A new optical freezing array for the study of heterogeneous ice nucleation in microliter-sized droplets is introduced, tested and applied to the study of immersion freezing in aqueous Snomax® ...suspensions. In the Bielefeld Ice Nucleation ARraY (BINARY) ice nucleation can be studied simultaneously in 36 droplets at temperatures down to −40 °C (233 K) and at cooling rates between 0.1 and 10 K min−1. The droplets are separated from each other in individual compartments, thus preventing a Wegener–Bergeron–Findeisen type water vapor transfer between droplets as well as avoiding the seeding of neighboring droplets by formation and surface growth of frost halos. Analysis of freezing and melting occurs via an automated real-time image analysis of the optical brightness of each individual droplet. As an application ice nucleation in water droplets containing Snomax® at concentrations from 1 ng mL−1 to 1 mg mL−1 was investigated. Using different cooling rates, a small time dependence of ice nucleation induced by two different classes of ice nucleators (INs) contained in Snomax® was detected and the corresponding heterogeneous ice nucleation rate coefficient was quantified. The observed time dependence is smaller than those of other types of INs reported in the literature, suggesting that the BINARY setup is suitable for quantifying time dependence for most other INs of atmospheric interest, making it a useful tool for future investigations.
The echinococcoses are chronic, parasitic diseases that are acquired after ingestion of infective taeniid tapeworm eggs from certain species of the genus Echinococcus. Cystic echinococcosis (CE) ...occurs worldwide, whereas, alveolar echinococcosis (AE) is restricted to the northern hemisphere, and neotropical echinococcosis (NE) has only been identified in Central and South America. Clinical manifestations and disease courses vary profoundly for the different species of Echinococcus. CE presents as small to large cysts, and has commonly been referred to as 'hydatid disease', or 'hydatidosis'. A structured stage-specific approach to CE management, based on the World Health Organization (WHO) ultrasound classification of liver cysts, is now recommended. Management options include percutaneous sterilization techniques, surgery, drug treatment, a 'watch-and-wait' approach or combinations thereof. In contrast, clinical manifestations associated with AE resemble those of a 'malignant', silently-progressing liver disease, with local tissue infiltration and metastases. Structured care is important for AE management and includes WHO staging, drug therapy and long-term follow-up for at least a decade. NE presents as polycystic or unicystic disease. Clinical characteristics resemble those of AE, and management needs to be structured accordingly. However, to date, only a few hundreds of cases have been reported in the literature. The echinococcoses are often expensive and complicated to treat, and prospective clinical studies are needed to better inform case management decisions.
Seven different instruments and measurement methods were used to examine the immersion freezing of bacterial ice nuclei from Snomax® (hereafter Snomax), a product containing ice-active protein ...complexes from non-viable Pseudomonas syringae bacteria. The experimental conditions were kept as similar as possible for the different measurements. Of the participating instruments, some examined droplets which had been made from suspensions directly, and the others examined droplets activated on previously generated Snomax particles, with particle diameters of mostly a few hundred nanometers and up to a few micrometers in some cases. Data were obtained in the temperature range from −2 to −38 °C, and it was found that all ice-active protein complexes were already activated above −12 °C. Droplets with different Snomax mass concentrations covering 10 orders of magnitude were examined. Some instruments had very short ice nucleation times down to below 1 s, while others had comparably slow cooling rates around 1 K min−1. Displaying data from the different instruments in terms of numbers of ice-active protein complexes per dry mass of Snomax, nm, showed that within their uncertainty, the data agree well with each other as well as to previously reported literature results. Two parameterizations were taken from literature for a direct comparison to our results, and these were a time-dependent approach based on a contact angle distribution (Niedermeier et al., 2014) and a modification of the parameterization presented in Hartmann et al. (2013) representing a time-independent approach. The agreement between these and the measured data were good; i.e., they agreed within a temperature range of 0.6 K or equivalently a range in nm of a factor of 2. From the results presented herein, we propose that Snomax, at least when carefully shared and prepared, is a suitable material to test and compare different instruments for their accuracy of measuring immersion freezing.
The Ostwald ripening of polycrystalline ice in aqueous sucrose solutions was investigated experimentally. The kinetics of this ice recrystallization process was studied at temperatures between −6 and ...−10 °C and varying ice volume fractions. Using the theory of Lifshitz, Slyozov, and Wagner (LSW), the diffusion-limited rate constant for ice recrystallization was determined. Also, the effects of synthetic analogues of natural antifreeze glycoproteins (AFGP) were studied. These analogues synAFGPmi (i = 3−5) contained monosaccharide side groups instead of disaccharide side groups that occur in natural AFGP. In order to account for the inhibition effect of the synAFGPmi, we have modified classical LSW theory, allowing for the derivation of inhibition rate constants. It was found that the investigated synAFGPmi inhibit ice recrystallization at concentrations down to ∼3 μg mL−1 or, equivalently, ∼1 μmol L−1 for the largest synAFGPmi investigated: synAFGPm5. Hence, our new method is capable of quantitatively assessing the efficiency of very similar AFGP with a sensitivity that is at least 2 orders of magnitude larger than that typical for quantitative thermal hysteresis measurements.
