Assessment of different ionic adjustment strategies in low-salinity water on the growth of Litopenaeus vannamei and microbial community stoichiometry in a synbiotic nursery system

The aim of this study was to evaluate different ionic adjustment strategies in oligohaline water on the growth of Litopenaeus vannamei and C:N:P stoichiometric ratios of the floc microbial community (MC) in synbiotic nursery system. A 35-day culture (2000 PL's/m³) was carried out in 60 L units in a completely randomized experimental design, with three treatments: T1—seawater diluted to a salinity of 2.5 g/L (control), T2—water with a salinity of 2.5 g/L with potassium (K?) adjusted and T3—water at a salinity of 2.5 g/L with its Ca:Mg:K ratio adjusted to 1:3:1, each treatment in triplicates. The MC of flocs and the dissolved fraction (DF) was separated by filtration, where MC >1.6 µm and DF <1.6 µm. The juveniles reached a final weight of 0.40 ± 0.09–0.49 ± 0.04 g, survival above 80% and an average yield of 0.69 ± 0.18–0.81 ± 0.02 kg/m³, without significant differences among the treatments. A stabilizing trend of C:P, C:N and N:P ratios of MC was observed considering the variations of C:N:P in the DF, indicating a homeostatic behaviour of the floc MC, as occurs in systems with high nutrient availability. Our results indicate that the major ions initial concentrations (Ca²⁺: 25.07 mg/L, Mg²⁺: 89.75 mg/L and K?: 25.00 mg/L), total alkalinity 100.00 mg/L and total hardness 433.30 mg/L provide conditions that do not limit shrimp growth in oligohaline water synbiotic nursery system.     

Canopy transpiration of a Pinus canariensis forest at the tree line: implications for its distribution under predicted climate warming

Canopy transpiration (E _c) of a 50-year-old Pinus canariensis Chr. Sm. Ex DC. stand at tree line in Tenerife, Canary Islands, was estimated continuously throughout a year from March 1, 2008, to February 28, 2009, by means of xylem sap flow measurements. E _c varied markedly throughout the entire year generally following the seasonal trends in soil water availability and varied between 0.89 mm day^?1 under the conditions of non-limiting soil water availability and close to zero under soil drought. This is because canopy conductance declined significantly with increasing evaporative demand and thus significantly reduced tree water loss, and this decrease was more pronounced during the soil drought. Total annual E _c was 79.6 mm, which is significantly below the values estimated for other Mediterranean forest ecosystems and even 70 % lower than the value estimated for a P. canariensis forest at 1,650 m a.s.l. where the soil water content was higher than at the tree line site. Therefore, these results highlighted the importance of drought stress in tree line ecotone and should be taken more into account in semiarid tree lines.     

Transgenic wheat plants: a powerful breeding source

Plant breeders are always interested in new genetic resources. In thepast, the sources have been limited to existing germplasm. Geneticengineering now provides the opportunity for almost unlimited strategies tocreate novel resources. As a first stage, the Applied Biotechnology Center(ABC) at CIMMYT developed a method for the mass production of fertiletransgenic wheat (Triticum aestivum L.) that yields plants ready fortransfer to soil in 13–14 weeks after the initiation of cultures, and, over thecourse of a year, an average production of 5–6 transgenic plants per day.CIMMYT elite cultivars are co-bombarded with marker gene and a gene ofinterest with co-transformation efficiencies around 25–30%. The reliabilityof this method opens the possibility for the routine introduction of novelgenes that may induce resistance to diseases and abiotic stresses, allow themodification of dough quality, and increase the levels of micronutrientssuch as iron, zinc, and vitamins. The first group of genes being evaluatedby the ABC are the pathogenesis related (PR) proteins, such as thethaumatin-like protein (TLP) from barley, chitinase, and 1–3-glucanase. Stable integration of the genes in the genome andinheritance in the progeny were determined by phenotypical analyses thatchallenged the plants against a wide range of pathogens. Using these genes,we have recovered more than 1200 independent events (confirmed byPCR and Southern blot analyses) that show responses to the pathogens thatrange from tolerance to hypersensitive reactions. The quantity andanti-fungal activity of the endogenous thaumatin-like proteins were analyzedin T₁ and T₂ progeny plants. Western blot analyses showeddifferent protein patterns of the wheat endogenous TLPs. Preliminary resultsindicated that some patterns increased the resistance of transgenic wheatplants to Alternaria triticina. This relationship is being furtherinvestigated.     

