Neural network approach for correction of multiple scattering errors in the LISST-VSF instrument.

The LISST-VSF is a commercially developed instrument used to measure the volume scattering function (VSF) and attenuation coefficient in natural waters, which are important for remote sensing, environmental monitoring and underwater optical wireless communication. While the instrument has been shown to work well at relatively low particle concentration, previous studies have shown that the VSF obtained from the LISST-VSF instrument is heavily influenced by multiple scattering in turbid waters. High particle concentrations result in errors in the measured VSF, as well as the derived properties, such as the scattering coefficient and phase function, limiting the range at which the instrument can be used reliably. Here, we present a feedforward neural network approach for correcting this error, using only the measured VSF as input. The neural network is trained with a large dataset generated using Monte Carlo simulations of the LISST-VSF with scattering coefficients b=0.05-50m-1, and tested on VSFs from measurements with natural water samples. The results show that the neural network estimated VSF is very similar to the expected VSF without multiple scattering errors, both in angular shape and magnitude. One example showed that the error in the scattering coefficient was reduced from 103% to 5% for a benchtop measurement of natural water sample with expected b=10.6m-1. Hence, the neural network drastically reduces uncertainties in the VSF and derived properties resulting from measurements with the LISST-VSF in turbid waters.

Experimental and theoretical investigation of waveguided plasmonic surface lattice resonances.

Plasmonic nanostructures are good candidates for refractive index sensing applications through the surface plasmon resonance due to their strong dependence on the surrounding dielectric media. However, typically low quality-factor limits their application in sensing devices. To improve the quality-factor, we have experimentally and theoretically investigated two-dimensional gold nanoparticle gratings situated on top of a waveguide. The coupling between the localized surface plasmon and waveguide modes results in Fano-type resonances, with high quality-factors, very similar to plasmonic surface lattice resonances. By combining plasmonic surface lattice resonance and waveguide theory, we present a theoretical framework describing the structures. By immersing the fabricated samples in three different media we find a sensitivity of ∼50 nm/RIU and figure of merit of 8.9, and demonstrate good agreement with the theory presented. Further analysis show that the sensitivity is very dependent on the waveguide parameters, grating constant and the dielectric environment, and by tuning these parameters we obtain a theoretical sensitivity of 887 nm/RIU.

Efficient Monte Carlo simulation reveals significant multiple scattering errors in underwater angular scattering measurements.

Multiple scattering can severely affect the accuracy of optical instrumentation. Variance reduction methods have been implemented to improve a Monte Carlo model developed to simulate volume scattering functions measured by LISST-VSF instruments. The implemented methods can result in more than a tenfold increase in efficiency. The simulation is used to analyze multiple scattering errors for a range of Fournier-Forand (FF) phase functions. Our results demonstrate significant errors in the scattering coefficient, backscattering coefficient and phase function, where multiple scattering errors may only be considered negligible (<10%) for scattering coefficients <1 m-1. The errors depend strongly on the scattering coefficient but also increase when phase functions become more forward-peaked.

Analysis of multiple scattering errors in LISST-VSF volume scattering function measurements using Monte Carlo simulations and experimental data.

A Monte Carlo algorithm has been developed to investigate the effects of multiple scattering on the volume scattering function measured by the LISST-VSF instrument. The developed algorithm is compared to experimental results obtained from bench-top measurements using 508nm spherical polystyrene beads and Arizona test dust as scattering agents. The Monte Carlo simulation predicts measured volume scattering functions at all concentrations. We demonstrate that multiple scattered light can be a major contributor to the detected signal, resulting in errors in the measured volume scattering function and its derived inherent optical properties. We find a relative error of 10% in the scattering coefficient for optical depths ∼0.4, and it can reach 100% at optical depths ∼2.

Visualizing Borrelia burgdorferi Infection Using a Small-Molecule Imaging Probe.

