Thermal behavior of Quantum Cellular Automaton wires

We investigate the effect of a finite temperature on the behavior of logic circuits based on the principle of Quantum Cellular Automata (QCA) and of ground state computation. In particular, we focus on the error probability for a wire of QCA cells that propagates a logic state. A numerical model and an analytical, more approximate, model are presented for the evaluation of the partition function of such a system and, consequently, of the desired probabilities. We compare the results of the two models, assessing the limits of validity of the analytical approach, and provide estimates for the maximum operating temperature.Comment: 15 pages, 7 figures, uses revte

Devices based on 2D materials for on-chip amplification of ionization charges

Pixels detectors are widely used ionizing radiation detection devices in high-energy physics (HEP)experiments. Segmented detectors have been employed for many years due to the need to simul-taneously track the thousands of particles emerging from modern colliders. For more preciseand accurate measurements one would like to have faster, less noisy and smaller pixels, but cur-rent technology imposes several limits on these characteristics. The aim of this work is to ex-plore the possible applications of bi-dimensional materials such as Graphene or transition metaldichalcogenide monolayers (TMDs) to address these problems. In particular, one wants to de-termine whether nano-electronic devices based on 2D materials could be used to obtain built-inpre-amplification of the pixel signal, thus achieving better detection performance. The workingprinciple is the field-effect modulation of the channel conductivity in a 2D material-based tran-sistor, due to the presence of ionization charges in a silicon absorber. Several architectures aretested, and a final device of choice is presented, with a sketch of a realistic readout system andits noise figure. The conductance modulation due to incoming particles is found to be more than30%, resulting in a strong current signal, which leads to very favourable signal-to-noise ratios (SNR)

Three Dimensional Visualization and Fractal Analysis of Mosaic Patches in Rat Chimeras: Cell Assortment in Liver, Adrenal Cortex and Cornea

The production of organ parenchyma in a rapid and reproducible manner is critical to normal development. In chimeras produced by the combination of genetically distinguishable tissues, mosaic patterns of cells derived from the combined genotypes can be visualized. These patterns comprise patches of contiguously similar genotypes and are different in different organs but similar in a given organ from individual to individual. Thus, the processes that produce the patterns are regulated and conserved. We have previously established that mosaic patches in multiple tissues are fractal, consistent with an iterative, recursive growth model with simple stereotypical division rules. Fractal dimensions of various tissues are consistent with algorithmic models in which changing a single variable (e.g. daughter cell placement after division) switches the mosaic pattern from islands to stripes of cells. Here we show that the spiral pattern previously observed in mouse cornea can also be visualized in rat chimeras. While it is generally held that the pattern is induced by stem cell division dynamics, there is an unexplained discrepancy in the speed of cellular migration and the emergence of the pattern. We demonstrate in chimeric rat corneas both island and striped patterns exist depending on the age of the animal. The patches that comprise the pattern are fractal, and the fractal dimension changes with the age of the animal and indicates the constraint in patch complexity as the spiral pattern emerges. The spiral patterns are consistent with a loxodrome. Such data are likely to be relevant to growth and cell division in organ systems and will help in understanding how organ parenchyma are generated and maintained from multipotent stem cell populations located in specific topographical locations within the organ. Ultimately, understanding algorithmic growth is likely to be essential in achieving organ regeneration in vivo or in vitro from stem cell populations

Electron dynamics in intentionally disordered semiconductor superlattices

We study the dynamical behavior of disordered quantum-well-based semiconductor superlattices where the disorder is intentional and short-range correlated. We show that, whereas the transmission time of a particle grows exponentially with the number of wells in an usual disordered superlattice for any value of the incident particle energy, for specific values of the incident energy this time increases linearly when correlated disorder is included. As expected, those values of the energy coincide with a narrow subband of extended states predicted by the static calculations of Dom\'{\i}nguez-Adame {\em et al.} [Phys. Rev. B {\bf 51}, 14 ,359 (1994)]; such states are seen in our dynamical results to exhibit a ballistic regime, very close to the WKB approximation of a perfect superlattice. Fourier transform of the output signal for an incident Gaussian wave packet reveals a dramatic filtering of the original signal, which makes us confident that devices based on this property may be designed and used for nanotechnological applications. This is more so in view of the possibility of controllingthe outp ut band using a dc electric field, which we also discuss. In the conclusion we summarize our results and present an outlook for future developments arising from this work.Comment: 10 pagex, RevTex, 13 Postscript figures. Physical Review B (in press

Effect of mannanoligosaccharides supplementation on caecal microbial activity of rabbits

