18 research outputs found
A Simple Method to Estimate Weed Control Threshold by Using RGB Images from Drones
The estimation of the infestation level in a field and the consequent determination of the
economic threshold is a basic requisite to rationalize post-emergence weeding. In this study, a simple
and inexpensive procedure to determine the economic threshold based on weed cover is proposed.
By using high-resolution RGB images captured by a low-cost drone, a free downloadable app for
image processing and common spreadsheet software to perform the model parametrization, two
different methods have been tested. The first method was based on the joint estimation of the two
parameters involved in weed cover calculation, whereas the second method required the availability
of further images for the separate estimation of the first parameter. The reliability of the two methods
has been evaluated through the comparison with observed data and the goodness of fit in parameter
calibration has been verified by calculating appropriate quality indices. The results showed an
acceptable estimation of the weed cover value for the second method with respect to observed data
(0.24 vs. 0.17 m2 and 0.17 vs. 0.14 m2, by processing images captured at 10 and 20 m, respectively),
whereas the estimations obtained with the first method were disappointing (0.35 vs. 0.17 m2 and 0.33
vs. 0.14 m2, by processing images captured at 10 and 20 m, respectively)
Precision Nitrogen Management In Camelina: Preliminary Results From A Case Study In Central Italy
Nowadays, the use of advanced technologies in agriculture is mandatory in order to increase cropping system sustainability and quality. To guarantee a higher yield, farmers need to ensure the best health of their crops with, at the same time, the least environmental impact. Particular attention is generally paid to nitrogen fertilization since nitrogen use efficiency in modern agriculture is very low. It means that a lot of synthetic chemicals are wasted rather than utilized by crops with consequent environmental issues. The use of spectral reflectance indices, such as the normalized difference vegetation index (NDVI) and chlorophyll index (Dualex), are reliable indicators to determine N status of crop plants. In this contest, very scarce knowledge is available about the response of camelina - a promising oilseed crop for food, feed, and the bio-based industry - to different N rates as well as on the use of remote/proximal sensing. So, this study aimed to evaluate the effect of N fertilization rate and timing on camelina seed yield and quality. At the same time, biochemical parameters and NDVI by using proximal sensing techniques were assessed with the aim to optimise camelina agronomic management
L'uso dei droni per il monitoraggio della flora infestante su una coltura di mais
In un campo coltivato, la gestione delle piante infestanti mette spesso l’agricoltore di fronte ad una scelta, se attuare un controllo di pre-emergenza oppure uno di post-emergenza.
Nel caso in cui si opti per il post-emergenza, sarebbe buona pratica che qualunque scelta tecnica adottata fosse basata su un’attività di monitoraggio (scouting), volta a valutare l’effettiva convenienza di operare il trattamento e la scelta dei principi attivi più efficaci.
Le informazioni di cui l’agricoltore ha bisogno sono di carattere sia quantitativo che qualitativo.
Nel primo caso bisogna valutare se effettivamente il livello di infestazioni superi o meno la soglia economica di intervento, valutando, cioè, se il trattamento comporta più costi o benefici e se è quindi giustificato o meno da un punto di vista economico.
Inoltre, l’agricoltore deve conoscere anche la composizione della flora infestante, in termini di specie, scegliendo quindi i principi attivi più efficaci per l’inattivazione delle malerbe.
Lo scouting è un’operazione che, normalmente, è sempre stata fatta dagli agricoltori effettuando la valutazione in campo, basandosi sulla propria esperienza e conoscenza.
Chiaramente i limiti di questo tipo di attività sono legati all’accuratezza e la precisione, che non potranno essere costanti su tutto l’appezzamento. Per non parlare del tempo che questa operazione richiede, direttamente proporzionali alle dimensioni della superficie da monitorare.
Queste criticità , però, legate alla necessità che sia fisicamente l’agricoltore a dover effettuare il monitoraggio, potrebbero essere superate sfruttando i passi avanti che sono stati fatti nel campo del telerilevamento (remote-sensing). Questa disciplina infatti permette di ricavare informazioni, quantitative e qualitative a distanza, tramite sensori montati su diversi tipi di vettori.
In questo lavoro di tesi è stata valutata l’efficienza dello scouting aereo, fatto con SAPR (Sistema Aeromobile a Pilotaggio Remoto) nell’effettuare il monitoraggio delle infestanti su una coltura di mais.