In vivo diagnostic imaging of bacterial infections is currently reliant on targeting their metabolic pathways, an ineffective method to identify microbial species with low metabolic activity. Here, we establish HS-198 as a small-molecule fluorescent conjugate that selectively targets the highly conserved bacterial protein HtpG (high-temperature protein G), within Borrelia burgdorferi, the bacterium responsible for Lyme disease. We describe the use of HS-198 to target morphologic forms of B. burgdorferi in both the logarithmic growth phase and the metabolically dormant stationary phase as well as in inactivated spirochetes. Furthermore, in a murine infection model, systemically injected HS-198 identified B. burgdorferi as revealed by imaging in postnecropsy tissue sections. These findings demonstrate how small-molecule probes directed at conserved bacterial protein targets can function to identify the microbe using noninvasive imaging and potentially as scaffolds to deliver antimicrobial agents to the pathogen.

Blocking Borrelia burgdorferi transmission from infected ticks to nonhuman primates with a human monoclonal antibody.

Disrupting transmission of Borrelia burgdorferi sensu lato complex (B. burgdorferi) from infected ticks to humans is one strategy to prevent the significant morbidity from Lyme disease. We have previously shown that an anti-OspA human mAb, 2217, prevents transmission of B. burgdorferi from infected ticks in animal models. Maintenance of a protective plasma concentration of a human mAb for tick season presents a significant challenge for a preexposure prophylaxis strategy. Here, we describe the optimization of mAb 2217 by amino acid substitutions (2217LS: M428L and N434S) in the Fc domain. The LS mutation led to a 2-fold increase in half-life in cynomolgus monkeys. In a rhesus macaque model, 2217LS protected animals from tick transmission of spirochetes at a dose of 3 mg/kg. Crystallographic analysis of Fab in complex with OspA revealed that 2217 bound an epitope that was highly conserved among the B. burgdorferi, B. garinii, and B. afzelii species. Unlike most vaccines that may require boosters to achieve protection, our work supports the development of 2217LS as an effective preexposure prophylaxis in Lyme-endemic regions, with a single dose at the beginning of tick season offering immediate protection that remains for the duration of exposure risk.

Dietary patterns in the French adult population: a study from the second French national cross-sectional dietary survey (INCA2) (2006-2007).

Identification and characterisation of dietary patterns are needed to define public health policies to promote better food behaviours. The aim of this study was to identify the major dietary patterns in the French adult population and to determine their main demographic, socio-economic, nutritional and environmental characteristics. Dietary patterns were defined from food consumption data collected in the second French national cross-sectional dietary survey (2006-2007). Non-negative-matrix factorisation method, followed by a cluster analysis, was implemented to derive the dietary patterns. Logistic regressions were then used to determine their main demographic and socio-economic characteristics. Finally, nutritional profiles and contaminant exposure levels of dietary patterns were compared using ANOVA. Seven dietary patterns, with specific food consumption behaviours, were identified: 'Small eater', 'Health conscious', 'Mediterranean', 'Sweet and processed', 'Traditional', 'Snacker' and 'Basic consumer'. For instance, the Health-conscious pattern was characterised by a high consumption of low-fat and light products. Individuals belonging to this pattern were likely to be older and to have a better nutritional profile than the overall population, but were more exposed to many contaminants. Conversely, individuals of Snacker pattern were likely to be younger, consumed more highly processed foods, had a nutrient-poor profile but were exposed to a limited number of food contaminants. The study identified main dietary patterns in the French adult population with distinct food behaviours and specific demographic, socio-economic, nutritional and environmental features. Paradoxically, for better dietary patterns, potential health risks cannot be ruled out. Therefore, this study demonstrated the need to conduct a risk-benefit analysis to define efficient public health policies regarding diet.

Dietary patterns of French adults: associations with demographic, socio-economic and behavioural factors.