A total of 200 weaned (35 days) hybrid Hyla rabbits were randomly divided among five groups housed in bicellular cages (20 cages per group). Between 35 and 60 days of age, the groups were submitted to the following treatments: group ANT (positive control) fed a basal diet supplemented with antibiotics (colistin sulphate, 144 mg/kg; tylosin, 100 mg/kg; and oxytetracyclin, 1000 mg/kg); groups MOS-0.5, MOS-1.0 and MOS-1.5 fed the basal diet supplemented with 0.5, 1.0 and 1.5 g/kg mannanoligosaccharides (MOS), respectively; another group fed the basal diet without antibiotics or mannanoligosaccarides supplementation (negative control). Along the trial, an episode of epizootyc rabbit enteropathy occurs so that in the control group mortality rate was very high (78%) and survivor rabbits showed severe symptoms of disease (diarrhoea). Thus, the control group was discarded from the trial. At 60 days of age, samples of caecal content were collected from 10 rabbits per group and used as inocula for an in vitro gas production trial. At the end of fermentation (120 h of incubation), organic matter digestibility (OMd), cumulative gas production, fermentation kinetics, pH, volatile fatty acid (VFA) and NH3 productions were measured. Inoculum from MOS-1.0 rabbits showed the significant higher values of OMd (64.21%, P < 0.05), gas production (262.32 ml/g, P < 0.05), acetate (96.99 mmol/g OM, P < 0.05) and butyrate (26.21 mmol/g OM, P < 0.05) than the other groups. Slight differences were recorded among the groups ANT, MOS-0.5 and MOS-1.5. In addition, branched chain acids, in proportion to total VFAs, were significantly higher in MOS-1.0 inoculum (0.04, P < 0.05). MOS are able to affect fermentation activity of caecal micro-organism, but their activities seem not proportional to their level in the diet. Copyright © The Animal Consortium 2010

Comparison of caecal and faeces fermentation characteristics of ostrich by in vitro gas production technique

To compare caecal and faecal fermentation characteristics, ostrich caecal content (CI) and faeces (FI) were used as inocula for an in vitro gas production trial in which four substrates (dehydrated alfalfa, alfalfa hay, maize and a commercial concentrate) were tested. The fermentation characteristics (degraded organic matter, OMd; potential gas production, A; acetate; branched chain proportion, BCP) were studied by inoculum and substrate. CI and FI showed significant differences for almost all the fermentation parameters, and CI had higher values than FI for OMd (76.83 vs. 72.79%, p<0.01), A (250.3 vs. 229.3 ml/g, p<0.01), acetate (57.91 vs. 53.20 mmol/l, p<0.01) and BCP (0.031 vs. 0.027, p<0.05). CI and FI showed differences in carbohydrates and protein fermentation, but the interaction between the tested effects was not significant. The regression equations to estimate caecal fermentation characteristics from faeces suggest the possibility to use faeces as inoculum alternative to faeces. © 2011 Taylor & Francis

Myocardial and microvascular injury due to Coronavirus disease 2019

Over the past few months, health systems worldwide have been put to the test with the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Even though the leading clinical manifestations of the SARS-CoV-2 infection involve the respiratory tract, there is a non-negligible risk of systemic involvement leading to the onset of multi-organ failure with fatal consequences. Since the onset of COVID-19, patients with underlying cardiovascular disease have been at increased risk of poor clinical outcomes with higher death rates. Moreover, the occurrence of new-onset cardiac complications is not uncommon among patients hospitalised for COVID-19. Of importance, a significant portion of COVID-19 patients present with myocardial injury. Herein, the authors discuss the mechanisms leading to myocardial and microvascular injury in SARS-CoV-2 infection and their clinical implications

Effects of Anthocyanin Supplementation and Ageing Time on the Volatile Organic Compounds and Sensory Attributes of Meat from Goat Kids

The aim of this study was to assess the effects of dietary anthocyanin addition on volatile compounds of meat from goat kids during ageing. For this work, 60 male and female kids were divided into two groups: red orange and lemon extract (RLE group; n = 30), which received an RLE extract (90 mg/kg of live weight); and control (CON group; n = 30). The phytoextract in dry powder form was rich in bioflavonoids such as flavanones (about 16%) and anthocyanins (about 3%). After slaughtering, the longissimus thoracis et lumborum muscle was aged at 4◦C. The volatile organic compound (VOC) and sensorial analyses were carried out at 1, 3 and 7 days. A total of 10 chemical families were identified during the ageing process. Aldehydes were the most abundant VOC, followed by ketones and alcohols. Their contents increased during the process, showing after 7 days of ageing mean values of 20,498, 2193 and 1879 ng/g of meat, respectively. Regarding dietary effects, carboxylic acids, hydrocarbons and thiols presented significant differences between treatments, with higher carboxylic acid contents observed in RLE samples (437 vs. 467 ng/g of meat for CON and RLE batches, respectively; p < 0.05). On the contrary, hydrocarbons (436 vs. 254 ng/g of meat for CON and RLE batches, respectively) and thiols (160 vs. 103 ng/g of meat for CON and RLE batches, respectively) displayed significantly (p < 0.01) higher amounts in CON compared to the RLE group. Regarding ageing time, the tenderness, juiciness, odour and overall assessment parameters showed significantly higher scores at the end of the whole process (p < 0.05). On the other hand, only odour displayed significant differences between treatments, reaching higher scores in CON samples (p < 0.05). Therefore, ageing time improved the sensorial properties (tenderness, juiciness, odour and overall assessment) and the VOC content, whereas the inclusion of anthocyanins in the kids’ diet did not have a great impact on the properties of aged meat

Non Equilibrium Electronic Distribution in Single Electron Devices

The electronic distribution in devices with sufficiently small diemnsions may not be in thermal equilibrium with their surroundings. Systems where the occupancies of electronic states are solely determined by tunneling processes are analyzed. It is shown that the effective temperature of the device may be higher, or lower, than that of its environment, depending on the applied voltage and the energy dependence of the tunneling rates. The I-V characteristics become asymmetric. Comparison with recent experiments is made