Segmentation of Plantar Foot Thermal Images Using Prior Information.

Diabetic foot (DF) complications are associated with temperature variations. The occurrence of DF ulceration could be reduced by using a contactless thermal camera. The aim of our study is to provide a decision support tool for the prevention of DF ulcers. Thus, the segmentation of the plantar foot in thermal images is a challenging step for a non-constraining acquisition protocol. This paper presents a new segmentation method for plantar foot thermal images. This method is designed to include five pieces of prior information regarding the aforementioned images. First, a new energy term is added to the snake of Kass et al. in order to force its curvature to match that of the prior shape, which has a known form. Second, we defined the initial contour as the downsized prior-shape contour, which is placed inside the plantar foot surface in a vertical orientation. This choice makes the snake avoid strong false boundaries present outside the plantar region when evolving. As a result, the snake produces a smooth contour that rapidly converges to the true boundaries of the foot. The proposed method is compared to two classical prior-shape snake methods, that of Ahmed et al. and that of Chen et al. A database of 50 plantar foot thermal images was processed. The results show that the proposed method outperforms the previous two methods with a root-mean-square error of 5.12 pixels and a dice similarity coefficient of 94%. The segmentation of the plantar foot regions in the thermal images helped us to assess the point-to-point temperature differences between the two feet in order to detect hyperthermia regions. The presence of such regions is the pre-sign of ulcers in the diabetic foot. Furthermore, our method was applied to hyperthermia detection to illustrate the promising potential of thermography in the case of the diabetic foot. Associated with a friendly acquisition protocol, the proposed segmentation method is the first step for a future mobile smartphone-based plantar foot thermal analysis for diabetic foot patients.

Parasite prevalence in fecal samples from shelter dogs and cats across the Canadian provinces.

BACKGROUND: In Canada, surveys of enteric parasites in dogs and cats have been reported sporadically over the past 40 years, mostly focusing on a specific region. The present work was performed to determine the current prevalence of various parasites in fecal samples from shelter dogs and cats across the Canadian provinces. METHODS: A total of 1086 dog and 636 cat fecal samples from 26 shelters were analysed using a sugar solution double centrifugal flotation technique. Prevalences (national, regional, provincial, age and parasite-specific), were calculated and compared using the Fisher-Exact test. A multiplex PCR was performed to distinguish Taenia spp, Echinococcus granulosus and E. multilocularis on samples positive for taeniid eggs. RESULTS: Overall, 33.9% of dogs and 31.8% of cats were positive for at least one parasite. Toxocara canis and T. cati were the most prevalent parasite present in fecal samples followed by Cystoisospora spp. Prevalence in dogs was similar across the Atlantic, East, West and Pacific regions, while prevalence in cats varied regionally. Eggs of E. granulosus/E. canadensis were detected in samples from dogs from BC, AB, and ON. CONCLUSIONS: Data from this study will help in the development of strategies, based on the level of risk per geographic location for the prevention and response to these parasites in pets and free-roaming and shelter animals in Canada.

Survey of Giardia and Cryptosporidium in lemurs from the Ranomafana National Park, Madagascar.

We detected Cryptosporidium sp. by direct immunofluorescence in fecal samples from greater bamboo lemurs (Prolemur simus) and eastern rufous mouse lemurs (Microcebus rufus) inhabiting the Ranomafana National Park, Madagascar. This is the first report of an occurrence of these potentially zoonotic parasites in free-ranging lemurs in the rain forest of Madagascar.

Seroprevalence of Borrelia burgdorferi, Anaplasma phagocytophilum, Ehrlichia canis, and Dirofilaria immitis among dogs in Canada.

The seropositivity of dogs to Borrelia burgdorferi, Anaplasma phagocytophilum, and Ehrlichia canis antibodies, and Dirofilaria immitis antigen was assessed in Canada. Borrelia burgdorferi had the highest seroprevalence, while that of Dirofilaria immitis has not changed significantly in the past 20 y. The risk for these vector-borne infectious agents in Canadian dogs is low but widespread with foci of higher prevalence.

Does examination of fecal samples 24 hours after cestocide treatment increase the sensitivity of Anoplocephala spp. detection in naturally infected horses?

Fecal samples were examined immediately before and 24 to 48 h after cestocide treatment for a comparative detection of tapeworm-positive horses. In early winter, 17 weanlings, 20 yearlings, 15 2-year-old horses, 24 breeding mares, and 2 stallions were treated with praziquantel in combination with a macrocyclic lactone. The horses were presumed to be naturally infected with tapeworms after pasture grazing. Fecal samples were collected before treatment (Day 0), at 24 or 48 h after treatment (Day 1-2), and 16 to 21 d after treatment (Day 16-21). A Wisconsin test was done on all fecal samples. Odds of detection of infection for all age groups increased by a factor of 2.04 [95% confidence interval (CI): 1.30 to 3.20] from Day 0 to Day 1-2 (P = 0.002).

Coherent anti-Stokes Raman scattering hyperspectral tissue imaging with a wavelength-swept system.

We present a wavelength-swept coherent anti-Stokes Raman scattering (WS-CARS) spectroscopy system for hyperspectral imaging in thick tissue. We use a strategy where the Raman lines are excited sequentially, circumventing the need for a spectrometer. This fibre laser system, consisting of a pump laser synchronized with a rapidly tunable programmable laser (PL), can access Raman lines over a significant fraction of the high wavenumber region (2700-2950 cm(-1)) at rates of up to 10,000 spectral points per second. To demonstrate its capabilities, we have acquired WS-CARS spectra of several samples as well as images and hyperspectral images (HSI) of thick tissue both in forward and epi-detection. This instrument should be especially useful in providing local biochemical information with surrounding context supplied by imaging.

Comparative long-term efficacy of ivermectin and moxidectin over winter in Canadian horses treated at removal from pastures for winter housing.

The impact of a late fall treatment on the spring rise of fecal egg counts was evaluated in a controlled study with Canadian horses treated with 2 different dewormers immediately after removal from pasture for winter housing. The horses were stabled until the end of the trial period. Seventeen weanlings, 20 yearlings, and 15 2-year-old horses located in Ontario, which were presumed to be naturally infected with cyathostomins after pasture grazing, were randomly allocated to either a group treated with 0.4 mg/kg of moxidectin and 2.5 mg/kg of praziquantel or a group treated with 0.2 mg/kg of ivermectin and 1.5 mg/kg of praziquantel. Three weeks after treatment, all strongyle fecal egg counts were reduced to zero for both treatment groups. However, at 5 months post-treatment, mean geometric fecal egg counts were statistically higher for the yearlings and 2-year-old horses treated with ivermectin than for the yearlings and 2-year-old horses treated with moxidectin (P < 0.0001).

Photosensitivity of As2S3 chalcogenide thin films at 1.5 microm.

Chalcogenide glasses are promising candidates for all-optical switching and various nonlinear applications. However, we show that As2S3 thin films are photosensitive at wavelengths in the 1.5-microm telecommunication window. This sensitivity is evidenced by the formation of self-written waveguides in slabs, where channels as narrow as 1 microm are created. We also show the detrimental effects of such photosensitivity in ridge waveguides. This photosensitivity seems to occur only in thin-film form and not in bulk samples or fibers.