A discontinuous extended Kalman filter for non-smooth dynamic problems

Problems that result into locally non-differentiable and hence non-smooth state-space equations are often encountered in engineering. Examples include problems involving material laws pertaining to plasticity, impact and highly non-linear phenomena. Estimating the parameters of such systems poses a challenge, particularly since the majority of system identification algorithms are formulated on the basis of smooth systems under the assumption of observability, identifiability and time invariance. For a smooth system, an observable state remains observable throughout the system evolution with the exception of few selected realizations of the state vector. However, for a non-smooth system the observable set of states and parameters may vary during the evolution of the system throughout a dynamic analysis. This may cause standard identification (ID) methods, such as the Extended Kalman Filter, to temporarily diverge and ultimately fail in accurately identifying the parameters of the system. In this work, the influence of observability of non-smooth systems to the performance of the Extended and Unscented Kalman Filters is discussed and a novel algorithm particularly suited for this purpose, termed the Discontinuous Extended Kalman Filter (DEKF), is proposed

Update on insulin treatment of dogs and cats with non-complicated diabetes mellitus

Diabetes mellitus is a common endocrine disease of dogs and cats. Treatment is mainly based on insulin administration and dietary modifications. The aim of this review is to provide updated information on insulin treatment of dogs and cats with non-complicated diabetes mellitus. During the last years, there has been significant progress in the management of this disease, thanks to the use of long-acting insulin preparations that do not cause pronounced fluctuations of blood glucose concentrations (insulin glargin and dctemir) and because of the widespread use of home glucose monitoring by the owners of diabetic pets. Home glucose monitoring is based on capillary blood sampling from the ear pinnae or the foot pad and measurement of blood glucose concentration with a portable blood glucose meter. This can be done periodically (e.g. every week) to replace the traditional in-clinic blood glucose curve; in this case, blood glucose concentration is measured just before the morning insulin administration and then every 1-2 hours until the next dose (usually for 12 hours). Furthermore, especially for the cat, home glucose monitoring can be performed 3-5 times per day. on a daily basis, in order to safely adjust insulin dose and achieve tight control of hyperglycemia (i.e. blood glucose concentration between 50 and 200 mg dl-1 throughout the day). The combination of dietary management. of insulin glargine or dctemir administration and of the tight control of hyperglycemia has substantially increased the proportion of cats that enter into temporal or permanent diabetic remission and can be further managed without insulin. Another important achievement is the use of continuous glucose monitoring systems to monitor interstitial fluid glucose concentrations. These devices can be used in the clinic and at home and they can measure glucose concentration every 5 minutes for up to 72 consecutive hours, thus facilitating optimal adjustment of insulin treatment

An efficient algorithm to test the observability of rational nonlinear systems with unmeasured inputs

This work proposes an efficient algorithm to examine the observability and identifiability of rational nonlinear systems in the presence of unmeasured and unknown inputs. The proposed algorithm allows for determining whether the dynamic states, unknown parameters and unmeasured inputs of a dynamical system can be, in theory, successfully identified from a given set of input–output measurements. The underlying theory of the algorithm is based on a further extension of the recently suggested extended Observability Rank Condition while focusing on rational instead of analytic nonlinearities. For the robust development of the algorithm, a power series based framework is established for computing the observability matrix efficiently. The occurring framework substantially alleviates the computational burden of the standard implementations of the extended Observability Rank Condition approaches, which allows for applications to real-world engineering systems that are often large and complex. Several examples of large-scale and high-complexity engineering structures are used to demonstrate the performance and capability of the algorithm. Furthermore, the proposed algorithm is used to investigate the feasibility of monitoring a sub-system that is independently separated from a full system under the introduction of additional unmeasured inputs.The first author would like to gratefully acknowledge the financial support from the China Scholarship Council (CSC) for his Ph.D. studies

Editorial: Robust Monitoring, Diagnostic Methods and Tools for Engineered Systems

[No abstract available

A field trial of a fixed combination of permethrin and fipronil (Effitix®) for the treatment and prevention of flea infestation in dogs living with sheep

