Vaccination of pigs with the S48 strain of Toxoplasma gondii – safer meat for human consumption

As clinical toxoplasmosis is not considered a problem in pigs, the main reason to implement a control strategy against Toxoplasma gondii (T. gondii) in this species is to reduce the establishment of T. gondii tissue cysts in pork, consequently reducing the risk of the parasite entering the human food chain. Consumption of T. gondii tissue cysts from raw or undercooked meat is one of the main sources of human infection, with infected pork being considered a high risk. This study incorporates a mouse bioassay with molecular detection of T. gondii DNA to study the effectiveness of vaccination (incomplete S48 strain) in its ability to reduce tissue cyst burden in pigs, following oocyst (M4 strain) challenge. Results from the mouse bioassay show that 100% of mice which had received porcine tissues from vaccinated and challenged pigs survived compared with 51.1% of mice which received tissues from non-vaccinated and challenged pigs. The presence (or absence) of T. gondii DNA from individual mouse brains also confirmed these results. This indicates a reduction in viable T. gondii tissue cysts within tissues from pigs which have been previously vaccinated with the S48 strain. In addition, the study demonstrated that the main predilection sites for the parasite were found to be brain and highly vascular muscles (such as tongue, diaphragm, heart and masseter) of pigs, while meat cuts used as human food such as chop, loin, left tricep and left semitendinosus, had a lower burden of T. gondii tissue cysts. These promising results highlight the potential of S48 strain tachyzoites for reducing the number of T. gondii tissues cysts in pork and thus improving food safety.     

Cacao,copoazu and macambo: Exploring Theobroma diversity in smallholder agroforestry systems of the Peruvian Amazon

Over the past decades, the general trend towards shade reduction and intensification of cacao management has led to biodiversity losses. In the Peruvian Amazon, the regional government is heavily promoting crop conversion to shift from regionally marketed foods towards cacao (Theobroma cacao) and copoazu (Theobroma grandiflorum). While this shift is already visibly impacting the farming landscape and the lives of many smallholder farmers, little is known about the reasons that drive farmers to choose certain types of Theobroma species or cacao varieties over others. In this paper, we addressed how cacao farmers perceive and manage specific and varietal Theobroma diversity. We interviewed cacao farmers (n?=?20) during a seed-exchange fair and adapted a version of the four-square analysis to explore which Theobromas are currently adopted by farmers and why. The native cacao variety (cacao chuncho) was the one cultivated by most farmers, followed by the more industrial clonal varieties. The source of seeds and seedlings for the most cultivated varieties was a mix of donations by public institutions (for clonal varieties) and informal exchange among farmers (mainly for native and criollo varieties, and species i.e. macambo (Theobroma bicolor) and cacauillo (Theobroma speciosum)). The cacao varieties incentivized by public institutions were the least desired for future investment. The motivations for farmers to plant Theobromas was mainly based on the perceived current and potential market, but their desire to invest in a given species or variety was also based on pest resistance, traditional use, farm diversification and taste. Copoazu and CCN cacao varieties are produced by many households in large areas, while macambo, cacauillo and the cacao varieties TSH and porcelana are produced by few households in small areas. Our study suggests that agroforestry systems that include alternative Theobroma species are multi-strata and more diverse than cacao-based systems. It highlights the risks of agrobiodiversity loss associated with the promotion of industrial cacao varieties, and the importance of seed and seedling access for the development of diverse farming systems. We recommend the expansion of local seed-sharing networks and the extension of public cacao-donation campaigns to neglected and underutilized Theobromas with socio-economic and environmental benefits, in order to make the local farming systems more diverse and resilient.

     

Correction to: Agroforestry can enhance foraging and nesting resources for pollinators with focus on solitary bees at the landscape scale

Agroforestry Systems - A correction to this paper has been published: https://doi.org/10.1007/s10457-021-00641-7     

Seropositivity and risk factors for Brucella in dairy cows in urban and peri-urban small-scale farming in Tajikistan

