A DTA/GC for the in Situ Identification of the Martian Surface Material

The composition and mineralogy of the Martian surface material remain largely unknown. To determine its composition and mineralogy, several techniques are being considered for in situ analyses of the Martian surface material during missions to Mars. We have successfully developed, constructed, and tested a laboratory DTA/GC. The DTA is a Dupont model 1600 high temperature DTA coupled with a GC equipped with a MID detector. The system is operated by a Sun Sparc 11 workstation. When gas evolves during a thermal chemical event, it is shunted into the GC and the temperature is recorded in association with the specific thermal event. We have used this laboratory instrument to define experimental criteria necessary for determining the composition and mineralogy of the Martian surface in situ (e.g., heating of sample to 1100 C to distinguish clays). Our studies indicate that DTA/GC will provide a broad spectrum of mineralogical and evolved gas data pertinent to exobiology, geochemistry, and geology

Penguin Mediated B Decays at BABAR

We report on preliminary results of searches for penguin mediated B decays based on 20.7 fb^{-1} of data collected at the Y(4S) peak with the BABAR detector at PEP-II. The following branching fractions have been measured: BR(B+ --> phi K+) = (7.7^{+1.6}_{-1.4} +- 0.8)*10^{-6}, BR(B0 --> phi K0) = (8.1^{+3.1}_{-2.5} +- 0.8)*10^{-6}, BR(B+ --> phi K*+) = (9.7^{+4.2}_{-3.4} +- 1.7)*10^{-6}, BR(B0 --> phi K*0) = (8.7^{+2.5}_{-2.1} +- 1.1)*10^{-6}, BR(B+--> omega pi+) = (6.6^{+2.1}_{-1.8} +- 0.7)*10^{-6}, BR(B --> eta K^*0) = (19.8^{+6.5}_{-5.6} +-1.7)*10^{-6}, where the first error is statistical and the second systematic. For several other modes we report upper limits on their branching fractions; for example for the following flavor-changing neutral current decays, BR(B--> K l+ l-) K* l+ l-) < 2.5*10^{-6}, at 90% Confidence Level (C.L.)

Cell-free prediction of protein expression costs for growing cells

Translating heterologous proteins places significant burden on host cells, consuming expression resources leading to slower cell growth and productivity. Yet predicting the cost of protein production for any given gene is a major challenge, as multiple processes and factors combine to determine translation efficiency. To enable prediction of the cost of gene expression in bacteria, we describe here a standard cell-free lysate assay that provides a relative measure of resource consumption when a protein coding sequence is expressed. These lysate measurements can then be used with a computational model of translation to predict the in vivo burden placed on growing E. coli cells for a variety of proteins of different functions and lengths. Using this approach, we can predict the burden of expressing multigene operons of different designs and differentiate between the fraction of burden related to gene expression compared to action of a metabolic pathway

Comparison between the environmental performance of buildings made of reinforced concrete and timber

In order to reduce the environmental impact of the construction industry, the case of natural material (such as timber) is pursued. However, is the use of low-impact materials sufficient to decrease the overall environmental impact of a building? The answer is not trivial, because there are many parameters that affect sustainability, in addition to the unitary environmental impact of the building materials. Through this article, an evaluation of the total CO2 emission in buildings made of reinforced concrete and CLT panels is carried out. The entire life cycle (LCA) of the materials is considered, as well as the CO2 emissions derived from heating and chilling. The relationship between CO2 emissions and building height is also taken into account along with weather conditions.The structures and envelopes of a three - storey family house and of a multi-storey residential building are designed from a structural and thermal point of view, respectively. In order to consider the climatic effects, three locations with very different weather conditions are assumed (i.e. Catania, Turin, Oslo). The carbon footprint of three different structures is considered, namely RC frame made with cast-in-situ structural elements, precast RC panels and timber CLT structure.The quantification of the carbon footprint allows to notice how the overall structural and thermal performances, including the thermal mass, affect the environment performance

The carbon footprint of normal and high-strength concrete used in low-rise and high-rise buildings

To reduce the mass of CO2 released into atmosphere by the construction industry, the performance strategy can be adopted. It is based on the use of High-Strength Concrete (HSC) in alternative to Normal-Strength Concrete (NSC). Such concretes are herein considered to design the reinforced concrete structures of three buildings, having 14, 30 and 60 floors, respectively. For each building, the structural analyses, carried out for four classes of concrete (i.e., C25, C40, C60 and C80) in accordance with Eurocode 2, provides different dimensions of the structural elements. In other words, the amount of CO2, released in the atmosphere due to the production of the structural materials, is a function of both concrete strength and height of the building. As a result, the minimum impact of low-rise buildings occurs when the structural elements are made with NSC. Conversely, only when HSC is used to cast the structural elements of tall buildings, can the carbon footprint be effectively reduced. Keywords: Performance strategy, Carbon footprint, FEM analyses, Reinforced concrete structure

