Encapsulation of Salmon Peptides in Marine Liposomes: Physico-Chemical Properties,Antiradical Activities and Biocompatibility Assays

Salmon byproducts (Salmo salar) generated by the food chain represent a source of long-chain polyunsaturated fatty acids (eicosapentaenoic acid (EPA): 20:5n-3; docosahexaenoic acid (DHA): 22:6n-3) and peptides that can be used as supplements in food for nutraceutical or health applications, such as in the prevention of certain pathologies (e.g., Alzheimer’s and cardiovascular diseases). The extraction of polar lipids naturally rich in PUFAs by enzymatic processes without organic solvent (controlled by pH-Stat method), coupled with the production of 1 kDa salmon peptides by membrane filtration, allowed the formulation of nanocarriers. The physicochemical properties of the nanoliposomes (size ranging from 120 to 140 nm, PDI of 0.27, zeta potential between −32 and −46 mV and encapsulation efficiency) were measured, and the bioactivity of salmon hydrolysate peptides was assessed (antioxidant and antiradical activity: ABTS, ORAC, DPPH; iron metal chelation). Salmon peptides exhibited good angiotensin-conversion-enzyme (ACE) inhibition activity, with an IC₅₀ value of 413.43 ± 13.12 µg/mL. Cytotoxicity, metabolic activity and proliferation experiments demonstrated the harmlessness of the nanostructures in these experimental conditions.     

A methodology for assessing the risk posed by the deliberate and harmful use of plant pathogens in Europe

Deliberate and malevolent use of plant pathogens, i.e. agroterrorism lato sensu (anticrop bioterrorism and use of bioweapons against the agricultural sector), may represent a non-negligible threat for crops and forests in Europe. In order to assess this risk objectively, a methodology based on a critical review of existing Pest Risk Analysis schemes has been elaborated and is described in the present paper. In this methodology, three interdependent steps are suggested: (i) definition of an a priori list of potentially dangerous plant pathogens for Europe, (ii) detailed elaboration and analysis of theoretical scenarios of possible acts of agroterrorism, and (iii) elaboration and use of a risk assessment scheme adapted to agroterrorism.     

Open woodland and savanna decline in a mixed-disturbance landscape (1938 to 1998) in the Northwest Wisconsin (USA) Sand Plain

Our research illustrates how a landscape mosaic changes in association with a mixed natural-anthropogenic disturbance history. Our study area is the Northwest Wisconsin (USA) Sand Plain (NWSP), a region with a rich disturbance history including fire, insects and clearcut forestry. We integrated historic airphotos from 1938, 1960, 1980 and 1998 within a GIS to describe change among four landcover classes describing a canopy-closure gradient: closed forests, woodlands, savannas and “open barrens”. Our work addresses two literature needs: empirical studies of mixed-disturbance landscapes, and nonforest habitats within a forest matrix. Our analysis shows that: the area of open barrens fluctuated, woodlands and savannas declined severely and closed forests increased through time. Falling median patch sizes and other landscape metrics suggest that the woodlands are becoming more fragmented. The landcover transitions driving this change vary according to time and place. The dominant transitions are toward closed forests from all classes, and transitions toward open barrens are also consistently important. The woodlands, savannas and open barrens habitats are mostly comprised of transient patches, persisting for less than 20 years. This contrasts with closed forests that often persist for 40 plus years. These changes are consistent with the disturbance regime that is shifting from fire- to forestry-dominance. Our results show a trend towards landscape simplification, manifest as losses of intermediate-density habitats (woodland and savanna) and shrinking patch sizes. The transient nature of the nonforest habitats shows that disturbance resulting in total or partial canopy removal will be vital for their conservation at a landscape scale.     

Neospora caninum seroprevalence and associated risk factors in beef cattle in the northwestern United States

A Neospora caninum seroprevalence and risk factor survey of 2585 cows was conducted in 55 beef cow-calf herds located in five northwestern states of the USA. Blood samples were collected by private veterinary practitioners and management practices were surveyed using a mail questionnaire. Producers were randomly selected from those that employed these veterinarians to perform annual herd pregnancy examinations. Questions were asked about animal management, grazing and feeding, immunization and record keeping practices. Blood was collected from a systematically selected sample of cows in each herd, and age, origin, and pregnancy status were recorded. Blood samples were analyzed for antibodies against N. caninum antigen using a monoclonal antibody-based competitive inhibition (CI) ELISA. Overall seroprevalence was 24% and within herd seroprevalence ranged from 3 to 67% with a median of 19%. Within herd seroprevalence and mean inhibition percentage were different between the five states. Herds that managed their cows on range for summer grazing had lower seroprevalence than those that did not, while increased seroprevalence was associated with higher winter stocking density. Cows less than 3 years of age had higher CI ELISA inhibition percent values than cows greater than 6 years of age. No relationship was noted between serologic status and individual cow origin (purchased or raised), or pregnancy status at the time of sampling.     

Comparative medicine

Many scientists are conducting research on human diseases which cannot be transmitted readily to laboratory animals or duplicated in the laboratory. Information offered by animal disease models should be compiled and made available to these scientists through the publication of extensive lists of animal disease models and annotated bibliographies for specific conditions.     

Experimental evolution of reduced sex ratio adjustment under local mate competition

Theory predicts that local mate competition (LMC) favors the evolution of female-biased sex ratios. Empirical support of this prediction is indirect and comes from comparative studies or from studies showing that individuals can adjust their offspring sex ratio in response to varying LMC intensities. Replicate lines from a population of the spider mite Tetranychus urticae were selected under three LMC intensities for up to 54 generations. Within each selection regime, the final sex ratio matched theoretical predictions. Furthermore, the ability of individuals to adjust their offspring sex ratio diminished in females evolving under strict LMC, but not in females evolving under relaxed LMC levels. These results provide direct experimental evidence for the evolutionary process by which LMC modifies sex-allocation strategies and suggest that evolution under strict and constant LMC may lead to a loss of phenotypic plasticity.     

Interfacial polygonal nanopatterning of stable microbubbles

Micrometer-sized bubbles are unstable and therefore difficult to make and store for substantial lengths of time. Short-term stabilization is achieved by the addition of amphiphilic molecules, which reduce the driving force for dissolution. When these molecules crystallize on the air/liquid interface, the lifetime of individual bubbles may extend over a few months. We demonstrated low gas-fraction dispersions with mean bubble radii of less than 1 micrometer and stability lasting more than a year. An insoluble, self-assembled surfactant layer covers the surface of the microbubbles, which can result in nanometer-scale hexagonal patterning that we explain with thermodynamic and molecular models. The elastic response of the interface arrests the shrinkage of the bubbles. Our study identifies a route to fabricate highly stable dispersions of microbubbles.     

Primary extracranial nasopharyngeal meningioma in a dog

An 8‐year‐old Labrador Retriever was presented for inspiratory efforts with stertor. A rhinoscopy and a magnetic resonance imaging scan were performed and revealed a naso‐pharyngeal mass. The mass was identified in the nasopharynx without meningeal extension. This mass was both T1‐ and T2‐hyperintense, compared to normal brain parenchyma without significant postcontrast enhancement. The mass was surgically removed and the histologic diagnosis was a mesenchymal tumor. Immunohistochemistry with antibodies was conducted and consistent with an extracranial meningioma. To the authors’ knowledge, this is the first case report documenting a primary extracranial nasopharyngeal meningioma in a dog.