3,601 research outputs found
A Comparison of Assistive Methods for Suturing in MIRS
In Minimally Invasive Robotic Surgery (MIRS) a robot is interposed between the surgeon and the surgical site to increase the precision, dexterity, and to reduce surgeon's effort and cognitive load with respect to the standard laparoscopic interventions. However, the modern robotic systems for MIRS are still based on the traditional telemanipulation paradigm, e.g. the robot behaviour is fully under surgeon's control, and no autonomy or assistance is implemented. In this work, supervised and shared controllers have been developed in a vision-free, human-in-the-Ioop, control framework to help surgeon during a surgical suturing procedure. Experiments conducted on the da Vinci Research Kit robot proves the effectiveness of the method indicating also the guidelines for improving results
Occurrence of Blastocystis-subtypes in patients from Italy revealed association of ST3 with a healthy gut microbiota
An epidemiological survey on Blastocystis was carried out enrolling a total of 2524 subjects referred to the Umberto I Academic Hospital in Rome, for the routine parasitological exams, during 2017–2018. The studied population included a sample of immunocompromised individuals (N = 130) followed at the same hospital. DNA sequencing of the small subunit rRNA gene (SSU rDNA) locus was performed on samples positive to the coproparasitological analysis to molecular characterize the Blastocystis-subtypes. Microscopical analysis detected Blastocystis in 192/2524 (7.6%) of the enrolled subjects. It was the organism most frequently identified in the analysed faecal samples diagnosed in single infection (5.6%) or in co-infection with other enteric protozoa (2%). Furthermore, it was found mainly in immunocompromised patients (22.3%) compared to immunocompetent ones (6.8%). As expected, ST3 was the most occurring subtype identified in 40% of the subjects, followed by ST1 (29%), ST2 (16%), ST4 (12%), and ST7 (3%). Next-generation sequencing (NGS) of the 16S rDNA was performed on a sub-sample of Blastocystis-ST3-carriers, homogenous by age and gender, as well as on Blastocystis-free subjects, to profile and compare their gut bacterial composition. A higher bacterial diversity was found in ST3-Blastocystis-carriers, which exhibited a high abundance of Prevotella, Methanobrevibacter and Ruminococcus while, a high percentage of Bacteroides was found in Blastocystis-free subjects. This study evidenced the presence of Blastocystis in 7.6% of faecal samples in Italy and a high circulation of the protist among immunocompromised patients (22.3%). Molecular characterization of positive samples evidenced the occurrence of five different subtypes, including zoonotic ST such as the ST7, highlighting the risk of transmission from animals. Study of the gut microbiota composition confirms previous evidences according to which, the colonisation by Blastocystis would be linked with an eubiotic gut characterized by potentially beneficial species such as Prevotella and Ruminococcus, rather than with a dysbiotic state, with a high abundance of Enterobacteriaceae, and corroborated the role of the protist as “an old friend” of the human gut
GOOGLE EARTH ENGINE: APPLICATION OF ALGORITHMS FOR REMOTE SENSING OF CROPS IN TUSCANY (ITALY)
Abstract. Remote sensing has become an important mean to assess crop areas, specially for the identification of crop types. Google Earth Engine (GEE) is a free platform that provides a large number of satellite images from different constellations. Moreover, GEE provides pixel-based classifiers, which are used for mapping agricultural areas. The objective of this work is to evaluate the performance of different classification algorithms such as Minimum Distance (MD), Random Forest (RF), Support Vector Machine (SVM), Classification and Regression Trees (CART) and Na¨ıve Bayes (NB) on an agricultural area in Tuscany (Italy). Four different scenarios were implemented in GEE combining different information such as optical and Synthetic Aperture Radar (SAR) data, indices and time series. Among the five classifiers used the best performers were RF and SVM. Integrating Sentinel-1 (S1) and Sentinel-2 (S2) slightly improves the classification in comparison to the only S2 image classifications. The use of time series substantially improves supervised classifications. The analysis carried out so far lays the foundation for the integration of time series of SAR and optical data
A Reconfigurable Gripper for Robotic Autonomous Depalletizing in Supermarket Logistics
Automatic depalletizing is becoming a practice widely applied in warehouses to automatize and speed-up logistics. On the other hand, the necessity to adapt the preexisting logistic lines to a custom automatic system can be a limit for the application of robotic solutions into smaller facilities like supermarkets. In this work, we tackle this issue by proposing a flexible and adaptive gripper for robotic depalletizing. The gripper is designed to be assembled on the end-tip of an industrial robotic arm. A novel patent-pending mechanism allows grasping boxes and products from both the upper and the lateral side enabling the depalletizing of boxes with complex shape. Moreover, the gripper is reconfigurable with five actuated degrees of freedom, that are automatically controlled using the embedded sensors to adapt grasping to different shapes and weights
RGB-D Recognition and Localization of Cases for Robotic Depalletizing in Supermarkets
Integrating a robotic system into the depalletizing process of a supermarket demands a high level of autonomy, based on strong perceptive capabilities. This letter presents a system for detection, recognition, and localization of heterogeneous cases in a depalletizing robotic cell, using a single RGB-D camera. Such a system integrates apriori information on the content of the pallet with data from the RGB-D camera, exploiting a sequence of 2D and 3D model-based computer-vision algorithms. The effectiveness of the proposed methodology is assessed in an experiment where multiple cases and pallet configurations are considered. Finally, a complete depalletizing process is shown
Combining roller crimpers and flaming for the termination of cover crops in herbicide-free no-till cropping systems
The termination of cover crops in conventional no-till systems is mostly conducted mechanically
in combination with herbicides. Combining flaming and roller crimpers could be a viable
solution to avoid using herbicides for cover crop termination in farming systems where herbicides
are banned, or at least to reduce their use in an integrated management approach.
