Recruitment and regeneration in populations of an endangered South Iberian Tertiary relict tree

The southern Iberian Peninsula is one of the most important refugia of Tertiary relict plant taxa in Europe. Under the present summer-dry climate, relict populations may experience a severely reduced regeneration. We studied the demographic structure, seed set and initial recruitment in relict populations of the endangered tree Frangula alnus subsp. baetica (Rhamnaceae) to evaluate its regeneration potential under the present environmental conditions. Populations are restricted to small riparian forests of Southwest Spanish and North Moroccan mountain ranges. The distribution of fruit crop sizes was highly left-skewed, and a few old trees produced the large bulk of the population seed pool. Bird-mediated seed dispersal appeared inefficient and post-dispersal seed predation by mice was high. Secondary seed transport by elevated creek water flow after winter rains modified the primary seed dispersal, but in consequence most seeds germinated on recently formed sandbanks where seedlings experienced reduced initial growth and survival. The most important mortality factor was desiccation, followed by herbivory. None of 1144 monitored seedlings survived for 2 years. The demographic survey through five populations indicates that drought periods may cause temporal regeneration bottlenecks. Moreover, over the last two decades populations have experienced increasing regeneration problems. Two causes are suggested: (1) browsing pressure from introduced game animals, and (2) the impact of torrential water flow peaks after heavy winter rains, exacerbated by large-scale vegetation slashing in surrounding cork oak forests. We discuss conservation strategies for this and other relict tree species that account for the pecularities of their habitat within the Mediterranean.     

Soybean vegetable protein (Tofu) preserved with high pressure

Tofu is a soybean vegetable protein that Asians have long consumed; its intake is increasing in other countries. Tofu was purchased at a local shop. The tofu samples were already preserved in plastic bags subjected to vacuum and storage (5 C). Tofu samples were subjected to high pressure (HP) of 400 MPa at 5 C for 5, 30, and 45 mm. Microbial analysis, sensorial evaluation, and structure were determined. HP treatment in tofu reduces the microbial population. Most of the microorganisms found in the initial population belonged to the Enterobacteriaceae family, bacteria Gram-negative (no Enterobacteriaceae), and bacteria Gram-positive. Alter HP treatment, Hafnia alvei and Bacillus cereus were found. After HP treatment, tofu is a pasteurized product, which is safer in terms of secondary pathogenic microbial contamination. Sensorial test results revealed that treated tofu was acceptable to consumers. The micrographs on the cryofracture observed with a cryoscanning electron microscope revealed a more compact structure after pressure compared with that of untreated samples, but the aggregates in the treated samples were more disperse.     

Kinetic study of the physicochemical and microbiological changes in "seasoned" olives during the shelf-life period

The changes that take place during the shelf life of "seasoned" olives (packing conditions: 4% NaCl, 0.1%citric acid, and 0.0175% sorbate) using fresh (FF) and stored (SF) cracked fruits were studied. Texture, L, b, NaCl, and pH experienced slight changes. Values of a and titratable and combined acidity increased following a first-order kinetic with higher constants for FF. Glucose was completely exhausted, and mannitol showed only a slight decline. Hydroxytyrosol and tyrosol contents in brines increased rapidly from the acidic hydrolysis of oleuropein, hydroxytyrosol-4-beta -d-glucoside, and salidroside, the concentrations of which decreased. Sorbate content decreased with time and disappeared completely in SF. Yeasts grew rapidly in FF and were markedly inhibited in SF. There was a moderate growth of lactic acid bacteria in FF, whereas they grew markedly in SF during the first few days. Some of these changes limit the shelf life of the product.     

Rainfall and breed effects on the efficacy of ivermectin jetting fluid for the prevention of fly strike and treatment of infestations of lice in long-wooled sheep

SUMMARY An ivermectin-based jetting fluid was assessed for its efficacy in the prevention of blowfly strike and treatment of lice in long-wooled sheep. The ivermectin concentrate was diluted to 0.03 mg/mL and applied via a standard hand jetting technique. In insectary studies, using laboratory-reared Lucilia cuprina, sheep jetted with ivermectin were protected from induced breech and body strikes for 18 weeks after treatment. Merino and Corriedale sheep were equally protected, as were sheep subjected to 25 mm simulated rainfall at 1, 3 or 6 hours after jetting. Naturally occurring infestations of lice, Bovicola (Damalinia) ovis, were successfully treated with ivermectin jetting fluid in Merino and Corriedale sheep using a standard hand jetting technique. In addition, the efficacy of treatment was not affected by simulated rainfall at 1, 3 or 6 hours after treatment.     

