1,404 research outputs found
Growth of Rhodococcus sp. strain BCP1 on gaseous n-alkanes: New metabolic insights and transcriptional analysis of two soluble di-iron monooxygenase genes
Rhodococcus sp. strain BCP1 was initially isolated for its ability to grow on gaseous n-alkanes, which act as inducers for the co-metabolic degradation of low-chlorinated compounds. Here, both molecular and metabolic features of BCP1 cells grown on gaseous and short-chain n-alkanes (up to n-heptane) were examined in detail. We show that propane metabolism generated terminal and sub-terminal oxidation products such as 1- and 2-propanol, whereas 1-butanol was the only terminal oxidation product detected from n-butane metabolism. Two gene clusters, prmABCD and smoABCD-coding for Soluble Di-Iron Monooxgenases (SDIMOs) involved in gaseous n-alkanes oxidation-were detected in the BCP1 genome. By means of Reverse Transcriptase-quantitative PCR (RT-qPCR) analysis, a set of substrates inducing the expression of the sdimo genes in BCP1 were assessed as well as their transcriptional repression in the presence of sugars, organic acids, or during the cell growth on rich medium (Luria-Bertani broth). The transcriptional start sites of both the sdimo gene clusters were identified by means of primer extension experiments. Finally, proteomic studies revealed changes in the protein pattern induced by growth on gaseous- (n-butane) and/or liquid (n-hexane) short-chain n-alkanes as compared to growth on succinate. Among the differently expressed protein spots, two chaperonins and an isocytrate lyase were identified along with oxidoreductases involved in oxidation reactions downstream of the initial monooxygenase reaction step
Optimal measurement strategies for fast entanglement detection
With the advance of quantum information technology, the question of how to
most efficiently test quantum circuits is becoming of increasing relevance.
Here we introduce the statistics of lengths of measurement sequences that
allows one to certify entanglement across a given bi-partition of a multi-qubit
system over the possible sequence of measurements of random unknown states, and
identify the best measurement strategies in the sense of the (on average)
shortest measurement sequence of (multi-qubit) Pauli measurements. The approach
is based on the algorithm of truncated moment sequences that allows one to deal
naturally with incomplete information, i.e. information that does not fully
specify the quantum state. We find that the set of measurements corresponding
to diagonal matrix elements of the moment matrix of the state are particularly
efficient. For symmetric states their number grows only like the third power of
the number of qubits. Their efficiency grows rapidly with , leaving
already for less than a fraction of randomly chosen entangled
states undetected.Comment: 12 pages, 9 figure
Size and asymmetry of the reaction entrance channel: influence on the probability of neck production
The results of experiments performed to investigate the Ni+Al, Ni+Ni, Ni+Ag
reactions at 30 MeV/nucleon are presented. From the study of dissipative
midperipheral collisions, it has been possible to detect events in which
Intermediate Mass Fragments (IMF) production takes place. The decay of a
quasi-projectile has been identified; its excitation energy leads to a
multifragmentation totally described in terms of a statistical disassembly of a
thermalized system (T4 MeV, E4 MeV/nucleon). Moreover, for
the systems Ni+Ni, Ni+Ag, in the same nuclear reaction, a source with velocity
intermediate between that of the quasi-projectile and that of the quasi-target,
emitting IMF, is observed. The fragments produced by this source are more
neutron rich than the average matter of the overall system, and have a charge
distribution different, with respect to those statistically emitted from the
quasi-projectile. The above features can be considered as a signature of the
dynamical origin of the midvelocity emission. The results of this analysis show
that IMF can be produced via different mechanisms simultaneously present within
the same collision. Moreover, once fixed the characteristics of the
quasi-projectile in the three considered reactions (in size, excitation energy
and temperature), one observes that the probability of a partner IMF production
via dynamical mechanism has a threshold (not present in the Ni+Al case) and
increases with the size of the target nucleus.Comment: 16 pages, 7 figures, accepted for publication on Nuclear Physics
On modelling damage in composite laminates using the Ritz method and continuum damage mechanics
In this work, a Ritz formulation for the analysis of damage initiation and evolution in
composite plates under progressive loading is presented. The proposed model assumes a first order
shear deformation theory and considers geometric non-linearities through the von Karman
assumptions. The damage is modelled through Continuum Damage Mechanics. A set of results is
presented to show the potential of the method and highlight some issues to be addressed by suitable
developments of the method
Preliminary evidence of a potential reproductive aggregation area of the common stingray Dasyatis pastinaca (Linnaeus, 1758) (Chondrichthyes - Dasyatidae) in the Central Mediterranean Sea
Shallow and coastal aggregations of batoids are poorly documented in the Mediterranean Sea, despite being likely threatened by multiple anthropogenic pressures. We report the first observations of a potential summer reproductive aggregation of the common stingray (Dasyatis pastinaca). The recurrent presence in previous years of several pregnant females, a mature male and a female with fresh bite wounds was recorded in shallow waters by recreational scuba divers and scientists in Scilla Bay (Strait of Messina, Italy), a location with unique oceanographic features in the Central Mediterranean Sea. These observations suggest that the area could be used as a parturition and mating site in early summer, and this is significant for the conservation of this Vulnerable species
Low temperature deactivation of Ge heavily n-type doped by ion implantation and laser thermal annealing