Aneuploidy drives genomic instability in yeast

Aneuploidy decreases cellular fitness, yet it is also associated with cancer, a disease of enhanced proliferative capacity. To investigate one mechanism by which aneuploidy could contribute to tumorigenesis, we examined the effects of aneuploidy on genomic stability. We analyzed 13 budding yeast strains that carry extra copies of single chromosomes and found that all aneuploid strains exhibited one or more forms of genomic instability. Most strains displayed increased chromosome loss and mitotic recombination, as well as defective DNA damage repair. Aneuploid fission yeast strains also exhibited defects in mitotic recombination. Aneuploidy-induced genomic instability could facilitate the development of genetic alterations that drive malignant growth in cancer.     

Granular Vulvovaginitis Syndrome in Nelore pubertal and post pubertal replacement heifers under tropical conditions: role of <Emphasis Type="Italic">Mycoplasma</Emphasis> spp., <Emphasis Type="Italic">Ureaplasma diversum</Emphasis> and BHV-1

In order to determine the role of Mycoplasma spp, Ureaplasma diversum and BHV-1 as causal agents of Granular Vulvovaginitis Syndrome in Nelore heifers raised under tropical conditions and based on the hypothesis that stressful conditions during puberty or breeding season would be a determinant factor for the infection, 340 heifers not vaccinated against BHV-1 were divided in Post-pubertal, in the beginning of the first breeding season, and Pubertal heifers. The vaginal lesion score (VLS) Grade 1 to 4 was giving according to lesion area and severity. Vaginal mucus was used to isolate Mycoplasma spp., Ureaplasma diversum and BHV-1. The predominant VLS was 2. No sample was positive for BHV-1; 48% were positive for Mycoplasma spp., Ureaplasma diversum, or both, with predominance of Ureaplasma diversum. Serum neutralization for BHV-1 showed more positive animals in pubertal group (23%); 3 of the paired sera demonstrated seroconversion. These data indicated that post-pubertal and pubertal Nelore heifers raised under extensive conditions are more susceptible to Mycoplasma spp. and Ureaplasma diversum. The hypothesis that the stress of pubertal period could lead to an acute vaginal infection by HBV-1 was not proofed.     

Bilateral Testicular Mixed Germ Cell-sex Cord-stromal Tumours in a Stallion

An 18-year-old Friesian stallion was examined approximately one week after reportedly presenting scrotal swelling due to torsion of the spermatic cords. Upon presentation no scrotal swelling was noted, the testes were normally oriented, and no abnormalities of the spermatic cords were noted. However, both testes were smaller than expected for a mature stallion and deep palpation revealed that the consistency of the testes was nodular. Ultrasonographic evaluation of the testes revealed diffuse heterogeneous parenchyma with multiple hypoechoic nodular areas. Grossly, the testicular parenchyma was effaced by multiple gray-tan nodules of varying consistency interspersed with gray-white bands of tissue. Microscopic analysis revealed multiple pleomorphic neoplastic foci disseminated throughout both testes. Histological and immunohistochemical features were atypical and consistent with the diagnosis of bilateral testicular mixed germ cell-sex cord stromal tumours. Bilateral testicular tumours and testicular mixed cell tumours are extremely rare in stallions and this is the first report of bilateral testicular mixed germ cell-sex cord-stromal tumours in a stallion. Our findings indicate that certain ultrasonographic characteristics are suggestive of testicular tumour and that immunohistochemistry markers can be used to better characterize testicular neoplasms in stallions.     

Ensemble models of habitat suitability relate chimpanzee (Pan troglodytes) conservation to forest and landscape dynamics in Western Africa

Pan troglodytes verus is considered one of the most endangered primates in the world due to habitat loss or degradation, and it is considered extinct in several regions of West-Africa. This study aims at developing a model that predicts habitat suitability for chimpanzee under different land cover scenarios and supports a multi-temporal analysis of the recent habitat evolution in southern Guinea-Bissau. The model, built using a maximum entropy framework, is spatially explicit, uses eco-geographic variables derived from landscape compositional, structural and functional attributes, and is based on nest location data collected in the field. The results show that the developed model has good levels of reliability and the map produced through its application reveals a current extension of 752 km² of adequate habitat in a 2723 km² study area. Forest related EGVs (ecogeographical variables) had the higher importance for the model production. Habitat suitability maps produced for three dates in the last three decades show that there has been a marked decrease in habitat extension and in connectivity to neighbouring regions. We analyse the implications of these results in possible strategies for the conservation of chimpanzees in Guinea-Bissau.     