Introduction:Understanding Neo-nomadic Mobilities beyond Self-actualisation

In 2018, Noel Salazar presented a paper at the 5th World Humanities Forum in Busan, South Korea, entitled “Moveo Ergo Sum: Mobility as Vital to Humanity and Its (Self)image,” in which he reflected on the existential need for people to move. Moveo ergo sum became the motto for the 2021 Global Mobility Humanities Conference (GMHC), encouraging us to think about the multiple ways in which mobility intersects with the construction of modern subjectivities (Salazar, “Introduction”). The expression recalled a quote from one of Fabiola Mancinelli’s research participants, a digital nomad from the US, whose words and unusual biography as a location-independent entrepreneur read like a declaration of selfactualisation through mobility, the desire to realise her full potential by constantly putting herself outside her comfort zone: “Travel is who I am, and this is not negotiable” (426). This remarkable coincidence was the trigger for us to propose the panel “Understanding Neonomadic Mobilities beyond Self-actualisation” to unpack the mobility-identity nexus as an analytical lens to explore the phenomenon of contemporary nomads

Interpretation of Voltage Measurements in Cutting Torches

Anode-cathode and nozzle-cathode voltages, plenum pressure and gas mass flow measurements in a low current (30 A) cutting torch, operated with oxygen gas, are used as inputs for an electrical model coupled to a simplified fluid model, in order to infer some properties of the plasma-gas structure that are difficult to measure. © 2006 American Institute of Physics.Fil:Kelly, H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Minotti, F.O. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Superfast front propagation in reactive systems with anomalous diffusion

We study a reaction diffusion system where we consider a non-gaussian process instead of a standard diffusion. If the process increments follow a probability distribution with tails approaching to zero faster than a power law, the usual qualitative behaviours of the standard reaction diffusion system, i.e., exponential tails for the reacting field and a constant front speed, are recovered. On the contrary if the process has power law tails, also the reacting field shows power law tail and the front speed increases exponentially with time. The comparison with other reaction-transport systems which exhibit anomalous diffusion shows that, not only the presence of anomalous diffusion, but also the detailed mechanism, is relevant for the front propagation.Comment: 4 pages and 4 figure

Viking and Mars Rover exobiology

Other than Earth, Mars is the planet generating the greatest interest among those researching and contemplating the origin and distribution of life throughout the universe. The similarity of the early environments of Earth and Mars, and the biological evolution on early Earth provides the motivation to seriously consider the possibility of a primordial Martian biosphere. In 1975 the Viking project launched two unmanned spacecraft to Mars with the intent of finding evidence of the existence of present or past life on this planet. Three Viking Biology experiments were employed: the Labeled Release experiment, the Gas Exchange Experiment, and the Pyrolytic Release experiment. Each of these three experiments tested for microbial existence and utilization of a substrate by examining the gases evolved from specific chemical reactions. Although the results of these experiments were inconclusive, they inferred that there are no traces of extant life on Mars. However, the experiments did not specifically look for indication of extinct life. Therefore, most of the exobiologic strategies and experiments suggested for the Mars Rover Sample Return Mission involve searching for signature of extinct life. The most significant biological signatures and chemical traces to detect include: isotopic and chemical signatures of metabolic activity, anomalous concentrations of certain metals, trace and microfossils, organically preserved materials, carbonates, nitrates, and evaporites

Performance and egg quality of laying hens fed flaxseed: highlights on n-3 fatty acids, cholesterol, lignans and isoflavones

Flaxseed is a rich source of \u3b1-linolenic acid and phytoestrogens, mainly lignans, whose metabolites (enterodiol and enterolactone) can affect estrogen functions. The present study evaluated the influence of dietary flaxseed supplementation on reproductive performance and egg characteristics (fatty acids, cholesterol, lignans and isoflavones) of 40 Hy-Line hens (20/group) fed for 23 weeks a control diet or the same diet supplemented with 10% of extruded flaxseed. The flaxseed diet had approximately three times the content of lignans (2608.54 ng/g) as the control diet, mainly secoisolariciresinol diglucoside (1534.24 v. 494.72 ng/g). When compared with the control group, hens fed flaxseed showed a similar deposition rate (72.0% v. 73.9%) and egg yield. Furthermore, there was no effect of flaxseed on the main chemical composition of the egg and on its cholesterol content. Estradiol was higher in the plasma of the control group (1419.00 v. 1077.01 pg/ml) probably due to the effect of flaxseed on phytoestrogen metabolites. The plasma lignans were higher in hens fed flaxseed, whereas isoflavones were lower, mainly due to the lower equol value (50.52 v. 71.01 ng/ml). A similar trend was shown in eggs: the flaxseed group had higher level of enterodiol and enterolactone, whereas the equol was lower (198.31 v. 142.02 ng/g yolk). Secoisolariciresinol was the main lignan in eggs of the flaxseed group and its concentration was three times higher then control eggs. Flaxseed also improved the n-3 long-chain polyunsaturated fatty acids of eggs (3.25 v. 0.92 mg/g egg), mainly DHA, however, its oxidative status (thiobarbituric reactive substances) was negatively affected. In conclusion, 10% dietary flaxseed did not affect the productive performance of hens or the yolk cholesterol concentration, whereas the lignans and n-3 polyunsaturated fatty acid content of eggs improved. Further details on the competition between the different dietary phytoestrogens and their metabolites (estrogen, equol, enterodiol and enterolactone) should be investigated