In this cross-sectional study, we assessed and mapped the seroprevalence of brucellosis in small-scale dairy farming in an urban and peri-urban area of Tajikistan and investigated factors associated with seropositivity. As urban and peri-urban farming is both an opportunity to improve the livelihood for small-scale farmers and a potential public health hazard, studies are warranted to reveal possible peculiarities in the epidemiology of brucellosis in this type of dairy farming. In total, 904 cows of breeding age belonging to 443 herds in 32 villages were serologically tested with indirect enzyme-linked immunosorbent assay (ELISA) and positive samples confirmed with competitive ELISA. Two logistic regression models were used to investigate an association between seropositivity and risk factors at herd and individual level. The herd and individual seroprevalences were 4.1 and 2.0 %, respectively. Herds with a history of abortions were found to be associated with seropositivity [odds ratio (OR)?=?5.3; 95 % confidence interval (CI), 1.3–21.3]. Large herds with more than eight cattle were more likely to be seropositive compared to smaller herds with one to two cattle (OR?=?13.9; 95 % CI, 1.6–119). The number of calves produced per cow (indicating age) was found to be associated with seropositivity. Younger cows with one to two produced calves were less likely to be seropositive compared to older cows with more than six produced calves (OR?=?0.24; 95 % CI, 0.06–1.0). Neither introduction of new cattle to the herd nor communal grazing was associated with seropositivity. This study shows that infection with Brucella (1) is present in small-scale urban and peri-urban dairy farming in Tajikistan and (2) has significant negative effects on reproductive performance in this farming system and (3) that some previously known risk factors for seropositivity in rural farming system were absent here.     

The establishment and impact of Pseudorasbora parva,an exotic fish species introduced into Lake Mikri Prespa (north-western Greece)

• 1. The topmouth gudgeon Pseudorasbora parva Schlegel, 1842, a south-east asian cyprinid, was introduced accidentally in the Danube Delta in Romania in the 1960s and has now achieved a pan-Danubian distribution. P. parva has been introduced into other countries, such as Greece, usually inadvertently included with other species imported for fish farming. In 1984–85, during a study of the fish populations of Lake Mikri Prespa (north-west Greece), several topmouth gudgeon were caught. Our aim was to study the changes in the population size of P. parva over nearly 10 years, to study its life history traits and to assess its potential impacts on native fish species.
• 2. The catch per unit effort (CPUE) in spring increased significantly between 1984 and 1992. We found evidence that P. parva has established a breeding population in the lake. P. parva combines many characteristics likely to favour a successful colonization (resistance to harsh climatic conditions, early sexual maturity, extended breeding season, broad dietary spectrum). Growth in Lake Prespa, where the oldest individuals captured were 3 years old, is very similar to that observed within its native range.
• 3. There is evidence for dietary overlap between P. parva and three endemic species: Paraphoxinus epiroticus prespensis, Cobitis meridionalis and Alburnoides bipunctatus ohridanus. No decline in the populations of these three species has yet been demonstrated. Other possible impacts are discussed. The successful colonization by P. parva was certainly favoured by the absence of a true piscivorous fish in the lake and by the isolation and high level of endemism of fish communities.
• 4. The conservation of the many endemic species in the lake should be a priority and the introduction of exotic species should be banned.

     

Branchial structure and hydromineral equilibrium in juvenile turbot (S<Emphasis Type="Italic">cophthalmus maximus)</Emphasis> exposed to heavy fuel oil

This study is an attempt to go further in the comprehension of the effects of heavy fuel oil in the context of an accidental oil spill at sea. It focuses on the link between morphological and functional impacts of realistic doses of the dissolved fraction of a heavy fuel oil on fish gills. Juvenile turbot, Scophthalmus maximus were exposed to the dissolved fraction of a heavy fuel oil for 5 days and then placed 30 days in clean sea water for recovery. During the contamination period, the concentration of the 16 US EPA priority poly-aromatic hydrocarbons showed small variations around a mean value of 321.0 ± 9.1 ng l⁻¹ (mean ± SEM). The contamination induced a 64% increase in hepatic cytochrome P 450 1A (Western blot analysis). Osmolality, [Na⁺] and [Cl⁻] rapidly and significantly increased (by 14, 23 and 28% respectively) and slowly decreased to normal levels during the recovery period. At the same time, branchial histology showed decreases in the number of mucocytes (by 30%) and of chloride cells (by 95%) in the interlamellar epithelium. Therefore, it is suggested that the osmotic imbalance observed after the 5 days of exposure to the dissolved fraction of the heavy fuel oil is the consequence of the structural alteration of the gills i.e, the strong reduction of ionocyte numbers.     