This review presents the historical and current situation of echinococcoses in Mongolia. Since the collapse of the Soviet Union in 1991, Mongolia's health surveillance infrastructure has been very ...poor, especially as it pertains to chronic diseases, including neglected zoonotic diseases (NZDs). Although there is anecdotal evidence of people dying from hepatic disease due to infection with the larval stage of Echinococcus spp., there are very few published reports. All confirmed cases of echinococcoses in Mongolia are from hospitals located in the capital city of Ulaanbaatar. Cases of cystic echinococcosis (CE), caused by either Echinococcus granulosus sensu stricto or Echinococcus canadensis are believed to be relatively common throughout Mongolia. In contrast, cases of alveolar echinococcosis (AE), caused by Echinococcus multilocularis, are believed to be rare. Recent wild-animal surveys have revealed that wolves (Canis lupus) are the major definitive hosts of E. canadensis, whereas both wolves and red foxes (Vulpes vulpes) are the primary definitive hosts of E. multilocularis. Although wild-animal surveys have begun to elucidate the transmission of Echinococcus spp. in Mongolia, there have yet to be large-scale studies conducted in domestic dogs and livestock. Therefore, further epidemiological studies, in addition to education-based control campaigns, are needed to help combat this NZD.
Cystic echinococcosis (CE) is a zoonotic disease caused by the larval stage of
tapeworms. These parasites have a worldwide geographic distribution and pose a serious threat to livestock industry as ...well as human health in the endemic areas. CE is widely distributed in Pakistan. However, very few reports are available related to the regional transmission of
. A retrospective analysis was conducted of surgically confirmed CE patients who were treated at Shoukat Khanum Memorial Cancer Hospital and Research Centre in Lahore, Punjab Province, Pakistan from 2007 – 2018. In total, 536 CE patients were evaluated during the study period. Cases originated from the provinces of Khyber Pakhtunkhwa (n=336), Punjab (n=147), Baluchistan (n=18), Sindh (n=3), Islamabad (n=2), Gilgit Baltistan (n=1), and Azad Jammu and Kashmir (n=1). An additional 28 cases were from Afghanistan. The highest number of CE cases was reported in 2013 (n=90). Females made up a larger proportion of cases (n=310; 57.8 %) than males (n=226; 42.2 %). Most patients were members of the Pashtun (n=197; 36.7 %), Hindku (n=142; 26.5 %), and Punjabi (n=118; 22.0 %) ethnic groups. The largest number of cysts was obtained from the liver (137/536; 25.6 %). This study showed that CE is likely present throughout Pakistan. In order to control the disease, a comprehensive control program and regional surveillance are needed.
Background
Cerebral microbleeds (CMBs) are focal intraparenchymal signal voids on gradient‐echo magnetic resonance imaging (MRI), corresponding to regions of chronic hemorrhage. In humans, they are ...associated with systemic disease and shorter survival times. Although similar findings have been identified in dogs, their epidemiology and clinical correlations have not been investigated.
Objective
To determine epidemiological features, clinical associations, and associations with outcome for putative CMB‐like foci (putative microbleeds pMBs) identified by T2*‐weighted MRI in dogs.
Animals
Five hundred and eighty‐two dogs undergoing 3T brain MRI between 2011 and 2016.
Methods
Retrospective case–control study. Demographic, diagnostic, and clinicopathological data were obtained from medical records and phone follow‐up. Demographic variables were compared between dogs with and without evidence of pMBs. For dogs with such evidence, and a subset of matched controls, associations with clinical presentation, concurrent disease, and survival times were evaluated.
Results
Dogs with pMBs were older (P < .001) and smaller (P = .004) than unaffected dogs. Compared to matched controls, they presented more frequently for vestibular signs (P = .030). Cortical atrophy occurred concurrently with pMBs in 26% (14/54) of dogs. Diagnosed renal disease was not significantly associated with pMBs, but proteinuria was more common in dogs with pMBs than in matched controls (odds ratio = 3.01, P = .005). Dogs with pMBs had a shorter median survival time than did matched controls (P = .011).
Conclusions and Clinical Importance
Putative microbleeds occurred in 54 of 582 (9.3%) of dogs undergoing brain MRI, but may not be a normal consequence of aging. They were associated with shorter survival time and proteinuria in the study population.
