Identification of Ships in Satellite Images Heiselberg, Peder; Pedersen, Hasse B.; Sorensen, Kristian A. ...
IEEE journal of selected topics in applied earth observations and remote sensing,
01/2024, Volume:
17
Journal Article
Peer reviewed
Open access
Satellite imagery has become a fundamental part for maritime monitoring and safety. Correctly estimating a ship's identity is a vital tool. We present a method based on facial recognition for ...identifying ships in satellite images. A large ship dataset is constructed from Sentinel-2 multispectral images and annotated by matching to the Automatic Identification System. Our dataset contains 7.000 unique ships, for which a total of 16.000 images are acquired. The method uses a convolutional neural network to extract a feature vector from the ship images and embed it on a hypersphere. Distances between ships can then be calculated via the embedding vectors. The network is trained using a triplet loss function, such that minimum distances are achieved for identical ships and maximum distances to different ships. Comparing a ship image to a reference set of ship images yields a set of distances. Ranking the distances provides a list of the most similar ships. The method correctly identifies a ship on average 60% of the time as the first in the list. Larger ships are easier to identify than small ships, where the image resolution is a limitation.
Background
Extended-spectrum β-lactamases (ESBLs) are an increasing challenge in the treatment of urinary tract infections (UTIs), and also in the community. We aimed to investigate the ...characteristics of patients with UTIs due to ESBL-producing
Escherichia coli
and to assess the risk factors for ESBLs in community-acquired isolates.
Methods
We performed a retrospective study from January 1, 2007 to December 31, 2009 at a tertiary care teaching hospital in Switzerland, comparing patients with community-acquired versus healthcare-associated UTIs due to ESBL-producing
E. coli
. Additionally, we investigated the antimicrobial susceptibility of these isolates.
Results
A total of 123 patients were studied, of whom 79 (64%) had community-acquired and 44 (36%) had healthcare-associated UTIs. Community-acquired isolates were associated with acute uncomplicated UTIs (odds ratio OR 6.62, 95% confidence interval CI 1.83–36.5,
P
< 0.001). Risk factors were recurrent UTI (OR 3.04, 95% CI 1.14–9.14,
P
= 0.022) and female sex (OR 2.46, 95% CI 1.01–6.08). Community-acquired ESBL-producing
E. coli
urinary isolates showed high resistance rates to most of the currently used oral antimicrobial agents, including β-lactam antibiotics (amoxicillin–clavulanic acid, 69.6% resistance), quinolones (ciprofloxacin, 84.8% resistance; norfloxacin, 83.9% resistance), and trimethoprim–sulfamethoxazole (75.9% resistance), except for nitrofurantoin (15% resistance) and fosfomycin (0% resistance).
Conclusion
UTI due to ESBL-producing
E. coli
are emerging, and also in a country with low antibiotic use. Because of increasing antibiotic resistance rates of
E. coli
to current standard therapy and because of the resistance patterns of ESBL-producing
E. coli
, guidelines for the management of UTIs must be revised. Fosfomycin or nitrofurantoin are recommended for the first-line empirical oral treatment of community-acquired uncomplicated UTIs.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
Colonization with Mycobacterium chimaera and other non-tuberculous mycobacteria (NTM) has been reported for heater-cooler devices (HCDs) produced by several manufacturers. Up until now, exclusively ...LivaNova (London, UK) HCDs have been associated with M. chimaera infections after cardiac surgery. The vast majority of studies on HCD colonization were cross-sectional.
We were interested in longitudinal dynamics of mycobacterial growth in HCD water samples and analysed data of a prospective mycobacterial surveillance of five LivaNova 3T HCDs.
Five LivaNova HCDs were subjected to prospective mycobacterial surveillance. For each HCD and the total of HCDs, results of mycobacterial detection were analyzed. Logistic regression was applied to model the association between growth of any NTM or M. chimaera and duration of HCD use.