Durante la fase di volo sono state acquisite immagi, con diversi tipi di sensori (RGB, multispettrale e termico), che successivamente sono state processate per ottenere delle ortofoto.
Queste ortofoto sono state, quindi, classificate con l’obiettivo di distinguere all’interno di esse le tre macro-componenti presenti (terreno, mais, infestanti) e successivamente sono stati valutati i risultati dell’elaborazione cercando di individuare quale fosse la procedura di classificazione più efficace e quale fosse la sensoristica più adatta allo svolgimento di tale operazione.
Tutti i dati ottenuti da drone sono stati confrontati con dati raccolti a terra con metodologie tradizionali così da poterne valutare l’attendibilità e le possibilità di applicazione
Food Neophobia and scarce olfactory performances are linked to oral microbiota
People suffering from Food Neophobia (FN) tend to follow an unbalanced dietary pattern and show worse olfactory performances. However, scarce data are available on the possible relationships between FN, olfactory performances and the oral microbiota. The purpose of this work was to understand whether FN and its consequences on orthonasal and retronasal olfaction are related to specific signatures in the oral microbiota. We carried out 16S rRNA gene sequencing of salivary specimens from 83 subjects, whose olfactory performances and Food Neophobia were previously estimated. Our results show that the oral microbiota of people showing high neophobic traits and scarce olfactory performances is enriched in several taxa, such as the periodontal pathogen Porphyromonas gingivalis. We hypothesize that these traits are likely attributable to unbalanced dietary patterns, which would need confirmation from dietary records of recruited neophobic subjects
Urgent endovascular revascularization in acute on chronic critical limb ischemia
Background: The aim of this study was to evaluate early and one-year outcomes of urgent endovascular treatment in patients with acute on chronic critical limb ischemia (CLI). Methods: Between January 2012 and December 2013 104 patients with acute on chronic CLI (Rutherford class 4-6) were referred to two tertiary hospitals. In all cases the urgent endovascular revascularization was considered the first therapeutic option. Twenty-seven patients (26%) were excluded from this approach (long occlusion >30 cm of the femoro-popliteal tract and/or massive gangrene with abscess/osteomyelitis/necrotizing fasciitis). Results: Seventy-seven out of 104 patients received an urgent endovascular treatment. They were predominantly male (43, 55.8%) with a mean age of 76.5 years (range 47-94). In 67 cases (87%) the patients had leg/foot lesions (54, 70.1%, Rutherford class 5, and 13, 16.9%, Rutherford class 6). During the follow-up (mean duration 6.2 months, range 1-24 months) the healing of the lesions and the relief of rest pain were obtained in 46 cases (59.7%). Estimated one-year primary patency, primary assisted patency, secondary patency, and limb salvage rates were 63.6%, 68.3, 69%, and 84.1%, respectively. At uni- and multivariate analysis patients in Rutherford class 6 showed poor results in terms of primary patency, primary assisted patency, secondary patency, and limb salvage (P<0.001). Conclusions: Urgent endovascular treatment in selected patients with acute on chronic CLI represents a safe and effective option with good results in terms of healing of the ischemic lesions, relief of rest pain, and limb salvage. Patients in Rutherford class 6 showed fewer benefits with this approach
Spectral Response of Camelina (<i>Camelina sativa</i> (L.) Crantz) to Different Nitrogen Fertilization Regimes under Mediterranean Conditions
Knowledge about the spectral response of camelina under different regimes of nitrogen (N) fertilization is very scarce. Therefore, 2-year open-field trials were carried out in the 2021 and 2022 growing seasons with the aim of evaluating the spectral response of spring camelina to four different N fertilization regimes by using remote (UAV) and proximal (leaf-clip Dualex) sensing techniques. The tested treatments were: (i) control: no N application (T0); (ii) top dressing: 60 kg N ha−1 before stem elongation (T1); basal dressing: 60 kg N ha−1 at sowing (T2); basal + top dressing combination: 60 kg N ha−1 at sowing + 60 kg N ha−1 before stem elongation (T3). Camelina seed yield and N use efficiency were strongly affected by fertilization regimes, with the best results obtained at T2. A reduction in plant development and seed yield was detected in 2022, probably due to the rise in air temperatures. A significant effect of both growing season and N fertilization was observed on the photosynthetic pigments content with the T1 highest values in 2022. The highest seed oil content was achieved at T1, while the protein content increased with increasing N, with the best values at T3. Positive and significant correlations were observed among several vegetation indices obtained through UAV flights (NDVI, MRS705, FGCC) and seed yield, as well as between FGCC and leaf N concentration. Overall, these findings demonstrate the feasibility of utilizing remote sensing techniques from UAVs for predicting seed yield in camelina