This research tested the effects of flaming used in combination with three different types of
roller crimpers to terminate a fall-sown cover crop mixture of winter pea and barley. The
cover crop termination rate was visually assessed in terms of percentage of green cover
provided by cover crop plants at different intervals from the termination date, and estimated
using a log-logistic non-linear regression model with four parameters. Machine performance
data are also reported. The results show that, irrespective of the roller type, flaming significantly
boosted the effect of the roller crimpers. In fact, an economic threshold for cover crop
suppression of 85% was reached only when the rollers were used in combination with flaming.
Nevertheless, none of the methods were able to reach the 100% of cover crop suppression.
In some case, the combined use of flaming and roller crimpers allowed reaching the
90% of cover crop devitalisation, which happened six weeks after the termination date.
More importantly, the use of flaming in combination with rollers shortened the time needed
to achieve the estimated levels of devitalisation, compared with the rollers used alone. We
conclude that flaming is an effective tool to increase the effectiveness of roller crimpers.
Nevertheless, further research is needed to identify solutions to overcome the barrier of the
high operational costs of flaming, which is constraining its wider adoption by farmers. Future
studies could focus, for instance, on the development of a new prototype of combined
machine for crimping and flaming the cover crops simultaneously, which could potentially
reduce the operational costs
Development of a flaming machine for the disinfection of poultry grow-out facilities
Chemical treatments are commonly adopted for poultry house sanitation.
In fact, ordinary floor disinfection is needed to deplete the pathogenic
population (i.e. various species of bacteria and fungi) and
reduce the risk of meat contamination. The increasing focus on the
health of consumers and operators, as well as on food quality, has led
farmers to consider alternative environmentally friendly methods.
Research was carried out to set up a new machine for floor disinfection
of poultry houses by open flame. The trials were run in controlled
conditions in the laboratory of the University of Pisa, Italy, and on a
private farm. The first experiment consisted of a series of test bench
trials carried out to evaluate the efficacy and the adjustment of liquefied
petroleum gas (LPG)-fed open flame burners on pre-inoculated
steel plates. In the second experiment, the operative parameters of a
custom-built 1.5 m wide mounted flaming machine were determined
and the biological effects of the treatment were compared to ordinary
chemical treatments. The results obtained were very promising. Test
bench trials showed a 4-log reduction in E. coli, and microbial determinations
carried out on-farm did not show any difference between thermal
and chemical treatment. In addition, the cost estimation showed
that thermal disinfection is approximately 4-fold cheaper than chemical
sanitation methods. The effective working capacity of the machine
was approximately 1700 m2 h–1, and the LPG consumption was approximately
16 kg per 1000 m2. Flame disinfection of poultry grow-out facilities
could represent a valid alternative to chemical disinfection
Assessment of a Chain Mower Performance for Weed Control under Tree Rows in an Alley Cropping Farming System
In the area under tree rows of alley cropping systems, coarse plant material as well as pruning material or stones may be present, so the use of a mower equipped with chains as cutting a tool could be advantageous. A mower designed for under-row weed control in orchards, equipped with an automatic tree-skipping mechanism, was modified by replacing blades with chains with the aim of evaluating its performance in an alley cropping system. A first trial was carried out in an open field to preliminarily compare the chain mower with the version equipped with blades in relation to different settings of working speed (1.6 and 2.4 km center dot h(-1)) and rotation speed of the cutting tool (1830 and 2500 rpm). Weed biomass reduction, weed cover reduction, weed height reduction, weed biomass regrowth, and clipping size were assessed. In a second trial, the performance of the mowers with different setting configurations was assessed in an alley cropping system under a more critical environmental condition for mowing, i.e., the presence of dew. Weed biomass reduction, weed cover reduction, weed height reduction, and the mowers' field capacity with different working speed settings were assessed. No major differences emerged between the mowers and the chain mower performance was comparable to that of the standard blade mower. The setting with the high working speed and high rotation speed of the cutting tool turns out to be the best compromise, obtaining a weed biomass reduction of 59.6%, a weed cover reduction of 40.9%, and a higher field capacity compared to the setting with the low working speed, with an increase of 47.9%
A 3-component extension of the Camassa-Holm hierarchy
We introduce a bi-Hamiltonian hierarchy on the loop-algebra of sl(2) endowed
with a suitable Poisson pair. It gives rise to the usual CH hierarchy by means
of a bi-Hamiltonian reduction, and its first nontrivial flow provides a
3-component extension of the CH equation.Comment: 15 pages; minor changes; to appear in Letters in Mathematical Physic
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