibrium and cooling rate experiments conducted at ambient pressure on an Etnean trachybasalt. The experiments were duplicated at the NNO+1.5 and QFM oxygen buffering conditions estimated for magmas at Mt. Etna. Both equilibrium and disequilibrium clinopyroxene-melt pairs from the experiments were also used as input data for one of the most recent thermometers based on the Jd-DiHd exchange reaction. Results from calculations indicate that, under rapid cooling rate conditions, clinopyroxenes do not equilibrate with the melt. Consequently, the thermometers predict higher crystallization temperatures compared to the final experimental temperature, prior to rapid quenching of the experiment. The systematic difference between expected and measured compositions and temperatures allows us to calibrate a model that describes undercooling based on disequilibrium exchange reactions. We use this new tool to estimate the thermal history of naturally cooled lava flows and dikes at Mt. Etna volcano

Bilateral radial artery pseudoaneurysms associated with bilateral ulnar artery atresia: a case report.

Pseudoaneurysms of the radial artery are uncommon and most often localized in an area of penetrating vascular trauma or iatrogenic injury. Hypoplasia of the ulnar artery is even more rare. We report a case of bilateral radial artery pseudoaneurysms associated with complete absence of any ulnar contribution to the vascularity of the hand. A patient presented with bilateral tender masses adjacent to the anatomic snuff boxes that interfered with hand function. After confirming that these masses were bilateral radial artery pseudoaneurysms, resection of the pseudoaneurysms and microscopic reconstruction of the arterial segments preserved vascular integrity of the hands and provided relief of the patient\u27s pain