Use of state‐space modelling to identify ecological covariates associated with trends in pinniped demography

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Evaluating the use of garlic (Allium sativum) for the remedy of Cryptocaryon irritans in guppies (Poecilia reticulata)

Garlic (Allium sativum) has been shown to possess antimicrobial properties against a range of disease‐causing agents, including fish parasites. Our study aimed to investigate the potential use of garlic as a treatment against Cryptocaryon irritans infection, using guppies (Poecilia reticulata) as the fish model. Garlic was freeze‐dried, powdered, and used as it is or as an aqueous extract. The content of allicin, its main active ingredient, was 1.25 mg/g in garlic powder and 0.82 mg/ml in the aqueous extract, as determined by HPLC analysis. Aqueous garlic extract fully immobilized C. irritans theronts and protomonts within 20 and 40 min, respectively, following exposure to 5 µl/ml. Treatment trials were performed, in which infected fish were fed with garlic powder‐supplemented feeds (5%, 10%, or 20% supplementation), bathed in garlic aqueous extract (250 or 500 µl/L) and subjected to a combined treatment which included both feeding and bathing. Results revealed that the tested treatments failed to cure the infection, though reduction in infection intensity on the caudal fin, but not on the gills, was evident following dietary supplementation with 20% of powdered garlic in one of the trials.     

Understory vegetation of boreal tree plantations: Differences in relation to previous land use and natural forests

The aim of this study was to evaluate if and how the previous land use (here: agriculture versus forest) has influenced the floristic composition now observed in the understory of jack pine plantations of Abitibi-Temiscamingue (North-Eastern Canada). Floristic inventories were conducted in jack pine plantations which had been established on forest sites after logging and on sites previously utilized for agriculture. These were compared to one another and to inventories conducted in natural forests and on agricultural sites which had not (not yet) been planted with trees (old fields). The vegetation community composition of the sites is analysed using several multivariate techniques. Results show that the flora of plantations on old agricultural fields is markedly different than that of plantations established on sites which were previously forested and that the two types of plantation are unlikely to become floristically the same before the anticipated harvest time. Comparing old and young plantations and old fields in light of natural forests sites, we show that the previous land-use is a key determinant of future compositional differences in plantations. This must be considered when we evaluate the impact of establishing plantations on sites with different land-use histories.     

The impact of body site, topical melatonin and brushing on hair regrowth after clipping normal Siberian Husky dogs

The aims of this study were to determine the impact of body site, vigorous brushing and topical melatonin treatment on hair regrowth after clipping normal dogs. Siberian Husky dogs were randomly assigned to three groups of eight dogs each. All dogs had the lumbosacral region and both lateral thighs clipped. The left thigh and lumbosacral area received no treatment and were compared in all 24 dogs. Eight dogs had the right thigh treated with 0.1% melatonin twice daily for 2 months, and hair regrowth was compared with the left thigh. Eight dogs had the right thigh brushed twice daily for 2 months, and hair regrowth was compared with the left thigh. Eight dogs had neither thigh treated. Hairs were plucked before and 2 months postclipping, and the proportion of hair growth from the original length was calculated and compared as described above. Biopsy samples were collected before and after treatment to determine if brushing induced dermal inflammation and melatonin increased the proportion of anagen follicles. Proportionally, left thigh hairs were significantly longer compared to lumbosacral hairs 2 months postclipping. No significant differences in hair regrowth were noted between the nontreated thigh and the thigh treated with melatonin or brushed. No significant difference in dermal inflammation was noted before and after brushing. No significant differences were observed in the proportion of anagen follicles before and after topical melatonin treatment. Our results showed that the hairs in the lumbosacral region were proportionally shorter than lateral thigh hairs 2 months postclipping. Moreover, topical melatonin and brushing had no impact on hair regrowth after clipping normal dogs.     

Changes in wind pattern alter albatross distribution and life-history traits

Westerly winds in the Southern Ocean have increased in intensity and moved poleward. Using long-term demographic and foraging records, we show that foraging range in wandering albatrosses has shifted poleward in conjunction with these changes in wind pattern, while their rates of travel and flight speeds have increased. Consequently, the duration of foraging trips has decreased, breeding success has improved, and birds have increased in mass by more than 1 kilogram. These positive consequences of climate change may be temporary if patterns of wind in the southern westerlies follow predicted climate change scenarios. This study stresses the importance of foraging performance as the key link between environmental changes and population processes.     

Botulinum neurotoxin is shielded by NTNHA in an interlocked complex

Botulinum neurotoxins (BoNTs) are highly poisonous substances that are also effective medicines. Accidental BoNT poisoning often occurs through ingestion of Clostridium botulinum-contaminated food. Here, we present the crystal structure of a BoNT in complex with a clostridial nontoxic nonhemagglutinin (NTNHA) protein at 2.7 angstroms. Biochemical and functional studies show that NTNHA provides large and multivalent binding interfaces to protect BoNT from gastrointestinal degradation. Moreover, the structure highlights key residues in BoNT that regulate complex assembly in a pH-dependent manner. Collectively, our findings define the molecular mechanisms by which NTNHA shields BoNT in the hostile gastrointestinal environment and releases it upon entry into the circulation. These results will assist in the design of small molecules for inhibiting oral BoNT intoxication and of delivery vehicles for oral administration of biologics.