International audienceHeavy doping of Ge is crucial for several advanced micro-and optoelectronic applications, but, at the same time, it still remains extremely challenging. Ge heavily n-type doped at a concentration of 1 X 10(20) cm(-3) by As ion implantation and melting laser thermal annealing (LTA) is shown here to be highly metastable. Upon post-LTA conventional thermal annealing As electrically deactivates already at 350 degrees C reaching an active concentration of similar to 4 x 10(19) cm(-3). No significant As diffusion is detected up to 450 degrees C, where the As activation decreases further to similar to 3 x 10(19) cm(-3). The reason for the observed detrimental deactivation was investigated by Atom Probe Tomography and in situ High Resolution X-Ray Diffraction measurements. In general, the thermal stability of heavily doped Ge layers needs to be carefully evaluated because, as shown here, deactivation might occur at very low temperatures, close to those required for low resistivity Ohmic contacting of n-type Ge
Nest guarding behaviour of a temperate wrasse differs between sites off Mediterranean CO2 seeps
Organisms may respond to changing environmental conditions by adjusting their behaviour (i.e., behavioural plasticity). Ocean acidification (OA), resulting from anthropogenic emissions of carbon dioxide (CO2), is predicted to impair sensory function and behaviour of fish. However, reproductive behaviours, and parental care in particular, and their role in mediating responses to OA are presently overlooked. Here, we assessed whether the nesting male ocellated wrasse Symphodus ocellatus from sites with different CO2 concentrations showed different behaviours during their breeding season. We also investigated potential re-allocation of the time-budget towards different behavioural activities between sites. We measured the time period that the nesting male spent carrying out parental care, mating and exploring activities, as well as changes in the time allocation between sites at ambient (~400 μatm) and high CO2 concentrations (~1000 μatm). Whilst the behavioural connectance (i.e., the number of linkages among different behaviours relative to the total amount of linkages) was unaffected, we observed a significant reduction in the time spent on parental care behaviour, and a significant decrease in the guarding activity of fish at the high CO2 sites, with a proportional re-allocation of the time budget in favour of courting and wandering around, which however did not change between sites. This study shows behavioural differences in wild fish living off volcanic CO2 seeps that could be linked to different OA levels, suggesting that behavioural plasticity may potentially act as a mechanism for buffering the effects of ongoing environmental change. A reallocation of the time budget between key behaviours may play a fundamental role in determining which marine organisms are thriving under projected OA
Plastic adjustments of biparental care behavior across embryonic development under elevated temperature in a marine ectotherm
Phenotypic plasticity in parental care investment allows organisms to promptly respond to rapid environmental changes by potentially benefiting offspring survival and thus parental fitness. To date, a knowledge gap exists on whether plasticity in parental care behaviors can mediate responses to climate change in marine ectotherms. Here, we assessed the plasticity of parental care investment under elevated temperatures in a gonochoric marine annelid with biparental care, Ophryotrocha labronica, and investigated its role in maintaining the reproductive success of this species in a warming ocean. We measured the time individuals spent carrying out parental care activities across three phases of embryonic development, as well as the hatching success of the offspring as a proxy for reproductive success, at control (24℃) and elevated (27℃) temperature conditions. Under elevated temperature, we observed: (a) a significant decrease in total parental care activity, underpinned by a decreased in male and simultaneous parental care activity, in the late stage of embryonic development; and (b) a reduction in hatching success that was however not significantly related to changes in parental care activity levels. These findings, along with the observed unaltered somatic growth of parents and decreased brood size, suggest that potential cost-benefit trade-offs between offspring survival (i.e., immediate fitness) and parents' somatic condition (i.e., longer-term fitness potential) may occur under ongoing ocean warming. Finally, our results suggest that plasticity in parental care behavior is a mechanism able to partially mitigate the negative effects of temperature-dependent impacts
THE MAIN PORTAL OF THE CATHEDRAL OF MONREALE: FIRST GEOMETRIC ANALYSIS AND INTERPRETIVE ASSESSMENT OF ARCHITECTURAL FEATURES
Nowadays, 3D documentation of architectural assets is becoming a demanding task for the valorisation of Cultural Heritage especially after a restoration project. The 3D documentation can be used for detailed analysis of specific elements, for monitoring the state of conservation and for valorisation actions. The paper describes the results of the 3D close-range photogrammetry survey of the main portal of the Cathedral of Monreale (Palermo, Italy). The Cathedral is one the most important monumental complexes in Sicily that, for its high historical and artistic importance has been inscribed on UNESCO\u2019s World Heritage List since 2015. The main portal of the Cathedral has been recently restored. The restoration work has given the opportunity to evidence small details of the sculptural decorations and to carry out new interpretative analysis of the bas-reliefs.
The main purpose of the work is to obtain a detailed 3D model and a high-resolution ortophoto of the entire portal and of some architectural details. The study was used to evaluate the most appropriate technical solutions for the 3D survey and to define the most suitable parameters for image acquisition and data processing
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