Simulating the effects of using different types of species distribution data in reserve selection

In a perfect world, systematic conservation planning would use complete information on the distribution of biodiversity. However, information on most species is grossly incomplete. Two main types of distribution data are frequently used in conservation planning: observed and predicted distribution data. A fundamental question that planners face is - which kind of data is better under what circumstances? We used simulation procedures to analyse the effects of using different types of distribution data on the performance of reserve selection algorithms in scenarios using different reserve selection problems, amounts of species distribution known, conservation targets and costs. To compare these scenarios we used occurrence data from 25 amphibian and 41 reptile species of the Iberian Peninsula and assumed the available data represented the whole truth. We then sampled fractions of these data and either used them as they were, or converted them to modelled predicted distributions. This enabled us to build three other types of species distribution data sets commonly used in conservation planning: “predicted”, “transformed predicted” and “mixed”. Our results suggest that reserve selection performance is sensitive to the type of species distribution data used and that the most cost-efficient decision depends most on the reserve selection problem and on how much we have of the species distribution data. Choosing the most appropriate type of distribution data should start by evaluating the scenario circumstances. While there is no one best approach for every scenario, we discovered that using a mixed approach usually provides an acceptable compromise between species representation and cost.     

Water quality,phytoplankton composition and growth of Litopenaeus vannamei (Boone) in an integrated biofloc system with Gracilaria birdiae (Greville) and Gracilaria domingensis (Kützing)

A 28-day indoor trial was conducted to evaluate the water quality, phytoplankton composition and growth of Litopenaeus vannamei in an integrated biofloc system with Gracilaria birdiae and Gracilaria domingensis. The experimental design was completely randomized with three treatments: control (shrimp monoculture); SB (shrimp and G. birdiae) and SD (shrimp and G. domingensis), all with three replicates. Random sampling was done (6 % of total population per experimental unit) to confirm white spot syndrome Virus (WSSV) infection using nested-PCR analysis due to suspicion of presence of the virus in the experiment (treatment and control groups). Shrimp L. vannamei (2.63 ± 0.10 g) were stocked in experimental tanks at a density of 425 shrimp m^?3, and the Gracilaria was stocked at a biomass of 2.0 kg m^?3. Shrimp mortality began in both the experimental and control groups at 10 days of culture. The integrated biofloc system (shrimp and seaweed) increased settleable solids (by 26–52 %); final weight (by 6–21 %); weekly growth (by 17–43 %); weight gain (by 17–43 %); specific growth rate (by 16–36 %); and yield (by 5–7 %) and decreased feed conversion ratio (by 21–28 %) and Cyanobacteria density about 16 % as compared to the control (shrimp monoculture). The use of red seaweed Gracilaria in an integrated biofloc system can enhance shrimp growth and reduce Cyanobacteria density in the presence of WSSV.     

Protected areas and native freshwater bivalves are not in the same place in south-east Brazil

1. Bivalves are important components of freshwater ecosystems; however, they are also one of the most threatened animal groups, especially members of the order Unionida. The main threats to freshwater bivalves are habitat modification and invasive species. Protected areas are a common way to minimize impacts and preserve native species, but they are rarely designated with a focus on freshwater invertebrates.
2. The main goal of this article was to describe the distribution of freshwater bivalves in the state of Rio de Janeiro, and the relationship between these species and bioclimatic areas, land use and protected areas.
3. Five native and two invasive bivalve species have been reported in Rio de Janeiro. They occur mainly in bioclimatic areas related to the Paraíba do Sul River and Campista Lowlands. The few records of bivalves inside protected areas are in areas of sustainable use that offer a lower level of protection, and frequently in sympatry with invasive bivalves.
4. Thus, the established protected areas in Rio de Janeiro are not adequately effective for freshwater bivalve conservation, and some species remain under threat even within them. Freshwater bivalves thus remain largely unprotected in the state.
5. The development of new protected areas and management plans should consider other faunal groups that are usually ignored, such as freshwater bivalves, to achieve more inclusive and effective protection.