149 research outputs found
Hyperspectral classification of Cyperus esculentus clones and morphologically similar weeds
Cyperus esculentus (yellow nutsedge) is one of the world's worst weeds as it can cause great damage to crops and crop production. To eradicate C. esculentus, early detection is key-a challenging task as it is often confused with other Cyperaceae and displays wide genetic variability. In this study, the objective was to classify C. esculentus clones and morphologically similar weeds. Hyperspectral reflectance between 500 and 800 nm was tested as a measure to discriminate between (I) C. esculentus and morphologically similar Cyperaceae weeds, and between (II) different clonal populations of C. esculentus using three classification models: random forest (RF), regularized logistic regression (RLR) and partial least squares-discriminant analysis (PLS-DA). RLR performed better than RF and PLS-DA, and was able to adequately classify the samples. The possibility of creating an affordable multispectral sensing tool, for precise in-field recognition of C. esculentus plants based on fewer spectral bands, was tested. Results of this study were compared against simulated results from a commercially available multispectral camera with four spectral bands. The model created with customized bands performed almost equally well as the original PLS-DA or RLR model, and much better than the model describing multispectral image data from a commercially available camera. These results open up the opportunity to develop a dedicated robust tool for C. esculentus recognition based on four spectral bands and an appropriate classification model
High performance pavement markings enhancing human, camera and lidar detection
Papers presented virtually at the 41st International Southern African Transport Conference on 10-13 July 2047A Safe System Approach is built on several complementary safety layers provided by the
car, the road infrastructure and improved driver behavior, through education or
enforcement. Historically road markings and traffic signs have focused on the driver impact
by human detection and making the infrastructure better visible in all weather and traffic
situations.
More recently the adaptation of the road to machine vision has become very relevant due
to the developments in advanced driver-assistance systems (ADAS) and autonomous
vehicles (AV). Better road markings are required to improve the confidence of ADAS, and
secondly to lay the base for higher levels of vehicle automation. The General Safety
Regulation in the EU already mandates ADAS in new vehicle models. In 2024 all new
registered vehicles need to be equipped with several ADAS, including Lane Keeping
Assist (LKA) or Lane Departure Warning (LDW) systems.
The human eyes and cameras are the sensors currently used have limitations in detecting
road markings under certain conditions e.g., glare from sunlight or oncoming vehicles, rain,
fog, low light nighttime conditions. All-weather performing (AW) tapes contain the latest
developed high optics road markings, made of a mix of higher refractive index (R.I. mix 1,9
and 2,4) beads to provide reflectivity both in dry and wet condition when compared to the
conventional (traditional) paint road markings with the optics of R.I 1,5 to 1,7 that perform
mainly under dry conditions. This paper covers how better or improved road markings can
influence both human and machine vision, with focus on camera and Light Detection and
Ranging (LiDAR) sensors.
It has been determined that high performance (RI>1,7) road markings help to increase the
level of detection by both camera and LiDAR sensors, as well as human eyes. Particularly
an All-Weather performing road marking tape was detected from significantly longer
distances in wet and rainy conditions compared to traditional markings
The clinical and immunological basis of early food introduction in food allergy prevention
IgE-mediated food allergy has an estimated prevalence of 6%–10% in developed countries. Allergen avoidance has long been the main focus in the prevention of food allergy and late solid food introduction after 6–12 months of age was recommended in high-risk infants. However, the rising prevalence of food allergy despite delayed exposure to allergens and the observations that IgE-mediated sensitization to food products could even occur before the introduction of solid foods resulted in a shift towards early solid food introduction as an attempt to prevent IgE-mediated food allergy. Since then, many trials focused on the clinical outcome of early allergen introduction and overall seem to point to a protective effect on the development of IgE-mediated food allergies. For non-IgE-mediated diseases of food allergy, evidence of early food introduction seems less clear. Moreover, data on the underlying immunological processes in early food introduction is lacking. The goal of this review is to summarize the available data of immunological changes in early food introduction to prevent IgE and non-IgE mediated food allergy
Pattern of recurrence in patients with a pathologically complete response after neoadjuvant chemoradiotherapy and surgery for oesophageal cancer
BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) and surgery is a widely used treatment for locally advanced resectable oesophageal cancer, with 20-50 per cent of patients having a pathological complete response (pCR). Disease, however, still recurs in 20-30 per cent of these patients. The aim of this study was to assess the pattern of recurrence in patients with a pCR after nCRT and surgery. METHODS: All patients with a pCR after nCRT and surgery included in the phase II and III CROSS (ChemoRadiotherapy for Oesophageal followed by Surgery Study) trials (April 2001 to December 2008) and after the CROSS trials (September 2009 to October 2017) were identified. The site of recurrence was compared with the applied radiation and surgical fields. Outcomes were median time to recurrence, and overall and progression-free survival. RESULTS: A total of 141 patients with a median follow-up of 100 (i.q.r. 64-134) months were included. Some 29 of 141 patients (20,6 per cent) developed recurrence. Of these, four had isolated locoregional recurrence, 15 had distant recurrence only, and ten had both locoregional and distant recurrence. Among the 14 patients with locoregional recurrences, five had recurrence within the radiation field, seven outside the radiation field, and two at the border. Median time to recurrence was 24 (10-62) months. The 5-year overall survival rate was 74 per cent and the recurrence-free survival rate was 70 per cent. CONCLUSION: Despite good overall survival, recurrence still occurred in 21 per cent of patients. Most recurrences were distant, outside the radiation and surgical fields
Peptide receptor radiotherapy: a new option for the management of aggressive fibromatosis on behalf of the Italian Sarcoma Group
The management of aggressive fibromatosis (AF) is problematic, and few options are available to patients unsuitable for surgery and resistant to external-beam radiation therapy (EBRT). We report on two patients with fast-growing recurrences of AF resistant to EBRT who obtained protracted clinical benefits with 90Y-DOTATOC. 90Y-DOTATOC should be further investigated in this setting
Intensity-modulated radiation therapy (IMRT) vs. 3D conformal radiotherapy (3DCRT) in locally advanced rectal cancer (LARC): dosimetric comparison and clinical implications
<p>Abstract</p> <p>Purpose</p> <p>To compare target dose distribution, comformality, normal tissue avoidance, and irradiated body volume (IBV) in 3DCRT using classic anatomical landmarks (c3DCRT), 3DCRT fitting the PTV (f3DCRT), and intensity-modulated radiation therapy (IMRT) in patients with locally advanced rectal cancer (LARC).</p> <p>Materials and methods</p> <p>Fifteen patients with LARC underwent c3DCRT, f3DCRT, and IMRT planning. Target definition followed the recommendations of the ICRU reports No. 50 and 62. OAR (SB and bladder) constraints were D5 ≤ 50 Gy and Dmax < 55 Gy. PTV dose prescription was defined as PTV95 ≥ 45 Gy and PTVmin ≥ 35 Gy. Target coverage was evaluated with the D95, Dmin, and Dmax. Target dose distribution and comformality was evaluated with the homogeneity indices (HI) and Conformity Index (CI). Normal tissue avoidance of OAR was evaluated with the D5 and V40. IBV at 5 Gy (V5), 10 Gy (V10), and 20 Gy (V20) were calculated.</p> <p>Results</p> <p>The mean GTV95, CTV95, and PTV95 doses were significantly lower for IMRT plans. Target dose distribution was more inhomogeneous after IMRT planning and 3DCRTplans had significantly lower CI. The V40 and D5 values for OAR were significantly reduced in the IMRT plans .V5 was greater for IMRT than for f3DCRT planning (p < 0.05) and V20 was smaller for IMRT plans(p < 0.05).</p> <p>Conclusions</p> <p>IMRT planning improves target conformity and decreases irradiation of the OAR at the expense of increased target heterogeneity. IMRT planning increases the IBV at 5 Gy or less but decreases the IBV at 20 Gy or more.</p
SPECTRUM, VELOCITY AND DRIFT OF DROPLETS SPRAYED BY NOZZLES WITH AND WITHOUT AIR INDUCTION AND MINERAL OIL
Efficacy and feasibility of stereotactic radiotherapy after folfirinox in patients with locally advanced pancreatic cancer (LAPC-1 trial)
Background: We conducted a multicentre phase II trial to investigate feasibility and antitumor activity of sequential FOLFIRINOX and Stereotactic Body Radiotherapy (SBRT) in patients with locally advanced pancreatic cancer (LAPC), (LAPC-1 trial). Methods: Patients with biopsy-proven LAPC treated in four hospitals in the Netherlands between December 2014 and June 2017. Patients received 8 cycles of FOLFIRINOX followed by SBRT (5 fractions/8 Gy) if no tumour progression after the FOLFIRINOX treatment was observed. Primary outcome was 1-year overall survival (OS). Secondary outcomes were median OS, 1-year progression-free survival (PFS), treatment-related toxicity, and resection rate. The study is registered with ClinicalTrials.gov, NCT02292745, and is completed. Findings: Fifty patients were included. Nineteen (38%) patients did not receive all 8 cycles of FOLFIRINOX, due to toxicity (n = 12), disease progression (n = 6), or patients’ preference (n = 1). Thirty-nine (78%) patients received the SBRT treatment. The 1-year OS and PFS were 64% (95% CI: 50%-76%) and 3
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