Genetic variation among and within populations of <Emphasis Type="Italic">Cordia africana</Emphasis> in seed size and germination responses to constant temperatures

Cordia africana Lam. is a commercial timber species that grows naturally throughout sub-Saharan Africa and tropical Arabia. At present very little is known about genetic variation in this species and baseline information is needed to initiate improvement programs in Ethiopia. Thus, the objectives of the study were to quantify the inter- and intra-population variations in seed size traits and germination responses to different constant temperature regimes. Seeds were collected from 30 open-pollinated families within each of the five populations representing the natural distribution of the species in Ethiopia. To examine seed size variations, seed length, seed width, and 1,000-seed weight were quantified. Inter- and intra-population variations in seed germination were investigated under different constant temperature regimes from 20 to 35°C in climate chambers. Significant variations in seed length, width and weight were detected both at inter- and intra-population levels, and family heritabilities of 0.63–0.76 showed that much of the phenotypic variation in seed size traits were additive genetic variation. Significant variation in germination was also found among and within populations as well as between the different constant temperature regimes. Generally the variation in germination was considerably higher within population than between populations. The optimal temperature for germination of C. africana seeds was 25–30°C with family heritabilities for germination ranging between 0.20 and 0.33, depending on the germination temperature.     

Protocol: A high-throughput DNA extraction system suitable for conifers

Background  

High throughput DNA isolation from plants is a major bottleneck for most studies requiring large sample sizes. A variety of protocols have been developed for DNA isolation from plants. However, many species, including conifers, have high contents of secondary metabolites that interfere with the extraction process or the subsequent analysis steps. Here, we describe a procedure for high-throughput DNA isolation from conifers.     

Wild ostrich (<Emphasis Type="Italic">Struthio camelus</Emphasis>) ecology and physiology

This work discusses some of the important considerations of wild ostrich evolution, behaviour and ecology, as items included in ostrich production. In the process considerable research was conducted by collating information from peer-reviewed papers; textbooks; manuals; and PubMed and Agricola searches. Selected areas reviewed included activity of ostriches; feeding and water needs; sexual maturity; egg laying and natural incubation; selected physiological parameters; and predation. There is an immediate and urgent need to conserve and protect the rapidly declining populations of wild ostriches with the committed involvement of governments and funding bodies.     

Coupled Effects of Electrical Stimulation and Antibiotics on Microbial Community in Three-Dimensional Biofilm-Electrode Reactors

Antibiotics are often misused or overused, resulting in large residue inputs in the environment. Electricity and antibiotics were regarded as potentially important factors, which impact on the microbial community during treatment of antibiotics in three-dimensional biofilm-electrode reactors (3D-BERs). Unfortunately, only a few studies have been reported yet. Four 3D-BERs and one 3D-BR (reactor with biological sludge and no voltage) were designed to assess the effect of low current, sulfamethoxazole (SMX), and tetracycline (TC) on microbial populations. The 3D-BERs achieved excellent removal efficiencies of 72.20–93.52 and 82.61–95.80% for SMX and TC, respectively. Microorganisms were classified into 58 phyla, 125 classes, 166 orders, 187 families, and 220 genera. Proteobacteria held the overwhelming predominance, followed by Bacteroidetes, Chloroflexi, Actinobacteria, Verrucomicrobia, Firmicutes, and Acidobacteria. The 3D-BERs achieved higher richness of microbial composition compared with the 3D-BR. Microbial communities and relative abundance at the phyla level were affected by low current. The microbial communities in the 3D-BERs were similar at the genus level, even with different antibiotic concentrations. However, the relative abundances and compositions of the microbial communities decreased during the treatment of antibiotics. To increase the performance of 3D-BERs, the function of microorganisms should be investigated in future studies.     