This review aims to summarise some of the recent studies that have been undertaken on parasites of the genus
Echinococcus and the diseases which they cause. Although the adult parasite, which ...inhabits the intestine of various carnivore species is not pathogenic, the larval or metacestode stages can be highly pathogenic, causing economic losses to livestock and various forms of echinococcosis in humans, some of which have a high fatality rate. There is growing evidence that there are at least 5 species of
Echinococcus rather than the generally accepted 4 species. Within these species there are a number of genotypes or strains. This can have implications for surveillance and control. In some wealthy countries, cystic echinococcosis caused by
Echinococcus granulosus has been successfully controlled or indeed eradicated. However, in most parts of the world it remains a serious threat to human health. In the former Soviet Union, the disease has rapidly increased in incidence after the end of communist administration. Human alveolar echinococcosis, caused by
Echinococcus multilocularis, is more sporadic. However, in some Chinese communities there is a disturbingly high human prevalence and in Europe there has been an increase in the detection rate of
E. multilocularis in animals in the last 10 years. Echinococcosis can present diagnostic challenges, particularly in the definitive host in areas of low endemicity. Much of the recent work relating to the use of coproantigen and PCR to overcome these difficulties is summarized. New ideas for controlling the parasite are becoming available and these include both the use of vaccination and the application of mathematical models to determine the most cost effective means of control. Effective measures that are affordable are vital if the parasite is to be controlled in poor countries.
Kathmandu, Nepal has been classified as a high‐risk area for highly pathogenic avian influenza (HPAI) by the Nepali Government. While ducks have an important role in the transmission of avian ...influenza viruses (AIV), including HPAI, seroprevalence of antibodies to AIV in domestic ducks of Kathmandu has never been assessed. The objectives of this study were (i) to estimate the prevalence of seroconversion to AIV in domestic ducks in major duck‐raising areas of Kathmandu and (ii) to assess the effect of age, sex, presence of swine and the number of ducks on the farm on the carriage of antibodies to AIV in these ducks. From April through July of 2011, a cross‐sectional study was conducted and a total of 310 ducks in the major duck‐raising areas of Kathmandu were sampled. The estimated prevalence of AIV antibodies was 27.2% 95% confidence interval (CI): 24.6–29.5. Of 62 enrolled farms, 42% had at least one seropositive duck. Half of the enrolled farms also kept pigs of which 52% had at least one seropositive duck. Bivariate analysis indicated association between ducks' seroconversion to AIV and their age, sex and farm size. However, the final multivariable model, after controlling for clustering of ducks within farms, identified age as the only significant risk factor. Based on this model, ducks older than 1 year of age were more likely to be seropositive compared to ducks <6 months of age odds ratio = 2.17 (1.07–4.39). These results provide baseline information about the AIV seroprevalence in domestic ducks in the major duck‐raising areas of Kathmandu and identify a high‐risk group that can be targeted in surveillance activities. Future studies should be conducted to differentiate the subtypes of AIV present among domestic ducks in Kathmandu, with particular interest in the presence of HPAI viruses.
Aims We analyse here the variations in species composition and richness and the geographic ranges of the tree species occurring in South American subtropical Atlantic and Pampean forests. Our goals ...were to assess (i) the floristic consistency of usual classifications based on vegetation physiognomy, climate and elevation; (ii) the leading role of temperature-related variables on the variations in species composition and richness; (iii) the predominance of species with tropical-subtropical ranges, possibly as a result of forest expansion over grasslands after the Last Glacial Maximum (LGM); (iv) the restriction of most subtropical endemics to stressful habitats as a possible result of past forest refuges during the LGM. Methods The region was defined by the Tropic of Capricorn to the north, the Rio de la Plata to the south, the Atlantic shoreline to the east and the catchment areas of the upper Paraná and Uruguay Rivers to the west. Multivariate analyses, multiple regression modelling and variance partition analyses were performed on a database containing 63 994 occurrence records of 1555 tree species in 491 forest sites and 48 environmental variables. All species were also classified according to their known geographic range. Important Findings A main differentiation in species composition and richness was observed between the eastern windward coastlands (rain and cloud forests) and western leeward hinterlands (Araucaria and semi-deciduous forests). Pre-defined forest types on both sides were consistent with variations in tree species composition, which were significantly related to both environmental variables and spatial proximity, with extremes of low temperature playing a chief role. Tree species richness declined substantially towards the south and also from rain to seasonal forests and towards the highland summits and sandy shores. Species richness was significantly correlated with both minimum temperature and actual evapotranspiration. About 91% of the subtropical flora is shared with the much richer tropical flora, probably extracting species that can cope with frost outbreaks. The 145 subtropical endemics were not concentrated in harsher habitats.
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