Dynamic use of coastal areas by bull sharks and the conciliation of conservation and management of negative human–wildlife interactions

1. Knowledge about spatial and temporal variability in the distribution and abundance of predators is necessary to adapt measures to mitigate human–wildlife interactions.
2. Acoustic telemetry and network analyses were used to investigate the spatial ecology of bull sharks, the species responsible for most shark bites in Reunion Island, one of the world's shark bite hotspots.
3. The west coast of the island was not used uniformly by every individual, with size predicting the movements of sharks along the coast.
4. Node-based metrics – closeness, node strength, and cumulated continuous residency times – derived from up to 181 monthly movement networks from 20 individuals, revealed that smaller sharks (<250 cm total length) primarily used the south-west coast while larger individuals spent most of their time in the northern region with regular visits to multiple areas along the coast.
5. This study provides essential knowledge on bull shark behaviour and central areas used at different periods of the year, which correlates well with the dynamics of observed shark bites. Our approach provides a non-invasive alternative to help predicting and anticipating human–shark conflicts and avoid shark culling programmes detrimental to the conservation of large predators such as sharks.

     

Use of a simplified HPLC-UV analysis for soyasaponin B determination: study of saponin and isoflavone variability in soybean cultivars and soy-based health food products

Soyasaponins are phytochemicals of major interest for health. Their identification and quantification remain difficult owing to the large number of structural isomers in soybeans and the lack of stable standards. In this study, a rapid method using high performance liquid chromatography (HPLC) using a UV detector (205 nm) was developed to identify and quantify soyasaponins belonging to group B and compare them with isoflavones in different soy materials. 2,3-Dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP)-conjugated soyasaponins were determined using external calibration or a molecular mass ratio after alkaline hydrolysis to cleave their DDMP moieties. The detection limit of soyasaponin I, used as a reference molecule to simplify the analysis, was 0.065 micromol/g. Soyasaponin contents in seven soybean varieties ranged from 13.20 to 42.40 micromol/g in the germ and from 2.76 to 6.43 micromol/g in the cotyledons. The within-day and between-days variation coefficients did not exceed 7.9 and 9.0%, respectively, for the major soyasaponins. Soyasaponin B quantification in different soy-based health supplements was reported along with measurements of their isoflavone content to provide information on the variability of these bioactive compounds among different types of soy food materials.     

Effect of azadirachtin-derived decalin (perhydronaphthalene) and dihydrofuranacetal (furo[2, 3-fo]pyran) fragments on the feeding behaviour of Spodoptera littoralis

Decalin and dihydrofuranacetal fragments related to those in azadirachtin exhibited antifeedant activity against larvae of the African leaf-worm Spodoptera littoralis. Boisd. All the decalin fragments tested were methoxy (C11) derivatives of azadirachtin. The most active decalin fragment had a ketone substitution at C7. Overall, the compounds were more active when tested in combinations of one decalin fragment and one dihydrofuranacetal fragment than when tested singly. Although some of these combinations did show significant levels of antifeedant activity, sometimes coupled with a synergistic effect, they were not as active as either azadirachtin or dihydroazadirachtin.     

Tissue-culture propagation of banana

The possibility of clonal propagation of banana through tissue culture was explored. Shoot tips isolated from the rhizomes were found to be suitable material for plantlet production in vitro. Excised shoot tips with the youngest leaves produced only one plantlet. However, shoot tips with several older sheathing leaf bases enclosing the axilary buds regenerated multiple plantlets. Individual shootlets, when separated and sub-cultured, produced a new crop of multiple shoots. The plantlets obtained from both types of explants have been successfully transplanted to soil and grown to maturity.     