Non-tuberculous mycobacteria were isolated in 319 (48.0%, 21 water samples grew more than one mycobacterial species) of a total of 665 water samples. The most frequently detected species were M. chimaera (N = 247/319, 77.4%), Mycobacterium gordonae (46/319, 14.4%) and Mycobacterium paragordonae (34/319, 10.7%). Detection rates increased prospectively for any NTM (odds ratio (OR) per year in use: 1.60, 95% confidence interval (CI) 1.17–2.24, P<0.001) and for M. chimaera (OR per year in use: 1.67, 95% CI 1.11–2.57, P<0.01).
Longer duration of HCD use was associated with higher detection rates for any NTM and M. chimaera, respectively.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Reconstructive vascular surgery has become increasingly common. Vascular graft infections (VGIs) are serious complications, leading to increased morbidity and mortality. Previously described risk ...factors for VGIs include groin incisions, wound infections, and comorbidities. We aimed to identify modifiable predictors for VGIs as targets for infection prevention strategies.
Participants of the prospective Vascular Graft Infection Cohort (VASGRA) with surgery between 2013 and 2017 were included. The observation time was calculated from surgery until a confirmed VGI or the last follow-up. Variables were assessed by infection status, using non-parametric tests. Univariable and multivariable Cox proportional hazard regression models, adjusted for demographic factors, were applied to assess risk factors for a VGI.
A total of 438 predominantly male (83.1%) patients with a median age of 71 years (interquartile range IQR 63 - 76) contributed to 554 person years of follow-up. Thereof, 39 (8.9%) developed a VGI, amounting to an incidence rate of 7.0/100 person years. We found incisional surgical site infections (adjusted hazard ratio aHR 10.09, 95% CI 2.88 - 35.34); hemorrhage (aHR 4.92, 1.28-18.94); renal insufficiency (aHR 4.85, 1.20 - 19.61); inadequate perioperative prophylaxis in patients with an established antibiotic treatment, compared to the additional application of perioperative prophylaxis (aHR 2.87, 95% CI 1.17 - 7.05); and procedure time increases of 1-hour intervals (aHR 1.22, 95% CI 1.08 - 1.39) to be risk factors for VGIs.
We identified procedure time; inadequate perioperative prophylaxis, especially among patients with an established antibiotic treatment; and several postsurgical infectious and non-infectious complications as modifiable, predictive factors for VGIs and, therefore, as keys to improved surveillance programs and prevention strategies.
NCT01821664.
This study investigated MAO-A inhibitory activity of methanol extract of
Calluna vulgaris (L.) Hull., which traditionally has been used as a nerve calming remedy.
A methanolic extract of
Calluna ...vulgaris was partitioned against heptane, ethyl acetate and water. The three fractions were tested in a photometric peroxidase linked MAO-A bioassay. The ethyl acetate phase showed the highest MAO-A inhibitory activity. Quercetin was isolated by VLC through bioassay-guided fractionation and purified by re-crystallisation. The structure was elucidated by LC–MS and
1H NMR.
The IC
50-value for MAO-A inhibition by quercetin was 18
±
0.2
μM in an assay where the IC
50-value for MAO-A inhibition by clorgylin was 0.2
±
0.02
μM.
The content of quercetin in
Calluna vulgaris might explain the reported nerve calming effect of the plant.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
To isolate a plant-derived compound with efflux inhibitory activity towards the NorA transporter of Staphylococcus aureus.
Bioassay-guided isolation was used, with inhibition of ethidium bromide ...efflux via NorA as a guide. Characterization of activity was carried out using MIC determination and potentiation studies of a fluoroquinolone antibiotic in combination with the isolated compound. Everted membrane vesicles of Escherichia coli cells enriched with NorA were prepared to study efflux inhibitory activity in an isolated manner.