Historical aspects of Potomac horse fever in Ontario (1924–2010)

In the summer of 1924 Dr. Frank W. Schofield conducted investigations into an endemic disease of horses in the Kent and Essex counties of Ontario. According to farmers in these counties the disease had existed in this region for at least 50 years previously. The clinical, pathological, histopathological, and epidemiological findings outlined in Schofield’s detailed report strongly suggest that this endemic disease was what was designated in 1979 as “Potomac horse fever” (PHF). This assumption is further substantiated by transmission experiments involving horses and laboratory animals that were conducted by Schofield utilizing horse feces, whole blood, and mayflies. The aim of this paper is to present Schofield’s detailed investigations and findings and to compare these with PHF research conducted from 1979 to 2010 that ultimately led to the discovery of Neorickettsia risticii as the etiological agent and to elucidation of the organism’s complex life cycle.     

Using distribution models to test alternative hypotheses about a species’ environmental limits and recovery prospects

Distribution models are commonly used to generalise across species distributions, to project future potential range changes, and to identify potential areas for species reintroductions and recovery plans. Building several models that incorporate different potential causal factors is a useful way of formalising alternative hypotheses. We developed a series of models to test hypotheses about the factors influencing the distribution of a species of conservation importance - the hen harrier Circus cyaneus.A climate-based model using continental distribution data was consistent with the continental distribution and observational studies in Britain. According to the climate-model the parts of Britain occupied by the hen harrier are the least climatically suitable.Habitat-based models using detailed distribution data from seven Scottish areas explained the recent British distribution well, with birds largely confined to heather dominated areas. These patterns were inconsistent with historical data on the species’ distribution, its habitat use in other parts of its range and with the climate-based model.Our burn intensity index of gamekeeper activity was highly correlated with climatic suitability within the best 25% of 10 km squares by modelled habitat suitability, negatively associated with the productivity data and associated with a decrease in abundances between 1998 and 2004. Gamekeeper activity may be keeping hen harriers out of the most climatically suitable areas with habitat similar to that which they currently occupy within Britain and or keeping the population numbers too low and isolated for the natural re-expansion of the species into parts of the range where it was historically extirpated.     

Effects of dietary protein level during rearing period and age at overfeeding on magret and foie gras quality in male mule ducks

The aim of this trial was to study the effects of dietary protein content during the rearing period on the performance of mule ducks, according to age at overfeeding (O). Ducks (n = 612) were divided into four groups differing in the protein content in the diet offered during the starting period (S, 0–20 days; S_l vs. S_h: 150 vs. 175 g/kg crude protein (CP)) and growing‐finishing period (GF; 21–67 or 81 days, depending on age at O; GF_l vs. GF_h: 133 vs. 152 g/kg CP). The relative weight of pectoral muscle was lower when ducks were fed a low protein diet during S (?5%, P < 0.01) or GF period (?6%, P < 0.001) at 68 days and higher in ducks of the S_lGF_h group (+6%; P < 0.05) at 82 days. Both foie gras and magret weights fell when ducks were fed S_l or GF_l (P < 0.05 and < 0.01). Mortality during the O period was higher in ducks fed the S_l diet and overfed at late age (7.4% vs. 0%; P < 0.01). In conclusion, a reduction in the dietary protein supply should be recommended only during the GF period for ducks overfed at a late age.     

Arterial calcification in race horses

Calcification of large arteries has been sporadically reported in horses. The pathogenesis is still unknown, but recent studies in humans suggest that this is a regulated biomineralizing process. This study surveyed the prevalence, distribution, and severity of vascular calcification in Thoroughbred and Standardbred racehorses. Histopathologic, ultrastructural imaging, and energy dispersive X-ray elemental analyses were used to examine the lesions. Calcification of the tunica media, predominantly the pulmonary artery, was found in 82% of horses (83/101). Young adult horses (mean [SD] age in years, 4.44 +/- 2.17) of both breeds and sexes were similarly affected. Lesions appeared as white-to-yellowish, hard, and gritty plaques of variable size. On microscopic examination, elastic fibers within the tunica media were thinned, fragmented, and calcified, and surrounded by dense collagen matrix. Elemental analysis showed distinct peaks for calcium and phosphorus, consistent with hydroxyapatite mineral. The frequent occurrence of calcification in the tunica media of large pulmonary arteries of young racing horses indicates the need to investigate its pathogenesis and potential clinical implications.