The ECVP/ESVP summer school in veterinary pathology: high-standard, structured training for young veterinary pathologists

This article describes the ECVP/ESVP Summer School in Veterinary Pathology, a new annual two-week European training facility established by the European College of Veterinary Pathologists (ECVP) in collaboration with the European Society of Veterinary Pathology (ESVP). The aim of the Summer Schools is to provide Europe-wide, harmonized, top-standard theoretical and practical post-graduate training for veterinarians specializing in veterinary pathology. In particular, it aims to support trainees in veterinary pathology in their individual preparation for the ECVP certifying examination. Ultimately, it aims to provide young pathologists with the skills and knowledge necessary to participate in international, high-quality research and the tools for applying international standards to their own research and for independent study for the ECVP certifying examination, even if they do not work in comparable academic environments and do not have the same level of local support and training. The ECVP/ESVP Summer Schools take place in European countries, with local organization from a university department of veterinary pathology. Each event comprises modules provided by internationally recognized specialists in their specific fields of expertise on different organ systems, diseases of specific species, specific techniques, and specific topics relevant to pathology, forming a cycle of four events to cover all major topics. Every two years a mock exam is organized as a tool to monitor individual progress in preparing for the ECVP certifying examination.     

Cerebral Accumulation of Dietary Derivable Plant Sterols does not Interfere with Memory and Anxiety Related Behavior in Abcg5?/? Mice

Plant sterols such as sitosterol and campesterol are frequently applied as functional food in the prevention of atherosclerosis. Recently, it became clear that plasma derived plant sterols accumulate in murine brains. We questioned whether plant sterols in the brain are associated with alterations in brain cholesterol homeostasis and subsequently with brain functions. ATP binding cassette (Abc)g5-/- mice, a phytosterolemia model, were compared to Abcg5+/+ mice for serum and brain plant sterol accumulation and behavioral and cognitive performance. Serum and brain plant sterol concentrations were respectively 35-70-fold and 5-12-fold increased in Abcg5-/- mice (P<0.001). Plant sterol accumulation resulted in decreased levels of desmosterol (P<0.01) and 24(S)-hydroxycholesterol (P<0.01) in the hippocampus, the brain region important for learning and memory functions, and increased lanosterol levels (P<0.01) in the cortex. However, Abcg5-/- and Abcg5+/+ displayed no differences in memory functions or in anxiety and mood related behavior. The swimming speed of the Abcg5-/- mice was slightly higher compared to Abcg5+/+ mice (P<0.001). In conclusion, plant sterols in the brains of Abcg5-/- mice did have consequences for brain cholesterol metabolism, but did not lead to an overt phenotype of memory or anxiety related behavior. Thus, our data provide no contra-indication for nutritional intake of plant sterol enriched nutrition.     

Within-site habitat configuration in reserve design: A case study with a peatland bird

This study assesses the effects of considering within-site habitat configuration when designing reserve networks. This attribute takes all its importance in situations where the long-term integrity of (within-site) habitat patches cannot be preserved without protecting their surrounding environment. We addressed this issue through the concrete problem of selecting a reserve network of natural peatlands in southern Québec, Canada. We used a reserve-selection algorithm that minimized the total number of peatlands to include within networks. The algorithm was constrained to include peatlands containing habitat patches that met specific size thresholds. Five habitat-clustering thresholds were used to set the eligibility of each site to the selection process. The resulting reserve networks were evaluated according to their representation efficiency and to the expected consequences for the Palm Warbler (Dendroica palmarum), an area and isolation-sensitive bird restricted to peatlands in southern Québec.Constraining the algorithm to include peatlands showing increasingly larger patches of habitats led to larger networks, both in terms of area and number of sites, and to networks composed of smaller sites. These effects increased with the representation target (i.e., the % of each habitat preserved). With respect to the Palm Warbler, selecting peatlands with larger patches of habitats had only an indirect effect on its site-occupancy pattern. Indeed, despite the fact that the probability of occurrence of the warbler was negatively correlated with the size of habitat patches, the habitat-clustering threshold influenced the incidence of the warbler mainly via its effect on the physical attributes of the selected networks - including the area, isolation level, and the number of selected sites. Because increasing the habitat-clustering threshold led indirectly to a greater regional availability of prime breeding habitats for the Palm Warbler, it mitigated the severe negative impact of an hypothetical alteration or destruction of non-selected peatlands. Our study thus emphasizes the importance of determining how the different factors describing within-site configuration are correlated with other intrinsic characteristics of the sites available to the selection process before opting for a site-selection strategy.