BACKGROUND: Although the French eating model may differ from those of other countries, no studies to date have investigated dietary patterns in a wide age range of adults and at the national level. We aimed to identify dietary patterns (DP) of French adults and assess their associations with demographic, socio-economic and behavioural factors. METHODS: The present study included 2624 adults (1087 men, 1537 women) aged 18-79 years from the cross-sectional national French INCA2 dietary survey. Dietary data were collected using a 7-day estimated food record. Clusters of DP were derived using principal component analysis and clustering, conjointly. Age-adjusted logistic regression analyses were used to investigate the association between DP and correlates. RESULTS: Five DP were identified, namely 'traditional', 'prudent', 'diversified', 'processed' and 'sandwiches'. Men were more likely to follow a traditional diet and women the 'prudent' pattern. Members of the 'processed' and 'sandwiches' patterns were younger compared to non-members. Healthier dietary patterns were overall positively associated with a higher socio-economic position, healthier behaviours (in terms of sedentary behaviours and smoking status) and lower body mass index. Under-reporting of energy intake, restrictive diet to lose weight and dietary supplement consumption were also related to specific DP, although differentially in men and women. Associations with contextual factors (i.e. household composition, agglomeration size and region) were also observed. CONCLUSIONS: The identification of adults' dietary patterns and associated behaviours (all modifiable) is important for the conceptualisation of multi-behavioural programs. The additional information on social and environmental correlates is also essential for targeting the most vulnerable population groups in the context of such public health interventions.

[Post-radiation atypical vascular lesions and angiosarcoma: 11 cases]. / Lésions vasculaires atypiques et angiosarcomes post-radiothérapie : 11 cas.

BACKGROUND: Post-radiation atypical vascular lesions of the skin display clinical and morphological overlap with well-differentiated angiosarcomas, and correct diagnosis may be difficult. PATIENTS AND METHODS: We studied clinical, histological and immuno-histochemical aspects (CD31, CD34, D2-40 and VEGFR-3) of eight post-radiation atypical vascular lesions comparatively with three post-radiation angiosarcomas. RESULTS: All patients were female and received radiation therapy for breast carcinoma. On average, atypical vascular lesions occurred 4.3 years after radiation therapy and presented as small papulonodules or erythematous plaques. The clinical course after simple excision was benign. Histologically, they were relatively circumscribed lesions and showed slit-like vessels dissecting dermal collagen in all cases. On average, angiosarcomas occurred 5 years after radiation therapy and presented as more extensive lesions with a more aggressive clinical course. The lesions showed histological overlap with atypical vascular lesions, but were poorly circumscribed, with deeper invasion, cytological atypia and mitosis. Although the immuno-histochemical profiles were similar, expression of VEGFR-3 was greater in two cases of angiosarcoma. CONCLUSION: Post-radiation atypical vascular lesions are benign lesions that display clinical, histological and immuno-phenotypic overlap with well-differentiated angiosarcoma, and diagnosis requires good clinicopathological correlation. VEGFR-3 may be useful for differential diagnosis, as well as amplification of the MYC gene.

Characterization of syk expression in human lung mast cells: relationship with function.

BACKGROUND: Previous studies indicate that the protein tyrosine kinase, syk, is critical in transducing FcɛRI-mediated signals. In human basophils, 'releasability' has been linked to the extent of syk expression. Human lung mast cells, like basophils, are also found to be variably responsive to IgE-dependent activation. OBJECTIVE: The aim of the present study was to determine whether the wide variability in human lung mast cell responses, following IgE-dependent activation, has a relationship with syk expression. METHODS: Mast cells were isolated from human lung tissue and 'releasability' was determined by activating the cells with a maximal releasing concentration of anti-IgE. Syk levels in mast cells were determined by immunoblotting and flow cytometry. RESULTS: Histamine release from mast cells, challenged with a maximal releasing concentration of anti-IgE, ranged from 0% to 69% (mean±SEM, 24±2%, n=53). A proportion of these preparations (nine out of 53) released very low levels of histamine (5%) in response to anti-IgE. Flow cytometry of a subset of preparations indicated that a weak response to anti-IgE was not related to a lack of surface IgE. Immunoblotting and flow cytometry studies demonstrated that, compared with mononuclear cells, human lung mast cells express low and variable levels of syk. However, there was no correlation between syk expression and mast cell releasability. Nonetheless, a number of putative inhibitors of syk including NVP-QAB205 (EC50, 0.2 µm) effectively attenuated the IgE-dependent release of histamine from mast cells. CONCLUSION AND CLINICAL RELEVANCE: These studies indicate that although syk may play an important role in mediating degranulation, the relative level of syk expression does not govern human lung mast cell releasability. Identification of the mechanisms that govern IgE-dependent activation of human lung mast cells is likely to be of wider clinical significance, given the central role that mast cells play in the development of allergic asthma.