The ethanolic extract of Persea lingue was subjected to bioassay-guided fractionation and led to the isolation of the known compound kaempferol-3-O-α-L-(2,4-bis-E-p-coumaroyl)rhamnoside (compound 1). Evaluation of the dose-response relationship of compound 1 showed that ethidium bromide efflux was inhibited, with an IC(50) value of 2 μM. The positive control, reserpine, was found to have an IC(50) value of 9 μM. Compound 1 also inhibited NorA in enriched everted membrane vesicles of E. coli. Potentiation studies revealed that compound 1 at 1.56 mg/L synergistically increased the antimicrobial activity of ciprofloxacin 8-fold against a NorA overexpresser, and the synergistic activity was exerted at a fourth of the concentration necessary for reserpine. Compound 1 was not found to exert a synergistic effect on ciprofloxacin against a norA deletion mutant. The 2,3-coumaroyl isomer of compound 1 has been shown previously not to cause acute toxicity in mice at 20 mg/kg/day.
Our results show that compound 1 acts through inhibition of the NorA efflux pump. Combination of compound 1 with subinhibitory concentrations of ciprofloxacin renders a wild-type more susceptible and a NorA overexpresser S. aureus susceptible.
The international outbreak of cardiac-surgery-associated Mycobacterium chimaera infections was traced back to infectious aerosols originating from contaminated water reservoirs of heater-cooler ...devices (HCDs). In general, non-tuberculous mycobacteria (NTM) frequently colonize water systems and can contaminate medical devices. Data on detection of NTM other than M. chimaera in samples gathered from HCDs are scarce. The present study summarizes prospective mycobacterial surveillance of five HCDs over more than 4 years.
Five LivaNova 3T (London, UK) HCDs, acquired factory-new in 2014, were followed prospectively. Until mid-April 2014, the HCDs were maintained according to the manufacturer's recommendations, and subsequently, they were maintained according to an intensified in-house protocol including exhaust air evacuation. Mycobacterial surveillance cultures consisted of monthly water samples gathered from patient and cardioplegia circuits, as well as airflow samples.
Of 441 water samples, 170 (38.6%) revealed NTM growth. The most frequently detected NTM were M. chimaera N=120 (67.4%), Mycobacterium gordonae N=35 (19.7 %) and Mycobacterium paragordonae N=17 (9.6%). Growth of NTM, M. chimaera and M. paragordonae was significantly more common in water samples derived from the patient circuit than the cardioplegia circuit of the HCD. Three (2.0%) of 150 air samples grew NTM.
Growth of NTM in HCD water samples was common. Diverse NTM species were detected, with M. chimaera being the most common. The majority of air samples remained negative. The relevance of NTM other than M. chimaera contaminating HCDs is poorly defined, but a recent report on an HCD-associated outbreak with Mycobacterium abscessus confirmed a potential threat.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A growing number of Mycobacterium chimaera infections after cardiosurgery have been reported by several countries. These potentially fatal infections were traced back to contaminated heater–cooler ...devices (HCDs), which use water as a heat transfer medium. Aerosolization of water contaminated with M. chimaera from HCDs enables airborne transmission to patients undergoing open chest surgery. Infection control teams test HCD water samples for mycobacterial growth to guide preventive measures. The detection limit of M. chimaera in water samples, however, has not previously been investigated.
To determine the detection limit of M. chimaera in water samples using laboratory-based serial dilution tests.
An M. chimaera strain representative of the international cardiosurgery-associated M. chimaera outbreak was used to generate a logarithmic dilution series. Two different water volumes, 50 and 1000mL, were inoculated, and, after identical processing (centrifugation, decantation, and decontamination), seeded on mycobacteria growth indicator tube (MGIT) and Middlebrook 7H11 solid media.
MGIT consistently showed a lower detection limit than 7H11 solid media, corresponding to a detection limit of ≥1.44 × 104cfu/mL for 50mL and ≥2.4cfu/mL for 1000mL water samples. Solid media failed to detect M. chimaera in 50mL water samples.
Depending on water volume and culture method, major differences exist in the detection limit of M. chimaera. In terms of sensitivity, 1000mL water samples in MGIT media performed best. Our results have important implications for infection prevention and control strategies in mitigation of the M. chimaera outbreak and healthcare water safety in general.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
PDF