Effectiveness of Natural Compounds on DNA Damage in <Emphasis Type="Italic">Coris julis</Emphasis> (Linneaus 1758) from a Polluted Marine Area

The evaluation of DNA damage in aquatic organisms represents one of the most widely used biomarkers in the assessment and monitoring of marine pollution. Our previous research highlighted the presence of DNA damage in hepatic nuclei and blood cells of Coris julis specimens collected from Augusta harbor (Syracuse, Italy), a site highly polluted. In this work, we investigated on the ability of different natural compounds with antioxidant and immunostimulating properties, such as resveratrol (50 μM, 100 μM), amygdalin (100 μM, 200 μM), and Urtica dioica roots extract (50 and/or 100 μg/ml), in reducing DNA damage of C. julis. Blood cells were analyzed by atypical cellular comet assay. The results confirmed that Augusta specimens are the most damaged and showed that resveratrol, followed by amygdalin and U. dioica roots extract, drastically reduced DNA damage. This finding evidences the effectiveness of three natural compounds for DNA protection suggesting the possible use of feed enriched with antioxidant compounds in aquaculture practices for organisms damaged by natural and anthropic insults.     

A Greener UV and Peroxide-Based Chemical Oxygen Demand Test

Water quality assessment typically includes the determination of chemical oxygen demand (COD) by oxidation of organic matter with Cr(VI) in an acidic medium followed by digestion. Unfortunately, the required reagents are harmful and the reaction times are rather long. We investigated earlier the use of H₂O₂ as a more environmentally friendly oxidizing agent to replace the hazardous chromates. In the present study, we have furthered this possibility by incorporating the use of H₂O₂ in the presence of UV light. A protocol has been devised and tested with standards and real samples that replaces toxic Cr(VI), halves the amount of silver sulfate required, and greatly reduces the necessary reaction time, thus yielding a faster and more environmentally sound method.     

Photocatalytic Removal of the Antibiotic Cefotaxime on TiO<Subscript>2</Subscript> and ZnO Suspensions Under Simulated Sunlight Radiation

This study presents the main results about the removal of the antibiotic cefotaxime (CTX) under simulated sunlight radiation using heterogeneous photocatalysis with titanium dioxide (TiO₂) and zinc oxide (ZnO) in aqueous solutions. The effects of pH and catalyst initial load on pollutant removal were assessed considering the response surface methodology and a central composite circumscribed experimental design, which allowed to determine the optimized conditions that lead to a higher substrate elimination. Experimental results indicated that evaluated parameters have a significant effect on antibiotic removal in both TiO₂ and ZnO suspensions. In addition, the role of photogenerated holes, hydroxyl, and superoxide anion radicals on CTX degradation was evaluated to clarify the reaction mechanism. Finally, analysis of the dissolved organic carbon content in solutions and the antibacterial activity of treated samples showed that photocatalytic treatments were able to reduce a considerable portion of the organic matter present in the systems and its antimicrobial activity.     

A General Approach to Model Movement in (Highly) Fragmented Patch Networks

Landscape heterogeneity can often be represented as a series of discrete habitat or resource patches surrounded by a matrix of non-habitat. Understanding how animals move in such networks of patches is important for many theoretical and applied questions. The probability of going from one patch to another is affected in a non-trivial way by the characteristics and location of other patches in the network. Nearby patches can compete as possible destinations, and a particular patch can be shadowed by neighboring patches. We present a way to account for the effects of the spatial configuration of patches in models of space use where individuals alternate between spending time in a patch and moving to other patches in the network. The approach is based on the original derivation of Ovaskainen and Cornell (J Appl Probab 40:557–580, 2003) for a diffusion model that considered all possible ways in which an individual leaving a particular patch can eventually reach another patch before dying or leaving the patch network. By replacing the theoretical results of Ovaskainen and Cornell by other appropriate functions, we provide generality and thus make their approach useful in contexts where diffusion is not a good approximation of movement. Furthermore, we provide ways to estimate time spent in the non-habitat matrix when going from patch to patch and implement a method to incorporate the effect of the history of previous visits on future patch use. We present an MCMC way to fit these models to data and illustrate the approach with both simulated data and data from sheep moving among seasonally flooded meadows in northern Patagonia.Supplementary materials accompanying this paper appear online.