Asthma attacks and deprivation: gradients in use of mobile emergency medical services.

BACKGROUND: To test whether rates of emergency telephone calls for asthma attacks are associated with contextual socioeconomic deprivation in the Strasbourg metropolitan area (France). METHODS: Two mobile emergency medical service networks provided all data for 2000-2005 about emergency calls for asthma attacks, georeferenced by census block. Contextual deprivation was measured for each census block by a composite index, constructed by principal component analysis. Emergency call rates were calculated for each census block and for different age groups. Empirical Bayesian smoothing was used to reduce the instability of outlying rates. RESULTS: Positive spatial autocorrelation was detected in both the health and the socioeconomic datasets. In all age groups, rates of calls for asthma attacks increased linearly with deprivation. Correlation coefficients between these two factors varied according to age group: 0.53 for the group aged 0-9 years, 0.46 for 10-19 years, 0.65 for 20-39 years, 0.70 for 40-64 years, 0.68 for 65 and older, and 0.77 for the age-standardised incidence ratio. These correlation coefficients were highly significant (p<0.01), even after spatial autocorrelation was taken into account. CONCLUSION: The socioeconomic gradients observed are consistent with those observed for severe forms of asthma and asthma hospitalisations in Western countries.

Acylated anthocyanins from leaves of Oxalis triangularis.

The novel anthocyanins, malvidin 3-O-(6-O-(4-O-malonyl-alpha-rhamnopyranosyl)-beta-glucopyranoside)-5-O-beta-glucopyranoside (2), malvidin 3-O-(6-O-alpha-rhamnopyranosyl-beta-glucopyranoside)-5-O-(6-O-malonyl-beta-glucopyranoside) (3), malvidin 3-O-(6-O-(4-O-malonyl-alpha-rhamnopyranosyl)-beta-glucopyranoside)-5-O-(6-O-malonyl-beta-glucopyranoside) (4), malvidin 3-O-(6-O-(4-O-malonyl-alpha-rhamnopyranosyl)-beta-glucopyranoside) (5) and malvidin 3-O-(6-O-(Z)-p-coumaroyl-beta-glucopyranoside)-5-O-beta-glucopyranoside (6), in addition to the 3-O-(6-O-alpha-rhamnopyranosyl-beta-glucopyranoside)-5-O-beta-glucopyranoside (1) and the 3-O-(6-O-(E)-p-coumaroyl-beta-glucopyranoside)-5-O-beta-glucopyranoside (7) of malvidin have been isolated from purple leaves of Oxalis triangularis A. St.-Hil. In pigments 2, 4 and 5 a malonyl unit is linked to the rhamnose 4-position, which has not been reported previously for any anthocyanin before. The identifications were mainly based on 2D NMR spectroscopy and electrospray MS.

Failure of isotretinoin and interferon-alpha combination therapy for HPV-linked severe vulvar dysplasia. A report of two cases.