How To Diagnose and Manage Infected Endografts after Endovascular Aneurysm Repair
The prevalence of endograft infections (EI) after endovascular abdominal aortic aneurysm repair is below 1%. With the growing number of patients with aortic endografts and the aging population, the number of patients with EI might also increase. The diagnosis is based on an association of clinical symptoms, imaging, and microbial cultures. Angio-computed tomography is currently the gold-standard technique for diagnosis. Low-grade infection sometimes requires nuclear medicine imaging to make a correct diagnosis. There is no good evidence to guide management so far. In the case of active gastrointestinal bleeding, pseudoaneurysm, or extensive perigraft purulence involving adjacent organs, an invasive treatment should always be attempted. In the other cases (the majority), when there is not an immediate danger to the patient's life, a conservative management is started with a proper antimicrobial therapy. Any infectious cavity can be percutaneously drained. Management depends on the patient's condition and a tailored approach should always be offered. In the case of a patient who is young, has a good life expectancy, or in whom there is absence of significant comorbidities, a surgical attempt can be proposed. Surgical techniques favor, in terms of mortality, patency, and reinfection rate, the in situ reconstruction. Choice of technique relies on the center and the operator's experience. Long-term antibiotic therapy is always required in all cases, with close monitoring of the C-reactive protein
One-year experience of a regional service model of teleconsultation for planning and treatment of complex thoracoabdominal aortic disease
Objective: The objective of this study was to report the methodology and 1-year experience of a regional service model of teleconsultation for planning and treatment of complex thoracoabdominal aortic disease (TAAD). Methods: Complex TAADs without a feasible conventional surgical repair were prospectively evaluated by vascular surgeons of the same public health service (National Health System) located in a huge area of 22,994 km2with 3.7 million inhabitants and 11 tertiary hospitals. Surgeons evaluated computed tomography scans and clinical details that were placed on a web platform (Google Drive; Google, Mountain View, Calif) and shared by all surgeons. Patients gave informed consent for the teleconsultation. The surgeon who submits a case discusses in detail his or her case and proposes a possible therapeutic strategy. The other surgeons suggest other solutions and options in terms of grafts, techniques, or access to be used. Computed tomography angiography, angiography, and clinical outcomes of cases are then presented at the following telemeetings, and a final agreement of the operative strategy is evaluated. Teleconsultation is performed using a web conference service (WebConference.com; Avaya Inc, Basking Ridge, NJ) every month. An inter-rater agreement statistic was calculated, and the κ value was interpreted according to Altman's criteria for computed tomography angiography measurements. Results: The rate of participation was constant (mean number of surgeons, 11; range, 9-15). Twenty-four complex TAAD cases were discussed for planning and operation during the study period. The interobserver reliability recorded was moderate (κ = 0.41-0.60) to good (κ = 0.61-0.80) for measurements of proximal and distal sealing and very good (κ = 0.81-1) for detection of any target vessel angulation >60 degrees, significant calcification (circumferential), and thrombus presence (>50%). The concordance for planning and therapeutic strategy among all participants was complete in 16 cases. In one case, the consultation was decisive for creating an innovative therapeutic strategy; in the remaining seven cases, the strategy proposed by the patient's surgeon was changed completely after the discussion. Technical success was the same (100%) if concordance in planning was present initially or not. Overall 6-month mortality was 4%, 0% for those patients with initial concordance in planning vs 12% for those without initial concordance (P =.33). Surgery was always performed in a tertiary hospital by local surgeons, and in two cases (8%) external surgeons joined the local surgical team. Conclusions: Such a regional service of teleconsultation may be of value in standardizing the treatment and derived costs of complex TAADs in a huge region under the same health provider. The shared decision-making strategy may be of medical-legal value as well