Background: A large number of fleas parasitize dogs living with sheep in Greece. The primary aim of this randomized, blinded, placebo-controlled trial was to examine the efficacy of a permethrin-fipronil combination (Effitix®) for the treatment and prevention of flea infestation in dogs living with sheep and the secondary aim was to examine the efficacy of this intervention on flea infestation, pruritus and skin lesions of the people in contact with these dogs. Methods: Thirty dogs living with sheep and infested by at least 10 fleas and all 80 sheep living on the same premises were randomly allocated into equal groups. Group A dogs were treated three times, every 4 weeks, with a spot-on containing 54.5% permethrin and 6.1% fipronil, group A sheep were treated, on the same days, with a pour-on containing 1% deltamethrin, whereas group B dogs were sham-treated and group B sheep were placebo-treated. Flea counting was performed at the beginning of the trial (day 0) and after 14, 28, 56 and 84 days and the first five fleas from each animal were used for species identification. At the same time points, flea infestation, pruritus and skin lesions of the people in contact with the dogs were assessed. Results: The percentage of dogs with zero flea counts was significantly higher in group A than in group B on days 14, 28, 56 and 84 and flea counts were significantly lower in group A dogs than in group B dogs at the same time points. The percent efficacy of the permethrin-fipronil combination was higher than 78% (arithmetic means) or than 96% (geometric means) throughout the study. No adverse reactions were recorded. Between the two flea species found on dogs, Ctenocephalides canis was predominant over C. felis. Flea-infected sheep were not found at the beginning or during the study and no significant changes in flea infestation, pruritus and skin lesions of the people in contact with the dogs were witnessed throughout the study. Conclusions: A spot-on solution containing 54.5% permethrin and 6.1% fipronil is safe and effective for the treatment and prevention of C. canis and C. felis infestations in dogs living with sheep. © 2017 The Author(s)

Repeatability and reproducibility of the interpretation of intradermal test results in dogs with atopic dermatitis

Background – There is lack of studies evaluating the repeatability and reproducibility of the interpretation of intradermal testing in dogs with atopic dermatitis (AD). Objectives – To evaluate the repeatability and reproducibility of the interpretation of intradermal test results in dogs with AD. For comparison, the repeatability of allergen-specific immunoglobulin (Ig)E serology also was examined. Materials and methods – Twenty dogs with AD were used. Intradermal test included injections of known negative and positive controls, and of 25 masked injections of 10 allergens/controls, that were selected randomly and injected at random positions. Reactions to the 25 masked allergens/controls were scored (positive/negative) subjectively by three independent examiners followed by an objective assessment. Allergen-specific IgE serology was performed in blinded duplicate samples collected from all dogs for nine of 10 of the same allergens. Results – Kappa values of intraobserver repeatability (≥2 injections of the same allergen to different positions of the same dog) varied between −0.53 and 0.8 (subjective evaluations), and between 0.03 and 1 (objective evaluation). When the repeatability of the serological test was examined k = 0.91. Kappa values for the interobserver reproducibility (objective and three subjective evaluations of the same allergen injected at the same position of the same dog) varied between 0.6 and 0.74 (overall 0.67). Conclusions and clinical relevance – Intraobserver repeatability of the subjective and objective evaluation of IDT results varied from good to poor and depended on the number of times the same allergen was injected, whereas interobserver reproducibility varied from substantial to moderate. Further studies are needed to optimise the repeatability and reproducibility of IDT in dogs. © 2022 ESVD and ACVD

Serum cobalamin concentrations in dogs with leishmaniosis before and during treatment

Hypocobalaminemia in dogs is most commonly associated with gastrointestinal disorders leading to impaired absorption and utilization of cobalamin. The objectives of this study were to compare serum cobalamin concentrations between dogs with leishmaniosis and clinically healthy dogs, and to assess possible alterations of serum cobalamin concentrations in dogs with leishmaniosis at different timepoints during treatment. Fifty-five dogs with leishmaniosis and 129 clinically healthy dogs were prospectively enrolled. Diagnosis of leishmaniosis was based on clinical presentation, positive serology and microscopic detection of Leishmania amastigotes in lymph node aspiration smears. Twenty of the dogs with leishmaniosis were treated with a combination of meglumine antimonate and allopurinol for 28 days and serum cobalamin concentrations were measured in blood samples that were collected before initiation of treatment (timepoint 0) and on days 14 and 28. In order to estimate alterations of serum cobalamin concentrations during treatment, cobalamin concentrations were measured in blood samples from 20 out of 55 dogs with leishmaniosis at all timepoints. Serum cobalamin concentrations were significantly lower in dogs with leishmaniosis before treatment (median: 362 ng/L; IQR: 277−477 ng/L) compared to clinically healthy dogs (median: 470 ng/L; IQR: 367−632 ng/L; P = 0.0035). Serum cobalamin concentrations increased significantly in dogs with leishmaniosis on day 14 of treatment compared to timepoint 0 (P = 0.02). In the present study, serum cobalamin concentrations were significantly lower in dogs with leishmaniosis compared to clinically healthy dogs. In addition, there was an increase in serum cobalamin concentrations during treatment. The clinical significance of hypocobalaminemia in dogs with leishmaniosis remains to be determined. © 2021 Elsevier Lt