BACKGROUND: Retinoids (RA) and interferon (IFN) have been reported to be active against a variety of tumors and human papillomavirus (HPV)-related lesions. Because chronic and recurrent HPV-linked vulvar intraepithelial neoplasia 3 (VIN 3) have a high risk of invasion, we evaluated combined therapy of IFN-alpha with 13-cis-retinoic acid (13 cRA) in the treatment of two VIN 3 cases of this type. CASE: Two patients with chronic and recurrent VIN 3 were treated with combined therapy of IFN-alpha (4.5 x 10(6) five times a week) and 13 cRA (1 mg/kg/d) for six months. Clinical regression was observed at the end of treatment in both cases, but histologic features of VIN 3 were still present. CONCLUSION: These data demonstrate the ineffectiveness of the combined regimen of IFN-alpha and 13 cRA with this schedule for a period of six months in recurrent and chronic VIN 3.

Prospective study of the incidence of melanoma in the Paris region in 1994. The PETRI Melanoma Group.

The aim of this study was to estimate the incidence of melanoma in the Paris region in 1994 and analyse the main clinical and histological characteristics of these lesions. It took the form of a prospective inquiry, mailed to public and private pathology laboratories, to count as accurately as possible the number of new cases diagnosed by pathologists in the region during the 1994 calendar year. In all, 1089 newly diagnosed Clark level I to V melanomas (excluding precancerous melanosis of Dubreuilh) were studied. Parameters recorded included age, sex, Clark level and Breslow's thickness. The incidence per 100,000 inhabitants was 9.93 for melanoma and 8.62 for invasive melanoma. The female to male ratio was 1.6. Clark level I or thin (< 0.75 mm) melanomas represented 64.8% of the lesions. At the time of diagnosis, the females were significantly younger than the males (P = 0.004). Breslow's thickness increased with age and was significantly lower in women (P = 0.00005), especially those between 40 and 49 years old. The incidence of melanoma in the Paris region in 1994 was close to that observed during the preceding 5 years in England, Scotland and the French department of Haut-Rhin. It was 2.32 times higher for males and 1.69 times higher for females than the rates estimated for France for the period 1978-1982.

Herpesvirus-like DNA sequences in patients with Mediterranean Kaposi's sarcoma.

DNA sequences closely related to herpesvirus-like sequences have been found in AIDS-associated Kaposi's sarcoma. Using PCR, we found herpesvirus-like DNA sequences in Kaposi's lesions and normal adjacent skin in five patients with Mediterranean Kaposi's sarcoma. We did not find these sequences in tissues from patients without Kaposi's sarcoma. Semi-quantitative PCR revealed many more herpesvirus-like sequences in Kaposi's lesions than in unaffected skin. Our results reinforce the hypothesis that an infectious agent closely related to gamma-herpesvirus is implicated in the pathogenesis of Mediterranean and AIDS-associated Kaposi's sarcoma.

[Proteus syndrome. 8 cases]. / Syndrome Protée: huit cas.

INTRODUCTION: Proteus syndrome most often includes: corporal hemi-hypertrophia, gigantism of the extremities with hyperplasia of the palms and soles, vascular abnormalities and varied types of other hamartomatous tumours. The dysmorphic growth generates functional orthopaedic and orthognatic disabilities that increase with age. OBSERVATIONS: We report, on eight cases, our experience in management of Proteus syndrome abnormalities and the benefits of new techniques in imaging and interventional vascular radiology. The correction of limb orthopaedic abnormalities is complicated with elephantiasic enlargement of soft tissues. In some patients the absence of a deep venous network contra-indicates transcutaneous occlusion of dysplatic vessels. Facial asymmetry and orthognatic anomalies are better managed after permanent teeth have appeared. COMMENTARIES: The management of these disabilities is carried out by staff of different specialities but should be organized by a practitioner who regularly follows the child and detects early the functional disturbances. Aesthetic corrections are performed later.

Granulomatous cheilitis in two children with sarcoidosis.

Sarcoidosis is rare in children, who usually have only asymptomatic pulmonary involvement. We report granulomatous cheilitis in two children with sarcoidosis. Both children had systemic sarcoidosis with lymph node and pulmonary involvement.