Fatty acid composition of 12 microalgae for possible use in aquaculture feed

Twelve algal strains representing the classes Cyanophyceae, Prymnesiophyceae, Bacillariophyceae, Rhodophyceae, Cryptophyceae, Chlorophyceae, Xantophyceae and Eustigmatophyceae were selected mainly from the culture collection of the Norwegian Institute for Water Research (NIVA). The algae were grown as continuous cultures in a 1.8 l. reactor, internally illuminated with an 11 W fluorescent tube. The retention time was adjusted in the range 2–4 days to fit the growth rate of the algae. The growth responses and fatty acid composition were analysed. The maximum production rate was obtained with Pseudokirchneriella subcapitata (0.63 g 1⁻¹ day⁻¹) and the lowest with Porphyridium cruentum 0.13 g 1⁻¹ day⁻¹. Arachidonic acid (AA) and eicosapentaenoic acid (EPA) were the dominating polyunsaturated fatty acids (PUFAs) in P. cruentum, while only EPA accumulated in Phaeodactylum tricornutum. Docosahexaenoic acid (DHA) was the major PUFA in Isochrysis galbana, while Pavlova sp. had both EPA and DHA. This is the first report on the fatty acid profiles of Nannochloropsis oceanica, Chroococcus sp., Synechococcus sp. and Tribonema sp.     

Comparative forcing of Hydrangea macrophylla ‘Bailer’ as a florist's hydrangea

‘Bailer’ (Endless Summer™) is a new, pink- or blue-flowered hydrangea that flowers on new wood continuously throughout the growing season. It is also winter-hardy in northern, temperate climates (USDA Z4). Use of Endless Summer as a florist's potted hydrangea would provide consumers with a dual-use product (flowering potted plant, landscape shrub). The objectives were to determine if Endless Summer could be forced as a florist's hydrangea using two forcing regimes (immediate, standard), two soil pH regimes, and two pinching treatments. ‘Merritt Supreme Pink’ (pink), ‘Blue Danube’ (blue), and Endless Summer (blue, pink) were forced under immediate (no cold treatment, short- and long-day photoperiods) and standard (6 weeks cold, 4 °C to overcome dormancy) conditions. Since commercial liners were not yet available, cuttings of Endless Summer were used in the immediate forcing experiment. Days to visible flower bud, first color, full flower were recorded, as well as height, no. of branches, no. of flowers, and flower size. In the immediate forcing experiment, only Endless Summer produced flowers. Cultivars differed significantly (P < 0.001) for days to visible flower bud, days to first color, days to full flower, and height. The number of flowers and flower size were not significantly different among pink cultivars. In the standard forcing experiment, Endless Summer reached days to visible flower bud, days to first color, and days to full flower significantly earlier than either comparison, although it exhibited weaker stems and less intense flower pigmentation. Pinching (blue pH) had a significant effect on all traits except the days to full flower and flower size, although no pinching treatment was significant for pink pH. Photoperiod was significant only for the days to visible flower bud (pink pH), days to full flower (blue pH), and final height (blue pH). Further research is needed before Endless Summer can be grown as a dual-use florist's potted hydrangea with acceptable quality.     

Behaviour of lignin during thermal treatments of wood

Different thermal treatments or processes (combustion, welding, thermowood) of several wood species were examined and compared. Each procedure resulted in different temperature loads on wood. The changes of lignin after thermal treatments were determined by different suitable methods, both wet chemical and instrumental analyses.The characterisation of the wood meals by means of FTIR spectroscopy has shown that changes of the aromatic skeletal vibrations occur, which indicate condensation reactions of lignin. The variations within the FTIR spectra of hardwood were more evident than those of softwood.The decomposition of lignin has also been proven in the acetone extracts of “thermowood”, which contained a lignan, identified by GC/MS.Moreover, the thioacidolysis showed the decrease of monomeric degradation products in all thermal treated samples. This is due to the cleavage of structural units bound by arylgycerol-β-ether linkages.However, it can be assumed that in addition to the degradation of specified types of bonds also condensation reactions have occurred and these products were not detectable by means of GC/MS. This conclusion would also support the above-mentioned results of FTIR spectroscopy.