Molecular detection of vector-borne pathogens in Greek cats

Infectious diseases have been increasingly recognized in cats worldwide. The objective of this study was the molecular investigation of the prevalence of selected pathogens in healthy and sick cats from Greece, a country highly endemic for several canine vector-borne pathogens. Blood and/or bone marrow samples from 50 clinically healthy and 50 sick adult (>1 year-old) cats were retrospectively examined for the amplification of Bartonella spp., haemoplasmas, Ehrlichia spp., Anaplasma spp., Babesia spp., and Cytauxzoon spp. DNA. Overall, 14.9% of the cats were found to be infected or co-infected by haemoplasmas, including Candidatus Mycoplasma haemominutum and M. haemofelis. In addition, 8.5% of the cats were infected by Bartonella henselae, Bartonella clarridgeiae or Bartonella koehlerae. In contrast, DNA of Ehrlichia spp., Anaplasma spp., Babesia spp. and Cytauxzoon spp. was not amplified from the blood or bone marrow of any cat. There was no significant difference in either haemoplasma or Bartonella infection rates when comparing healthy and sick cats. This study represents the first description of Bartonella koehlerae in Greek cats. © 2017 Elsevier Gmb

Evaluation of clinicopathological abnormalities in sick cats naturally infected by Leishmania infantum

Feline infection by Leishmania infantum (syn. L. chagasi) has been described in areas where canine leishmaniosis is endemic. A wide variety of clinicopathological abnormalities have been reported in cats presenting clinical signs of leishmaniosis but there is a paucity of information regarding cats infected by L. infantum that do not suffer from leishmaniosis but from other diseases. The aim of this study was to compare: a) the frequency of clinicopathological abnormalities and b) the values of hematology, serum biochemistry and urinalysis parameters, between non-infected sick cats and sick cats that were infected by L. infantum. A total of 50 cats with cutaneous, ocular and/or systemic clinical signs that lived in an endemic area and had been tested for infection by L. infantum using PCR from four different tissues, were included. Based on the results of PCR, 20/50 cats were found to be infected and 30/50 non-infected. The only difference between the two groups of cats was that the concentration of inorganic phosphorus (P = 0.043) was higher in infected cats. This finding may suggest an association between infection by L. infantum and feline kidney disease. © 2020CAT, Clinicopathological abnormalities, Leishmania infantum, Phosphorus, Kidney disease, Parasite, Leishmania, Veterinary medicine, Infectious disease, Parasitology © 202

Are stray dogs confined in animal shelters at increased risk of seropositivity to Leishmania infantum? A case control study

The aim of this study was to compare the risk of seropositivity between stray dogs and privately-owned dogs living in the same endemic area. Sixty-seven stray (group A) and 115 privately-owned (group B) dogs were enrolled. History, physical examination findings and results of serology, haematology and total solids were compared between groups and between seropositive group A and seropositive group B dogs. Variables with p value ≤0.2 were used to build two multivariable models using results of serology as the dependent variable: the first model included the group and historical information, whereas the second included the group, physical examination and results of haematology and total solid measurement. Stray dogs had 4.59-fold and 3.72-fold higher risk of seropositivity compared with privately-owned dogs in the first and second model, respectively. Additional factors associated with positive serology included female sex, not sampling during transmission period, masticatory muscle atrophy, footpad hyperkeratosis, low haematocrit and low platelet count. In conclusion, stray dogs were at higher risk of seropositivity