Novel dry forests in southwestern Puerto Rico

We report results of new research on (1) community composition of novel subtropical dry forests developing on abandoned pastures and agricultural fields in both private and protected public lands and (2) seed germination and growth rates of plantings of native tree species on degraded soils. We found that novel dry forests were dominated by introduced species, which accounted for 59 percent of the Importance Value (IV) of stands. These forests had high species dominance, with the most dominant species averaging 51 percent of the IV but reaching values as high as 92 percent. The floristic similarity between novel and mature native forests was low (5.6 percent) compared with the similarity among novel forest stands (26 percent). Collectively, the emerging novel forests had relatively high species richness (39 species/1.2 ha). After 45-60 years of growth and development, novel forests lagged mature native forests in basal area, tree density, and species richness, and lagged stands of similar age and past land use inside a protected area. Novel forest stands inside the protected Guánica Forest had higher species richness than those located outside in private lands. Most regeneration was from seed (67 percent of the new stems were single stems). The results from the germination and planting experiment show that seeds of 17 of 21 native tree species germinated in the laboratory and grew successfully in abandoned pastures when planted and watered for a period of 13 months. Our research shows that after the initial invasion and dominance of introduced species on degraded sites, the stands diversify with native species thus evolving towards new forest types with novel species combinations.     

Decline of maternal antibodies to small ruminant lentivirus in goat kids

We carried out this study to determine for how long small ruminant lentivirus (SRLV)‐specific antibodies can be detected by three commercial ELISA kits in goat kids after suckling infected does in field conditions. Forty‐one kids born to SRLV‐seropositive asymptomatic does were blood sampled prior to colostrum consumption, and then weekly for 6 months in total. The sera were screened with three commercial ELISA kits: whole‐virus ELISA (wELISA), recombinant transmembrane and capsid antigen ELISA (TM/CA‐ELISA), and surface antigen ELISA (SU‐ELISA). All but one kid were seronegative in all three ELISAs right after birth. At the age of 1 week all kids turned seropositive in wELISA, 39 kids (95%) in TM/CA‐ELISA, and 35 kids (85%) in SU‐ELISA. All seropositive kids turned seronegative in wELISA by the 15th week, and in SU‐ELISA by the 19th week (median of 8 weeks in both ELISA), whereas in TM/CA‐ELISA five kids (13% of 39 initially seropositive) were still seropositive at the age of 6 months (median of 11 weeks). Antibody levels at the age of 1 week proved significantly linked to the duration of maternal antibodies in all three ELISAs and could be employed to predict for how long maternal antibodies would remain detectable.     

Current knowledge and new assumptions on the evolutionary history of the African lungfish,Protopterus, based on a review of its fossil record

Lungfish have a large fossil record that started over 400 Ma ago and a relict modern diversity within Australia, Africa and South America. Their study mostly concentrates on their sister‐group relationship with the tetrapod vertebrates, on their early evolution and on the physiology of their air breathing and of the ability of certain species to aestivate. Conversely, little is known about the evolutionary history of modern taxa. In this study, the focus is on the single polytypic extant genus, Protopterus. Four species and seven subspecies are currently present in African freshwater. As fossils, Protopterus are recognized by their heavy tooth plates. Indeed, the review of the diagnostical characters shows that so far we are not able to confidently distinguish fossil species. The fossil record is thus explored through the analysis of the distribution of the genus. A comprehensive scenario for their evolutionary history is built by including also knowledge of the ecology, distribution and phylogeny of modern Protopterus, in the context of the environmental changes that affected Africa over the last 100 Ma. The genus has been present in Africa for at least 100 Ma when the continent separated from South America. Northern Africa might be the cradle for the African lineage, but other regions of Africa cannot be ruled out. During the Paleogene, lungfish disappeared from northern Africa, whereas modern Protopterus arose in a peri‐equatorial area with dispersal from this area late in the Pliocene. This correlates with great environmental change that occured during the last 25 Ma in eastern Africa.     

Cross-sectional study of Brucella spp. using real-time PCR from bovine whole blood in Colombia

Veterinary Research Communications - A cross-sectional study was conducted in Colombia to recover Brucella spp. DNA from bovine whole-blood samples through probe-based real-time PCR (qPCR). By an...     

Decision support system for forest fire protection in the Euro-Mediterranean region

This paper describes the development of a decision support system (DSS) for prevention planning and emergency management of forest fire events that incorporates weather data management, a geographical data viewer, a priori danger forecasting and fire propagation modeling, automatic fire detection, and optimal resource dispatching. Collection, input, storage, management, and analysis of the information rely on advanced and automated methodologies using remote sensing, GPS, digital mapping, and geographic information systems. The results included short-term dynamic fire danger indices developed for improved and realistic prevention and pre-suppression planning. An automatic fire detection technology based on infrared video was developed and successfully tested on site. Several models for understanding fire propagation on forest fires have been proposed for practical application. Additionally, a DSS was developed with the innovation of covering wildland fire hazard management entirely, providing a complete coverage of technical and administrative activities that support decision makers in real time. The DSS was tested for high fire seasons in two different sites in South Europe.     

Influence of long term ammonia exposure on Atlantic salmon (Salmo salar L.) parr growth and welfare

The objective of this study was to determine the long‐term effects of ambient unionized ammonia nitrogen (NH₃‐N) combined with different feeding regimes on Atlantic salmon Salmo salar L parr growth, welfare and smoltification. Previous studies on the parr stage of Atlantic salmon have mostly focused on acute exposure, or at low temperatures. Atlantic salmon parr were exposed for 105 days (at 12°C, pH 6.8) to four sublethal ammonia concentrations ranging from 0.1 to 35 μg L^?1 NH₃‐N (0.1–25 mg L^?1 TAN) at two feeding levels: full feed strength (+20% overfeeding) and 1/3 of full feed strength. After 21 days, it was observed that 32 μg L^?1 NH₃‐N reduced growth rate of parr fed full ration, but this effect was not evident at the end of the exposure. Feed utilization was not affected by ammonia exposure at any sampling point. Increasing ammonia levels were associated with a higher prevalence and severity of gill damage at 22 days but not at the end of the exposure. The examination of welfare indicators revealed only a few pathologies, not related to ammonia exposure. In addition, higher ammonia concentrations did not appear to influence the development of hypo‐osmoregulatory ability during parr‐smolt transformation.     

A growth equation for sole postlarvae (Solea senegalensis Kaup, 1858) in earthen ponds in the region of Tagus and Sado Estuaries (Portugal)

The growth of 1-month-old juvenile sole, Solea senegalensis (Kaup, 1858), was monitored for 6 months in earthen ponds of commercial fish farms located at the Tagus and Sado Estuaries. The postlarvae were introduced into net cages at a density of 50 m⁻². Data obtained from different growth experiments carried out under similar environmental conditions were analysed. To describe the growth of juvenile sole, the comprehensive model proposed by Schnute was fitted to the data. This model provides a better fit than, for instance, the Gompertz model, to the length at age of S. senegalensis juveniles. Seven-month-old sole juveniles have 80% probability of attaining a length of 10.9–11.7 cm and a weight between 11.0 and 13.7 g. The growth equation can be used to predict fish growth under these environmental conditions and thus identify appropriate farm management options.