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Double exponential inseparability of Robinson subsystem Q+
No full textJournal of Symbolic Logic
Volume 76, Issue 1, March 2011, Pages 94-124
Double-exponential inseparability of robinson subsystem (Article)
Egidi, L. , Faglia, G.
Dipartimento di Informatica, Università del Piemonte Orientale A. Avogadro, Viale T. Michel.11, 15121 Alessandria, Italy
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Abstract
In this work a double exponential time inseparability result is proven for a finitely axiomatizable first order theory Q+. The theory, subset of Presburger theory of addition S+, is the additive fragment of Robinson system Q. We prove that every set that separates Q+ from the logically false sentences of addition is not recognizable by any Turing machine working in double exponential time. The lower bound is given both in the non-deterministic and in the linear alternating time models. The result implies also that any theory of addition that is consistent with Q+-in particular any theory contained in S+-is at least double exponential time difficult. Our inseparability result is an improvement on the known lower bounds for arithmetic theories. Our proof uses a refinement and adaptation of the technique that Fischer and Rabin used to prove the difficulty of S +. Our version of the technique can be applied to any incomplete finitely axiomatizable system in which all of the necessary properties of addition are provable
G protein oncogenes in pituitary tumors
No full textG proteins are involved in the transduction of external signals from cell surface receptors to intracellular effectors. Somatic mutations activating the a-subunit of Gs (the stimulatory regulatory protein of adenylyl cyclase) by inhibiting its intrinsic GTPase activity have been first identified in human GH-secreting adenomas and subsequently found in thyroid tumors and in McCune-Albright syndrome. It has been therefore proposed that the gene encoding the GS a-subunit may be converted into an oncogene (gsp for GS protein) in cell types that proliferate in response to cAMP. Since several G proteins mediate signaling pathways that are effective in coupling external stimuli to cell proliferation, it appears most likely that in the near future other G protein oncogenes will be identified in human tumors
Effects of obesity, total fasting and realimentation on L-thyroxine (T4), 3,5,3', - L-triiodothyronine (T3), - 3,3',5'-L-triiodorhyronine (rT3), - thyroxine binding globulin (TBG), cortisol, thyrotophin, cortisol-binding globulin (CBG), transferrin, alpha2-haptoglobin and complement C 3 in serum
Full text linkEarly Detection of Esca Disease in Asymptomatic Vines by Raman Spectroscopy
Full text linkEarly detection of esca disease in grapevines is fundamental to calibrating proper pesticide use in sustainable vineyard management systems. This article is a proof of concepts showing that the Raman spectroscopy (RS) combined with a chemometric analysis can be used as a nondestructive sensor to implement precision agriculture for early detection of the disease through a new biochemical marker. Symptomatic and symptomless branches from an esca-developing vine and from healthy esca-free vines from a vineyard were investigated by RS and chemometrics, using the final outcome of the specific disease syndrome as the final benchmark. As a result, the model is always able to correctly classify all the test samples, showing auspicious results to perform precision agriculture-based future therapeutic approaches
Quadriceps and hand-grip strength in adults with childhood-onset growth hormone deficiency
No full textThe effects of chronic growth hormone (GH) deficiency on muscle size and strength of postural (quadriceps) and non-postural (hand-grip) muscle groups, as well as on vertical jump capacity, were evaluated in six adults with childhood-onset GH deficiency. Data obtained were compared to those recorded in an age-, sex- and exercise-matched healthy control group. Thigh muscle plus bone cross-sectional area (CSA(M+B)) of the dominant quadriceps was significantly lower (p < 0.001) than in controls, while the CSA(M+B)/(Body height)2 ratio was similar to that of controls. The maximum voluntary contraction (MVC) of the quadriceps of patients was significantly lower (p < 0.002) than in controls, while no differences existed in the quadriceps force expressed per unit area (MVC/CSA) between patients and controls. As far as hand-grip was concerned, the CSA(M+B) of the dominant forearm was significantly lower (p < 0.003) than in controls, while the CSA(M+B)/(Body height)2 ratio was no different. The hand-grip MVC of patients was significantly lower (p < 0.004) than in controls, while no differences existed in the MVC/CSA ratio. It is noteworthy also that no difference existed in the hand-grip to quadriceps MVC ratio of the two groups. Furthermore, no differences were found in the vertical lump capacity, because both Δ Height and Δ Height/Body weight of patients were not significantly different from those of controls. In conclusion, our study suggests that GH deficiency seems to reduce the size and strength of postural and non-postural muscle groups to the same extent. However, these findings are likely to be attributed to a simple dimensional scaling, because their CSA/(Body height)2, MVC/CSA and vertical jump capacity were comparable to those of controls
Physical vapor deposition of copper oxide nanowires
No full textCopper oxide nanowires have been successfully prepared by vapor phase transport technique. The deposition conditions strongly influence the morphology of the nanostructures and in turn their electrical and functional properties. Micro-structural investigation and analysis of the electrical properties were performed together with electrical and functional characterization. Transmission electron microscopy confirmed the high crystalline properties and elemental composition of copper oxide nanostructure. P-type semiconductor and sensing behavior has been proved
New trends in optical resonant bio-chemical sensing
No full textThe development of innovative bio-chemical sensors is of great importance to make new devices available to the market. In the current paper, we review recent trends on optical resonant sensors that may involve plasmonic or geometrical resonances. In all cases, resonance is activated by excitation with electromagnetic light of proper wavelength. Plasmonic hot electrons, obtained by shining light on metal nanoparticle decorated metal oxides, can bring new effects in physicochemical processes, affecting electrical and optical properties (absorption/transmission, Surface Enhanced Raman Spectroscopy SERS). Geometrical resonances are involved in Mie and Whispering Gallery Modes (WGM) based sensing, including metasurfaces for optical detection of molecules and nonlinear effects in metamaterials
Study of the degradation of biobased plastic after stress tests in water
No full textResearch on compostable bioplastics has recently obtained performances comparable to traditional plastics, like water vapor permeability, sealability, and UV transmission. Therefore, it is crucial to create new tools that help the developers of new polymeric composites study them quickly and cost-effectively. In this work, Raman spectroscopy (RS) was proposed as a versatile tool to investigate the degradation of biobased plastics after a stress test in water: this approach is a novelty for food packaging. Treatments at room temperature (RT) and 80◦ C were selected, considering that these biopolymers can be used to packaging ready meals. The investigation was carried out on single-layer sheets of poly-lactic acid (PLA), cellulose ester (CE), poly-butylene succinate (PBS), polybutylene adipate-co-terephthalate (PBAT), and a new composite material obtained by coupling CE and PBS (BB951) and PLA and CE (BB961). The vibrational modes of the water-treated materials at RT and 80◦ C were compared to the Raman spectra of the pristine bioplastic, and the morphologies of the polymers were analyzed by scanning electron microscopy (SEM) and optical microscopy. Composite sheets were the plastics which were mostly affected by the 80◦ C treatment in water, through changes in morphology (wrinkling with alternate white and transparent zones), as was especially the case for BB951. The Raman spectra acquired in different zones showed that the vibrations of BB951 were generally maintained in transparent zones but reduced or lacking in white zones. At the same time, the single-layer materials were almost unchanged. For BB961, the Raman vibrations were only slightly modified, in agreement with the visual inspection. The results suggest that RS detects the specific chemical bond that was modified, helping us understand the degradation process of biobased plastics after water treatment
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